Edge protectors for insertion between a load to be lifted and a lifting element, such as a chain or wire cable of a crane, hoist or other lifting device, are well-known in the art. In addition, there are other devices specially-designed to protect the chain or wire cable of a lifting device from abrasion during a load lifting operation.
While these devices are useful to assist in the lifting of loads by means of a cable or other lifting device, improvements in such edge protectors are still necessary.
The drawings in detail
Referring more particularly to the drawings, the present invention comprises a wear pad (10) which is preferably formed as a generally cylindrical-shaped, edge protector (20) containing a cut out section removed from the cylindrical shape, as shown in Figs. 1 and 2, and first and second ends (24, 26), each of which contains an outwardly extending raised edge (28, 30) on the outside surface of the edge protector. Preferably a slot (32) is cut into the inside surface (22) of the cut out section, which extends from one end (24) of the edge protector to the other end (26) of the edge protector, preferably in the center of the cylindrical-shaped edge protector as shown in Figs. 1 and 2. Preferably an attachment element, such as a magnet (34), is secured to, or contained within, the inner surface of the cylindrical-shaped edge protector, preferably on or near the inside surface of the cut out section.
In operation, the inside surface of the cut out section of the cylindrical shaped edge protector is placed against the load. The lifting elements, such as a chain or wire cable of a crane, hoist or other lifting device, is then placed against the outside surface (36, 136, 236) of the edge protector (20, 120, 220) and tightly secured in position. The raised outside edges (28, 30, 128, 130, 228, 230) located at each end of the edge protector prevent the chain or wire from sliding off of the edge protector and also protect the chain or wire from abrasion during the load lifting operation. Once the load has been lifted to the particular desired location and the pressure is taken off of the chain or wire cable, the edge protector can be removed and reused.
The generally cylindrical shape of the wear pad can be formed in any size which will be useful as a wear pad for insertion between a load to be lifted and the chain or wire cable of a crane, hoist or other lifting device. The diameter of the generally cylindrical-shaped edge protector can be from about two inches to about two feet or more. The angle of the arc of the inside surface of this cut out section depends on its use. Preferably the angle of the arc ranges from about 45º to about 270º, preferably from about 45º to about 120º, and most preferably from about 60º to about 120º, as shown in Fig. 2.
When the inside surface of the cut out section is placed against the load, the chain or wire cable of the crane, hoist or other lifting device contacts the outside surface (36) of the cylindrical-shaped edge protector. This prevents the load from being damaged by contact with the chain or wire cable of the lifting device.
The ends (24, 26) of the cylindrical-shaped edge protectors (20) are preferably from about one inch to about four inches greater in diameter than the remaining diameter of the edge protector as shown in Figs. 1 and 3 and extend outwardly from the outside surface of the cylindrical shaped edge protector at least about one-half inch about two inches. These ends (24, 26) of the cylindrical-shaped edge protectors preferably extend outwardly a distance equal to or greater than a substantial portion of the diameter of the chain or wire cable of the lifting device. This structure has raised edges (28, 30) of the ends (24, 26) that extend outward from its outside surface that limits or prevents damage to the chain or wire cable in case the load impacts an object, such as a wall or column.
The cylindrical-shaped edge protector preferably contains a slot (32) running down the center of the edge protector at the point where the arms (38, 40) of the inside surface of the cut out section (22) meet, as shown in Fig. 1. One of the primary purposes of this slot is to relieve stress on the edge protector when in use. This slot (32) can be of any size and shape that accomplish this purpose. In one preferred embodiment this slot is circular in cross section and extends from one end (24) to the opposite end (26) of the edge protector as shown in Figs. 1 and 2. Its diameter can vary from one-quarter inch or more, as needed.
In a preferred embodiment an attachment element is secured inside the inside surface of the cut out section to attach the edge protector to the load being lifted. In one preferred embodiment this attachment element is a plurality of magnets (34), which are embedded into the surface (22) of the cut out section as shown in Fig. 1. Two or more magnets may be embedded in each arm (38, 40) of the edge protector, as desired. Other alternative attachments elements may also be used, such as hook and loop fasteners, or a bolt mechanism or other conventional attachment methods, as are known in the industry.
The edge protectors (20, 120, 220) are preferable formed from a high quality, durable plastic material, such as polypropylene. Preferably the product is injection molded in the desired shape.
