Handling: hand and hoist-line implements – Hook – hoistline – or grab type
Reexamination Certificate
2000-12-20
2002-08-06
Cherry, Johnny D. (Department: 3652)
Handling: hand and hoist-line implements
Hook, hoistline, or grab type
Reexamination Certificate
active
06428069
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates generally to a tool for hooking pallets or skids, and more particularly, to a pallet hook for repositioning two-way and four-way stringer pallets.
2. Description of the Art
Goods and materials arrive at, and depart from, almost every type of factory or warehouse by unit loads on material handling devices which are typically pallets. A unit load is a number of items, arranged and restrained as one unit on a support platform, so as to be moved and handled at one time, thereby reducing the number of trips required to load/unload items, and consequently reducing handling costs and product damage. In addition to facilitating the efficient handling of large quantities of materials, pallets also serve as a platform base for stacking individual items.
Conventionally, every pallet contains a top deck and bottom deck of wood slats running parallel to each other. Stringers (or runners), which are solid or notched beams running perpendicular to the slats comprising the decks, separate the two decks. In a typical two-way stringer pallet, there are three stringers. The stringers, identified by location, define two chambers between the outside stringers and the interior, or center stringer. The chambers provide the openings for the fork tines of a lift truck or hand jack. The term “two-way” indicates that the fork lift can be inserted from either the front or the back of the pallet. In a four-way pallet, the stringers are notched for entry from all four directions. Skids, of course, are pallets with only an upper, or top, deck.
It is a problem, well-known in the art, that a pallet desired to be moved may be in a location that is unreachable by a fork lift truck, or even a hand jack, because of the lack of a dock or ramp, height or width limitations, or weight restrictions. In this case, it is known to solve the problem with a winch, chain, and pallet pullers. Pallet pullers comprise, in one conventional embodiment, a pair of curved gripping heads on arms connected to each other by a pivot, or in some arrangements, a scissoring arrangement. The ends of the arms, distal to the dripping heads, are connected to each other by a short length chain. A chain attached to the winch of a fork lift is then attached to the connecting chain and the gripping heads are arranged to grasp the stringers of a pallet. As the chain is winched in, the gripping heads bite into the stringers and pull the pallet in the direction that the chain is being pulled. It is a disadvantage with this arrangement that the gripping heads are easily detached during use if the chain is pulled at an angle. Stop-and-go pulling causes disengagement, resulting in loss of time, and consequently, additional expense. This is particularly the case when pulling of pallets is done by a lone operator of a high-low fork lift unit, who must dismount and mount the unit each time disengagement occurs. Moreover, since the jaws bite into the pallet wood to grasp the pallet, these pallet pullers damage the pallet. Thus, there is a need for a pallet puller arrangement that will not significantly damage the pallet during attachment and use. In addition to the foregoing problems, conventional pallet pullers are heavy (up to about 21 lbs., for example) and expensive to purchase. There is, therefore, a need in the art for a pallet puller arrangement that is economical, lightweight and convenient to carry and store.
It is also well known to construct pallet pullers, inexpensively, from a piece of metal bent in an L-shape. Typically, the L-shaped pallet pullers have an elongated arm having a length sufficient to hook around the rear of a lower deck board of the pallet to be moved. These pallet pullers are, of course, bulky and inconvenient to carry and store. Moreover, turning the pallet is not an option. There is, therefore, a need in the art for a pallet puller arrangement that can easily be attached to the pallet. The L-shaped pallet pullers also suffer from the disadvantage that they can easily become detached during use.
It is further a problem with all known pallet pullers that there is a “slingshot effect” if they become disengaged, or damage the pallet to the point of breaking the stringer or deck wood, or breaking through a joint therebetween. The term “slingshot effect” means that the pallet puller and attached chain whip vigorously in the direction that the chain is being pulled. This can damage the materials on the pallet being moved, or surrounding pallets, as well as cause injury to personnel and property. Thus there is a further need in the art for a pallet puller arrangement that will not easily become dislodged during use.
It is, therefore, an object of this invention to provide a pallet puller arrangement that is economical to manufacture, lightweight, and easy to carry and store.
It is another object of this invention to provide a pallet puller arrangement that is easy to attach to the pallet and is retained in position once attached.
It is also an object of this invention to provide a pallet puller arrangement that does not significantly damage the pallets.
It is additionally an object of this invention to provide a pallet puller arrangement that readily enables a loaded pallet to be rotated so as to be reoriented, and pulled.
It is additionally an object of this invention to provide a pallet puller arrangement that resists bending when a heavily loaded pallet is reoriented or pulled at an angle.
SUMMARY OF THE INVENTION
The foregoing and other objects are achieved by this invention which provides a pallet puller arrangement that interlocks around a stringer and the lead deck board of a pallet or skid. The pallet puller arrangement is adapted to be used in conjunction with a chain and winch mechanism in order to move a pallet in a desired direction. In an apparatus embodiment, the pallet puller arrangement comprises a unitary body having an elongated principal body portion with an aperture at one end thereof. The aperture is suitable for engaging with a chain quick link or any other suitable engagement means to link a chain to the pallet puller arrangement. Distal to the apertured end, the pallet puller arrangement has an engagement portion for coupling around a stringer of a pallet so as to abut a lead, load-bearing cross-member, or deck board, of the pallet.
In a highly advantageous embodiment of the invention, the engagement portion comprises a stringer cradling portion that is generally perpendicular to the elongated body portion and which is provided a flange extending upwardly from the stringer cradling portion in a direction substantially parallel to the elongated body portion. The upwardly extending flange has a protuberance extending beyond a front face of the laterally extending support surface of the stringer cradling portion in a direction toward the aperture. The protuberance, which has a flat bottom portion that is coplanar with the upper surface of the laterally extending support surface of the stringer cradling portion, is adapted to overlie an interior surface of a deck board. The laterally extending support surface is adapted to accommodate the width of the stringer board.
In operation, the pallet stringer is cradled on one side by the elongated body portion over edge thereof by the laterally extending support surface of the stringer cradling portion and on the other side by the flange. Simultaneously, the protuberance is urged by the user to overlie an interior surface of a deck board, thereby securely hooking the pallet puller arrangement to the pallet. As a result of the hooking mechanism, the arrangement of the present invention is much less likely to disengage during use than known arrangements. Moreover, the pallet puller arrangement of the present invention is much less likely to cause damage to a pallet during use.
The pallet puller arrangement should be constructed of strong, yet somewhat pliable or flexible metal. Tempered steel, for example, is too brittle and could break during use resulting in a slingshot effect. In a preferred
Cherry Johnny D.
Rohm & Monsanto, P.L.C.
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