GB296791A - - Google Patents

Abstract

296,791. McIntyre, F. Sept. 8, 1927, [Convention date]. Roots' blower type.-Relates to pumps for metering cellulosic solutions to be spun into artificial silk. The casing comprises two end plates 5, 6 and a centre plate of hard steel having circular cavities in which the pumping gear wheels 8, 9 are received. Wear plates 13, 14 of hard steel may be recessed into the inner surfaces of the end plates. The end plates are positioned by dowel pins 46, 47 and are secured by screws 48 The gears 8, 9 are keyed upon spindles 21, 22 which are mounted in the end plates, the latter preferably being bushed with metal impregnated with a large quantity of graphite. Sufficient clearance is left between the spindles and their bearings and between the gears and the casing to permit of a slight but continuous flow for lubricating purposes of the solution being pumped, and the ends of the spindle bearings are formed with scraping edges to prevent solidification there of the exuding solution. Small lateral recesses may be provided in the side plates to prevent trapping of the solution in the tooth spaces, or, as shown in Fig. 6, adjacent tooth spaces are connected by passages 42 in the bases of the teeth. The external driving wheel 27 is secured to an anti-friction sleeve 28 running on a boss 29 and is coupled to the spindle 21 by a bridge-piece 33 and a coupler 30 having tongue-and-slot connections with the bridge-piece and the spindle. The parts exposed to the solution may be made of alloy steels which the solutions do not corrode or they may be plated with chromium.