Anticreep brake system for a wheeled vehicle

Claim 2

An anticreep brake system for a wheeled vehicle having fluid pressure operated wheel brakes and a driver operated wheel brake actuator, a hydraulic connection between said actuator and said wheel brakes, a pressure trapping valve in said connection adapted to retain fluid pressure in said wheel brakes, a pressure trapping valve operator, a speed detector circuit electrically connected to said operator, said speed detector circuit forming a connection between a voltage source and said operator and including a switching circuit means for establishing and disestablishing an electrical connection between said source and said operator, a speed sensor means connected drivably to one of said vehicle wheels for developing electrical voltage pulses, a pulse storage capacitor circuit connected to the output side of said speed sensor means and the input side of said switching circuit means, and another switching circuit means for alternately connecting and disconnecting said capacitor to ground in response to the application thereto of said pulse, the input side of said other switching circuit means being connected to voltage source whereby said capacitor is charged and discharged with a frequency that is related to the speed of the vehicle wheels, the magnitude of the charge on said capacitor circuit increasing upon a decrease in wheel speed, said other switching circuit means including a reference voltage source producing a bias tending to maintain said first named switching circuit means in an open circuit condition, the voltage developed in said capacitor circuit opposing said reference voltage and overcoming the reverse bias of said reference voltage when the capacitor voltage reaches a threshold value thereby actuating said first names switching circuit means and triggering the operation of said pressure trapping valve operator.

Claim 3

The combination as set forth in claim 1 including a brake memory circuit means for establishing a connection between ground and the capacitor circuit whereby the latter is discharged therethrough when said wheel brakes are deactivated, said brake memory circuit being adapted to respond to application of wheel brakes to interrupt the ground connection through said brake memory circuit for said capacitor circuit.

Claim 4

The combination as set forth in claim 2 wherein said first named switching circuit means includes a driver operated throttle switch, one side of said switch being connected to a voltage source and the other side thereof being connected to signal output stages of said first named switching circuit means whereby a reverse bias is distributed to said first named switching circuit means to prevent the development thereby of an output signal when said throttle switch is closed.

Claim 5

The combination as set forth in claim 1 wherein said first named switching circuit means includes a driver operated throttle switch, one side of said switch being connected to a voltage sOurce and the other side thereof being connected to signal output stages of said first named switching circuit means whereby a reverse bias is distributed to said first named switching circuit means to prevent the development thereby of an output signal when said throttle switch is closed.

Claim 6

An anticreep brake system for a wheeled vehicle having fluid pressure operated wheel brakes and a driver operated wheel brake actuator, a hydraulic connection between said actuator and said wheel brakes, a pressure trapping valve in said connection adapted to retain fluid pressure in said wheel brakes, a pressure trapping valve operator, a speed detector circuit electrically connected to said operator, said speed detector circuit forming a connection between a voltage source and said operator and including a switching circuit means for establishing and disestablishing an electrical connection between said source and said operator, a speed sensor means connected drivably to one of said vehicle wheels for developing electrical voltage pulses, a pulse storage capacitor circuit connected to the output side of said speed sensor means and the input side of said switching circuit means, and another switching circuit means for alternately connecting and disconnecting said capacitor to ground in response to the application thereto of said pulses, the input side of said other switching circuit means being connected to a voltage source whereby said capacitor is charged and discharged with a frequency that is related to the speed of the vehicle wheels, the magnitude of the charge on said capacitor circuit increasing upon a decrease in wheel speed, said capacitor circuit comprising a pair of capacitors situated in parallel relationship and forming a connection between the input side of said first named switching circuit means and ground, the ground connection for one of said capacitors including an electronic switching circuit means adapted to open and close in response to the establishment and disestablishment of a signal for said pressure trapping valve operator, said electronic switching circuit means being connected to the output side of said other switching circuit means.

Claim 7

An anticreep brake system for a wheeled vehicle having fluid pressure operated wheel brakes and a driver operated wheel brake actuator, a hydraulic connection between said actuator and said wheel brakes, a pressure trapping valve in said connection adapted to retain fluid pressure in said wheel brakes, a pressure trapping valve operator, a speed detector circuit electrically connected to said operator, said speed detector circuit forming a connection between a voltage source and said operator and including a switching circuit means for establishing and disestablishing an electrical connection between said source and said operator, a speed sensor means connected drivably to one of said vehicle wheels for developing electrical voltage pulses, a pulse storage capacitor circuit connected to the output side of said speed sensor means and the input side of said switching circuit means, and another switching circuit means for alternately connecting and disconnecting said capacitor to ground in response to the application thereto of said pulses, the input side of said other switching circuit means being connected to a voltage source whereby said capacitor is charged and discharged with a frequency that is related to the speed of the vehicle wheels, the magnitude of the charge on said capacitor circuit increasing upon a decrease in wheel speed, said capacitor circuit comprising a pair of capacitors situated in parallel relationship and forming a connection between the input side of said first named switching circuit means and ground, the ground connection for one of said capacitors including an electronic switching circuit means adapted to open and close in response to the establishment and disestablishment of a signal for said pressure trapping valve operator, said electronic switching circuit means being connected to the output side of said other switching circuit means.

Claim 8

The combination as set forth in claim 5 including a brake memory circuit means for establishing a connection between ground and the capacitor circuit whereby said capacitors are discharged therethrough when said wheel brakes are deactivated, said brake memory circuit being adapted to respond to application of wheel brakes to interrupt the ground connection through said brake member circuit for said capacitor circuit.

Claim 9

The combination as set forth in claim 6 wherein said first named switching circuit means includes a driver operated throttle switch, one side of said switch being connected to a voltage source and the other side thereof being connected to signal output stages of said first named switching circuit means whereby a reverse bias is distributed to said first named switching circuit means to prevent the development thereby of an output signal when said throttle switch is closed.

Claim 10

The combination as set forth in claim 5 wherein said first named switching circuit means includes a driver operated throttle switch, one side of said switch being connected to a voltage source and the other side thereof being connected to signal output stages of said first named switching circuit means whereby a reverse bias is distributed to said first named switching circuit means to prevent the development thereby of an output signal when said throttle switch is closed.

Claim 11

An anticreep brake system for a wheeled vehicle having fluid pressure operated wheel brakes and a driver operated wheel brake actuator, a hydraulic connection between said actuator and said wheel brakes, a pressure trapping valve in said connection adapted to retain fluid pressure in said wheel brakes, a pressure trapping valve operator, a speed detector circuit electrically connected to said operator, said speed detector circuit forming a connection between a voltage source and said operator and including a switching circuit means for establishing and disestablishing an electrical connection between said source and said operator, a speed sensor means connected drivably to one of said vehicle wheels for developing electrical voltage pulses, a pulse storage capacitor circuit connected to the output side of said speed sensor means and the input side of said switching circuit means, and another switching circuit means for alternately connecting and disconnecting said capacitor to ground in response to the application thereto of said pulses, the input side of said other switching circuit means being connected to a voltage source whereby said capacitor is charged and discharged with a frequency that is related to the speed of the vehicle wheels, the magnitude of the charge on said capacitor circuit increasing upon a decrease in wheel speed, said other switching circuit means including a reference voltage source producing a bias tending to maintain said first named switching circuit means in an open circuit condition, the voltage developed in said capacitor circuit opposing said reference voltage and overcoming the reverse bias of said reference voltage when the capacitor voltage reaches a threshold value thereby actuating said first named switching circuit means and triggering the operation of said pressure trapping valve operator, said capacitor circuit comprising a pair of capacitors situated in parallel relationship and forming a connection between the input side of said first named switching circuit means and a ground, the ground connection for one of said capacitors including an electronic switching circuit means adapted to open and close in response to the establishment and disestablishment of a signal for said pressure trapping valve operator, said electronic switching element being connected to the output side of said other switching circuit means.

Claim 12

An anticreep brake system for a wheeled vehicle having fluid pressure operated wheel brakes and a driver operated wheel brake actuator, a hydraulic connection between said actuator and said wheel brakes, a pressure trapping valve in said connection adapted to retain fluid pressure in said wheel brakes, a pressure trapping valve operator, a speed detector circuit electrically connected to said operator, said speed detector circuit forming a connection between a voltage source and said operator and including a switching circuit means for establishing and disestablishing an electrical connection between said source and said operator, a speed sensor means connected drivably to one of said vehicle wheels for developing electrical voltage pulses, a pulse storage capacitor circuit connected to the output side of said speed sensor means and the input side of said switching circuit means, and another switching circuit means for alternately connecting and disconnecting said capacitor to ground in response to the application thereto of said pulses, the input side of said other switching circuit means being connected to a voltage source whereby said capacitor is charged and discharged with a frequency that is related to the speed of the vehicle wheels, the magnitude of the charge on said capacitor circuit increasing upon a decrease in wheel speed, said other switching circuit means including a reference voltage source producing a bias tending to maintain said first named switching circuit means in an open circuit condition, the voltage developed in said capacitor circuit opposing said reference voltage and overcoming the reverse bias of said reference voltage when the capacitor voltage reaches a threshold value thereby actuating said first named switching circuit means and triggering the operation of said pressure trapping valve operator, said capacitor circuit comprising a pair of capacitors situated in parallel relationship and forming a connection between the input side of said first named switching circuit means and a ground, the ground connection for one of said capacitors including an electronic switching circuit means adapted to open and close in response to the establishment and disestablishment of a signal for said pressure trapping valve operator, said electronic switching element being connected to the output side of said other switching circuit means.

Claim 13

The combination as set forth in claim 9 including a brake memory circuit means for establishing a connection between ground and the capacitor circuit whereby the latter is discharged therethrough when said wheel brakes are deactivated, said brake memory circuit being adapted to respond to application of wheel brakes to interrupt the ground connection through said brake memory circuit for said capacitor circuit.

Claim 14

The combination as set forth in claim 10 wherein said first named switching circuit means includes a driver operated throttle switch, one side of said switch being connected to a voltage source and the other side thereof being connected to signal output stages of said first named switching circuit means whereby a reverse bias is distributed to said first named switching circuit means to prevent the development thereby of an output signal when said throttle switch is closed.

Claim 15

The combination as set forth in claim 9 wherein said first named switching circuit means includes a driver operated throttle switch, one side of said switch being connected to a voltage source and the other side thereof being connected to signal output stages of said first named switching circuit means whereby a reverse bias is distributed to said first named switching circuit means to prevent the development thereby of an output signal when said throttle switch is closed.

Claim 16

An anticreep brake system for a wheeled vehicle having fluid pressure operated wheel brakes and a driver operated wheel brake actuator, a hydraulic connection between said actuator and said wheel brakes, a pressure trapping valve in said connection adapted to retain fluid pressure in said wheel brakes, a pressure trapping valve operator, a speed detector circuit electrically connected to said operator, said speed detector circuit forming a connection between a voltage source and said operator and including a switching circuit means for establishing and disestablishing an electrical connection between said source and said operator, a speed sensor means connected drivably to one of said vehicle Wheels for developing electrical voltage pulses, a pulse storage capacitor circuit connected to the output side of said speed sensor means and the input side of said switching circuit means, and another switching circuit means for alternately connecting and disconnecting said capacitor to ground in response to the application thereto of said pulses, the input side of said other switching circuit means being connected to a voltage source whereby said capacitor is charged and discharged with a frequency that is related to the speed of the vehicle wheels, the magnitude of the charge on said capacitor circuit increasing upon a decrease in wheel speed, and a brake memory circuit means for establishing a connection between ground and the capacitor circuit whereby the latter is discharged therethrough when said wheel brakes are deactivated, said brake memory circuit being adapted to respond to application of wheel brakes to interrupt the ground connection through said brake memory circuit for said capacitor circuit.

Claim 17

An anticreep brake system for a wheeled vehicle having fluid pressure operated wheel brakes and a driver operated wheel brake actuator, a hydraulic connection between said actuator and said wheel brakes, a pressure trapping valve in said connection adapted to retain fluid pressure in said wheel brakes, a pressure trapping valve operator, a speed detector circuit electrically connected to said operator, said speed detector circuit forming a connection between a voltage source and said operator and including a switching circuit means for establishing and disestablishing an electrical connection between said source and said operator, a speed sensor means connected drivably to one of said vehicle Wheels for developing electrical voltage pulses, a pulse storage capacitor circuit connected to the output side of said speed sensor means and the input side of said switching circuit means, and another switching circuit means for alternately connecting and disconnecting said capacitor to ground in response to the application thereto of said pulses, the input side of said other switching circuit means being connected to a voltage source whereby said capacitor is charged and discharged with a frequency that is related to the speed of the vehicle wheels, the magnitude of the charge on said capacitor circuit increasing upon a decrease in wheel speed, and a brake memory circuit means for establishing a connection between ground and the capacitor circuit whereby the latter is discharged therethrough when said wheel brakes are deactivated, said brake memory circuit being adapted to respond to application of wheel brakes to interrupt the ground connection through said brake memory circuit for said capacitor circuit.

Claim 18

The combination as set forth in claim 13 wherein said first named switching circuit means includes a driver operated throttle switch, one side of said switch being connected to a voltage source and the other side thereof being connected to signal output stages of said first named switching circuit means whereby a reverse bias is distributed to said first named switching circuit means to prevent the development thereby of an output signal when said throttle switch is closed.