Retractors, Booms and Truck Mounted Cranes

Abstract

The invention relates to the technical field of hoisting, in particular to a hook withdrawal device, a boom and a lorry-mounted crane. The hook withdrawal device comprises a fixed frame, a push rod, a reset elastic element, an arc swinging frame and a swinging structure, wherein the arc swinging frame and the fixed frame are connected rotationally; the push rod and the fixed frame are in sliding connection; the reset elastic element is arranged on the push rod and used for applying force on the push rod, and the force faces an oil cylinder bracket in the boom; and the push rod and the arc swinging frame are connected through a swinging structure. According to the hook withdrawal device provided by the invention, before the boom retracts completely, the arc swinging frame is located at a high position, a lifting hook abuts against a boom head after ascending to a certain height, and accordingly the hook can not be withdrawn; and when the boom retracts completely, the arc swinging frame is located at a low position, and the hook can be withdrawn, that is, the hook withdrawal device cannot withdraw the hook before the boom retracts completely, and therefore the risk that a lifting hook is withdrawn while lifting heavy objects is avoided, and potential safety hazards are eliminated.

Description

Technical field [0001] The invention relates to the technical field of lifting, in particular to a retracting hook device, a boom and a truck-mounted crane. Background technique [0002] When the truck-mounted crane is in a non-working state, it is usually necessary to manually fix the hook to prevent the hook from swinging randomly during transportation, causing damage to the hoisting wire rope, or even crashing the cargo in the container due to the hook swinging with the truck. At present, the first method usually used is to use wood to clamp between the hook and the arm head. After tightening the hoisting wire rope, the wood is clamped by the hook and the arm head to restrict the hook from swinging at will. The second method is to put the hook on the chassis cargo box, and then use other auxiliary materials to fix the hook. In Japan, Furukawa and Tadano have successively developed automatic hooking mechanisms. [0003] The automatic hook-retracting mechanism in the prior art i...

AI Technical Summary

Problems solved by technology

[0005] The object of the present invention is to provide a hook retracting device, a boom and a crane to solve the technical problem in the prior art that there is a safety hazard in retracting the hook when the boom is not fully retracted

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