Abstract:
A stacking element is formed to engage two vertically stacked articles to hold the articles in position and is provided with projections on its external periphery to engage the projections on adjacent elements. These elements will maintain the articles in a stack against vertical and lateral displacement, so the stack will remain assembled during storage and transport.

Description:
GENERAL NATURE OF INVENTION 
     The stability of stacks of articles during storage and transport is assured by a simple, stacking element which is interposed between each two vertically adjacent articles. This element retains the articles against lateral shifting and also engages similar laterally adjacent elements to prevent shifting of the stacks, thus maintaining the stacks under all conditions. 
     In storage and transport of articles in stacks, especially in palletizing stacks for loading and unloading, the articles frequently shift so that the stacks collapse and the articles fall, resulting in delays and damage to the articles. The storage and movement of cans of paint is an example of this problem, the collapse of several tiers of stacked cans on a pallet often seriously damaging the cans and requiring substantial time to replace the cans for shipment. 
     To avoid this difficulty, it has been the partice to use sheet material, such as plywood, between the tiers and also as lateral spacers, thereby reducing the possibility of stacks falling over due to shifting of the cans. However, this use of sheet material is expensive, both for the sheets of plywood and for the handling of the sheets. Applicant&#39;s stacking elements are so inexpensive that they can be easily handled or discarded, and therefore do not involve problems for the shipper. They also are small and light, adding no significant weight and occupying little space. This element may be a molded plastic endless peripheral member to be seated on or fixed on one end of an article, such as a paint can, with a seat formed to receive the end of an adjacent, vertically stacked article, and formed with a peripheral series of lateral projections to engage similar projections on elements of laterally adjacent stacks. In this manner, the elements will hold the individual articles and the stacks from shifting and becoming disarranged. The stability of the stacks of articles makes the packaging of a group of stacked articles quite feasible, as, for example, with plastic foil applied to the stacked group, since the articles are retained against lateral displacement. 
    
    
     DRAWINGS 
     FIG. 1 shows stacked articles in phantom lines with the stacking elements of this invention between the articles of the stack. 
     FIG. 2 is a fragmentary cross section of the stacking element, showing the rims of vertically adjacent articles engaging the stacking element. 
     FIG. 3 is a fragmentary cross section corresponding to FIG. 2 of another form of stacking element. 
     FIG. 4 is a fragmentary cross section corresponding to FIG. 2 of a third form of stacking element. 
     FIG. 5 is a fragmentary view of two adjacent stacking elements, showing interengaging projections on the elements. 
     FIG. 6 is a fragmentary view of two adjacent elements, corresponding to FIG. 5, but showing a modified form of projection. 
    
    
     DETAILED DESCRIPTION 
     The stacking elements 10 of this invention, as shown in FIG. 1, engage stacked articles A to position the articles and maintain them in the stack. Each element 10 is in the form of a peripheral frame having a closed configuration to conform to the ends of the articles. The stacking element 10 has lateral or horizontal tabs or web 11 on its inner periphery with vertical shoulders or ribs 12, 13 to form seats for the top and bottom ends of article A, as shown in cross section in FIG. 2. The tabs or web 11 with the shoulders or ribs 12, 13 form seats to be engaged by vertically stacked articles to prevent relative shifting of the articles in the stack. 
     A continuous series of lateral projections or &#34;teeth&#34; 15 is provided on the external periphery of the stacking element 10 (FIG. 5) to engage corresponding projections on an adjacent stacking element and prevent lateral shifting of adjacent articles. As will be seen in FIG. 1, the stacking elements interengage with the articles and with the other stacking elements to hold the articles in position in the stack. 
     A modified form of stacking element 20 shown in FIG. 3 is formed for attachment to the articles. The stacking element 20 with the lateral tap or web on its internal periphery and the vertical shoulders or ribs 22, 23 may be snapped over the beads on the ends of the articles. A lateral protrusion or boss 26 on the internal side of each shoulder or rib extends over the bead A&#39; on the article, so that the stacking element 20 may be attached to the article by forcing the protrusion or boss 26 over the bead, which is received in a recess 27 on the periphery of the element 20. The resilience or flexibility of the material of the element 20 will allow the element to be distorted sufficiently to allow the protrusion 26 to be forced over the bead A&#39; by starting at one side and engaging it with the bead and continuing around the bead of the article. This attachment of the stacking element to the articles provides further stability to the stack of articles. 
     The stacking element may also be formed with a vertical rib or shoulder to fit within the end of an article, as shown in FIG. 4, which also shows the element attached to the article. In this form, the stacking element 30 with vertical shoulder 32, 33 is also provided with an inwardly spaced, vertical rib 34 which fits within the rim or bead A&#39; of the article A. This vertical rib 34 also carries a laterally projecting lip 37 which underlies the edge of a lid B, when the lid is in position to close the container A. The stacking element is thereby connected securely to the container A and retained therewith. In this form, the upper article A may have a snap engagement with the stacking element, as in FIG. 3. 
     All forms of the stacking element are provided with external projections to engage corresponding projections on adjacent elements. These projections may be those shown in FIG. 5, or they may be of the form shown in FIG. 6. The projections 41 are wider at their outer ends than at their bases, with the spaces 42 between of complementary shape. As seen in FIG. 6, the projections of adjacent stacking elements interengage to prevent relative movement, the material of the element being flexible to allow interengagement of these projections. 
     The stacking elements of this invention will retain a number of articles in stacked relation, both vertically and horizontally. These elements may be easily molded of plastic material, which has sufficient flexibility to enable the elements to be engaged with the articles, as in FIG. 3, and may also interengage with other elements, as in the form shown in FIG. 6. The stacking element may also engage the external periphery of the article, as shown, or may also engage internally of a rim on the article, as in FIG. 4. Containers such as paint cans may be held by the stacking elements, and these elements may be attached to the cans, as in FIG. 4. While shown for paint cans in this one form, it will be recognized that the stacking elements may be designed to engage articles of circular, polygonal or other shapes.