Compound Screw Jack
Consisting of a jack screw of 4 T. P. I. and double stsrt, carrying a load turn-table. The nut of the screw is fitted on a pedestal bearing and keyed to a worm gear of 40 teeth and mesh with a worm screw. The spindle of the worm screw is provided with an effort wheel of 15 cm diameter.. Weights are not included.