Title of Invention

"A DEVICE FOR INSERTING AN O-RING INTO LPG CYLINDER VALVES"

Abstract

A device for inserting O-Rings into the valves of LPG Cylinders particularly for valves with internal O-rings. The device comprises a housing and jaws mounted pivotably on pivot pins in said housing. A piston slidably mounted in said housing is provided, wherein lower part of said piston being formed into an axisymmetric cam to actuate said jaws for squeezing the O-ring and lowest end of the piston is extended into the shape of a cylindrical push pin to push the squeezed O-ring into the LPG cylinder valve. Further, a mouthpiece screwed into the lower end of the housing and sized to slip over the mouth of said valve containing an aperture through which said piston pushes said O-ring into said valve.

Full Text

The present invention relates to a device for inserting O-Rings into the valves of LPG Cylinders. Background of the invention LPG Cylinders contain a valve that is used both filling the cylinder and withdrawing gas from it. The valves contain an O-ring inside the valve mouth. The purpose of this O-ring is to seal the valve against the nozzle of the regulator connected to the valve for controlled gas withdrawal. Leakage from this O-ring will allow gas to escape to the atmosphere and create a hazard to the user of the cylinder. The integrity of the valve O-ring is regularly checked at the filling Plant and all leaking O-rings are removed and replaced by new ones. The insertion of new O-rings into the valves is today done by manual means assisted by simple tools. When the highest integrity against leakage is desired it may be necessary to change the O-ring of all the cylinders every time they are received for refilling. This will require a device capable of performing several hundred O-ring insertions per hour. Manual devices are not capable of satisfying this speed requirement. The O-ring insertion is complicated by the fact that the outer diameter of the O-ring is greater than the inner diameter of the valve mouth. In order to insert the O-ring it must first be deformed so that it can be pushed into the valve mouth. It is desirable that this deformation be an axially symmetric radial squeeze which reduces the O-ring diameter while retaining its circular shape. Non axisymmetric deformation risks damage to the O-ring during insertion with subsequent leakage problems. For the same reason it is also important that the push of the O-ring into the valve in only be performed after the squeezing step is complete and that the axis of the O-ring is vertical when it is pushed down into the valves. When a large number of O-rings change are to be performed it is also desirable that the device used should be amenable to automation. Object and summary of the invention The object of this invention is to overcome the above drawbacks by providing a device for inserting O rings into a LPG cylinder valve comprising: a housing, - jaws mounted pivotably on pivot pins in said housing, - a piston slidably mounted in said housing for actuating the jaws and pushing the O-ring into the valve, - lower end of said piston is formed into an axisymmetric cam to actuate said jaws for squeezing the O-ring, - lowest end of the piston is extended into the shape of a cylindrical push pin to push the squeezed O-ring into the LPG cylinder valve, a mouthpiece screwed into the lower end of the housing and sized to slip over the mouth of said valve containing an aperture through which said piston pushes said O-ring into said valve, - a spring outside said housing to return said piston to its original position, and - a rubber squeeze ring to return said jaws to their normal position. The jaws are either two or more depending upon the type and size of said valve and O-ring. The slot is provided in the housing to place the O-ring between the jaws and on the top surface of said mouthpiece. The cam has a conical part to bear against the upper end of the jaws. The squeeze ring is made of soft rubber and stretches to enable the jaws to pivot around said pivot pins. The squeezed diameter of the O-ring is less than the inner diameter of the mouth of said valve. The housing is provided with a top face to stop the downward motion of the piston. Brief description of Accompaning Figure 1 shows a sectional view of a known LPG cylinder valve with the O-ring in it. Figure 2 shows a sectional view of the device for inserting O ring into a LPG cylinder valve according to the present invention. Figure 3 shows a sectional view of the O-ring insertion device with an O-ring loosely dropped into it lowering onto the valve according to the present invention. Figure 4 shows a sectional view of the O-ring insertion device in the action of squeezing the O-ring according to the present invention. Figure 5 shows a sectional view of the O-ring insertion device pushing the O-ring into the valve according to the present invention. Detailed description of the accompanying drawings To clarify the background, Figure 1 shows a conventional LPG valve (10) with an internal O-ring (11) mounted in groove (12) inside the mouth of the valve. Note that there is the significant difference between the valve mouth inner diameter (dl) and the O-ring diameter (d2). Figure 5 shows a sectional view of the O-ring insertion device pushing the O-ring into the valve according to the present invention. Detailed description of the accompanying drawings To clarify the background, Figure 1 shows a conventional LPG valve (10) with an internal O-ring (11) mounted in groove (12) inside the mouth of the valve. Note that there is the significant difference between the valve mouth inner diameter (dl) and the O-ring diameter (d2). Figure 2 shows a sectional view of the O-ring insertion device. The device consists of a housing (100) which contains the active parts of the present invention which are explained as follows. A set of jaws (120) mounted pivotably on pivot pins (170) in the housing is provided for squeezing the O ring for making its diameter less than the inner diameter of the cylinder valve. In the figure, only one jaw has been depicted for the purpose of illustration. In a working model of the O ring insertion device at least two jaws are be used. Further, a Piston (140) is provided such that it is slidably mounted in the housing. The lower part of the piston is formed into an axisymmetric cam (150) to actuate the jaws (120) for squeezing the O ring. The lowest end of the piston is extended into the shape of a cylindrical push pin (160) to push the squeezed O-ring into the valve. A mouthpiece (110) is screwed into the lower end of the housing and sized to slip over the mouth of said valve containing an aperture through which said piston pushes said O-ring into said valve. In addition, a spring (300) is provided outside said housing to return said piston to its original position, and rubber squeeze ring (130) is provided to return said jaws to their normal position. Figure 3 shows the sectional view of the device with an O-ring (11) loosely dropped into it from slot (105). In this condition the O-ring comes to rest between the three jaws (120) and on the top surface of the mouth piece (110). In figure 3, the device is being lowered onto the valve (10) whose O-ring has been removed prior to this operation. This lowering can be done by a pneumatic cylinder connected to the top of the piston (140). However, the deice is versatile and lightweight enough that it can also adopted for handheld use. Figure 4 shows the device lowered onto the valve. In this condition the socket (111) in the mouthpiece has slipped over the mouth of the valve. Continued downward force on the piston (140) (whether manually or pneumatically applied) causes it to slide down within the housing (100). This causes the conical part (151) of the cam (150) to bear against the upper end (121) of the jaws. The squeeze ring (130) is of soft rubber and stretches to enable the jaws to pivot around the pivot pins (170). This causes the lower end (122) of the jaws (120) to close around the O-ring (11) for clarity only the jaw is shown on the figure. As mentioned earlier in the specification, in practice there are at least two jaws systematically arranged around the axis of the device. The said action of the jaws aligns the O-ring concentrically with the valve and also applies a radial squeeze onto it. This squeezing action intensifies until the piston has lowered sufficiently such that the upper end of the jaw rides against the cylindrical portion (152) of the cam. The cam and jaws are so dimensioned and arranged that at this point the squeezed diameter of the O-ring is slightly less than the inner diameter of the valve mouth. Further downward movement of the piston causes the push pin (160) to contact the top of the squeezed O-ring and force it down through the aperture (112) in the mouthpiece and into the mouth of the valve. Downward motion continues until the movement of the piston is arrested by its contact with the top face*(102) of the housing. The length of the push pin is such that in this condition the O-ring is in the position of the groove (12) in the valve. When the O-ring reaches the groove it snaps into it and attain its final fitted diameter. This condition is shown in Figure 5. The device can then be lifted from the valve and the action of spring (300) and the squeeze ring (130) returns all parts to their original position of Figure 2. The entire operating cycle is accomplished by a single stroke of the piston. In practice the sequence form Figures 3 to 5 can be completed in a time of the order of one second. This makes this device very suitable for automatic operation. I claim: 1. A device for inserting an O-ring into LPG cylinder valve comprising: a housing, - jaws mounted pivotably on pivot pins in said housing, a piston slidably mounted in said housing for actuating the jaws and pushing the O-ring into the valve, lower end of said piston is formed into an axisymmetric cam to actuate said jaws for squeezing the O-ring, lowest end of the piston is extended into the shape of a cylindrical push pin to push the squeezed O-ring into the LPG cylinder valve, a mouthpiece screwed into the lower end of the housing and sized to slip over the mouth of said valve containing an aperture through which said piston pushes said 0-ring into said valve, a spring outside said housing to return said piston to its original position, and a rubber squeeze ring to return said jaws to their normal position. 2. The O-ring insertion device as claimed in claim 1 wherein said jaws are either two or more depending upon the type and size of said valve and O-ring. 3. The O-ring insertion device as claimed in claim 1 wherein a slot is provided in the housing to place the O-ring between the jaws and on the top surface of said mouthpiece. 4. The O-ring insertion device as claimed in claim 1 wherein said cam has a conical part to bear against the upper end of the jaws. 5. The O-ring insertion device as claimed in claim 1 wherein said squeeze ring is made of soft rubber and stretches to enable the jaws to pivot around said pivot :^A. j pins. 6. The O-ring insertion device as claimed in claim 1 wherein the squeezed diameter of the O-ring is less than the inner diameter of the mouth of said valve. 7. The O-ring insertion device as claimed in claim 1 wherein said housing is provided with a top face flage which the flage of the piston to shop the further down of the piston 8. The O-ring insertion device substantially as herein described with reference to and as illustrated in the accompanying drawings.

Documents:

1064-del-2003-abstract.pdf

1064-del-2003-claims.pdf

1064-del-2003-complete specification (granted).pdf

1064-del-2003-correspondence-others.pdf

1064-del-2003-correspondence-po.pdf

1064-del-2003-description (complete).pdf

1064-del-2003-drawings.pdf

1064-del-2003-form-1.pdf

1064-del-2003-form-19.pdf

1064-del-2003-form-2.pdf

1064-del-2003-form-3.pdf

1064-del-2003-pa.pdf

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