| 摘要 |
<p>1,014,908. Hydraulic securing mechanism. DEERE & CO. Sept. 12, 1963 [Sept. 28, 1962], No. 35976/63. Heading B8B. [Also in Divisions E1 and F1] An earth working tool (Fig. 1, not shown) is carried by a boom 20 (Fig. 2), rotatable relative to a fixed frame 37, 38, 40 by a device which automatically brakes the rotary movement towards the ends of the range of rotation. A shaft 80 and caps 55, 56 (Fig. 3) are rigidly attached to structure 40, while a barrel 63 comprising members 61, 62, 64, which carries the boom 20 and its actuating cylinder 24 on brackets 70, 71 (Fig. 2), is rotatable on bearings 59, 60. An annular chamber (Fig. 4) enclosed between barrel 63 and shaft 80 is divided into two by a vane 85 attached to shaft 80 and a vane 95 attached to barrel 63. The boom 20 is rotated by directing fluid from control valves, not shown, into one of inlets 100, 101 causing the barrel 63 and vane 95 to move relatively to vane 85 and fixed shaft 80. Fluid in advance of vane 95 is discharged through one of outlets 106, 107 built into the bottom wall 62 of barrel 63 and communicating with the chamber by apertures 108, 109. As the barrel 63 rotates these apertures are successively covered by vane 85, reducing the fluid flow rate and thus progressively braking the movement of the barrel and the boom 20. Figs. 5 . . . 8 (not shown) illustrate how inlets 100, 101 and outlets 106, 107 are connected in pairs, each inlet having a one-way poppet valve. In an alternative embodiment the boom is mounted on shaft 80 and barrel 63 is attached to the fixed frame.</p> |
