Kickback control and wear adjustment mechanism for disc brake

Claim 2

A kickback control wear adjustment mechanism for a disc brake comprising: a caliper housing; a piston axially movable in said caliper housing, the caliper housing and piston providing walls forming a primary chamber therebetween whereby upon introduction of hydraulic pressure thereto the piston is displaced from the housing and a braking force is applied against a brake lining; an axially extending bore formed in one of the walls; a valve body slidable in the bore and having an axially extending internal valve chamber therein; means holding said valve body in engagement with the other wall of said primary chamber; and a valve assembly in said valve chamber forming with the valve body and the one wall of the primary chamber an expansible chamber, said valve assembly including first valve means providing one-way fluid communication from the primary chamber to the expansible chamber during each hydraulic brake actuation and second valve means separate and spaced from said first valve means at least temporarily retaining a residual pressure in said expansible chamber to resist return of said piston into the caliper housing upon release of hydraulic pressure from the primary chamber and effective to relieve the residual pressure upon application of excessive kickback force against the piston.

Claim 3

The mechanism of claim 1 further characterized by the valve body being slidably fitted into the bore to allow dissipation of the residual pressure from the expansible chamber at a controlled rate.

Claim 4

The valve assembly of claim 1 further comprising: the valve body having an outward-facing shoulder therein providing a valve seat, a port through said valve body proviDing fluid communication between said primary chamber and said internal valve chamber; an annular member having an axially extending bore therethrough stepped down at successive stages to form a plurality of inner-facing shoulders and an outer surface stepped down to form an outward-facing shoulder; a valve seat on the innermost of the inward-facing shoulders; a first spring seat mounted on the intermediate inward-facing shoulder; a ball; a first spring means engaging said first spring seat and biasing said ball against the outermost inward-facing shoulder of said valve body to form said first valve means, said first spring means being overcome upon brake application by the pressure differential between said primary chamber and said expansible chamber, allowing fluid flow around said ball into said expansible chamber; and a second spring means acting against the outward-facing shoulder of said annular member to bias said valve seal against the valve seat of said valve body to form said second valve means, said second spring means being overcome upon brake release or vehicle cornering by pressure differential between said expansible chamber and said primary chamber to control fluid communication from the expansible chamber and thereby control the retraction of said piston into said caliper housing.

Claim 5

The mechanism of claim 3 further characterized by; the axially extending bore being formed in the piston, spring means acting between the piston and the valve body to hold the valve body in engagement with the caliper housing, and the second spring means acting between the outward-facing shoulder of the annular member and the valve body to bias the valve seal against the valve seat of the valve body.

Claim 6

The mechanism of claim 3 further characterized by; the axially extending bore being formed in the piston, a bolt extending through the wall of the caliper housing and threadedly attaching the valve body to the caliper housing, and second spring means acting between the bolt and the outward-facing shoulder of the annular member to bias the valve seal against the valve seat of the valve body.

Claim 7

The mechanism of claim 3 further characterized by; the axially extending bore being formed in the caliper housing, spring means acting between the caliper housing and the valve body to hold the valve body in engagement with the piston, and a second spring means acting between the outward-facing shoulder of the annular member and the caliper housing to bias the valve seal against the valve seat of the valve body.