Title of Invention

EYE-TYPE BUTTONHOLE SEWING MACHINE

Abstract

An eye-type buttonhole sewing machine comprises an x-y table (9), on which a work-piece clamp (11) is disposed, which is mounted for dis-placement in the x direction. The work-piece clamp (11) is operated by means of a pneumatically actuated piston-cylinder drive (20) which is mounted on the work-piece clamp (11) and which is connected to a com-pressed-air hose (28). This compressed-air hose (28) is releasably connected to the piston-cylinder drive (20) by means of a hose coupling (32).

Full Text

Eye-Type Buttonhole Sewing Machine The invention relates to an eye-type buttonhole sewing machine according to the preamble of claim 1. In an eye-type buttonhole sewing machine of the generic type, which is known from EP 1 354 993 A2, the work-piece clamp is embodied in such a way that a bottom clamping plate is joined to the x-y table for displacement in the x direction, whereas a top clamping plate, which is joined to the bot-tom clamping plate, can be pressed against the bottom clamping plate by means of a pneumatically actuated piston-cylinder drive, clamping a work piece. The pneumatically actuated piston-cylinder drive can be actuated by compressed air by way of a flexible compressed-air hose. DE 28 07 895 C2 describes a sewing machine with a work-piece clamp, the clamping drive of which has pressure-fluid storage means of its own which, during sewing, are separated from a compressed-air hose for com-pressed-air supply. For charging, the compressed-air storage means are connected to the compressed-air hose by means of a hose coupling. As a rule, eye-type buttonhole sewing machines are provided with a hook bearing which is disposed below the bottom clamping plate, with a so-called looper thread being supplied thereto. Threading this looper thread, as well as cleaning and maintenance jobs, require the work-piece clamp to be removed from its position of operation. In doing so, problems are posed by the compressed-air hose being tightly united with the piston-cylinder drive. -2- It is an object of the invention to improve the eye-type buttonhole sewing machine of the generic type in such a way that the hook bearing is easily accessible. According to the invention, this object is attained by the features of the characterizing part of claim 1. Due to the fact that a releasable coupling is provided between the pneumatically actuated piston-cylinder drive and the compressed-air hose, it is easily possible to remove the work-piece clamp together with the bottom clamping plate which covers the hook bearing. Likewise it is easily possible to produce the connection. Producing and re-leasing the coupling takes place by the motion, as desired, of the work-piece clamp upon removal and placement. The coupling members interen-gage when in operation, i.e. they need not be kept against one another by corresponding force - as is the case with flatly adjoining coupling mem-bers. The further development according to claim 2 ensures that the motions in the x and y direction of the x-y table and the work-piece clamp relative to each other are not affected. In keeping with the further development according to claim 3, it is ensured that the work-piece clamp does not possess a hose end or the like that stands out downwards. In this regard, the coupling member is largely pro-tected even when the work-piece clamp is not properly removed or in-serted. The further development according to claim 4 ensures that the coupling condition is produced by self-centering of the coupling members that are slipped into each other. -3- An especially simple embodiment is offered by claim 5, according to which the necessary displaceability in the x and y direction is simultane-ously implemented in the coupling itself. An alternative design is specified in claims 6 to 8. The further development according to claims 7 and 8 ensures another sim-plification in handling, thus saving time when the coupling is released and produced. The development according to claim 9 ensures that the work-piece clamp and the bottom clamping plate cannot be lifted off the x-y table in the posi-tion of operation of the work-piece clamp. Two exemplary embodiments of the invention will be explained below, taken in conjunction with the drawings. Further features, advantages and details of the invention will become ap-parent from the ensuing description, taken in conjunction with the drawing, in which Fig. 1 is a side view, partly broken away, of an eye-type buttonhole sew-ing machine; Fig. 2 is a sectional view of the sewing machine on the line 11-11 of Fig. 1 on an enlarged scale as compared to Fig. 1; -4- Fig. 3 is an illustration of a clamping drive corresponding to the arrow III of Fig. 1 on an enlarged scale as compared to Fig. 1; Fig. 4 is a sectional view, on the line IV-IV of Fig. 3, of a bottom clamp-ing plate with a clamping drive mounted thereon; Fig. 5 is a perspective view of the drive bearing case of the clamping drive; Fig. 6 is an illustration, corresponding to Fig. 4, of a second embodiment of a coupling member mounted on an x-y table on an enlarged scale; and Fig. 7 is a view of the coupling member in accordance with the arrow VII of Fig. 6. As seen in Fig. 1, an eye-type buttonhole sewing machine is C-shaped, having a top arm 1, a bottom base plate 2 in the form of a housing and an approximately vertical standard 3 that unites the two. An arm shaft 4 is conventionally located in the arm 1; it is drivable by a drive motor (not shown). The drive of a needle bar 5, which is vertically displaceable in the z direction and has a needle 6, and a jogging drive therefor conventionally derive from the arm shaft 4. A hook bearing 7 is disposed in the base plate 2 underneath the needle bar 5 and the needle 6; it is drivable in rotation about a vertical axis 8. The drive of the hook bearing 7 conventionally de-rives from the arm shaft 4. An x-y table 9 is disposed on the base plate 2; it is a cross slide which is displaceable in two horizontal coordinate directions, namely the x direction -5- and the y direction. The x-y table 9 is conventionally embodied, as known for example from DE 198 07 771 Al (corresponding to U.S. patent 6 095 066). Actuation of the x-y table 9 takes place by means of an x dirve and a y drive, which may be electric positioning motors, preferably stepper motors, but just as well controllable d.c. motors. These drives are not shown. A two-piece bottom clamping plate is disposed on the x-y table 9, of which only the - seen in the y direction in Figs. 1 and 2 - bottom right clamping plate 10 is illustrated, which supports itself on the x-y table 9 for displace-ment in the x direction. This design is known from EP 1 354 993 A2 (cor-responding to U.S. serial number 10/410 467), to which reference is made. Each bottom clamping plate 10 is a part of a work-piece clamp 11. The bottom clamping plate 10 covers the hook bearing 7 and must be removed when a looper thread is threaded. The work piece clamp on the left of the needle 6 in Fig. 2 is not illustrated, but is disposed in mirror symmetry of the work-piece clamp 11 opposite the needle 6. Only the work-piece clamp 11 on the right of the needle 6 is described. Each work-piece clamp 11 comprises a double-armed bearing lever 12 which is comprised of a pivoted lever 13 and a sliding lever 14. On its free end the sliding lever 14 is provided with a top clamping plate 15. The piv-oted lever 13 is located in the drive and bearing case 17, pivoting about a pivoting axis 16. By means of screws 18 the case 17 fixed to the underside of the bottom clamping plate 10. By their contact area both parts are united by means of liquid sealant (not shown) for compressed-air tightness. The pivoted lever 13 and the sliding lever 14 are joined to each other longitudi-nally adjustably in the y direction by means of a sliding and locking con-nection 19. -6- The case 17 is a part of a clamping drive 20 for the work-piece clamp 11. The case 17 includes a continuous cylindrical chamber 21 which is open at the bottom and closed at the top by the bottom clamping plate 10; a piston 22 is disposed therein for sealed up and down motion. This piston 22 com-prises a piston rod 23 which projects downwards from the cylindrical chamber 21 and which, by means of a joint 24, is articulated to the facing end 25 of the pivoted lever 13 i.e., of the bearing lever 12. A compressed-air supply duct 26 is formed in the case 17 by the side of the cylindrical chamber 21; at the top of the case 17 it is connected to the cylindrical chamber 21 by way of an overflow channel 27. At the bottom of the case 17, a compressed-air hose 28 mouthes into the compressed-air supply duct 26; it is connected to an electromechanically operable 3/2-port directional control valve 29, a so-called solenoid valve. As can be seen from the de-scription, the clamping drive 20 is a unilaterally pneumatically actuated piston-cylinder unit. A pre-loaded extension spring 30 is fixed in the vicinity of the end 25 of the pivoted lever 13; the other end of the spring 30 is mounted on the top side of the case 17 so that the bearing lever 12, together with the top clamping plate 15, is lifted off the bottom clamping plate 10 when the pis-ton 22 is not loaded from above by compressed air. If, however, com-pressed air acts from above on the piston 22, the sliding lever 14 of the bearing lever 11, together with the top clamping plate 15, is being pressed against the bottom clamping plate 10, with a work piece 31, upon opera-tion, being clamped between the top clamping plate 15 and the bottom clamping plate 10. -7- The compressed-air hose 28 is connected to the case 17 by means of a re-leasable hose coupling 32. To this end, a supporting plate 33 is mounted by screws 34 on the bottom side of the x-y table 9, extending in parallel to the bottom clamping plate 10 as far as underneath the case 17. By means of an elbow hose connection 35, the compressed-air hose 28 is fixed to this sup-porting plate 33 which is stationary in relation to the x-y table 9. The hose coupling 32 itself is constituted by a hopper portion 36 that adjoins the compressed-air supply duct 26 and by a connecting hose 37 that passes through the hopper portion 36 into the duct 26. The hopper portion 36 ex-pands downwards towards the supporting plate 33. When coupled, the flexibly resilient connecting hose 37 passes through the hopper portion 36 in the z direction into the compressed-air supply duct 26 where it is sealed towards the case 17 by means of an ring seal 38 so that, in the coupled condition seen in Fig. 4, a compressed-air-tight connection is produced be-tween the compressed-air hose 28 and the compressed-air supply duct 26. Consequently, the hopper portion 36 is a receptacle of a coupling member, whereas the connecting hose 37 is a projecting part of another coupling member which is inserted in the z direction into the receptacle. The hopper-style design of the portion 36 strongly facilitates the insertion and centering of the connecting hose 37. When the bottom clamping plate 10, together with the work-piece clamp 11, is removed upwards from the x-y table 9, then the compressed-air hose 28, which is connected with the x-y table 9 via the supporting plate 33, and the elbow hose connection 35 and the connecting hose 37 stay on the base plate 2 of the sewing machine, whereas the work-piece clamp 11 and the bottom clamping plate 10 and the clamping drive 20, inclusive of the hop-per portion 36 and the ring seal 38, is withdrawn upwards from the con-necting hose 37. As a safeguard against the work-piece clamp 11 and the -8- bottom clamping plate 10 inadvertently lifting off the x-y table, the clamp-ing plate 10 is secured by a retaining rib 39 which is fixed to the bottom part of the pivoted lever 13. The retaining rib 39 may for instance be the head of a securing screw. As seen in Figs. 3 and 4, in the position of opera-tion seen in the drawing, the retaining rib 39 backs up the supporting plate 33 in the vicinity of its edge 33a which is shown by dashes in Fig. 3. When the cylindrical chamber 21 is vented, the bearing lever 12, by the load of the pre-stressed extension spring 30, is in the upwards pivoted position so that the retaining rib 39 no longer backs up the supporting plate 33. As a result, the bottom clamping plate 10 i.e., the work-piece clamp 11, can be moved slightly in the y direction in relation to the x-y table and then lifted off upwardly in the z direction. As mentioned at the outset, the bottom clamping plate 10 is displaceable by some short length in the x direction in relation to the x-y table 9, which results from the design of the sewing machine as an eye-type buttonhole sewing machine. This slight displacement in the x direction is effected by means of a sliding drive 40, with only a drive lever 41 thereof being illus-trated, which acts of the bottom clamping plate 10. The motions, men-tioned above, of the bottom clamping plate 10 in the x-y plane are possible because, in the hopper portion 36, the connecting hose 37 is able to deform laterally in the x direction and in the y direction, corresponding to the bot-tom opening area of the hopper portion 36. These motions of few millime-ters in the x and y direction are possible. In an alternative embodiment of a hose coupling 32' according to Figs. 6 and 7, a slide 42 in the form of a plate is mounted on the supporting plate 33' for the mentioned displacement of the clamping plate 10 on the x-y plane. To this end, the slide 42 comprises bolts 43 which project down- -9- wards and pass through holes 44 drilled in the supporting plate 33', these holes 44 having a diameter that clearly exceeds that of the bolts 43, there being corresponding play 45 in the x and y direction. The slide 42 is se-cured against lift-off by circlips 46 which are mounted the bolts 43 under-neath the supporting plate 33'. The elbow hose connection 35' of the compressed-air hose 28 passes through a hole 47 drilled in the supporting plate 33', between which and the elbow hose connection 35 some play 48 exists, corresponding to the play 45. The elbow hose connection 35' is mounted on the slide 42, where it is tightly united with a connecting pipe 49 which projects upwardly and is rigid and which is inserted into the hopper portion 36 of the case 17. Upon displacement of the bottom clamping plate 10 in the x and y direction, the connecting pipe 49, together with the case 17 and the slide 42, moves on the x-y plane in relation to the supporting plate 33' which is tightly joined to the x-y table 9. The motions thereof are absorbed and compensated by the flexible compressed-air hose 28. - 10-Claims 1. An eye-type buttonhole sewing machine, comprising a base plate (2); a needle (6) which is drivable in a z direction by means of an arm shaft (4); a hook bearing (7) which is disposed underneath the needle (6) in the base plate (2); an x-y table (9) which is mounted on the base plate (2) and displace-able in an x direction and in a y direction; at least one work-piece clamp (11) which is mounted on the x-y table (9) for displacement in the x direction and which is displaceable by means of a sliding drive (40); — the work-piece clamp (11) having a bottom clamping plate (10) which is detachable from the x-y table (9) upwards in the z direc-tion and attachable on the x-y table (9) from above in the z direc-tion, and — the work-piece clamp (11) having a top clamping plate (15) which is articulated to the bottom clamping plate (10); a clamping drive (20) which is mounted on the bottom clamping plate (10) and constituted by a pneumatically operable piston-cylinder drive for actuation of the top clamping plate (15); and a compressed-air hose (28) which is connected to the clamping drive (20) for supply of the clamping drive (20) with compressed air; characterized in that the compressed-air hose (28) is releasably connected to the clamp-ing drive (20) by means of a hose coupling (32, 32'); -11- in that the hose coupling (32, 32') comprises a coupling member which is connected to the clamping drive (20) and a coupling member which is con-nected to the compressed-air hose (28): and in that a coupling member comprises a receptacle and the other coupling member comprises a projecting part which is insertable in the z direction into the receptacle for production of a coupling union and which is remov-able in the z direction from the receptacle for release of the coupling union. 2. An eye-type buttonhole sewing machine according to claim 1, charac-terized in that the hose coupling (32, 32') has motional play in the x-y di-rection. 3. An eye-type buttonhole sewing machine according to claim 1 or 2, characterized in that the coupling member which is provided with the receptacle is formed on the clamping drive (20). 4. An eye-type buttonhole sewing machine according to one of claims 1 to 3, characterized in that the coupling member which is provided with the receptacle comprises a hopper portion (36) that expands outwards. 5. An eye-type buttonhole sewing machine according to one of claims 1 to 4, characterized in that the projecting part is a flexible connecting hose (37). 6. An eye-type buttonhole sewing machine according to one of claims 2 to 5, characterized in that the projecting coupling member is a connecting pipe (49). -12- 7. An eye-type buttonhole sewing machine according to claim 6, charac-terized in that the connecting pipe (49) is rigid. 8. An eye-type buttonhole sewing machine according to claim 6 or 7, characterized in that the coupling member that comprises the projecting part is connected to the x-y table (9) for displacement in the x-y direction. 9. An eye-type buttonhole sewing machine according to one of claims 1 to 8. characterized in that the work-piece clamp (11), in a position of opera-tion, is secured in the z direction by means of a safeguard device. An eye-type buttonhole sewing machine comprises an x-y table (9), on which a work-piece clamp (11) is disposed, which is mounted for dis-placement in the x direction. The work-piece clamp (11) is operated by means of a pneumatically actuated piston-cylinder drive (20) which is mounted on the work-piece clamp (11) and which is connected to a com-pressed-air hose (28). This compressed-air hose (28) is releasably connected to the piston-cylinder drive (20) by means of a hose coupling (32).

Documents:

00046-kol-2005-abstract.pdf

00046-kol-2005-claims.pdf

00046-kol-2005-correspondence-1.1.pdf

00046-kol-2005-correspondence-1.2.pdf

00046-kol-2005-correspondence-1.3.pdf

00046-kol-2005-correspondence.pdf

00046-kol-2005-description(complete).pdf

00046-kol-2005-drawings.pdf

00046-kol-2005-form-1-1.1.pdf

00046-kol-2005-form-1.pdf

00046-kol-2005-form-18.pdf

00046-kol-2005-form-2.pdf

00046-kol-2005-form-26.pdf

00046-kol-2005-form-3.pdf

00046-kol-2005-priority document(other)-1.1.pdf

00046-kol-2005-priority document(other).pdf

00046-kol-2005-priority document-1.1.pdf

00046-kol-2005-priority document.pdf

46-kol-2005-granted-abstract.pdf

46-kol-2005-granted-claims.pdf

46-kol-2005-granted-correspondence.pdf

46-kol-2005-granted-description (complete).pdf

46-kol-2005-granted-drawings.pdf

46-kol-2005-granted-examination report.pdf

46-kol-2005-granted-form 1.pdf

46-kol-2005-granted-form 18.pdf

46-kol-2005-granted-form 2.pdf

46-kol-2005-granted-form 26.pdf

46-kol-2005-granted-form 3.pdf

46-kol-2005-granted-form 5.pdf

46-kol-2005-granted-priority document.pdf

46-kol-2005-granted-reply to examination report.pdf

46-kol-2005-granted-specification.pdf

46-kol-2005-granted-translated copy of priority document.pdf