Multi-plate disc brakes for vehicles

Claim 2

A disc brake of the multi-plate type for vehicles comprising a housing, stationary and rotatable braking members located in said housing of which one of said braking members comprises a first pump member, applying means for urging said braking members into engagement to apply the brake, and a second pump member located within said housing and defining with said first pump member pump means, each pump member provided with passage means defining a path for liquid flow through that member in a generally radial direction, at least when said brake is applied, said passage means in said pump members being constructed and arranged so that when said pump members are rotating relatively to each other, liquid is circulated through said housing and over said braking members in a generally radial direction, said second pump member being floatingly mounted within said housing and rotatable with respect to both said stationary and rotatable braking members.

Claim 3

A disc brake as claimed in claim 1, wherein said passage means in said pump members interconnect inner and outer peripheral edges thereof.

Claim 4

A disc brake as claimed in claim 1, wherein said passage means comprises radial passages contained wholly within the effective axial thickness of each pump member.

Claim 5

A disc brake as claimed in claim 1, wherein coupling means are provided for coupling said first pump member to said housing against rotation relative thereto.

Claim 6

A disc brake as claimed in claim 4, wherein said housing is stationary and said second pump member is driven by frictional engagement with said rotatable braking members when said applying means are operated to apply said brake.

Claim 7

A disc brake as claimed in claim 4, wherein said housing is rotatable and said second pump member is normally rotatable with the said rotatable braking members and is frictionally engaged with said stationary braking members wHen said applying means are operated to apply said brake.

Claim 8

A disc brake as claimed in claim 1, wherein said first pump member comprises a set of braking members coupled to said housing and said passage means in said braking members of said set comprise gaps between circumferentially spaced areas of friction material which are carried thereby and which engage with the other said braking members when the brake is applied.

Claim 9

A disc brake as claimed in claim 7, wherein said friction material is in the form of circumferentially spaced portions of generally segmental outline which are secured to opposite faces of each said braking member.

Claim 10

A disc brake as claimed in claim 7, wherein said friction material comprises blocks received in complementary shaped apertures in each said braking member.

Claim 11

A disc brake as claimed in claim 1, wherein each braking member comprises inner and outer annular portions and torque transmitting means couple together adjacent peripheral edges of said inner and outer annular portions, said torque transmitting means being constructed and arranged to permit relative movement to take place in radial and axial directions to compensate for distortion of said braking members when heated.

Claim 12

A disc brake as claimed in claim 10, wherein said applying means includes load proportioning means which act on said inner and outer annular portions.

Claim 13

A disc brake as claimed in claim 11, wherein said load proportioning means comprises a torsionally resilient annular member having separate thrust applying parts acting on said inner and outer annular portions.

Claim 14

A disc brake as claimed in claim 12, wherein said annular member comprises an annular piston working in an hydraulic bore.

Claim 15

A disc brake as claimed in claim 1, wherein said second pump member is disposed between adjacent pairs of braking members, said second pump member including inner and outer annular portions, and torque transmitting coupling means coupling together adjacent peripheral edges of said inner and outer annular portions of said second pump member.

Claim 16

A disc brake as claimed in claim 14, wherein said torque transmitting means comprises interengaging circumferentially extending teeth provided in said adjacent mating peripheral edges.

Claim 17

A disc brake of the multi-plate type for vehicles comprising a stationary housing, a part rotatable relative to said housing, rotatable braking members in said housing rotatable with said part, stationary braking members in said housing coupled to said housing and adapted to be engaged by said rotatable braking members, applying means for urging said rotatable and stationary braking members into engagement to apply said brake, and a pump impeller located in said housing between an adjacent pair of said rotatable braking members and provided with passage means defining a path for liquid flow through said impeller in a radially outwards direction when said impeller is rotating with said pair of rotatable braking members being provided with passage means defining a path for liquid flow in a generally radially inward direction when said impeller is rotating with the said pair of rotatable braking members, said passage means in each stationary braking member being coupled on one side by a face of a rotatable braking member with which said stationary braking member is adapted to engage when the brake is applied whereby liquid is applied directly to heated braking faces, and said impeller being floatingly mounted in said housing and rotatable with respect to both said stationary and rotatable braking members to balance any centrifugal hydraulic head generated between said braking members in an off position of brake.

Claim 18

A disc brake of the multi-plate type for vehicles comprising a stationary housing, a part rotatable relative to said housing, rotatable braking members in said housing rotatable with said part, stationary braking members in said housing coupled to said housing and adapted to be engaged by said rotatable braking members, applying means for urging said rotatable and stationary braking members into engagement to apply said brake, and a pump impeller located in said housing between an adjacent pair of said rotatable braking members and provided with passage means defining a path for liquid flow through said impeller in a radially outwards direction when said impeller is rotating with said pair of rotatable braking members being provided with passage means defining a path for liquid flow in a generally radially inward direction when said impeller is rotating with the said pair of rotatable braking members, said passage means in each stationary braking member being coupled on one side by a face of a rotatable braking member with which said stationary braking member is adapted to engage when the brake is applied whereby liquid is applied directly to heated braking faces, and said impeller being floatingly mounted in said housing and rotatable with respect to both said stationary and rotatable braking members to balance any centrifugal hydraulic head generated between said braking members in an off position of brake.

Claim 19

A disc brake of the multi-plate type for vehicles comprising a fixed part, a rotatable housing rotatable relative to said fixed part, stationary braking members in said housing coupled to said fixed part, rotatable braking members in said housing rotatable therewith and defining a pump impeller, opPosed clamp members mounted in said housing and disposed between opposite end walls of said housing and a pair of said stationary members which are outermost, and means for urging said clamp members towards each other to urge said braking members into engagement to apply said brake, said rotatable braking member being provided with passage means defining a path for liquid flow in a generally radially outward direction, and each clamp member being provided with passage means defining a path for liquid flow in a generally radially inward direction when said impeller is rotating, said passage means in each rotatable braking member being bounded on one side by a face of a stationary braking member which is adapted to engage therewith when the brake is applied whereby liquid is applied directly to heated braking faces, and said clamp members being floatingly mounted in said housing and rotatable with respect to both said stationary and rotatable braking members to balance any centrifugal hydraulic head generated between said braking members in an off position of brake.

Claim 20

A disc brake of the multi-plate type for vehicles comprising a fixed part, a rotatable housing rotatable relative to said fixed part, stationary braking members in said housing coupled to said fixed part, rotatable braking members in said housing rotatable therewith and defining a pump impeller, opPosed clamp members mounted in said housing and disposed between opposite end walls of said housing and a pair of said stationary members which are outermost, and means for urging said clamp members towards each other to urge said braking members into engagement to apply said brake, said rotatable braking member being provided with passage means defining a path for liquid flow in a generally radially outward direction, and each clamp member being provided with passage means defining a path for liquid flow in a generally radially inward direction when said impeller is rotating, said passage means in each rotatable braking member being bounded on one side by a face of a stationary braking member which is adapted to engage therewith when the brake is applied whereby liquid is applied directly to heated braking faces, and said clamp members being floatingly mounted in said housing and rotatable with respect to both said stationary and rotatable braking members to balance any centrifugal hydraulic head generated between said braking members in an off position of brake.

Claim 21

A disc brake of the multi-plate type for vehicles comprising a stationary housing, a part rotatable relative to said housing, rotatable braking members in said housing rotatable with said part, clutch means for transmitting rotation of said part to said rotatable braking members, stationary braking members in said housing coupled to said housing, applying means for urging said rotatable and stationary braking members into engagement to apply said brake, and a pump impeller floatingly mounted in said housing between an adjacent pair of said rotatable braking members and provided with passage means defining a path for liquid flow through said impeller, in a generally radially outward direction when said impeller is rotating with respect to said stationary braking members, said stationary braking members being provided with passage means defining a path for liquid flow in a generally radially inward direction when said impeller is rotating, and means being incorporated for holding said clutch means in a disengaged position in which said rotatable members do not rotate with said part unless and until said applying means are operated, said passage means being so constructed and arranged that when said applying means are operated said pump impeller rotates with respect to said stationary braking members and liquid is circulated through said housing and over said braking members in a generally radial direction, and said impeller being rotatable with respect to both said stationary and rotatable braking members to balance any hydraulic head generated between said braking members in an off position of brake.

Claim 22

A disc brake of the multi-plate type for vehicles comprising a stationary housing, a part rotatable relative to said housing, rotatable braking members in said housing rotatable with said part, clutch means for transmitting rotation of said part to said rotatable braking members, stationary braking members in said housing coupled to said housing, applying means for urging said rotatable and stationary braking members into engagement to apply said brake, and a pump impeller floatingly mounted in said housing between an adjacent pair of said rotatable braking members and provided with passage means defining a path for liquid flow through said impeller, in a generally radially outward direction when said impeller is rotating with respect to said stationary braking members, said stationary braking members being provided with passage means defining a path for liquid flow in a generally radially inward direction when said impeller is rotating, and means being incorporated for holding said clutch means in a disengaged position in which said rotatable members do not rotate with said part unless and until said applying means are operated, said passage means being so constructed and arranged that when said applying means are operated said pump impeller rotates with respect to said stationary braking members and liquid is circulated through said housing and over said braking members in a generally radial direction, and said impeller being rotatable with respect to both said stationary and rotatable braking members to balance any hydraulic head generated between said braking members in an off position of brake.

Claim 23

A disc brake as claimed in claim 18, wherein an operating spring is adapted to urge said clutch means into said engaged position, and said clutch means includes hydraulic pressure responsive means normally adapted to be subjected to hydraulic pressure to hold said clutch means in said disengaged position in opposition to the force of said operating spring, said clutch means being engaged automatically upon release of said hydraulic pressure.

Claim 24

A disc brake as claimed in claim 1, wherein said housing is provided with inlet and outlet ports by means of which said housing is connected to a reservoir for liquid which acts as a heat exchanger for heated liquid which is pumped and circulated therethrough.