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US 5,012,901 AGranted
Self-energizing disc brakes
AssigneeLucas Industries public limited company
InventorsRoy Campbell, Anthony G. Price
Life of this patent
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AssigneeLucas Industries public limited company
InventorsRoy Campbell, Anthony G. Price
Estimating the term…
A compound disc brake comprises a pair of pressure plates with a ball and ramp camming mechanism, one of the plates comprises a driven plate keyed to a rotating axle shaft to be braked, and the other plate comprises an input plate carried from the driven plate by the camming mechanism. The input plate is of larger diameter than the driven plate with its radially outer region comprising a torque-transmitting mechanism which transmits torque applied to that region by primary braking device, which can be a spot brake, to the central region of the input plate. Retardation of the input plate by the primary braking device causes the pressure plates to separate axially and move into engagement with relatively stationary braking surfaces in a brake housing whereafter servo braking occurs. Various multi-plate embodiments are disclosed, including embodiments in which the torque-transmitting mechanism is a separate annular disc keyed to the outer peripheral edge of the servo plate. Other modifications of the pressure plates are also disclosed.
A self-energising disc brake assembly of the compound type comprising a housing, a rotatable shaft to be braked extending into said housing, spaced braking surfaces in said housing, first and second pressure plates located between said braking surfaces and having in adjacent faces thereof complementary oppositely inclined angularly spaced recesses of which edges define ramp surfaces, and camming means between said plates, said camming means comprising rolling bodies located in complementary pairs of said recesses, relative angular movement between the plates causing said plates to move axially apart and into engagement with said braking surfaces due to said rolling bodies riding said ramps, wherein said first plate comprises a driven plate having an outer peripheral edge, means coupling said driven plate to said rotatable shaft so that said plate is axially movable with respect to said shaft but angularly immovable relative thereto, and said second plate comprises an input plate carried from said driven plate by means of said camming means, said compound brake also comprising primary braking means provided in said housing to retard rotation of said input plate, and a secondary brake formed by said self-energising engagement of said pressure plates with said braking surfaces, actuation of said secondary brake being effected by application of said primary braking means to retard said input plate and so cause relative angular movement between said pressure plates, in turn causing said pressure plates to engage said braking surfaces whereby to initiate a self-energising braking action by said secondary brake, and wherein said input plate has an outer peripheral edge, and torque-transmitting means co-operates with said input plate, said torque-transmitting means comprising at least one annular ring extending radially outwards beyond said outer peripheral edge of said driven plate and having a radial friction surface beyond the said edge, and keying means keying said ring to said outer peripheral edge of said input plate for axial movement relative thereto, said primary braking means being adapted to apply a force to said radial friction surface of said torque-transmitting means substantially in an axial direction in order to retard said input plate.
A self-energising disc brake assembly of the compound type comprising a housing a rotatable shaft to be braked extending into said housing, spaced braking surfaces in said housing, first and second pressure plates located between said braking surfaces and having in adjacent faces thereof complementary oppositely inclined angularly spaced recesses of which edges define ramp surfaces, and camming means between said plates, said camming means comprising rolling bodies located in complementary pairs of said recesses, relative angular movement between the plates causing said plates to move axially apart and into engagement with said braking surfaces due to said rolling bodies riding said ramps, wherein said first plate comprises a driven plate having an outer peripheral edge, means coupling said driven plate to said rotatable shaft so that said plate is axially movable with respect to said shaft but angularly immovable relative thereto, and said second plate comprises an input plate carried from said driven plate by means of said camming means, said compound brake also comprising primary braking means provided in said housing to retard rotation of said input plate, and a secondary brake formed by said self-energising engagement of said pressure plates with said braking surfaces, actuation of said secondary brake being effected by application of said primary braking means to retard said input plate and so cause relative angular movement between said pressure plates, in turn causing said pressure plates to engage said braking surfaces whereby to initiate a self-energising braking action by said secondary brake, and wherein torque-transmitting means co-operates with said input plate and is angularly rigid with respect to said input plate, said torque-transmitting means extending radially outwards beyond said outer peripheral edge of said driven plate and having a radial friction surface beyond the said edge, said primary braking means being adapted to apply a force to said radial friction surface of said torque=transmitting means, and means incorporated in said primary braking means to apply said force to said radial friction surface only in an axial direction without a self-energising effect in order to retard said input brake.
Dependencies are inferred from the claim text.