Brake mechanism

Claim 2

A brake mechanism for association with a brakedrum to effect braking of the brakedrum, said brake mechanism comprising a pair of brakeshoes for mounting in said drum and displaceable from an initial position to contact said drum, each of said brakeshoes having first and second ends, the first ends of said brakeshoes being adjacent each other and the second ends of said brakeshoes being adjacent each other, abutment means abuttingly engaging the respective first ends of said brakeshoes, and actuator means for effecting outward displacement of said second ends of said brakeshoes an equal amount into engagement with the brakedrum and for maintaining said second ends of said brakeshoes displaced equal distance from the initial position during braking, said actuator means including wedge means movable to effect said displacement, said wedge means effecting and maintaining equal displacement of said second ends of said brakeshoes by the application of unequal forces to said brakeshoes to overcome the self-energizing effect of the brakeshoes.

Claim 3

A brake mechanism as defined in claim 1 wherein said actuator means includes a pair of wedge projections which cooperate with the respective second ends of said brakeshoes to effect equal movement thereof during braking, and further including fluid operated power means for effecting simultaneous movement of said wedge projections.

Claim 4

A brake mechanism as defined in claim 2 further including a support plate means for said brake mechanism and an anchor secured to said support plate means and located between said wedge projections in bearing relationship therewith.

Claim 5

A brake mechanism as defined in claim 3 further including a roller cage carrying a plurality of rollers interposed between surfaces on said wedge projections and surfaces on said anchor means.

Claim 6

A brake mechanism as defined in claim 4 further including separate plunger members associated with said second ends of said brakeshoes to effect movement of said second ends of said brakeshoes upon movement thereof and wherein said roller cage further carries rollers interposed between said wedge members and said plunger members.

Claim 7

A brake mechanism as defined in claim 3 wherein said support plate means comprises a pair of generally rectangular sheet metal elements joined together to form a double-thickness member defining a first plane, an axle receiving aperture in said double-thickness member and offset portions at one end of said double-thickness member providing a support for supporting said actuator means.

Claim 8

A brake mechanism as defined in claim 1 further including means responsive to brake lining wear for effecting equal and simultaneous adjustment of said brakeshoes.

Claim 9

A brake mechanism as defined in claim 7 wherein said abutment means comprises a pair of cam members engageable with the ends of said brakeshoes and said adjustment means comprises means for effecting rotation of said cam members simultaneously and equally to effect said brakeshoe adjustment.

Claim 10

A brake mechanism as defined in claim 3 wherein said support plate means is adapted to be secured to a vehicle axle housing and further including spacer means separate from said support plate means and the axle housing and interposed between said support plate means and the axle housing to locate said support plate means with respect to said axle housing, and fastener means for securing said support plate means, spacer means and axle housing together.

Claim 11

A brake mechanism for association with a vehicle having a brakedrum carried by a vehicle axle and an axle housing, said brake mechanism comprising a pair of brakeshoes, support means supporting said brakeshoes for displacement to contact said drum, actuator means for effecting displacement of said brakeshoes, said support means comprising support plate means encircling said axle, and spacer means separate from said supporT plate means and the axle housing for location between said support plate means and the axle housing for location between said support plate means and the axle housing to locate said support plate means with respect to said axle, and fastener means for securing said support plate means, spacer means and axle housing together, with spacer means being in the form of a ring which encircles said axle and having openings provided therethrough for receipt of said fastener means.

Claim 12

A brake mechanism for association with a vehicle having a brakedrum carried by a vehicle axle and an axle housing, said brake mechanism comprising a pair of brakeshoes, support means supporting said brakeshoes for displacement to contact said drum, actuator means for effecting displacement of said brakeshoes, said support means comprising support plate means encircling said axle, and spacer means separate from said supporT plate means and the axle housing for location between said support plate means and the axle housing for location between said support plate means and the axle housing to locate said support plate means with respect to said axle, and fastener means for securing said support plate means, spacer means and axle housing together, with spacer means being in the form of a ring which encircles said axle and having openings provided therethrough for receipt of said fastener means.

Claim 13

A brake mechanism for association with a vehicle having a brakedrum carried by a vehicle axle and an axle housing, said brake mechanism comprising a pair of brakeshoes, support means supporting said brakeshoes for displacement to contact said drum, actuator means for effecting displacement of said brakeshoes, said support means comprising support plate means encircling said axle, and spacer means separate from said support plate means and the axle housing for location between said support plate means and the axle housing to locate said support plate means with respect to said axle, and fastener means for securing said support plate means, spacer means and axle housing together.

Claim 14

A brake mechanism for association with a vehicle having a brakedrum carried by a vehicle axle and an axle housing, said brake mechanism comprising a pair of brakeshoes, support means supporting said brakeshoes for displacement to contact said drum, actuator means for effecting displacement of said brakeshoes, said support means comprising support plate means encircling said axle, and spacer means separate from said support plate means and the axle housing for location between said support plate means and the axle housing to locate said support plate means with respect to said axle, and fastener means for securing said support plate means, spacer means and axle housing together.

Claim 15

A brake mechanism as defined in claim 11 wherein said actuator means comprises a wedge actuator means movable to effect equal displacement of adjacent ends of said brakeshoes.

Claim 16

A brake mechanism as defined in claim 11 wherein said support plate means comprises a sheet metal plate having a portion for supporting said actuator means and said support plate being located generally centrally of said brakeshoes.

Claim 17

A brake mechanism for association with a brakedrum carried by a vehicle axle having an axle flange, said brake mechanism comprising a backing plate adapted to be secured to said axle flange, a pair of opposed expanding brakeshoes for mounting within said drum, and means for spreading said opposed expanding brakeshoes to contact with said brakedrum, said backing plate comprising a pair of generally rectangular thin sheet metal elements joined together to form a double-thickness member defining a first plane, an axle receiving aperture in said double-thickness member surrounded by a plurality of bolt receiving holes, offset portions at one end of said double-thickness member defining at least one plane parallel to said first plane and offset therefrom, and means on said offset portions for receiving said means for spreading said opposed expanding brakeshoes.

Claim 18

A brake mechanism for association with a brakedrum carried by a vehicle axle having an axle flange, said brake mechanism comprising a backing plate adapted to be secured to said axle flange, a pair of opposed expanding brakeshoes for mounting within said drum, and means for spreading said opposed expanding brakeshoes to contact with said brakedrum, said backing plate comprising a pair of generally rectangular thin sheet metal elements joined together to form a double-thickness member defining a first plane, an axle receiving aperture in said double-thickness member surrounded by a plurality of bolt receiving holes, offset portions at one end of said double-thickness member defining at least one plane parallel to said first plane and offset therefrom, and means on said offset portions for receiving said means for spreading said opposed expanding brakeshoes.

Claim 19

A brake mechanism as defined in claim 14 wherein said means for spreading said brakeshoes comprises a pair of wedge projections which cooperate with adjacent ends of said brakeshoes to effect equal movement thereof during braking and further including fluid operated power means for effecting simultaneous movement of said wedge projections.

Claim 20

A brake mechanism for association with a brakedrum to effect braking of the brakedrum, said brake mechanism comprising a pair of brakeshoes for mounting in said drum and displaceable to contact said drum, each of said brakeshoes having first and second ends, the first ends of said brakeshoes being adjacent each other and the second ends of said brakeshoes being adjacent each other, abutment means contacting the respective first ends of said brakeshoes, and actuator means for effecting equal outward displacement of said second ends of said brakeshoes during braking, said abutment means and said actuator means having cooperating floating engagements with said respective ends of said brakeshoes and applying forces to said brakeshoes to provide maximum brakeshoe wear near the center thereof and to produce a minimization of brakeshoe and brakedrum distortion, said actuator means comprising wedge means for effecting said equal displacement and maintaining said equal displacements during braking.

Claim 21

A brake mechanism for association with a brakedrum to effect braking of the brakedrum, said brake mechanism comprising a pair of brakeshoes for mounting in said drum and displaceable to contact said drum, each of said brakeshoes having first and second ends, the first ends of said brakeshoes being adjacent each other and the second ends of said brakeshoes being adjacent each other, abutment means contacting the respective first ends of said brakeshoes, and actuator means for effecting equal outward displacement of said second ends of said brakeshoes during braking, said abutment means and said actuator means having cooperating floating engagements with said respective ends of said brakeshoes and applying forces to said brakeshoes to provide maximum brakeshoe wear near the center thereof and to produce a minimization of brakeshoe and brakedrum distortion, said actuator means comprising wedge means for effecting said equal displacement and maintaining said equal displacements during braking.

Claim 22

A brake mechanism for association with a brakedrum to effect braking of the brakedrum, said brake mechanism comprising a pair of brakeshoes, support means supporting said brakeshoes for displacement to contact said drum, each of said brakeshoes having first and second ends, actuator means interposed between opposed second ends of the brakeshoes to effect displacement of the brakeshoes upon actuation thereof, first and second rotatable cam members engaging said respective first ends of said brakeshoes and which upon rotation position the brakeshoes closer to the brakedrum, and drive means for simultaneously rotating said cam members to position said brakeshoes closer to the brakedrum in response to a predetermined amount of movement of said brakeshoes toward the brakedrum.

Claim 23

A brake mechanism for association with a brakedrum to effect braking of the brakedrum, said brake mechanism comprising a pair of brakeshoes, support means supporting said brakeshoes for displacement to contact said drum, each of said brakeshoes having first and second ends, actuator means interposed between opposed second ends of the brakeshoes to effect displacement of the brakeshoes upon actuation thereof, first and second rotatable cam members engaging said respective first ends of said brakeshoes and which upon rotation position the brakeshoes closer to the brakedrum, and drive means for simultaneously rotating said cam members to position said brakeshoes closer to the brakedrum in response to a predetermined amount of movement of said brakeshoes toward the brakedrum.

Claim 24

A brake mechanism as defined in claim 17 wherein said means for effecting rotation of said cam members comprises a pair of relatively pivotal links, one of said links being movable upon actuation of said actuator means and the other of said links cooperating with said cam members to effect rotation thereof, spring means biasing said links apart and providing for pivotal movement of said links as a unit until said brakeshoes engage said brakedrum and enabling movement of said one link relative to the other thereafter.

Claim 25

A brake mechanism as defined in claim 18 wherein said drive means includes gears associated with said other link for rotation upon movement thereof, said gears being positioned to effect rotation of said cams upon rotation thereof.

Claim 26

A brake mechanism as defined in claim 17 wherein said drive means comprises meshing gears connected with said respective cam members and means for rotating said gears in response to a predetermined amount of movement of the brakeshoes toward the brakedrum.

Claim 27

A brake mechanism for association with a vehicle having a brakedrum carried by a vehicle axle, said brake mechanism comprising a pair of brakeshoes, actuator means interposed between adjacent ends of said brakeshoes for effecting displacement thereof for braking, said actuator means including at least one wedge member movable generally parallel to the axle of the vehicle and fluid-operated power means for moving said wedge member, said fluid-operated power means being divergently mounted with respect to said vehicle axle and being operable to impart motion to move said wedge axially of the vehicle axle to effect displacement of said brakeshoes.

Claim 28

A brake mechanism for association with a vehicle having a brakedrum carried by a vehicle axle, said brake mechanism comprising a pair of brakeshoes, actuator means interposed between adjacent ends of said brakeshoes for effecting displacement thereof for braking, said actuator means including at least one wedge member movable generally parallel to the axle of the vehicle and fluid-operated power means for moving said wedge member, said fluid-operated power means being divergently mounted with respect to said vehicle axle and being operable to impart motion to move said wedge axially of the vehicle axle to effect displacement of said brakeshoes.

Claim 29

A brake mechanism as defined in claim 21 wherein said fluid-operated power means includes a reciprocating output member which is movable in an angular direction relative to the vehicle axle, means pivotally connecting said output member and said wedge member, and means for guiding movement of said wedge member axially of the vehicle axle upon movement of said output member.

Claim 30

A brake mechanism as defined in claim 22 wherein said actuator means effects outward displacement of the brakeshoes an equal amount and maintains said brakeshoes displaced equal distances from their initial positions during braking.

Claim 31

A brake mechanism for association with a brakedrum to effect braking of the drum, said braking mechanism comprising a pair of brakeshoes for mounting in the drum and displaceable from an initial position to contact the drum, one of the shoes being a leading and one a trailing shoe, each of the brakeshoes having first and second ends, the first ends of the shoes being positioned adjacent to each other and the second ends of the shoes being positioned adjacent to each other, abutment means abuttingly engaging the first ends of the shoes for adjusting the running clearances of the shoes relative to the drum, brake application actuator means interposed between the opposed second ends of the brakeshoes for effecting displacement of the second ends an equal amount to displace the shoes into engagement with the drum and for maintaining said second ends displaced equal distances from the initial position during braking, said brake application actuator means comprising wedge means interposed between the second ends of said shoes and movable between said second ends to displace the shoes into drum engaging, brake applying relation, and fixed anchor means cooperating with said wedge means, preventing lateral movement of the wedge means as the result of unequal brake reaction forces of the leading and trailing shoes, and said anchor means in combination with said wedge means effecting and maintaining equal displacement of the second ends of the shoes by the application of unequal forces to the shoes to overcome the self-energizing effects of the respective shoes.

Claim 32

A brake mechanism for association with a brakedrum to effect braking of the drum, said braking mechanism comprising a pair of brakeshoes for mounting in the drum and displaceable from an initial position to contact the drum, one of the shoes being a leading and one a trailing shoe, each of the brakeshoes having first and second ends, the first ends of the shoes being positioned adjacent to each other and the second ends of the shoes being positioned adjacent to each other, abutment means abuttingly engaging the first ends of the shoes for adjusting the running clearances of the shoes relative to the drum, brake application actuator means interposed between the opposed second ends of the brakeshoes for effecting displacement of the second ends an equal amount to displace the shoes into engagement with the drum and for maintaining said second ends displaced equal distances from the initial position during braking, said brake application actuator means comprising wedge means interposed between the second ends of said shoes and movable between said second ends to displace the shoes into drum engaging, brake applying relation, and fixed anchor means cooperating with said wedge means, preventing lateral movement of the wedge means as the result of unequal brake reaction forces of the leading and trailing shoes, and said anchor means in combination with said wedge means effecting and maintaining equal displacement of the second ends of the shoes by the application of unequal forces to the shoes to overcome the self-energizing effects of the respective shoes.

Claim 33

The invention of claim 24 wherein said wedge means comprises a bifurcated wedge and said anchor means is embraced by said wedge, and including antifriction means between the wedge and anchor and antifriction means between the wedge and said second ends of the shoes.

Claim 34

A brake mechanism for association with a brake drum to effect braking of the drum, said brake mechanism comprising a pair of brakeshoes one of which is a leading and one a trailing shoe, support means supporting said brakeshoes for displacement to contact the drum, each of said shoes having first and second ends, respectively opposed to one another, brake application actuator means interposed between opposed second ends of the brakeshoes, the brake application actuator means including wedge means interposed between the second ends to effect displacement of the shoes an equal amount upon actuation of the actuator means, fixed anchor means between opposed first ends of the brakeshoes and means mounting first and second movable adjuster members to said anchor means and engaging said first ends of the shoes, said adjuster members being effective on movement to adjust the brakeshoes closer to the brakedrum and thereby maintain accurate running clearance, and drive means for simultaneously moving said adjuster members to adjust both brakeshoes closer to the drum in response to a predetermined amount of brake application movement of the brakeshoes toward the brakedrum, and said drive means being responsive to brake lining wear.

Claim 35

A brake mechanism for association with a brake drum to effect braking of the drum, said brake mechanism comprising a pair of brakeshoes one of which is a leading and one a trailing shoe, support means supporting said brakeshoes for displacement to contact the drum, each of said shoes having first and second ends, respectively opposed to one another, brake application actuator means interposed between opposed second ends of the brakeshoes, the brake application actuator means including wedge means interposed between the second ends to effect displacement of the shoes an equal amount upon actuation of the actuator means, fixed anchor means between opposed first ends of the brakeshoes and means mounting first and second movable adjuster members to said anchor means and engaging said first ends of the shoes, said adjuster members being effective on movement to adjust the brakeshoes closer to the brakedrum and thereby maintain accurate running clearance, and drive means for simultaneously moving said adjuster members to adjust both brakeshoes closer to the drum in response to a predetermined amount of brake application movement of the brakeshoes toward the brakedrum, and said drive means being responsive to brake lining wear.

Claim 36

The invention of claim 26 wherein said brake application actuator means further comprises fixed anchor means cooperating with said wedge means preventing lateral movement of the wedge means as the result of unequal brake reaction forces of the leading and trailing shoes.

Claim 37

The invention of claim 26 wherein said adjuster members comprise a pair of rotatable cams associated with the fixed anchor means, each cam abutting a respective first end of a brakeshoe and said drive means being adapted to simultaneously rotate said cams an equal amount to equally decrease the clearance between the brakedrum and the lining of each of the brakeshoes.

Claim 38

The invention according to claims 24 wherein the braking mechanism is carried by a vehicle axle having an axle flange, and the braking mechanism includes a backing plate adapted to be secured to said axle flange, said backing plate having a body lying in a first plane, an axle receiving aperture in the body and means for securing said body to the axle flange, a pair of spaced suspension points spaced radially outwardly from said axle receiving aperture and displaced axially to each side of the plane of said body, the brake application actuator means including means for engaging and spreading the brakeshoes into contact with the drum, and means mounting said brakeshoe spreading means by and between said suspension points so that thrust forces from said brakeshoe spreading means are absorbed between the suspension points and thus into said backing plate thereby substantially eliminating bending stresses in the baking plate body.

Claim 39

The invention of claim 29 wherein said backing plate comprises a pair of sheet metal elements joined together to form said body having the axle receiving aperture, each element having an offset portion thereby providing said pair of axially spaced suspension points spaced to each side of the plane of the body, said braking mechanism including adjuster means for adjusting the running clearance between the shoes and the drum, The backing plate having additional radially spaced suspension points, displaced axially to each side of the plane of said body, said additional suspension points being oriented generally diametrically opposite to the means for mounting the brakeshoe spreading means, and means mounting said adjuster means by and between said additional suspension points so that thrust forces from said adjuster means are absorbed between the suspension points and into the body of the backing plate without lateral bending stresses in the backing plate, and said additional suspension points being oriented generally opposite to the brakeshoe spreading means to provide a balance of forces across the body of the brake backing plate thereby avoiding bending stresses in the backing plate.

Claim 40

A brake mechanism for association with a brakedrum to effect braking of the brakedrum, said brake mechanism comprising a pair of brakeshoes, support means supporting said brakeshoes for displacement to contact said drum, each of said shoes having first and second ends respectively positioned in opposed relation to one another, brake application actuator means including wedge means interposed between opposed second ends of the shoes to effect displacement of the shoes an equal amount during brake application engagement with the drum; and movable abutment means abuttingly engaging the first ends of the shoes for adjusting the running clearance of the shoes relative to the drum to compensate for brake lining wear, and means for moving said abutment means, operable on the brake application stroke of said brake application means.

Claim 41

A brake mechanism for association with a brakedrum to effect braking of the brakedrum, said brake mechanism comprising a pair of brakeshoes, support means supporting said brakeshoes for displacement to contact said drum, each of said shoes having first and second ends respectively positioned in opposed relation to one another, brake application actuator means including wedge means interposed between opposed second ends of the shoes to effect displacement of the shoes an equal amount during brake application engagement with the drum; and movable abutment means abuttingly engaging the first ends of the shoes for adjusting the running clearance of the shoes relative to the drum to compensate for brake lining wear, and means for moving said abutment means, operable on the brake application stroke of said brake application means.

Claim 42

The invention of claim 31 including anchor means preventing rotary movement of said abutment means and the shoes as the result of unequal brake reaction forces of the leading and trailing shoes, said anchor means in combination with said abutment means, effecting and maintaining equal displacement of said first ends of the shoes by application of unequal forces to the first ends to overcome the self-energizing effects of the respective shoes.

Claim 43

The invention of claim 31 wherein said means for moving said abutment means for adjusting the running clearance comprises one-way force limiting means between the brake application actuator means and said abutment means, said one-way force limiting means being operable in response to a predetermined amount of movement of said brakeshoes toward contact with the brake drum.

Claim 44

The invention of claim 31 wherein said means for moving said abutment means comprises a pair of relatively pivotal links, one of said links movable upon actuation of said actuator means and the other of said links cooperating with said abutment means to effect movement thereof, biasing means between said links and providing for pivotal movement of said links as a unit until said shoes engage the drum and enabling pivotal movement of said links relative to one another thereafter.

Claim 45

The invention of claim 34 wherein said abutment means comprises a pair of rotatable cams respectively engageable with said first ends of the shoes, a gear fixed to rotate with each cam and the gears being in meshed relation, said other link engaging one of said gears to rotate said bear on movement of said other link, and means for preventing rotation of said gears and cams in reverse adjustment direction.

Claim 46

The invention of claim 35 wherein the brake application actuator means further comprises fixed anchor means preventing lateral displacement of the wedge means and thereby preventing rotary displacement of the shoes as the result of unequal brake reaction forces of the leading and trailing shoes against the drum.

Claim 47

A brake mechanism for association with a brakedrum to effect braking of the drum, said brake mechanism comprising a pair of brakeshoes for mounting in said drum, and displaceable to contact the drum, one shoe being a loading shoe and the other a trailing shoe, each brakeshoe having first and second ends, the first ends of the shoes beIng adjacent to each other and the second ends being adjacent to each other, abutment means contacting the respective first ends of the shoes for brake adjustment purposes, and actuator means for effecting equal displacement of the second ends of the brakeshoes during braking, and said abutment means and said actuator means having cooperating floating engagements with the first and second ends of the brakeshoes respectively and both said abutment means and said actuator means being oriented to apply forces to the shoe ends in directions to impose maximum shoe to drum pressure near the centers of the shoes and provide minimum shoe and drum distortion wherein the brake actuator means comprises wedge means interposed between the second ends of the shoes and movable between the second ends to displace the shoes into drum engaging brake applying relation, and fixed anchor means preventing lateral movement of the wedge means and thus rotary movement of the shoes as the result of unequal brake reaction forces of the leading and trailing shoes, and contact means between the wedge means and the second ends of the brakeshoes, the wedge means and the contact means having engaging faces oriented to apply brake application forces through the second ends of the brakeshoes in directions vectored toward the central portions of the shoes, imposing maximum shoe to drum pressures near the centers of the shoes for maximum shoe and drum distortion.

Claim 48

A brake mechanism for association with a brakedrum to effect braking of the drum, said brake mechanism comprising a pair of brakeshoes for mounting in said drum, and displaceable to contact the drum, one shoe being a loading shoe and the other a trailing shoe, each brakeshoe having first and second ends, the first ends of the shoes beIng adjacent to each other and the second ends being adjacent to each other, abutment means contacting the respective first ends of the shoes for brake adjustment purposes, and actuator means for effecting equal displacement of the second ends of the brakeshoes during braking, and said abutment means and said actuator means having cooperating floating engagements with the first and second ends of the brakeshoes respectively and both said abutment means and said actuator means being oriented to apply forces to the shoe ends in directions to impose maximum shoe to drum pressure near the centers of the shoes and provide minimum shoe and drum distortion wherein the brake actuator means comprises wedge means interposed between the second ends of the shoes and movable between the second ends to displace the shoes into drum engaging brake applying relation, and fixed anchor means preventing lateral movement of the wedge means and thus rotary movement of the shoes as the result of unequal brake reaction forces of the leading and trailing shoes, and contact means between the wedge means and the second ends of the brakeshoes, the wedge means and the contact means having engaging faces oriented to apply brake application forces through the second ends of the brakeshoes in directions vectored toward the central portions of the shoes, imposing maximum shoe to drum pressures near the centers of the shoes for maximum shoe and drum distortion.