US2765600A - Closure of bottles and like containers - Google Patents

Description

Oct. 9, 1956 S. D. YOUNG 2,765,690

CLOSURE OF BOTTLES AND LIKE CONTAINERS Filed NOV. 15, 1954 5 Sheets-Sheet 1 Oct. 9, 1956 s. D. YOUNG CLOSURE OF BOTTLES AND LIKE CONTAINERS Filed Nov. 15, 1954 s Shets-Shee'r. 2

@ct 1 s. D. YOUNG 2,765,600

CLOSURE OF BOTTLES AND LIKE CONTAINERS Filed NOV- 15, 1954 5 Sheets-Sheet 3 2,7 65,600 CLO URE 6F BQTTLES AND LIKE CONTAINERS Samuel Davison Young, Rugby, England, assignor to Thomas Hunter Limited, Rugby, England Application November 15, 1954, Serial No. 468,936

llaiins priority, application Great Britain November 23, 1953 2 Claims. (Cl. 53-42) This invention relates to the closure of bottles, jars and like containers, especially glass containers, of the kind which are formed with an interrupted thread adjacent the container mouth, for engagement with lugs or equivalent devices hereinafter referred to as lugs, on the cylindrical skirt portion of a corresponding cap, permitting the cap to be screwed on and off without the difficulty in locating the commencement of the thread, and excessive turning, associated with continuous screw threaded containers.

The expression interrupted screw thread, which is in common use, will be understood to mean a short multistart thread, the individual threads generally but not necessarily being so short that they do not overlap in an axial direction.

Hitherto, certain difliculties have been associated with containers of the kind referred to, especially as regards obtaining a satisfactory airtight seal. In the first place, any slight imperfections in the positioning or formation of the threads on the container or the lugs on the cap resulted in an uneven distribution of pressure amongst the several threads and even a failure of one or more threads to engage the cap. Next, it was generally impossible to give rise to an adequate sealing pressure by screwing on the cap without danger of fracturing the container, and the sealing pressure obtained was highly indeterminate. To enable even a moderate seal to be obtained by screwing, however, the caps were made of stiff metal, generally tin plate. Finally, because of the relatively stiff construction of the caps, they generally would not yield sufiiciently during a sterlizing operation to permit pressure air to escape in those cases where a vacuum seal was desired.

According to this invention, a container of the kind referred to is closed by placing over its mouth a cap formed with a cylindrical skirt, and then indenting this skirt at a plurality of circumferentially spaced positions to form lugs in situ engaging under the interrupted threads whilst the cap is pressed on to the container mouth.

The invention also consists in a method of sealing a container of the kind referred to, in which the indentation and the pressing of the cap over the container mouth are effected by relative vertical movement between the container and a sealing head provided with respective indentation-effecting members operative at a predetermined depth below the level of the container mouth, and in which said movement is preceded by the orientation of the container to a correct setting relative to said indentation members by mechanical means.

The method of this invention inherently involves the use of metal which can be deformed plastically in situ up to the thread elements and remain in gripping relationship thereunder. By contrast, in the case of seals having elastic pre-formed lugs, which will snap into position, the metal is initially deformed beyond its final position, and the seal can be removed and replaced without substantial change. Screw caps as hitherto employed, with preformed lugs, can readily be differentiated by their relative stiffness which is necessary to avoid over-screwing, as already explained.

In one convenient arrangement the containers are fed stepwise by a conveyor to a position below the sealing head, and incorporate a departure from symmetry on those parts touching the conveyor resulting in a predetermined orientation of the container on arrival under the sealing head, the latter being mounted at a corresponding orientation.

Alternatively, a mechanical container-orientating device may be operated to orientate the containers fed by the conveyor prior to arrival under the sealing head.

The invention further consists in a container of the kind referred to, sealed by a cap provided with a flow-in liner and a cylindrical skirt, the latter having spaced portions indented in situ engaging tightly under the respective thread elements.

With the aid of a suitable gasket, such as a ring of flow-in sealing composition, the process of this invention permits an airtight seal to be obtained, adequate, for example, for pickles without the aid of a vacuum and despite any slight irregularities in the screw threads of the container. At the same time, when the container is subsequently opened, the cap will behave as an ordinary screw-on cap showing all the convenience associated with caps of this type. If, however, it is desired to carry out some process on the container with the object of producing a partial vacuum therein, the cap, which can be made of thinner and softer metal than the hitherto popular stiff tinplate caps, will when so made yield more readily to release entrapped air.

Preferably, the cap has a reinforced (thickened or beaded) edge, which is indented in forming the lugs, and this reinforced edge is preferably uninterrupted. The indentation is best effected by spaced cap-engaging indentation-members which are, in operation, resiliently urged inwards, towards the container wall, at a predetermined depth below the container mouth, so that each lug is formed with substantially the same tight fit under the respective screw thread despite any slight ovality such as frequently occurs in moulded glass jars. For this purpose, the collet types of sealing head known by the registered trademark Omnia are particularly suitable. it will be understood that the container to be sealed must be suitably and carefully (i. e. mechanically as distinct from visually) oriented with respect to the sealing head so that the indentations are effected under the respective screw threads where the lower edge thereof is at a depth corresponding to a tight engagement with the lugs being formed. This need presents no difficulty with polygonal containers as the container feeding arrangements (guide rails on a conveyor, and/or star wheel feeding device) may be arranged to present the container to the sealing head with the required predetermined orientation. Indeed, any departurefrom complete symmetry on those parts of the container touching the feeding arrangements, such as the base and side Wall, can generally be made use of to ensure automatic orientation of the screw thread by the conveyor.

In a preferred arrangement the indented lugs formed in situ are parallel with the underside of the respective thread element. This is easily achieved by a corresponding orientation of the indentation-forming members of the sealing head.

The most suitable metal for thecap is aluminium or a ductile aluminium-base alloy of a thickness of about 0.01" (say 0.008"0.012"). The use of tinplate is not, however, precluded, and may be necessary for packing vegetables where the pressure generated during sterilizing cannot be counterbalanced.

An embodiment of this invention is illustrated in the accompanying drawings, of which:

Figure 1 is a side vieiw of the upper part of a jar,

Figure 2 is a sectional side view of a crown member and operating arm therefor,

Figure 3 is a sectional view on the lines A-BCD of Figure 2,

Figure 4 is a side view, with a part removed for clarity, of the crown member of Figure 2 in an operative position over the jar of Figure 1,

Figure 5 is a side view, partly in section, of a sealing head suitable for use on the jar after placing thereover a cap,

Figure 6 is an under view of the sealing head of Figure 5,

Figure 7 is a fragmentary half section on the line CC of Figure 6,

Figure 8 is a fragmentary section view showing the sealing operation,

Figure 9 is a fragmentary plan view of a cap after the indentation of a lug.

The jar shown in Figure 1 comprises a cylindrical body position 1 surmounted by an annular bead 2 and a mouth 3. Around the side of the mouth are spaced triangular projections 4 each having an apex 5 uppermost whilst the opposite base 6 constitutes a thread element, the elements together making up a multistart thread.

In the sequence of filling and sealing operations the filled jar will generally travel between guide rails in a pocket of an intermittent conveyor belt, or be held by a spring clip or clips carried by a star feed wheel, or otherwise be advanced stepwise at a predetermined spacing through a succession of halting positions. Above one of these, preferably immediately before that at which the sealing head is stationed, is suspended a crown member 7 (Figures 2-4) comprising a crown part 8 slidably housed within a concentric crown part 9. Fixed about and depending from crown part 9 is a guide bell 10 for locating a jar such as 1 down on to which crown member 7 is, in use, moved. Bell 10 is screwed on to part 9 by threads 11. Coaxial with, and housed between, parts 8 and 9 is a compression spring 12 encircling a central guide rod 13.

Depending from crown part 9 are spaced guide members 14 the lower ends of which are forked to define an inverted V-shaped recess with an apex 15. Depending from crown part 9 are spaced guide members 16 the lower ends of which are V-shaped, terminating in a point 17. Members 14 and 16 alternate and together define a cylindrical shell.

Crown part 9 depends from the end of a shaft 18 on which is slidably engaged a boss 19 at the end of an arm 20 extending from an adjacent sealing head (not fully shown) such as illustrated in Figure 5. A compression spring 21 is seated between boss 19 and crown part 9.

In operation, as the sealing head moves down over a capped jar to seal on the cap, arm 20 moves down and resiliently depresses crown member 7 so that bell 10 envelops the mouth of an as yet uncapped jar such as 1 standing below. If projections 4 are below guide members 16 (which correspond in number to the number of such projections round the jar month) they are pushed sideways by members 16 into the path of members 14. As the tips 17 of members 16 strike head 2 the downward movement of members 16 ceases, and spring 12 yields, but the movement of crown part 9 and members 14 continues, the sides of projection 4 sliding along the lower edge of members 14 until the apices S lodge in respective apices 15. At this point, for the small remainder of the downward movement of arm 20, spring 21 yields. When crown member 7 is lifted away from the jar, projection 4 will have an orientation corresponding to that of guide members 14.

Next, the oriental jar is conveyed to a position below the sealing head, where a cap is applied by well known means (not shown) and sealed on. The caps comprises a top 22, a gasket 23, a cylindrical skirt 24 and a bead 25 (Figures 8 and 9).

A suitable sealing head, such as is described in British patent specification No. 641,968, is shown in Figures 5-8, and comprises outer cantilever fingers 26, inner cantilever fingers 27 carried by crown parts 28 and 29 respectively. When fingers 27 have been positioned with their tips encircling bead 25 by engagement of a pressure plate 30 against the cap, downward movement of crown part 28 and hence of fingers 26 will cause the bevelled edge 31 of the latter to bear against the enlarged tips of fingers 27 (as shown in Figure 8) to press the latter inwards and cause the indentations of lugs 32 (Figure 9) in the cap head. These tips may, if desired, be shaped (i. e. concave) at their inner edge to follow the contour of the thread elements, and are preferably angled relative to the plane of plate 30 in the same way, i. e. at the same helix angle, as the thread elements. Fingers 26 and 27 are both resilient, the former being the stitfer.

What is claimed is:

l. A method of sealing a container having an interrupted thread adjacent the container mouth, by means of a cap formed with a cylindrical skirt and a sealing head provided with indentation-effecting members operable at a predetermined depth below the level of the container month, which comprises mechanically orientating the container to bring the thread elements thereof into correct register with said members, pressing the cap over the container mouth, and indenting the cap skirt and a plurality of spaced positions to form lugs in situ engaging under the interrupted thread elements by relative vertical movement between the container and sealing head with concomitant operation of the indentation-effecting members.

2. Apparatus for sealing a container having an interrupted thread adjacent the container mouth comprising a sealing head provided with indentation-effecting members circumferentially short in extent and spaced to correspond with the elements of the interrupted thread, a stepwise-operated conveyor for presenting containers successively to a position below the sealing head, means synchronised with the conveyor for effecting relative vertical movement between the container and sealing head, and container-orientating means for orientating successive containers fed by the conveyor prior to the arrival of the containers below the sealing head, the orientating means being set to align the interrupted thread elements of the successive containers with the indentation-etfecting members of the sealing head.

References Cited in the file of this patent UNITED STATES PATENTS

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