| 摘要 |
1527015 Earth-moving; bowl type scrapers CATERPILLAR TRACTOR CO 22 June 1976 [31 Oct 1975] 25890/76 Heading E1F A control system for the hydraulically powered loading auger of an earth-moving, bowl type scraper that has an hydraulic cushion hitch 32 which is locked out when the scraper is loading. A multi position, manually controlled pilot selector valve 25 which is used to lock out the cushion hitch also initiates operation of the auger. The control system includes a pilot operated, normally open auger control valve 31 through which flow of a signal line 39 for a normally open unloading relief valve 30 goes to drain. Moving the pilot selector valve 25 from a first to a second position pressurises a pilot line 43 to close the auger control valve 31 and thus isolate the signal line 39 from drain, closing the unloading relief valve 30 to isolate a pump 26, 28 for the auger motor 23 from drain and cause it to power the motor 23. U.K. Specification 25891176 and U.S. Specifications 3311389, 3618984 and 3469861 are referred to. |
