US2938643A - Closure - Google Patents

Description

y 1960 M. L. GEISER ET AL 2,938,643

CLOSURE Filed Oct. 15, 1956 \4 /7' I INVENTOR 9 :j 11 6 a MILTON L. nausea v seems L. HERR United States Patent 1 2,938,643 CLOSURE Milton L. Geiser, Manor Township, and George L. Herr,

West Lampeter Township, Lancaster County, Pa., assignors to Armstrong Cork Company, Lancaster, Pa., a corporation of Pennsylvania Filed Oct. 15, 1956, Ser. No. 616,092 1 Claim. (Cl. 217-98) This invention relates to a bung, and more particularly to an elastomeric bung to replace the cork bung for insertion in the bung bushing of a barrel.

The conventional tap bungs for barrels containing beer, ale, and the like have been made from cork; however, due to recent economic conditions cork has become relatively expensive for this purpose, and also with the development of certain synthetic plastic products suitable substitutes for cork have been developed for most uses.

In order for a bung to function properly for this purpose, it is necessary that it be designed so that it can be driven easily into the bung bushing with existing driving equipment, will be held securely in position in the bung bushing to prevent the pressure developed in the keg from blowing the bung out of its sealing position, and also can be driven on through the bung bushing into the keg when the tap pump is inserted to remove the beer from the keg. Due to the fact that it must be driven into the keg and also due to the fact that the interior of the bung is in engagement with the contents of the keg, it is essential that the bong be produced from materials which will not have a toxic or other deleterious effect on the contents of the keg.

Several attempts have been made to produce bungs from plastic material such as polyethylene, and the general trend has been toward a bung which forms a seal by providing a continuous ledge around the bottom edge of the bung which is exerted against the shoulder or bottom surface of the bung bushing. In order to insure'this seal, it is necessary to have a rather heavily reinforced bottom edge on the skirt of the bung which is usually deformed during the insertion of the bung into the keg, which deformation impairs the sealing characteristics of the bung. When this reinforcing ring is compressed during insertion, there is no space provided into which the compressed material can be distributed. Because of this material distribution, the bottom skirt either develops a fold or the reinforced ring assumes an oval shape in the opening in the bung bushing. In the case of the fold, the material forming the bung is usually ruptured, resulting in an improper seal; and in the case of the assumed oval, the bung is cocked in the bushing to such an extent that the top edge of the opening in the bushing gouges sections from the side of the hung. in either instance the sealing qualities of the bung are greatly impaired.

Other plastic bungs have been developed having a scrim of ribs around the skirt of the bung, giving line contact between the bung and the bushing at several points in the bushing. This line contact has not been satisfactory due to the fact that bushings through reuse become scored on their inner or sealing surface. With these score marks, it is not easy to seal the contents of the barrel with a polyethylene bung having several line contact points throughout the depth of the bung. In structures having a plurality of sealing rings around the skirt of the bung, these rings are of necessity of such nature that they serve as reinforcing rings and prevent the expansion of the bung to permit the wall of the bung to be urged against the bushing by the internal pressure on the bung. Here again, with a plurality of reinforcing rings surrounding the bung, there is no opportunity for the material in the rings to be redistributed; therefore, the ring tries to assume an oval shape and in so doing cocks the hung in the opening in the bushing, causing areas near the top'ofthebushing to be gouged.

Keeping in mind the limitations of the existingbung's, the hollow, cup-shaped bung of this invention was 'developed to be easily inserted without deformation 'of "the bottom of the cylindrical skirt and without cocking of the bung in the opening of thebun'g bushing, leaving a relatively large area of the skirt of the bung for sealing engagement with the internal surface of the bushing, and at the same time provide suitably reinforced rings for sealing score marks in the bung bushing.

In order that our invention may be more readily understood, it will be described in connection with the attached drawing, in which:

Figure l is an elevat-ional view of the bung;

Figure 2 is a cross sectional 'view of the bung taken on the line Illl of Figure 3;

Figure 3 is a plan view looking at the bottom of the bung;

Figure 4 is a sectional view of a bung bushing showing the position of the bung in sealing engagement therewith; and

Figure 5 is a view similar to Figure 4 showing a modified form of bung bushing.

Referring to Figure 1, there is shown a hung designated generally by the numeral 2 having a relatively flat top portion 3 for engagement by driving means to insert the bung in the bushing and to remove it therefrom. The bung 2 has a relatively thin depending skirt .portion 4 terminating in a beveled lip 5 having a diameter slightly less than the diameter of the bung opening in the bushing into which the bung is to be driven. The bottom bfthe bung 2 is open for the admission of gaseous pressure into the bung cavity. Located adjacent the beveled portion of the bung are a plurality of locking lobes 6. These locking lobes 6 are so spaced around the periphery of the skirt as to leave areas 7 positioned therebetween which are of relatively thin wall thickness. The purpose ofv the lobes 6 is to lock the bung firmly in engagement with the bushing 3 (Figures 4 and 5) by means of the flat surface 9 on the top of the lobe disposed angularly from the skirt of the bung, engaging the underneath surface of the bushing. The top surfaces of all the lobes'6 are fiat and are disposed on substantially the same horizontal plane. The outer surface of the body of the lobes is tapered from the outer edge of the top surface 9 to the line where it blends into the skirt of the bung near its lower extremity. This tapered design in the area 10 facilitates inserting the bung into the bushing -8. The lobes 6 are also arcu'ate in a plane normal to the longitudinal axis of the bung, resulting in a lobe configuration in which the lobe gradually blends into the surface of the skirt at all points except those lying on the line where the top surface 9 joins the skirt of the bung. The line at which the lobe blends into the skirt of the bung is designated by the numeral 11. With this'design, when the bung is driven into'the bushing, the elastomeric material of which the lobe is comprised can be redistributed temporarily during the driving operation into the area between lobes so that the bottom skirt of the bung is not deformed during the inserting operation. With the arcuate design as here disclosed (Figure 3) there are no sharp angles presentto offer resistance to the redistribution of the elastomeric material during this driving operation. The resistance to redistribution caused by sharp angles results in pieces being broken oif the edges of the elastomeric piece. This tendency to break under compression is practically eliminated by this design. With a structure of this type, the bottom skirt of the bung has engaging means for engaging the bushing to lock the hung in sealing position,- but at the same time there is no continuous reinforcing rib around the lower extremityof the bung to prevent the gaseous pressure exerted on the interior of the bung from expanding the bung into firm sealing engagement with the sides of the bushing. This is a highly desirable feature 7 because the lobes bythis specific design'furnish two functionsone,. holding the bung in position; and second, l holding the bottom skirt of the hung in proper shape but jat the same time permitting therelatively thin side wall to expand due to the internal pressure exerted, forcing the bung against the bushing 'over a large area throughout substantially the entire depth'of the hung in the bushing. The seal effected between the smooth sides of the bung with the bushing is satisfactory-withunmarred bushings; however, careless insert-ion of the tap rod in the bushing results in scoring the side of the bushing to, such an extent that the elastomeric material of the side wall of the bung will not distribute itself into the score" marks and the top portion ofthe bung but a heavily reinforced area 17 on either side leading over toward the depending skirt. The purpose of this reinforced area 17 is to impart to the bung sufiicient strength'to'prevent thetap rod, which is used to push the bunglinto' tlie barrel, from puncturing thetop surface but instead the'lrod engages the hung in Y a relatively wide area over the heavily reinforced portion and pushes the entire bung into the barrel. This is a highly desirable feature, inasmuch as the bung is completely removed from the bushingand can be taken out of the barrel in one 'piece after the contents have been tapped therefrom. Another reason for this heavily reinforced area 17 is that expressed earlier in connection with the sealing ring 13 wherein the mass of material -17 acts I 'formity with' the formation of the opening in the bushing.

seal the score marks. In order to insure a proper seal in those instances where score marks are present on the inner surface of the bushing, there are included on the bung here under consideration two sealing rings 12 and 13. The positioning'ofthese sealing rings'is such'that a major portion of the smooth surface ofthe bung is exposed between the locking means 6 and the first sealing ring 12 to allowample sealing surface for unmarred bushings. Also this ring 12 is so positioned as not to 'restrict the expansion of the lower portion of the skirt of the bung.

" i The sealing ring 12 may be referred to as asemi-stifi fsealing ring. It is triangular in cross section, having a flat top surface and a beveled side extending from the outer'extremity of the flat ledge to the line where it blends into the body of the bung. In juxtaposition to the ring 12 is a reinforcing ring 14 on the inner surface of the bung. With this'structure it will be obvious that the elastomeric material of the ring 12 is forced into any score'lines'or other irregularities in the bushing by means '"of'theispring action of the barrel section of the bung further-supported by the inside reinforcing ring 14. As the'bung is driven into the bushing, the ring 12 is squeezed j a I tween the bushing and the bung and assumes a flattened out configuration. f

The ring -12 does not cause cocking of the bung during the insertion of the bung into the bushing because the ring 12 itself does not have suificient strength to resist deformation, and the reinforcing member 14 which backs up'the ring 12 is of a diameter less than the diameter of the bushing and, therefore, does not offer the resistance.

a We have found polyethylene particularly well adapted for the purpose of carrying out this invention; however, any elastomeric material capable of deformation under the pressures used in inserting articles of this type is suitable, provided, of course, the material is so selected as not to deleteriously aflfect the contents of the barrel.

It will be obvious to those skilled in the art that the plastic bung herein described is of such construction. that it may be easily driven into a tap bushing without deforming the lower skirt of the bung, leaving a relatively large area of the skirt of the bung for sealing engagement with the tap bushing. The bung is also provided with auxiliary sealing means to seal against any deformities which may be present inthe interior surface of the bushing.

We claim: v 7

A cup-shaped bung for insertion into the bung bushing of a barrel, said bung comprising a relatively heavy top said cylindrical skirt, the diameter of the terminal edge of the beveled portion being less than the diameter of the opening in the bushing, the flexible skirt of said bung being capable of expansion under. pressure to form a tight seal between the bung and the bushing, a plurality of angularly projecting lobes disposed on thebeveled'portion 'of the skirt to engage the under portion of the bushing the bushing, said lobesextending from the top of said beveled portion throughout substantially the entire depth thereof, the outer surface of said lobes tapering from the outer edges of said fiat top portions to the lower portions -material of the ring to conform to the deformation and form a seal. The ring 13 is so positioned that when it enters the opening in the bushing substantially the entire body of the bung is in the bushing and cocking of the bung is'thereby prevented. This resistance to cocking also aids in forcing the sealing ring 13 into any deformitiesinthe bushing. V

From a study of Figure 5, it will be observed that sealing rings 12 and 13 are so positioned that when used in bushings having the cork lock groove 15 one of the sealing rings is located below the groove and the other is located above. It is, therefore, immediately apparent that all of 'the sealing features of this bung function on bushings having'the cork lock groove as well as on smooth bore bushings. i

The hollow cavity in the bung is arch-shaped as shown at 16, resulting in a relatively thin wall, in the center of or said lobes, said lobes being spaced from one another by segments of said beveled portion, an outward circumferential projection in the sealing zone between the top section and the flexible depending skirt, andan inner reinforcing ring in juxtaposition to said outward projection. a 7 I References Cited in'the file of this patent UNITED STATES PATENTS -mm- W he may

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