摘要 |
The apply and release hydraulic parking valve (20, 120) comprises a housing (40, 140) having therein a bore (42) with first (52, 152) and second (54, 154) reservoir grooves communicating with one or more reservoir ports (46, 146A, 146B), a supply groove (63) communicating with a supply port (47, 147), and apply (44, 144) and release ports (48, 148) communicating with said bore (42, 142). A spool valve (60, 160) is located slidably within the bore (42), the spool valve (60, 160) activated by a lever (31, 131) received within an opening (67, 167) of the spool valve (60, 160). One end of the spool valve (60, 160) has a pair of washers (74, 76) disposed thereabout with a spring member (80, 180) located about the spool valve (60, 160) and between the washers (74, 76), and a stop sleeve (82, 182) located about the spool valve (160, 60). The spool valve (60, 160) includes a chamfered groove (61) engaging a check valve (50, 150) within the supply port (47, 147). Displacement of the lever (31, 131) effects axial displacement of the spool valve (60, 160) which opens the check valve (50, 55) to permit hydraulic fluid pressure to be communicated to the bore (42) and with the apply and release ports (44, 144, 48, 148) corresponding to the direction of axial displacement of the spool valve (60, 160).
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