Disc brakes and mounting structure therefor

Abstract

The invention concerns disc brakes of the kind in which only one of the friction elements is directly moved into engagement with the brake disc or other rotor, the other friction element being displaced as a result of reaction forces set up by such engagement and for this purpose being carried by a caliper member which is slidable responsive to such reaction forces. In a disc brake of this type in accordance with the present invention, the caliper is mounted for sliding movement on a first pin arranged between the caliper member and a fixed torque plate member adjoining the brake disc, rotation of the caliper member about said first pin being restrained by a second pin secured to one of said members in circumferentially spaced relation with said first pin. The second pin is located in an aperture in the other of said members by an annular eccentric bush which at least partially embraces the second pin and is slidably received in said aperture to enable tolerance in the circumferential spacing of the pins to be accommodated during assembly of the brake and to enable the drag force to be aportioned between the two pins.

I claim: 
     
       1. In a disc brake of the type in which only one of a pair of friction elements is directly moved into engagement with the brake disc; the other friction element being displaced as the result of reaction forces set up by such engagement and for this purpose being carried by a caliper member, in combination with said caliper member, a first pin arranged between the caliper member and a fixed torque plate member adjacent the brake disc and slidably mounting said caliper member, a second pin secured to one of said members in circumferentially spaced relation with said first pin for restraining rotation of the caliper member about said first pin, means defining an aperture in the other of said members, and an annular eccentric bush slidably received in said aperture and at least partially embracing said second pin. 
     
     
       2. A disc brake according to claim 1, in which said second pin is of circular cross-section, and said annular eccentric bush has an inner diameter substantially that of the outer diameter of said second pin and an outer diameter substantially that of said aperture. 
     
     
       3. A disc brake according to claim 2 in which said aperture is located in the caliper member and the eccentric bush is freely rotatable within said aperture whereby tolerance in the circumferential spacing of said first and second pins can be accommodated during assembly of the brake by rotation of the eccentric bush within said aperture to shift the axis of the aperture in the eccentric bush which receives said second pin into line with the axis of that pin. 
     
     
       4. A disc brake according to claim 2 in which said aperture is located in the caliper member and the eccentric bush is freely rotatable within said aperture, the spacing of said first and second pins being preselected during assembly of the brake to achieve a particular orientation of the eccentric bush relative to said second pin and said aperture, whereby the trailing pin is made to take off a predetermined proportion of the drag force. 
     
     
       5. A disc brake according to claim 2 in which said first pin comprises a sleeve and a bolt which clamps the sleeve to the torque plate so that the sleeve is under compression. 
     
     
       6. A disc brake according to claim 2 in which said first pin comprises a sleeve and an elongated screw-threaded stud which engages corresponding internal screw threads on said sleeve located at the end of the sleeve remote from said torque plate for clamping said sleeve to said torque plate. 
     
     
       7. A disc brake according to claim 6 in which said stud is initially provided with a head to enable the stud to be screwed into said torque plate in a manner to apply a compressive load to said sleeve, said head being arranged to shear off the stud when a predetermined compressive load has been applied to said sleeve. .Iadd. 8. A sliding caliper disc brake comprising a rotatable disc, a torque plate member for fixing to a vehicle frame or like portion, a caliper member straddling a minor portion of the periphery of the disc for moving friction pad means disposed on opposite sides of the disc into braking engagement with the disc, portions of the torque plate member being arranged to receive directly drag forces experienced by at least one of the pad means, motor means in the caliper member for directly urging one pad means onto one side of the disc to cause the caliper member to slide relative to the torque plate member to apply by reaction the opposite pad means to the other side of the disc, and a connection between the caliper member and the torque plate member comprising a first component having a surface slidably received in an opening in one of said members said surface having a direct, close sliding fit with the portion of said one member defining the wall of said opening, and a second component abutting said first component and in screw threaded engagement with the other of said members to clamp said first component against the other of said members, said first component having an oversized opening therethrough and said second component passing through said oversized opening, the latter being of a size that there is unobstructed spacing between all of that portion of said second component passing through said first component whereby said portion of said second component is at all times out of engagement with said first component and removal of said second component from said first component is thereby facilitated. .Iaddend..Iadd. 9. A sliding caliper disc brake comprising a rotatable disc, a torque plate member adapted for fixing to a vehicle frame or the like, a caliper member slidable relative to said torque plate member for moving friction pad means disposed on opposite sides of said brake disc into braking engagement with said disc, portions of the torque plate member being arranged to receive directly drag forces experienced by at least one of the pad means, at least one pin means constructed in two parts, one of said parts having a sliding surface received in a complementary opening in one of said members said surface having a direct, close sliding engagement with that portion of said one member defining the wall of said opening, the other of said parts passing with clearance fit through an oversize opening in the first part of said pin means, threaded means for connecting said second pin part with the other of said members, said second pin part having an abutment surface engaging said first pin part at one end of said oversized opening and being constructed and arranged that when said second pin part is lockingly connected to said other member by operation of said threaded means the abutment surface on said second pin part clamps the first pin part to said other member and thereby rigidly fixes said first pin part to said other member, said clearance being of a size that there is unobstructed spacing between that portion of said second pin part passing through said first pin part whereby said portion of said second pin part is at all times out of engagement with said first pin part. .Iaddend..Iadd. 10. A sliding caliper disc brake according to claim 9 wherein the one of said members is said caliper member and the other of said members is said torque plate member. .Iaddend..Iadd. 11. A sliding caliper disc brake according to claim 9 wherein said threaded means comprises a threaded portion on said second pin part and a threaded opening in the other of said members engaged by the threaded portion on said second pin part. .Iaddend. .Iadd. 12. A sliding caliper disc brake comprising a rotatable disc, a torque plate member adapted for fixing to a vehicle frame, a caliper member straddling a minor portion of the periphery of the disc and slidable parallel to the axis of said disc for moving friction pad means disposed on opposite sides of the disc into braking engagement with the disc, portions of the torque plate member being arranged to receive directly drag forces experienced by at least one of said pad means, a pin member having a sliding surface received in a complementary opening in one of the two first mentioned members, said surface having a direct, close sliding engagement with that portion of said one member defining the wall of said opening for guiding and supporting said caliper member in its axial movement relative to the torque plate member, and means for rigidly connecting said pin member to the other of said first mentioned members comprising a clearance opening in one of the two last mentioned members, a bolt having a head engaging said one of the last mentioned members at one end of said clearance opening and extending with clearance through said opening into screw threaded engagement with the other of said last mentioned members, an abutment on the other of said last mentioned members engaging said one of the last mentioned members at the opposite end of the clearance opening, said head and said abutment clamping between them said one of the last mentioned members at opposite ends of the clearance opening thereby rigidly fixing said pin to the other of said first mentioned members, said clearance opening being of a size that there is unobstructed spacing between all of that portion of said bolt passing through said clearance opening in said one last mentioned member whereby said portion of said bolt is at all times out of engagement with the one of said last mentioned members. .Iaddend..Iadd. 13. A sliding caliper disc brake according to claim 12 wherein the one of the two first mentioned members is the caliper member, the other of the first mentioned members is the torque plate member, the one of the two last mentioned members is the pin member and the other of the two last mentioned members is the torque plate member. .Iadd. 14. A sliding caliper disc brake comprising a rotatable disc, a torque plate member for fixing to a vehicle frame or like portion, a caliper member straddling a minor portion of the periphery of the disc for moving friction pad means disposed on opposite sides of the disc into braking engagement with the disc, motor means in the caliper member for directly urging one pad means onto one side of the disc to cause the caliper member to slide relative to the torque plate member to apply by reaction the opposite pad means to the other side of the disc, and a connection between the caliper member and the torque plate member comprising a pin element which has a sliding surface in sliding engagement with a wall of an opening in one of said members and which is releasably fixed to the other of said members, and sealing means extending between said pin element and said one of said members and at all times enclosing all of said sliding surface, said sealing means having one end sealed to said one of said members, and having its other end sealed to said pin element so as to protect all of the sliding surface of said pin element even when said caliper member is separated from said torque plate member. .Iaddend..Iadd. 15. The disc brake according to claim 14 wherein said sealing means comprises flexible boot means in sealing engagement with said one member at opposite ends of said opening, and in sealing engagement with said pin element adjacent the ends of said opening. .Iaddend..Iadd. 16. A sliding caliper disc brake comprising a rotatable disc, a torque plate member for fixing to a vehicle frame or like portion, a caliper member straddling a minor portion of the periphery of the disc for moving friction pad means disposed on opposite sides of the disc into braking engagement with the disc, motor means in the caliper member for directly urging one pad means onto one side of the disc to cause the caliper member to slide relative to the torque plate member to apply by reaction the opposite pad means to the other side of the disc, and a connection between the caliper member and the torque plate comprising a two-part pin, one part of said pin having a sliding surface slidable in an opening in one of said members and the other part of said pin fixing said first part with respect to the other of said members, and sealing means extending between said one part and said one of said members and at all times enclosing all of said sliding surface, said sealing means having one end sealed to said one of said members, and having its other end sealed to said one pin part so as to protect all of the sliding surface of said one pin part even when said caliper member is separated from said torque plate member. .Iaddend..Iadd. 17. A sliding caliper disc brake comprising a rotatable disc, a torque plate member for fixing to a vehicle frame or like portion, a caliper member straddling a minor portion of the periphery of the disc for moving friction pad means disposed on opposite sides of the disc into braking engagement with the disc, motor means in the caliper member for directly urging one pad means onto one side of the disc to cause the caliper member to slide relative to the torque plate member to apply by reaction the opposite pad means to the other side of the disc, and a connection between the caliper member and the torque plate member comprising a pin element having a sliding surface in sliding relation with a complementary surface of an opening in one of said members, fastening means securing said pin element with respect to the other of said members, and sealing means extending between said pin element and said one of said members and at all times enclosing all of said sliding surface, said sealing means having one end sealed to said one of said members and having its other end sealed to said pin element so as to protect all of the sliding surface of said pin element even when said caliper member is separated from said torque plate member. .Iadd. 18. A sliding caliper disc brake comprising a rotatable disc, a torque plate member for fixing to a vehicle frame or like portion, a caliper member straddling a minor portion of the periphery of the disc for moving friction pad means disposed on opposite sides of the disc into braking engagement with the disc, motor means in the caliper member for directly urging one pad means onto one side of the disc to cause the caliper member to slide relative to the torque plate member to apply by reaction the opposite pad means to the other side of the disc, and a connection between the caliper member and the torque plate comprising a first component having a sliding surface slidably received in an opening in one of said members, a second component abutting said first component and in releasable engagement with the other of said members to clamp said first component against the other of said members, and sealing means extending between said first component and said one of said members and having releasable engagement with both so as to retain said first component in said opening, said sealing means having one end sealed to said one of said members and having its other end sealed to said first component so as to protect all of the sliding surface of said first component even when said caliper member is separated from said torque plate member. .Iaddend. .Iadd. 19. A sliding caliper disc brake comprising a rotatable disc, a caliper member straddling a minor portion of the periphery of the disc and slidable parallel to the axis of said disc for moving friction pad means disposed on opposite sides of the disc into braking engagement with the disc, a torque plate member adapted for fixing to a vehicle frame, a pin member having a sliding surface received in a complementary opening in one of the two first mentioned members for guiding and supporting said caliper member in its axial movement relative to the torque plate member, and means for rigidly connecting said pin member to the other of said first mentioned members comprising a clearance opening in one of the three members a bolt having a head engaging said one of the three members at one end of said opening and extending with clearance through said opening into screw threaded engagement with one of the two last mentioned members an abutment on said one of the two last mentioned members engaging said one of the three members at the opposite end of the opening, said head and said abutment clamping between them said one of the three members at opposite ends of the opening thereby rigidly fixing said pin to the other of said first mentioned members, said clearance opening being of a size that there is unobstructed spacing between all of that portion of said bolt passing through said clearance opening in the one of said three members whereby said bolt portion is at all times out of engagement with said one member. .Iaddend. .Iadd. 20. A sliding caliper disc brake comprising a rotatable disc, a torque plate member for fixing to a vehicle frame or like portion, a caliper member straddling a minor portion of the periphery of the disc for moving friction pad means disposed on opposite sides of the disc into braking engagement with the disc, motor means in the caliper member for directly urging one pad means onto one side of the disc to cause the caliper member to slide relative to the torque plate member to apply by reaction the opposite pad means to the other side of the disc, and a connection between the caliper member and the torque plate member comprising a pin element which has a sliding surface in sliding engagement with a wall of an opening in one of said members and which is releasably fixed to the other of said members, and sealing means extending between said pin element and said one of said members while having no connection with the other of said members, said sealing means at all times enclosing all of said sliding surface, said sealing means having one end sealed to said one of said members, and having its other end sealed to said pin element so as to protect all of the sliding surface of said pin element even when said caliper member is separated from said torque plate member.