Disc brake caliper with integral parking brake

Claim 2

A disc brake caliper assembly for braking a rotating disc and comprising: a caliper housing; first and second brake shoe assemblies located respectively on opposite sides of the disc, the first brake shoe assembly engaging the caliper housing; a first piston sealingly slidable in the housing and engaging the second brake shoe assembly; means preventing rotation of the first piston in the housing; a second piston sealingly slidable in the first piston and cooperating with the first piston and the housing to define a chamber; cone clutch means acting between the first and second pistons, the cone clutch means being normally engaged to prevent rotary movement of the second piston and being disengageable upon axial movement of the second piston relative to the first piston in the direction axially away from the disc; means providing an axial force transmitting connection between the first and second pistons when the cone clutch means is engaged; an adjuster nut normally in axial force transmitting engagement with the second piston; spline means connecting the adjuster nut and the second piston preventing relative rotary movement therebetween and permitting axial movement of the second piston out of engagement with the adjuster nut; means associated with the housing threadedly engaging the adjuster nut and imparting axial movement to the adjuster nut and the second piston upon rotary movement of the associated means; means for introducing fluid pressure to the chamber to displace the first and second pistons unitarily toward the disc; spring means acting on the second piston to move the second piston relative to the first piston in the direction axially away from the disc and thereby disengage the cone clutch means; and second spring means acting to impart rotary and axial movement of the adjuster nut and second piston toward the disc when the cone clutch means is disengaged thereby effecting reengagement of the cone clutch means and holding the first piston in closer wear adjusting relationship with the disc.

Claim 3

A disc brake caliper assembly for braking a rotating disc and comprising: a caliper housing; first and second brake shoe assemblies located respectively on opposite sides of the disc, the first brake shoe assembly engaging the caliper housing; a first hollow piston sealingly slidable in the housing and engaging the second brake shoe assembly; means preventing rotation of the first piston in the housing; means forming a frusto-conical surface on the inner periphery of the first piston; a second piston sealingly slidable in the first piston and cooperating with the first piston and the housing to define a chamber; means forming a frusto-conical surface on the outer periphery of the second piston, the second piston having a normal axial position relative the first piston wherein the respective frusto-conical surfaces are engaged to prevent rotary motion of the second piston and provide an axial force transmitting connection between the first and second pistons, the second piston being movable relative to the first in the direction away from the disc to disengage the frusto-conical surfaces; an adjuster nut normally in axial force transmitting engagement with the second piston; spline means connecting the adjuster nut and the second piston preventing relative rotary movement therebetween and permitting axial movement of the second piston out of engagement with the adjuster nut; means associated with the housing threadedly engaging the adjuster nut and imparting axial movement to the adjuster nut and the abutting second piston upon rotary movement of the associated means whereby the first piston is moved axially in the housing to effect mechanical actuation and release of the brake; means for introducing fluid pressure to the chamber to generate a force on the first and second pistons to effect Forced engagement of the brake pad assemblies with the disc and maintain engagement of the frusto-conical surfaces; spring means acting on the second piston to move the second piston relative to the first piston in the direction disengaging the respective frusto-conical surfaces; and second spring means effecting rotary and axial movement of the adjuster nut and second piston toward the disc only when the frusto-conical surfaces are disengaged thereby effecting re-engagement of the frusto-conical surfaces and holding the first piston in closer wear adjusting relationship with the disc.

Claim 4

A disc brake caliper assembly for braking a rotating disc and comprising: a caliper housing; first and second brake shoe assemblies located respectively on opposite sides of the disc, the first brake shoe assembly engaging the caliper housing; a first hollow piston sealingly slidable in the housing and engaging the second brake shoe assembly; means preventing rotation of the first piston in the housing; means forming a frusto-conical surface on the inner periphery of the first piston; a second piston sealingly slidable in the first piston and cooperating with the first piston and the housing to define a chamber; means forming a frusto-conical surface on the outer periphery of the second piston, the second piston having a normal axial position relative the first piston wherein the respective frusto-conical surfaces are engaged to prevent rotary motion of the second piston and provide an axial force transmitting connection between the first and second pistons, the second piston being movable relative to the first in the direction away from the disc to disengage the frusto-conical surfaces; an adjuster nut normally in axial force transmitting engagement with the second piston; spline means connecting the adjuster nut and the second piston preventing relative rotary movement therebetween and permitting axial movement of the second piston out of engagement with the adjuster nut; means associated with the housing threadedly engaging the adjuster nut and imparting axial movement to the adjuster nut and the abutting second piston upon rotary movement of the associated means whereby the first piston is moved axially in the housing to effect mechanical actuation and release of the brake; means for introducing fluid pressure to the chamber to generate a force on the first and second pistons to effect Forced engagement of the brake pad assemblies with the disc and maintain engagement of the frusto-conical surfaces; spring means acting on the second piston to move the second piston relative to the first piston in the direction disengaging the respective frusto-conical surfaces; and second spring means effecting rotary and axial movement of the adjuster nut and second piston toward the disc only when the frusto-conical surfaces are disengaged thereby effecting re-engagement of the frusto-conical surfaces and holding the first piston in closer wear adjusting relationship with the disc.

Claim 5

A disc brake caliper assembly for braking a rotating disc and comprising: a caliper housing; first and second brake shoe assemblies located respectively on opposite sides of the disc, the first brake shoe assembly engaging the caliper housing; a first hollow piston sealingly slidable in the housing and associated with the second brake shoe assembly in a manner preventing rotation of the first piston in the housing; a clutch element attached to the inner periphery of the first piston, the inner periphery of the clutch element forming a frusto-conical surface; a second hollow piston sealingly slidable in the first piston and cooperating with the first piston and the housing to define a chamber, the outer periphery of the second piston forming a frusto-conical surface, the second piston having a normal axial position relative the first piston wherein the respective frusto-conical surfaces are engaged to prevent rotary movement of the second piston and provide an axial force transmitting connection between the first and second pistons, the second piston being movable relative the first in the direction axially away from the disc to disengage the frusto-conical surfaces; an adjuster nut normally in axial force transmitting engagement with the second piston; spline means connecting the adjuster nut and the second piston and preventing relative rotary movement therebetween and permitting axial movement of the second piston out of engagement with the adjuster nut; screw means rotatably received through the caliper housing and threadedly engaging the adjuster nut, the screw means including axial thrust receiving means engaging the caliper housing; means adapted to rotate the screw means whereby axial movement is imparted to the adjuster nut and the abutting second piston to move the first piston axially in the housing to effect actuation and release of the brake; means for introducing fluid pressure to the chamber to generate a force on the first and second pistons moving the second piston out of engagement with the second piston, effecting forced engagement of the brake pad assemblies with the disc, and maintaining engagement of the frusto-conical surfaces; spring means acting on the second piston and effective upon release of fluid pressure to move the second piston relative the first piston thereby effecting disengagement of the frusto-conical surfaces and re-engagement of the second piston with adjuster nut; and second spring means acting to impart rotary and axial movement to the adjuster nut and the second piston toward the disc when the frusto-conical surfaces are disengaged thereby effecting re-engagement of the frusto-conical surfaces and holding the first piston in closer wear adjusting relationship with the disc.

Claim 6

A disc brake caliper assembly for braking a rotating disc and comprising: a caliper housing; first and second brake shoe assemblies located respectively on opposite sides of the disc, the first brake shoe assembly engaging the caliper housing; a first hollow piston sealingly slidable in the housing and associated with the second brake shoe assembly in a manner preventing rotation of the first piston in the housing; a clutch element attached to the inner periphery of the first piston, the inner periphery of the clutch element forming a frusto-conical surface; a second hollow piston sealingly slidable in the first piston and cooperating with the first piston and the housing to define a chamber, the outer periphery of the second piston forming a frusto-conical surface, the second piston having a normal axial position relative the first piston wherein the respective frusto-conical surfaces are engaged to prevent rotary movement of the second piston and provide an axial force transmitting connection between the first and second pistons, the second piston being movable relative the first in the direction axially away from the disc to disengage the frusto-conical surfaces; an adjuster nut normally in axial force transmitting engagement with the second piston; spline means connecting the adjuster nut and the second piston and preventing relative rotary movement therebetween and permitting axial movement of the second piston out of engagement with the adjuster nut; screw means rotatably received through the caliper housing and threadedly engaging the adjuster nut, the screw means including axial thrust receiving means engaging the caliper housing; means adapted to rotate the screw means whereby axial movement is imparted to the adjuster nut and the abutting second piston to move the first piston axially in the housing to effect actuation and release of the brake; means for introducing fluid pressure to the chamber to generate a force on the first and second pistons moving the second piston out of engagement with the second piston, effecting forced engagement of the brake pad assemblies with the disc, and maintaining engagement of the frusto-conical surfaces; spring means acting on the second piston and effective upon release of fluid pressure to move the second piston relative the first piston thereby effecting disengagement of the frusto-conical surfaces and re-engagement of the second piston with adjuster nut; and second spring means acting to impart rotary and axial movement to the adjuster nut and the second piston toward the disc when the frusto-conical surfaces are disengaged thereby effecting re-engagement of the frusto-conical surfaces and holding the first piston in closer wear adjusting relationship with the disc.