GB815015A - Automatic brakc adjuster - Google Patents

Abstract

815,015. Automatic adjusting mechanism for brakes. BENDIX AVIATION CORPORATION. Dec. 4,1956 [Dec. 9, 1955], No. 37055/56. Class 103 (1). In an automatic adjusting device for brakes in which an adjustably displaceable stop means is located responsibly to displacement of a pressure-responsive movable member in excess of a predetermined amount of lost motion, means are provided which protrude into and are embedded in the surface of the stop means for normally resisting movement thereof and furrowing a path in the surface when such a movement occurs. In the embodiment illustrated in Fig. 1 showing part of an aircraft disc brake, a pressure plate 20 is moved by an annular piston 14 slidably received in a cylinder bore 12 in fixed brake housing 10 and a series of automatic adjusting devices 22 are provided each comprising a pin or stem 24 secured at one end to the pressure plate 20 and having at its other end a nut and washer 32, 34. Surrounding the pin 24 is a sleeve 38 having an open end 40 and housing a helical spring 46. Clearance " D " denotes the clearance which is maintained between the rotatable and non-rotatable parts of the brake. A circular member 48 is fixedly secured to housing 10 and a number of spaced set screws 50 are threadedly received in circular member 48 and are embedded in the surface of sleeve 38. In operation, when piston 14 is moved to right, pressure plate 20 is displaced towards the right until the friction members are fully applied. If wear of the linings has taken place, the distance " D " will have been completely closed and further movement of stem 24 will, acting through shoulder 36 of washer 34, pull the sleeve towards the right against the resistance of set screws 50; the brake applying effort being sufficient to overcome the resistance offered by the set screws 50 which furrow paths 51 (Fig. 3) in the wall of sleeve 38. When the fluid pressure is released, the stem 24 is pushed towards the left by spring 46 through distance " D " until pressure plate re-engages the end 42 of the sleeve. A washer 54, serving as a oneway clutch, is provided to prevent movement of the sleeve when the aircraft wheel is retracted so that the weight of the brake may be carried through the adjuster without interfering with the adjustment mechanism. Fig. 4 illustrates the invention applied to the interior of a fluidpressure piston and cylinder device in which a stem 74 is secured at one end 72 to an end cap 63 screwed into cylinder 55 and set screws 94 are located in a ring 88 carried by the piston 60. The clearance between the shoulder 76 and the end 84 of the sleeve 78 represents the clearance in the brake and the adjusting mechanism operates in a similar manner to that described in the above embodiment.