GB746285A - Improvements relating to self-priming centrifugal pumps - Google Patents

Abstract

746,285. Friction clutches; friction gearing. SIGMUND PUMPS, Ltd., and SIGMUND, M. July 21, 1954 [July 28, 1953]. No. 20925/53. Classes 80(1) and 80(2). [Also in Group XXVI] A priming pump shaft 12, Fig. 1, is driven from the shaft 5 of a main pump through friction gear wheels 7, 13 and a centrifugal clutch 14. The priming pump casing 9 is mounted on a pair of parallel guide rods 10 (one only shown) for movement relative to a main structure 1. The guide rods 10 are connected by a bridge piece 19, to which are pivoted two .levers 20 having registering recesses which receive a ball 21. Longitudinal movement of . a hand-operated rod 22 causes relative pivotal movement of the two levers 20, whereby the ball 21 emerges from the recesses and causes downward movement of the lower lever 20. This movement is imparted to the casing 9 against the action of springs 18, bringing wheel 13 into frictional engagement with wheel 7. The centrifugal clutch 14 comprises a pair of friction shoes 27, Figs. 2 and 3, each pivotally connected by a bonded rubber bush 29 to a pair of parallel bars 28, which in turn are pivotally connected by a bonded rubber bush 31 to a plate 34 which is bolted to the wheel 13 through spacing posts 35. The bushes 29, 31 are stressed to press the shoes 27 against a drum 26, whereby the drive is transmitted from the wheel 13 to the shaft 12. If the wheels 7, 13 are left in engagement after the shaft has run up to high speed, the action of centrifugal force on weights 30 carried by the bars 28 will pivot the shoes 27 away from the drum 26 to interrupt the drive, thereby preventing overspeeding of the primary pump 8. The Provisional Specification refers to the friction wheels being engaged by an angular movement of the priming pump.