Title of Invention	A SINGLE-USE SYRINGE
Abstract	The invention relates to a single-use syringe comprises a barrel (2) having front and rear passageways (22,21) and a shoulder (24) disposed therebetween, a plunger (4) movable in the rear passageway (21), a carrier (5) having a tail portion (517) extending from a front end wall (41) of the plunger (4), and pushing and retained regions (516, 527) formed forwardly of the tail portion (517), and a deformable sealing member (6) in fluid- tight and slidable engagement with the barrel (2), the sealing member (6) includes an inner surrounding wall surface (617) with a yielding segment (610) engaging the pushing region (516), and a retaining segment (613) in frictional engagement with the retained region (527) by a frictional force so as to confine a fluid-tight surrounding area. The frictional force is diminished when the yielding segment (610) is depressed by the pushing region (516) so as facilitate release of the retained region (527) from the retaining segment (613), thereby disrupting the fluid-tightness of the surrounding area and rendering the syringe unreusable.

Title of Invention

A SINGLE-USE SYRINGE

Abstract

The invention relates to a single-use syringe comprises a barrel (2) having front and rear passageways (22,21) and a shoulder (24) disposed therebetween, a plunger (4) movable in the rear passageway (21), a carrier (5) having a tail portion (517) extending from a front end wall (41) of the plunger (4), and pushing and retained regions (516, 527) formed forwardly of the tail portion (517), and a deformable sealing member (6) in fluid- tight and slidable engagement with the barrel (2), the sealing member (6) includes an inner surrounding wall surface (617) with a yielding segment (610) engaging the pushing region (516), and a retaining segment (613) in frictional engagement with the retained region (527) by a frictional force so as to confine a fluid-tight surrounding area. The frictional force is diminished when the yielding segment (610) is depressed by the pushing region (516) so as facilitate release of the retained region (527) from the retaining segment (613), thereby disrupting the fluid-tightness of the surrounding area and rendering the syringe unreusable.

Full Text	This invention relates to a single-use syringe, more particularly to a single-use syringe, in which fluid-tightness of a barrel is disrupted when the syringe is displaced to a disposal position so as to render the syringe unreusable. Referring to Figs . 1 and 2, a conventional single-use syringe is shown to include a barrel 11 which has an axially extending surrounding wall 113 defining front and rear passageways 112, 111, and a surrounding shoulder 114 disposed between the front and rear passageways 112 , 111, a needle assembly 12 which is sleeved on a front opened end of the surrounding wall 113, a plunger 13 which is disposed to be movable in and along the rear passageway 111 and which has a taperedhead 131 formed ona front end thereof, a deformable sealing member 14 which is retainingly sleeved on the tapered head 131, which is in fluid-tight and slidable engagement with the surrounding wall 113 at the rear passageway 111, and which has an axially extending vent hole 132 communicated with the ambient air, and a plug 15 which is detachably connected to the deformable sealing member 14 and which closes the vent hole 132. An inner surface of the surrounding wall 113 has a retaining ring 115 formed adjacent to the shoulder 114. The plug 15 has an anchoring portion 151 projecting forwardly and outwardly of the deformable sealing member 14 such that, subsequent to completion of injection, the deformable sealing member 14 is brought to abut against the shoulder 114 and the anchoring portion 151 is engaged with the retaining ring 115 to thereby permit disengagement of the plug 15 from the deformable sealing member 14 when the plunger 13 is pulled rearwardly, and to thereby disrupt the fluid-tightness of the vent hole 132 for rendering the syringe unreusable. However, when the anchoring portion 151 is forced to be engaged with the retaining ring 115, the frictional force between the plug 15 and the deformable sealing member 14 is increased, which may be greater than the force of engagement between the anchoring portion 151 and the retaining ring 115, thereby adversely affecting separation of the plug 15 from the deformable sealing member 14. Moreover, formation of the retaining ring 115 on the inner surface of the barrel 11 is inconvenient during manufacture. An object of the present invention is to provide a single-use syringe which has friction diminishing means to facilitate disruption of fluid-tightness of a surrounding area in a barrel when the syringe is displaced to a disposal position so as to render the syringe unreusable. According to this invention, the single-use syringe includes a barrel having an inner surrounding barrel surface which surrounds an axis in a longitudinal direction, and which includes a rear larger-diameter portion that defines a rear passageway therein, a front smaller-diameter portion that defines a front passageway therein to be in fluid communication with a needle assembly and that is opposite to the rear larger-diameter portion in the longitudinal direction, and a surrounding shoulder that is disposed between the rear larger-diameter portion and the front smaller-diameter portion. The rear passageway terminates at a rearward opening. A plunger is disposed to be movable in the rear passageway along the larger-diameter portion. The plunger has a front end wall which confronts the front passageway, and a rear end wall which is disposed opposite to the front end wall and which extends outwardly of the rearward opening to be manually operable. A carrier includes a tail portion which extends from the front end wall along the axis, a head portion which is disposed opposite to the tail portion in the rear passageway along the axis, and an intermediate surrounding portion which is interposed between the tail and head portions and which surrounds the axis. The intermediate surrounding portion has a pushing region and a retained region which are proximate to the tail and head portions, respectively. A hollow deformable sealing member includes a head end wall which has a periphery and which confronts the surrounding shoulder, an upper sealing end which is integrally formed with the periphery of the head end wall and which is in fluid-tight and slidable engagement with the rear larger-diameter portion, and a deformable surrounding wall which extends from the upper sealing end rearwardly and which terminates at a surrounding trailing end that is configured to drag on the rear larger-diameter portion. The deformable surrounding wall has an outer surrounding wall surface which is spaced apart from the rear larger-diameter portion in radial directions when the syringe is in a position of use, thereby vesting the deformable surrounding wall with an increased radial flexibility, and an inner surrounding wall surface which is opposite to the outer surrounding wall surface in radial directions. The inner surrounding wall surface has a yielding segment which is engaged with and which is depressed by the pushing region radially when the carrier is moved in a longitudinal direction relative to the deformable surrounding wall so as to bring the head end wall to abut against and to be retained at the surrounding shoulder, thereby displacing the syringe from the position of use to a disposal position, and a retaining segment which is in a f rictional engagement with the retained region by virtue of a frictional force so as to confine, in cooperation with the yielding segment and the pushing region, a fluid-tight surrounding area, and which is configured such that the frictional force is diminished so as to facilitate release of the retained region from the retaining segment when the yielding segment is depressed by the pushing region, thereby disrupting the fluid-tightness of the surrounding area and rendering the syringe unreusable. Other features and advantages of the present invention will become apparent in the following detailed description of the preferred embodiments of the invention, with reference to the accompanying drawings, in which: Fig. 1 is a sectional view of a conventional single-use syringe; Fig. 2 is a sectional view of the conventional single-use syringe of Fig. 1 after use; Fig. 3 is an exploded sectional view of the first preferred embodiment of a single-use syringe according to this invention; Fig. 4 is a sectional view of the first preferred embodiment during an injection stroke; Figs . 5 is a sectional viewof the first preferred embodiment, showing the state of completion of the injection stroke; Figs. 6 to 8 are sectional views of the first preferred embodiment, showing an operation of disrupting fluid-tightness of the syringe; Fig. 9 is a sectional view of the second preferred embodiment of a single-use syringe according to this invention; Fig. 10 is a sectional view of a modified form of the second preferred embodiment shown in Fig. 9; Fig. 11 is a sectional view of the third preferred embodiment of a single-use syringe according to this invention; Figs. 12 and 13 are sectional views of the third preferred embodiment, showing an operation of disrupting fluid-tightness of the syringe; Fig. 14 is a sectional view of a modified form of the third preferred embodiment shown in Fig. 11; Fig. 15 is a sectional viewof the fourthpref erred embodiment of a single-use syringe according to this invention; Fig. 16 is a sectional viewof the fourthpref erred embodiment after disruption of fluid-tightness of the syringe; Fig. 17 is a sectional view of a modified form of the fourth preferred embodiment shown in Fig. 15; Fig. 18 is a sectional view of another modified form of the fourth preferred embodiment shown in Fig. 15; Fig. 19 is a sectional view of the fifth preferred embodiment of a single-use syringe according to this invention; Figs. 20 and 21 are sectional views of the fifth preferred embodiment, showing an operation of disrupting fluid-tightness of the syringe; Fig. 22 is a sectional view of the sixth preferred embodiment of a single-use syringe according to this invention; Fig. 23 is a sectional view of a modified form of the sixth preferred embodiment shown in Fig. 22; Fig. 24 is a sectional view of the seventh preferred embodiment of a single-use syringe according to this invention; Fig. 25 is a sectional view of a modified form of the seventh preferred embodiment shown in Fig. 24; Fig. 26 is a sectional view of another modified form of the seventh preferred embodiment shown in Fig. 24; Fig. 27 is an exploded sectional viewof the eighth preferred embodiment of a single-use syringe according to this invention; Fig. 28 is an exploded sectional view of the ninth preferred embodiment of a single-use syringe according to this invention; Fig. 2 9 is a fragmentary sectional view of the tenth preferred embodiment of a single-use syringe according to this invention; Fig. 3 0 is a sectional view of the tenth preferred embodiment after disruption of the fluid-tightness of the syringe; Fig. 31 is a sectional view of a modified form of the tenth preferred embodiment shown in Fig. 29; Fig. 32 is a fragmentary sectional view of the eleventh preferred embodiment of a single-use syringe according to this invention; Fig. 33 is a sectional view of the eleventh preferred embodiment after disruption of the fluid-tightness of the syringe; Fig. 34 is a sectional view of a modified form of the eleventh preferred embodiment shown in Fig. 32; Fig. 35 is a sectional view of another modified form of the eleventh preferred embodiment shown in Fig. 32; Fig. 3 6 is a fragmentary sectional view of the twelfth preferred embodiment of a single-use syringe according to this invention; Fig. 3 7 is a sectional view of the twelfth preferred embodiment after disruption of the fluid-tightness of the syringe; Fig. 38 is a sectional view of a modified form of the twelfth preferred embodiment shown in Fig. 36; and Fig. 39 is a sectional view of another modified form of the twelfth preferred embodiment shown in Fig. 36. Before the present invention is described in greater detail, it should be noted that same reference numerals have been used to denote like elements throughout the specification. Referring to Figs. 3 and 4, the first preferred embodiment of a single-use syringe according to the present invention is shown to be used with a needle assembly 3 . The needle assembly 3 includes a needle hub 31 and a needle cannula 32 . The syringe comprises a barrel 2, a plunger 4, a carrier 5, and a hollow deformable sealing member 6. The barrel 2 has an inner surrounding barrel surface 23 which surrounds an axis (X) in a longitudinal direction, and which includes a rear larger-diameter portion that defines a rear passageway 21 therein, a front smaller-diameter portion that defines a front passageway 22 therein to be in fluid communication with the needle assembly 3 in a known manner, and that is opposite to the rear larger-diameter portion in the longitudinal direction, and a surrounding shoulder 24 that is disposed between the rear larger-diameter portion and the front smaller-diameter portion. The front and rear passageways 22,21 respectively terminate at forward and rearward openings 231,232. The plunger 4 is disposed to be movable in the rear passageway 21 along the larger-diameter portion. The plunger 4 has a front end wall 41 which confronts the front passageway 22, and a rear end wall 42 which is disposed opposite to the front end wall 41 along the longitudinal direction and which extends outwardly of the rearward opening 232 to be manually operable. The carrier 5 includes a tail portion 517 which extends from the front end wall 41 along the axis (X) , a head portion 523 which is disposed in the rear passageway 21 opposite to the tail portion 517 and along the axis (X) , and an intermediate surrounding portion which is interposed between the tail and head portions 517,523 and which surrounds the axis (X). The intermediate surrounding portion includes a tubular pushing segment 51 and a tubular retained segment 52 . The pushing segment 51 is coupled and formed integrally with the tail portion 517, and terminates at an opened end 513. The pushing segment 51 has an inner surrounding engaging region 514 which extends in the longitudinal direction to be communicated with the opened end 513 and which defines a cavity 511, and a pushing region 516 which is disposed radially and outwardly of the inner surrounding engaging region 514. Preferably, the pushing segment 51 is converged from the pushing region 516 to the opened end 513. A vent hole 515 is formed in the pushing segment 51, and extends along the axis (X) to be in fluid communication with the cavity 511. The retained segment 52 has an outer surrounding retained wall 521 which extends from the head portion 523 in the longitudinal direction to terminate at an outer engaging end 524 and which is insertable into the cavity 511. The outer surrounding retained wall 521 has two annular grooves 525,526, and a projecting retained region 527 formed between the annular grooves 525,526. In a position of use, as shown in Fig. 4, the outer engaging end 524 is frictionally engaged with the inner surrounding engaging region 514 such that the annular grooves 525,526 and the retained region 527 are projected outwardly of the pushing segment 51. The deformable sealing member 6 includes a head end wall 613 which has a periphery and which confronts the surrounding shoulder 24, an upper sealing end 615 which is integrally formed with the periphery of the head end wall 613 and which is in fluid-tight and slidable engagement with the rear larger-diameter portion, and a deformable surrounding wall 612 which extends from the upper sealing end 615 rearwardly and which terminates at a surrounding trailing end 616 that is configured to drag on and to be in fluid-tight engagement with the rear larger-diameter portion. The deformable surrounding wall 612 has an outer surrounding wall surface 622 which is spaced apart from the rear larger-diameter portion in radial directions when the syringe is in the position of use so as to cooperative with the upper sealing end 615 and the surrounding trailing end 616 to define an annular compressible chamber 621 thereamong, thereby vesting the deformable surrounding wall 612 with an increased radial flexibility. The deformable surrounding wall 612 further has an inner surrounding wall surface 617 opposite to the outer surrounding wall surface 622 in radial directions. The inner surrounding wall surface 617 has a yielding segment 610 which is engaged with and which is depressed by the pushing region 516 radially when the carrier 5 is moved in a longitudinal direction relative to the deformable surrounding wall 612 so as to bring the head end wall 613 to abut against and to be retained at the surrounding shoulder 24, thereby displacing the syringe from the position of use to a disposal position, and a retaining segment 618 which is in a first frictional engagement with the retained region 527 by virtue of a first frictional force so as to confine, in cooperationwith the yielding segment 610 and the pushing region 516, a fluid-tight surrounding area. Thus, referring to Figs. 5 to 7, subsequent to the abutment of the head end wall 613 against the surrounding shoulder 24, the yielding segment 610 is depressed by the pushing region 516 radially and outwardly to result in deformation of the deformable surrounding wall 612, which moves the inner surrounding wall surface 617 radially and towards the rear larger-diameter portion so as to diminish the first frictional force, thereby disrupting the fluid-tightness of the surrounding area and rendering the syringe unreusable. Subsequent to the disruption of the fluid-tightness of the surrounding area, the head portion 523 is blocked by the surrounding shoulder 24 from moving further so as to permit movement of the pushing segment 51 relative to the retained segment 52 such that the outer surrounding retained wall 521 is brought into a second f rictional engagement with the inner surrounding engaging region 514 . Meanwhile, the deformable surrounding wall 612 is deformed to squeeze the air out of the annular compressible chamber 621 so that the outer surrounding wall surface 622 is tightly attached to the rear larger-diameter portion. Subsequently, referring to Fig. 8, when the carrier 5 is moved rearwards by the plunger 4 towards the rearward opening 232, the carrier 5 is disengaged from the deformable sealing member 6. Referring to Fig. 9, the second preferred embodiment of a single-use syringe according to this invention is shown to be similar to the previous embodiment in construction. The syringe of this embodiment further includes a passageway interrupting member 62 3 which is integrally formed with the head end wall 613 of the deformable sealing member 6 such that once the fluid-tightness of the surrounding area is disrupted, the passageway interrupting member 62 3 is forced by the head end wall 613 to extend into the front passageway 22. The passageway interrupt ing member 623 has a plurality of f rictional ribs 625 disposed thereon, and a diameter larger than that of the front passageway 22 so as to be in a frictional engagement with the front smaller-diameter portion. Thus, the diminution of the first frictional force enables disengagement of the retained region 527 from the retaining segment 618, thereby facilitating disengagement of the deformable sealing member 6 from the carrier 5 when the carrier 5 is moved rearwardly by the plunger 4 toward the rearward opening 232 . Alternatively, referring to Fig. 10, the passageway interrupting member 62 3 has a longer length so as to plug the entire front passageway 22 for minimizing the amount of medication remaining in the barrel 2. Referring to Figs. 11 to 13, the third preferred embodiment of a single-use syringe according to this invention is shown to be similar to the first preferred embodiment in construction. The carrier 5 of this embodiment further includes a projection member 53 which is integrally formed with the head portion 523 and which extends forwardly through a slit 619 in the head end wall 613 of the deformable sealing member 6. The projection member 53 has a diameter slightly smaller than that of the front passageway 22, and is moved with the head portion 523 by the plunger 4 to be inserted into the front passageway 22 in an injection stroke for reducing the amount of medication left in the barrel 2. When the carrier 5 is moved rearwardly, the projection member 53 is moved to disengage from the head end wall 613 of the deformable sealing member 6 so as to completely- disrupt the fluid-tightness of the surrounding area. In a modified form of the embodiment, as shown in Fig. 14, the projection member 53 has a longer length so as to plug the entire front passageway 22 for minimizing the amount of medication remaining in the barrel 2. Referring to Figs . 15 and 16, the fourth preferred embodiment of a single-use syringe according to this invention is shown to be similar to the first preferred embodiment in construction. The syringe of this embodiment further includes a passageway interrupting member 63 which is integrally formed with the head portion 523 of the carrier 5 and which projects outwardly of the head end wall 613 of the deformable sealing member 6 through a slit 619 in the head end wall 613 . The passageway interrupting member 63 has a plurality of frictional ribs 631 formed thereon, and a diameter larger than that of the front passageway 22 so as to be; in frictional engagement with the front smaller-diameter portion and so as to enable the head portion 523 to abut against the head end wall 613 . When the tail portion 517 of the carrier 5 is moved rearwardly by the plunger 4 toward the rearward opening 232, the pushing segment 51 is disengaged from the retained segment 52 to completely disrupt the fluid-tightness of the surrounding area for rendering the syringe unreusable. Referring to Fig. 17, a modified form of the syringe of the fourth preferred embodiment is shown to comprise a passageway interrupting member 64 which has a length sufficient to fully plug the front passageway 22. The passageway interrupting member 64 has a rear end segment 642 formed with a plurality of frictional ribs 641, and a front end segment 643 with a diameter smaller than that of the front passageway 22. Referring to Fig. 18, another modified form of the syringe of the fourth preferred embodiment is shown to comprise a passageway interrupting member 65 which has two prongs 651 that project outwardly of the forward opening 231 to acquire a biasing force so as to reinforce plugging-in engagement of the passageway interrupting member 65 with the front smaller-diameter portion. Referring to Figs. 19 to 21, the fifth preferred embodiment of a single-use syringe according to this invention is shown to be similar to the first preferred embodiment in construction. In this embodiment, the carrier 5 and the plunger 4 are an integrally formed structure. The carrier 5 includes a tail portion 517 with a plurality of rib plates 518, and an intermediate surrounding portion extending forwardly from the tail portion 517 to terminate at a head portion 523. The intermediate surrounding portion has a pushing region 516 to depress the yielding segment 610 of the deformable sealing member 6, and a retained region 52 7 in frictional engagement with the retaining segment 618 of the deformable sealing member 6. The carrier 5 has an insert bore 56 extending from the head portion 523 along the axis (X) to acquire a radial flexibility so as to facilitate movement of the carrier 5 relative to the deformable sealing member 6 after abutment of the head end wall 613 against the surrounding shoulder 24. Referring to Figs . 22 and 23 , the sixth preferred embodiment of a single-use syringe according to this invention is shown to be similar to the fifth preferred embodiment in construction. The syringe of this embodiment further includes a passageway interrupting member 623 which is integrally formed with the head end wall 613 of the deformable sealing member 6, and which has a plurality of frictional ribs 625 disposed thereon and having a diameter larger than that of the front passageway 22 so as to be in a frictional engagement with the front smaller-diameter portion, thereby facilitating disengagement of the deformable sealing member 6 from the carrier 5 when the carrier 5 is moved rearwardly by the plunger 4 . Alternatively, referring to Fig. 23, the passageway interrupting member 623 may have a longer length so as to plug the entire front passageway 22 for minimizing the amount of medication remaining in the barrel 2. Referring to Figs . 24 to 26, the seventh preferred embodiment of a single-use syringe according to this invention is shown to be similar to the fifth preferred embodiment in construction. In this embodiment, the head portion 523 of the carrier 5 has an inner peripheral grip wall 55 which defines an insert bore 56 extending along the axis (X) through the intermediate surrounding portion such that the inner peripheral grip wall 55 acquires a radial flexibility, thereby yielding radially and towards the axis (X) to the first frictional force of the first frictional engagement between the retaining segment 618 and the retained region 527. The syringe further comprises a passageway interrupting member 67 . The passageway interrupting member 67 has a gripped end 674 which is retained in the insert bore 56 when the inner peripheral grip wall 55 yields to the first frictional force and which has a plurality of frictional ribs 673 formed thereon, a plug head 677 which is opposite to the gripped end 674 in the longitudinal direction and which extends f orwardly and outwardly of the head end wall 613 through a slit 619, and an abutment ring 672 which is disposed between the gripped end 674 and the plug head 677. The plug head 677 has a plurality of frictional ribs 675 formed thereon. Therefore, once the fluid-tightness of the surrounding area is disrupted, the plug head 677 plugs the front passageway 22 with the abutment ring 672 abutting against the head end wall 613 . Referring to Fig. 25, in a modified form of the seventh preferred embodiment, the passageway interrupting member 68 has a length sufficient to fully plug the front passageway 22 for minimizing the amount of medication remaining in the barrel 2 . The plug head 686 of the passageway interrupting member 68 has a rear segment formed with a plurality of frictional ribs 685, and a front end segment 687 with a diameter smaller than that of the front passageway 22. Alternatively, in another modified form of the syringe of the seventh preferred embodiment shown in Fig. 26, the passageway interrupting member 69 has two prongs 695 that project outwardly of the forward opening 231 to acquire a biasing force to reinforce plugging-in engagement of the passageway interrupt ing member 69 with the front smaller-diameterportion. Referring to Fig. 27, the eighth preferred embodiment of a single-use syringe according to this invention is shown to be similar to the seventh preferred embodiment in construction. In this embodiment, each of the passageway interrupting members 67,68,69 that are selectively insertable into the insert bore 56 is not formed with an abutment ring so as to simplify the structure thereof. Referring to Fig. 28, the ninth preferred embodiment of a single-use syringe according to this invention is shown to be similar to the eighth preferred embodiment in construction. As shown, the pushing region 516 of the carrier 5 has a relatively smooth surface. Although the yielding segment 610 of the deformable sealing member 6 is depressed by the pushing region 516 so that the deformable surrounding wall 612 is partly attached to the rear larger-diameter portion of the barrel 2, thedeformable seal ing member 6 maybe retained by the passageway interrupting member 67,68,69 after the carrier 5 is moved rearwardly. Referring to Figs . 29 and 3D, the tenth preferred embodiment of a single-use syringe according to this invention is shown to be similar to the sixth preferred embodiment in construction. In this embodiment, the carrier 5 has two annular teeth formed on the intermediate surrounding portion to respectively serve as the pushing region 516 and the retained region 527. The deformable surrounding wall 612 has two annular grooves formed in the inner surrounding wall surface to respectively serve as the yielding segment 610 and the retaining segment 618, and a moving space 66 formed forwardly of the annular grooves. Therefore, subsequent to the abutment of the head end wall 613 against the surrounding shoulder 24 , the carrier 5 can be forced to move forwardly relative to the deformable sealing member 6 to insert, into the moving space 66 so as to diminish the first frictional force upon the first frictional engagement, of the retained region 527 with the retaining segment 618, thereby disrupting the fluid-tightness of the surrounding area for rendering the syringe unreusable. Alternatively, the passageway interrupting member 623 may have a length sufficient to plug the entire front passageway 22 for minimizing the; amount of medication remaining in the barrel 2, as shown in Fig. 31. Referring to Figs. 32 and 33, the eleventh preferred embodiment of a single-use syringe according to this invention is shown to be similar to the tenth preferred embodiment in construction. In this embodiment, the passageway interrupting member 67 has a gripped end 674 which is retained in the insert bore 56 when the inner peripheral grip wall 55 yields to the first frictional force of the first frictional engagement between the retaining segment 618 and the retained region 527 and which has a plurality of frictional ribs 673 formed thereon, and a plug head 677 which extends forwardly and outwardly of the head end wall 613 through a slit 619 in the head end wall 613, and which has a plurality of frictional ribs 675 formed thereon. The diminution of the first frictional force upon the first frictional engagement of the retained region 52 7 with the retaining segment 618 lessens the degree of yielding towards the axis (X) so as to permit the inner peripheral grip wall 55 to release the gripped end 674, thereby permitting the plug head 677 to be retained in the front passageway 22 when the carrier 5 is moved in the longitudinal direction relative to the deformable surrounding wall 612. Furthermore, the intermediate surrounding portion of the carrier 5 further has a pulling region 57 which is disposed rearwardly of the pushing region 516. The inner surrounding wall surface of the deformable surrounding wall 612 has a pulled segment 62 which is disposed between the yielding segment 610 and the retaining segment 618. Therefore, subsequent to the movement of the carrier 5 into the moving space 66 to disrupt the fluid-tightness of the surrounding area, the pulling region 57 is displaced to abut against the pulled segment 62 such that the pulling region 57 is forced by a rearward movement of the carrier 5 to depress the pulled segment 62 to move towards the rearward opening 232, thereby permitting movement of the deformable sealing member 6 with the carrier 5 so as to bring the plug head 677 to disengage from the head end wall 613 of the deformable sealing member 6 when the plug head 677 is retained in the front passageway 22. In the modified form of the eleventh preferred embodiment as shown in Fig. 34, the passageway interrupting member 68 has a length sufficient to plug the entire front passageway 22 for minimizing the amount of medication remaining in the barrel 2. The plug head 686 of the passageway interrupting member 68 has a rear segment formed with a plurality of frictional ribs 685, and a front end segment 687 with a diameter smaller than that of the front passageway 22 . Referring to Fig. 35, in another modified form of the syringe of the eleventh preferred embodiment, the passageway interrupting member 69 which has two prongs 695 that project outwardly of the forward opening 231 to acquire a biasing force to reinforce plugging-in engagement of the passageway interrupting member 69 with the front smaller-diameter portion. Referring to Figs. 36 and 37, the twelfth preferred embodiment of a single-use syringe according to this invention is shown to be similar to the eleventh preferred embodiment in construction. In this embodiment, the intermediate surrounding portion of the carrier 5 includes a tubular pushing segment 51 with the pushing region 516, and a tubular retained segment 52 with the retained region 527. The pushing segment 51has an insert bore 56 extending along the axis (X) . The retained segment 52 has a grip portion 52 8 which is retained in the insert bore 56, and which has a plurality of frictional ribs 529 formed thereon. The passageway interrupting member 67 is integrally formed with the head portion 523, extends forwardly and outwardly of the head end wall 613 through the slit 619, and has a plurality of frictional ribs 675 formed thereon. Therefore, subsequent to the disruption of the fluid-tightness of the surrounding area, the head port ion 523 is brought to abut cigainst the head end wall 613 so as to permit the passageway interrupting member 67 to plug the front passageway 22. In the modified form of the twelfth preferred embodiment as shown in Fig. 38, the passageway interrupting member 68 has a length sufficient to plug the entire front passageway 22 for minimizing the amount of medication remaining in the barrel 2 . The passageway interrupting member 68 has a rear segment formed with a plurality of frictional ribs 685, and a front end segment 687 with a diameter smaller than that of the front passageway 22. Referring to Fig. 39, in another modified form of the syringe of the twelfth preferred embodiment, the passageway interrupting member 69 has two prongs 695 that project outwardly of the forward opening 231 to acquire a biasing force to reinforce plugging-in engagement of the passageway interrupt ing member 69 with the front smaller-diameter portion. As illustrated, in the syringe of this invention, during displacement of the syringe from the position of use to the disposal position, the first frictional force, by which the retaining segment 618 of the deformable sealing member 6 is in frictional engagement with the retained region 52 7 of the carrier 5, is diminished when the yielding segment 610 is depressed by the pushing region 516, thereby facilitating release of the retained region 527 from the retaining segment 618 to ensure disruption of the fluid-tightness of the surrounding area for rendering the syringe unreusable . Moreover, the passageway interrupting member 623,63,64,65,67,68,69 is provided to plug the front passageway 22 of the barrel 2 even when the plunger 4 is moved rearwardly, thereby preventing the syringe from being reused. Also, the passageway interrupting member 623,63,64,65,67,68,69 can be coupled with one of the head portion 523 of the carrier 5 and the head end wall 613 of the deformable sealing member 6. Therefore, the barrel 2, the carrier 5, the plunger 4, and the passageway interrupting member can be fabricated conveniently without the need to modify the barrel 2. We Claim: 1. A single-use syringe adapted to be used with a needle assembly (3), comprising: a barrel (2) having an inner surrounding barrel surface (23) which surrounds an axis (X) in a longitudinal direction, and which comprises a rear larger-diameter portion that defines a rear passageway (21) therein, a front smaller-diameter portion that defines a front passageway (22) therein to be in fluid communication with the needle assembly (3) and that is opposite to said rear larger-diameter portion (21) in the longitudinal direction, and a surrounding shoulder (24) that is disposed between said rear larger-diameter portion and said front smaller-diameter portion, said rear passageway (21) terminating at a rearward opening (232); and a plunger (4) which is disposed to be movable in said rear passageway (21) along said larger-diameter portion, said plunger (4) having a front end wall (41) which confronts said front passageway (22), and a rear end wall (42) which is disposed opposite to said front end wall (41) and which extends outwardly of said rearward opening (232) to be manually operable, characterized by: a carrier (5) having a tail portion (517) which extends from said front end wall (41) along the axis (X), a head portion (523) which is disposed opposite to said tail portion (517) in said rear passageway along the axis (X), and an intermediate surrounding portion which is interposed between said tail and head portions (517,523) and which surrounds the axis (X), said intermediate surrounding portion having a pushing region (516) and a retained region (527) which are proximate to said tail and head portions (517,523), respectively; and a hollow deformable sealing member (6) having a head end wall (613) which has a periphery and which confronts said surrounding shoulder (24), an upper sealing end (615) which is integrally formed with said periphery of said head end wall (613) and which is in fluid-tight and slidable engagement with said rear larger-diameter portion, and a deformable surrounding wall (612) which extends from said upper sealing end (615) rearwardly and which terminates at a surrounding trailing end (616) that is configured to drag on said rear larger-diameter portion, said deformable surrounding wall (612) having an outer surrounding wall surface (622) which is spaced apart from said rear larger-diameter portion in radial directions when said syringe is in a position of use, thereby vesting said deformable surrounding wall (612) with an increased radial flexibility, and an inner surrounding wall surface (617) which is opposite to said outer surrounding wall surface (622) in radial directions, said inner surrounding wall surface (617) having a yielding segment (610) which is engaged with and which is depressed by said pushing region (516) radially when safd carrier (5) is moved in a longitudinal direction relative to said deformable surrounding wall (612) so as to bring said head end wall (613) to abut against and to be retained at said surrounding shoulder (24), thereby displacing said syringe from the position of use to a disposal position, and a retaining segment (618) which is in a first frictional engagement with said retained region (527) by virtue of a first frictional force so as to confine, in cooperation with said yielding segment (610) and said pushing region (516), a fluid-tight surrounding area, and which is configured such that the first frictional force is diminished so as to facilitate release of said retained region (527) from said retaining segment (618) when said yielding segment (610) is depressed by said pushing region (516), thereby disrupting the fluid-tightness of said surrounding area and rendering the syringe unreusable. 2. The single-use syringe as claimed in claim 1, wherein said surrounding trailing end (616) of said deformable surrounding wall (612) is in fluid- tight and slidable engagement with said rear larger-diameter portion, said outer surrounding wall surface (622) of said deformable surrounding wall (612) being configured to cooperate with said upper sealing end (615) to define an annular compressible chamber (621) between said upper sealing end (615) and said surrounding trailing end (616) such that, subsequent to abutment of said head end wall (613) against said surrounding shoulder (24), said yielding segment (610) is depressed by said pushing region (516) radially and outwardly to result in deformation of said deformable surrounding wall (612) which moves said inner surrounding wall surface (617) radially and towards said rear larger-diameter portion so as to diminish the first frictional force, thereby disrupting the fluid- tightness of said surrounding area, and facilitating disengagement of said carrier (5) from said deformable sealing member (6) when said carrier (5) is moved rearwards by said plunger (4) towards said rearward opening (232). 3. The single-use syringe as claimed in claim 2, wherein said intermediate surrounding portion (51,52) of said carrier (5) comprises: a tubular pushing segment (51) serving as said pushing region (516), said pushing segment (51) being coupled and formed integrally with said tail portion (517), and terminating at an opened end (513), said pushing segment (51) having an inner surrounding engaging region (514) which extends in the longitudinal direction to be communicated with said opened end (513), and which surrounds the axis (X) to define a cavity (511), and a tubular retained segment (52) serving as said retained region (527), said retained segment (52) having an outer surrounding retained wall (521) which extends from said head portion (523) in the longitudinal direction to terminate at an outer engaging end (524) and which is configured to be insertable into said cavity (511) to bring said outer surrounding retained wall (521) into a second frictional engagement with said inner surrounding engaging region (514) such that, subsequent to the disruption of the fluid- tightness of said surrounding area, said head portion (523) is blocked by said surrounding shoulder (24) from moving further so as to permit said outer surrounding retaining wall (521) to be in the second frictional engagement with said inner surrounding engaging region (514), thereby facilitating disengagement of said carrier (5) from said deformable sealing member (6). 4. The single-use syringe as claimed in claim 3, wherein said tubular pushing segment (51) has a vent hole (515) in fluid communication with said cavity (511); 5. The single-use syringe as claimed in claim 2, wherein said deformable surrounding wall (612) is configured such that when said inner surrounding wall surface (617) is moved radially and towards said rear larger-diameter portion, said deformable surrounding wall (612) squeezes air out of said annular compressible chamber (621) so as to permit said outer surrounding wall surface (622) to abut against said rear larger- diameter portion. 6. The single-use syringe as claimed in claim 1, comprising: a passageway interrupting member (623,63,64,65,67,68,69) which is disposed to be engaged with one of said head portion (523) of said carrier (5) and said head end wall (613) of said deformable sealing member (6), and which is configured such that once the fluid-tightness of said surrounding area is disrupted, said passageway interrupting member (623,63,64,65,67,68,69) is forced by a corresponding one of the said head portion (523) and said head end wall (613) to plug said front passageway (22). 7. The single-use syringe as claimed in claim 6, wherein said passageway interrupting member (623,63,64,67,68) has frictional ribs (625,626,631,641,675,685) disposed thereon for frictional engagement with said smaller-diameter portion. 8. The single-use syringe as claimed in claim 6, wherein said passageway interrupting member (65,69) has two prongs (651) which acquire a biasing force to reinforce plugging-in engagement of said passageway interrupting member (65,69) with said front smaller-diameter portion. 9. The single-use syringe as claimed in claim 6, wherein said passageway interrupting member (623) is integrally formed with the corresponding one of said head portion (523) and said head end wall (613) such that once the fluid-tightness of said surrounding area is disrupted, the diminution of the first frictional force enables disengagement of said retained region (527) from said retaining segment (618), thereby permitting disengagement of said deformable sealing member (6) from said carrier (5) when said carrier (5) is moved rearwards by said plunger (4) toward said rearward opening (232). 10.The single-use syringe as claimed in claim 6, wherein said head portion (523) of said carrier (5) has an inner peripheral grip wall (55) which defines an insert bore (56) extending along the axis (X) through said intermediate surrounding portion and which is of a dimension such that said inner peripheral grip wall (55) acquires a radial flexibility, thereby yielding radially and towards the axis (X) to the first frictional force so as to facilitate disruption of the fluid-tightness of said surrounding area. 11. The single-use syringe as claimed in claim 10, wherein said passageway interrupting member (67,68,69) has a gripped end (674) which is retained in said insert bore (56) when said inner peripheral grip wall (55) yields to the first frictional force, and a plug head (677) which is opposite to said gripped end (674) in the longitudinal direction, and which extends forwardly and outwardly of said head end wall (613) of said deformable sealing member (6) such that once the fluid-tightness of said surrounding area is disrupted, the diminution of the first frictional force upon the first frictional engagement lessens the degree of yielding towards the axis (X) so as to permit said inner peripheral grip wall (55) to release said gripped end (674), thereby permitting said plug head (677) to be retained in said front passageway (22) when said carrier (5) is moved in the longitudinal direction relative to said deformable surrounding wall (612). 12. The single-use syringe as claimed in claim 11, wherein said intermediate surrounding portion has a pulling region (57) which is disposed rearwardly of said pushing region (516), said inner surrounding wall surface of said deformable surrounding wall (612) having a pulled segment (62) which is disposed between said yielding segment (610) and said retaining segment (618) and which is configured such that said pulling region (57) is displaced to abut against said pulled segment (62) subsequent to the disruption of the fluid-tightness of said surrounding area, and such that said pulling region (57) is forced by a rearward movement of said carrier (5) to depress said pulled segment (62) to move towards said rearward opening (232), thereby permitting movement of said deformable sealing member (6) with said carrier (5) so as to bring said plug head (677) to disengage from said head end wall (613) of said deformable sealing member (6) when said plug head (677) is retained in said front passageway (22). 13. The single-use syringe as claimed in claim 1, wherein said carrier (5) comprises a projection member (53) which is integrally formed with said head portion (523) and which extends through said head end wall (613) of said deformable sealing member (6) such that when said carrier (5) is moved rearwards, said projection member (53) is disengaged from said head end wall (613) of said deformable sealing member (6). The invention relates to a single-use syringe comprises a barrel (2) having front and rear passageways (22,21) and a shoulder (24) disposed therebetween, a plunger (4) movable in the rear passageway (21), a carrier (5) having a tail portion (517) extending from a front end wall (41) of the plunger (4), and pushing and retained regions (516, 527) formed forwardly of the tail portion (517), and a deformable sealing member (6) in fluid- tight and slidable engagement with the barrel (2), the sealing member (6) includes an inner surrounding wall surface (617) with a yielding segment (610) engaging the pushing region (516), and a retaining segment (613) in frictional engagement with the retained region (527) by a frictional force so as to confine a fluid-tight surrounding area. The frictional force is diminished when the yielding segment (610) is depressed by the pushing region (516) so as facilitate release of the retained region (527) from the retaining segment (613), thereby disrupting the fluid-tightness of the surrounding area and rendering the syringe unreusable.

Full Text

This invention relates to a single-use syringe, more
particularly to a single-use syringe, in which fluid-tightness
of a barrel is disrupted when the syringe is displaced to a
disposal position so as to render the syringe unreusable.
Referring to Figs . 1 and 2, a conventional single-use syringe
is shown to include a barrel 11 which has an axially extending
surrounding wall 113 defining front and rear passageways 112, 111,
and a surrounding shoulder 114 disposed between the front and
rear passageways 112 , 111, a needle assembly 12 which is sleeved
on a front opened end of the surrounding wall 113, a plunger
13 which is disposed to be movable in and along the rear passageway
111 and which has a taperedhead 131 formed ona front end thereof,
a deformable sealing member 14 which is retainingly sleeved
on the tapered head 131, which is in fluid-tight and slidable
engagement with the surrounding wall 113 at the rear passageway
111, and which has an axially extending vent hole 132
communicated with the ambient air, and a plug 15 which is
detachably connected to the deformable sealing member 14 and
which closes the vent hole 132. An inner surface of the
surrounding wall 113 has a retaining ring 115 formed adjacent
to the shoulder 114. The plug 15 has an anchoring portion 151
projecting forwardly and outwardly of the deformable sealing
member 14 such that, subsequent to completion of injection,
the deformable sealing member 14 is brought to abut against
the shoulder 114 and the anchoring portion 151 is engaged with
the retaining ring 115 to thereby permit disengagement of the
plug 15 from the deformable sealing member 14 when the plunger
13 is pulled rearwardly, and to thereby disrupt the
fluid-tightness of the vent hole 132 for rendering the syringe
unreusable. However, when the anchoring portion 151 is forced
to be engaged with the retaining ring 115, the frictional force
between the plug 15 and the deformable sealing member 14 is
increased, which may be greater than the force of engagement
between the anchoring portion 151 and the retaining ring 115,
thereby adversely affecting separation of the plug 15 from the
deformable sealing member 14. Moreover, formation of the
retaining ring 115 on the inner surface of the barrel 11 is
inconvenient during manufacture.
An object of the present invention is to provide a single-use
syringe which has friction diminishing means to facilitate
disruption of fluid-tightness of a surrounding area in a barrel
when the syringe is displaced to a disposal position so as to
render the syringe unreusable.
According to this invention, the single-use syringe
includes a barrel having an inner surrounding barrel surface
which surrounds an axis in a longitudinal direction, and which
includes a rear larger-diameter portion that defines a rear
passageway therein, a front smaller-diameter portion that
defines a front passageway therein to be in fluid communication
with a needle assembly and that is opposite to the rear
larger-diameter portion in the longitudinal direction, and a
surrounding shoulder that is disposed between the rear
larger-diameter portion and the front smaller-diameter portion.
The rear passageway terminates at a rearward opening.
A plunger is disposed to be movable in the rear passageway
along the larger-diameter portion. The plunger has a front end
wall which confronts the front passageway, and a rear end wall
which is disposed opposite to the front end wall and which extends
outwardly of the rearward opening to be manually operable.
A carrier includes a tail portion which extends from the
front end wall along the axis, a head portion which is disposed
opposite to the tail portion in the rear passageway along the
axis, and an intermediate surrounding portion which is
interposed between the tail and head portions and which
surrounds the axis. The intermediate surrounding portion has
a pushing region and a retained region which are proximate to
the tail and head portions, respectively.
A hollow deformable sealing member includes a head end wall
which has a periphery and which confronts the surrounding
shoulder, an upper sealing end which is integrally formed with
the periphery of the head end wall and which is in fluid-tight
and slidable engagement with the rear larger-diameter portion,
and a deformable surrounding wall which extends from the upper
sealing end rearwardly and which terminates at a surrounding
trailing end that is configured to drag on the rear
larger-diameter portion. The deformable surrounding wall has
an outer surrounding wall surface which is spaced apart from
the rear larger-diameter portion in radial directions when the
syringe is in a position of use, thereby vesting the deformable
surrounding wall with an increased radial flexibility, and an
inner surrounding wall surface which is opposite to the outer
surrounding wall surface in radial directions. The inner
surrounding wall surface has a yielding segment which is engaged
with and which is depressed by the pushing region radially when
the carrier is moved in a longitudinal direction relative to
the deformable surrounding wall so as to bring the head end
wall to abut against and to be retained at the surrounding
shoulder, thereby displacing the syringe from the position of
use to a disposal position, and a retaining segment which is
in a f rictional engagement with the retained region by virtue
of a frictional force so as to confine, in cooperation with
the yielding segment and the pushing region, a fluid-tight
surrounding area, and which is configured such that the
frictional force is diminished so as to facilitate release of
the retained region from the retaining segment when the yielding
segment is depressed by the pushing region, thereby disrupting
the fluid-tightness of the surrounding area and rendering the
syringe unreusable.
Other features and advantages of the present invention will
become apparent in the following detailed description of the
preferred embodiments of the invention, with reference to the
accompanying drawings, in which:
Fig. 1 is a sectional view of a conventional single-use
syringe;
Fig. 2 is a sectional view of the conventional single-use
syringe of Fig. 1 after use;
Fig. 3 is an exploded sectional view of the first preferred
embodiment of a single-use syringe according to this invention;
Fig. 4 is a sectional view of the first preferred embodiment
during an injection stroke;
Figs . 5 is a sectional viewof the first preferred embodiment,
showing the state of completion of the injection stroke;
Figs. 6 to 8 are sectional views of the first preferred
embodiment, showing an operation of disrupting fluid-tightness
of the syringe;
Fig. 9 is a sectional view of the second preferred embodiment
of a single-use syringe according to this invention;
Fig. 10 is a sectional view of a modified form of the second
preferred embodiment shown in Fig. 9;
Fig. 11 is a sectional view of the third preferred embodiment
of a single-use syringe according to this invention;
Figs. 12 and 13 are sectional views of the third preferred
embodiment, showing an operation of disrupting fluid-tightness
of the syringe;
Fig. 14 is a sectional view of a modified form of the third
preferred embodiment shown in Fig. 11;
Fig. 15 is a sectional viewof the fourthpref erred embodiment
of a single-use syringe according to this invention;
Fig. 16 is a sectional viewof the fourthpref erred embodiment
after disruption of fluid-tightness of the syringe;
Fig. 17 is a sectional view of a modified form of the fourth
preferred embodiment shown in Fig. 15;
Fig. 18 is a sectional view of another modified form of
the fourth preferred embodiment shown in Fig. 15;
Fig. 19 is a sectional view of the fifth preferred embodiment
of a single-use syringe according to this invention;
Figs. 20 and 21 are sectional views of the fifth preferred
embodiment, showing an operation of disrupting fluid-tightness
of the syringe;
Fig. 22 is a sectional view of the sixth preferred embodiment
of a single-use syringe according to this invention;
Fig. 23 is a sectional view of a modified form of the sixth
preferred embodiment shown in Fig. 22;
Fig. 24 is a sectional view of the seventh preferred
embodiment of a single-use syringe according to this invention;
Fig. 25 is a sectional view of a modified form of the seventh
preferred embodiment shown in Fig. 24;
Fig. 26 is a sectional view of another modified form of
the seventh preferred embodiment shown in Fig. 24;
Fig. 27 is an exploded sectional viewof the eighth preferred
embodiment of a single-use syringe according to this invention;
Fig. 28 is an exploded sectional view of the ninth preferred
embodiment of a single-use syringe according to this invention;
Fig. 2 9 is a fragmentary sectional view of the tenth preferred
embodiment of a single-use syringe according to this invention;
Fig. 3 0 is a sectional view of the tenth preferred embodiment
after disruption of the fluid-tightness of the syringe;
Fig. 31 is a sectional view of a modified form of the tenth
preferred embodiment shown in Fig. 29;
Fig. 32 is a fragmentary sectional view of the eleventh
preferred embodiment of a single-use syringe according to this
invention;
Fig. 33 is a sectional view of the eleventh preferred
embodiment after disruption of the fluid-tightness of the
syringe;
Fig. 34 is a sectional view of a modified form of the eleventh
preferred embodiment shown in Fig. 32;
Fig. 35 is a sectional view of another modified form of
the eleventh preferred embodiment shown in Fig. 32;
Fig. 3 6 is a fragmentary sectional view of the twelfth
preferred embodiment of a single-use syringe according to this
invention;
Fig. 3 7 is a sectional view of the twelfth preferred
embodiment after disruption of the fluid-tightness of the
syringe;
Fig. 38 is a sectional view of a modified form of the twelfth
preferred embodiment shown in Fig. 36; and
Fig. 39 is a sectional view of another modified form of
the twelfth preferred embodiment shown in Fig. 36.
Before the present invention is described in greater detail,
it should be noted that same reference numerals have been used
to denote like elements throughout the specification.
Referring to Figs. 3 and 4, the first preferred embodiment
of a single-use syringe according to the present invention is
shown to be used with a needle assembly 3 . The needle assembly
3 includes a needle hub 31 and a needle cannula 32 . The syringe
comprises a barrel 2, a plunger 4, a carrier 5, and a hollow
deformable sealing member 6.
The barrel 2 has an inner surrounding barrel surface 23
which surrounds an axis (X) in a longitudinal direction, and
which includes a rear larger-diameter portion that defines a
rear passageway 21 therein, a front smaller-diameter portion
that defines a front passageway 22 therein to be in fluid
communication with the needle assembly 3 in a known manner,
and that is opposite to the rear larger-diameter portion in
the longitudinal direction, and a surrounding shoulder 24 that
is disposed between the rear larger-diameter portion and the
front smaller-diameter portion. The front and rear passageways
22,21 respectively terminate at forward and rearward openings
231,232.
The plunger 4 is disposed to be movable in the rear passageway
21 along the larger-diameter portion. The plunger 4 has a front
end wall 41 which confronts the front passageway 22, and a rear
end wall 42 which is disposed opposite to the front end wall
41 along the longitudinal direction and which extends outwardly
of the rearward opening 232 to be manually operable.
The carrier 5 includes a tail portion 517 which extends
from the front end wall 41 along the axis (X) , a head portion
523 which is disposed in the rear passageway 21 opposite to
the tail portion 517 and along the axis (X) , and an intermediate
surrounding portion which is interposed between the tail and
head portions 517,523 and which surrounds the axis (X). The
intermediate surrounding portion includes a tubular pushing
segment 51 and a tubular retained segment 52 . The pushing segment
51 is coupled and formed integrally with the tail portion 517,
and terminates at an opened end 513. The pushing segment 51
has an inner surrounding engaging region 514 which extends in
the longitudinal direction to be communicated with the opened
end 513 and which defines a cavity 511, and a pushing region
516 which is disposed radially and outwardly of the inner
surrounding engaging region 514. Preferably, the pushing
segment 51 is converged from the pushing region 516 to the opened
end 513. A vent hole 515 is formed in the pushing segment 51,
and extends along the axis (X) to be in fluid communication
with the cavity 511. The retained segment 52 has an outer
surrounding retained wall 521 which extends from the head
portion 523 in the longitudinal direction to terminate at an
outer engaging end 524 and which is insertable into the cavity
511. The outer surrounding retained wall 521 has two annular
grooves 525,526, and a projecting retained region 527 formed
between the annular grooves 525,526. In a position of use, as
shown in Fig. 4, the outer engaging end 524 is frictionally
engaged with the inner surrounding engaging region 514 such
that the annular grooves 525,526 and the retained region 527
are projected outwardly of the pushing segment 51.
The deformable sealing member 6 includes a head end wall
613 which has a periphery and which confronts the surrounding
shoulder 24, an upper sealing end 615 which is integrally formed
with the periphery of the head end wall 613 and which is in
fluid-tight and slidable engagement with the rear
larger-diameter portion, and a deformable surrounding wall 612
which extends from the upper sealing end 615 rearwardly and
which terminates at a surrounding trailing end 616 that is
configured to drag on and to be in fluid-tight engagement with
the rear larger-diameter portion. The deformable surrounding
wall 612 has an outer surrounding wall surface 622 which is
spaced apart from the rear larger-diameter portion in radial
directions when the syringe is in the position of use so as
to cooperative with the upper sealing end 615 and the surrounding
trailing end 616 to define an annular compressible chamber 621
thereamong, thereby vesting the deformable surrounding wall
612 with an increased radial flexibility. The deformable
surrounding wall 612 further has an inner surrounding wall
surface 617 opposite to the outer surrounding wall surface 622
in radial directions. The inner surrounding wall surface 617
has a yielding segment 610 which is engaged with and which is
depressed by the pushing region 516 radially when the carrier
5 is moved in a longitudinal direction relative to the deformable
surrounding wall 612 so as to bring the head end wall 613 to
abut against and to be retained at the surrounding shoulder
24, thereby displacing the syringe from the position of use
to a disposal position, and a retaining segment 618 which is
in a first frictional engagement with the retained region 527
by virtue of a first frictional force so as to confine, in
cooperationwith the yielding segment 610 and the pushing region
516, a fluid-tight surrounding area. Thus, referring to Figs.
5 to 7, subsequent to the abutment of the head end wall 613
against the surrounding shoulder 24, the yielding segment 610
is depressed by the pushing region 516 radially and outwardly

to result in deformation of the deformable surrounding wall
612, which moves the inner surrounding wall surface 617 radially
and towards the rear larger-diameter portion so as to diminish
the first frictional force, thereby disrupting the
fluid-tightness of the surrounding area and rendering the
syringe unreusable. Subsequent to the disruption of the
fluid-tightness of the surrounding area, the head portion 523
is blocked by the surrounding shoulder 24 from moving further
so as to permit movement of the pushing segment 51 relative
to the retained segment 52 such that the outer surrounding
retained wall 521 is brought into a second f rictional engagement
with the inner surrounding engaging region 514 . Meanwhile, the
deformable surrounding wall 612 is deformed to squeeze the air
out of the annular compressible chamber 621 so that the outer
surrounding wall surface 622 is tightly attached to the rear
larger-diameter portion. Subsequently, referring to Fig. 8,
when the carrier 5 is moved rearwards by the plunger 4 towards
the rearward opening 232, the carrier 5 is disengaged from the
deformable sealing member 6.
Referring to Fig. 9, the second preferred embodiment of
a single-use syringe according to this invention is shown to
be similar to the previous embodiment in construction. The
syringe of this embodiment further includes a passageway
interrupting member 62 3 which is integrally formed with the
head end wall 613 of the deformable sealing member 6 such that
once the fluid-tightness of the surrounding area is disrupted,
the passageway interrupting member 62 3 is forced by the head

end wall 613 to extend into the front passageway 22. The
passageway interrupt ing member 623 has a plurality of f rictional
ribs 625 disposed thereon, and a diameter larger than that of
the front passageway 22 so as to be in a frictional engagement
with the front smaller-diameter portion. Thus, the diminution
of the first frictional force enables disengagement of the
retained region 527 from the retaining segment 618, thereby
facilitating disengagement of the deformable sealing member
6 from the carrier 5 when the carrier 5 is moved rearwardly
by the plunger 4 toward the rearward opening 232 . Alternatively,
referring to Fig. 10, the passageway interrupting member 62 3
has a longer length so as to plug the entire front passageway
22 for minimizing the amount of medication remaining in the
barrel 2.
Referring to Figs. 11 to 13, the third preferred embodiment
of a single-use syringe according to this invention is shown
to be similar to the first preferred embodiment in construction.
The carrier 5 of this embodiment further includes a projection
member 53 which is integrally formed with the head portion 523
and which extends forwardly through a slit 619 in the head end
wall 613 of the deformable sealing member 6. The projection
member 53 has a diameter slightly smaller than that of the front
passageway 22, and is moved with the head portion 523 by the
plunger 4 to be inserted into the front passageway 22 in an
injection stroke for reducing the amount of medication left
in the barrel 2. When the carrier 5 is moved rearwardly, the
projection member 53 is moved to disengage from the head end

wall 613 of the deformable sealing member 6 so as to completely-
disrupt the fluid-tightness of the surrounding area. In a
modified form of the embodiment, as shown in Fig. 14, the
projection member 53 has a longer length so as to plug the entire
front passageway 22 for minimizing the amount of medication
remaining in the barrel 2.
Referring to Figs . 15 and 16, the fourth preferred embodiment
of a single-use syringe according to this invention is shown
to be similar to the first preferred embodiment in construction.
The syringe of this embodiment further includes a passageway
interrupting member 63 which is integrally formed with the head
portion 523 of the carrier 5 and which projects outwardly of
the head end wall 613 of the deformable sealing member 6 through
a slit 619 in the head end wall 613 . The passageway interrupting
member 63 has a plurality of frictional ribs 631 formed thereon,
and a diameter larger than that of the front passageway 22 so
as to be; in frictional engagement with the front
smaller-diameter portion and so as to enable the head portion
523 to abut against the head end wall 613 . When the tail portion
517 of the carrier 5 is moved rearwardly by the plunger 4 toward
the rearward opening 232, the pushing segment 51 is disengaged
from the retained segment 52 to completely disrupt the
fluid-tightness of the surrounding area for rendering the
syringe unreusable.
Referring to Fig. 17, a modified form of the syringe of
the fourth preferred embodiment is shown to comprise a
passageway interrupting member 64 which has a length sufficient

to fully plug the front passageway 22. The passageway
interrupting member 64 has a rear end segment 642 formed with
a plurality of frictional ribs 641, and a front end segment
643 with a diameter smaller than that of the front passageway
22. Referring to Fig. 18, another modified form of the syringe
of the fourth preferred embodiment is shown to comprise a
passageway interrupting member 65 which has two prongs 651 that
project outwardly of the forward opening 231 to acquire a biasing
force so as to reinforce plugging-in engagement of the
passageway interrupting member 65 with the front
smaller-diameter portion.
Referring to Figs. 19 to 21, the fifth preferred embodiment
of a single-use syringe according to this invention is shown
to be similar to the first preferred embodiment in construction.
In this embodiment, the carrier 5 and the plunger 4 are an
integrally formed structure. The carrier 5 includes a tail
portion 517 with a plurality of rib plates 518, and an
intermediate surrounding portion extending forwardly from the
tail portion 517 to terminate at a head portion 523. The
intermediate surrounding portion has a pushing region 516 to
depress the yielding segment 610 of the deformable sealing
member 6, and a retained region 52 7 in frictional engagement
with the retaining segment 618 of the deformable sealing member
6. The carrier 5 has an insert bore 56 extending from the head
portion 523 along the axis (X) to acquire a radial flexibility
so as to facilitate movement of the carrier 5 relative to the
deformable sealing member 6 after abutment of the head end wall

613 against the surrounding shoulder 24.
Referring to Figs . 22 and 23 , the sixth preferred embodiment
of a single-use syringe according to this invention is shown
to be similar to the fifth preferred embodiment in construction.
The syringe of this embodiment further includes a passageway
interrupting member 623 which is integrally formed with the
head end wall 613 of the deformable sealing member 6, and which
has a plurality of frictional ribs 625 disposed thereon and
having a diameter larger than that of the front passageway 22
so as to be in a frictional engagement with the front
smaller-diameter portion, thereby facilitating disengagement
of the deformable sealing member 6 from the carrier 5 when the
carrier 5 is moved rearwardly by the plunger 4 . Alternatively,
referring to Fig. 23, the passageway interrupting member 623
may have a longer length so as to plug the entire front passageway
22 for minimizing the amount of medication remaining in the
barrel 2.
Referring to Figs . 24 to 26, the seventh preferred embodiment
of a single-use syringe according to this invention is shown
to be similar to the fifth preferred embodiment in construction.
In this embodiment, the head portion 523 of the carrier 5 has
an inner peripheral grip wall 55 which defines an insert bore
56 extending along the axis (X) through the intermediate
surrounding portion such that the inner peripheral grip wall
55 acquires a radial flexibility, thereby yielding radially
and towards the axis (X) to the first frictional force of the
first frictional engagement between the retaining segment 618

and the retained region 527. The syringe further comprises a
passageway interrupting member 67 . The passageway interrupting
member 67 has a gripped end 674 which is retained in the insert
bore 56 when the inner peripheral grip wall 55 yields to the
first frictional force and which has a plurality of frictional
ribs 673 formed thereon, a plug head 677 which is opposite to
the gripped end 674 in the longitudinal direction and which
extends f orwardly and outwardly of the head end wall 613 through
a slit 619, and an abutment ring 672 which is disposed between
the gripped end 674 and the plug head 677. The plug head 677
has a plurality of frictional ribs 675 formed thereon. Therefore,
once the fluid-tightness of the surrounding area is disrupted,
the plug head 677 plugs the front passageway 22 with the abutment
ring 672 abutting against the head end wall 613 . Referring to
Fig. 25, in a modified form of the seventh preferred embodiment,
the passageway interrupting member 68 has a length sufficient
to fully plug the front passageway 22 for minimizing the amount
of medication remaining in the barrel 2 . The plug head 686 of
the passageway interrupting member 68 has a rear segment formed
with a plurality of frictional ribs 685, and a front end segment
687 with a diameter smaller than that of the front passageway
22. Alternatively, in another modified form of the syringe of
the seventh preferred embodiment shown in Fig. 26, the
passageway interrupting member 69 has two prongs 695 that
project outwardly of the forward opening 231 to acquire a biasing
force to reinforce plugging-in engagement of the passageway
interrupt ing member 69 with the front smaller-diameterportion.

Referring to Fig. 27, the eighth preferred embodiment of
a single-use syringe according to this invention is shown to
be similar to the seventh preferred embodiment in construction.
In this embodiment, each of the passageway interrupting members
67,68,69 that are selectively insertable into the insert bore
56 is not formed with an abutment ring so as to simplify the
structure thereof.
Referring to Fig. 28, the ninth preferred embodiment of
a single-use syringe according to this invention is shown to
be similar to the eighth preferred embodiment in construction.
As shown, the pushing region 516 of the carrier 5 has a relatively
smooth surface. Although the yielding segment 610 of the
deformable sealing member 6 is depressed by the pushing region
516 so that the deformable surrounding wall 612 is partly
attached to the rear larger-diameter portion of the barrel 2,
thedeformable seal ing member 6 maybe retained by the passageway
interrupting member 67,68,69 after the carrier 5 is moved
rearwardly.
Referring to Figs . 29 and 3D, the tenth preferred embodiment
of a single-use syringe according to this invention is shown
to be similar to the sixth preferred embodiment in construction.
In this embodiment, the carrier 5 has two annular teeth formed
on the intermediate surrounding portion to respectively serve
as the pushing region 516 and the retained region 527. The
deformable surrounding wall 612 has two annular grooves formed
in the inner surrounding wall surface to respectively serve
as the yielding segment 610 and the retaining segment 618, and

a moving space 66 formed forwardly of the annular grooves.
Therefore, subsequent to the abutment of the head end wall 613
against the surrounding shoulder 24 , the carrier 5 can be forced
to move forwardly relative to the deformable sealing member
6 to insert, into the moving space 66 so as to diminish the first
frictional force upon the first frictional engagement, of the
retained region 527 with the retaining segment 618, thereby
disrupting the fluid-tightness of the surrounding area for
rendering the syringe unreusable. Alternatively, the
passageway interrupting member 623 may have a length sufficient
to plug the entire front passageway 22 for minimizing the; amount
of medication remaining in the barrel 2, as shown in Fig. 31.
Referring to Figs. 32 and 33, the eleventh preferred
embodiment of a single-use syringe according to this invention
is shown to be similar to the tenth preferred embodiment in
construction. In this embodiment, the passageway interrupting
member 67 has a gripped end 674 which is retained in the insert
bore 56 when the inner peripheral grip wall 55 yields to the
first frictional force of the first frictional engagement
between the retaining segment 618 and the retained region 527
and which has a plurality of frictional ribs 673 formed thereon,
and a plug head 677 which extends forwardly and outwardly of
the head end wall 613 through a slit 619 in the head end wall
613, and which has a plurality of frictional ribs 675 formed
thereon. The diminution of the first frictional force upon the
first frictional engagement of the retained region 52 7 with
the retaining segment 618 lessens the degree of yielding towards

the axis (X) so as to permit the inner peripheral grip wall
55 to release the gripped end 674, thereby permitting the plug
head 677 to be retained in the front passageway 22 when the
carrier 5 is moved in the longitudinal direction relative to
the deformable surrounding wall 612.
Furthermore, the intermediate surrounding portion of the
carrier 5 further has a pulling region 57 which is disposed
rearwardly of the pushing region 516. The inner surrounding
wall surface of the deformable surrounding wall 612 has a pulled
segment 62 which is disposed between the yielding segment 610
and the retaining segment 618. Therefore, subsequent to the
movement of the carrier 5 into the moving space 66 to disrupt
the fluid-tightness of the surrounding area, the pulling region
57 is displaced to abut against the pulled segment 62 such that
the pulling region 57 is forced by a rearward movement of the
carrier 5 to depress the pulled segment 62 to move towards the
rearward opening 232, thereby permitting movement of the
deformable sealing member 6 with the carrier 5 so as to bring
the plug head 677 to disengage from the head end wall 613 of
the deformable sealing member 6 when the plug head 677 is retained
in the front passageway 22.
In the modified form of the eleventh preferred embodiment
as shown in Fig. 34, the passageway interrupting member 68 has
a length sufficient to plug the entire front passageway 22 for
minimizing the amount of medication remaining in the barrel
2. The plug head 686 of the passageway interrupting member 68
has a rear segment formed with a plurality of frictional ribs

685, and a front end segment 687 with a diameter smaller than
that of the front passageway 22 . Referring to Fig. 35, in another
modified form of the syringe of the eleventh preferred
embodiment, the passageway interrupting member 69 which has
two prongs 695 that project outwardly of the forward opening
231 to acquire a biasing force to reinforce plugging-in
engagement of the passageway interrupting member 69 with the
front smaller-diameter portion.
Referring to Figs. 36 and 37, the twelfth preferred
embodiment of a single-use syringe according to this invention
is shown to be similar to the eleventh preferred embodiment
in construction. In this embodiment, the intermediate
surrounding portion of the carrier 5 includes a tubular pushing
segment 51 with the pushing region 516, and a tubular retained
segment 52 with the retained region 527. The pushing segment
51has an insert bore 56 extending along the axis (X) . The retained
segment 52 has a grip portion 52 8 which is retained in the insert
bore 56, and which has a plurality of frictional ribs 529 formed
thereon. The passageway interrupting member 67 is integrally
formed with the head portion 523, extends forwardly and
outwardly of the head end wall 613 through the slit 619, and
has a plurality of frictional ribs 675 formed thereon. Therefore,
subsequent to the disruption of the fluid-tightness of the
surrounding area, the head port ion 523 is brought to abut cigainst
the head end wall 613 so as to permit the passageway interrupting
member 67 to plug the front passageway 22.
In the modified form of the twelfth preferred embodiment

as shown in Fig. 38, the passageway interrupting member 68 has
a length sufficient to plug the entire front passageway 22 for
minimizing the amount of medication remaining in the barrel
2 . The passageway interrupting member 68 has a rear segment
formed with a plurality of frictional ribs 685, and a front
end segment 687 with a diameter smaller than that of the front
passageway 22. Referring to Fig. 39, in another modified form
of the syringe of the twelfth preferred embodiment, the
passageway interrupting member 69 has two prongs 695 that
project outwardly of the forward opening 231 to acquire a biasing
force to reinforce plugging-in engagement of the passageway
interrupt ing member 69 with the front smaller-diameter portion.
As illustrated, in the syringe of this invention, during
displacement of the syringe from the position of use to the
disposal position, the first frictional force, by which the
retaining segment 618 of the deformable sealing member 6 is
in frictional engagement with the retained region 52 7 of the
carrier 5, is diminished when the yielding segment 610 is
depressed by the pushing region 516, thereby facilitating
release of the retained region 527 from the retaining segment
618 to ensure disruption of the fluid-tightness of the
surrounding area for rendering the syringe unreusable . Moreover,
the passageway interrupting member 623,63,64,65,67,68,69 is
provided to plug the front passageway 22 of the barrel 2 even
when the plunger 4 is moved rearwardly, thereby preventing the
syringe from being reused. Also, the passageway interrupting
member 623,63,64,65,67,68,69 can be coupled with one of the

head portion 523 of the carrier 5 and the head end wall 613
of the deformable sealing member 6. Therefore, the barrel 2,
the carrier 5, the plunger 4, and the passageway interrupting
member can be fabricated conveniently without the need to modify
the barrel 2.
We Claim:
1. A single-use syringe adapted to be used with a needle assembly (3),
comprising:
a barrel (2) having an inner surrounding barrel surface (23) which
surrounds an axis (X) in a longitudinal direction, and which comprises a rear
larger-diameter portion that defines a rear passageway (21) therein, a front
smaller-diameter portion that defines a front passageway (22) therein to be
in fluid communication with the needle assembly (3) and that is opposite to
said rear larger-diameter portion (21) in the longitudinal direction, and a
surrounding shoulder (24) that is disposed between said rear larger-diameter
portion and said front smaller-diameter portion, said rear passageway (21)
terminating at a rearward opening (232); and
a plunger (4) which is disposed to be movable in said rear passageway
(21) along said larger-diameter portion, said plunger (4) having a front end
wall (41) which confronts said front passageway (22), and a rear end wall
(42) which is disposed opposite to said front end wall (41) and which extends
outwardly of said rearward opening (232) to be manually operable,
characterized by:
a carrier (5) having a tail portion (517) which extends from said front end
wall (41) along the axis (X), a head portion (523) which is disposed opposite
to said tail portion (517) in said rear passageway along the axis (X), and an
intermediate surrounding portion which is interposed between said tail and
head portions (517,523) and which surrounds the axis (X), said intermediate
surrounding portion having a pushing region (516) and a retained region
(527) which are proximate to said tail and head portions (517,523),
respectively; and
a hollow deformable sealing member (6) having a head end wall (613)
which has a periphery and which confronts said surrounding shoulder (24),
an upper sealing end (615) which is integrally formed with said periphery of
said head end wall (613) and which is in fluid-tight and slidable engagement
with said rear larger-diameter portion, and a deformable surrounding wall
(612) which extends from said upper sealing end (615) rearwardly and which
terminates at a surrounding trailing end (616) that is configured to drag on
said rear larger-diameter portion, said deformable surrounding wall (612)
having an outer surrounding wall surface (622) which is spaced apart from
said rear larger-diameter portion in radial directions when said syringe is in a
position of use, thereby vesting said deformable surrounding wall (612) with
an increased radial flexibility, and an inner surrounding wall surface (617)
which is opposite to said outer surrounding wall surface (622) in radial
directions, said inner surrounding wall surface (617) having a yielding
segment (610) which is engaged with and which is depressed by said pushing
region (516) radially when safd carrier (5) is moved in a longitudinal direction
relative to said deformable surrounding wall (612) so as to bring said head
end wall (613) to abut against and to be retained at said surrounding
shoulder (24), thereby displacing said syringe from the position of use to a
disposal position, and a retaining segment (618) which is in a first frictional
engagement with said retained region (527) by virtue of a first frictional force
so as to confine, in cooperation with said yielding segment (610) and said
pushing region (516), a fluid-tight surrounding area, and which is configured
such that the first frictional force is diminished so as to facilitate release of
said retained region (527) from said retaining segment (618) when said
yielding segment (610) is depressed by said pushing region (516), thereby
disrupting the fluid-tightness of said surrounding area and rendering the
syringe unreusable.
2. The single-use syringe as claimed in claim 1, wherein said surrounding
trailing end (616) of said deformable surrounding wall (612) is in fluid-
tight and slidable engagement with said rear larger-diameter portion, said
outer surrounding wall surface (622) of said deformable surrounding wall
(612) being configured to cooperate with said upper sealing end (615) to
define an annular compressible chamber (621) between said upper sealing
end (615) and said surrounding trailing end (616) such that, subsequent
to abutment of said head end wall (613) against said surrounding
shoulder (24), said yielding segment (610) is depressed by said pushing
region (516) radially and outwardly to result in deformation of said
deformable surrounding wall (612) which moves said inner surrounding
wall surface (617) radially and towards said rear larger-diameter portion
so as to diminish the first frictional force, thereby disrupting the fluid-
tightness of said surrounding area, and facilitating disengagement of said
carrier (5) from said deformable sealing member (6) when said carrier (5)
is moved rearwards by said plunger (4) towards said rearward opening
(232).
3. The single-use syringe as claimed in claim 2, wherein said intermediate
surrounding portion (51,52) of said carrier (5) comprises:
a tubular pushing segment (51) serving as said pushing region (516), said
pushing segment (51) being coupled and formed integrally with said tail
portion (517), and terminating at an opened end (513), said pushing segment
(51) having an inner surrounding engaging region (514) which extends in the
longitudinal direction to be communicated with said opened end (513), and
which surrounds the axis (X) to define a cavity (511), and
a tubular retained segment (52) serving as said retained region (527),
said retained segment (52) having an outer surrounding retained wall (521)
which extends from said head portion (523) in the longitudinal direction to
terminate at an outer engaging end (524) and which is configured to be
insertable into said cavity (511) to bring said outer surrounding retained wall
(521) into a second frictional engagement with said inner surrounding
engaging region (514) such that, subsequent to the disruption of the fluid-
tightness of said surrounding area, said head portion (523) is blocked by said
surrounding shoulder (24) from moving further so as to permit said outer
surrounding retaining wall (521) to be in the second frictional engagement
with said inner surrounding engaging region (514), thereby facilitating
disengagement of said carrier (5) from said deformable sealing member (6).
4. The single-use syringe as claimed in claim 3, wherein said tubular pushing
segment (51) has a vent hole (515) in fluid communication with said
cavity (511);
5. The single-use syringe as claimed in claim 2, wherein said deformable
surrounding wall (612) is configured such that when said inner
surrounding wall surface (617) is moved radially and towards said rear
larger-diameter portion, said deformable surrounding wall (612) squeezes
air out of said annular compressible chamber (621) so as to permit said
outer surrounding wall surface (622) to abut against said rear larger-
diameter portion.
6. The single-use syringe as claimed in claim 1, comprising:
a passageway interrupting member (623,63,64,65,67,68,69) which is
disposed to be engaged with one of said head portion (523) of said carrier
(5) and said head end wall (613) of said deformable sealing member (6),
and which is configured such that once the fluid-tightness of said
surrounding area is disrupted, said passageway interrupting member
(623,63,64,65,67,68,69) is forced by a corresponding one of the said head
portion (523) and said head end wall (613) to plug said front passageway
(22).
7. The single-use syringe as claimed in claim 6, wherein said passageway
interrupting member (623,63,64,67,68) has frictional ribs
(625,626,631,641,675,685) disposed thereon for frictional engagement
with said smaller-diameter portion.
8. The single-use syringe as claimed in claim 6, wherein said passageway
interrupting member (65,69) has two prongs (651) which acquire a
biasing force to reinforce plugging-in engagement of said passageway
interrupting member (65,69) with said front smaller-diameter portion.
9. The single-use syringe as claimed in claim 6, wherein said passageway
interrupting member (623) is integrally formed with the corresponding
one of said head portion (523) and said head end wall (613) such that
once the fluid-tightness of said surrounding area is disrupted, the
diminution of the first frictional force enables disengagement of said
retained region (527) from said retaining segment (618), thereby
permitting disengagement of said deformable sealing member (6) from
said carrier (5) when said carrier (5) is moved rearwards by said plunger (4)
toward said rearward opening (232).
10.The single-use syringe as claimed in claim 6, wherein said head portion
(523) of said carrier (5) has an inner peripheral grip wall (55) which
defines an insert bore (56) extending along the axis (X) through said
intermediate surrounding portion and which is of a dimension such that
said inner peripheral grip wall (55) acquires a radial flexibility, thereby
yielding radially and towards the axis (X) to the first frictional force so as
to facilitate disruption of the fluid-tightness of said surrounding area.
11. The single-use syringe as claimed in claim 10, wherein said passageway
interrupting member (67,68,69) has a gripped end (674) which is retained
in said insert bore (56) when said inner peripheral grip wall (55) yields to
the first frictional force, and a plug head (677) which is opposite to said
gripped end (674) in the longitudinal direction, and which extends
forwardly and outwardly of said head end wall (613) of said deformable
sealing member (6) such that once the fluid-tightness of said surrounding
area is disrupted, the diminution of the first frictional force upon the first
frictional engagement lessens the degree of yielding towards the axis (X)
so as to permit said inner peripheral grip wall (55) to release said gripped
end (674), thereby permitting said plug head (677) to be retained in said
front passageway (22) when said carrier (5) is moved in the longitudinal
direction relative to said deformable surrounding wall (612).
12. The single-use syringe as claimed in claim 11, wherein said intermediate
surrounding portion has a pulling region (57) which is disposed rearwardly
of said pushing region (516), said inner surrounding wall surface of said
deformable surrounding wall (612) having a pulled segment (62) which is
disposed between said yielding segment (610) and said retaining segment
(618) and which is configured such that said pulling region (57) is
displaced to abut against said pulled segment (62) subsequent to the
disruption of the fluid-tightness of said surrounding area, and such that
said pulling region (57) is forced by a rearward movement of said carrier
(5) to depress said pulled segment (62) to move towards said rearward
opening (232), thereby permitting movement of said deformable sealing
member (6) with said carrier (5) so as to bring said plug head (677) to
disengage from said head end wall (613) of said deformable sealing
member (6) when said plug head (677) is retained in said front
passageway (22).
13. The single-use syringe as claimed in claim 1, wherein said carrier (5)
comprises a projection member (53) which is integrally formed with said
head portion (523) and which extends through said head end wall (613)
of said deformable sealing member (6) such that when said carrier (5) is
moved rearwards, said projection member (53) is disengaged from said
head end wall (613) of said deformable sealing member (6).

The invention relates to a single-use syringe comprises a
barrel (2) having front and rear passageways (22,21) and a
shoulder (24) disposed therebetween, a plunger (4) movable in the
rear passageway (21), a carrier (5) having a tail portion (517)
extending from a front end wall (41) of the plunger (4), and
pushing and retained regions (516, 527) formed forwardly of the
tail portion (517), and a deformable sealing member (6) in fluid-
tight and slidable engagement with the barrel (2), the sealing
member (6) includes an inner surrounding wall surface (617) with
a yielding segment (610) engaging the pushing region (516), and a
retaining segment (613) in frictional engagement with the
retained region (527) by a frictional force so as to confine a
fluid-tight surrounding area. The frictional force is diminished
when the yielding segment (610) is depressed by the pushing
region (516) so as facilitate release of the retained region
(527) from the retaining segment (613), thereby disrupting the
fluid-tightness of the surrounding area and rendering the
syringe unreusable.

Documents:

573-KOL-2004-FORM-27.pdf

573-kol-2004-granted-abstract.pdf

573-kol-2004-granted-claims.pdf

573-kol-2004-granted-correspondence.pdf

573-kol-2004-granted-description (complete).pdf

573-kol-2004-granted-drawings.pdf

573-kol-2004-granted-examination report.pdf

573-kol-2004-granted-form 1.pdf

573-kol-2004-granted-form 18.pdf

573-kol-2004-granted-form 2.pdf

573-kol-2004-granted-form 26.pdf

573-kol-2004-granted-form 3.pdf

573-kol-2004-granted-form 5.pdf

573-kol-2004-granted-reply to examination report.pdf

573-kol-2004-granted-specification.pdf

« Previous Patent

Next Patent »

Patent Number

234008

Indian Patent Application Number

573/KOL/2004

PG Journal Number

18/2009

Publication Date

01-May-2009

Grant Date

29-Apr-2009

Date of Filing

21-Sep-2004

Name of Patentee

MING-JENG SHUE

Applicant Address

NO. 14, LANE 8, CHUNG-I ST., HSI DIST., TAICHUNG CITY

Inventors:

#	Inventor's Name	Inventor's Address
1	MING-JENG SHUE	NO. 14, LANE 8, CHUNG-I ST., HSI DIST., TAICHUNG CITY
2	DEBORAH HUANG	7F, NO.5, SEC.3, LIU-CHUN ST., CHUNG DIST., TAICHUNG CITY
3	PHILLIP SHUE	NO.14, LANE 8, CHUNG-I ST., SHI-DIST, TAICHUNG CITY

PCT International Classification Number

A61M 5/50

PCT International Application Number

N/A

PCT International Filing date

PCT Conventions:

#	PCT Application Number	Date of Convention	Priority Country
1			NA