IE991007A1

IE991007A1 - Tamper evident seal

Info

Publication number: IE991007A1
Application number: IE991007A
Authority: IE
Inventors: Paul O'connell
Original assignee: Rustsun Ltd
Priority date: 1998-12-01
Filing date: 1999-12-01
Publication date: 2000-07-12

Abstract

A tamper evident seal (1,30) for mounting on a valve of a pressue fuel gas bottle has a cover (6) with an associated retaining tie strap (7) for securing the cover (6) in position across the valve outlet. A tear strip (8) in the cover (6) is operable to release the cover (6) from the valve outlet. <Figure 1>

Description

This invention relates to a tamper evident seal, and in particular to a tamper evident seal for a pressurised fuel gas bottle having a valved outlet.

The invention is particularly concerned with giving tamper indication for pressurised fuel gas bottles of the type having a handwheel operated outlet valve. Such handwheel valves rely on a sealing disc within the valve operated by the handwheel and also on an external sealing cap which is usually hexagonal which is mounted at the outlet of the valve. If a valve sealing disc leaks, the external sealing cap must be able to withstand the maximum cylinder pressure without leakage.

It is an object of the present invention to provide an effective tamper evident seal for such fuel gas bottles.

Statements of Invention According to the invention, there is provided a tamper evident seal for a pressurised —s fuel gas bottle having a discharge valve with a valve outlet, the tamper evident seal comprising a cover having an end wall with an outwardly extending skirt projecting outwardly from an inside face of the end wall to define therewith a housing for reception of the valve outlet, the cover having a tear strip formed in the skirt and end wall defined by a pair of spaced-apart tear grooves extending through the skirt and end wall to reduce the wall thickness and having a pull tab at one end of the tear strip, a tie strap mounted on the cover for engagement about the discharge valve to retain the cover over the valve outlet, complementary inter-locking formations being provided on the tie strap and on an associated catch mounted on the cover for interlocking engagement of the tie strap and catch. Advantageously, when the fuel gas bottle has been filled, the tamper evident seal can be readily easily and quickly mounted across the outlet to give indication of any unauthorised use of the fuel gas bottle. The seal is easily and quickly removed by pulling away the tear strip which releases the cover allowing access to the valve outlet.

INT - 2 IE 991007 In one embodiment of the invention the tie strap has a neck portion of reduced width intermediate the ends of the tie strap.

In another embodiment the tie strap projects outwardly at opposite sides of the skirt of the cover with the catch being mounted at a free end of one strap portion, a free end of the other strap portion being engagable with the catch.

In a further embodiment the strap portions are off-set at an obtuse angle to each 10 other. ; ---X Preferably the catch has a body with a slot for reception and through-passage of the tie strap with a first set of serrations being provided on one wall of the slot for interlocking engagement with a complementary second set of serrations on an associated mating face of the strap, the serrations being arranged to allow the strap be drawn through the slot in one direction only for locking engagement of the strap with the catch. in another embodiment a grip tab is provided on the catch body projecting outwardly 0 from an exterior of the catch body.

In a further embodiment a recess is provided in the slot of the catch body opposite the serrations, an associated locking projection extending outwardly of a face of the strap to the serrated face for engagement within the recess.

In another embodiment the locking projection is a ramp having an inclined leading face terminating in a trailing face which projects outwardly of the face of the strap for engagement with an end wall of the recess.

In a further embodiment a stop bar is mounted on the strap spaced-apart from the locking projection for engagement against an outside of the catch body when the ramp locates in the recess.

Preferably the stop bar has an arcuate engagement face for complementary - 3 engagement with an arcuate outside face of the catch body adjacent the slot.

In another embodiment a number of spaced-apart ramps are provided on the face of the strap opposite to the serrated face.

In another embodiment the catch is mounted on an outer face of the skirt.

Ideally the pull tab incorporates a ring pull.

Most preferably the strap is integrally formed with the cover.

In a preferred embodiment, the cover has a generally cylindrical body closed at an outer end, an inner end of the body being open for reception of the valve outlet.

The tamper evident seal is most preferably of moulded plastics material.

Detailed Description of the Invention The invention will be more clearly understood by the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which:Fig. 1 is a plan view of a tamper evident seal according to the invention; Fig. 2 is a sectional view taken along the line ll-ll of Fig. 1; Fig. 3 is an elevational view of the tamper evident seal in use mounted on a handwheel valve of a pressurised fuel gas bottle; Fig. 4 is a view similar to Fig. 1 of another tamper evidence seal; Fig. 5 is an elevational view of the tamper evident seal shown in Fig. 4; Fig. 6 is a detail sectional view showing a catch of the tamper evident seal; - 4 and Fig. 7 is a detail underneath plan view showing portion of a tie strap of the tamper evident seal.

Referring to the drawings and initially to Figs. 1 to 3 thereof, thereis illustrated a moulded plastics tamper evident seal according to the invention, indicated generally by the reference numeral 1. The seal 1 is for mounting on a handwheel valve 2 of a pressurised fuel gas bottle 3, said handwheel valve 2 having an outlet 4 which is normally covered by a pressure retaining sealing cap 5 which screws onto the outlet 4.

The tamper evident seal 1 has a cover 6 for engagement about the valve outlet 4 and cap 5 with a retaining tie strap 7 for securing the cover 6 in position across the valve outlet 4. A tear strip 8 in the cover 6 is operable to release the cover 6 from the valve outlet 4.

The cover 6 has a generally cylindrical skirt body 10 having a closed outer end wall 11. An inner end 12 of the cover 6 is open for reception of the valve outlet 4 and cap •-X .

The tear strip 8 is provided in the cover 6 and is defined by a pair of spaced-apart grooves 14. These grooves 14 form weakened portions in the cover 6. The grooves 14 extend along a side wall of the skirt body 10 and across the outer end wall 11 of the cover 6. At one end of the tear strip 8, a ring puli 16 is provided to assist in tearing away the strip 8.

The tie strap 7 is integrally formed with the cover 6, the strap 7 having a catch 20 at one end, engagable with associated interlocking formations, in this case comprising teeth 22 on the other end of the strap 7. These teeth 22 are engagable with and interlock with associated teeth 23 within a slot 24 of the buckle 20 so that the cover 6 can be securely locked about the valve 2- It will be noted that both portions of the strap 7 extend outwardly at an obtuse angle relative to each other on each side of the cover 6 and this facilitates neatly mounting the tie strap 7 about the valve 2 as shown - 5 IE 991007 in Fig. 3.

In use, when the gas bottle 3 has been filled, the tamper evident seal 1 is mounted with the cover 16 over the valve outlet 4 and pressure retaining cap 5 and the tie strap 7 is engaged about the valve 2 to secure the cover 6 in position as shown in Fig. 3. To use the gas bottle 3, the tamper evident seal 1 must be removed. A user grips the ring pull 16 and pulls away the tear strip 8 to release the cover 6 from the valve 2. It will be appreciated that the tamper evident seal 1 prevents unauthorised use of the bottle 3 as any such unauthorised use will be immediately evident due to damage to the seal 1 which must occur if the cover 6 is removed fromthe valve 2.

Referring now to Figs. 4 to 7 there is illustrated another tamper evident seal indicated generally by the reference numeral 30. Parts similar to those described previously are assigned the same reference numerals. In this case the tie strap 7 has a neck portion 31 of reduced width intermediate the ends of the tie strap 7. This forms a weakness in the tie strap 7 such that if an attempt is made to prise the seal 30 off the valve without removing the tear strip 8, then the strap 7 will shear to give indication of tampering.

The catch 20 is shown in more detail in Fig. 6. The catch 20 having a body with a slot 33 for reception of and through passage of the tie strap 7. The serrated teeth 23 are provided on a roof wall of the slot 33 for engagement with the complementary serrated teeth 22 on the tie strap 7. As previously described the serrations are arranged to allow the strap 7 to be drawn through the slot in one direction only for locking engagement of the strap 7 with the catch 20. A grip tab 35 is provided on the catch body projecting upwardly for securely holding the catch body 2 while the strap 7 is drawn through the slot 33. It will be noted that a recess 36 is provided in the slot 33 of the catch 20 opposite the teeth 23. An associated locking ramp 38 is provided on a face of the strap 7 opposite the teeth 22. Thus, when the strap 7 engages in the slot 33, the ramp 38 engages within the recess 36 to further lock the strap 7 in engagement with the catch 20. The ramp 38 has an inclined leading face 39 terminating in a trailing face 40 which projects outwardly of the face 41 of the strap 7 for engagement with an end wall 42 of the recess 36. An arcuate stop bar 45 is mounted on the strap 7 spaced-apart from the ramp 38 for engagement against an arcuate outside face 47 of the catch body 20 when the ramp 38 locates in the recess 36. This provides additional security and prevents over-tightening of the strap 7 which might inadvertently break the strap at the narrowed neck portion 31. It also allows a free end of the strap 7 to be broken away after it has been drawn through the slot 33. As can be seen in this case a second ramp 49 is also provided on the strap 7 spaced-apart from the first ramp 38 to accommodate valve constructions of different dimensions.

The invention is not limited to the embodiments hereinbefore described which may be 10 varied in both construction and detail.

Claims

1. A tamper evident seal for a pressurised fuel gas bottle having a discharge valve with a valve outlet, the tamper evident seal comprising a cover having

2. A seal as claimed in claim 1 wherein the tie strap has a neck portion of reduced width intermediate the ends of the tie strap.

3. A seal as claimed in claim 1 or claim 2 wherein the tie strap projects outwardly at opposite sides of the skirt of the cover with the catch being mounted at a 20 free end of one strap portion, a free end of the other strap portion being engagable with the catch.

4. A seal as claimed in claim 3 wherein the strap portions are off-set at an obtuse angle to each other.

5. A seal as claimed in any preceding claim wherein the catch has a body with a slot for reception and through-passage of the tie strap with a first set of serrations being provided on one wall of the slot for inter-locking engagement with a complementary second set of serrations on an associated mating face 30 of the strap, the serrations being arranged to allow the strap be drawn through the slot in one direction only for locking engagement of the strap with the catch. 5 an end wall with an outwardly extending skirt projecting outwardly from an inside face of the end wall to define therewith a housing for reception of the valve outlet, the cover having a tear strip formed in the skirt and end wall defined by a pair of spaced-apart tear grooves extending through the skirt and end wall to reduce the wall thickness and having a pull tab at one end of the 10 tear strip, a tie strap mounted on the cover for engagement about the discharge valve to retain the cover over the valve outlet, complementary interlocking formations being provided on the tie strap and on an associated catch mounted on the cover for inter-locking engagement of the tie strap and catch. 15

6. A seal as claimed in claim 5 wherein a grip tab is provided on the catch body IE 9&1007

7. A seal as claimed in claim 5 or claim 6 wherein a recess is provided in the slot of the catch body opposite the serrations, an associated locking projection extending outwardly of a face of the strap to the serrated face for engagement within the recess.

8. A seal as claimed in claim 7 wherein the locking projection is a ramp having an inclined leading face terminating in a trailing face which projects outwardly . of the face of the strap for engagement with an end wall of the recess. 9. A seal as claimed in claim 7 or claim 8 wherein a stop bar is mounted on the strap spaced-apart from the locking projection for engagement against an outside of the catch body when the ramp locates in the recess. 10. A seal as claimed in claim 9 wherein the stop bar has an arcuate engagement face for complementary engagement with an arcuate outside face of the catch body adjacent the slot. 11. A seal as claimed in any of claims 8 to 10 wherein a number of spaced-apart ramps are provided on the face of the strap opposite to the serrated face. 12. A seal as claimed in claim 1 or claim 2 wherein the catch is mounted on an outer face of the skirt. 13. A seal as claimed in any preceding claim wherein the pull tab incorporates a ring pull. 14. A seal as claimed in any preceding claim wherein the strap and catch are integrally formed with the cover. 15. A seal as claimed in any preceding claim wherein the seal is of moulded plastics material. - 8 projecting outwardly from an exterior of the catch body.

9. - 9 16. A tamper evident seal substantially as described herein with reference to the accompanying drawings.