GB2202216A

GB2202216A - Tamperproof bush

Info

Publication number: GB2202216A
Application number: GB08802688A
Authority: GB
Inventors: Cyril George Golding; Eugene Leonowicz
Original assignee: GKN Sankey Ltd
Current assignee: GKN Sankey Ltd
Priority date: 1987-02-04
Filing date: 1988-02-02
Publication date: 1988-09-21
Also published as: GB8702477D0; GB8802688D0

Abstract

A tamperproof bush 10 for insertion in the neck 34 of a beer keg has radial apertures 40 in an upper cylindrical portion 14 of the bush for engagement by extendible/retractable cam actuated pins 54 of a complementary insertion/withdrawal tool 50. Such a bush 10 forms part of a closure assembly including a cover ring 36 also securable within the keg neck. An inclined recess 44 in an upper end face 42 of the bush provides location engagement for a complementary projection 70 on the tool body to ensure alignment of the pins 54 with the apertures 40. An inclined ramp face 46 of the recess 44 ensures that counter-clockwise rotation of the bush is prevented other than by engagement of the pins 54 with the apertures 40. <IMAGE>

Description

TAMPERPROOF BUSH FOR USE IN A BEVERAGE CONTAINER This invention relates to a bush for insertion into the neck of a beverage container, typically a metal beer keg, of the type wherein the bush provides seating and retention means for a valved beverage filling and dispensing mechanism extending into the container The conventional neck of a metal beer keg is provided with a standardised screw thread or bayonet attachment means for receiving a bush and associated valve mechanism, such mechanism typically comprising a down tube extending into the container and associated spring loaded valve means within the bush for controlling the filling or dispensing of beer respectively into or out of the container Hitherto, such a bush has been manufactured by various methods and of various materials and, for example, may comprise a one piece casting or stamping or, as is described in our British Patent 1 577 116, may comprise a two piece assembly having an outer part formed as a casting or stamping and an inner part comprising a stainless steel tubular member.

It has also been proposed to manufacture a bush in two parts from thick walled stainless steel tube and, in our co-pending British patent application 8625830, there is described a two part bush formed from metal pressings of relatively thin wall tubular material.

In all of these bush constructions, it has been conventional practice to insert the bush into the neck of the container and secure it therein either by screwing or by a bayonet attachment. It is also conventional practice to provide two radially inwardly directed diametrically opposed lugs at the, in use, outer face of the bush; such lugs being intended for engagement by a beverage dispensing mechanism but which may also be used for facilitating insertion or withdrawal of the bush relative to the container neck. It will be appreciated that the contents of a beer container are under considerable gaseous pressure and that injury may result if the bush is inadvertently detached from the neck of the container whilst the contents are under pressure.

Solutions to this problem of inadvertent or unauthorised withdrawal of the bush relative to the container neck have included the provision of retainer rings spring located within the neck outwardly of the end face of the bush whereby the bush itself cannot be accessed without prior removal of the retainer ring. However, if such a retainer ring is removed, the bush can then be withdrawn with the consequential potential problem of injury.

Our British Patent 1 577 118 describes and illustrates a bush having an unthreaded exterior, thus providing a universal fitting, which is clampable in position in a container neck by a threaded retainer ring However, such retainer ring may be unscrewed by unauthorised personnel with the consequential potential of immediate ejection of the bush and its valve mechanism, and injury to personnel, if the container is pressurised.

All of the fittings described above also permit of unauthorised theft of the container contents as well as of the potential of injury.

It is an object of the present invention to provide a tamperproof bush for insertion into the neck of a beverage container which can only be inserted and withdrawn relative to the neck by use of a complementary insertion/withdrawal tool. It is a further object of the invention to provide a closure unit including such a tamperproof bush for insertion within the neck of a beverage container and a still further object of the invention is to provide an insertion/withdrawal tool for the tamperproof bush of the invention.

In accordance with the first aspect of the invention there is provided a tamperproof bush insertable within the neck of a beverage container comprising a generally cylindrical body having means for retaining a valve mechanism therein and an annular cylindrical portion for engagement with a said neck whereby, in use, said body of the bush is directed inwardly of the neck into the container and said cylindrical portion of the bush is accessible externally of the container through the neck, and wherein said cylindrical portion has one or more recesses extending radially outwardly from the radially inner wall of said cylindrical portion for -engagement by a cooperating insertion/withdrawal tool for the bush.

Preferably the or each, recess comprises an aperture extending through said annular cylindrical portion of the bush.

The, in use, outer end face of said cylindrical portion of the bush is conveniently provided with a recess for location engagement by a cooperating insertion/withdrawal tool for the bush; said location recess preferably including a ramp face and an abutment face, said abutment face providing means facilitating rotational insertion of the bush into the neck of a container and said ramp face providing means for preventing rotation of the bush relative to the neck in the opposite direction.

In accordance with a further aspect of the invention there is provided a closure assembly for insertion into the neck of a beverage container comprising a tamperproof bush as defined in the preceding paragraphs and an annular cover ring engageable, in use, within a said neck outwardly of the outer end face of the cylindrical portion of the bush, said ring having radially inwardly directed formations for engagement by a beverage dispensing mechanism.

Coveniently the cylindrical portion of the bush is externally screw threaded for engagement with a complementary internal screw thread in the neck of the container and said cover ring is also externally screw threaded for engagement with said internal screw thread in said neck.

In accordance with a still further aspect of the invention there is provided an insertion/withdrawal tool for inserting and withdrawing a bush as defined in the preceding paragraphs into or out of the neck of a container comprising a tool body locatable within the cylindrical portion of the bush and one or more retractable and extendible pins extending radially of said body for engagement with the or each said recess in the cylindrical portion of the bush whereby, when the or each pin is extended into a corresponding said recess, the bush may be rotatably inserted into or withdrawn from the neck of the container by rotation of said tool Prefer ably the tool body includes an axially directed projection engageable with the aforesaid location recess on the outer end face of the cylindrical portion of the bush for angularly locating the tool body relative to the bush.

Preferably the or each said pin of the tool is extendible relative to the tool body by cam actuating means within said body, the or each said pin being resiliently biased from its extended position towards its retracted position.

The tool conveniently includes a spigot extending axially of the tool body for engagement with a valve mechanism within a said bush upon location of said tool within a said cylindrical portion of the bush.

Other features of the invention will become apparent from the following description given herein solely by way of example with reference to the accompanying drawings wherein: Figure 1 is a side cross-sectional view of a closure assembly comprising a tamperproof bush and cover ring secured in the neck of a beverage container; Figure 2 is a side cross-sectional view of a complementary insertion/withdrawal tool for the bush of the closure assembly shown in Figure 1; and Figure 3 is a top plan view of the interior of the tool body of Figure 2 showing the cam actuating means.

A tamper proof bush in accordance with the invention may be formed as a casting, a stamping or a pressing but, for the purposes of this specific embodiment, the bush will be described with reference to its construction as a two part metal pressing similar to that described in our co-pending British patent application 8625830.Thus, referring to Figure 1 of the drawings, the bush 10 comprises a two part metal pressing, preferably of stainless steel, comprising a generally cylindrical pressed metal tubular body 12 and an annular pressed metal cap in the form of a cylindrical portion 14 secured to the body 12. The body is pressed from relatively thin-walled circular cross-sectional tube to define at one end thereof (the outer end) an annular radially outwardly extending lip 16 projecting from a cylindrical portion 18 of relatively short axial length which itself merges through a radius into an annular radially inwardly directed flange portion 20.The body extends from this flange portion 20 to provide an annular radially inwardly extending valve seat 22 comprising a frusto-conical surface, that end thereof remote from the outer end of the bush extending into an annular radially outwardly directed flange 24 of the body. From said flange 24 there extends a skirt portion 26 of cylindrical form having one or more circular apertures 28 formed therein intermediate said radially outwardly directed flange 24 and that end of the body (the inner end) remote from the outer end.

The periphery of the skirt portion 26 at the free end thereof is formed with a plurality of radially inwardly directed depressions 30 comprising formations adapted to cooperate with means for retaining a valved filling/dispensing mechanism within the body with a valve thereof seated on the seat 22 as is further described below.

The cap is also pressed from relatively thin walled circular cross-sectional tube and comprises an annular cylindrical portion 14 and a further annular portion 32 depending therefrom which further portion 32 is of lesser wall thickness than that of said cylindrical portion 14.

The external surface of the cylindrical portion 14 is provided with neck engaging means which may be either a bayonet fitting, or a screw, thread as illustrated, whereby the bush 10 may be secured in engagement within an internally threaded neck 34 of a container. The bush 10 is assembled by radially inwardly deforming, such as by swaging, the free end of the thinner section annular portion 32 of the cap 14 around the radially outwardly extending lip 16 at the outer end of the body 12 to secure the cap to the body Figure 1 of the drawings shows a complete closure assembly located within the neck 34 of a beverage container and comprising the two part bush 10 as hereinbefore described together with a cover ring 36 comprising an annular externally screw threaded ring having two diametrically opposed radially inwardly extending lugs 38 with axially directed surfaces slightly inclined to a plane normal to the longitudinal axis of the ring, said lugs 38,providing bayonet fitting means for -the releasable attachment of a beverage dispensing mechanism thereto.

Also as shown in Figure 1, it will be seen that the annular cylindrical portion 14 of the bush includes four recesses in the form of apertures 40 extending through said cylindrical portion 14 from the radially inner wall thereof for engagement by a complementary insertion/withdrawal tool as will be further described Although four such apertures are described and illustrated herein, it should be appreciated that either more than or less than four such apertures or recesses may be provided.

Also as will be seen from Figure 1 of the drawings, the outer end face 42 of the cylindrical portion 14 of the bush is provided with a recess 44 for location engagement by a complementary insertion/withdrawal tool; said location recess including a ramp face 46 and an abutment face 48 for purposes which will be further described.

The valved filling/dispensing mechanism may be of the known form illustrated in Figure 1 for use in a beer container comprising an outer valve 80 - the gas valve of elastomeric material reinforced by a metal ring 82 and having a cylindrical spigot 84 sealingly received in the upper end of a downtube 86. The downtube is urged upwardly by a coil spring 88 which engages a radial flange 90 on the downtube at its upper end and a washer 92 at the other end. The washer 92 surrounds the downtube 86 to guide it but to allow it to move vertically and is engaged with the depressions 30 at the lower end of the bush0. The spring 88 thus urges the sealing face of the valve 80 into sealing engagement with the internal valve seat 22 of the bush.

A metal valve 94 - the beer valve - is provided with four legs and is guided for movement within the downtube 86 under the action of a further coil spring 96 engaging a valve guide 98 at its upper end and bearing upon a shoulder 100 in the downtube at its lower end. The valve 94 is thus urged upwardly into sealing engagement with an elastomeric valve seat provided by a cooperating internal surface of the cylindrical spigot 84-of the valve 80.

In Figure 1 of the drawings the valve mechanism is shown with both valves 80 and 94 in their closed positions within the closure assembly i.e. the bush 10 and the cover ring 36, and operates in a well known manner. When the closure assembly is engaged by a beverage dispensing mechanism, the valve 94 is opened and the pressurised gas within the container causes liquid to pass up the downtube 86, around the open valve 94 and into the dispensing mechanism. The gas valve 80 is usually only moved off its seat 22 during a container filling cycle when, for example, beer can be passed between the valve 80 and the seat 22 and displace gas out of the container via the downtube 86 and the beer valve 94.

Referring now to Figures 2 and 3 of the drawings there is shown a said complementary insertion/withdrawal tool comprising a tool body 50 in the form of a generally cylindrical housing 52 within which are located four extendible and retractable pins 54 resiliently biased by coil compression springs 56 towards a radially inwardly retracted position, each spring 56 acting between the housing 52 and an enlarged head 58 of a pin 54. Within the housing 52 is an actuating cam 60 rotatable relative to the housing 52 and having four cam faces 62 to effect radially outwardly extension of the pins 54 against their spring loading. The tool body 50 includes a handle 64 secured to an end face of the housing 52 and a spring loaded actuating bar 66 extending through a slot in the housing 52 into engagement with the cam 60 whereby the cam may be rotated within the housing to effect pin extension as previously described. The axial end face of the housing 52 remote from the handle 64 includes a formation 70 having an abutment face 72 and a ramp face 74 complementary to the said location recess 44 on the outer end face 42 of the cylindrical portion 14 of the bush.

The base of the housing 52 includes a central cylindrical spigot 68 for engagement with the top surface of the valve 94.

In use, to insert the tamperproof bush 10 in the neck 34 of a container, it is first of all loosely screwed in and the tool is then engaged with the cylindrical portion 14 of the bush. The pins 54 of the tool are aligned relative to the corresponding apertures 40 in the cylindrical portion 14 of the bush by engaging the said formation 70 on the end face of the tool body within'the location recess 44 in the end face of the cylindrical portion 14; the corresponding abutment faces 72 and 48 respectively of the formation 70 and the recess 44 enabling screw threaded insertion of the bush to be continued into the neck with final tightening being achieved by rotating the cam bar 66 to extend the pins 54 into the corresponding apertures 40 to enhance the driving torque applicable to the bush.Such final tightening brings the radially outwardly directed flange 24 into sealing engagement with an elastomeric O-ring 76 located upon a radially inwardly projecting annular seating 78 provided on the neck 34.

The cover ring 36 is then screwed down into the neck 34 over the bush to the position shown in Figure 1 of the drawings It will be appreciated that the cover ring 36 may be screwed into the neck 34 by means of the lugs 38 to contact the end face 42 of the cylindrical portion 14 of the bush; the ring 36 being tightenable against said end face 42 to achieve a lock nut effect thereby further enhancing the tamperproof capabilities of the closure assembly as a whole.

The above sequence of operations is reversed if the bush 10 is required to be removed from the container neck 34. Firstly the cover ring 36 is unscrewed by a standard type of removal tool which is designed also to open the gas valve 80 thereby venting any pressurised gas in the container to atmosphere. The special tool may then be located within the cylindrical portion 14 of the bush in the manner described above with the pins 54 extended into engagement with the apertures 40. Upon such engagement the spigot 68 depresses the beer valve 94 of the valve mechanism thereby further ensuring that the container interior is vented to atmosphere via the downtube 86.

The bush 10 may then be removed by rotation of the special tool relative to the container neck.

As will be appreciated, although the cover ring 36 may be removed either inadvertently or by an unauthorised operator, the bush itself cannot be unscrewed without use of the complementary insertion/withdrawal tool; The ramp face 46 of the location recess 44 prevents engagement by a tool with said recess for counter-clockwise rotation of the bush relative to the neck, and the bush may only be unscrewed from the neck by insertion of the complementary tool with the pins 54 extended into the corresponding apertures 40. The special tool is engageable with the bush 10 above the valve mechanism whereby there is no possibility of damage to either of the valves 80 or 94 during insertion or removal of the bush. Furthermore, the spigot 68 on the tool ensures venting of the container by depression of the valve 94 during engagement of the tool with the bush.

Claims

1. A tamperproof bush insertable within the neck of a beverage container comprising a generally cylindrical body having means for retaining a valve mechanism therein and an annular cylindrical portion for engagement with a said neck whereby, in use, said body of the bush is directed inwardly of the neck into the container and said cylindrical portion of the bush is accessible externally of the container through the neck, and wherein said cylindrical portion has one or more recesses extending radially outwardly from the radially inner wall of said cylindrical portion for engagement by a cooperating insertion/withdrawal tool for the bush.

2. A bush as claimed in Claim 1 wherein the or each recess comprises an aperture extending through said annular cylindrical portion of the bush.

3. A bush as claimed in either one of Claims 1 or 2 wherein the cylindrical portion is externally screw threaded for engagement with a complementary internal screw thread in the neck of the container.

4. A bush as claimed in any one of Claims 1 to 3 wherein the, in use, outer end face of said cylindrical portion of the bush is provided with a recess for location engagement by a cooperating insertion/withdrawal tool for the bush.

5. A bush as claimed in Claim 4 wherein said location recess includes a ramp face and an abutment face, said abutment face providing means facilitating rotational insertion of the bush into the neck of a container and said ramp face providing means for preventing rotation of the bush relative to the neck in the opposite direction.

6. A closure assembly for insertion into the neck of a beverage container comprising a bush as claimed in any one of Claims 1 to 5 and an annular cover ring engageable, in use, within a said neck outwardly of the outer end face of the cylindrical portion of the bush, said ring having radially inwardly directed formations for engagement by a beverage dispensing mechanism.

7. A closure assembly as claimed in Claim 6 when appendent to Claim 3 wherein said cover ring is externally screw threaded for engagement with a said complementary internal screw thread of the neck of the container.

8. An insertion/withdrawal tool for inserting and withdrawing a bush as claimed in any one of Claims 1 to 5 into or out of the neck of a container comprising a tool body locatable within the cylindrical portion of the bush and one or more retractable and extendible pins extending radially of said body ,for engagement with the or each said recess in the cylindrical portion of the bush whereby, when the or each pin is extended into a corresponding said recess, the bush may be rotatably inserted into or withdrawn from the neck of the container by rotation of said tool.

9. A tool as claimed in Claim 8 for use with a bush as claimed in either one of Claims 4 or 5 wherein said tool body includes an axially directed projection engageable with said location recess in the end face of the cylindrical portion of the bush for angularly locating the tool body relative to the bush.

10. A tool as claimed in either one of Claims 8 or 9 wherein the or each said pin is extendible relative to the tool body by cam actuating means within said body, the or each said pin being resiliently biased from its extended position towards it retracted position.

11. A tool as claimed in any one of Claims 8 to 10 including a spigot extending axially of the tool body for engagement with a valve mechanism within a said bush upon location of said tool within a said cylindrical portion of the bush.

12. A tamperproof bush insertable within the neck of a beverage container constructed and arranged substantially as hereinbefore described with reference to the accompanying drawing.

13. A closure assembly for insertion into the neck of a beverage container constructed and arranged substantially as hereinbefore described with reference to the accompanying drawing.

14 An insertion/withdrawal tool for inserting and withdrawing a bush as claimed in any one of Claims 1 to 5 or 12 into or out of the neck of a beverage container constructed and arranged substantially as hereinbefore described with reference to the accompanying drawing.