GB343784A - Improvements in operating means for electric condensers or other instruments - Google Patents

Abstract

343,784. Linkwork. WILKINS & WRIGHT, Ltd. and HEWITT, J. H., Utility Works, Holyhead Road, Handsworth, Birmingham. March 21, 1930, No. 9049. [Class 80 (iii).] Operating g means for elect r i c condensers or other instruments comprises a rotatable driving drum 1, a stationary drum 16, and a driven member 12, a chain or other flexible member 18 passing around the drums 1, 16 and also pulleys 15 or abutments on the driven member 12 and being fastened to the drums 1, 16. The driven member 12 is thereby rotated at half the speed of the driving pulley 1. Secured to the driving drum 1 is a hollow control drum 3 carrying on its periphery a scale 4 and driven by friction gearing from a control knob 25. The member 12 is fastened to a sleeve 6 which is fitted with an insulating bush 23 adapted to receive the shaft of the condenser &c. to be controlled, or the shafts of two ganged condensers. The chain 18 is tensioned by a spring 21 within the fixed drum 16. In order to obtain a greater reduction ratio between the driving and driven members, more than one driving and stationary drums may be arranged so that the driven member of the first unit acts as the driving member of the second unit and so on. The member 12 may carry two idler pulleys 15, and two chains may be employed for driving in opposite directions. The control drum 3 may be operated directly by thumb control, or may be in the form of a dial. The drum 3 may be of transparent or translucent material and illuminated from behind. According to the Provisional Specification a single endless chain &c. may be used, attached to the two drums between the two pulleys, and the chain &c. may be wound completely round the two drums for several turns, so as to permit more than one rotation of the driven member.