Scissors type lifting table for deep drawing plant - has fast operation but low inertial stresses at motion reversing positions

摘要

In a scissors type lifting table for a deep drawing plant with a table platform mobile within two extreme positions a main frame, as well as at least one, pref. double-member, lifting scissors between the main frame and the platform table, the drive of the scissors on its pivot arms takes place via an oscillating crank slot with motor-swung crank. Pref. the scissors drive assembly of motor, transmission gear, crank pivot shaft and crank, is so arranged w.r.t. the scissors and at the same time the effective dia. of the circle of revolution of the crank is selected in such a way that the circle of motion of the effective guide path for the crank slot is tangential to the scissor arms in the two extreme positions of the scissors unit. This meets the requirements for the transport level of the plastic film within the deep drawing plant to be at about the working height for a man when standing, where the use of a trench for the lifting table and its drive is ruled out by the need for universal adjustability, and at the same time ensures a drive system with smooth acceleration and retardation but a rapid overall movement.