GB378542A - Improvements in brakes - Google Patents

Abstract

378,542. Brakes. BENDIX BRAKE CO., 401, North Bendix Drive, South Bend, Indiana, U.S.A. May 18, 1931, No. 14625. Convention date, May 21, 1930. [Class 103 (i).] A servo-brake of the kind comprising a pair of linked floating shoes adapted to anchor at one end or the other according to the direction of rotation of the drum is applied by a floating lever disposed within the drum and having upstanding cam parts between the ends of the shoes. The shoes are preferably slightly flexible. The shoes 26, 27 connected by the adjusting screw 29 at one end are adapted to anchor at the other end against a pin 16 secured to the locking plate 15. The ends of the shoes are separated to apply the brake by a lever 18 slotted at 23 to receive the anchor 16 and having upturned end pieces 24 disposed between the shoe ends. An operating cable 19 is ,connected to the end 21 of the lever 18. A plate 34 on the anchor. 16 holds the shoes and lever laterally. In addition to the spring 33 connecting the shoes, there is a second spring 35 extending from the anchor 16 to the shoe 26. Thus when the lever 18 is operated with the drum rotating counterclockwise, the shoe 26 does not leave the anchor and with clockwise rotation, the end of the shoe 27 at first moves radially and outwardly until the shoe engages the drum, without however actually leaving the anchor and then returns to its initial position while the end of the shoe 26 leaves the anchor. The objectionable click due to the return of one of the shoe ends to the anchor is thus avoided. The shoes are held in position in relation to the drum by frictional engagement with spaced bearing surfaces formed on the back plate 15 effected by steady rests 28 comprising coil springs seated on the shoe webs with one end extending through the web and the back plate. The shoes are disengaged from the drum after an application by the " kick of the drum due to the distortion of the drum when the shoes are applied. As shown in Fig. 1, the web of the shoes decreases in height from the ends to the centre part to render them slightly flexible and in order that the flexibility may correspond to that of the drum, the height of the web at the centre part is approximately equal to that of the usual flange on the edge of the drum. Inclined parts 43, 44, Fig. 5, are formed on the back plate 15 for the cable 19 and its sheath 45, the sheath being secured by a plate 46.