LIFT Russian patent published in 1995 - IPC

FIELD: lifting facilities. SUBSTANCE: lift has load-carryong member, piston drive in form of two tiers of power cylinders uniformly spaced around load-carrying member and hinge-connected with member and guide arrangement made in form of two holders. The latter are installed for longitudinal travel coaxially with load-carrying member. Fitted in holders are toroidal ampoule-like flexible envelopes filled with working medium. Circular step is made on inner part of outer surface of each envelope. This step mates with holder. Outer side of envelope outer surface engages with shaft wall. When pressure is delivered to piston spaces of upper tier power cylinders and rod spaces of lower tier power cylinders, load-carrying member starts moving upwards. Owing to reaction acting through circular step, pressure in upper flexible envelope rises and upper envelope serves as support; other flexible envelope slips along shaft wall. At the end of stroke of power cylinders pressure is changed over, and now lower envelope becomes a support, and upper one slips along shaft wall. EFFECT: enhanced reliability of operation. 2 dwg