Disc brake caliper structure

Claim 2

A yoke for use in a disc brake of the type comprising a rotatable disc having first and second opposite faces, first and second friction pad assemblies for engagement respectively with said first and second opposite faces of said disc, a stationary member mounted adjacent to said first face of said disc, a yoke extending over a portion of the periphery of said disc and mounted for sliding movement relative to said stationary member, and an hydraulic actuator adapted to apply said first friction pad assembly directly to said first face of said disc and adapted to apply said second friction pad assembly to said second face of said disc through said yoke, said yoke comprising a one-piece assembly having on one side a substantially planar face adapted to substantially encompass the stationary member and a portion of the periphery of the disc and including a first pair of spaced parallel lugs which both project away from the substantially planar face of the yoke in the same direction and having inner adjacent surfaces defining a pair of spaced flat parallel guiding surfaces of substantial radial depth for direct operative engagement with complementary flat guiding surfaces on opposite sides of the stationary member, said first pair of guiding surfaces on said yoke at least at one pair of corresponding ends leading into opposed bearing surfaces for engagement with complementary shoulders on the stationary member, and a second pair of spaced parallel lugs which project away from the substantially planar face of the yoke in the same direction as said first pair and which are spaced outwardly beyond the outer opposite ends of said lugs of said first pair, opposite ends of said lugs of said second pair being disposed between and located inwardly from spaced parallel planes containing said flat parallel guiding surfaces of said lugs of said first pair, and adjacent inner surfaces of said lugs of said second pair defining abutment surfaces for engagement with the second friction pad assembly and with the hydraulic actuator.

Claim 3

A yoke as claimed in claim 1, wherein said first pair of lugs are located at circumferentially spaced positions on opposite sides of a central recess in said yoke, said central recess being adapted to accommodate the stationary member and the portion of the periphery of the disc, and said second pair of lugs are located at axially opposite ends of said recess.

Claim 4

A yoke as claimed in claim 1, wherein said bearing surfaces are located at the radially outermost ends of said parallel guiding surfaces and extend towards each other.

Claim 5

A yoke as claimed in claim 1, wherein said bearing surfaces are located at the radially innermost ends of said parallel guiding surfaces and extend away from each other in opposite directions.

Claim 6

A yoke as claimed in claim 1, wherein the yoke is constructed from a hollow casting.

Claim 7

A yoke as claimed in claim 1, wherein said bearing surfaces are located at the radially innermost and outermost ends of the parallel guiding surfaces, and each pair of bearing surfaces are adapted to straddle and engage slidably with complementary spaced shoulders on arms on the stationary member.

Claim 8

A disc brake comprising a rotatable disc having first and second opposite faces, first and second friction pad assemblies for engagement respectively with said first and second opposite faces of said disc, a stationary member mounted adjacent to said first face of said disc, a yoke extending over a portion of the periphery of the disc and mounted for sliding movement relative to said stationary member, and an hydraulic actuator adapted to apply said first friction pad assembly directly to said first face of said disc and adapted to apply said second friction pad assembly to said second face of said disc through said yoke, said yoke comprising a one-piece assembly having on one side a substantially planar face substantiAlly encompassing said stationary member and said portion of the periphery of said disc, said yoke including a first pair of spaced parallel lugs which both project away from the substantially planar face of said yoke in the same direction and of which the inner adjacent surfaces comprise a pair of spaced parallel guiding surfaces of substantial radial depth having a direct operative engagement with complementary flat guiding surfaces on opposite sides of said stationary member, and a second pair of spaced parallel lugs at right angles to said first pair and projecting away from the substantially planar face of said yoke in the same direction as said first pair, said lugs of said second pair being spaced outwardly beyond the outer opposite ends of said lugs of said first pair and being disposed between and located inwardly from spaced parallel planes containing said flat parallel guiding surfaces of said lugs of said first pair, and the adjacent inner faces of said lugs of said second pair defining abutment surfaces engaging respectively with said second friction pad assembly and with said hydraulic actuator, and wherein said parallel guiding surfaces at their outermost and uppermost ends lead into opposed bearing surfaces engaging with complementary shoulders on said stationary member, and resilient means acting between said yoke and said stationary member to urge said bearing surfaces into engagement with said shoulders.

Claim 9

A disc brake comprising a rotatable disc having first and second opposite faces, first and second friction pad assemblies for engagement respectively with said first and second opposite faces of said disc, a stationary member mounted adjacent to said first face of said disc, a yoke extending over a portion of the periphery of the disc and mounted for sliding movement relative to said stationary member, and an hydraulic actuator adapted to apply said first friction pad assembly directly to said first face of said disc and adapted to apply said second friction pad assembly to said second face of said disc through said yoke, said yoke comprising a one-piece assembly having on one side a substantially planar face substantiAlly encompassing said stationary member and said portion of the periphery of said disc, said yoke including a first pair of spaced parallel lugs which both project away from the substantially planar face of said yoke in the same direction and of which the inner adjacent surfaces comprise a pair of spaced parallel guiding surfaces of substantial radial depth having a direct operative engagement with complementary flat guiding surfaces on opposite sides of said stationary member, and a second pair of spaced parallel lugs at right angles to said first pair and projecting away from the substantially planar face of said yoke in the same direction as said first pair, said lugs of said second pair being spaced outwardly beyond the outer opposite ends of said lugs of said first pair and being disposed between and located inwardly from spaced parallel planes containing said flat parallel guiding surfaces of said lugs of said first pair, and the adjacent inner faces of said lugs of said second pair defining abutment surfaces engaging respectively with said second friction pad assembly and with said hydraulic actuator, and wherein said parallel guiding surfaces at their outermost and uppermost ends lead into opposed bearing surfaces engaging with complementary shoulders on said stationary member, and resilient means acting between said yoke and said stationary member to urge said bearing surfaces into engagement with said shoulders.

Claim 10

A disc brake as claimed in claim 7, wherein said resilient means comprise a coiled compression spring.

Claim 11

A disc brake as claimed in claim 7, wherein wear resilient devices are interposed between said spaced parallel guiding surfaces on said yoke and said complementary guiding surfaces on said stationary member.

Claim 12

A disc brake as claimed in claim 7, wherein said hydraulic actuator comprises a pair of opposed pistons working in a cylindrical bore in the stationary member and one of the pistons acts directly on one of said second pair of lugs on said yoke to move said yoke in a direction to apply said second friction pad assembly to the disc, the said one piston having a spigot portion located in an opening in the said one of said second pair of lugs, and a resilient annular sleeve being located between the opening and said spigot portion to compensate for tolerance variations between said spigot portion and said opening.

Claim 13

A disc brake as claimed in claim 10 wherein said resilient sleeve is constructed from a synthetic plastics material.

Claim 14

A disc brake as claimed in claim 7, wherein said resilient means comprise a compression spring acting between the outer end of a stud secured in said stationary member and extending radially outwardly through an axially slotted opening in said yoke.

Claim 15

A disc brake as claimed in claim 12, wherein said compression spring acts between spaced retaining plates of which the lowermost plate engages with the base of a recess in said yoke surrounding said opening and the uppermost retaining plate abuts against a spring ring retainer secured to the stud adjacent to its outermost end which projects above said yoke.

Claim 16

A disc brake as claimed in claim 12, where said compression spring acts between the base of a recess surrounding said opening and the head of a stud secured in said stationary member and projecting through said opening with said head located above said yoke.

Claim 17

A disc brake as claimed in claim 7, wherein said resilient means comprise a plate spring acting between said yoke and the head of a stud screwed into said stationary member through an axially extending opening in said yoke.

Claim 18

A disc brake as claimed in claim 15, wherein said hydraulic actuator comprises a pair of opposed pistons working in a cylinder bore in said stationary member and said stud comprises a screw through which at least the pressure space in said cylinder bore between said opposed pistons can be bled.

Claim 19

A disc brake comprising a rotatable disc having first and second opposite faces, first and second fRiction pad assemblies for engagement respectively with said first and second opposite faces of said disc, a stationary member mounted adjacent to said first face of said disc, a yoke extending over a portion of the periphery of said disc and mounted for sliding movement relative to said stationary member, and an hydraulic actuator adapted to apply said first friction pad assembly directly to said first face of said disc and adapted to apply said second friction pad assembly to said second face of said disc through said yoke, said yoke comprising a one-piece assembly having on one side a substantially lunar face substantially encompassing said stationary member and said portion of said periphery of said disc, said yoke including a first pair of spaced parallel lugs which both project away from the substantially planar face of said yoke in the same direction and of which the inner adjacent surfaces comprise a pair of spaced flat parallel guiding surfaces of substantial radial depth having a direct operative engagement with complementary flat guiding surfaces on opposite sides of said stationary member, and a second pair of spaced parallel lugs at right angles to said first pair and projecting away from the substantially planar face of said yoke in the same direction as said first pair, said lugs of said second pair being spaced outwardly beyond the outer opposite ends of said lugs of said first pair and being disposed between and located inwardly from spaced parallel planes containing said flat parallel guiding surfaces of said lugs of said first pair, and the adjacent inner faces of said lugs of said second pair defining abutment surfaces engaging respectively with said second friction pad assembly and which said hydraulic actuator, and wherein bearing surfaces at the radially innermost and outermost ends of said parallel guiding surfaces straddle and engage slidably with complementary spaced shoulders on arms on opposite sides of said stationary member.

Claim 20

A disc brake comprising a rotatable disc having first and second opposite faces, first and second fRiction pad assemblies for engagement respectively with said first and second opposite faces of said disc, a stationary member mounted adjacent to said first face of said disc, a yoke extending over a portion of the periphery of said disc and mounted for sliding movement relative to said stationary member, and an hydraulic actuator adapted to apply said first friction pad assembly directly to said first face of said disc and adapted to apply said second friction pad assembly to said second face of said disc through said yoke, said yoke comprising a one-piece assembly having on one side a substantially lunar face substantially encompassing said stationary member and said portion of said periphery of said disc, said yoke including a first pair of spaced parallel lugs which both project away from the substantially planar face of said yoke in the same direction and of which the inner adjacent surfaces comprise a pair of spaced flat parallel guiding surfaces of substantial radial depth having a direct operative engagement with complementary flat guiding surfaces on opposite sides of said stationary member, and a second pair of spaced parallel lugs at right angles to said first pair and projecting away from the substantially planar face of said yoke in the same direction as said first pair, said lugs of said second pair being spaced outwardly beyond the outer opposite ends of said lugs of said first pair and being disposed between and located inwardly from spaced parallel planes containing said flat parallel guiding surfaces of said lugs of said first pair, and the adjacent inner faces of said lugs of said second pair defining abutment surfaces engaging respectively with said second friction pad assembly and which said hydraulic actuator, and wherein bearing surfaces at the radially innermost and outermost ends of said parallel guiding surfaces straddle and engage slidably with complementary spaced shoulders on arms on opposite sides of said stationary member.

Claim 21

A disc brake as claimed in claim 17, wherein said shoulders on said stationary member are located at radially opposite ends of each arm.

Claim 22

A disc brake as claimed in claim 17, wherein said shoulders on said stationary member are located at radially opposite ends of opposed lugs extending outwardly from the arms.

Claim 23

A disc brake as claimed in claim 17, wherein wear resistant devices are interposed between the spaced parallel guiding surfaces on the yoke and the complementary guiding surfaces on the stationary member.

Claim 24

A disc brake as claimed in claim 17, wherein said hydraulic actuator comprises a pair of opposed pistons working in a cylinder bore in said stationary member and one of the pistons acts directly on one of said second pair of spaced lugs on said yoke to move said yoke in a direction to apply said second friction pad assembly to the disc, the said one piston having a spigot portion located in an opening in the said one of said second pair of lugs, and a resilient annular sleeve being located between said opening and said spigot portion to compensate for tolerance variations between said spigot portion and said opening.

Claim 25

A disc brake as claimed in claim 21, wherein said resilient sleeve is constructed from a synthetic plastics material.