GB191226376A - Improvements in or relating to Power Driven Capstans. - Google Patents

Abstract

26,376. Variable Speed Gear, Ltd., and Robson, J. Nov. 16. Capstans.-A capstan is actuated by a motor which is worked by a pump supplying liquid to the motor at varying rates of flow. The pump and motor are preferably constituted by the pump and motor units of a variable transmission gear. This may be of the kind having a cylinder barrel provided with parallel cylinders for the reception of pistons provided with piston-rods pivotally connected to the pistons and to a plate carried by a tilting box, which, in the case of a pump unit, is displaceable to vary the direction and flow of the liquid. As shown in Fig. 1, a prime mover C<1> drives the pump C of the hydraulic transmission gear, the motor B of which drives the capstan shaft through worm gear. The tilting box is controlled by hand from C<2>. In a modification, the motor shaft carries two spur-wheels driving two spur-wheels on the worm shaft, a clutch being provided to clutch either of the latter wheels to the worm shaft. In another modification, shown in Fig. 4, two or more capstan heads are driven from the same prime mover C<1>. The single pump unit C is in this case in communication with each of the motor units B, suitable valves C<X> distributing pressure liquid to the motor units as required. Instead of this arrangement, each motor unit may have a pump unit, the pump units being driven by a single prime mover. Dangerous pressure in the system may be avoided by providing a relief valve in the valve plate of the pump unit.