GB472210A - Improvements in clutches - Google Patents

Abstract

472,210. Free-wheel clutches. TEBALDI, A. Dec. 7, 1936, No. 33520. Convention date, Dec. 7, 1935. [Class 80 (ii)] In a free-wheel clutch which drives in one direction and permits overrunning in both directions, wedging rollers 23 are disposed between a cylindrical surface 8‹ of a driving drum 8 and the inclined ends 211 of blocks 21, which are slidable radially in guides formed in a loose ring 12, and which are urged towards the surface 8‹ by springs 24. The other ends of the blocks are adapted to coact frictionally with a cylindrical surface 1<1> of a member 1 secured to a driven shaft 2. As shown in Figs. 1 and 2, the outer ends of the blocks engage a split friction ring 22 adapted to be expanded into engagement with the surface 1<1>, while in Figs. 6 and 7, the inner ends of the blocks carry shoes 30 adapted to engage the surface 1<1>. The ring 12 pivotally carries shoes 18<11> which are normally maintained in contact with a fixed drum 6 by springs 19, each shoe having a counterweight 18<1>. The ring 12 may also carry spring-loaded detents 14, Fig. 1, which co-operate with the web of the drum 6 so as to permit the ring 12 to rotate only in one direction. With rotation of the drum 8 in one direction (anticlockwise in Fig. 2), the rollers 23 are inoperative, the blocks 21 being retracted by their springs 24 and the ring 12 being held stationary by the brake shoes 18<11>. With rotation of the drum 8 in the other direction, the rollers 23 are operative, and shaft 2 is driven. The shoes 1811 at first slip on the drum 6, but above a certain speed the counterweights 18<1> act centrifugally to draw the shoes 18<11> out of engagement. As shown in Figs. 6 and 7, the arrangement is duplicated, the outer ends of the two sets of blocks being oppositely inclined. Thus the drum 8 may drive the shaft 2 in either direction and the shaft 2 can overrun in either direction. As shown in Figs. 1 and 2, however, wedging rollers 11 are arranged between a cylindrical surface 8<1> of the drum 8 and cam grooves 29 in a part 1<11> of the member 1, so that the drum 8 mav drive the shaft 2 in either direction, while the latter can overrun only in one direction. This latter arrangement may be used in apparatus where the shaft 2 is connected through a friction clutch to a main non-reversible driving motor and the drum 8 is connected to an auxiliary slow-speed reversible motor. The arrangement shown in Figs. 6 and 7, may be used in similar apparatus where the main motor is reversible.