Wheel speed sensor for an anti-skid vehicle braking system

Claim 2

An anti-skid vehicle braking system speed sensor for a wheel mounted on a hub for rotation relative to the vehicle, comprising; a housing adapted to be mounted on the hub for rotation therewith, a switch having a body with at least one set of contacts therein and a yieldably biased actuator carried by said body and movable to first and second positions to actuate said one set of contacts to open and closed states, said body being pivotally mounted in said housing at a point spaced from said actuator such that said actuator is moved from one of said positions to the other of said positions by pivotal movement of said body in relation to said housing in response to a change in the centrifugal force acting on said switch caused by a given change in the rotary speed of the hub and wheel.

Claim 3

The speed sensor of claim 1 in which said actuator comprises an arm extending generally radially of the hub with its free end adapted to bear on a surface of said housing radially outboard of said free end of said actuator arm.

Claim 4

The speed sensor of claim 1 in which said housing is adapted to be received and retained in a standard bore in the hub normally provided to receive a grease seal.

Claim 5

The speed sensor of claim 1 wherein the hub is mounted on a spindle for rotation and said housing includes a resilient seal adapted to engage a generally circular surface of the spindle to provide a grease seal between the spindle and the hub.

Claim 6

The speed sensor of claim 1 wherein the hub is mounted on a spindle for rotation and said housing includes a ring of an electrically conductive material mounted externally on said housing and adapted to encircle and be generally coaxial with the spindle, said ring of an electrically conductive material being electrically connected with one of said contacts of said switch.

Claim 7

The speed sensor of claim 5 which also comprises an electrically conductive brush adapted to be mounted in fixed relation to the spindle and in continuous electrical contact with said ring of an electrically conductive material carried by said housing.

Claim 8

The speed sensor of claim 1 in which said switch has a lever arm fixed adjacent one end to said body and a weight fixed to the free end of said arm, said arm extending generally radially outwardly from the pivotal axis of said body within the confines of said housing.

Claim 9

The speed sensor of claim 1 wherein the hub is mounted on a spindle for rotation and in which said housing comprises first and second circular members having generally axially extending cylindrical side walls adapted for telescoping engagement with each other and generally radially extending end walls being axially spaced in assembly, and a generally circular seal engaging and being carried by said axially spaced end walls, said seal being adapted to engage a circular surface of the spindle to provide a grease seal between the spindle and the hub, with said housing and said seal totally enclosing said switch.

Claim 10

The speed sensor of claim 8 wherein said end walls of said members each have an inner peripheral edge juxtaposed in axially spaced relation with one another, and said seal comprises a resilient elastomeric band having a pair of external grooves individually frictionally receiving said inner edges of said members to thereby retain said seal oN said housing and provide a closure for the inner periphery of said housing.

Claim 11

The speed sensor of claim 8 in which said switch is pivotally mounted in said housing by a pin fixed to one of said outer walls of one of said members.

Claim 12

The speed sensor of claim 1 in which said switch comprises a commercially available miniature switch.

Claim 13

An anti-skid vehicle braking system speed sensor for a wheel mounted on a hub mounted for rotation on a spindle with the hub having a bore therein concentric with the axis of the spindle and normally used to retain a conventional grease seal comprising, a housing having a generally cylindrical side wall portion adapted to be frictionally received in said bore in said hub for rotation therewith, a centrifugally actuated switch having at least one set of contacts, said switch being mounted in said housing such that centrifugal force acting on said switch caused by a change in the rotary speed of the hub and wheel from a predetermined speed will change the electrical state of said one set of contacts, and a resilient seal carried by said housing and adapted to engage a generally circular surface of the spindle to provide a grease seal between the spindle and the hub.

Claim 14

An anti-skid vehicle braking system speed sensor for a wheel mounted on a hub mounted for rotation on a spindle with the hub having a bore therein concentric with the axis of the spindle and normally used to retain a conventional grease seal comprising, a housing having a generally cylindrical side wall portion adapted to be frictionally received in said bore in said hub for rotation therewith, a centrifugally actuated switch having at least one set of contacts, said switch being mounted in said housing such that centrifugal force acting on said switch caused by a change in the rotary speed of the hub and wheel from a predetermined speed will change the electrical state of said one set of contacts, and a resilient seal carried by said housing and adapted to engage a generally circular surface of the spindle to provide a grease seal between the spindle and the hub.

Claim 15

The speed sensor of claim 12 in which said switch comprises a commercially available miniature switch.

Claim 16

The speed sensor of claim 12 wherein said housing and said resilient seal totally enclose said switch.

Claim 17

The speed sensor of claim 12 which also comprises a ring of an electrically conductive material mounted externally on said housing and adapted to encircle and be generally coaxial with the spindle, said ring of an electrically conductive material being electrically connected with one of said contacts of said switch.

Claim 18

The speed sensor of claim 12 in which said housing comprises first and second circular members having generally axially extending cylindrical side walls adapted for telescoping engagement with each other and generally radially extending end walls being axially spaced in assembly, said resilient seal being carried by said axially spaced end walls with said resilient seal and said housing totally enclosing said switch.