Wheel slip limiting apparatus with mechanical control

Claim 2

In a vehicle having an engine, a wheel driven by the engine and a non-driven wheel, the driven wheel being liable to slipping in excess of that required for maximum traction in the event excessive torque is applied thereto by the engine, apparatus for limiting excessive wheel slip of the driven wheel comprising a mechanical differential having a pair of input gears, a carrier, and a carrier mounted planet gear driven by the input gears, means for driving the input gears at speeds proportional to the speeds of the driven and non-driven wheels such that the carrier rotates at a speed proportional to the excess of driven wheel speed over the non-driven wheel speed, switch means responsive to carrier speed for periodically opening and closing when the carrier speed exceeds a minimum value corresponding to incipient excess wheel slip, and means associated with the engine and responsive to the switch means for reducing engine torque upon the occurrence of excess wheel slip.

Claim 3

In a vehicle having an engine, a wheel driven by the engine and a non-driven wheel, the driven wheel being liable to slipping in excess of that required for maximum traction in the event excessive torque is applied thereto by the engine, apparatus for limiting excess wheel slip of the driven wheel comprising a mechanical differential having a pair of input gears, a carrier, and a carrier mounted planet gear driven by the input gears, means for driving the input gears at speeds proportional to the speeds of the driven and non-driven wheels such that the carrier rotates at a speed proportionAl to the excess of driven wheel speed over the non-driven wheel speed, switch means responsive to carrier speed, the switch means being normally closed at carrier speeds below a minimum value corresponding to the onset of excess wheel slip and including means for periodically opening and closing the switch means at carrier speeds above the minimum value and for increasing the ratio of open switch time to closed switch time according to carrier speed, and means associated with the engine and responsive to the switch means for reducing the engine torque by an amount dependent upon the carrier speed.

Claim 4

In a vehicle having an engine, a wheel driven by the engine and a non-driven wheel, the driven wheel being liable to slipping in excess of that required for maximum traction in the event excessive torque is applied thereto by the engine, apparatus for limiting excess wheel slip of the driven wheel comprising a mechanical differential having a pair of input gears, a carrier, and a carrier mounted planet gear driven by the input gears, means for driving the input gears at speeds proportional to the speeds of the driven and non-driven wheels such that the carrier rotates at a speed proportionAl to the excess of driven wheel speed over the non-driven wheel speed, switch means responsive to carrier speed, the switch means being normally closed at carrier speeds below a minimum value corresponding to the onset of excess wheel slip and including means for periodically opening and closing the switch means at carrier speeds above the minimum value and for increasing the ratio of open switch time to closed switch time according to carrier speed, and means associated with the engine and responsive to the switch means for reducing the engine torque by an amount dependent upon the carrier speed.

Claim 5

In a vehicle having an engine, a wheel driven by the engine and an non-driven wheel, the driven wheel being liable to slipping in excess of that required for maximum traction in the event excessive torque is applied thereto by the engine, apparatus for limiting excess wheel slip of the driven wheel comprising a mechanical differential having a pair of input gears, a carrier, and a carrier mounted planet gear driven by the input gears, means for driving the input gears at speeds proportional to the speeds of the driven and non-driven wheels such that the carrier rotates at a speed proportional to the excess of driven wheel speed over the non-driven wheel speed, a variable duty cycle switch responsive to carrier speed and activated at a minimum carrier speed corresponding to the onset of excess wheel slip, including means for varying the duty cycle of the switch with changes of carrier speed above the minimum speed, and means associated with the engine and responsive to the variable duty cycle switch for reducing the engine torque according to the amount of excess wheel slip.

Claim 6

In a vehicle having an engine, a wheel driven by the engine and an non-driven wheel, the driven wheel being liable to slipping in excess of that required for maximum traction in the event excessive torque is applied thereto by the engine, apparatus for limiting excess wheel slip of the driven wheel comprising a mechanical differential having a pair of input gears, a carrier, and a carrier mounted planet gear driven by the input gears, means for driving the input gears at speeds proportional to the speeds of the driven and non-driven wheels such that the carrier rotates at a speed proportional to the excess of driven wheel speed over the non-driven wheel speed, a variable duty cycle switch responsive to carrier speed and activated at a minimum carrier speed corresponding to the onset of excess wheel slip, including means for varying the duty cycle of the switch with changes of carrier speed above the minimum speed, and means associated with the engine and responsive to the variable duty cycle switch for reducing the engine torque according to the amount of excess wheel slip.

Claim 7

In a vehicle having an engine, a wheel driven by the engine and a non-driven wheel, the driven wheel being liable to slipping in excess of that required for maximum traction in the event excessive torque is applied thereto by the engine, apparatus for limiting excess wheel slip of the driven wheel comprising a mechanical differential having a pair of input gears, a carrier, and a carrier mounted planet gear driven by the input gears, means for driving the input gears at speeds proportional to the speeds of the driven and non-driven wheels such that the carrier rotates at a speed proportional to the excess of driven wheel speed over the non-driven wheel speed, a centrifugal switch including a first contact element mounted on the carrier for rotation therewith and for radial movement of the first contact element, centrifugally operated means for controlling radial movement of the first contact element according to carrier speed, and a second contact element mounted in the plane of movement of the first contact element for contact thereby during carrier rotation, the second contact element having one portion in constant contact with the first contact element when the first contact element is in a radial position corresponding to low carrier speeds and another finger-like portion integral with the one portion for intermittent contact with the first contact element when the first contact element is in a radial position corresponding to a carrier speed exceeding a minimum value corresponding to the onset of excess wheel slip, and means associated with the engine and responsive to the centrifugal switch for reducing the engine torque during periods of excess wheel slip.

Claim 8

In a vehicle having an engine, a wheel driven by the engine and a non-driven wheel, the driven wheel being liable to slipping in excess of that required for maximum traction in the event excessive torque is applied thereto by the engine, apparatus for limiting excess wheel slip of the driven wheel comprising a mechanical differential having a pair of input gears, a carrier, and a carrier mounted planet gear driven by the input gears, means for driving the input gears at speeds proportional to the speeds of the driven and non-driven wheels such that the carrier rotates at a speed proportional to the excess of driven wheel speed over the non-driven wheel speed, a centrifugal switch including a first contact element mounted on the carrier for rotation therewith and for radial movement of the first contact element, centrifugally operated means for controlling radial movement of the first contact element according to carrier speed, and a second contact element mounted in the plane of movement of the first contact element for contact thereby during carrier rotation, the second contact element having one portion in constant contact with the first contact element when the first contact element is in a radial position corresponding to low carrier speeds and another finger-like portion integral with the one portion for intermittent contact with the first contact element when the first contact element is in a radial position corresponding to a carrier speed exceeding a minimum value corresponding to the onset of excess wheel slip, and means associated with the engine and responsive to the centrifugal switch for reducing the engine torque during periods of excess wheel slip.

Claim 9

In a vehicle having an engine, a wheel driven by the engine and a non-driven wheel, the driven wheel being liable to slipping in excess of that required for maximum traction in the event excessive torque is applied thereto by the engine, apparatus for limiting excess wheel slip of the driven wheel comprising a mechanical differential having a pair of input gears, a carrier, and a carrier mounted planet gear driven by the input gears, means for driving the input gears at speeds proportional to the speeds of the driven and non-driven wheels such that the carrier rotates at a speed proportional to the excess of driven wheel speEd over the non-driven wheel speed, a variable duty cycle switch comprising a pair of contact elements, one contact element being mounted on one of the input gears for rotation therewith and including a circular portion concentric with the axis of rotation of the one input gear and at least one finger portion extending outwardly from the circular portion, the other contact element being mounted on the carrier for movement therewith and spring-biased toward the axis of rotation for contact with the circular portion to provide an uninterrupted contact between the contact elements, centrifugal force producing means subject to carrier rotation for moving the other contact element radially outwardly against the spring bias into contact with the finger portion to provide interrupted contact between the contact elements when the carrier speed exceeds a minimum value corresponding to the onset of excess wheel slip, wherein the finger portion is shaped to diminish the period of contact between the contact elements as the carrier speed increases, and means associated with the engine and responsive to the variable duty cycle switch for reducing the engine torque according to the amount of excess wheel slip.

Claim 10

In a vehicle having an engine, a wheel driven by the engine and a non-driven wheel, the driven wheel being liable to slipping in excess of that required for maximum traction in the event excessive torque is applied thereto by the engine, apparatus for limiting excess wheel slip of the driven wheel comprising a mechanical differential having a pair of input gears, a carrier, and a carrier mounted planet gear driven by the input gears, means for driving the input gears at speeds proportional to the speeds of the driven and non-driven wheels such that the carrier rotates at a speed proportional to the excess of driven wheel speEd over the non-driven wheel speed, a variable duty cycle switch comprising a pair of contact elements, one contact element being mounted on one of the input gears for rotation therewith and including a circular portion concentric with the axis of rotation of the one input gear and at least one finger portion extending outwardly from the circular portion, the other contact element being mounted on the carrier for movement therewith and spring-biased toward the axis of rotation for contact with the circular portion to provide an uninterrupted contact between the contact elements, centrifugal force producing means subject to carrier rotation for moving the other contact element radially outwardly against the spring bias into contact with the finger portion to provide interrupted contact between the contact elements when the carrier speed exceeds a minimum value corresponding to the onset of excess wheel slip, wherein the finger portion is shaped to diminish the period of contact between the contact elements as the carrier speed increases, and means associated with the engine and responsive to the variable duty cycle switch for reducing the engine torque according to the amount of excess wheel slip.