Finished France Theater Stages Construction Projects: worm gear screw jacks lift for elevating theatre orchestras with our complete set screw jack lifting platform which includes 10T, 25T screw jacks, high torque miter gearboxes, 5.5KW & 22KW bevel helical geared motors, couplings, pillow blocks and connecting shafts. Compared with hydraulic lifting platfrom or electric cylinder actuators lifting platfrom, screw jack lifting platform has self-locking feature without brake or locking mechanism, precisely positioning, full synchronization, motor driven, easy installation and operation, maintenance free.