| 摘要 |
<p>1,103,834. Copy-milling. TRUE-TRACE CORPORATION. 28 May, 1965, No.22889/65. Heading B3K. An hydraulic tracer comprises a spool valve controlled by a stylus 31 having three spherical or ball portions 32, 33, 34 by means of which it is adjustably mounted. The tracer has three valves 22, 23, 24 at right-angles to each other. The ball 32 is confined between seatings in a sleeve 50 adjustable axially by a threaded collar 58 and a sleeve 55 adjustable axially by a screw 41, the sleeves being urged apart by a spring 62. A flexible boot 64 seals the lower tracer opening. The second ball 33 is embraced by yokes connected to the valves 23, 24, one of the yokes having a gib and screw adjustment 72. The construction is similar to that described in U.S. Specification 2,753,145. The extent of angular movement of the stylus and hence the rate of movement produced in a machine by the valves 23, 24 is determined by the setting of a bevelled ring 81. The ring 81 can be axially adjusted by a lever 86 and an eccentric engaging a sleeve 87 to control the degree of engagement of the edge of the ring in a bevelled groove in a sleeve 100. The third ball 34 is recessed to accommodate a free ball 106 engaging the axially-movable spool 101 of the valve 22. Upward movement is limited by a rod 107 adjusted by a nut 111. The spool 101 is angularly adjustable to control the rate of flow. The rod 107 can be moved to one position such that upward, but not tilting, movements of the stylus cause upward movement of the spool 101 since the ball 106 rides on a plate 109: and to another position, Fig. 2, where both tilting and upward movements are effective to move the spool 101. In operation for 360 degrees copying, the seatings for the ball 32 are adjusted to prevent axial movement thereof and control is through the valves 23, 24. For co-ordinated control, the single valve 22 is used, a groove 134 being then in circuit. According to axial movements of the spool 101, so one or other of two fluid-pressure motors is supplied with pressure from a line 121 and a groove 128. At the same time, exhaust from a motor being operated is controlled or cutoff by a further portion of the spool co-operating with a groove 134. For 3-D copying using the three valves 22, 23, 24 the ball 106 contacts the plate 109, and the connections to the groove 134 are inoperative.</p> |
