Abstract: Single and dual brake feel augmentation valves for use in a vehicle skid control system are disclosed. The brake feel augmentation valve has a first port which receives hydraulic fluid from a constant source, a second port which receives hydraulic fluid from a pilot operated pressure metering valve, a third port which supplies hydraulic fluid to the brakes, and a hydraulic return port. A pressure balancing spool valve, with a brake pressure feedback channel, controls the supply of hydraulic fluid to the brake pressure port from the constant source port as a function of the metered pressure and fedback brake pressure. When the metered pressure is greater than the fedback brake pressure, the spool valve allows hydraulic fluid from the constant source to flow into the brake pressure port, thereby filling the brakes.

Abstract: An improved modulator for an anti-skid brake control system generates a modulated brake control signal as a time integral function of the difference between an input signal indicative of a braking condition and a variable threshold signal. The preferred embodiment includes a computer which stores a number of rate values. An appropriate one of these values is selected depending on the magnitude of the difference between the input signal and the threshold signal. This rate value is then added to the previous modulated brake control signal to generate an updated modulated brake control signal. Both symmetrical and asymmetrical sets of rate values are disclosed.

Abstract: An initialization apparatus for an antiskid brake control system including a modulator which generates a brake control signal as a time integral function of an error signal operates to initialize the modulator to a preselected value of the brake control signal when excessive braking action is sensed after a period of antiskid inactivity. The initialization apparatus also operates to initialize a reference signal in the direction of more aggressive braking and to bias the reference signal and a wheel signal toward more aggressive braking for a selected time period following initialization of the modulator.

Abstract: An antiskid braking system includes an improved apparatus for generating a lead signal to provide lead compensation. According to one feature of this apparatus, the gain of the apparatus is made to vary as a function of a signal, such as the brake control signal generated by the antiskid system, which is indicative of the coefficient of braking under severe braking conditions. Another feature of the invention is that the apparatus operates to reduce the magnitude of the lead signal when it exceeds a limit value, preferably by clamping the lead signal to a maximum magnitude.

Abstract: An antiskid braking system includes an improved lead apparatus for generating a lead signal to provide lead compensation. According to this invention, the gain of the apparatus is made to vary as a function of a signal, such as the brake control signal generated by the antiskid system, which is indicative of the coefficient of braking under severe braking conditions. Preferably the gain of the lead apparatus is varied independently of the gains of other elements of the antiskid system, such as the modulator, for example.

Abstract: An improved modulator for an anti-skid brake control system generates a modulated brake control signal as a time integral function of the difference between an input signal indicative of a braking condition and a variable threshold signal. The preferred embodiment includes a computer which stores a number of rate values. An appropriate one of these values is selected depending on the magnitude of the difference between the input signal and the threshold signal. This rate value is then added to the previous modulated brake control signal to generate an updated modulated brake control signal.

Abstract: An initialization apparatus for an antiskid brake control system including a modulator which generates a brake control signal as a time integral function of an error signal operates to initialize the modulator to a preselected value of the brake control signal when excessive braking action is sensed after a period of antiskid inactivity. The initialization apparatus also operates to initialize a reference signal in the direction of more aggressive braking and to bias the reference signal toward more aggressive braking for a selected time period following initialization of the modulator.

Abstract: A slurry electrowinning apparatus includes a tank (10) in which are mounted alternating, spaced-apart anode (18) and cathode (20) electrodes. An inlet opening (60) is formed in a side of the tank (10) for introducing a copper-bearing electrolyte to the tank (10). An overflow opening (76) is also formed in a side of the tank (10) such that a solution level (62) is maintained in the tank (10) which is above the inlet opening (60). Baffles (64) are mounted within the tank (10) for evenly distributing the slurry within the tank (10) between the anodes (18) and cathodes (20). Both the anodes (18) and the cathodes (20) are supported within the tank (10) by electrode guides (22) such that a high pressure contact between the electrodes (18, 20) and the main electrical bussing (78) is provided.

Abstract: A vehicle skid control system including a wheel speed transducer, skid control circuitry responsive to the transducer for generating a control current output and a skid control valve responsive to the control current for providing single-gain control in a skid control mode under normal operating conditions. The skid control valve includes a first stage for generating a control pressure from a source of substantially constant fluid pressure which is normally controlled exclusively by the current output of the valve driver, which control pressure is representative of the threshhold pressure which an input metered pressure should not exceed if a skid condition is to be avoided. The control valve further includes a second stage pressure balancing system responsive to allow a metered supply pressure to be applied to a brake port as long as the metered pressure does not exceed the first stage control pressure.

Abstract: A method and apparatus for measuring a predetermined relatively small volume of liquid from a supply liquid and subsequently dispensing that volume of liquid. A long hollow tube having one end sealed is connected at the other end to an open-ended probe. The long tube is curved into at least one C-shaped segment and is generally rigid along its entire curved length. With the probe tip inserted into the supply liquid, the curved tube is flexed about an axis normal to the plane in which it lies, thereby decreasing the cross-sectional area of the tube. Since the tube is generally rigid along its entire curved length, this flexure of the tube increases the internal volume of the tube thereby reducing the pressure within the tube and withdrawing liquid from the supply liquid into the probe. The amount of liquid withdrawn into the probe is determined by the amount of flexure of the tube.

Abstract: A vehicle skid control system including a wheel speed transducer, skid control circuitry responsive to the transducer for generating a control current output and a skid control valve responsive to the control current for providing single-gain control in a skid control mode. The skid control valve includes a first stage for generating a control pressure which is controlled exclusively by the current output of the valve driver, which control pressure is representative of the threshold pressure which an input metered pressure should not exceed if a skid condition is to be avoided. The control valve further includes a second stage pressure balancing system responsive to the pressure for allowing the metered supply pressure to be applied to a brake port as long as the metered pressure does not exceed the first stage control pressure.

Abstract: A vehicle skid control system including a wheel speed transducer, skid control circuitry responsive to the transducer for generating a control current output and a skid control valve responsive to the control current for providing single-gain control in a skid control mode. The skid control valve includes a first stage for generating a control pressure which is controlled exclusively by the current output of the valve driver, which control pressure is representative of the threshold pressure which an input metered pressure should not exceed if a skid condition is to be avoided. The control valve further includes a second stage pressure balancing system responsive to the pressure for allowing the metered supply pressure to be applied to a brake port as long as the metered pressure does not exceed the first stage control pressure.

Abstract: A selective deceleration brake control system which enables the operator of an aircraft or other vehicle to preselect a rate of deceleration for the vehicle. The system produces a velocity reference signal which decreases in value at a rate indicative of the rate of vehicle deceleration selected by the operator. A signal indicative of actual wheel velocity is continuously produced and compared with the velocity reference signal to generate an error signal. The error signal is processed and used to produce a brake control signal. The system continuously controls braking effort to cause the vehicle to decelerate at the rate selected by the operator. The selective deceleration circuit cooperates with an anti-skid brake control circuit such that at any instant the circuit providing the higher brake release command will control.

Abstract: An anti-skid braking system for an automobile including apparatus for sensing rotational wheel speed, reference comparison apparatus for developing a signal indicating excessive rotational deceleration incident to incipient or actual skidding of the wheel for effecting brake relaxation and reference control apparatus for controlling the reapplication of braking effort.

Abstract: A self powered missile is provided with pairs of slotted lugs and curved nching rail cooperating with said lugs. The rail is surmounted by attachment means for fastening to a variety of launch platforms. When the missile is launched, the rail stays with the launcher platform and the lugs retract flush with the skin of the missile.