US3371463A - Method for crimping crown caps - Google Patents

Description

March 5, 1968 G. E. ROBERTS 3,371,463

METHOD FOR CRIMPING CROWN CAPS I Filed Feb. 4, 1965 Gsbkas E Rbsaars INVENTOR.

BY Q] ca I United States Patent 3,371,463 METHOD FOR CRIMPING CROWN CAPS George E. Roberts, New York, N.Y., assignor to United States Crown Corporation, Saddle Brook, N.J., a corporation of Delaware Filed Feb. 4, 1965, Ser. No. 430,379 2 Claims. (Cl. 53-42) ABSTRACT OF THE DISCLOSURE There is disclosed a method of application of forces to crimp a crown cap and/ or a crown cap having an initially generally horizontally radially extending tab. The method permits the positioning of the cap in any radially oriented position on the top of the neck of the container to which it is to be crimped. There is simultaneously applied forces to the top edge of the cap and to the top of its tab at points lying on a force applying locus extending through the top edge application of force position on the cap and lying 45 to 60 degees from the vertical axis through the cap as measured in a direction below the tab and towards the container axis. Continuing with the application of these forces while applying an inwardly directed radial force around the wall of the cap to bend it in while bending the tab downwardly and into an upwardly convex shape as viewed in cross section to fully crimp the wall into locking engagement with the neck and further deform the tab downwardly and inwardly towards the container.

This invention relates to a method particularly well adapted to attach a crown cap with a radially projecting tab to the neck of a bottle.

In the bottling industry, it has long been known that a conventional crown cap may be provided with an integral tab which extends from the lower edge of its corrugated wall, to provide the necessary leverage for removing the cap from a bottle without the aid of a separate opener. The use of this type of crown cap has produced its own variety of problems, especially in conjunction with the high speed equipment used to apply crowns in modern bottling plants. These machines use a die, either unitary or radially segmented, which comes down over the bottle neck to crimp the cap onto the bottle. Obviously, these must be modified to accommodate tabbed crown caps. Normally, the modification has involved the cutting away of a small portion of the die, or throat as it is usually called. This has not been altogether satisfactory since a throat so modified can be used only for the tabbed crown caps, and must be replaced if the bottler resumes production with the usual untabbed crowns. The down time of the bottling equipment has been an undesirable effect of this. Also, the sealing characteristics of these dies were not always reliable. If the tab of a cap were only slightly off-center from the cut-away portion of the throat, it would cant the cap on the bottle prior to the crimping of the corrugations, which prevented the proper sealing of the cap.

Accordingly, it is an object of this invention to provide a method of crimping tabbed crown caps onto necks of bottles so that there is no unusual sensitivity to the precise radial location of the tab with respect to the crimping throat, so that uniform and satisfactory sealing is assured.

Another object is to provide a method which will not limit the apparatus employed only to use with tabbed crown caps; but rather the apparatus will have the versatility of being usable for either regular crowns or tabbed crowns. This eliminates the need for equipment changeover and reduces the down time of the bottling equipment.

The present invention will be understood after reference to the following description and the attached drawings wherein:

FIG. 1 is a sectional view of a crimping throat commencing to crimp the corrugations of a tabbed crown to a bottle neck and to bend the tab into the desired configuration;

FIG. 2 is a sectional view, similar to that of FIG. 1, showing the relative positions of the crimping throat and cap at the conclusion of the crimping operation;

FIG. 3 shows the crimping throat of FIGS. 1 and 2 used with a conventional crown cap without a tab; and

FIG. 4 shows the curvature of the tab, as seen along the line 4-4 in FIG. 2.

The environment of this invention is well known to those in the art and will be described here only briefly. A horizontally moving supporting surface is used to hold the bottles as the caps are applied. Above the necks of the bottles is a platform with a slot for receiving the caps from a dispensing chute. The general type of platform may vary, but a representative example is shown in US. Patent 2,883,818 issued to Marion W. Gieskieng on Apr. 28, 1959. The platform, when holding the cap, is bodily lowered to deposit the cap on a bottle. Then, the crimping throat descends over the cap and the bottle neck to secure the cap to the bottle. During this crimping operation, downward pressure is exerted on the cap by means of a presser foot which extends through the bore of the crimping throat.

The details of the crimping throat 2 used in this invention are shown in the drawings. It is a generally toroidal body with a central bore 4. A major portion of the bore has a generally cylindrical wall 6 which may taper slightly inwardly and upwardly, to the maximum angle of one degree to the central axis of the bore. At the lower edge of the wall is a rounded shoulder 8 which leads to a generally conical surface 10. This surface 10 is inclined to the central axis of the bore from 45 to 60 degrees, in order to impart the curvature to the tab of a crown cap. The axial extent of this conical surface 10, indicated at a, is approximately equal to the height of the cap wall after it is crimped.

The method of employing this crimping throat 2 to attach a crown cap to a bottle is shown sequentially in FIGS. 1 and 2. Initially, the surface 10 contacts both the tab 12 and the outturned corrugations 14 of the cap, to evenly act on all sides of the cap and prevent disturbance of its position on the neck 16 of the bottle. By virtue of the limited dimension as, there is no unequal distribution of forces on the cap which might tend to misorient it.

As the throat 2 descends, the smooth, inverted, generally conical surface bends the tab into its upwardly convex shape, shown in FIG. 4. Simultaneously, the wall 6 and shoulder 8 subject the upper portions of the cap wall at points of equal height and throughout its circumference to forces which bend the wall inwardly. This retains the cap in its centralized location on the neck 16 of the bottle, and it provides for a uniiform crimping action even in the area of the tab.

Continued advancement of the throat 2 will fully bend the cap wall into locking engagement with the bottle neck and further deform the tab, until the throat reaches its final position shown in FIG. 2. The bottle is then withdrawn from the throat.

The utility of this method is, of course, restricted to those crowns which have tabs of a significant width which permits them to be bent into the shape shown in FIG. 4. Such tabs will extend at least 45 degrees along the wall of their caps.

In reviewing the above-described method, it will be noted that there is nothing crucial about the radial relation of the tab to the crimping die. If the means which places the cap on the bottle locates it in any angular position, the die is capable of properly crimping it in place. This was not the case in the prior art.

Since bottlers will often wish to crimp normal, untabbed crowns onto their bottles, the crimping die disclosed herein is also capable of performing that function. The ability to do this is shown in FIG. 3, where both the conical surface 10 and cylindrical surface 6 have caused the corrugations to be bent inwardly.

In summary, it has been shown that the present invention presents a step forward in the bottling art, inasmuch as it provides a method for reliably crimping a tabbed crown cap on a bottle and deforming its tab, without a great sensitivity to the location of the tab. Furthermore, the apparatus which performs this process is capable of performing equally well known conventional crown caps which have no tabs.

It is realized that this invention may assume many forms other than the single one shown. Therefore, it is understood that the scope of this invention is not limited by the above description, but by the claims Which follow.

I claim:

1. The method of crimping a crown cap on the neck of a container, said 'crown cap having a depending outwardly flared corrugated wall with a radially projecting corrugated upper surface tab that extends at least 45 degrees along the wall of the cap in an initial horizontal attitude, comprising the steps of (a) placing the cap on the container neck;

(b) simultaneously applying forces throughout the whole top edge of the cap and to the top of its tab at points lying on a force applying locus extending through the top edge application of force position on the cap and lying 45 to 60 degrees from the central axis through the cap as measured in a direction below the tab and towards the container axis;

5 (c) continuing the application of such forces while applying an inwardly directed radial force around the whole wall of 'said cap to bend in said wall while bending the tab downwardly and into an upwardly convex shape in cross section; and

(d) continuing the application of all these forces to fully crimp said wall into locking engagement with said neck and further deform said tab downwardly and inwardly towards the container.

2. The method of claim 1 wherein the area of extent of said simultaneously applied forces in step (b) is approximately equal to the area of said cap wall after crimping.

References Cited FOREIGN PATENTS 3/1951 Italy. 7/ 1931 Germany.

TRAVIS s. MCGEHEE, Primary Examiner.

R. L. FARRIS, Examiner.

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