GB2380732A

GB2380732A - A tamper-evident cap for use on gas cylinders

Info

Publication number: GB2380732A
Application number: GB0127678A
Authority: GB
Inventors: Sean Mccourt
Original assignee: LPG Ltd
Current assignee: LPG Ltd
Priority date: 2001-10-12
Filing date: 2001-11-19
Publication date: 2003-04-16
Anticipated expiration: 2021-11-19
Also published as: IE20010904A1; GB2380732B; GB0127678D0

Abstract

A tamper-evident cap 10 for use with a valve 44 having a circumferential groove (fig 3, 46) comprises a body 12 having at least one aperture 22, which is in register with the circumferential groove (46), and a coupling 14 having at least one protrusion 26 that extends through the aperture 22 and into the circumferential groove (46), the coupling 14 being irreversibly removable from the body 12. The coupling 14 may have an arcuate portion 24 and the at least one protrusion may extend radially inwardly from the arcuate portion 24. The body 12 may include a pair of oppositely disposed apertures 22 in a channel 20, and the coupling 14 may include a pair of oppositely disposed protrusions 26, to extend through said opposite disposed apertures 22. The coupling 14 may also be provided with a tab 28 extending from the arcuate portion 24, to facilitate detachment of the coupling 14 from the body 12. The arcuate portion 24 may be provided with at least one point of relative weakness to allow the arcuate portion 24 to break, when the tab 28 is pulled, which may be provided by a notch on either side of the tab 28. The coupling 14 may be split, with opposed free ends being provided with a pair of irreversibly interlocking jaws 32, 34. The body 12 may further be provided with a collar 54 connected thereto by a strap 56.

Description

A TAMPER EVIDENT CAP The present invention relates to a tamper evident cap, and in particular to a tamper evident cap for use on butane or propane gas cylinders, such as liquefied petroleum gas (LPG) cylinders filled and distributed by Calorgasm.

At present, such LPG bottles contain approximately 11.34 Kg of LPG when full, at a pressure of approximately 35 psig (2.41 bar), and can be repeatedly refilled once emptied. It is important that such refilling be carried out in a controlled manner and to an exact specification, as incorrectly refilled bottles may be unsafe to use and can result in a fire or explosion due to leaking gas.

Despite this fact, the illegal trade of unauthorised refilling of such LPG bottles is considerable, causing a risk to the end users of such refilled bottles, in addition to damage to the legitimate business and goodwill of the owner of the LPG bottle.

Conventionally, all new LPG bottles, or alternatively LPG bottles which have been refilled, are provided with a cap which is reversibly threaded onto the valve of the LPG cylinder. Inside the cap is a rubber insert which abuts against an annulus which surrounds the valve needle. The insert is adapted to hold a pressure of approximately 72.5 psi (5 bar) in the event that the valve leaks gas, and also serves as a protective feature which maintains the needle free of contamination. After an LPG cylinder has been filled

and the cap fitted, the cap is covered with a plastic wrapper which is shrunk onto the cap by means of a heat treatment process. The wrapper's main function is to show that the wrapper is new and has not been tampered with. However, it has come to the attention of the applicant that illegal refillers of LPG bottles are now producing replicas of these wrappers and heat shrinking them onto the caps of the illegally refilled bottles.

It will therefore be appreciated that it is then difficult to determine which bottles have been illegally refilled and which have not. This poses a great danger to the consumer who may inadvertently purchase an illegally refilled cylinder.

It is therefore an object of the present invention to provide a tamper evident cap, and in particular a tamper evident cap for an LPG cylinder, which will indicate that said cylinder has been legitimately filled or refilled to the correct specification, and has not been tampered with thereafter.

The present invention therefore provides a tamperevident cap for use with a valve having a circumferential groove therein, the cap comprising a body having at least one aperture arranged and dimensioned such that, in use, the aperture is in register with the circumferential groove; and a coupling shaped and dimensioned for engagement with the body, the coupling having at least one protrusion which, in use, extends through the aperture and into the circumfrential groove, such as to prevent removal of the body while the coupling is intact, the coupling

being irreversibly removable from the body when it is desired to remove the body from the valve.

Preferably, the body includes a circumferential channel in a side wall thereof, in which channel is located the at least one aperture.

Preferably, the coupling comprises an arcuate portion shaped and dimensioned for engagement within the channel, the at least one protrusion extending radially inwardly from the arcuate portion.

Preferably, the body includes a pair of oppositely disposed apertures in the channel thereof.

Preferably, the coupling includes a pair of oppositely disposed protrusions shaped and dimensioned to extend, in use, through the pair of oppositely disposed apertures.

Preferably, the coupling includes a tab extending from the arcuate portion to facilitate detachment of the coupling from the body.

Preferably, the arcuate portion includes at least one point of relative weakness to allow the arcuate portion to break upon the application of a force to the tab, such as to facilitate detachment of the coupling from the body.

Preferably, the at least one point of relative weakness is a notch located adjacent the tab.

More preferably, there is provided a notch on either side of the tab.

Preferably, the opposed free ends of the arcuate portion are provided with a pair of irreversibly interlocking jaws.

The present invention will now be described with reference to the accompanying drawings, in which; Figure 1 illustrates a perspective view of a body forming part of the cap of the present invention; Figure 2 illustrates an alternative perspective view of the body of Figure 1, showing the internal detail thereof; Figure 3 illustrates a perspective view of a nozzle to which the cap of the present invention may be fitted; Figure 4 illustrates a perspective view of the cap of the present invention; Figure 5 illustrates a perspective view of a coupling which, in use, is secured about the body illustrated in Figure 1; Figure 6 illustrates a perspective view of an alternative embodiment of the coupling of Figure 5; and Figure 7 illustrates a plan view of the coupling of Figure 6.

Referring now to the accompanying drawings, there is illustrated a tamper evident cap, generally indicated as 10, for particular use with conventional liquefied petroleum gas (LPG) bottles (not shown). Such LPG bottles have a nozzle 44 as illustrated in Figure 3 through which, in use, gas is drawn. Similarly, the LPG bottles may be refilled through the nozzle 44. The nozzle 44 includes a circumferential groove 46 disposed externally thereof, as is clearly illustrated in Figure 3. The groove 46 is generally used as a means by which to secure conventional gas operated appliances to the nozzle 44, such as a gas heater (not shown) or the like. The nozzle 44 operates in conventional fashion, and includes a needle 48 located within an annulus 50, depression of the needle 48 permitting the flow of gas through the nozzle 44. With newly filled LPG bottles, or bottles which have been refilled, it is important that the needle 48 be covered, both to prevent damage thereto, and to prevent inadvertent leakage of gas from the nozzle 44. It is also necessary that the means for covering the needle 48 be capable of indicating that the LPG cylinder has been filled or refilled by an authorised, competent filler, for the reasons described above. The nozzle 44 further includes a hexagonal section shoulder 42 which permits the nozzle 44 to be threaded into and out of engagement with an LPG bottle.

The cap 10 includes a body 12 which, in use, is threaded into engagement with the nozzle 44, such as to cover the needle 48. The cap 10 further comprises a coupling 14 which is secured about the body 12 when located on the nozzle 44, the coupling 14 preventing

removal of the body 12 while the coupling 14 is in place, as will be described in greater detail below.

The coupling 14 therefore serves to indicate that the LPG cylinder has been legitimately filled or refilled, and furthermore has not been tampered with thereafter.

Both the body 12 and the coupling 14 are preferably formed from plastic and by any suitable conventional means, such as injection moulding or the like.

The body 12 consists of a top 18, extending from which is a cylindrical side wall 16 which is shaped and dimensioned to provide a contoured fit around the nozzle 44. In designing the cap 10 a major consideration was the compatibility thereof with the existing LPG cylinder valve 44, such as to prevent the necessity of redesigning the valve 44 as well as the conventional cap (not shown). The body 12 is therefore provided with an array of flutes 40 formed integrally with the inner face of the top 18, as illustrated in Figure 2. When the body 12 is placed downwardly over the nozzle 44, the flutes 40 each engage a stud 52 which projects radially inward from the nozzle 44, as is shown in Figure 3. Twisting the body 12 about the nozzle 44 draws each stud 52 into the respective flute 40, such as to draw the body 12 downwardly about the nozzle 44. Disposed between the array of flutes 40 is an insert 38, preferably formed from rubber or similar resiliently deformable material, which abuts against the annulus 50 when the body 12 is fully threaded onto the nozzle 44. The insert 38 prevents gas leaks up to a pressure of 5 bar, in addition to keeping the needle 48 free of any contamination, in order to ensure the

satisfactory operation of the valve 44. Both the flutes 40 and the insert 38 are features which are present on the conventional LPG cylinder cap (not shown) and were carried over when designing the cap 10 such as to permit use thereof with the existing design of valve 44.

The body 12 further includes a circumferentially disposed channel 20 formed in the side wall 18 as shown in Figure 1 of the drawings. The channel 20 is located such that, when the body 12 is threaded onto the nozzle 44, the channel 20 circumscribes the groove 46 formed in the nozzle 44. Extending through the channel 20 to the interior of the body 12 are a pair of oppositely disposed apertures 22. The apertures 22 thus provide access to the groove 46 while the body 12 is secured about the nozzle 44.

As hereinbefore described, the cap 10 includes a coupling 14 which, in use, prevents removal of the body 12 from the nozzle 44, while the coupling 14 is engaged about the body 12. The coupling 14 comprises a split arcuate portion 24, the free ends of which are formed as a pair of inter-engageable jaws 32,34. The arcuate portion 24 is shaped and dimensioned to be seated, in use, within the channel 20. The pair of jaws 32,34 are provided with a plurality of teeth 36 which are arranged to permit the pair of jaws 32,34 to be pressed into engagement with one another, while preventing separation thereof. Thus, the arcuate portion 24 is initially seated within the channel 20, before pressing the pair of jaws 32,34 together such as to lock the coupling 14 within the channel 20. It

will therefore be appreciated that, due to the operation of the pair of jaws 32,34, the coupling 14, once secured in place within the channel 20, cannot be removed therefrom without physically breaking the coupling 14.

It will of course be appreciated that the pair of jaws 32,34, may be replaced by any other suitable alternative, which enables the coupling 14 to be locked about the body 12. One such suitable alternative would be to secure the free ends of the arcuate portion 24 together by means of plastic welding, thereby preventing the separation thereof.

Referring to Figures 3 and 4 of the drawings, it can be seen that the coupling 14 includes a plurality of protrusions 26 which extend radially inwards therefrom.

When locating the coupling 14 within the channel 20, the coupling 14 is oriented such that the protrusions 26 are aligned with the apertures 22 in the channel 20.

Therefore, when the coupling 14 is locked into position within the channel 20, the plurality of protrusions 26 extend through the pair of apertures 22, and are seated within the groove 46 of the valve 44.

It will of course be understood that while the protrusions 26 are located within the groove 46 the body 12 cannot be drawn upwardly out of engagement with the nozzle 44. The only way to enable removal of the body 12 from the valve 44, once the coupling 14 has been secured in place, is to break the coupling 14 from the body 12, thereby clearly indicating that the cap 10 has been tampered with.

In order to facilitate removal of the coupling 14, a tab 28 is provided thereon. The tab 28 projects upwardly from the arcuate portion 24, and effectively acts as a lever by which to twist the arcuate portion 24 such as to effect the breaking thereof. The tab 28 projects upwardly to lie, in use, substantially flush with the side wall 16 of the body 12, in order to prevent damage thereto during transport and/or storage of the LPG bottle. In use, the consumer grips the tab 28 between the forefinger and thumb, and forces the tab 28 downwardly so that the arcuate portion 24 on either side thereof twist and shears to allow removal of the coupling 14. To aid in the shearing of the arcuate portion 24, there are provided a plurality of notches 30 formed therein, such as to act as points of weakness at which the annular portion 24 will break. One such notch 30 is thus positioned on either side of the tab 28.

The body 12 further includes a collar 54 connected thereto by means of a flexible strap 56. Prior to filling or refilling an LPG bottle, the valve 44 is first removed therefrom, and the free end passed through the collar 54 such that the shoulder 42 abuts against the collar 54. The nozzle 44 is then threaded back into engagement with the LPG bottle, thus securing the body 12 to the LPG bottle via the collar 54. The collar 54 is freely rotatable beneath the shoulder 42, and it will therefore be appreciated that the flexible nature of the strap 56 permits the body 12 to be threaded into or out of engagement with the nozzle 44.

In use, once the coupling 14 has been broken away from

the body 12, the strap 56 and shoulder 54 ensure that the body 12 is not separated from the LPG bottle.

Therefore, when the LPG bottle is returned for refilling, it is only necessary to secure a new coupling 14 to the existing body 12 secured thereto.

Referring now to Figure 6 and 7 of the drawings, there is illustrated an alternative embodiment of a coupling, generally indicated as 114, to be secured, in use, about the body 12 as hereinbefore described with reference to the coupling 14. In this alternative embodiment, like features have been accorded like reference numerals, and unless otherwise stated, perform a like function. The only difference with the coupling 114 is that a tab 128 which projects therefrom is, in use, substantially horizontally disposed. It will also be readily understood that any other suitable mechanism may be provided in place of the tab 128, or indeed the tab 28 of the first embodiment, in order to facilitate detachment of the coupling 114,14 from the body 12.

The present invention is not limited to the embodiments described herein, which may be amended or modified without departing from the scope of the present invention.

Claims

CLAIMS 1) A tamper-evident cap for use with a valve having a circumferential groove therein, the cap comprising a body having at least one aperture arranged and dimensioned such that, in use, the aperture is in register with the circumferential groove; and a coupling shaped and dimensioned for engagement with the body, the coupling having at least one protrusion which, in use, extends through the aperture and into the circumfrential groove, such as to prevent removal of the body while the coupling is intact, the coupling being irreversibly removable from the body when it is desired to remove the body from the valve.
2) A cap according to claim 1 wherein the body includes a circumferential channel in the a wall thereof, in which channel is located the at least one aperture.
3) A cap according to claim 1 or 2 wherein the coupling comprises an arcuate portion shaped and dimensioned for engagement within the channel, the at least one protrusion extending radially inwardly from the arcuate portion.
4) A cap according to any preceding claim wherein the body includes a pair of oppositely disposed apertures in the channel thereof.
5) A cap according to claim 4 wherein the coupling includes a pair of oppositely disposed protrusions

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shaped and dimensioned to extend, in use, through the pair of oppositely disposed apertures.
6) A cap according to any of claims 3 to 5 wherein the coupling includes a tab extending from the arcuate portion to facilitate detachment of the coupling from the body.
7) A cap according to any of claims 3 to 6 wherein the arcuate portion includes at least one point of relative weakness to allow the arcuate portion to break upon the application of a force to the tab, such as to facilitate detachment of the coupling from the body.
8) A cap according to claim 7 wherein the at least one point of relative weakness is a notch located adjacent the tab.
9) A cap according to claim 8 wherein there is provided a notch on either side of the tab.
10) A cap according to any of claims 3 to 9 wherein the annular portion is split, with the opposed free ends thereof being provided with a pair of irreversibly interlocking jaws.