US 3627170 A
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United. States Patent 72] inventors Dudley C. Pulliam;
Dana B. Bates, both of Seattle, Wash. [21 Appl. No. 857,753  Filed Sept. 15, 1969 45 Patented Dec. 14, 1971  Assignee Simpson Timber Company Seattle, Wash.
154 f CONTAINER 2 Claims, 4 Drawing Figs.
 US. Cl 220/60 R, ISO/0.5, 220/97 F  lint. Cl B65d43/l0, 865d 21/02  Field of Search 220/60, 97
c, 97 F, 97 R, 60 R; 229/43; 150/05 Primary Examiner-Ge0rge E. Lowrance At10rneySeed, Berry, Dowrey & Cross ABSTRACT: A plastic food container is provided with a straight walled top portion and a tapered bottom portion. The bottom portion terminates in a peripheral lip surrounding a concave bottom. The container has a removable top which is provided with a peripheral locking flange having an enlarged edge which snaps over an enlarged .rim on the container. The top is also provided with an accordion fold to allow upward expansion of the top. A plurality of spacers are provided on i i  Re mncesc the top which interlock with the peripheral lip of the bottom UNITED STATES PATENTS portion of the next container when the containers are stacked. 3.307.739 /1 7 C oy X A peripheral bead is provided on the top and engages a groove I in the top portion of the container for providing a seal. Ribs are provided to space the containers in a stack to allow air circulation.
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| ,1. his? 111111 Patented Dec. 14, 1971 INVENTOR. DUDLEY C. IPULLIAM DANA B. BATES ATTORNEYS CONTAINER 1. Field of the invention This invention pertains to containers, particularly of a type suitable for handling frozen foods, and to various features of containers which provide for stacking full containers, nesting empty containers, locking the tops on the container, providing for the expansion of frozen food within the container, and increase air circulation between containers.
2. Description of the Prior Art l-leretofore containers for frozen food, such as berries, have presented several problems for the food processing and shipping industries. One such container is the conventional cylindrical metal can. Metal cans are expensive, empty cans do not nest for storage, and since they abut adjacent cans along their entire lengths it is difficult to circulate a cold atmosphere between the cans for rapidly freezing the food therein.
Containers having tapered sidewalls, particularly plastic containers, have become more widely used; however, these containers also suffer from several drawbacks. Heretofore the tapered sidewalls of containers of adjacent stacks has caused the stack to be unstable causing an accordion effect which often tumbled the stack while being loaded or transported. To obviate this accordion effect the containers were provided with means to interlock the bottom of one container with the top of the next. This interlocking solution, however, conflicted with another phenomena occuring when freezing food in the containers. in the freezing of food, or other matter, the food at the outside of the container freezes before food at the center of the container. Thus a frozen torus of food is formed and since the torus has a greater volume when frozen than when in the unfrozen state it expands forcing the unfrozen or semifrozen food in the center of the container upwardly. This phenomena results in the top of the container bulging upwardly. Consequently, when tapered containers are stacked by interlocking the tops and bottoms of successive containers the bulging tops often unseat the next upwardly successive container again causing instability.
The bulging in containers used heretofore has also caused distortion over the entire top of the container often resulting in a loosening of the lock and seal between the top and the container.
Still another difficulty with heretofore-known containers is that there has not been an effective way to lock and seal the tops on the containers while permitting ease of removal of the tops from the containers without special tools. Still another difficulty has been that the tops of stacked containers have tended to ride together and lift each other off their respective containers when in transit.
SUMMARY OF THE INVENTION This invention pertains to a unique container for frozen and unfrozen foods and to various features usable with containers of general application other than for frozen foods. Typical of the frozen foods are berries, salad dressings, peanut butter, eggs. etc. Typical of unfrozen foods are syrups or the like which require that the top of the container have sufficient sealing capability to prevent the liquid from leaking out of the container.
It is a primary object of the invention to provide a container that utilizes a tapered sidewall but which provides a stable stack when several containers are placed on top of one another.
Another object of the invention is to provide a container top which may expand without distorting the peripheral sealing and locking edge thereof. A unique feature of the invention is also to provide a container with a concave or domed bottom which receives the expanded top of the next lower container in a stack.
Still another feature of the invention is to provide a container with a top which may be easily removed or locked onto the container and which provides a liquidtight seal.
Still another object is to provide a. container which allows free circulation of air between it and abutting containers.
Still another object of the invention is to provide a container which is inexpensive to manufacture, strong enough to withstand normal handling loads, and which is reusable for various other applications with or without the top.
BRIEF DESCRlPTlON OF THE DRAWINGS FIG. ii is a fragmentary elevation, partly in section, of a container embodying the principles of the invention.
FIG. 2 is a fragmentary plan of the container shown in FIG. ll.
E10. 3 is a fragmentary detail of the portion of the container shown in FllG. ll included in the circle 3.
MG. 4 is a schematic illustration of the containers in abutting stacks.
DESCRIPTlON OF THE PREFERRED EMBODIMENTS in general, the container lit) includes a top portion 112, a bottom portion M, a bottom 16, and a removable top 18. The entire container and top is preferably of plastic, such as an in jection molded polyethylene. The container may be of any size although for optimum capacity and handling for a product, such as frozen berries, a size capable of holding 30 pounds is preferred.
The top portion 12 of the container includes an encircling band of closely spaced vertical ribs 20. The vertical ribs provide a support surface for abutting against adjacent containers so that tipping is prevented. A circumferential boss 22 is provided above the vertical ribs 20 as a strengthening member and as an obstruction to reduce the possibility of the top of one container catching beneath the top of an adjacent con tainer.
For the purpose of locating the top 18 on the top portion 12 and for sealing the top on the container a circumferential groove 24 is provided in the inside surface of the top portion. The top 16 is provided with a circumferential bead 26 which engages in the groove 24 to seat and seal the top on the container.
The top portion 12 is provided with an upwardly extending, enlarged rim 26 having a downwardly sloping beveled surface 27 and a substantially horizontal locking ridge 28. The top 18 is provided with locking means which includes a locking channel 30 extending upwardly from the main body of the top. The locking channel terminates in a downwardly extending enlarged edge 32 having a beveled surface 34 and a substantially horizontal locking ridge 36. As is readily apparent to place the top on the container it is centered over the container and is pushed downwardly spreading the locking channel 30 as the beveled surfaces 27 and 34 slide over one another. When the locking ridge 36 0f the locking channel passes beyond the locking ridge 28 of the container rim the locking channel snaps back toward the center of the container providing a firm lock. The lock can be broken only by peeling the top from the container by starting first at one point on the circumference of the top and expanding the locking channel with an outward and upward movement. When in place the top fits onto the container a sufficient distance until the sealing bead 24 engages the groove 26. At this time the top is properly located on the container. Further lowering of the top as occurs when several containers are stacked thereon will lower the top even lower in the container forcing the sealing bead out of the groove 26 to form an even tighter seal between the top and the container. Downward movement is limited when the inside surface of the locking channel engages the top of the rim.
The top id is provided with a plurality of circular accordion folds 38 that encircle an expandable central portion 39. The purpose of the accordion folds 3b is to permit the frozen material within the container to raise the central portion 39 by elongating the folds. It is important to note that the distortion caused by the bulging central portion 39 is not transferred beyond the accordion fold and thus does not effect the lock or seal between the top and the container.
The expandable top also has an important role in stacking of containers. Thetop is provided with a plurality of circumferentially spaced spacers 40. The bottom portion of the container l4 terminates in a downwardly extending peripheral lip 42 which is adapted to engage and be slightly deformed by the spacers 40 when the bottom portion of a container rests on the next successively lower top 18. The spacers 40 are dimensioned to snugly engage the peripheral lip so that the upper container is held tightly by the lower top. The bottom 16 of the container is concave or domed for the purpose of accommodating the upward expansion of the central portion 39 of the top from the next successively lower container. In other words, the concave bottom 16 and the upwardly expandable central portion 39 of the top uniquely combine to provide a more efficient stack of containers for holding frozen food. Radial ribs 44 are provided on the bottom 16 as reinforcing members and also serve to allow circulation of cooling air between the bottom and top of the stacked containers. Additional radial ribs 45 are provided on the top 18 for the same purpose.
It is believed that the invention will have been clearly understood from the foregoing detailed description of my preferred illustrated embodiment. Changes in the details of construction may be resorted to without departing from the spirit of the invention and it is accordingly my intention that no limitations be implied and that the hereto annexed claims be given the broadest interpretation to which the employed language fairly admits.
The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. A container to be stacked with other containers for use in storing frozen fluid substances which expand while freezing comprising a top portion having an encircling band of vertical ribs, a tapered bottom portion terminating in an outwardly concave substantially rigid bottom. said top portion including an upwardly extending enlarged peripheral rim, a top fitted over said top portion and having a central portion surrounded by a peripheral locking channel, said locking channel including a downwardly extending lip having an enlarged edge, the diametrical dimension of the inside surface of said enlarged edge being less than the outside diametrical dimension of said enlarged rim, the outside surface of said enlarged edge being no greater than the diameter of said band of vertical ribs so that an abutting container cannot raise said top from the container, said locking channel being flexible so that said enlarged edge can fit over said enlarged rim and snap back to hold the top on the container, said top including a generally circular accordion fold in said central portion for allowing upward expansion of the top into the concave bottom of the next successive container stacked thereon, said accordion fold being 'located a substantial distance in from the locking channel of the top so that expansion occurs generally at the center of the top and thus in the vicinity of the greatest concavity of the bottom of said next successive container stacked thereon.
2. The container of claim 1 said central portion of said top being recessed downwardly below the upper edge of said peripheral rim and having an outwardly facing surface confronting the inwardly facing surface of said top portion, said confronting inwardly and outwardly facing surfaces having a mating circumferential bead and groove aligned when the top is on said top portion, said locking channel having limited downward movement when said top is on said top portion and wherein downward movement of said top due to the weight of a container stacked thereon will force the bead and groove to become misaligned providing a tight seal between the bead and the surface against which it abuts.
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