| 摘要 |
<p>PURPOSE:To facilitate the attachment of an air cylinder to a hydraulic control valve and as well to make sure the change-over operation of the control valve, by coupling a single piston having first and second chambers defined by first and second pistons, with a spool in the hydraulic control valve. CONSTITUTION:An air cylinder 2 for urging a shift rod and a hydraulic pump 3 incorporating therein a hydraulic control valve 4 are provided in the front section of a power take-off device 1. The control valve 4 is controlled to be shifted to one of three positions by means of an air cylinder 5 coupled to a pool. An air pipe line 7 connecting between an air tank 6 and an air cylinder 5 is bifurcated in its intermediate section into two pipe lines one 8 of which is communicated with both first chamber (d) of the cylinder 5 and base chamber of the cylinder 2, and the other one 9 of which is communicated with the second chamber (e) of the cylinder 5. change-over is made between both pipe lines 8, 9 by energizing either one of solenoid valves 10, 11.</p> |
