摘要 |
A flow restriction between the control chamber of the expansion valve of the anti-skid device and the pump of the device prevents the expansion valve from moving as soon as the spool valve arrangement which opens the fail safe pressure transmission path and closes the normal path. The expansion chamber of the expansion valve is thus, in the case of pump failure, isolated from the pressure reservoir like effect of the pressure stored in the wheel cylinder(s) and the conduit between the skid device and the wheel cylinder(s) and therefore does not move as far before pressure equalization occurs across the expansion valve as in the case when a normal anti-skid operation is performed and the pressure in the wheel cylinder and the conduit is fully received in the expansion chamber. A switch incorporated in the anti-skid device is closed only when the expansion valve moves beyond the position assumed during pump failure.
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