| 摘要 |
881,505. Lathe details. ERNAULT-BATIGNOLLEO, M. Sept. 30, 1959 [Oct. 2, 1958], No. 33170/59. Class 83 (3). The hydraulic feed system for the tool-slide 1, Fig. 2, controlled by the electromagneticallyoperated valve 12, is similar to that described in Specification 756,947. The fast approach movement of the tool-slide and slow feed under control of the rack 5 moved from the spindledriven feed-shaft 51 is obtained as described in the above Specification, a screw 10, Fig. 3, keyed to but slidable along the feed-shaft driving through a spiral wheel 9 and free-wheel 8 a pinion 6, Fig. 4, meshing with the rack 5. To obtain a dwell before reversal so that the tool may finish a face, for example, two switches 25, 26 are included in the circuit of the electromagnet 16, 17, Fig. 2. At least one switch must be closed for actuation of the magnet to place the valve 12 in position for forward feed. A stop-member 33 moves with the toolslide and opens switch 26 just prior to reaching the " dead-stop " 34. When this occurs rack 5 and adjuster 11 engage switch-arm 27 and the end of valve 12 to maintain a balance between springs 19, 29 and the electromagnet to give the controlled feed set by the spindle-drive to the rack. The rack 5 moves away from switch-arm 27 after stopping of the tool-slide and, after a predetermined number of spindle revolutions, switch 25 opens and thus cuts the circuit to the electromagnet. The valve 12 moves upwards under the pressure of spring 18 and the tool-slide returns under hydraulic pressure to its starting position. Other arrangements with a different disposition of the mechanical parts, are described. |
