CARRIER WITH CUSHIONING PADS

Abstract

A pallet shaped carrier for manufactured article is made by thermoforming a single sheet of plastic so as to provide an array of cavities with walls and at least partial floors that may or not have drain holes. The carrier further comprises a plurality of injection molded cushioning pads with coin shaped body and stems with asymmetric retention barbs wherein the stems are inserted through strategically located holes in the walls and floors of the cavities.

Description

FIELD OF THE INVENTION

This invention is in the field of molded plastic carriers for manufactured articles and particularly carriers with strategically spaced cushioning pads to prevent direct contact between the manufactured articles and the walls and floors of cavities in the carrier.

BACKGROUND OF THE INVENTION

It is known to utilize pallets and other types of carriers, usually designed for compatibility with forklift trucks, to transport manufactured articles such as transmissions, axle housings, wheel bearings, and other articles of high precision quality from the point of manufacture to a point of assembly. It is important in the design of the carrier to protect the manufactured articles against damage due to rough handling of the carriers, as well as to prevent contamination of the articles with foreign material. Protection from damage can be accomplished through the use of dunnage materials such as Styrofoam pellets or granules and/or various other materials. It can also can be achieved by manufacturing the carrier in a complex, multi-sheet fashion so as to provide its own cushioning structure but this adds substantial cost to the carrier.

SUMMARY OF THE INVENTION

The present invention comprises a carrier for manufactured articles in which the carrier itself is a single sheet molded plastic article which can be easily and readily be made by thermoforming. The carrier, often referred to in the industry as “dunnage,” is structured so as to provide an array of cavities with walls and floors sized and shaped to receive specific manufactured parts. In addition, the carrier comprises a plurality of strategically arranged and pre-installed cushioning pads within the cavities to create a space between the carried parts and the walls and floors of the carrier. These pads minimize the risk of damage and eliminate potential part contamination.

According to the invention, each of the pads includes a coin or “button” shaped body of solid polymeric material with an integral stem extending along the axis of symmetry of the body. The body acts as a spacer and cushion when installed. The stem has at least two axially spaced asymmetric retention barbs formed integrally thereon at distances from the inside surface of the body that are correlated with the thicknesses of the materials in the various parts of the carrier such that, when properly installed by pushing the stem through a hole in the carrier wall or floor, at least one of the barbs operates to maintain the pad in the hole with the inner surface of the coin shaped body in contact with an interior surface of the wall or floor. The term “asymmetric retention barb,” means a barb with a sloped surface on the insertion side as hereinafter shown and described, such that the withdrawal force requirement is much greater than the insertion force requirement.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a representative pad from a first angle;

FIG. 2 is a perspective view of the pad from a second angle;

FIG. 3 is a side view of the pad showing illustrative dimensions;

FIG. 4 is a partial view of a carrier with multiple pads installed in walls and floor;

FIG. 5 is a partial view of the carrier with a part in a pad-cushioned cavity; and

FIGS. 6-8 are side views of a pad installed in carrier areas with three different material thicknesses.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT

Referring to FIGS. 1 and 2, there is shown an injected molded plastic pad 10 comprising a coined-shaped body 12 having an inside surface 12a that, in use, contacts a surface of the carrier in which it is installed. The body 12, as best shown in FIG. 2, also has a flat outside surface 12b which contacts the part to be placed in the carrier. The surface 12b is formed with a radiussed perimeter edge 12c as shown in FIG. 2

The pad 10 further comprises an integral stem 14 which is aligned with the axis of symmetry of the body 12. Formed integrally with the stem 12 are asymmetric retention barbs 16 and 18 at two different distances from the surface 12a to accommodate carrier wall thicknesses as hereinafter described. The end of the stem 20 is radiussed as shown is FIGS. 1 and 2.

As explained above the asymmetric retention barbs 16 and 18 have sloped upper surfaces as shown in FIG. 1 and flat bottom surfaces as shown in FIG. 2. As a result, the force required to insert the stem 14 of the pad 10 into and through a hole in the carrier wall or floor is less than the force required to withdraw the pad from the hole; i.e., the asymmetric barbs offer more resistance to withdrawal than they do to insertion as a result of the asymmetric configuration.

FIG. 3 shows an illustrative pad 10 in sectional view with representative or illustrative dimensions. The diameter of the coined-shape body or “button” can be 1.06 inches, while the radiussed edge 12c has a radius of 0.06 inches. The distance from the surface 12a to the flat inside surface of the barb 16 is 0.125″ while the distance to the bottom or flat surface of the upper barb 18 is 0.281″. The insertion angle of barbs 16 and 18 is approximately 45° but may lie in a range of about 35° to 45°. The radius of the top 20 of the stem 14 is 0.125″. The diameter of the barb 16 and 18 is 0.450″ while the diameter of the stem itself 0.250″. The thickness of the body 12 or the “button” can vary but in this example, is on the order of 0.125″. These dimensions are illustrative as they may all vary in accordance with the particular needs of the pad with respect to a given part and a given carrier.

FIGS. 4 and 5, illustrate a thermoformed polyethylene pallet-shaped carrier 22 for a precision machined part 28. The carrier has a number of cavities with walls 24 and floors 26 which receive pads 10 in strategic locations; i.e., there are four pads around the circumference of the walls 24 to cushion the part 28 in all directions and four pads 10 on the floor 26 to cushion the part 28 so that it does not touch any part of the floor 26. Because the carrier is essentially drawn into a mold, the material of the original sheet of plastic becomes thinner in some areas than in others.

FIG. 6 shows a pad 10 installed in a section 22a of the carrier 22 wherein the thickness of the material is such that the pad 10 may be inserted into the preformed hole in the material far enough as to cause the inside flat surface of the lower barb 16 to fully expand after insertion and lie flush against the surface of the material 22a.

FIG. 7, on the other hand, shows the pad 10 installed in a material section with a thicker dimension 22b which is not thick enough to reach the interior flat surface of the upper barb 18 but is too thick to allow full re-expansion of the lower barb 16. In these circumstances the lower barb is elastically deformed inwardly to create a retention force that holds the button in place.

FIG. 8 shows a material section 22c of maximum thickness; i.e., enough to fully deform the inner barb within the hole but allow the upper barb 18 to flex back outwardly to full diameter and place the flat inner surface flush against the surface 22c of the carrier. In all cases the pad is firmly held in place with the button or body 12 flush against the surface of the carrier wall or floor 22 which is on the inside of a cavity and, without the pad 10, would otherwise be directly contacted by the part.

There are numerous advantages to the invention. For one, all the pads 10 can be installed in the carrier cavities at any time prior to receiving the parts therein. There is little or no risk that the pads will separate from the carrier and be lost or thrown away as unwanted debris. Secondly, the pads 10 prevent the part 28 from directly contacting the material of the thermoformed carrier 22 and, particularly in the case of machine parts with sharp edges, the pads prevent the creation of unwanted debris shaved off of the inner surfaces of the cavities which debris could then contaminate the carried parts. Lastly, the buttons are useful to a considerable extent in preventing damage to the carried parts 28 as a result of inadvertent heavy contact between the carrier and a rigid object such as a trailer bed or forklift.

It is to be understood that the foregoing description is intended to provide full and enabling disclosure of the invention but is illustrative in the sense of specific details such as shape and dimensions and is not to be construed in limiting sense otherwise stated. The drawings, particularly FIGS. 1-3 and 6-8 are, however, to scale.

Claims

1. (canceled)

2. The carrier defined in claim 5 wherein the pads are made from a polymeric material.

3. The carrier defined in claim 2 wherein the polymeric material is injection molded polyurethane.

4. The carrier defined in claim 5 wherein the carrier body is thermoformed.

5. A carrier for manufactured articles comprising:

a body of molded plastic material having a cavity with an interior volume and formed integrally with said body, said cavity having a wall and a floor, each of said wall and floor having holes formed therein, at least two of said holes having different body material thicknesses;

a plurality of cushioning pads installed in said cavity holes;

each pad comprising a head portion and a stem integral with and extending from said head portion, each stem having at least two asymmetric retention barbs formed thereon at different distances from said head to secure said pad within a hole of any of said different body material thicknesses; and

the head of said installed pads lying within said interior volume to cushion an article placed within said cavity.