Pallet having crowned cross rail
A molded plastic pallet, connects opposing sides of the pallet bottom, has a cross rail that has a crowned surface. Thus, should the wheels of a pallet jack rest on the surface of the rail as the jack's fork prongs are inserted under the pallet, they will be urged to roll off the rail, to avoid damage to the pallet which could occur when the jack lifts the pallet.
This application claims benefit of U.S. Provisional Patent Application No. 60/655,792, filed Feb. 23, 2005 and is a continuation-in part of U.S. patent application Ser. No. 10/729,615, filed Dec. 5, 2003, which is a divisional of U.S. patent application Ser. No. 09/938,954, filed Aug. 24, 2001, now U.S. Pat. No. 6,705,237, which claimed priority to U.S. Provisional Patent Application Ser. No. 60/227,537, filed Aug. 24, 2000, the entire contents of each of which are specifically incorporated herein by reference.
TECHNICAL FIELDThis disclosure relates to a device for the transportation of packaged goods, and, more particularly, to a pallet that meets certain standards set by the Grocery Manufacturers Association (GMA) and others for weight, durability, and strength.
BACKGROUNDThe present disclosure relates to improvement in pallet cross rails, and in some embodiments to an improvement useful on the pallet invention described in U.S. Pat. No. 6,705,237 and any other pallet having analogous features referred to below. In a pallet made in accord with the aformentioned patent, metal beams are embedded in the thermoplastic base of the pallet, which lie along the path of a rectangle neat the outer edges of the pallet. There are other metal beams at the base elevation, which act as rails, connecting opposing sides of the base and intersecting at the center of the pallet. They lie along the plane of the surface upon which a pallet typically rests during use for carrying goods; and they provide strength to the pallet.
One of the problems relating to any pallets, and shared by plastic pallets, relates to the use of hydraulically powered pallet jacks, also called pallet hand trucks, referred to here simply as jacks. Typically, jacks are wheeled, manually powered devices which lift a pallet an inch or more off the ground, so that the pallet can be transported a short distance by pulling the jack by its handle, by rolling the jack with pallet along a warehouse floor or the like. A typical jack has two spaced-apart fork prongs which raise and lower vertically, usually under action of a manual hydraulic pump, when the fork prongs are positioned under the pallet. See U.S. Pat. No. 3,982,767 for a fuller description of a jack. In use, the jack is positioned beneath a pallet, essentially by inserting the jack fork prongs into the side openings of a pallet, where forks of a powered fork lift otherwise enter. The typical jack has a wheeled carriage, relative to which the fork prongs move up and down. The carriage has wheels in vicinity of the outer ends of the fork prongs. Thus, to insert the fork prongs under the pallet, when the jack is in its collapsed or minimum height position, the wheels must pass over the any rail which connects the opposing edges of the pallet.
In wooden pallets, the edges of such rails are often beveled to make easier the motion of the wheels as they “bump” over the rail. Even so, a certain amount of rough force is usually employed by the jack operator to position the jack. With a conventionally dimensioned pallet, when a jack is fully inserted, the end wall of the jack contacts the near-edge of the pallet, and the outer-end wheels of the carriage are appropriately positioned, so they rest on the floor between any center rail and the far-edge rail. Thus, when the operator lifts the fork prongs, they lift the pallet and it is supported by the outer end wheels and the inner end wheels of the jack carriage, which are outward from the near-edge of the pallet.
It is a problem that, when jack operators are uncaring or there is some difficult access situations, the jack may be only partially inserted, and one or both wheels can rest on a rail. When the fork prongs are then lifted, there is force between the rail and the upper deck of the pallet, and the pallet can be pushed apart and in fact destroyed. Because plastic pallets can cost substantially more than wood pallets, such errors become more economically consequential, and thus it is an aim to prevent the bad event.
SUMMARYThe above described and other problems and disadvantages of the prior art are overcome and alleviated by the present pallet having one or more rails, which rails run along the floor and connect opposite sides of the pallet, wherein one or more cross rails have a top surface that is crowned. In such embodiments, if the wheels at the outer end of a pallet jack are improperly positioned so that they rest on the cross rail, they are urged by the crown shape and gravity to roll off the cross rail. In alternate exemplary embodiments, the crowned surface may be a curve with the apex at the center of the cross rail, or the crowned surface may comprise one or more sloped planar surfaces.
The foregoing and other objects, features and advantages of the present pallet will become more apparent from the following description of exemplary embodiments and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGSReferring now to the accompanying FIGURES, which are meant to be exemplary and not limiting:
As described above, the present disclosure relates to pallets having crowned interior cross rails, which rails run along the floor and connect opposite sides of the pallet. The rails run transverse to the length direction of the fork prongs of a fork jack inserted under the pallet for transport.
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A rail in accordance with those disclosed herein may have vertical edges 48, as shown in
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With regard to any of the embodiments, any amount of rise of a crowned surface, or height of a center apex of the crowned surface, of a rail is contemplated, as long as the height is not such that the carriage or fork prongs would hit the underside of the top deck or portions of the frame.
While the crowned cross rails are especially useful for plastic pallets (due to the cost, moldability, reinforceablity, etc. of plastic constructions), it may of course also be applied to pallets made of other materials, including wood pallets. Without being limiting, a pallet having a plastic construction may be made of polyethylene, polypropylene or other thermoplastic in alternative ways and with alternative configurations.
Although this invention has been shown and described with respect to a exemplary embodiments, it will be understood by those skilled in this art that various changes in form and detail thereof may be made without departing from the spirit and scope of the claimed invention.
Claims
1. A pallet, comprising:
- a cross rail configured to run along a portion of the floor or other surface to connect opposite sides of the pallet, wherein the cross rail has a crowned top surface.
2. A pallet in accordance with claim 1, wherein the crowned top surface comprises a curved surface.
3. A pallet in accordance with claim 2, wherein the curved surface has a maximum height between the edges of the cross rail.
4. A pallet in accordance with claim 1, wherein the crowned top surface comprises at least one surface angled relative to a horizontal.
5. A pallet in accordance with claim 1, wherein the crowned top surface comprises two surfaces angled relative to a horizontal, wherein an apex of the surfaces lies midway between the edges of the cross rail.
6. A pallet in accordance with claim 1, wherein the crowned top surface comprises a plurality of surfaces angled relative to a horizontal.
7. A pallet in accordance with claim 1, wherein the cross rail has at least one vertical edge.
8. A pallet in accordance with claim 1, further comprising a second, non-crowned cross rail positioned as an outer pallet rail, wherein the crowned cross rail is an inner cross rail.
9. A pallet in accordance with claim 8, wherein the inner cross rail has at least one vertical edge that is about the same height of the outer cross rail.
10. A pallet in accordance with claim 1, wherein the crowned cross rail includes at least one recessed lower surface.
11. A pallet in accordance with claim 1, wherein the cross rail comprises a plastic cross rail.
12. A pallet in accordance with claim 11, wherein the cross rail comprises a plastic cross rail having a metal reinforcing beam.
13. A pallet in accordance with claim 1, wherein a frame, base or deck portion of the pallet comprises a plastic.
14. A pallet in accordance with claim 13, wherein a frame, base, or deck portion of the pallet comprises a polyethylene or a polypropylene material.
Type: Application
Filed: Feb 23, 2006
Publication Date: Jan 18, 2007
Inventor: Roy Moore (Killingworth, CT)
Application Number: 11/360,553
International Classification: B65D 19/38 (20060101);