GB2315485A - Bung and bush for sealing a shive hole - Google Patents

Abstract

Means for sealing a shive hole (4, figure 1) comprises a bung 20 in combination with a bush 2, in which the bung and bush are dimensioned so that when the bung is driven into the bush, the bush deforms to fill any gaps between said shive hole and said bush. The bush may have a flange 14 and a rib 18 to maintain it in the hole. The bung may have a flange 34 to seat against the flange on the bush, or may be shaped so that it may be driven flush with the top of the bush (figure 3). The bush and bung are preferably moulded in one piece with the bung aligned with the hole in the bush and connected by one or more webs (36, figure 9) which break when the bung is driven into the bush. The bush and bung may also have complementary ribs 26 and 28 to help to retain them in the shive hole.

Description

BUNG This invention relates to bungs.

In one application, bungs are used to seal the shive and tap holes of beer barrels or casks. Both the terms "barrels" and "casks" are used generally, without reference to their capacity. The holes generally have metal walls for durability and with the intention of presenting a smooth surface to which the bungs can seal. In practice the walls become damaged, e.g. during the extraction of the shive when the barrel or cask has been emptied. A particular instance of such damage results from the extraction of wooden shives since these are often prised out with a sharpish instrument.

A shive is known from GB-B-2 268 482 which has a deformable outer sleeve.

The invention is based on a novel recognition that driving the shive with its deformable sleeve into the shive hole as a unit damages the sleeve if there are any protuberances in the walls of the shive hole, and the deformable sleeve does not expand into any cavities in the walls.

Against this background, in accordance with the invention, there is provided a bung for a hole, in combination with a bush, the outside dimensions of the ,bung1 and the inside dimensions of the bush, being such that when the bung is driven into the bush, the bush deforms to seal the bung in the hole.

The bush may be a range of fits in the hole. If it were a somewhat loose fit, that could be accommodated by ensuring that the bung expands it sufficiently against and into any cavities in the walls of the hole. If at the cther extreme the bush is an interference fit in the shive hole so that damage may result from any protuberances in the walls of the shive hole, driving the shive in to deform the bush will expand the bush around any protuberances and, again, fill any cavities.

In a most preferred embodiment, the bush has a generally tapered passage into which the bung is driven, in use, and/or the bung is generally tapered.

Preferably, the bush has an rib positioned to retain the bush in the hole.

The bush and the bung are preferably formed with complimentary ribs so as to reduce any risk that the shive blows out under pressure in the barrel or cask.

A suitable material for the bush is low density linear polyethylene, preferably melt 2 to 10.

A suitable material for the bung is polypropylene, preferably melt 4 to 15.

The bung may include a flange to seat against the flange on the bush. This may allow the bung to be extracted separately from the bush so that the bush may be used several times.

Alternatively the bung may be so shaped that it may be driven flush with the top of the bush, thus presenting less of a protuberance in use and using rather less material in its manufacture.

In one greatly preferred embodiment, the bung and the bush are moulded in one piece, the bung being aligned with the hole in the bush and joined to the bush by one or more webs of such thickness as to break when the bung is driven into the bush. This arrangement is extremely convenient to use and requires only one mould as opposed to two saving greatly on tooling costs.

The invention extends to a beer barrel having the combination fitted to a shive hole and/or a tap hole.

The invention also extends to a method of sealing a hole, comprising placing a bush in the hole and driving a bung into the bush, so deforming the bush to form a seal between the bung and the walls of the hole.

Embodiments of the invention will now be described with reference to the accompanying drawings, in which: Figure 1 is a cross-section through a shive hole of a beer barrel or cask in which is installed the bush of a shive embodying the invention; Figure 2 is a cross section of one example of a shive which embodies the invention, installed in the bush of Figure 1; Figure 3 is a cross section of another shive which embodies the invention, installed in the bush of Figure 1; Figure 4 is a side view, partly in cross section of another shive and bush embodying the invention; Figure 5 is a plan of the shive and bush of Figure 4 from the left of Figure 4; Figure 6 is a plan of the shive and bush of Figure 6 from the right of Figure 4; Figure 7 is a side view, partly in cross section of another bung and bush embodying the invention for the tap hole of a beer barrel; Figure 8 is a plan view of the bung and bush of Figure 7 from the right of Figure 7; and Figure 9 is a detail partly in cross section of the bung and bush of Figure 7.

Referring to Figures 1 to 3 of the drawings, a moulded plastics bush 2 is installed in the shive hole 4 of a beer barrel 6. The walls 8 of the shive hole are uneven through having been scored by prying out wooded shives, for example. The bush has an outer generally cylindrical surface 10 which is dimensioned to fit within a standard sized shive hole. Ribs 12 make the bush a slight interference fit in the shive hole. A flange 14 prevents the bush from being accidentally pushed right through. A rib 18 is provided to retain the bush.

A moulded plastics shive 20 is shown in Figure 2, driven fully home into the bush 2. The shive has a tapered leading section 22 intended to facilitate insertion into the bush. The shive has a generally cylindrical section 24 of such diameter as to deform the bush 2 sufficiently to form a seal between the shive and the walls of the shive hole.

There is sufficient deformation to ensure that the bush fits tightly against the irregular surface of the shive hole around any protuberances and into any cavities therein. The inside of the bush and the outer surface of the shive are provided with complimentary ribs 26 and 28 to resist any tendency of for pressure in the barrel to blow the shive out. As is conventional, the shive has central aperture 30 closed by a thin transverse wall 32 which may be separated or ruptured for insertion of pipes or spiles.

In this embodiment, the shive is formed with a bush 34 which seats against the flange 14 of the bush. One function of the flange 34 is to prevent the shive from being driven through the bush into the barrel.

When the contents of the barrel are spent, the shive and its bush can be removed as a unit by grasping the flange 14 of the bush with a three claw extractor, e.g of the John Bold type. Alternatively, by grasping the flange 34, the shive can be removed leaving the bush in place. The bush may be used several times.

In an alternative arrangement shown in Figure 3, the shive has no flange and is driven in until flush with the top of the flange 14. Advantages of this arrangement are that the shive projects less and less material is used than in the arrangement shown in Figure 2. However there is a potential problem in that it is possible to drive the shive right through the bush if the mallet unintentionally forms a seal across the aperture 30 (not shown in Figure 3). To guard against this possibility mallets, especially rubber mallets should be formed with grooves across their heads.

The shive could be removed without the bush by passing an extractor tool through the aperture 30.

The material of the bush is relatively deformable compared to that of the shive. A suitable material for the bush is low density linear polyethylene, preferably melt 2 to 10.

A suitable material for the shive is polypropylene, preferably melt 4 to 15.

Referring now to Figures 4, 5 and 6, an arrangement is shown in which the shive 20 is moulded in one piece with the bush 2. The two are joined by a thin web 36, the shive 20 being aligned with the hole 4 in the bush. The shive and bush are moulded in one operation saving on tooling costs since only one mould is required. The arrangement is very convenient to use.

The shive and the bush may be made from the same material, e.g. low density linear polyethylene, preferably melt 2 to 10. In that case ribs 38 heavily reinforce the shive so that it is sufficiently rigid to deform the bush.

Alternatively or additionally, the shive may be made from a less deformable material, e.g. polypropylene, preferably melt 4 to 15. In that case the combination of shive and bush is moulded in a double barrel plastics injection moulding machine.

Referring to Figures 7, 8 and 9, a bung 40 and bush 42 are shown of dimensions suitable for the tap hole of a beer barrel. In this version, the bung and bush are made from different materials in one moulding step in a double barrel plastics injection moulding machine. The bush is made from low density linear polyethylene, preferably melt 2 to 10. The bung is made from polypropylene, preferably melt 4 to 15. Being also smaller than the shive, it may be possible to make the bung without reinforcing ribs, as shown. If the bung and the bush are made from the same low density linear polypropylene, it may be necessary to reinforce the bung similarly to the shive 20 of previous Figures. The reinforcing ribs may also be necessary if the pressure in the barrel is high.

Claims (1)

1. A bung for a hole, in combination with a bush, the outside dimensions of the bung, and the inside dimensions of the bush, being such that when the bung is driven into the bush, the bush deforms to seal the bung in the hole.

2. A combination as claimed in claim 1, wherein the bush has a flange to prevent the it from passing through the hole.

3. A combination as claimed in claim 1 or 2, wherein the bush has a generally tapered passage into which the bung is driven, in use, and/or the bung is generally tapered.

4. A combination as claimed in any preceding, in which the bush has a rib positioned to retain the bush in the bung hole.

5. A combination as claimed in any preceding claim, wherein the bush and the bung are formed with complimentary ribs.

6. A combination as claimed in any preceding claim, wherein the bush is made from low density linear polyethylene.

7. A combination as claimed in claim 6, wherein the low density polyethylene is melt 2 to 10.

8. A combination as claimed in any preceding claim, wherein the bung is made from polypropylene.

9. A combination as claimed in claim 8, wherein the polypropylene is melt 4 to 15.

10. A combination as claimed in any preceding claim, including a flange to seat against the flange on the bush.

11. A combination as claimed in any of claims 1 to 9, in which the bung is so shaped that it may be driven flush with the top of the bush.

12. A combination as claimed in any preceding claim, wherein the bung and the bush are moulded in one piece, the bung being aligned with the hole in the bush and joined to the bush by one or more webs of such thickness as to break when the bung is driven into the bush.

13. A beer barrel having a combination as claimed in any preceding claim fitted to a shive hole and/or a tap hole.

15. A method of sealing a hole, comprising placing a bush in the hole and driving a bung into the bush, so deforming the bush to form a seal between the bung and the walls of the hole.