The present invention relates to a detachable boom for fork trucks that is releasably attached but further that is safely retained thereto without dependence on a safety chain.
Existing boom accessories for fork trucks include a frame adapted to engage the forks of a fork truck, and a boom extending from the frame. When lifted, the forks lift the frame and in turn lift the boom and any object hanging on an end of the boom. Sometimes during use and/or due to an incline of the forks or of the fork truck itself, the forks will be angled slightly downward. In such case, the boom accessory (and any object carried thereon) will tend to slide forward off the end of the forks (tines). As a result, a safety chain is used that is hooked between the accessory frame and the fork truck's carriage to prevent the accessory frame from accidentally sliding forward off the tines. However, safety chains have been known to be accidentally shaken off or disengaged (or are not properly installed), resulting in a risk to the boom accessory and the carried object can (and sometimes will) come off. This results in damage to the object being moved and, in some circumstances, can cause injury. A more positive retention mechanism is desired that is less sensitive to operator error and less sensitive to being shaken loose or accidentally dislodged.
In one aspect of the present invention, a boom accessory for a fork truck including a carriage and lifting forks, comprises a frame having receiver tubes for receiving the forks, a boom attached to the frame and extending forwardly, and a frame-to-carriage anchor assembly on the frame. The frame-to-carriage anchor assembly includes a carriage-attaching subassembly with top and bottom connectors for securely engaging mating structure on the fork truck's carriage, and includes a vertically-slidable anchor between the carriage-attaching subassembly and the frame to restrain the frame horizontally from sliding forwardly off the forks but that permits vertical movement of the frame relative to the carriage-attaching subassembly. By this arrangement, the forks can lift a weight of the frame, boom, and boom-carried load without stressing the anchor assembly, but can prevent the frame from sliding forward off the forks.
These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings.
The present apparatus includes a boom accessory 20 (
The frame 25 (
The frame-to-carriage anchor assembly 28 (
As noted above, the anchor 34 (
By this arrangement, the forks 23 can lift a weight of the boom accessory 20 (including the frame 25, boom 27, and any boom-carried load) without undesirably stressing the anchor assembly 28, but it positively and effectively prevents the boom accessory (including the frame 25 and boom 27) from accidentally sliding forward off the forks 23.
It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.
This application claims benefit under 35 USC §119(e) of provisional application Ser. No. 61/640,124, filed Apr. 30, 2012, entitled FORK TRUCK BOOM APPARATUS the entire contents of which are incorporated herein by reference.
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Number | Date | Country | |
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