Pallet lifting fork truck
OwnerAnders Franssoninventor
Life of this patent
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Abstract
Springing for support wheels of low lifting trucks arranged below the forks includes a common spring device arranged in the transfer mechanism of the lifting movement to the support wheels. The spring device includes a cylinder, a piston, a spring package of cup springs and an extending push rod that in the cylinder is connected a ring shaped element located between the spring package and the cylinder end through which the push rod extends. The piston is arranged in the other end of the spring package and the cylinder is via a return valve coupled in parallel with the load lifting hydraulic system of the truck so that the pressure in this pretensions the ring shaped element towards the cylinder end proportionally to the load, so that springing does not take place until the dynamics forces overcome the pretension.
Claims11
A pallet lilting fork truck comprising a platform carrying vertically moveable forks, wherein the platform is supported adjacent its rear by supporting rollers or wheels, and the forks are supported adjacent their front ends by a vertically moveable support wheel assembly, which support wheel assembly upon lifting of the forks moves downwards from the fork, said truck further including a spring device for damping rolling shock to the support wheel assembly.
Spring device for a pallet lifting truck, wherein a first end of the spring device is constituted by a hydraulic cylinder having a piston which is connected at one end to a spring element, and at its other end is connected to a fastening bracket, the spring device including means limiting a total length of the element so that oil fed to the hydraulic cylinder pretensions the spring element, whereby the spring device will not spring at static load but only dampen dynamic forces due to unevenness in floor or ground over which the truck may roll.
Dependencies are inferred from the claim text.