Antiskid brake system for vehicles

Claim 2

In a vehicle brake system having a master cylinder, a storage reservoir connected to the master cylinder and at least one wheel brake assembly having a wheel cylinder normally connected to the master cylinder for actuating the brake, an antiskid system comprising; a pressure reservoir, means for maintaining the pressure reservoir at a pressure higher than the pressure in the master cylinder, and a pair of valves, one of the pair of valves normally connecting the wheel cylinder to a master cylinder, both of the pair of valves being directly connected together to cooperate in connecting the wheel cylinder to the storage reservoir to reduce brake pressure upon actuating of the one of the pairs of valves by a first signal indicating in incipient locking of the wheel and both of the pair of valves being directly connected together to cooperate in connecting the wheel cylinder to the pressure reservoir to restore the brake pressure upon actuation of the other of the pair of valves by a second signal independent of the first signal, the second signal indicating that danger of immediate wheel locking has been avoided.

Claim 3

The antiskid system of claim 1 wherein; the first and second signals are rotary wheel threshold deceleration and acceleration signals.

Claim 4

The antiskid system defined in claim 1 wherein; the means for maintaining the pressure reservoir at a pressure higher than the pressure in the master cylinder are an automatic pump and a check valve connected between the master cylinder and the pressure reservoir.

Claim 5

The antiskid system of claim 1 wherein; the pair of valves comprise a first and second electromagnetic valve, each of the first and second valves including an inlet and first and second outlets, the first valve by means of the inlet and the first outlet thereof normally connecting the wheel cylinder to the master cylinder and in the excited position by means of the inlet and the second outlet of the first valve connecting the wheel cylinder to the inlet of the second valve, the second valve by means of the inlet and the first outlet thereof normally connecting the second outlet of the first valve to the storage reservoir and in the excited position by means of the inlet and the second outlet of the second valve connecting the second outlet of the first valve to the pressure reservoir, the first valve being excited in response to the first signal and at least the second valve being excited in response to the second signal.

Claim 6

The antiskid system defined in claim 4 wherein; the means for maintaining the pressure reservoir at a pressure higher than the pressure in the master cylinder are an automatic pump and a check valve connected between the master cylinder and the pressure reservoir.

Claim 7

The antiskid system defined in claim 4 including a throttle arranged between the pressure reservoir and the second valve.

Claim 8

The antiskid system of claim 4 wherein; the first signal is an electrical signal generated by a deceleration contact in response to a wheel deceleration which exceeds a predetermined threshold and the second signal is an electrical signal generateD by an acceleration contact in response to a wheel acceleration which exceeds a predetermined threshold.

Claim 9

The antiskid system defined in claim 7 wherein, the means for maintaining the pressure reservoir at a pressure higher than the pressure in the master cylinder are an automatic pump and a check valve connected between the master cylinder and the pressure reservoir.

Claim 10

The antiskid system defined in claim 7 including means for holding the first valve in the excited position until the pressure from the master cylinder is relieved whereby the wheel cylinder will alternately be connected to the storage reservoir and the pressure reservoir.

Claim 11

The antiskid system of claim 9 wherein; the means for holding the first valve in the excited position comprise a holding element having an input connected to the output of the deceleration contact and an output connected to the first electromagnetic valve, an OR element having a first input connected to the output of the deceleration contact and a second input connected to the output of the acceleration contact, an AND element having a first input connected to the output of the holding element and a second input connected to the output of the OR element and a flip-flop having an input connected to the output of the AND element and an output connected to the second electromagnetic valve.

Claim 12

The antiskid system defined in claim 10 including a throttle disposed between the pressure reservoir and the second valve.

Claim 13

The antiskid system defined in claim 10 including a pressure-regulating valve disposed between the pressure reservoir and the second outlet of the second valve.

Claim 14

The antiskid system defined in claim 4 wherein both the first and second valves are excited by the second signal.

Claim 15

An antiskid system defined in claim 4 including a pressure-regulating valve disposed between the pressure reservoir and the second outlet of the second valve.

Claim 16

In a vehicle brake system having a master cylinder, a storage reservoir connected to the master cylinder and at least one wheel brake assembly having a wheel cylinder normally connected to the master cylinder actuating the brake, an antiskid system comprising a pressure reservoir, means for maintaining the pressure reservoir at a pressure higher than the pressure in the master cylinder, and valve means for connecting the wheel cylinder to the storage reservoir to reduce brake pressure in response to a signal indicating an incipient locking of the wheel and for connecting the wheel cylinder to the pressure reservoir to restore the brake pressure in response to a signal indicating that danger of immediate wheel locking has been avoided; the valve means comprising a first and second electromagnetic valve, the first valve normally connecting the wheel cylinder to the master cylinder and in the excited position connecting the wheel cylinder to the inlet of the second valve, the second valve normally connecting the outlet of the first valve to the storage reservoir and in the excited position connecting the outlet of the first valve to the pressure reservoir, the first valve being excited in response to the signal indicating an incipient wheel lock and at least the second valve being excited in response to a signal indicating the danger of wheel lock has been avoided; the signal indicating incipient wheel lock being an electrical signal generated by a deceleration contact in response to a wheel deceleration which exceeds a predetermined threshold and the signal indicating that the danger of wheel lock has been avoided being an electrical signal generated by an acceleration contact in response to a wheel acceleration which exceeds a predetermined threshold; further including means for holding the first valve in the excited position until the pressure from the master cylinder is relieved whereby the wheel cylinder will alternately be connected to the storage reservoir and the pressure reservoir; and the means for holding the first valve in the excited position compriseS a holding element having an input connected to the output of the deceleration contact and an output connected to the first electromagnetic valve, an OR element having a first input connected to the output of the deceleration contact and a second input connected to the output of the acceleration contact, and AND element having a first input connected to the output of the holding element and a second input connected to the output of the OR element and a flip-flop having an input connected to the output of the AND element and an output connected to the second electromagnetic valve.

Claim 17

In a vehicle brake system having a master cylinder, a storage reservoir connected to the master cylinder and at least one wheel brake assembly having a wheel cylinder normally connected to the master cylinder actuating the brake, an antiskid system comprising a pressure reservoir, means for maintaining the pressure reservoir at a pressure higher than the pressure in the master cylinder, and valve means for connecting the wheel cylinder to the storage reservoir to reduce brake pressure in response to a signal indicating an incipient locking of the wheel and for connecting the wheel cylinder to the pressure reservoir to restore the brake pressure in response to a signal indicating that danger of immediate wheel locking has been avoided; the valve means comprising a first and second electromagnetic valve, the first valve normally connecting the wheel cylinder to the master cylinder and in the excited position connecting the wheel cylinder to the inlet of the second valve, the second valve normally connecting the outlet of the first valve to the storage reservoir and in the excited position connecting the outlet of the first valve to the pressure reservoir, the first valve being excited in response to the signal indicating an incipient wheel lock and at least the second valve being excited in response to a signal indicating the danger of wheel lock has been avoided; the signal indicating incipient wheel lock being an electrical signal generated by a deceleration contact in response to a wheel deceleration which exceeds a predetermined threshold and the signal indicating that the danger of wheel lock has been avoided being an electrical signal generated by an acceleration contact in response to a wheel acceleration which exceeds a predetermined threshold; further including means for holding the first valve in the excited position until the pressure from the master cylinder is relieved whereby the wheel cylinder will alternately be connected to the storage reservoir and the pressure reservoir; and the means for holding the first valve in the excited position compriseS a holding element having an input connected to the output of the deceleration contact and an output connected to the first electromagnetic valve, an OR element having a first input connected to the output of the deceleration contact and a second input connected to the output of the acceleration contact, and AND element having a first input connected to the output of the holding element and a second input connected to the output of the OR element and a flip-flop having an input connected to the output of the AND element and an output connected to the second electromagnetic valve.

Claim 18

The antiskid system defined in claim 15 including a throttle arranged between the pressure reservoir and the second valve.

Claim 19

The antiskid system defined in claim 15 including a pressure-regulating valve disposed between the pressure reservoir and the second valve.