Negative disc brake with a clearance-takeup mechanism

Claim 2

A negative disc brake comprising a cylinder assembly having a thrusting mechanism wherein a thrusting force of an actuating spring is normally transmitted to a thrusting piston through an actuating piston and an adjustment screw which is in screwed engagement with the actuating piston; the thrusting piston normally pushing against a rotor a first friction pad disposed on one side of the rotor; said actuating piston moving against the thrusting force of said actuating spring in the direction of taking off the brake when fluid pressure is applied; and a caliper assembly having a reaction member which pushes against the opposite side of the rotor a second friction pad disposed on the opposite side of the rotor by a reaction force resulting from the thrusting force exerted on the first friction pad to push the first friction pad against said rotor in a brake applying action of said thrusting mechanism, the negative disc brake being characterized in that the internal end of a spiral spring which exerts a turning force on said adjustment screw is drivingly coupled to the adjustment screw while the external end of the spiral spring is coupled to a lid member which is secured to a member secured to the cylinder assembly; that a cup-shaped cover is secured to the lid member; and that a resilient ring which engages with the outer circumference of said cup-shaped cover is secured to the inner circumferential end part of the cylinder assembly, said negative disc brake further comprising a spring on the actuating piston for preventing the head portion of the adjustment screw from coming into direct contact with the actuating piston.

Claim 3

A negative disc brake as defined in claim 1, wherein said spring is a coil spring which securely engages with an inner circumferential groove provided in said actuating piston.

Claim 4

A negative disc brake comprising a cylinder assembly having a thrusting mechanism wherein a thrusting force of an actuating spring is normally transmitted to a thrusting piston through an actuating piston and an adjustment screw which is in screwed engagement with the actuating piston; the thrusting piston normally pushing against a rotor a first friction pad disposed on one side of the rotor; said actuating piston moving against the thrusting force of said actuating spring in the direction of taking off the brake when fluid pressure is applied; and a caliper assembly having a reaction member which pushes against the opposite side of the rotor a second friction pad disposed on the opposite side of the rotor by a reaction force resulting from the thrusting force exerted on the first friction pad to push the first friction pad against said rotor in a brake applying action of said thrusting mechanism, the negative disc brake being characterized in that the internal end of a spiral spring which exerts a turning force on said adjustment screw is drivingly coupled to the adjustment screw while the external end of the spiral spring is coupled to a lid member which is secured to a member secured to the cylinder assembly; that a cup-shaped cover is secured to the lid member; and that a resilient ring which engages with the outer circumference of said cup-shaped cover is secured to the inner circumferential end part of the cylinder assembly, said negative disc brake further comprising a spring on the head portion of the adjustment screw for preventing the actuating piston from coming into direct contact with the head portion of said adjustment screw.

Claim 5

A negative disc brake comprising a cylinder assembly having a thrusting mechanism wherein a thrusting force of an actuating spring is normally transmitted to a thrusting piston through an actuating piston and an adjustment screw which is in screwed engagement with the actuating piston; the thrusting piston normally pushing against a rotor a first friction pad disposed on one side of the rotor; said actuating piston moving against the thrusting force of said actuating spring in the direction of taking off the brake when fluid pressure is applied; and a caliper assembly having a reaction member which pushes against the opposite side of the rotor a second friction pad disposed on the opposite side of the rotor by a reaction force resulting from the thrusting force exerted on the first friction pad to push the first friction pad against said rotor in a brake applying action of said thrusting mechanism, the negative disc brake being characterized in that the internal end of a spiral spring which exerts a turning force on said adjustment screw is drivingly coupled to the adjustment screw while the external end of the spiral spring is coupled to a lid member which is secured to a member secured to the cylinder assembly; that a cup-shaped cover is secured to the lid member; and that a resilient ring which engages with the outer circumference of said cup-shaped cover is secured to the inner circumferential end part of the cylinder assembly, said negative disc brake further comprising a spring on the head portion of the adjustment screw for preventing the actuating piston from coming into direct contact with the head portion of said adjustment screw.