Clearance sensing brake adjuster

Claim 2

An adjuster for automatically controlling clearance within predetermined limits between first and second relatively moveable friction members which are engaged to diminish such relative movement in response to movement of actuator means in one direction and which are disengaged to allow such relative movement in response to movement of the actuator means in another direction, said adjuster comprising: adjustable means moveable in a clearance decreasing direction and in a clearance increasing direction; adjusting means for moving said adjustable means in said clearance decreasing direction in response to movement of said actuator means in one of said engaging and disengaging directions and in said clearance increasing direction in response to movement of said actuator means in the other of said engaging and disengaging directions; force limiting means for preventing movement of said adjustable means by said adjusting means when the force required for moving said adjustable means exceeds the force limit of said force limiting means; and a device operative to allow a predetermined maximum amount of movement of said adjustable means in one of said clearance adjusting directions during a portion of actuator movement in one of said engaging and disengaging directions and therefore operative to apply a force in excess of said force limit during the remainder of the actuator movement in said one of said engaging and disengaging directions for preventing further movement of said adjustable means in said one of said clearance adjusting directions.

Claim 3

The adjuster of claim 1, wherein said force limiting means comprises a two-way force limiting clutch having a greater force limit in one drive direction than in the other.

Claim 4

The adjuster of claim 2, wherein said operative device applies said force in excess when drive through said clutch is in the lower force direction.

Claim 5

The adjuster of claim 1, wherein said operative device comprises a roller clutch for applying said force in excess.

Claim 6

Adjuster of claim 1, wherein said force limiting means comprises a two-way force limiting ratchet clutch.

Claim 7

The adjuster of claim 5, wherein the force limit of said ratchet clutch is greater in one drive direction than in the other.

Claim 8

The adjuster of claim 6, wherein said operative device applies said force in excess when drive through said clutch is in the lower force direction.

Claim 9

The adjuster of claim 1, wherein said force limiting means comprises a two-way force limiting ratchet clutch and said operative device comprises a roller clutch for applying said force in excess.

Claim 10

The adjuster of claim 8, wherein the force limit of said ratchet clutch is greater in one drive direction than in the other.

Claim 11

The adjuster of claim 9, wherein said roller clutch applies said force in excess when drive through said ratchet clutch is in the lower force direction.

Claim 12

The adjuster of claim 1, wherein said adjusting means moves said adjustable means in said clearance decreasing direction in response to movement of said actuator means in the direction for engaging said friction members.

Claim 13

The adjuster of claim 11, wherein said force limiting means comprises a two-way force limiting clutch having a greater force limit in one drive direction than in the other.

Claim 14

The adjuster of claim 12, wherein said operative device applies said force in excess when drive through said clutch is in the lower force direction.

Claim 15

The adjuster of claim 12, wherein said operative device comprises a roller clutch operative to apply said force in excess which drive through said force limiting clutch is in the lower force direction.

Claim 16

An automatic clearance adjuster for controlling clearance within predetermined limits between first and second relatively rotatable friction members which are engaged and disengaged respectively to diminish and allow such relative rotation in response to pivotal movement of a lever defining a housing, said adjuster comprising: a first gear rotatably disposed in said housing and adapted to move one of said friction members into said engagement and disengagement when rotated by said lever and adapted to adjust said clearance when rotated relative to said lever; a second gear rotatably disposed in said housing and in mesh with said first gear, said second gear operative to adjustably lock said first gear to said lever for effecting said engagement and disengagement, and said second gear rotatable relative to said lever in clearance decreasing and increasing directions of rotation to respectively effect clearance decreasing and increasing rotation of said first gear; adjusting means for effecting said clearance decreasing rotation of said second gear in response to pivotal movement of said lever in one direction and for effecting clearance increasing rotation of said second gear in response to pivotal movement of said lever in the other direction; a torque limiting clutch for preventing said clearance decreasing and increasing rotation when the torque required to rotate said second gear relative to said lever exceeds the torque limit of said clutch; and a device operative to allow a predetermined maximum amount of clearance rotation of said second gear in one of said clearance adjusting directions during a portion of pivotal movement of said lever in one of said directions and thereafter operative to apply a torque in excess to the torque limit of said clutch for preventing further rotation of said second gear in said one of said clearance adjusting directions.

Claim 17

An automatic clearance adjuster for controlling clearance within predetermined limits between first and second relatively rotatable friction members which are engaged and disengaged respectively to diminish and allow such relative rotation in response to pivotal movement of a lever defining a housing, said adjuster comprising: a first gear rotatably disposed in said housing and adapted to move one of said friction members into said engagement and disengagement when rotated by said lever and adapted to adjust said clearance when rotated relative to said lever; a second gear rotatably disposed in said housing and in mesh with said first gear, said second gear operative to adjustably lock said first gear to said lever for effecting said engagement and disengagement, and said second gear rotatable relative to said lever in clearance decreasing and increasing directions of rotation to respectively effect clearance decreasing and increasing rotation of said first gear; adjusting means for effecting said clearance decreasing rotation of said second gear in response to pivotal movement of said lever in one direction and for effecting clearance increasing rotation of said second gear in response to pivotal movement of said lever in the other direction; a torque limiting clutch for preventing said clearance decreasing and increasing rotation when the torque required to rotate said second gear relative to said lever exceeds the torque limit of said clutch; and a device operative to allow a predetermined maximum amount of clearance rotation of said second gear in one of said clearance adjusting directions during a portion of pivotal movement of said lever in one of said directions and thereafter operative to apply a torque in excess to the torque limit of said clutch for preventing further rotation of said second gear in said one of said clearance adjusting directions.

Claim 18

The adjuster of claim 15, wherein said torque limiting clutch comprises a two-way torque limiting clutch having a greater torque limit in one drive direction than in the other.

Claim 19

The adjuster of claim 16, wherein said operative device applies said torque in excess when drive through said clutch is in the lower torque direction.

Claim 20

The adjuster of claim 15, wherein said operative device comprises a roller clutch for applying said torque in excess.

Claim 21

The adjuster of claim 15, wherein said operative device comprises: a roller clutch operative to allow said predetermined maximum amount of clearance rotation of said second gear and thereafter operative to lock-up and apply said torque in excess; and manual adjusting means operative to unlock said clutch, whereby said second gear may be manually rotated in said clearance decreasing and increasing directions.

Claim 22

The adjuster of claim 15, wherein said torque limiting clutch comprises a two-way torque limiting ratchet clutch.

Claim 23

The adjuster of claim 20, wherein said torque limit of said ratchet clutch is greater in one drive direction than in the other.

Claim 24

The adjuster of claim 21, wherein said operative device applies said torque in excess when drive through said clutch is in the lower torque direction.

Claim 25

The adjuster of claim 15, wherein said torque limiting clutch comprises a two-way torque limiting ratchet clutch and said operative device comprises a roller clutch for applying said torque in excess.

Claim 26

The adjuster of claim 23, wherein the torque limit of said ratchet clutch is greater in one drive direction than in the other.

Claim 27

The adjuster of claim 24, wherein said roller clutch applies said torque in excess when drive through said ratchet clutch is in the lower torque direction.

Claim 28

The adjuster of claim 15, wherein said adjusting means rotates said adjustable means in said clearance decreasing direction in response to pivotal movement of said lever in the direction for engaging said friction members.

Claim 29

The adjuster of claim 26, wherein said torque limiting clutch comprises a two-way torque limiting clutch having a greater torque limit in one drive direction than in the other.

Claim 30

The adjuster of claim 27, wherein said operative device applies said torque in excess when drive through said clutch is in the lower torque direction.

Claim 31

The adjuster of claim 27, wherein said operative device comprises a roller clutch operative to apply said torque in excess when drive through said torque limiting clutch is in the lower torque direction.

Claim 32

A brake clearance adjuster including a reciprocatingly pivotal lever defining a housing having first and second intermeshed gears disposed therein and a torque limiting clutch drivingly connected to said second gear, said second gear operative to rotate said first gear with said lever in response to said pivotal movement of said lever for applying and releasing the brake, said torque limiting clutch operative to reciprocatingly rotate said gears relative to said lever in response to said pivotal movement of said lever for effecting clearance decreasing and increasing adjustments of said brake when the torque required to rotate said gears is below the torque limit of said clutch, wherein the improvement comprises: a device operative to allow a predetermined amount of rotation of said second gear in one direction relative to said lever by said clutch during a portion of said pivotal movement of said lever in one direction and thereafter operative to prevent such rotation of said second gear during continued pivotal movement of said lever in said one direction.

Claim 33

A brake clearance adjuster including a reciprocatingly pivotal lever defining a housing having first and second intermeshed gears disposed therein and a torque limiting clutch drivingly connected to said second gear, said second gear operative to rotate said first gear with said lever in response to said pivotal movement of said lever for applying and releasing the brake, said torque limiting clutch operative to reciprocatingly rotate said gears relative to said lever in response to said pivotal movement of said lever for effecting clearance decreasing and increasing adjustments of said brake when the torque required to rotate said gears is below the torque limit of said clutch, wherein the improvement comprises: a device operative to allow a predetermined amount of rotation of said second gear in one direction relative to said lever by said clutch during a portion of said pivotal movement of said lever in one direction and thereafter operative to prevent such rotation of said second gear during continued pivotal movement of said lever in said one direction.

Claim 34

The brake adjuster of claim 30, wherein said device comprises a roller clutch operative to allow said predetermined amount of rotation of said second gear in said one direction and thereafter operative to lock-up and prevent said rotation in response to said predetermined amount of rotation of said second gear in said one direction.

Claim 35

The brake adjuster of claim 30, wherein said device comprises: a roller clutch operative to allow said predetermined amount of rotation of said second gear in said one direction and thereafter operative to lock-up and prevent said rotation in response to said predetermined amount of rotation of said second gear in said one direction; and manual adjusting means operative to unlock said clutch, whereby said second gear may be manually rotated in either direction.

Claim 36

The brake adjuster of claim 30, wherein said torque limiting clutch comprises a two-way torque limiting clutch having a lower torque limit in the drive direction for rotating said second gear in said one direction.

Claim 37

The brake adjuster of claim 30, wherein said torque limiting ratchet clutch comprises a two-way torque limiting ratchet clutch.

Claim 38

The brake adjuster of claim 34, wherein the torque limit of said ratchet clutch is greater in one direction than in the other.

Claim 39

The brake adjuster of claim 35, wherein said device comprises a roller clutch operative in the low torque drive direction of said ratchet clutch to allow said predetermined amount of rotation of said second gear in said one direction and thereafter operative to lock-up and prevent said rotation in said one direction.

Claim 40

The brake adjuster of claim 36, wherein said ratchet clutch rotates said second gear in said clearance decreasing direction in response to pivotal movement of said lever in the brake apply direction.