| 摘要 |
<p>1,242,873. Shovel loaders. FORD MOTOR CO. Ltd. 15 Nov., 1968 [24 Nov., 1967], No. 54298/68. Heading E1F. The hydraulic system for the operation of a bucket loader, when the loader is mounted on the front of a tractor, has a step by step valve 36 for sequentially admitting pressurised fluid to, in accordance: with the state of the operating cycle of the loader, the appropriate one of a plurality circuits, which circuits then suitably actuate control valves 27, 29 regulating supply of pressurised fluid to piston cylinder units 16, 20 controlling the raising and tilting of the bucket of the loader to cause a desired part of the operating cycle of the loader to then be carried and completed without further control by the operator of the loader. The control circuits are such as to ensure of the bucket being maintained at a constant attitude to a datum plane during lifting of the boom of the loader, stopping of the lift of the boom on the boom reaching a predetermined height, initiating tilting of the bucket out of material to be loaded on the pressure in the piston cylinder units 16 reaching a predetermined pressure, and lifting of the boom on a torque to the driven wheels of the tractor reaching a predetermined value as the tractor with the loader thereon is advanced to drive the bucket into material to be loaded. The control of the valve 36 on the valves 37 may at any stage of the operating cycle of the loader may be overridden to allow of manual control of all or part of said cycle.</p> |
