| 摘要 |
<p>1509128 Reversing-gear control CATERPILLAR TRACTOR CO 10 Sept 1976 [2 Feb 1976] 37629/76 Heading F2D [Also in Division B8] A control for a winch system whose drive includes a pair of fluid pressure operated clutches 20, 25 connected alternately to drive the winch drum 47 in a respective direction and a main fluid pressure clutch 11 between the drive and the power input of the system comprises a pressure reduction valve 57 in series with a sequence valve 300 whose opening pressure level can be adjusted to a high or low valve for non- inching or inching operation of the winch. The clutches 20, 25 are normally engaged under spring bias. The control includes a manual lever 50 which is moved in slots 51-54. The lever 50 is coupled mechanically to linkages 55, 56 to the pressure reduction valve 57 and a selector valve 58. Fluid pressure is supplied from a sump 60 by a pump 61 through a pressure modulating valve 75 and the pressure reduction valve 57 in series. The lever is moved in slot 51 to select reel-in, reel-out or free operation. The position of the lever 50 in slot 51 determines the position of the selector valve 58 and hence which clutch 20, 25 is disengaged. The fluid supply to the main clutch 11 is controlled by the adjustable sequence valve 300 so that the setting of the valve determines whether the clutch is engaged during or after disengagement of one of the other clutches 20, 25. The fluid pressure is controlled by the valve 57 whose position is determined by the vertical position of the lever 50 in the slots 52-54. The sequence valve 300, Fig. 3, has a spring closed valve member 305 responsive to inlet pressure and a plunger 311 which has a stop pin 313 and a spring seat 312. The plunger 311 is rotatable to position the pin 313 in one of a pair of V-grooves 316, 317 at different distances from the valve member. The plunger 311 has a slot 318 for screwdriver adjustment.</p> |
