Self-energized disc brake parking brake integral with a non-energized service disc brake

Claim 2

A disc brake assembly comprising in combination: a disc to be braked against rotation; a caliper assembly having a first brake pad assembly and a second brake pad assembly mounted thereon and movable to engage said disc in friction braking relation, one of said brake pad assemblies having a peripheral section and a central section mounted in and guided by and transmitting braking force to said peripheral section and including means for transmitting actuating forces from said peripheral section to said center section; first brake actuating means for actuating said one brake pad assembly peripheral section and thereby actuating said one brake pad central section and by reaction actuating the other of said brake pad assemblies; and second brake actuating means actuable independently of said first brake actuating means for actuating said one brake pad assembly central section and by reaction actuating the other of said brake pad assemblies and including self-energizing means for generating a self-energizing force that is effective only upon actuation of said second brake actuating means.

Claim 3

A disc brake comprising: a disc to be braked against rotation; a caliper assembly including: a caliper housing slidably mounted relative to said disc and having legs disposed on opposite sides of said disc and a bridging section joining said legs, a cylinder formed in one of said caliper legs and having a brake actuating piston reciprocably received therein, a first brake pad assembly mounted on said caliper housing axially intermediate the other of said caliper legs and said disc for friction braking engagement with said disc, a second brake pad assembly mounted on said caliper housing axially intermediate said one caliper leg and said disc for friction braking engagement with said disc, said second brake pad assembly including a peripheral shoe having a non-circular opening therein and a peripheral lining secured thereto, a non-circular central shoe received in said non-circular opening and having a central lining secured thereto, said central and peripheral shoes having overlapping lipped shoulders at the circumferentially spaced ends of said central shoe and providing spaced abutments for transmission of braking force from said central shoe to said peripheral shoe upon relative movement thereof in a circumferential direction to abut the cooperating pairs of said shoulders said peripheral lipped shoulders overlapping said central shoe lipped shoulders axially on the side thereof away from said disc, said peripheral shoe being engaged by said piston for braking actuation of said peripheral and central shoes and linings; and a manual brake actuator received in said caliper housing and including a threaded rotatable shaft having an adjuster nut thereon, a clutch formed by a clutch cone and a face on said adjuster nut, a ball and ramp assembly having One ramp means formed in said clutch cone and the other ramp means formed in said central shoe, and means urging said clutch into engagement; actuation of said manual brake actuator by rotation of said shaft acting through said nut and cone and ball and ramp assembly moving said central shoe axially to engage the lining thereof with said disc, the rotational movement of said disc moving said central shoe in a circumferential direction to energize said ball and ramp assembly to self-energize said brake, and reaction force being exerted from said shaft to said caliper housing to cause said first brake pad assembly to engage said disc in braking relation.

Claim 4

A disc brake comprising: a disc to be braked against rotation; a caliper assembly including: a caliper housing slidably mounted relative to said disc and having legs disposed on opposite sides of said disc and a bridging section joining said legs, a cylinder formed in one of said caliper legs and having a brake actuating piston reciprocably received therein, a first brake pad assembly mounted on said caliper housing axially intermediate the other of said caliper legs and said disc for friction braking engagement with said disc, a second brake pad assembly mounted on said caliper housing axially intermediate said one caliper leg and said disc for friction braking engagement with said disc, said second brake pad assembly including a peripheral shoe having a non-circular opening therein and a peripheral lining secured thereto, a non-circular central shoe received in said non-circular opening and having a central lining secured thereto, said central and peripheral shoes having overlapping lipped shoulders at the circumferentially spaced ends of said central shoe and providing spaced abutments for transmission of braking force from said central shoe to said peripheral shoe upon relative movement thereof in a circumferential direction to abut the cooperating pairs of said shoulders said peripheral lipped shoulders overlapping said central shoe lipped shoulders axially on the side thereof away from said disc, said peripheral shoe being engaged by said piston for braking actuation of said peripheral and central shoes and linings; and a manual brake actuator received in said caliper housing and including a threaded rotatable shaft having an adjuster nut thereon, a clutch formed by a clutch cone and a face on said adjuster nut, a ball and ramp assembly having One ramp means formed in said clutch cone and the other ramp means formed in said central shoe, and means urging said clutch into engagement; actuation of said manual brake actuator by rotation of said shaft acting through said nut and cone and ball and ramp assembly moving said central shoe axially to engage the lining thereof with said disc, the rotational movement of said disc moving said central shoe in a circumferential direction to energize said ball and ramp assembly to self-energize said brake, and reaction force being exerted from said shaft to said caliper housing to cause said first brake pad assembly to engage said disc in braking relation.

Claim 5

A disc brake actuator comprising: a caliper housing having a cylinder formed therein; an annular sleeve secured in said cylinder to define therewith an annular pressure chamber for hydraulic brake actuation; an annular piston reciprocably received in said cylinder and having one end forming one wall of said annular pressure chamber and the other end engaging a disc brake pad assembly peripheral section and having an inwardly extending shoulder thereon axially intermediate said piston ends and facing toward said disc brake pad assembly peripheral section; a mechanical brake actuating mechanism including a rotatable input shaft rotatably mounted in said housing in thrust bearing relation thereto and extending through said sleeve and having threads on the inner end thereof, a threaded adjuster nut mounted on said threaded shaft inner end within said annular piston and said annular sleeve and having a clutch surface formed on one end thereof axially inward of said annular sleeve, an adjuster cone received within said annular piston axially adjacent said piston other end and having a clutch surface formed on an inner surface thereof and cooperating with said adjuster nut clutch surface to provide a clutch, a spring retainer mounted on said cone and a compression spring acting on said retainer and said adjuster nut to urge said clutch into engagement, a self-energizing ball and ramp unit having a set of balls and opposed sets of ramps receiving said balls, one set of ramps formed in the end of said cone opposite said adjuster nut and the other set of ramps formed on a disc brake pad assembly central section mounted in said disc brake pad assembly peripheral section for limited movement relative to said disc brake pad assembly peripheral section and for brake torque force transmission thereto; said cone having another end facing said annular piston shoulder and with the actuator released spaced therefrom by a distance substantially equal to caliper housing deflection with the actuator hydraulically actuated; and the limited movement permitted in a disc circumferential direction between said disc brake pad assembly sections being less than the movement required to stop said disc brake pad assembly central section ramp set against said balls when the actuator is hydraulically actuated.

Claim 6

A disc brake actuator comprising: a caliper housing having a cylinder formed therein; an annular sleeve secured in said cylinder to define therewith an annular pressure chamber for hydraulic brake actuation; an annular piston reciprocably received in said cylinder and having one end forming one wall of said annular pressure chamber and the other end engaging a disc brake pad assembly peripheral section and having an inwardly extending shoulder thereon axially intermediate said piston ends and facing toward said disc brake pad assembly peripheral section; a mechanical brake actuating mechanism including a rotatable input shaft rotatably mounted in said housing in thrust bearing relation thereto and extending through said sleeve and having threads on the inner end thereof, a threaded adjuster nut mounted on said threaded shaft inner end within said annular piston and said annular sleeve and having a clutch surface formed on one end thereof axially inward of said annular sleeve, an adjuster cone received within said annular piston axially adjacent said piston other end and having a clutch surface formed on an inner surface thereof and cooperating with said adjuster nut clutch surface to provide a clutch, a spring retainer mounted on said cone and a compression spring acting on said retainer and said adjuster nut to urge said clutch into engagement, a self-energizing ball and ramp unit having a set of balls and opposed sets of ramps receiving said balls, one set of ramps formed in the end of said cone opposite said adjuster nut and the other set of ramps formed on a disc brake pad assembly central section mounted in said disc brake pad assembly peripheral section for limited movement relative to said disc brake pad assembly peripheral section and for brake torque force transmission thereto; said cone having another end facing said annular piston shoulder and with the actuator released spaced therefrom by a distance substantially equal to caliper housing deflection with the actuator hydraulically actuated; and the limited movement permitted in a disc circumferential direction between said disc brake pad assembly sections being less than the movement required to stop said disc brake pad assembly central section ramp set against said balls when the actuator is hydraulically actuated.

Claim 7

In a disc brake having a caliper housing and a hydraulic brake actuator and a mechanical brake actuator, a disc brake pad assembly comprising: a first peripheral shoe section movable in a brake apply direction by one of said brake actuators and formed with an opening therethrough defined by edges including two edges spaced circumferentially relative to the disc to be braked and formed with shoulders and lips extending over said shoulders providing brake force receiving surfaces, and brake lining secured to said shoe section on the side thereof adjacent said shoulders and opposite said lips; a second central shoe section movable in a brake apply direction by the other of said actuators and mating with and received in said first shoe section opening and having two edges spaced circumferentially relative to the disc to be braked and formed with shoulders and lips extending over said shoulders providing brake force transmitting surfaces, and brake lining secured to said second shoe section on the Side thereof adjacent said lips and opposite said shoulders; the shoulders and lips of said first and second shoe section overlapping while permitting limited movement of said second shoe section relative to said first shoe section in circumferential directions relative to the disc to be braked, the shoulders of said first shoe section and the lips of said second shoe section and the lips of said first shoe section and the shoulders of said second shoe section being aligned so as to transmit and receive therebetween brake force from said second shoe section to said first shoe section upon movement of said second shoe section to engage an edge thereof with an edge of said first shoe section in brake force transmitting relation, said lips of said shoe sections also transmitting brake apply force from said first shoe section to said second shoe section when said first shoe section is moved in the brake apply direction by one of the brake actuators.

Claim 8

In a disc brake having a caliper housing and a hydraulic brake actuator and a mechanical brake actuator, a disc brake pad assembly comprising: a first peripheral shoe section movable in a brake apply direction by one of said brake actuators and formed with an opening therethrough defined by edges including two edges spaced circumferentially relative to the disc to be braked and formed with shoulders and lips extending over said shoulders providing brake force receiving surfaces, and brake lining secured to said shoe section on the side thereof adjacent said shoulders and opposite said lips; a second central shoe section movable in a brake apply direction by the other of said actuators and mating with and received in said first shoe section opening and having two edges spaced circumferentially relative to the disc to be braked and formed with shoulders and lips extending over said shoulders providing brake force transmitting surfaces, and brake lining secured to said second shoe section on the Side thereof adjacent said lips and opposite said shoulders; the shoulders and lips of said first and second shoe section overlapping while permitting limited movement of said second shoe section relative to said first shoe section in circumferential directions relative to the disc to be braked, the shoulders of said first shoe section and the lips of said second shoe section and the lips of said first shoe section and the shoulders of said second shoe section being aligned so as to transmit and receive therebetween brake force from said second shoe section to said first shoe section upon movement of said second shoe section to engage an edge thereof with an edge of said first shoe section in brake force transmitting relation, said lips of said shoe sections also transmitting brake apply force from said first shoe section to said second shoe section when said first shoe section is moved in the brake apply direction by one of the brake actuators.