GB2130148A

GB2130148A - Seal

Info

Publication number: GB2130148A
Application number: GB08331075A
Authority: GB
Inventors: Frank J Agnelli
Original assignee: EJ Brooks Co
Current assignee: EJ Brooks Co
Priority date: 1982-11-22
Filing date: 1983-11-22
Publication date: 1984-05-31
Also published as: GB8331075D0; GB2130148B

Abstract

A seal 10 for a gas coupling nut or the like comprises two identical housing portions 12, 12a, with cooperating male and female fasteners at their ends. The fasteners comprise a tongue 24 with a latch member 26 receivable in an aperture 30a of the cooperating member 28a. In order to ensure that the seal has not been broken open and replaced, a transparent window portion 38a is provided in the wall of the housing portion, so that a visual check can be made for the presence of the latch portion of the tongue 24. <IMAGE>

Description

SPECIFICATION Seal The invention relates to a seal.

In the gas utility industry, it is often required that provision be made to detect attempts to tamper with gas meters. Such attempts are made either to allow removal of the meter so that a gas blocking plate can be removed or to enable the use of gas directly from the supply pipe. For detection of such attempts, it has been common to enclose the nut which couples the meter pipe to the supply pipe with a seal in the form of two halves which are fastened together with a lead and wire seal, or which are provided with integral means for snapping together in non-removable engagement.

The use of such devices has been limited by the cost thereof, and by the fact that it is often possible to remove such seals and replace them without evidence of tampering.

The invention accordingly provides a seal housing portion arranged for assembly with a cooperating housing portion, the seal housing having spaced fastener members arranged to lock into engagement with spaced fastener members of the co-operating housing portion when the housing portions are assembled to form a seal, with the fastener members within the seal, the seal housing portion having a transparent portion positioned to allow observation of one of the engaged fastener members.

The invention also provides a seal comprising two housing portions having fastener means arranged to non-removably fasten the portions together, the fastener means comprising a pair of locking fastener members, one member of the pair being on each respective housing portion, and one housing portion having a transparent portion through which at least one of the locking fastener members may be viewed.

The invention also provides a seal comprising housing portions having respective fastener means arranged to engage to non-removably fasten the portions together and respective wall means arranged to be received one within the other to enclose the fastener means when nonremovably engaged.

The invention also provides a seal comprising a first housing portion having socket fastener means and a second housing portion having a tongue fastener means arranged to be non-removably received within the socket fastener means, the tongue and socket means each being defined in part by wall means of the respective housing portion.

The seal may be formed in two portions connected by a flexible web, or may be formed of two separate and preferably identical halves. The seal can be made in plastics material and in either case the fastener means can be integrally moulded within the housing portions to allow them to be snapped together into locking nonremovable engagement.

The fastener means, which can comprise a leg or latch with a portion arranged to be resiliently received in an aperture of the co-operating fastener member, are thus enclosed within the seal.

The viewing window where provided is located so that at least a portion of the leg is visible through the window. Tampering with the seal usually results in fracturing of the leg, and its absence can be determined by viewing through the window when the seal is inspected. The seal can be formed of a moulded plastics material of a type which is relatively brittle.

The invention also provides a seal comprising two housing portions having fastener means arranged to non-removably fasten the portions together with the fastened portions capable of limited relative movement.

If the seal has been broken open and then glued together again, relative movement of the housing portions will not normally be possible, so if the parts cannot be so moved tampering of the seal will have taken place. Preferably, the housing portions are sufficiently loose and are of sufficiently brittle material to rattle when tapped.

The seal of the invention can be assembled around a gas meter coupling nut with the seal comprising a ring-shaped member which is generally U-shaped in cross-section so as to enable it to enclose the nut.

For a better understanding of the invention, reference may be made to the following illustrative descriptions and to accompanying drawings, in which: Figure 1 is a plan view of one housing portion of a connection nut seal embodying the invention; Figure 2 is a side view of the housing portion of Figure 1; Figure 3 is a view in section taken on line 3-3 of Figure 1; Figure 4 is a view in section taken on line 4-4 of Figure 1; Figure 5 is a plan view of the housing portion of Figure 1 assembled with an identical housing portion around a connection nut; Figure 6 is a partial sectional plan view of the assembled housing portions of the seal of Figure 5 on a larger scale; Figure 7 is a side view of the assembled housing portions of Figure 6, illustrating the appearance of a viewing window when a locking tongue is in place; and Figure 8 is a view similar to Figure 7 illustrating the appearance of the viewing window when the locking tongue is missing.

The drawings illustrate in Figures 1 to 4, a seal housing portion 12, and in Figures 5 to 8 a connection nut seal 10 which is formed of the housing portion 12 and an identical housing portion 1 2a. The housing portions 12 and 1 2a are thus used in pairs to enclose a coupling nut 13 of a gas meter or the like. In Figures 5 to 8, parts of the housing portion 1 2a corresponding to parts of the portion 12 are given the same reference numerals with the suffix a.

The housing portions are preferably formed of a plastics material which is relatively brittle yet has some limited resilience, for example, polystyrene.

As shown in Figures 1 to 4, the housing portion 12 is generally semi-circuiar in plan and U-shaped in cross-section, with an outer peripheral wall 14 and upper and lower flanges 16 and 18 which extend radially inwardly from the wall. The housing portion has an end 20 with a male fastener and an end 22 with a female fastener.

The male fastener comprises an elongate tongue 24 integral at the rear end with the peripheral housing wall 14 and extending forwardly to project from the end 20, with a latch member 26 disposed near the free end of the tongue. The flexibility of the tongue 24 may be controlled by the provision of an integral web 25 disposed between the rear portion of the tongue and the peripheral wall housing 14. The female fastener at end 22 comprises a forwardly projecting member 28 which is integral with the peripheral wall 14 and has an elongate transverse aperture 30 near the distal end which is positioned to receive the latch member 26a of the housing portion 12a in locking engagement when the two portions 12 and 12a are forced together, as illustrated in Figures 5 to 8.To facilitate such engagement the extreme ends 32 and 34 of the tongue 24 and the members 28 respectively are beveled to provide a camming action to cause sideways flexing of the tongue 24 and the member 28a when the housing portions are forced together, so that the latch member 26 can ride along the member 28a and snap into locking engagement with the elongate aperture 30a. Either or both of the tongue 24 and the member 28 can be resiliently flexible but preferably the member 28 is relatively rigid, being attached to the peripheral wall 14 by side webs 29, between which the tongue 24a passes when the housing portions are assembled. The extreme forward end of the tongue 24a extends beyond the aperture 30 to maximize the area of the member 28 that could be contacted by a tool inserted through a hole from the outside of the assembled housing portions.It will be understood that if desired, the member 28 can be made flexible and the tongue 24 rigid. However, in either case, it is desirable that the flexible member be disposed outside of the non-flexible member to prevent release of the members by provision of a hole in the housing wall 14 to allow a tool to be pushed through to unlatch them.

To assist in preventing access to the fastener member after assembly of the housing portions, the end 22 has an enlarged or cuff portion 36 which is dimensioned to enclose the end 20a of the housing portion 12a when the portions are assembled. The end portion 36 thus overlaps the end 20a so that the tongue 24a and the member 28 are enclosed by the housing portion walls, the end 20a and the tongue 24a being non-removably received within a socket defined by the end portion 36 and the member 28.

The housing portions of the seal may be made of a plastics material which is transparent in a thin section but translucent or opaque in a thicker section. Each housing portion, except for a small portion to be described, then has a thickness such that it is opaque or sufficiently translucent not to be transparent, so that the shape and position of the fastener members cannot be determined from the outside of the housing, other than by way of the small portion.

Attempts to remove such a seal by an unauthorised person will usually result in fracture of the tongue 24. Although after opening the seal by the fracture of a tongue 24, the housing portions may be re-assembled by the use of an adhesive, it is difficult if not impossible to adhere the tongue back to its original position. To allow the absence of a tongue to be detected, a transparent window 38a is provided in the exterior wall 14a at a position opposite the position of the tongue when the seal is assembled. The presence or absence of the tongue 24 may therefore be readily determined by visual examination through the window 38a. When the tongue is present, the window is partially blocked by the end of the tongue, as shown in Figure 7. However when the tongue 24 is missing, substantially the entire aperture 30a is visible through the window as shown in Figure 8.

In another embodiment of the invention, the housing portion may be formed of a material which is inherently transparent, and provided with a surface roughness to render it translucent except in the position of the window 38.

As appears from Figure 6, the housing portions are so shaped and dimensioned that when they are snapped together, there is a space 23 between the upper end of the peripheral wall 14 of the portion 12 and the enlarged portion 36a of the portion 12a, so that the housing portions are capable of small but appreciable amount of relative lateral movement. This enables an inspector to grasp the two housing portions and to relatively move them, to thereby determine that the two portions have not been glued together, in an attempt to disguise the breakage.

Also, a small gap 27 can be provided between the latch member 26 of the housing portion 12 and the edge of the aperture 30a in the member 28a in which the latching member is engaged. The integrity of the seal may then be determined by merely tapping the seal, since the two engaged housing portions 12, 1 2a are loosely enough secured together for the tapping to produce a distinctive rattle-like sound. If the seal had been broken and the housing portions then glued back together, the rattle-like sound would not be produced. For the rattle-like sound to be produced, the housing portions are made of a suitable material for example a brittle material such as styrene rather than a material such as polypropylene.

It will be apparent to one skilled in the art that various modifications may be made in the embodiments described without departing from the scope of the invention as defined by the following claims.

Claims

1. A seal housing portion arranged for assembly with a co-operating housing portion, the seal housing having spaced fastener members arranged to lock into engagement with spaced fastener members of the co-operating housing portion when the housing portions are assembled to form a seal, with the fastener members within the seal, the seal housing portion having a transparent portion positioned to allow observation of one of the engaged fastener members.

2. A seal housing portion as claimed in claim 1 integrally moulded in plastics material the housing portion being opaque or sufficiently translucent for the fastener means not to be visible except through the transparent portion.

3. A seal comprising the seal housing portions claimed in claim 1 assembled with the cooperating housing portion.

4. A seal as claimed in claim 3 wherein the seal housing portion and the co-operating housing portions are identical.

5. A seal comprising two housing portions having fastener means arranged to non-removably fasten the portions together, the fastener means comprising a pair of locking fastener members, one member of the pair being on each respective housing portion, and one housing portion having a transparent portion through which at least one of the locking fastener members may be viewed.

6. A seal as claimed in claim 5 in which the housing portions are hinged together, the fastener members being located at adjacent ends of the housing portions remote from the hinged connection.

7. A seal as claimed in claim 5 in which the fastener means comprises a second pair of fastener members each located on a respective housing portion at a position spaced from the first mentioned fastener member.

8. A seal as claimed in claim 7 in which the housing portions are identical.

9. A seal as claimed in any one of claims 3 to 8 in which one fastener member has an aperture and the other fastener member has latch means arranged to lock in the aperture when the portions are assembled, the aperture being visible through the transparent portion whereby the presence or absence of the fastener member having the latch means may be determined by visual inspection through the transparent portion.

10. A seal as claimed in claim 9 in which the fastener member housing the latch member comprises a flexible tongue.

11. A seal as claimed in any one of claims 3 to 8 in which each housing portion has at least one flexible fastener member.

12. A seal as claimed in claim 11 in which the flexible fastener member may be viewed through the transparent portion.

13. A seal comprising housing portions having fastener means arranged to non-removably fasten the portions together with the fastened portions capable of limited relative movement.

14. A seal as claimed in claim 13 wherein the fastener housing portions are capable of limited lateral movement.

15. A seal as claimed in claim 13 or 14 wherein the fastened housing portions are capable of limited movement toward and away from each other.

16. A seal as claimed in claim 13, or 15 wherein the fastened housing portions are arranged to produce a rattle-like sound when tapped.

17. A seal comprising housing portions having respective means arranged to engage to nonremovably fasten the portions together and respective wall means arranged to be received one within the other to enclose the fastener means when non-removably engaged.

18. A seal comprising a first housing portion having socket fastener means and a second housing portion having a tongue fastener means arranged to be non-removably received within the socket fastener means, the tongue and socket means each being defined in part by wall means of the respective housing portion.

19. A seal as claimed in claim 17 or 18 wherein the wall means are generally U-shaped in crosssection, and the fastener means comprise respective interengageable fastener members extending longitudinally within the wall means.

20. A seal as claimed in claim 17, 18 or 19 wherein one of the members has a latch portion receivable in an aperture of the other of the members.

21. A seal as claimed in any one of claims 17 to 20 wherein each fastener member is formed integrally with the associated wall means.

22. A seal as claimed in any one of claims 17 to 21 wherein the flexibility of at least one of the fastener members is influenced by web means extending between the member and the associated wall means.

23. A seal as claimed in any one of claims 13 to 22 wherein at least one housing portion has a transparent portion positioned to allow observation of one of the fastener means.

24. A seal as claimed in any one of claims 3 to 23 in which the or each housing portion having a transparent portion is integrally formed, the transparent portion being thinner than elsewhere to provide the transparent.

25. A seal as claimed in any one of claims 3 to 23 in which the or each housing portions having a transparent portion is of transparent material internally roughened except over the transparent portion.

26. A seal housing portion substantially as hereinbefore described with reference to Figures 1 to 4 of the accompanying drawings.

27. A seal substantially as hereinbefore described with reference to Figures 5 to 8 of the accompanying drawings.

28. A seal as claimed in any one of claims 3 to 25 and 27 assembled around a pipe coupling nut or the like, the housing portions closely enclosing the nut.