GB478393A - Improvements in or relating to brakes - Google Patents

Abstract

478,393. Internal-expanding brakes. SOC. ANON. FRANCAISE DU FERODO. Dec. 29, 1936, No. 35649. Convention date, Feb. 8. [Class 103 (i)] In an internal-expanding brake, the shoes a, a<1>, are mounted on a fixed pin c at their lower ends and are expanded by a pair of levers d, d<1>, turning on fixed pins e, e<1>, and each having a notched end 21, 21a engaging the notched upper end of the corresponding shoe. The levers are operated by a Bowden cable of which the cable proper i is connected at j to lever d and the sheath k abuts on lever d<1>. The arms of the levers may be such that less pressure is applied by the lever to the shoe a the pressure on which is increased by the rotation of the drum than to the shoe a<1>. The levers are pivoted between members 12 secured to the back plate f. The release springs b, b<1> pass around pins 10, 14 so that they are oblique to the plane of the back plate and thus serve also to hold the shoes laterally against seats 22 on the back plate to prevent rattle. A further release spring m is attached to the end of lever d<1> and to the pin e. To perniit of adjustment of the shoes for wear, the pin c has a conical end 8 upon which the shoe ends bear and screws into a plate 3 secured to the back plate f, the pin being turned by a stud 7 and having a lock nut 4. The screws 2 by which the plate 3 is secured to the plate f pass through elongated holes in that plate to permit of adjustment of the pin for centring the shoes. A ring 6 disposed between the ends of the shoes and the plate 3 is adapted by its expansion in length with increase of temperature to move the shoe ends along the conical end 8 of the pin as the drum heats up and thus ensure a compensation as regards the pressure of the shoes against the drum.