Nestable Container

Abstract

A container having means to prevent binding and rotation and provide positive engagement with adjacent nested containers. The bottom section of each container includes an upwardly offset center portion having teeth spaced around the top circumference inside each container. A corresponding set of teeth is provided around the bottom circumference of the center portion on the outer surface. When stacked, or nested, the bottom teeth of each container engage the top teeth of the container immediately below providing positive engagement without binding or rotation.

Description

The present invention relates to a one-piece container which may be conveniently stacked with like containers without damage or binding between the surfaces.

Previously, thin wall disposable plastic containers have been subject to binding and sticking when stacked or nested together. The larger the number of containers in each stack the greater the weight on the lower containers and thus the increased chance of binding. This most often results due to wedging effect by the side surfaces of one container against the lower container making it inconvenient to remove containers from the stack. In addition to binding, the engagement of adjacent side surfaces of conventional containers may result in undesirable scratching, particularly when the containers are rotated with respect to each other. Several attempts have been made to solve these problems. Such designs, however, have been unsuccessful, resulting in containers which are uncomfortable to hold and are more susceptible to tipping when set down.

It is an object of the present invention to provide containers which can be nested or stacked on top of each other, yet will not bind when removed from the stack.

It is a further object to provide a container which will not rotate with respect to the adjacent nested containers, thus preventing scratching.

It is another object of the present invention to provide a container which can be economically produced in a single piece and stacked with like containers, yet attractive in design, of reasonable strength, comfortable to hold in the hand, and not susceptible to tipping when set down.

It is a further object of this invention to provide containers which can be nested in large numbers with positive engagement and interlocking of the bottom portions of each container with very limited or no engagement of the side surfaces of adjacent containers, thus preventing scratching and damage as well as binding.

These together with other objects and advantages which will become subsequently apparent reside in the details of construction and operation as more fully hereinafter described and claimed, reference being had to the accompanying drawings forming a part hereof, wherein like numerals refer to like parts throughout, and in which:

FIG. 1 is a perspective view of the present container device.

FIG. 2 is a top view looking through the open end of the container device shown in FIG. 1.

FIG. 3 is a bottom view of the container device shown in FIG. 1.

FIG. 4 is a sectional view taken along the vertical plane of a pair of containers nested together.

FIG. 5 is an enlarged sectional view illustrating the interlocking surfaces of the pair of nested containers shown in FIG. 4.

Referring to the figures and more particularly to FIG. 1 thereof, the present interlocking container is indicated generally by numeral 10, and, preferably, is formed from a single piece of plastic in a way well known in the art. Thus the preferred embodiment is a one-piece, thin walled, disposable plastic container. It is comprised of a side wall structure 11 having an outer surface 12 and inner surface 13 and being generally frustoconical in shape, widening towards the opening at the top of the container. The vertical surface may be curved outwardly slightly as shown, if desired, to provide added strength and attractive appearance. It is not, however, essential that the vertical surface be curved, a pure frusto-conical surface or tapered variations thereof being within the scope of the present invention, so long as the geometry permits the interlocking and nesting as hereinafter described.

The container further includes a bottom portion, generally indicated by 14, having a substantially flat ring-shaped bottom surface 16 which is suitable for supporting the container in a stable position. The relative width of surface 16 may be greater or less than that illustrated dependent upon conditions and resting surfaces anticipated in the container's use. The greater the surface area 16, the greater will be the frictional resistance to sliding and the ability to rest on uneven surfaces. An indentation or offset portion 18 is formed in the center of the bottom portion and is substantially frusto-conical in shape having a central wall structure 20 which extends from opening 21 to a round upper member 22 thereby forming a sealed bottom in the container. The wall 20 may be sloped upwardly and inwardly as shown or it may be vertical or slightly offset from the vertical so long as the geometry permits nesting of the containers as hereinafter explained.

Referring to FIG. 4, it will be appreciated that the containers may be stacked or nested one inside of the other. The upper container 24 engages the lower container 26 at the circular tooth engaging area 28 in the bottom portions of each container. The side walls 11 of each container are shaped in such a way that they will not engage each other when the containers are properly aligned with each other in the nested position. Thus, there is a space or gap 29 between the top edge of lower container 26 and the outer surface 12 of container 24. This gap is ring-shaped when the containers are in perfect alignment. It is possible, that as the number of containers in a stack is increased, the stack may tend to lean to one side or another due to the unlevel surface upon which the containers are resting or to the inherent resiliency of the containers themselves. Under such conditions, the top edges of each container may engage the outer surface of the adjacent container over a relatively small area. When such does occur, the gap 29 is increased on the diametrically opposite side of each container thus maintaining a constant air space communicating with the interior 30 of the lower container. Such a configuration prevents the containers from becoming air locked with one another, wherein the air space of the lower container is sealed from atmosphere by the engagement of the upper surfaces when nested together. Air locking creates a vacuum between the two containers making removal of containers more difficult, since they tend to stick together. It will be appreciated that in the present invention the air space 30 of the lower container 26 is never sealed from the surrounding atmosphere even in the condition where the stack may lean to one side or another. Accordingly, the disclosed nestable container is not susceptible to sticking due to air locking or engagement of the side surfaces.

Each offset portion 18 includes two sets of teeth 32 and 34 spaced circumferentially around the upper and lower edges of the wall 20 to form a pair of circular serrated edges. The male teeth 32 are preferably formed at small angles to the vertical axis of the container while the female teeth 34 are formed at slightly greater angles to the vertical axis. Such a geometric configuration provides a set of positively interlocking teeth wherein alignment is aided by the offset surfaces 36 and 38 which slide over each other during the process of engagement. It is appreciated that since upper member 22 of the offset portion is relatively small in width and rigidly supported by wall 20, teeth 32 and 34 remain relatively rigid with respect to one another and are less likely to flex or bind as would the larger and more remote side walls 11. In addition, the serrated edges prevent relative rotation of the nested containers, thereby avoiding scratching of outer surfaces 12 by the top edge of each container should limited contact occur as hereinbefore explained.

It should be noted that slight variations in the configurations of the teeth forming the serrated edges are within the scope of the present invention. It is preferred, but not essential, that surfaces 36 and 38 be offset slightly as shown. Other teeth configurations, well known in the art, could likewise be used to achieve the interlocking result. Furthermore, the serrated edges on each container may be placed at slightly different locations on the container from that shown so long as they remain rigid with respect to each other and prevent binding.

It will be appreciated from the foregoing that a container has been provided which may be nested in large numbers without binding to each other. Furthermore, engagement of the outer surfaces has been limited, and rotation eliminated, thereby preventing scratching and possible cracking. It should be noted that, in the preferred embodiment, each container is made from a thin sheet of plastic by methods well known in the art, thus providing a one-piece disposable container which is economical to produce. It will be appreciated that the container of the present invention could be manufactured in a variety of ways or with several pieces and different materials if so desired.

The foregoing is considered as illustrative only of the principles of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation shown and described, and accordingly all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.

Claims

What is claimed as new is as follows:

1. A nestable container comprising a bottom portion, a side wall structure extending upwardly and outwardly from said bottom portion, said bottom portion including means for aligning the container in nested position with a similar container for preventing rotation therebetween, said means including an upwardly offset center portion comprising an opening, a central wall structure extending upwardly from said opening and an upper member connected to said wall to seal the bottom of the container, a male serrated edge including a plurality of male teeth extending around the perimeter of said central wall portion and disposed in the interior of the container, and a female serrated edge including a plurality of female teeth extending around the perimeter of said central wall structure beneath said male teeth and being disposed on the exterior of the container.

2. The nestable container set forth in claim 1 wherein each of said male and female teeth includes a plurality of upwardly extending male and female surfaces, each of said female surfaces being offset at an angle to each of said male surfaces with respect to the vertical axis of the container.