This invention relates to pails and more particularly to means for uniformly orienting pails when nested in one another to form a stack.
Nestable containers are manufactured in a variety of forms for use in holding liquid and particulate materials. As a rule they have a frusto-conical shape, i.e., they have tapered side walls which may be flat or stepped. Making containers nestable so that they can be assembled in a stack reduces the amount of space required to accommodate them. This is advantageous in terms of reducing warehousing space costs. It also reduces shipping costs due the minimizing freight vehicle space requirements.
However, nested containers must be denested before being used or before being supplied to a station for filling with a liquid or particulate commodity, e.g., an asphalt composition for coating driveways, swimming pool chemical, fertilizer, detergent, or a foodstuff such as jam, peanut butter, margarine, etc. In many industries, the denesting operation is conducted automatically by machinery that is designed to denest containers one by one and present them to a conveying means for delivery to filling and capping equipment. A variety of such denesting equipment is exemplified by the following U.S. Pat. Nos. 6,764,273, issued Jul. 20, 2004 to K. Freudelsperger; 4,983,098, issued Jan. 8, 1991 to R. A. Heisler; 4,157,767, issued Jun. 12, 1979 to G. T. Schjedahl; 4,082,203, issued Apr. 4, 1978 to G. T. Schjedahl; and 3,795,346, issued Mar. 5, 1974 to T. V. Roberts et al.
A problem has existed with respect to denesting pails. As used herein the term “pail” means and denotes a nestable container having a pivotally mounted arched handle (usually called a “bail”). Although denesting equipment for pails is known (see, for example, U.S. Pat. Nos. 4,157,767 and 4,082,203, cited above), a problem has been encountered with denesting equipment in the case where the nested containers are not uniformly oriented in the stack that is to be denested, with the result that the handles of the nested containers are not aligned with one another. This non-alignment has tended to cause the denesting equipment to jam, misfeed or damage the containers. Damage to the non-aligned containers is particularly likely where the containers are made of a plastic material such as polyethylene.
The primary object of this invention is to provide a means for aligning the pails in a stack of nested pails so that their handles are aligned with one another, whereby to facilitate automatic denesting of the pails by operation of denesting apparatus.
Another object is to provide a means for interlocking a plurality of pails in a nested stack so that their handles are aligned with one another.
A further object is to provide a means for aligning a group of pails in a nested stack so that their handles are all aligned with one another, such means being characterized in that they place no substantial limitation on the size or ornamental design of the pails.
These and other objects are achieved by providing pails each having at least one peripheral flange projecting outwardly from its side wall, a radial slot in the peripheral flange displaced circumferentially from the pivot points of the pail handle, and a depending tab formed integral with and projecting from the side wall, with the tab being aligned with but displaced vertically from the radial slot so that when said pails are stacked the depending tab on one pail will be received by the radial slot in the next lower pail in the stack, whereby the handles of the stacked pails will be aligned with one another.
Other objects, features and advantages of the invention are set forth in or rendered obvious by the following detailed description of the invention which is to be considered together with the accompany drawings.
Turning to
Since the container is designed to be used as a pail, it is provided with two pivot anchors 20 for pivotally securing a handle 22. The two pivot anchors are diametrically opposed to one another. In the illustrated embodiment of the invention, each pivot anchor 20 comprises a pair of parallel mutually-spaced struts 24A and 24B and a short auxiliary side wall 26 that extends between those struts parallel to and spaced from container side wall 4. Struts 24A and 24b and side wall 26 extend between and are formed integral with flanges 14 and 16. Struts 24A and 24B also are formed integral with container side wall 4 and flange 16 is recessed between struts 24A and 24B. As a result each pair of struts 24A and 24B and the connecting side wall 26 define a pocket open at its lower end that accommodates the bent end 28 of the U-shaped portion of handle 22 Additionally each side wall 26 is formed with a hole 30 (
Turning now to
The container also is formed with a slot 36 in the first or top flange 12. Slot 36 is located in vertical alignment with the tab and has a width (the horizontal dimension as viewed in
A number of containers 2 may be stacked in nesting relation one on top of the other in the manner illustrated in
The invention has a number of advantages. For one thing the invention can be embodied in containers of different sizes and aesthetic designs. For another thing, the alignment tabs 34 and slots 36 do not unduly complicate the injection molding process. Most importantly, a stack of nested containers with their handle pivot anchors in mutual alignment as herein described and illustrated can be accommodated by de-nesting equipment without fear that a handle will be so misaligned as to cause malfunctioning of the de-nesting equipment or possible damage to the misaligned container. By way of example, the denesting equipment may be like the one shown in U.S. Pat. No. 4,082,203 (cited supra) where tine elements are used to elevate handles 22 in the denesting operation or like the one shown in U.S. Pat. No. 4,983,098 (also cited supra) where lug members engage protruding portions of the containers, e.g., the flanges 12 or 16, to effect separation. In this connection and with reference to
The invention may be practiced other than as described above and illustrated in the drawings. Thus, for example, the intermediate flange 14 could be eliminated. Alternatively the flange 12 could be eliminated and the slot 36 formed in flange 14. The latter modification may require varying the spacing between flanges 14 and 16 in order to assure that the tab 34 on one container will penetrate the slot 36 in the next lower container. It also is contemplated that each container may have more reinforcing flanges than the three flanges 12, 14 and 16, but in each case the slot will be in the uppermost reinforcing flange. It is also contemplated that the slot 36 may be formed in a radially-extending projection that is formed integral with side wall 4 but extends around the periphery of the container through an angle less than 360°. Another possible modification is to form the tab 34 as a separate member attached to and projecting from the side wall of the container instead of molding it as an extension of a circumferentially-extending flange, e.g., flange 16. Also the container may be formed with more than one aligning tab, with a slot 36 being provided for each tab.
Still other advantages and modifications of the invention will be obvious to persons skilled in the art.