GB688628A - Improvements in hoisting machines - Google Patents

Abstract

688,628. Operating or controlling friction wheels; reversing gearing; variable-speed friction gearing. GARNER, W. March 21, 1951 [Dec. 7, 1949], No. 31395/49. Class 80 (ii). [Also in Group XXX] In a friction-driven hoist a rotary friction-driving wheel is displaceable to engage a load wheel and displace it from engagement with a brake. The driven wheel 5, which is a component of the load wheel, is mounted on a shaft 10, the bearing 13 for which at one end has a pin- and - slot connection 14 with the frame 7. In its lowest position the wheel. 5 rests on the brake 6. The bearings 11, 12 for the shafts of the friction-driving wheels 3, 4 also have a pin-and-slot connection with the frame and rest on screws 26B, 27B mounted in pivoted arms 26, 27. The free ends of these arms rest on the end 28A of a lever 28 which is pivoted at 28B and rocked by chains 29, 30. The wheels 3, 4 are driven in opposite directions by a chain 17 which is passed round sprockets on their shafts and a continuously powerrotated sprocket 18. A weighted lever 23 presses on the bearing 13 and increases the pressure of the wheel 5 on the brake. In a modification the driving and load wheels are journaled on bearings which are turnable about axes eccentric to their circular bearing surfaces, means such as a weighted lever being provided to urge the bearing to turn in a particular direction. In a further modification an auxiliary displaceable rotary friction driving wheel is provided which rotates oppositely to, or in the same direction as, the usual driving wheel. In the first case when the auxiliary wheel is engaged, lowering will be by a power drive. In the second case the auxiliary wheel is of different size and hoisting can take place at slow speed. Two auxiliary driving wheels rotating in opposite directions may be provided.