Disc brake actuator

Claim 1

In a disc brake assembly of the kind having a clamp housing fixedly mounted to a body which surrounds a rotatable member whose rotational movement is to be restrained in response to operation of said brake assembly, said rotatable member having a substantially planar rotatable disc fixedly joined thereto perpendicularly to the axis of rotation thereof, said disc being arranged to operatively rotate in the vicinity of said clamp, said clamp over-extending a portion of said disc and including at least one brake assembly operative to frictionally engage said disc in response to the application of pressurized fluid thereto, said brake assembly comprising: an elastically deformable, self-supporting spring pipe arranged to be fixedly mounted only at one end thereof to said clamp for linearly expansible movement within an axially extending opening provided in said clamp, said opening in said clamp being disposed so as to enable said spring pipe to expand axially toward said rotatable disc while exposing an axially extending portion of said spring pipe to the exterior of said clamp for enabling outside air to operatively flow past said spring pipe for providing cooling within said clamp by the removal of heat therefrom; a pressure head fixedly joined to and operatively sealing the other end of said spring pipe and slidable in said opening; a frictional coating disposed between said pressure head and said disc brake; and means connected to said one end of said spring pipe for communicating fluid pressure from an outside source to said spring pipe to produce said expansible movement wherein said pressure head forcibly bears against said frictional coating and said disc to retard the movement of said disc in response to said fluid pressure when said brake assembly is operated, and said spring pipe maintains a predetermined clearance between said pressure head and said disc to permit said disc to move freely in the vicinity of said housing when said brake assembly is not operated, whereby friction temperatures normally present within said brake assembly can be decreased.