A lifting jack with a lifting pre-tightening device comprises an upper clamping jack body, a main jack body, a lower clamping jack body and the lifting pre-tightening device which are sequentially connected. The lifting pre-tightening device is composed of upper lifting clamping sheets, a pressing plate and a pre-tightening block. The pre-tightening block is a short cylinder with a boss at the bottom, and n conical holes used for mounting of the upper lifting clamping sheets are formed in the short cylinder. The pressing plate is in the shape of a circular ring, m through holes are formed in the circular ring, and an inner step is arranged in the circular ring. In the work state, the pre-tightening block is fixedly arranged on the upper clamping jack body of the main jack body, and the upper lifting clamping sheets are arranged in the conical holes, corresponding to the steel strands needing to be adjusted, of the pre-tightening block; and the pressing plate is located outside the pre-tightening block, the inner step of the pressing plate is clamped on the boss of the pre-tightening block, and bolts and gaskets penetrate the through holes in the outer surface of the pressing plate, so that the pressing plate, the pre-tightening block and the upper clamping jack body are connected. According to the lifting jack with the lifting pre-tightening device, in the lifting process, the problematic steel strands can be evenly pre-tightened in time, m is an integer from 2 to 20, and n is an integer from 7 to 66.
Lifting jack with lifting pre-tightening device and method for lifting jack for pre-tightening lifting steel strands
2015-12-16
Patent
Electronic Resource
English
IPC: | B66F HOISTING, LIFTING, HAULING, OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD , Hub-, Verhol- oder Schubvorrichtungen, soweit nicht anderweitig vorgesehen, z.B. Vorrichtungen mit unmittelbarer Krafteinwirkung auf die Last |