Abstract:
A system for limiting the movement of a pipe (12) due to a seismic event is disclosed, including an energy absorbing device for restraining the pipe (12) in the event of the seismic event, and a clamp (19) adapted to be attached about the pipe (12) at a point where the anticipated unrestrained movement due to a seismic event is greater than the anticipated thermal novement of the pipe. The energy absorbing device (21) is connected at one of its ends to the clamp (19) and the opposite end of the energy absorbing device (21) is adapted to be connected to a substantially immovable support structure or wall (15). The device (21) includes a first elongated member (28) having a hollow portion therein and a second member (34) mounted within the hollow portion of the first member (28). One of the first and second members (28-34) has its front end fixedly connected to the clamp (19) and the other one of the members has its rear end adapted to be connected fixedly to the support structure (15). The first member (28) includes a first interference device (40, 42) so that as the first (28) and second (34) members move longitudinally relative to one another, the first and second interference devices (48, 50, 40, 42) engage one another forcibly and thereafter the first (28) and second (34) members continue relative movement for load and displacement limiting purpose until they come to rest.
Abstract:
The invention concerns a motor vehicle braking system which comprises a controllable pneumatic brake booster (2) whose control valve (19) can be actuated independently of the driver's wishes by an electromagnet (20). A control structure comprising a brake pressure regulator (8) and a control valve position regulator (18) generates signals representing the voltage to be fed to the electromagnet. In order to improve control quality, according to the invention, the brake pressure regulator (8) is formed by a parallel circuit comprising a first regulator (follower regulator (21)), which follows rapid time variations in the signal corresponding to the nominal braking pressure (Pnom), and a second regulator (target value regulator (22)) which follows slow variations or static values of the signal corresponding to the nominal braking pressure (Pnom). The output variables (Snom1, Snom2) of the two regulators (21, 22) are fed to a situation switching logic circuit (55) which switches through the output variables of the first (21) or second regulator (22) to the position regulator (18) depending on the respective selection criterion.
Abstract:
A power braking device including a pneumatic brake actuator (1) combined with a master cylinder (2) and provided with an electrically operated automatic control valve (26). Said actuator operates according to a mixed reaction principle and includes a movable pneumatic piston (5) supporting a control valve (7) actuated by a rod (8), as well as a partition (4) which is moved by a pressure differential and slidable relative to the pneumatic piston (5). Said device provides automatic braking with limited means and without disrupting the normal operation of the actuator.
Abstract:
An apparatus (10) is provided for automatically actuating a brake system (28) in a work vehicle. The work vehicle has an engine (12) and a plurality of ground engaging wheels (24). At least one of the wheels (24) is driven by the engine (12) for propelling the vehicle. The brake system (28) is provided for opposing motion of at least one of the wheels. The apparatus (10) includes speed sensor (20) for sensing actual engine speed and responsively producing an actual engine speed signal. A controller (64) receives the actual engine speed signal and produces an error signal in response to a difference between the actual and desired engine speed signals. The controller (64) further produces a control signal in response to the error signal. An actuator (76, 52, 58) is provided for receiving the control signal and controlling the braking force applied by the brake system (28) so as to reduce the error signal to zero.
Abstract:
A braking force control apparatus adapted to vary the level of a braking force generated on the basis of a brake operating condition and in accordance with a braking operation, and control a suitable braking force meeting a driver's intention. A braking force control apparatus for practicing a regular control operation in which a braking force corresponding to a brake pedal stepping force is generated, and a brake assisting control operation in which a braking force larger than that in a regular control operation is generated. In this braking force control apparatus, a stroke sensor (299) detecting a stroke amount (L) of a brake pedal (202) judges that a driver intends to discontinue a braking operation when a stroke amount (L) of a brake pedal (202) detected a predetermined period of time (TST) after a regular control operation was changed to a brake assisting control operation is not higher than a predetermined level alpha , and the brake assisting control operation is finished.
Abstract:
In a process for controlling the braking pressure depending on the rate of pedal operation, with the aid of a braking pressure sensor controlled by an outside force on exceeding an actuation threshold, during partial braking the actual values of the pedal travel (sactual) and the vehicle deceleration (aactual) or the braking pressure (pactual) are found and the actual values are compared with the reference or serial mean values. Correction factors are obtained from the difference between the actual and reference values and an adaptation factor is determined in a learning process over successive partial braking operations. The basic value of this threshold is multiplied by the adaptation factor to provide the actuation threshold.
Abstract:
A hill holder control system for a vehicle hydraulic braking system in which a valve (1) has an inlet (9) connected to a pedal-operated source of braking pressure and an outlet (10) connected to one or more brake actuators. An inclination sensitive valve member (14) is capable of closing off a valve seat (13b) to trap brake pressure in any brake actuator connected to the outlet and a command means (11, 15, 18, 19) is provided which is operated from an associated clutch pedal and which renders the valve member (14) operative to close off the valve seat when the clutch pedal is operated. The control system also includes a valve member disabling means (31) operable to unseat the valve member (14) from the valve seat (13b) to release any trapped brake pressure, and an electrical control circuit (40) including a "brakes operating" condition sensor (35), a "brakes released" condition sensor (34) and a clutch bite point condition sensor (36). The electrical control circuit (40) is arranged to operate the disabling means (31) when the three sensors (34, 35, 36) indicate the simultaneous presence of all three conditions to ensure a timed release of brake pressure on re-engagement of the clutch.
Abstract:
Proposed is a brake system for motor vehicles, with a pressure-genrating device (1) to which the individual brake cylinders (12 to 15) associated with each wheel are connected by hydraulic lines. Fitted in the hydraulic lines are actuator units (8, 9) made up of a piston/cylinder assembly (16 to 19) and an actuator (20), the actuator units making it possible to shut off the hydraulic lines. In order to convert the brake system into an active brake system, the invention proposes that, when the pressure-generating device (1) and, at least one actuator unit (8, 9) are simultaneously actuated, the force resulting from the pressure build-up in the pressure-generating device (1) and the external actuating force produced by the actuator (20) are applied jointly at the piston (22, 25) of the piston/cylinder assembly (16, 17, 18, 19).
Abstract:
This invention provides an electronic control system for automobile in which the damping force is maintained without pressing the brake pedal continuously during the automobile stops, the automobile can be started easily after the automobile is stopped on the upward slope and the alarm is generated when braking is difficult during the stop, the parking brake is operated in the braking state and the key is removed while the headlight is turned on. Furthermore, the braking force for the forward stop on the upward slope and the backward stop on the upward slope can be controlled with the inclination switches (17 and 17').
Abstract:
In order to retain a vehicle when starting uphill, vehicle speed (VREF), brake pedal actuation (BLS), starting moment (AM), state of operation of the vehicle engine (MO), actuation of a parking brake (FB) and actuation of the retaining system (EAS) are detected. When the retaining system is activated and the vehicle speed lies below a threshold value (VREF = 0), the braking power or pressure is maintained (case A) if the brake pedal is actuated and no starting moment is sensed. The braking power is increased (case B) when the driving engine is switched off (MO = 0) and neither the brake pedal (BLS = 0) nor the parking brake (FB = 0) are actuated, or when the engine is switched on (MO = 1) and neither brake pedal actuation (BLS = 0) nor starting moment (AM = 0) are detected. The braking power is reduced (case C) when the engine is switched off (MO = 0), the brake pedal is not actuated (BLS = 0) and the parking brake is applied (FB = 1) or when the engine is switched on (MO = 1) and a starting moment is sensed (AM = 1). When the vehicle speed exceeds the threshold value (VREF = 1) and/or the circuit breaker is actuated (EAS = 0), the retaining system is switched off. A warning signal (WN) may be triggered by means of a door contact (Tk) and/or seat contact (Sk).