Patent Application
20080175700
This invention relates to a quick release fork attachment for a forklift truck.
Forklift trucks have been used for many years to handle goods in or around warehouses, factories, building sites and the like. These forklift trucks greatly facilitate the manoeuvring of goods. Generally speaking, the forklift trucks are provided with a fork attachment comprising one or a pair of forks which are used to lift and subsequently move the goods. There is, however, a problem with the known types of fork attachments. Typically, the fork attachments have forks that are of a fixed length and are only suitable for manoeuvring certain types of goods. It is not uncommon for the forklift to be used in an environment in which it must manoeuvre goods of varying shapes and sizes and in order to safely manoeuvre the goods, it may be necessary to provide several different fork attachments with forks of different lengths. For example, a forklift used in the construction industry may be required to deliver large wall panels requiring 120″ forks for a large portion of its time and may also be required to deliver lumber for a significant portion of the time which may require standard length, 40″ forks. It is therefore necessary to provide a forklift attachment that will be able to handle both requirements without requiring the decommissioning of the forklift for a significant period of time while a different set of forks are mounted on the forklift truck.
One type of forklift where this becomes particularly significant is the truck mounted forklift, otherwise commonly referred to as a “piggyback” forklift truck. A typical example of such a forklift is that disclosed in GB Patent Specification No. 2,259,292 (Moffett Research & Development Limited). These piggyback forklift trucks are transported on the rear of a carrying vehicle or articulated chassis to the premises of customers where they are used to load or unload goods onto or from the trailer bed. It is often the case that the exact size and shape of the goods to be loaded onto a trailer are not known until the piggyback forklift truck operator arrives at the customers premises and only at that stage may they determine the appropriate sized forks for use in that particular job. If goods of varying sizes requiring different sized forks must be loaded or unloaded, it is desirable to be able to provide the appropriately sized forks with the minimum difficulty and time.
Heretofore, various solutions have been proposed including providing extendable forks such as those disclosed in U.S. Pat. No. 4,498,837 (Kooi et al). However, there are various problems with providing the extendable forks and by and large these are unsuitable for use with particularly heavy goods. Furthermore, generally speaking, the additional reach provided by such extendable forks is relatively limited and in many cases is insufficient. Another solution is to provide separate pairs of forks to suit the particular requirements. One significant disadvantage of this method is that typically considerable time and effort must be spent in removing one set of forks from the fork attachment carriage and substituting a different set of forks in their place, before loading or unloading may commence. This is particularly significant in circumstances where the operator of the forklift truck wishes to move a variety of different size and shaped goods, requiring multiple changes of fork attachments, as is often the case.
This invention relates to a quick release fork attachment for a forklift truck having a fork attachment carriage, the quick release fork attachment comprising:
By having such a quick release fork attachment, it will be possible for an operator of a forklift truck to quickly remove the fork attachment from a carriage and subsequently attach a different fork attachment to the carriage. In this way, it will be possible for the operator of the forklift truck to interchange one or a pair of forks on the forklift truck in a relatively quick and expedient manner that does not require the forklift to be out of commission for a significant period of time.
In one embodiment of the invention, the fork attachment further comprises a carrier bracket, the upright portion of the fork being connected to the carrier bracket and the carrier bracket having the pair of hooks for mounting the fork on the carriage, mounted thereon. It is envisaged that one of the pair of hooks may be located adjacent the upper end of the upright portion and the other of the pair of hooks may be located adjacent the lower end of the upright portion. Preferably, the hook located adjacent the lower end of the upright portion is the pivotably mounted hook. This will facilitate mounting and dismounting of the fork attachment from the fork attachment carriage.
In another embodiment of the invention, the hooks each comprise a jaw portion defining an open mouth for reception of the carriage therein. Preferably, the hooks are arranged with the open mouths of the hooks facing each other. In a further embodiment of the invention, the locking mechanism further comprises a locking pin. It is envisaged that the pivotably mounted hook and the portion of the quick release fork attachment upon which the pivotably mounted hook is mounted each define a through-bore for reception of the locking pin. This is seen as a particularly simple arrangement that will facilitate quick and efficient changing of fork attachments.
The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features and advantages will become apparent from the description, the drawings, and the claims.
The invention will be more clearly understood from the following description of some embodiments thereof, given by way of example only, with reference to the accompanying drawings, in which:
Referring to the drawings and initially to
Referring now to
Referring now to
In order to release the fork attachment 11 and replace the fork attachment with a different fork attachment, for example, one with shorter tines, the above steps are essentially reversed. The operator of the forklift truck 1 brings the mast into either an upright or rearwardly tilted position and releases the locking pin 25 from the through bores 27, 29. The mast is then tilted forwards and the fork attachment carriage 9 is lowered until the fork attachment carriage 9 is free of the hook 21. The forklift truck 1 is then reversed away from the fork attachment 11 and brought into engagement with a different fork attachment in the manner described previously.
Referring to
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It is envisaged that a number of different shapes and sizes of quick release fork attachment may be provided, including a single fork or a pair of forks, as shown. Ideally, forks with tines of varying lengths may be provided. It is envisaged that more than one quick release fork attachment may be provided so that a selection of forks may be used by the operator of the forklift vehicle. Furthermore, it is envisaged that although in the embodiment shown, each of the forks has a carrier bracket mounting the hooks, the hooks could also be mounted directly onto the upright of the forks themselves. Furthermore, in the embodiment shown, a locking pin with a split ring is shown for securing the pivotably mounted hook in a closed position, however, it will be understood that other locking mechanism could also be employed to equal effect. What is important is that the locking mechanism is relatively simple and inexpensive to provide.
In this specification, the terms “comprise, comprises, comprised and comprising” and the terms “include, includes, included and including” are deemed totally interchangeable and should be afforded the widest possible interpretation.
The invention is in no way limited to the embodiment hereinbefore described but may be varied in both construction and detail within the scope of the claims.
