US3840143A

US3840143A - Threaded nestable container

Info

Publication number: US3840143A
Application number: US00235942A
Authority: US
Inventors: P Davis; G Fong
Original assignee: Sweetheart Plastics Inc
Current assignee: SWEETHEART PROPERTIES Inc; Solo Cup Operating Corp
Priority date: 1970-02-10
Filing date: 1972-03-20
Publication date: 1974-10-08
Anticipated expiration: 1991-10-08

Abstract

A thin-wall one-piece plastic nestable container having a threaded section adjacent its top and with a nesting facility in the side wall having a greater axial extent than the threaded section, and having a top edge smaller in diameter than the threaded section.

Description

United States Patent 11 1 Davis et al.

1451 Oct. 8, 1974 I THREADED NESTABLE CONTAINER [75] Inventors: Paul Davis, Swampscott; Gim'P.

Fong, Newton, both of Mass.

[73] Assignee: Sweetheart Plastics, Inc.,

Wilmington, Mass.

[22] Filed: Mar. 20, 1972 [21] App]. No.: 235,942

Related U.S. Application Data [63] Continuationimpart of Sen No. 10,227, Feb. 10,

' I970, abandoned.

[521 U.S. 'Cl. 220/39 R, 220/40, 220/97 C y' [51] Int. Cl... B6Sd 41/04, B65d4l/06, 865d 21/00 [58] Field of Search 220/39 R, 40, 97 C, 97 F;

[56] I References Cited UNITED STATES PATENTS 2,707,588 5/l955 Amberg 229/].5 B

4/l964 Sherlock ..220/39R 3,l28,005 3.139.213 6/1964 Edwards; ..220/9"/c 3,510,023

5/1970 Ullman 220/60 R FOREIGN PATENTS OR APPLICATIONS 688,808 6/1964 Canada; ..220/39R 247,863 8/1959 Australia; ..21s/44 Primary Examiner-George E. Lowrance;

Attorney, Agent, orFirm-Wolf, Greenfield & Sacks [57 ABSTRACT A thin-wall one-piece plastic nestable container hav- I ing a threaded section adjacent its top and with anesting facility in the side wall having a greateraxial extent than the threaded section, and having a top edge smaller in diameter than the threaded section.

, 17 Claims, 9- Drawing Figures PATENTEB UB7 8 I374 sum 20F 3 FIG. 3

FIG. 5

PATENTED BET 81974 SHEETS!!! 3 bodiment of this invention;

THREADED NESTABLE CONTAINER RELATED APPLICATION This application is a continuation-in-part of applicants copending application Ser. No. 10,227 filed Feb. 10, 1970, now abandoned.

This invention relates to nestable containers and more particularly comprises a new and improved nestable container having a threaded section for receiving a cover all-type screw cap.

At the present time glass jars are universally used in the food industry for packaging foodstuffs. These jars are not only expensive but they are uneconomical to handle and store. Ordinarily they are shipped by the manufacturer to the food processor in cartons, packaged in tiers, and they consume as much space empty as fulljlt is evident that perhaps times as much space is consumed in stacking individual glass jars of that type in cartons in unnested relationship as is required to store the same number of containers made of thin wall plastic, which nest closely together.

One important object of this invention is to provide a thin wall one-piece plastic container having a threaded mouth and which may be nested in close relationship with other like containers.

Another object of this invention is to provide a onepiece, formed, plastic thin-wall container which is threaded to receive a standard pitch cover-all screw cap of metal, plastic or other suitable material.

Yet another important object of this invention is to provide a container having a combination nesting facility and threaded mouth, and which has a smooth readily printable outer surface throughout substantially its whole axial height. 7

To accomplish these and other objects, the container of this invention in its preferred form is provided with a threaded section at its upper end which section also serves as a nesting ring. The surface on which the threads are formed is defined at its extremes by the top edge of the container and a lower shoulder, which cooperate to serve as mating components when identical containers are nested together. The axial height of the nesting facility is slightly greater than the axial extent of the threads so that the containers, when stacked,

nest with their threads exposed so as not to interfere with other containers in the stack.

In the drawings:

FIG. 1 is an exploded side view ofa container and lid constructed in accordance with this invention;

FIG. 2 is a side view of a stack of nested containers identical to the container shown in FIG. 1;

FIG. 3 is a fragmentary cross sectional view showing the container and lid of FIG. 1 in threaded engagement;

FIG. 4 is a fragmentary cross sectional view showing another embodiment of container and lid constructed in accordance with this invention;

FIG. 5 is a fragmentary cross sectional view of two nested containers identical to the container of FIG. 4;

FIG. 6 is a side view of a stack of nested containers constructed in accordance with another alternate em- FIG. 7 is a fragmentary cross sectional view taken through line 77 of FIG. 6;

FIG. 8 is a side view of still another alternate embodiment of containers in accordance with this invention; and,

FIG. 9 is a cross sectional view through the container of FIG. 8.

The embodiment of this invention shown in FIGS. l-3 includes a container C having a side wall 10 and integral bottom wall 12 formed of thin plastic sheet, of generally uniform thickness. Typically the material may be polystyrene or other thermoplastic having a stock thickness of .020 to .090 inch before forming. Generally, larger containers have a greater wall thickness than smaller containers. It is to, be understood that the wall thickness while generally uniform varies from one location to another caused by the stretching of the plastic if it is vacuum or pressure formed.

The container C is designed to threadably receive the lid L which is of conventional design, made of metal or some similarly rigid material and used as a cover-all screw cap on a very wide variety of food containers. The side wall 10 of the container C has an upper section 14 and a lower section 16, and the upper section 14 is threaded to accommodate the lid L.

The upper section 14 is defined by a lower shoulder 18, an upwardly and inwardly tapered intermediate wall 20 and a rim 22 which has little or no outward flare so that its diameter is smaller than the minimum inside diameter of the skirt of the lid L, as described in greater detail below. As shown in FIG. 2, the upper section 14 serves as a nesting ring. When a plurality of such containers are telescoped together as in FIG. 2, the lower shoulder 18 of one container rests upon the rim 22 of the next lower container in the stack. The outer diameter of the shoulder 18 measured at its greatest point exceeds the inner diameter of the rim 22 by more than twice the stock thickness. This increased interference between the diameters of the rim and shoulder assure proper nesting of the containers without jamming. This intermediate wall 20 may typically be upwardly and inwardly inclined at an angle of 2 to the vertical. The greater the inclination of the wall 20, the greater the interference for a given height of nesting ring. While the embodiment shown has an upwardly and inwardly tapered intermediate wall 20 to assure proper nesting,

-it is to be understood that with relatively large stock thicknesses, the intermediate wall may be vertical, as the stock thickness interference may be adequate for proper nesting.

Threads 24 are provided on the intermediate wall section 20 and are interrupted as is clearly evident in the drawings, with each section of the threads describing an arc of approximately 24. The thread 24 is interrupted as shown to facilitate stripping of the container from the mold in which it is formed. If the thread 24 were continuous, it would be more difficult to strip the container from the mold because of the continuous interference between the thread itself and the undercut provided in the mold for forming the thread. With the interruption, the wall maybe somewhat more yieldable radially, and thestraight section 25 between adjacent segments of the threads may provide axial stiffness to the upper section which is also desirable to achieve a good seal between the container andv lid. However, in certain applications a. continuous thread may be satisfactory. g 1

In FIG. 1 it will be noted that the rim 22 is trimmed very close to the plane of the outer surface of the intermediate wall section. It is essential that the rim 22 be trimmed very close to the plane of the wall so as not to interfere with the application of the lid L to the container. The interrupted threads 24 play an important part in allowing the trimming tools to get close to the side wall to achieve the close trimming as illustrated.

The lid L which is of standard design has a top wall 30 and a skirt 32. The skirt 32 is provided with the continuous thread 34 which mates with the threads 24 on the intermediate wall section 20. The pitch of the thread 34 mates with the pitch of the thread 24 so that the cap may readily be turned on the intermediate wall section to lock the lid L in place. Preferably the lid L is provided with a standard gasket 36 cemented or otherwise secured to the periphery of the top wall 30, which gasket engages the rim 22 to form a tight seal about the container mouth when the lid is screwed to the container. The gasket 36 functions in the same manner as with' glass containers, but the thinness of the rim 22 may provide a better seal between the gasket and rim.

The outer surfaces of the threads 24 generate a cylinder about the intermediate wall 20 of upper portion 14 of the container side wall 10. Because the intermediate wall 20 is inclined upwardly and inwardly, in order for the threads to generate a cylinder the radial height of the threads must increase as they approach the rim 22 from below. In order to get maximum gripping engage ment between the lid and container the threads 24 must be cylindrical, rather than decrease in height from bottom to top as would be the case if the thread height followed the inclination of intermediate wall 20.

While the container shown in FIGS. 1-3 is made of thin stock plastic material and therefore is quite flexible, it possesses sufficient rigidity to bind tightly within the lid L when they are screwed together. Whatever limitation may exist because of its thin material, the stiffness of the container is of course enhanced when it is filled particularly with a solid or semi-solid material such as peanut butter, etc. The contents of the container itself lends rigidity to the container walls, and the fit between the container and lid particularly when the container is full is comparable to the fit between such a lid and a glass container of comparable size.

In the preferred embodiment shown in FIGS. 1-3 the upper section 14 of the side wall may be approximately 7/l6 inch in height, and the remaining portion of the side wall, namely lower section 16 is uninterrupted so that it may bear advertising material, copy, a design or trademark, or other indicia. It is most desirable that the side wall of the container be uninterrupted over a maximum portion of its total height so that it may accommodate as much printed material as is desired. By combining the threaded section with the nesting ring, maximum space is made available for printing. In the embodiment of FIGS. 4 and some of that space is sacrificed by separating the nesting ring and the threaded section. Thus, in the embodiment of FIGS. 4 and 5 the container includes a side wall 40 and a bottom wall 42, and the side wall 40 includes a lower nesting ring 44,

an upper threaded section 46, and a central portion 48 which is available for printing. In this embodiment the threaded section 46 is composed of a generally cylindrical wall 50 bearing threads 52 on its outer surface. Like the preferred embodiment, the threads 52 are in-' terrupted tofacilitate stripping of the container from the mold. The rim 54 is trimmed very close to the plane of the outer surface of the cylindrical wall 50 so as not to interfere with the application of the lid L to the container. The lid L shown in FIG. 4 is identical to the lid L in the preferred embodiment.

So as to assure that the thread 52 does not interfere with the nesting of the container, the pitch of the nesting ring 44 is greater axially than the axial extent of the threaded section 46. The stacking ring 44 includes a lower shoulder 56 which is contiguous with the bottom 42, an upper shoulder 58, and an intermediate wall section 60 which is upwardly and inwardly inclined. The containers of FIG. 5 nest with the lower shoulder 56 of one container sitting on the upper shoulder 58 of the next lower container in the stack. When so nested, the cylindrical section 46 of each container lies outside the next lower container in the stack so that its threads 52 do not bind on the side wall of the next lower container and cause them to stick together. Ifthe nesting ring 44 were of lesser axial extent than the threads 52, the threads 52 of one container would lie below the rim of the side wall of the next lower container in the stack, and containers could bind upon the side wall of the next lower container to make separation of the containers difficult.

As in the first embodiment, the threads 52' generate a cylinder about the upper section 46 of the side wall to assume maximum engagement with the threads in the cover. If the upper wall section 46 is other than cylindrical, the threads 52 should be of varying radial height to compensate for it.

In the embodiment of FIGS. 6 and 7, the container 61 embodies the principles of container C of FIG. 1. Thus, the thin wall thermoplastic side wall 62 corresponds to side wall 10 and has an upper section 63 and a lower section 64. The side wall 10 has a constant taper from an upper rim 65 to a rounded bottom corner 66. A conventional raised bottom 67 closes the end of the container 61.

Instead of a single interrupted thread 24, the container 61 has a quadruple continuous thread arrangement of

thread portions

68,68, 69 and 69' with all the thread portions being of the same pitch but spaced from each other.

In this embodiment, the threaded section adjacent the top of the container is formed by the upper section 63. As best shown in FIG. 7, the lowermost part of

thread portions

68, 68', 69 and 69' form lower shoulders 70 corresponding to shoulder 18 of container C and acting as a nesting facility when the cups 61 are stacked. Thus, the shoulders 70 which are in effect an interrupted stacking shoulder. rest on the stock thickness at the rim 65 of an underlying container.

The

thread portions

68, 68, 69 and 69 are engagable with standard lids such as lid L modified to have quadruple interrupted or uninterrupted threads.

In some cases, a single interrupted thread or a single uninterrupted thread can be formed in a container such as 61 in place of the

threads

68, 68, 69, 69'. Interrupted threads are preferred as described above.

The embodiment of FIGS. 8 and 9 illustrates a container identical to container 61 except that the threads are replaced with a single interrupted thread 81 extending in six portions radially outwardly from the circular upper wall section 63. In this embodiment, container parts identical to corresponding parts of container 61 are given the same numbers primed.

As shown in FIG. 9, the lower edge 82 of the lowermost thread portion forms the nesting shoulder which rests on the stock thickness of the rim 65. A flared rim can be used if desired but must be trimmed to be noninterferring with a conventional lid L as described above.

In the embodiments of FIGS. 6-9, the nesting facility is formed by the side wall extending from the bottom shoulder of the lowermost thread portion vertically up to the rim 65 and thus has an axial extent at least as great as the axial extent of the threaded section.

It should be noted that where a single interrupted thread 81 is used, the stacking or nesting shoulder 82 is in essentially point contact with the rim 65 of the underlying container in a stack. However, even this contact is sufficient to provide good stacking without substantial misalignment of a stack of containers since the constant taper side walls below the threads of two adjacent containers are spaced close together and engage if necessary to prevent substantial misalignment in a stack.

In each embodiment, a threaded container is provided which stacks in nested relationship with other identical containers so that a maximum number of containers may be stored when empty in a given volume. It is evident that this type of stacking arrangement provides a tremendous advantage over' the non-nesting character of the widely used glass containers in the food industry. Not only are the containers substantially less expensive than those made of glass, but they are easier to handle, lighter in weight, more readily disposable, much more easily stored, and less apt to break. While thermoformed containers are preferred, the structures of this invention can be formed by other conventional plastic molding methods such as blow molding and injection molding. In all cases, the wall thickness of the containers is preferably within the range of from .015 to .090 inch.

What is claimed is:

l. A thin wall, one-piece, plastic, nestable container comprising a bottom wall and a side wall integral therewith, with the walls of generally uniform thickness, said side wall having a lower section and an upper threaded section that forms an upwardly extending continuation of the lower section,

said threaded section having a circular wall on which a thread is formed which extends radially out from the wall, the top of said threaded section terminating radially very close to the top of the circular wall and with the container being free of an outwardly and downwardly extending rim structure that would interfere with the threading of a lid onto the threaded sectron, and a nesting facility formed in the side wall and having an axial extent at least as great as the axial extent of the threaded section whereby the threaded section of the container lies above the top of the threaded section of a like container nested below It,

said nesting facility being formed in part by said circular wall of the threaded section and defining a nesting shoulder below said thread and a nesting top above said thread.

2. A thin wall, one-piece, plastic, nestable container as described in claim 1 further characterized by said thread being interrupted. 3. A thin wall, one-piece, plastic, nestable container as described in claim 1 further characterized by said circular wall being tapered upwardly and inwardly and comprising the intermediate wall of the nesting facility, and an outwardly extending shoulder in the side wall defining the lower extremity of the threaded section and said shoulder of the nesting facility and which sits on the top of the side wall of a like container nested below. 4. A thin wall, one-piece, plastic, nestable container as described in claim 3 further characterized by the radial extremity of the crown of the thread generating a cylinder. 6. A thin wall, one-piece, plastic, nestable container as described in claim 5 further characterized by said top being trimmed close to the plane of the cir-' cular wall so as to lie well within the radial extremity of the crowns of the thread.

7. A thin wall, one-piece, plastic, nestable container as described in claim 6 further characterized by said thread being interrupted.

8. In combination with the container of claim 1, a coveralllid fitting over the container top and having a downwardly extending skirt internally threaded and screwed onto the threaded section of the container.

9. In combination with the container of claim 7, a coverall lid fitting over the container top and having a downwardly extending skirt internally threaded and screwed onto the threaded section of the container.

10. A container and lid combination as described in claim 8 further characterized by the lid having a continuous thread.

11. A container and lid combination as described in claim 9 further characterized by the lid havinga continuous thread.

12. A thin wall, one-piece, plastic, nestable container as described in claim 1 further characterized by said thread defining said nesting shoulder as a portion thereof.

13. A thin wall, one-piece, plastic, nestable container as described in claim 12 further characterized by said upper and lower side wall sections having a uniform taper.

14. A thin wall, one-piece, plastic, nestable container as described in claim 12 further characterized by said thread being interrupted.

15. A thin wall, one-piece, plastic, nestable container as described in claim 14 further characterized by the radial extremity of the crown of the thread generating a cylinder.

16. In combination with the container of claim 14, a coverall lid fitting over the container top and having a downwardly extending skirt internally threaded and screwed onto the threaded section of the container.

17. A thin wall, one-piece, plastic, nestable container as described in claim 12 further characterized by a plurality of threads being formed on said threaded section 'and extending radially outwardly therefrom.

Claims

1. A thin wall, one-piece, plastic, nestable container comprising a bottom wall and a side wall integral therewith, with the walls of generally uniform thickness, said side wall having a lower section and an upper threaded section that forms an upwardly extending continuation of the lower section, said threaded section having a circular wall on which a thread is formed which extends radially out from the wall, the top of said threaded section terminating radially very close to the top of the circular wall and with the container being free of an outwardly and downwardly extending rim structure that would interfere with the threading of a lid onto the threaded section, and a nesting facility formed in the side wall and having an axial extent at least as great as the axial extent of the threaded section whereby the threaded section of the container lies above the top of the threaded section of a like container nested below it, said nesting facility being formed in part by said circular wall of the threaded section and defining a nesting shoulder below said thread and a nesting top above said thread.

2. A thin wall, one-piece, plastic, nestable container as described in claim 1 further characterized by said thread being interrupted.

3. A thin wall, one-piece, plastic, nestable container as described in claim 1 further characterized by said circular wall being tapered upwardly and inwardly and comprising the intermediate wall of the nesting facility, and an outwardly extending shoulder in the side wall defining the lower extremity of the threaded section and said shoulder of the nesting facility and which sits on the top of the side wall of a like container nested below.

4. A thin wall, one-piece, plastic, nestable container as described in claim 3 further characterized by said thread being interrupted.

5. A thin wall, one-piece, plastic, nestable container as described in claim 1 further characterized by the radial extremity of the crown of the thread generating a cylinder.

6. A thin wall, one-piece, plastic, nestable container as described in claim 5 further characterized by said top being trimmed close to the plane of the circular wall so as to lie well within the radial extremity of the crowns of the thread.

8. In combination with the container of claim 1, a coverall lid fitting over the container top and having a downwardly extending skirt internally threaded and screwed onto the threaded section of the container.

11. A container and lid combination as described in claim 9 further characterized by the lid having a continuous thread.

17. A thin wall, one-piece, plastic, nestable container as described in claim 12 further characterized by a plurality of threads being formed on said threaded section and extending radially outwardly therefrom.