Anti-skid control device and system

Abstract

A mechanical anti-wheel lock-up control system for avoiding wheel lock-up and consequent skidding in a motor vehicle, including a lock-up sensor or control device arranged in an open end of the axle tube and protectively covered over by the hub cap of the wheel, the control device being of an inertia flywheel actuable valve type controlling relief from and application of service air to the braking mechanism, the control device having an input shaft associated with the flywheel by means of an axially disengageable cam clutch and geared to be driven by the hub cap. The control device may be employed in a system individual to each wheel, or in a system serving a plurality or pair of wheels. In the latter, a control module of valves modulates the pressure of service air feeding to the braking mechanism in controlling a wheel lock-up condition.

What is claimed is: 
     
       1. A motor vehicle including an axle tube having a wheel hub mounted thereon for relative rotation and having an open end; a hub cap covering over the open end of the axle tube and secured to the wheel hub for rotation with the latter, the hub cap defining an interior chamber adjacent the open end of the axle tube; an anti-wheel lock-up control device disposed in part in the open end of the axle tube and projecting in part into the chamber provided by the hub cap; retaining means detachably coupling the control device to the axle tube, the control device having an input drive shaft; means drivingly engaging the hub cap with the input drive shaft; a wheel mounted upon the wheel hub; a source of service air; a brake valve selectively operable for feeding the service air to a main line; a brake actuator having a pressure pilot chamber subject to reception of service air for applying braking torque to the wheel; a service air relay having an inlet connection with the main line, an outlet connection with the pilot chamber of the brake actuator, and a vent to atmosphere; a pressure air operable pilot valve in the relay normally communicating the inlet and outlet and blocking the outlet from the vent; the control device having a supply inlet connected to a branch of the main line, an air signal outlet connected for conducting an air signal to presurize the pilot valve in the relay, and a signal vent to atmosphere; a control valve in the control device shiftable from a normal position communicating the signal outlet to the signal vent to a reserve position sealing the signal vent and communicating the supply inlet with the signal outlet, and inertia flywheel means in the control device having response to rapid decelerating and accelerating actions of the wheel controlling shifting of the control valve. 
     
     
       2. A motor vehicle as in claim 1, wherein a second anti-wheel lock-up control device is similarly associated with the opposite end of the axle tube and the related hub cap. 
     
     
       3. A motor vehicle as in claim 1, wherein the control device includes a peripheral flange disposed in abutting relation to the end of the axle tube, and the retaining means is a collar nut collaring the flange and threadedly engaging the axle tube. 
     
     
       4. A motor vehicle as in claim 1, including air operable brake actuating means for braking rotation of the wheel hub, an air operable relay having a connection with an air service line for conducting operating air to the brake actuating means, and valve means in the control device having response to rapid deceleration of the wheel hub to interrupt feeding of operating air by the relay to the brake actuating means. 
     
     
       5. A motor vehicle as in claim 1, wherein planetary gearing drivingly engages the input shaft, and means drivingly engages the hub cap with the gearing. 
     
     
       6. A motor vehicle as in claim 3, wherein the hub cap has a plurality of internal longitudinally extending slots and planetary gearing has a drive cage formed with lugs slidably received into the slots. 
     
     
       7. A motor vehicle as in claim 1, including brake actuating means for applying braking torque to the wheel hub, service air brake valve means selectively operable to feed service operating air to the brake actuating means; and means in the control device having response to rapid deceleration of the input shaft to interrupt feed of service operating air to the brake actuating means, and having response to predetermined reacceleration of the input drive shaft to restore feed of service operating air to the brake actuating means. 
     
     
       8. A motor vehicle as in claim 7, including a control module valve means connected between the control device and the brake actuating means for throttling and as a consequence limiting service air pressure to the brake actuating means. 
     
     
       9. An anti-wheel lock-up control unit for use in combination with a vehicle having an axle tube open in an end thereof, a wheel hub rotatably supported upon the axle tubes, and a hub cap removably attachable to the hub in axial extension thereof for providing an interior chamber adjacent the open end of the axle tube, the control unit comprising a housing having a reduced forward section adapted to be slidably entered into the open end of the axle tube and having an enlarged rear section adapted to project from the axle tube for reception into the chamber of the hub cap, a clamping collar supported upon the housing for detachably clamping the control unit in position to the axle tube, an input shaft rotatably supported in the housing, and drive means supported upon the shaft including a driven member having lugs adapted for obtaining an axially slidable splined driven connection with the interior of the hub cap for transmitting rotation of the hub through the hub cap to the shaft, the control unit after having been combined with the axle tube and hub cap being slidably removable as a unit from the axle tube following removal of the hub cap and the collar. 
     
     
       10. An anti-wheel lock-up control unit as in claim 9, wherein the drive member has rotation relative to the shaft and drivingly engages planetary gearing having a sun gear keyed to the shaft whereby rotation of the drive member is transmitted to the shaft. 
     
     
       11. An anti-wheel lock-up control unit as in claim 10, wherein a flywheel has a bearing support upon the shaft for relative rotation and relative axial movement, and a cam toothed disengagable clutch engages the flywheel with the shaft for rotation with the shaft in an engaged conditon of the clutch, and slide valve means controlling communication of an air inlet port with an outlet port is operatively connected with the flywheel. 
     
     
       12. An anti-wheel lock-up control unit as in claim 11, wherein the clutch includes a driving member pinned to the shaft, and a driven member unitary with the flywheel, the driving member having cam teeth engaging complementary teeth of the driven member. 
     
     
       13. An anti-wheel lock-up control unit as in claim 12, wherein the driven clutch member is responsive to sudden deceleration of the driving clutch member to be cammed axially out of engagement from the driving member and to carry the flywheel with it. 
     
     
       14. An anti-skid wheel lock-up control unit as in claim 13, wherein spring means normally biases the driven clutch member axially into engagement with driving clutch member. 
     
     
       15. An anti-wheel lock-up control unit as in claim 14, wherein the spring means also biases the valve means axially into constant abutting relation with the flywheel. 
     
     
       16. An anti-wheel lock-up control unit as in claim 15, wherein the valve means has a normal position in the engaged condition of the clutch in which the air inlet port is blocked from the outlet port and the outlet port is connected with a vent port. 
     
     
       17. An anti-wheel lock-up control unit as in claim 16, wherein the valve means has an axially shifted position in a disengaged condition of the clutch in which position the valve means seals the vent port and communicates the inlet port with the outlet port. 
     
     
       18. An anti-wheel lock-up control device for controlling lock-up in a wheel of a motor vehicle having air operable braking mechanism, comprising an input drive shaft carrying a pinion adapted to have a driven connection with the wheel, flywheel means having a bearing support on the shaft for relative rotation and axial movement, axially disengageable cam toothed clutch means including a driven member carried by the flywheel means normally engaging a driving member carried by the shaft, valve means abutting the flywheel means shiftable from a normal condition blocking communication of an air service inlet with an outlet connectible to the braking mechanism to a reverse condition communicating the inlet with the outlet, and spring means constantly biasing the valve means into abutment with the flywheel means and normally maintaining the clutch means engaged, the driven clutch member being disengageable to shift the flywheel means and as a consequence the valve means axially from its normal condition to its reverse condition as a consequence of a sudden deceleration of the driving clutch member. 
     
     
       19. An anti-wheel lock-up control device for controlling lock-up in a wheel of a motor vehicle having air operable braking mechanism, comprising an input drive shaft carrying a pinion adapted to have a driven connection, flywheel means having a bearing support on the shaft for relative rotation and axial movement, axially disengageable cam toothed clutch means including a driven member carried by the flywheel means normally engaging a driving member carried by the shaft, valve means abutting the flywheel means shiftable from a normal condition blocking communication of an air service inlet with an outlet connectible to the braking mechanism to a reverse condition communicating the inlet with the outlet, and spring means constantly biasing the valve means into abutment with the flywheel means and normally maintaining the clutch means engaged, the driven clutch member being disengageable to shift the flywheel means and as a consequence valve means axially from its normal condition to its reverse condition as a consequence of a sudden deceleration of the driving clutch member. .Iadd. 
     
     
       20.  An anti-wheel lock-up control device for controlling lock-up in a wheel of a motor vehicle having a braking mechanism, comprising: an input drive shaft having a drive connection; flywheel means, supported in the control device for rotation and axial movement relative to the input drive shaft; axially disengageable cam toothed clutch means, including a driven member, carried by the flywheel means and normally engaging a driving member, carried by the input drive shaft; signal means responsive to axial movement of the flywheel means relative to the input drive shaft amd axially shiftable from a first position to a second position; and spring means constantly biasing the signal means axially towards its first position and towards the flywheel means; the driven clutch member being axially disengageable from the driving clutch member to shift the flywheel means axially and, as a result, to shift the signal means axially from its first position to its second position as a consequence of a sudden deceleration of the driving clutch member. .Iaddend. .Iadd.21. The control device of claim 20 wherein the driven clutch member is axially disengageable from the driving clutch member, so that as a consequence of a sudden deceleration of the driving clutch member, the signal means is in its second position until the speed of the flywheel means and the speed of the input drive shaft rematch. .Iaddend. .Iadd.22. The control device of claim 20 wherein the input drive shaft has a driven connection with the 
     
     
        motor vehicle wheel. .Iaddend. .Iadd.23.  The control device of claim 22 wherein the driven connection of the input driven shaft with the wheel comprises planetary gearing, mounted on the input drive shaft, having a sun gear which is keyed to the input drive shaft and idler gears which drivingly engage the sun gear and are connected to the wheel. .Iaddend. .Iadd.24. The control device of claim 23 wherein the control device is mounted in the hub cab of the wheel, the idler gears are connected to the hub cup, and a ring gear of the planetary gearing is mounted on the control device. .Iaddend. .Iadd.25. The control device of claim 24 wherein the idler gears are connected to the hub cap by means of a planetary drive cage, which is rotatably mounted on the input drive shaft, which has pins on which the idler gears are carried, and which has a peripheral lug that engages an internal slot in the hub cap. .Iaddend. .Iadd.26. The control device of claim 25 wherein the hub cap includes a plurality of internal longitudinally extending slots and the planetary drive cage includes peripheral lugs, slidably received into the slots. .Iaddend. .Iadd.27. The control device of claim 20 wherein the signal means comprise valve means that are shiftable from the first position to the second position; that in the first position, communication of an air service inlet with an air service outlet, connected to the braking mechanism, is blocked by the valve means; and that in the second position, communication of the air service inlet with the air service outlet, connected to the braking 
     
     
        mechanism, is not blocked by the valve means. .Iaddend. .Iadd.28.  The control device of claim 27 wherein, in the first position of the valve means, the air service outlet is in communication with a vent and, in the second position of the valve means, the vent is closed. .Iaddend. .Iadd.29. The control device of claim 28 wherein the braking mechanism is an air operable braking mechanism. .Iaddend. .Iadd.30. The control device of claim 20 wherein the flywheel means comprise: a slide rod, slidably positioned in an axial recess of the input drive shaft, adjacent the free end of the input drive shaft; cross pin means, carried by the slide rod, extending through the input drive shaft; and a flywheel, between the cross pin means and the driving clutch member, having a bearing support on the input drive shaft for rotation and axial movement relative to the input drive shaft. .Iaddend. .Iadd.31. The control device of claim 30 wherein the spring means bias the signal means towards the flywheel and into abutment with the slide rod, whereby the cross pin means are biased into abutment with the flywheel. .Iaddend. .Iadd.32. The control device of claim 31 wherein the spring means also bias the driven clutch member towards the driving clutch member to normally maintain the clutch means engaged. .Iaddend. .Iadd.33. The control device of claim 22 wherein the axis of the input drive shaft lies in the same direction as the axis of the axle upon which is mounted the motor vehicle wheel and the driving clutch member is positioned between the wheel and the flywheel means. 
     
     
        .Iaddend. .Iadd.34.  The control device of claim 33 wherein the axis of the input drive shaft is located along the axis of the axle upon which is mounted the motor vehicle wheel. .Iaddend. .Iadd.35. The control device of claim 34 wherein the control device is located within the axle upon which is mounted the motor vehicle wheel. .Iaddend. .Iadd.36. The control device of claim 20 wherein the spring means also bias the driven clutch member towards the driving clutch member to normally maintain the clutch means engaged. .Iaddend. .Iadd.37. The control device of claim 36 wherein the signal means are valve means that are shiftable from the first position to the second position; that in the first position, communication of an air service inlet with an air service outlet, connected to the braking mechanism, is blocked by the valve means; and that in the second position, communication of the air service inlet with the air service outlet, connected to the braking mechanism, is not blocked by the valve means. .Iaddend. .Iadd.38. The control device of claim 37 wherein, in the first position of the valve means, the air service outlet is in communication with a vent and, in the second position of the valve means, the vent is closed. .Iaddend. .Iadd.39. The control device of claim 38 wherein the braking mechanism is an air operable braking mechanism. .Iaddend.