GB360578A - An improved externally contracting brake - Google Patents

Abstract

360,578. Brakes. ROYCE, SIR F. H., Nightingale Road, Derby. Sept. 23, 1930, No. 28456. [Class 103 (i).] Blocks and shoes acting on drums; compensating for wear.-In an external contracting . shoe brake, particularly suitable for epicyclic gears the shoes . are so mounted and connected as to be capable of limited movement in any direction in a plane perpendicular to the axis of the drum and the frictional reaction on the shoes intensifies the application while the load on the two shoes is balanced. The shoes a, a<1> are connected at one end by an adjustable link e. The other end of the shoe a is connected by link d<1> to an operating lever d pivoted to links d<2> carried by a link d<3> from a fixed pivot d<12>. Friction washers d<8> are arranged at the pivots d<4>, d<12>. A pair of links c are pivoted to the end of the shoe a<1>, to the lever d and to a lever b3, the pivot axis d<9> of the links c on the lever d being eccentric to the pivot axis of the lever d in the links d2. The lever b<3> has a fixed pivot b4 and is connected to a lever b which is pivoted to the shoe a and to a fixed point by a link b<1>. The shoes are supported by springs g, g<1>. A pin f<1> on the shoe engages a slot in an arm f<2> frictionally pivoted to a fixed point to effect an automatic adjustment of the shoes. When, to apply the brake, the lower end of the lever d is pulled to the right, it turns on its pivot in the links d<2> and thus first applies the shoe a to the drum, the end a<4> of the shoe a<1> being simultaneously raised by the link c by reason of the eccentricity of the pivot d<9>. The frictional drag of the shoe a is transmitted to the end f<1> of the shoe a<1> bv the link e and to the end a<4> of this shoe by the levers b, b<3>, and link c, thus applying the shoe a<1> to the drum. The drag on the shoe a<1> also tends to apply pressure to the shoe a through the link c and levers b3, b and thus the load on the two shoes is balanced.