Brake actuating and adjusting mechanism

Claim 2

A brake actuator and adjuster comprising: a wheel cylinder formed in a housing and having a brake actuating piston reciprocably received therein and cooperating therewith to define a brake actuating pressure chamber; a high-lead screw secured to said piston and extending into said pressure chamber; an adjuster nut and clutch face member threaded on said screw for axial and rotational movement; a mechanical actuator including a shaft extending into said pressure chamber in axial alignment with said piston and said screw and having means for operatively mechanically imparting axial force and movement thereto toward said piston; means limiting axial movement of said nut and clutch face member in one direction relative to said shaft and in the other direction relative to said housing; a clutch member mounted on said piston for axial movement relative thereto and having a clutch face engageable with the clutch face of said nut and clutch face member to prevent rotation of said nut and clutch face member relative to said piston upon sufficient axial movement and force of said shaft toward said piston and to transmit further axial movement and force of said shaft to said piston; and means returning said shaft in an axial direction away from said piston when said mechanical actuator is released; said adjuster nut and clutch face member maintaining adjustment of said piston by requisite rotational and axial movement thereof on said screw when said piston is moved by pressure in said chamber beyond the limit of movement set by said limiting means for said nut and clutch face member.

Claim 3

A brake mechanism comprising: a housing having a brake actuating piston reciprocably received therein and cooperating therewith to define a pressure chamber, said piston having a brake pad assembly on the outer side and a recess defined by a piston skirt on the inner side, the wall of said skirt defining said recess having a plurality of splines extending axially parallel to the axis of piston movement in said housing; a threaded member secured to said piston and extending through said recess coaxially with the axis of piston movement in said housing; an adjusting nut threaded on said threaded member and rotatable relative thereto in screw relation, one side of said nut forming a clutch face surface and the other side of said nut having an axially effective restrainer thereon which permits relative rotation of said nut; a clutch plate splined to said piston skirt splines for axial Movement relative thereto and having a clutch face surface in axially movable engageable relation to said adjusting nut clutch face surface, and having a plurality of slots formed therein in circumferentially spaced relation radially outward of said clutch face surface; an actuating shaft rotatably and reciprocably mounted in said housing with one end extending into said chamber and engaging said clutch plate, the other end extending outward of said housing and having an actuating lever secured thereto to impart rotational movement to the shaft, and a center portion having a flange thereon, the flange having a plurality of axially extending slots in the outer periphery thereof and one side surface formed to receive a plurality of rotatable balls of a ball-ramp actuator; a ball-ramp actuator including a plurality of rotatable balls received on said flange one side surface and ball ramps formed on said housing and a ball cage member circumferentially positioning said balls; and means resiliently urging said shaft axially outward of said chamber away from said piston and yieldably opposing axial movement of said shaft occasioned by rotation of said actuating lever and action of said ball-ramp actuator; said restrainer having a plurality of actuating fingers extending axially away from said piston through said clutch plate slots and said shaft flange slots and formed with inwardly extending lips on the outer ends thereof engaging said flange one side surface to effectively prevent axial movement of said adjuster nut relatively away from said flange beyond a predetermined distance, said finger outer ends being in abuttable relation with said housing to effectively prevent axial movement of said adjuster nut in a direction away from said piston beyond a predetermined position relative to said housing.

Claim 4

A brake mechanism comprising: a housing having a brake actuating piston reciprocably received therein and cooperating therewith to define a pressure chamber, said piston having a brake pad assembly on the outer side and a recess defined by a piston skirt on the inner side, the wall of said skirt defining said recess having a plurality of splines extending axially parallel to the axis of piston movement in said housing; a threaded member secured to said piston and extending through said recess coaxially with the axis of piston movement in said housing; an adjusting nut threaded on said threaded member and rotatable relative thereto in screw relation, one side of said nut forming a clutch face surface and the other side of said nut having an axially effective restrainer thereon which permits relative rotation of said nut; a clutch plate splined to said piston skirt splines for axial Movement relative thereto and having a clutch face surface in axially movable engageable relation to said adjusting nut clutch face surface, and having a plurality of slots formed therein in circumferentially spaced relation radially outward of said clutch face surface; an actuating shaft rotatably and reciprocably mounted in said housing with one end extending into said chamber and engaging said clutch plate, the other end extending outward of said housing and having an actuating lever secured thereto to impart rotational movement to the shaft, and a center portion having a flange thereon, the flange having a plurality of axially extending slots in the outer periphery thereof and one side surface formed to receive a plurality of rotatable balls of a ball-ramp actuator; a ball-ramp actuator including a plurality of rotatable balls received on said flange one side surface and ball ramps formed on said housing and a ball cage member circumferentially positioning said balls; and means resiliently urging said shaft axially outward of said chamber away from said piston and yieldably opposing axial movement of said shaft occasioned by rotation of said actuating lever and action of said ball-ramp actuator; said restrainer having a plurality of actuating fingers extending axially away from said piston through said clutch plate slots and said shaft flange slots and formed with inwardly extending lips on the outer ends thereof engaging said flange one side surface to effectively prevent axial movement of said adjuster nut relatively away from said flange beyond a predetermined distance, said finger outer ends being in abuttable relation with said housing to effectively prevent axial movement of said adjuster nut in a direction away from said piston beyond a predetermined position relative to said housing.