US2957595A

US2957595A - Closure cap

Info

Publication number: US2957595A
Application number: US826610A
Authority: US
Inventors: Roger B White; George F Chaplin
Original assignee: Continental Can Co Inc
Current assignee: Continental Can Co Inc
Priority date: 1959-07-13
Filing date: 1959-07-13
Publication date: 1960-10-25
Anticipated expiration: 1977-10-25
Also published as: FR1262324A; DE1182096B; OA01169A; NL253405A; GB890695A

Description

Oct. 25, 1960 Filed July 15, 1959 R. B. WHITE ETAL CLOSURE CAP 2 Sheets-Sheet 1 Oct. 25, 1960 R. B. WHITE ETAL 2,957,595

CLOSURE CAP Filed July 15, 1959 z Shoots-Sheet 2 120 g5;- r5: 6 er cea r eic/za am M WW United States Patent Ofifice Patented Oct. 25, 1960 CLOSURE CAP Roger B. White, Winnetka, and George F. Chaplin, Elmwood Park, Ill., assignors, by mesne assignments, to Continental Can Company, Inc., New York, N.Y., a corporation of New York Filed July 13, 1959, Ser. No 826,610

4 Claims. (Cl. 215-40) This invention relates, generally, to improvements and innovations in closure caps of the press-on, top-seal type for hermetically closing and sealing glass containers. More particularly, the invention relates to such closure caps which when lifted or pried up at one point will snap ofi from the container without being permanently distorted or deformed, and which may be repeatedly replaced and retained on the container by virtue of a plurality of circumferentially spaced detents which grip the exterior of the rim or lip of the container just beneath the sealing finish thereon.

Press-on type closure caps are applied by being pushed down or pressed down on the container as distinguished from being rotated or turned down as in the case of screw caps or lug caps, which may also be of the top-seal type. Press-on closure caps of the top-seal type are broadly old and have been extensively used for sealing glass containers containing food products such as jelly, peanut butter, cheese spread, pickles and food products of all types. For example, press-on closure caps of the top-seal type are shown in Patent 2,501,976. The upper edge or surface of the rim of a glass container on which such caps are used, provides the so-called sealing finish. A gasket formed of rubber-like resilient material carried in the top of the closure cap fits down on this sealing finish so as to form a hermetic seal thereon. In applying such caps to filled containers, a small headspace is left unfilled at the top of each container which becomes filled with steam vapor when the cap is initially applied and pressed down in the capping machine. The hermetic seal which is initially formed due to mechanical pressure is perfected and maintained when the steam or vapor in the headspace condenses creating a vacuum.

Heretofore, when closure caps of the press-on, top-seal type were removed, they were often distorted or bent incidental to being pried off. As a result of being thus substantially bent or distorted, these caps would not completely cover or close the container on being reapplied as a dust cover when only a portion of the contents had been removed. Rather, the caps merely sat or rested on the tops of the glass containers and normally an open space was left at the place where the caps had been bent up in being pried ofi.

In spite of this drawback, closure caps of the presson, top-seal type have been extensively used for a number of years since: they are inexpensive; can be machine applied at high capping rates; provide permanent hermetic seals which rarely fail; and, form attractive closures.

The object of this invention, generally stated, is the provision of improved press-on, top-seal type closure caps for glass containers which retain all of the desirable features of prior caps of this type but are characterized in that upon being pried oif at one point, instead of distorting or bending, the entire cap snaps off from the container with practically no permanent distortion.

A further important object of the invention is the provision of press-on closure caps of the top'seal type which have a plurality of detents of such location, number and formation that they serve to properly orient or locate the closure caps on the containers during initial application, and serve to firmly grip the exteriors of the glass containers and thereby firmly retain the closure caps" in place when they are reapplied to the containers soas to serve as covers and keep the containers tightly closed.

Certain other objects of the invention will, in part, be obvious and will in part appear hereinafter.

For a more complete understanding of the nature and scope of the invention, reference may now be had to the following detailed description thereof taken in connection with the accompanying drawings, wherein:

Fig. 1 is a side elevational view of a glass container hermetically sealed with a press-on, top-seal closure cap constituting one embodiment of the present invention.

Fig. 2 is a top plan view of the closure cap shown in Fig. 1;

Fig. 3 is a bottom plan view of the closure cap shown in Fig. 1 removed from the container;

Fig. 4 is a fragmentary detail sectional view on enlarged scale taken on line 4-4 of Fig. 3.

Fig. 5 is a view similar to Fig. 4 but taken on line 5-5 of Fig. l and showing the manner in which the top seal gasket and detents interfit with the finish and side wall, respectively, of the glass container; and

Fig. 6 is a detail sectional view corresponding to Fig. 5 and taken through a modified form of the closure cap held in sealing relationship on a straight sided tumbler.

In Fig. 1 a glass container 5, such as an ordinary jelly glass or tumbler having a bead finish, is sealed with a closure cap 6. This food package illustrates but one of a wide number of large volume uses of the closure caps forming the subject matter of this invention. The

invention pertains to certain specific features of the or printed with trademarks, brand names, etc., while the V closure cap 6 which will now be described in connection with Figs. 2-5.

The closure cap 6 comprises a cap body or shell having a top panel portion 7 (Fig. 4) and a depending skirt portion designated at 8. An inturned bead formation, indicated generally at 10, is integrally formed on the bottom of the skirt 8 and it is in connection withthis head 10 that the novel features of the invention reside.

Cap bodies or shells of the type used in making cap 6, can be stamped out from suitably coated tin plate, although other materials may be used. The machinery and methods for stamping out the cap bodies or shells, and then forming the bead 10, are broadly old and do not form a part of the present invention. Usually, the tin plate is enambled on the exterior and often decorated interior is enameled or coated with a known lacquer formulation so as to form a protective coating on the interior of the cap body or shell and give the interior an attractive appearance. Usually white, or off-shade White, enamels are used on the interior, although other shades and colors may be utilized.

In addition to the shell, the second main element or component of the closure cap 6 is a resilient, rubber-like top seal gasket indicated generally at 11. I

In the particular cap shown in Figs. '2-5, the top panel has a continuous annular shoulder 12 located radially inward of the periphery of the cap so as to define the inner wall of a gasket retaining channel, the outer wall. being defined by the rounded portion 13 of the cap shell where the side wall or skirt 8 joins the top panel portion 7. The gasket 11 may be of the flowed-in, plastisol type. This type of gasket and the details of the retaining channel therefor and the so-called inner thin feather-edge 14 thereon, are described in detail in Zipper Patent 2,841,304.

The hollow bead 10 is integrally formed on the bottom of the skirt 8 by a series of forming operations of generally known type using generally known dies and equipment. While the forming technique and equipment are generally known, the hollow head 10 incorporates certain innova: tions which make the cap 6 different in the above-mew tioned significant respects from press-on, top-seal caps of the prior art.

Referring first to Fig. 3, it will be seen that'the bead 10 is circumferential or continuous and it will be noted that it contains six detents 1515 each of which is of equal length, and equally spaced apart. Except for minor variations coming within predetermined tolerances, the detents 15 are all identical. There may be fewer or more than six detents, but six is a preferred number. in the cap shown the combined lengths of all six detents equals approximately 36% of the inner circumference of the bead 10. However, this relationship may vary from 30-42% as a preferred range, with the individual detents occupying from 7% of the inner circumference of the bead as a preferred range. When a different number of detents are used, the preferred length of each detent is still from about 5 to 7% of the inner circumference.

Referring now particularly to Fig. 4, it will be seen that this cross section is taken midway through one of the detents 15. Intermediate the detents a transverse cross section through the bead 10 as at bb in Fig. 3, would show it to be hollow and generally circular, this formation being indicated in broken line at 16 in Fig. 4. Adjacent the end of one of the detents 15 a cross section as at aa would show the detent as represented by the broken line designated at 17 in Fig. 4. It will be seen that each detent 15 at the middle portion has cross section which is generally fishhook shaped as shown in Fig. 4. That is, it has a curved bottom portion 18 and a generally straight shank portion 20 after the manner of the conventional simple fishhook. The arcuate portion 18 has substantially the same radius of curvature as that of the hollow head 10. The shank portion 20 will be seen to be approximately tangent to the bead or the curved portion and it will be seen that it is inclined upwardly and inwardly toward the center of the cap.

In order to present a smooth surface for engaging the glass finish, as well as to facilitate the manufacture of the hollow bead and detents, the upper or free end of the shank 20 is rolled or curved as indicated at 21.

It will be seen that the uppermost end or portion 21 of each detent l5 lies substantially above the top of the hollow bead 10, and also substantially radially inwardly thereof. By virtue of being so placed, the upper end of each detent 15 is positioned so as to engage and grip each glass container immediately under the rim or top finish, e.g. bead, thereof.

Certain proportions and related dimensions of the cap shell, hollow bead 10 and the detents 15 are important and preferred proportions and relationships exist. Referring to Fig. 4 it will be noted that the overall height of the closure cap 6 is indicated by the dimension A; the height of the detents 15 is indicated at B; while, the height (and also the diameter) of the hollow bead 10 is indicated at C. In general, the dimension B is approximately twice the dimension C. Furthermore, the dimension C is approximately one-third of the dimension A. By virtue of such proportioning, together with the formation and contour of the detents 15 and the hollow bead 10, the cap 6 is given a new type of action not previously obtained in press-on, top-seal closure caps. This new action will now be further described in connection with Fig. 5 which depicts the relationship of parts and elements of the closure cap with respect to the glass finish on the upper edge or rim of the container, this finish being designated generally at 22 in Fig. 5. It will be seen that the finish 22 is embedded into the gasket 11 so as to displace the same or bulge it up as it were, on opposite sides of the finish. By reason of this relationship an excellent seal is obtained and any variations in the glass finish are accommodated for. It will also be seen that the detent 15, that is the shank 20 thereof, has been bent or sprung so that the upper free end 21 fits underneath the bead 23.

By reason of the hollow bead and detent construction the two following features are incorporated into the caps 6. First, the hollow bead so rigidifies the side wall or skirt 8 of the shell of the cap that the cap as a whole has a high resistance to being deformed, bent or sprung when pressure to pry off is applied underneath it at any one point. When the sealed container comes to the consumer and it is necessary to open it for the first time, the cap 6 is retained on the container through the combined forces of the vacuum in the headspace as well as the gripping of the detents underneath the bead 23. These two combined retaining forces must be overcome to remove the cap 6 from the container and thus gain access to the contents. However, the rigidity imparted by the rather large hollow bead 10 is such that this together with the skirt 8 provides sufficient rigidity to the shell so that upon being pried off at any one point, instead of permanently bending or distorting, the whole cap gives all at once and snaps off as it were all away around. When the removed cap is examined it is not seen to be noticeably bent or distorted.

Another feature is that the bead construction 10 in cooperation with the detents 15 eo-acts to provide a detent gripping action with a substantial amount of resilience built into it. In other words, each of the detents 15 in combination with the hollow bead lying on either side of it, in effect acts as a spring finger extending from a coil spring. In other words, when the shank portion 20 of the detent is deformed by application of pressure on the upper end 21, the whole detent tends to be inwardly deformed or curled as well as the bead lying adjacent either end of the detent. In fact, the hollow bead tends to roll up or tighten up. Therefore, a substantial resistance to deformation is built into each of the detents 15 and yet the detents can give or move to a substantial degree without becoming permanently bent or set. Thus, maximum use is made of the normal springiness or resilience of the material to provide a firm but yielding gripp1ng action.

After the cap 6 has been removed, it can again'be manually reapplied and pressed down into place in substantially the same position and relationship as shown in Fig. 5. While the re-seal will not be truly hermetic, it will be fairly air tight and the cap 6 will be definitely retained on the container. However, having once been opened and the vacuum having been broken, the cap may now be removed readily by hand. Hence, it may be snapped in place and removed at will as often as desired. Accordingly, the cap has a very high degree of utility after the container or package has once been opened.

In Fig. 6 a second embodiment of the invention is shown in association with a different container. In this case the glass container indicated generally at 25 does not have a bead at the top, however, it is sufiiciently tapered or slanted to give much the same effect. In this case the cap is indicated generally at 26 and comprises a metal shell having a completely flat top panel portion 27 and a straight side wall or skirt portion 28. At the bottom edge a hollow bead construction is indicated at 3t] including a plurality of detents having shank portions 31 and upper edges 32. If desired, the hollow bead construction 30 and the detent formations included therein may correspond to the hollow bead 10 and detent formations 15 described above in connection with cap 6 in Figs. 2-5.

Instead of having a flowed-in plastisol gasket, cap 26 has a preformed ring gasket which may be formed of rubber or rubber-like material suitable for gasket purposes. This gasket is indicated at 33 and it may be suitably adhered to the interior of the cap shell so as not to be displaced in handling or use. The cap 26 acts in generally the same way as does cap 6. That is, it may be sprung oil from the closed container without distortion or bending and may thereafter be reapplied and removed as often as desired. The detents also serve to firmly grip the exterior of the glass container 25 and to retain the caps 26 thereon in a firm manner.

The detents in addition to retaining the caps on the containers, also serve to center or position the caps with respect to the glass containers both during original application in the closure applying machines as well as on manual reapplication of the closure caps after having been initially removed.

It will be obvious that only a small portion of the area of each detent actually engages the side wall of the glass containers, this portion being the middle of the upper edge of each of the detents. Since the area of contact is small, the pressure is relatively high. However, this relatively high pressure area of contact is completely surrounded or backed up by a resilient structure as explained above, provided not only by each detent itself but also by the hollow bead construction lying on opposite sides of each detent.

It will be seen that tthe straightened out length of a hollow bead as well as the straightened out length of the detents are also substantially equal. This necessarily follows from the fact that as originally stamped or blanked out the side walls of the shells have the same height all the way around. The first operation is to apply the slight inturn or curl 21 or 33 on the free edge of the side wall and thereafter the hollow bead and the intermediate detents are formed. This is all done on automatic machinery using suitable dies and fixtures of known type.

It will be understood that certain modifications and changes in details may be made in the closure caps described above and illustrated in the accompanying drawings without departing from the spirit and scope of the invention.

What is claimed as new is:

l. A closure cap of the top seal type for use in establishing and maintaining a hermetic seal on a glass container of the type in which the upper edge of the rim of the container constitutes a hermetic sealing finish; said cap comprising a cup-shaped shell having a generally flat top panel portion and a depending skirt portion, and a sealing gasket positioned within said shell for sealing engagement with said sealing finish when the cap is held down on the container; and said skirt portion having a hollow inturned integral bead formed of the shell material around the bottom thereof, said bead including a plurality of approximately equi-spaced detents for engaging the exterior of the container below said sealing finish and thereby locating and retaining said closure cap on said container, said bead being substantially closed and generally circular in transverse crosssection intermediate said detents, and said detents being generally fishhook shaped in transverse cross-section through the midportion thereof with the curved bottom portions having substantially the same radius of curvature as the bottom portion of said bead, and with the shank portions being approximately tangent to said bottom curved portions and upwardly and inwardly inclined toward the center of said cap whereby the uppermost end of each detent occupies a position substantially above and inside said bead, said head and detents having substantially equal straightened-out lengths at all cross-sections therethrough.

2. The closure cap called for in claim 1 wherein the upper free edges of each detent are curled over toward the outside of said cap so as to provide a smooth inner surface on each detent.

3. The closure cap called for in claim 1 wherein the length of each of said detents equals from about 5 to 7 percent of the inner circumference of said head.

4. The closure cap called for in claim 1 wherein the diameter of said head is approximately one-third of the overall height of said cap, and the height of each detent is approximately twice said diameter.

References Cited in the file of this patent UNITED STATES PATENTS