US3907156A

US3907156A - Container end closure with metal plate

Info

Publication number: US3907156A
Application number: US481164A
Authority: US
Inventors: Iii Albert J Weatherhead
Original assignee: Weatherchem Corp
Current assignee: Weatherchem Corp
Priority date: 1973-02-01
Filing date: 1974-06-20
Publication date: 1975-09-23
Anticipated expiration: 1992-09-23

Abstract

A dispensing container is disclosed which includes a fiber tube, a metal top plate having an opening, and a plastic self-locking end closure received within the opening. The locking feature includes a plurality of relating narrow, peripherally spaced, axially extending radially reinforced barbs, one of which engages the rim of the opening.

Description

United States Patent 1 Weatherhead, III

CONTAINER END CLOSURE WITH METAL PLATE Inventor: Albert J. Weatherhead, lll, Shaker Heights, Ohio Assignee: Weatherchem Corporation, Twinsburg, Ohio Notice: The portion of the term of this patent subsequent to Apr. 1, 1992, has been disclaimed.

Filed: June 20, 1974 Appl. No.: 481,164

Related US. Application Data Continuation-in-part of Ser. No. 328,876, Feb. 1, 1973, Pat. No. 3,874,580.

US. Cl. 220/307 Int. Cl 865d 39/00 Field of Search 222/566, 563, 480, 545;

[ 5]*Sept. 23, 1975 [56] References Cited UNITED STATES PATENTS 2,868,410 1/1959 Henchert 220/307 3,300,106 1/1967 Chmela 222/563 X 3,370,757 2/1968 Foster 222/480 X Primary Examiner-Robert B. Reeves Assistant ExaminerHadd Lane Attorney, Agent, or Firm-McNenny, Farrington, Pearne & Gordon 57 ABSTRACT A dispensing container is disclosed which includes a fiber tube, a metal top plate having an opening, and a plastic self-locking end closure received within the opening.

The locking feature includes a plurality of relating narrow, peripherally spaced, axially extending radially reinforced barbs, one of which engages the rim of the opening.

10 Claims, 6 Drawing Figures CONTAINER END CLOSURE WITH METAL PLATE This application is a continuation in part of copending application Ser. No. 328,876, filed Feb. 1, 1973, now U.S. Pat. No. 3,874,580 of Apr. 1, 1975.

BACKGROUND OF THE INVENTION This invention relates generally to plastic end closures. and more particularly to a self-locking plastic end closure for use on a metal plate or base.

Paper fiber tubes (that is, tubes which include layers of fiber material wound such as in a helix one upon the other and secured together by an adhesive) have become widely used for dispensing containers in the food packaging industry. The paper of such tubes may be plain or it may be coated, waxed, resin impregnated, or combined with other foils or films to provide a satisfactory container for various types of food products. The tubes are cut to the desired length of the container, and each end of the tube is closed.

A variety of structures are used for closing the ends of the fiber tube. One such structure provides a plastic 1 end closure which is received within the tube such as disclosed in U.S. Pat. No. 2,961,132. Another such structure provides a metal plate which is seamed to the fiber tube and which includes an opening which is closed by a suitable plug or by a plastic end closure of the type disclosed in U.S. Pat. No. 2,961,132.

When the end of the fiber tube is closed by a metal plate and plastic end closure, a tight interference fit between the plastic end closure and the opening in the metal plate is provided to hold the end closure on the metal plate. This arrangement is not entirely satisfactory, since the plastic end closure may crack upon assembly if the interference fit is too tight or may not be held sufficiently tight if the interference fit is too loose.

SUMMARY OF THE INVENTION The present invention provides a self-locking end closure for use with a metal plate. The end closure is of plastic and includes a generally flat laterally extending end portion. An annular skirt portion extends axially from the end portion, and the skirt portion has a generally smooth outer surface for being received within an opening in the metal plate.

A plurality of relatively narrow locking means are arranged in peripherally spaced positions 120 apart on the end closure for securing the end closure onto the metal plate. Each of the locking means includes a plurality of axially spaced locking barbs extending radially outwardly from the outer surface of the skirt portion and terminating at an outermost barb surface. A reinforcing strut extends from the end portion to the skirt portion immediately adjacent the locking barbs and acts against radially inward movement of the locking barbs. The arcuate extent of the locking barbs of each locking means is quite small, being less than 10 and in a preferred embodiment being not greater than 3.

The reinforcing strut pushes the locking barbs against an annular surface which defines the opening in the metal plate, so that the outermost barb surface of the locking barbs which are pushed past the annular surface upon assembly are held radially outwardly beyond such annular surface to prevent removal of the end closure. Because the arcuate extent of the locking barbs of each locking means is very small, the force required to assemble the end closure onto the metal plate is minimized to prevent breakage of the plastic end closure during assembly. In actual tests which have been conducted on the invention, it has been found that the end closure can be removed from the metal plate only upon shearing off the locking barbs, yet the plastic end closure can be assembled onto the metal plate without breaking.

BRIEF DESCRIPTION OF THE DRAWINGS These and other aspects and advantages of the invention will become readily apparent to those skilled in the art upon an understanding of the preferred embodiment of the invention shown in the accompanying drawings, wherein:

FIG. 1 is a perspective view ofa dispensing container according to the principles of the invention;

FIG. 2 is a side elevational view of the plastic end closure for the metal top plate of the dispensing container shown in FIG. 1;

FIG. 3 is a bottom plan view of the plastic end closure shown in FIG. 2;

FIG. 4 is a cross-sectional side elevational view of the end closure shown in FIG. 2;

FIG. 5 is an enlarged cross-sectional view taken along reference view line 55 in FIG. 1 showing one of the locking means provided by the present invention; and

FIG. 6 is an enlarged bottom view of the locking means shown in FIG. 5.

DETAILED DESCRIPTION OF THE DRAWINGS Referring now to the drawings in greater detail, FIG. 1 is a perspective view of a dispensing container according to the principles of the invention. The dispensing container shown in'FIG. l is particularly adapted for use with food products and includes a fiber tube 11. The tube 11 is well-known in the art and includes layers of heavy craft paper disposed'in a helix one ,uponthe other and secured together by an adhesive. The dispensing container shown in FIG. l alsoineludes a metal bottom plate 12 and a metal top plate l3 which are secured on the ends of the fiber tub'e ll in a well-known manner by a seaming operation. A plastic end closure 14 'is secured in an opening in the top plate 1.3 in a manner described below for opening and closing the container.

FIGS. 2, 3, and 4 show the plastic end closure 14 in greater detail. The top end closure 14 is shown in the copending U.S. Pat. application of applicant, Ser. No. 328,876 filed Feb. 1, 1973, and includes a stationary cap 15 and a rotatable disc 16. The cap 15 and disc 16 are each injection molded, and the cap 15 is preferably made of a medium impact styrene while the disc 16 is preferably made of flexible polyethylene. This provides a stationary cap which is rigid and a rotatable disc which is flexible so that the disc can be snapped onto the cap without breakage.

As best seen in FIGS. 1 and 4, the rotatable disc 16 includes a large arcuate shaped opening 17 for pouring or for receiving a spoon and a plurality of smaller openings 18 for dispensing the contents of the container by shaking. The rotatable disc 16 also includes a depending axle portion 19 which is snapped into a suitable opening in the center of the stationary cap 15, and the disc 16 is rotated to bring the

openings

17 or 18 into alignment with a suitable opening formed in the stationary cap 15 and described below.

The construction of the stationary cap is shown in detail in FIGS. 2, 3, and 4. The cap 15 includes a laterally extendingend portion 23 and an annular skirt portion 24 extending axially from the end portion 23.

The end portion 23 includes a support portion 26, an axially recessed center portion 27, and a conical connecting portion 28 extending between the support portion 26 and the recessed center portion 27. An axially facing annular lip 29 is provided for axially engaging the top plate 13 to limit movement of the end closure 14 upon assembly of the end closure 14 onto the top plate 13 as described below. The axially recessed center portion 27 includes a removable tab 30 which is defined by a reduced thickness outline portion 31 so that the tab 30 can be removed in the manner disclosed in U.S. Pat. No. 2,961,132 to permit dispensing the contents of the container through the large opening 17 or the smaller openings 18.

The skirt portion 24, as shown in FIGS. 3 and 4, is substantially cylindrical and extends axially from the end portion 23 for being received within the metal base 13. The skirt portion 24 includes an inner surface 33 and a smooth outer surface 34, and the free end of the outer surface 34 is tapered to provide an entrant surface to assist in the assembly of the end closure 14 onto the metal top plate 13. The diameter of the outer surface 34 is approximately three inches in the embodiment shown in the drawings.

As shown in FIGS. 2 through 5, the plastic end closure 14 also includes a plurality of locking means 35. The locking means 35 are arranged in peripherally spaced positions on the end closure 14, and the structure of each of the three locking means is identical. Each locking means includes a plurality of axially spaced locking barbs, 40, 41, 42, 43 and 44 (FIG. 5), each of which extend radially outwardly approximately 0.015 inches from the outer surface 34 of the skirt portion 24 and each of which terminate at a radially outward most barb surface which is a sharp edge in the preferred embodiment. Each locking means 35 also includes a reinforcing strut 50, and each reinforcing strut 50 extends from the portion of the inner surface 33 adjacent the locking barbs through 44 radially inwardly to the support portion 26 and the recessed center portion 27 and the connecting portion 28.

The construction of the metal top plate 13 is best shown in FIG. 5. The metal top plate 13 in the preferred embodiment is a thin steel stamping. A round opening is provided in the top plate 13 which is defined by a generally tubular axially extending annular marginal wall 53 which terminates at an annular marginal edge 54. The outer periphery of the metal plate 13 includes a reversely bent seamed portion 55 which clamps the metal top plate 13 onto the top end of the tube 1 1.

When the end closure 14 is to be assembled onto the metal top plate 13, it is properly aligned vertically above the opening in the top plate 13 as viewed in the drawings and is displaced axially onto the plate 13. This is commonly done with automatic machinery which positions the end closure 14 and applies a force to the support portion 26 to push the end closure onto the top plate 13.

The inside diameter of the marginal wall 53 and the outside diameter of the outer surface 34 (that is, the diameter of the cylindrical portion of the outer surface 34 from which the locking barbs project) are dimensioned to provide an interference fit. As may be best seen by reference to FIGS. 5 and 6, each locking means 35 and a portion of the outer surface 34 immediately adjacent thereto is deformed radially inwardly from its free or normal configuration illustrated in FIG. 3 when the end closure 14 is assembled onto the top plate 13. This is because the cylindrical marginal wall 53 is sufficiently inelastic as to undergo little or no deformation upon such assembly, and the relatively more elastic end closure 14 deforms radially inwardly to accomodate the interference between the locking means 35 and the marginal wall 53.

As the individual locking barbs 40 through 44 are pushed into the marginal wall 53 during assembly, the outermost barb surface (which is a sharp edge in the preferred embodiment) is deflected radially inwardly relative to the outer surface 34 (FIG. 5). After the

individual barbs

43 and 44 are pushed through and past the marginal wall 53, the resilience of the

individual barbs

43 and 44 permits the radially outermost surfaces of the

barbs

43 and 44 to snap radially outwardly back to their free or normal position as shown in FIG. 5, so that the radially outermost surface of the

barbs

43 and 44 is disposed radially outwardly from the marginal wall 53 and the marginal edge 54 engages the locking barb 43 to lock the end closure 14 on the top plate 13. The reinforcing strut 50 acts against radially inward movement of the locking means 35 to insure that the radially outermost surfaces of the

barbs

40, 41, and 42 are pushed radially outwardly against the marginal wall 53 and to hold the

barbs

43 and 44 in a position radially outwardly from the marginal wall 53. In actual tests on the invention, it has been found that the engagement between the marginal edge 54 and the

barbs

43 and 44 is such that the end closure 14 can be removed only by exerting a force of sufficient magnitude on the end closure 14 as to break off the locking

barbs

43 and 44.

Because of the multiplicity of barbs provided on each locking means 35 (five barbs in the preferred embodiment), the marginal edge 54 will engage one of the barbs 40 through 44 even if the axial length of the marginal wall 53 varies significantly. Thus, if the marginal wall 53 is longer than shown in FIG. 5, the marginal edge 54 may engage the barb 44 rather than the barb 43, while the marginal edge 54 may engage the barb 42 rather than the barb 43 if the marginal wall 53 is shorter than shown in FIG. 5.

As further shown in the drawings, the locking means 35 are remotely spaced about the circumference of the skirt portion 24, and the locking barbs of each locking means extend only through a small arc. The locking means 35 are spaced circumferentially apart by an arc of at least and in the preferred embodiment the locking means are apart. The locking barbs of the locking means each extend circumferentially through an are 57 (FIG. 3) of less than 10, and in the preferred embodiment the locking barbs each extend through an arc of not greater than 3. This feature of the invention concentrates the resilient force created by the interference between the locking means 35 and the marginal wall 53 to provide a self-locking end closure in which the locking barbs tightly lock against the marginal edge 54 in the manner illustrated in FIG. 5. Furthermore, this feature of the invention minimizes the axial force required to assemble the end closure 14 onto the top plate 13 to prevent breakage of the end closure 14 during assembly.

Although a preferred embodiment of this invention is illustrated it is to be understood that various modifications and rearrangements of parts may be resorted to without departing from the scope of the invention disclosed and claimed herein.

What is claimed is:

1. In combination, an end closure and a metal plate, said metal plate including an axially extending marginal wall terminating at a marginal edge and defining an opening, and said end closure being plastic and including a laterally extending end portion, an annular skirt portion extending axially from said end portion, said skirt portion having an inner surface and a generally smooth outer surface being received within said marginal wall, and a plurality of relatively narrow locking means disposed in peripherally spaced positions holding said skirt portion in said marginal wall, each of said locking means including a plurality of axially spaced locking barbs extending radially outwardly from said outer surface and terminating at an outermost barb surface, reinforcing strut means extending from said end portion to said inner surface immediately adjacent said locking barbs and acting against radially inward movement of said locking barbs, said marginal wall radially engaging and radially inwardly deforming said outermost barb surface of at least one of said barbs disposed nearer to said end portion, and said marginal edge axially engaging at least one of said barbs disposed farther from said end portion to lock said end closure onto said metal plate.

2. The combination in accordance with claim 1 wherein said locking barbs each extend through an arc of less than ten degrees.

3. The combination in accordance with claim 2 wherein said locking barbs each extend through an arc of not greater than three degrees.

4. The combination in accordance with claim 2 wherein said locking means are one-hundred twenty degrees apart.

5. The combination in accordance with claim 1 wherein said end portion includes a generally flat axially recessed center portion, and each of said reinforcing struts extend between said inner surface adjacent said locking barbs and said recessed center portion.

6. The combination in accordance with claim 1 wherein said locking means provide the sole means for holding said end closure on said metal plate.

7. The combination in accordance with claim 1 wherein said outer surface of said skirt portion from which said locking barbs project and said marginal wall of said metal plate are dimensioned to provide an interference fit therebetween.

8. In combination, an end closure and a metal plate, said metal plate including a marginal surface defining an opening, and said end closure being plastic and including a laterally extending end portion, an annular skirt portion extending axially from said end portion, said skirt portion having an inner surface and a generally smooth outer surface being received within said marginal edge, and a plurality of relatively narrow locking means disposed in peripherally spaced positions holding said skirt portion in said marginal edge, each of said locking means including a plurality of axially spaced locking barbs extending radially outwardly from said outer surface and terminating at an outermost barb surface, reinforcing strut means extending from said end portion to said inner surface immediately adjacent said locking barbs and acting against radially inward movement of said locking barbs, and said marginal surface engaging at least one of said barbs to lock said end closure onto said metal plate.

9. The combination in accordance with claim 8 wherein said locking barbs each extend through an arc of less than ten degrees.

10. The combination in accordance with claim 9 wherein said locking barbs each extend through an arc of not greater than three degrees.

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