Patent GB-970106-A (GB)
Title: Improvements in a machine tool
IPC: B23Q1/25
Filed: 1962-12-27
Abstract: 970,106. Change-speed and clutch control; pneumatic dashpots. CINCINNATI MILLING MACHINE CO. Dec. 27, 1962 [May 28, 1962], No. 48637/62. Headings F2D, F2L and F2S. [Also in Division B3] In a machine tool having a motor 28 driving several slides through clutch means, a brake 54 is operable under the control of a timer actuated by movement of one of the slides. The motor 28 rotates a shaft 50 either through a rapidtraverse clutch 42 and a gear 40 or a changespeed box 36 and a feed clutch 46. A milling- machine work-table 24 is moved by a screw 72 driven through reversing clutches 74 on a slide 22 moved by a screw 78 and reversing clutches 86 on a knee 16 elevated or lowered by a screw 100 and clutches 94. The clutch 74 and the brake are fluid-operated. The fluid-circuit includes valves operated by an axially and rotatably, movable post 122 having a snapaction detent and controlled by dogs 170, 172, 174, 176 and reversing valve plungers 126, 128 controlled by the dog 176. In operation, the post 122 is rotated anticlockwise manually by a lever 184 to cause a plunger 116 to move left and connect a pressure fluid supply line 140 to lines 180, 190 to engage the rapid traverse clutch 42 and the clutch 74 to rotate the table traverse screw 72. After some travel to the left, the table dog 172 engages a lug 168 on the post 122 to raise it and move a valve spool 136 down to the piston shown wherein the rapid traverse clutch line 144 is exhausted and the feed clutch line 142 connected to the line 140 to engage the feed clutch 46, the last part of the movement of the post being fluid-assisted by a piston 132 and lever 134 arrangement. Movement of the table is reversed to rapid-traverse rate when the dog 174 engages the lug 168 and moves the post 122 down. The dog 176 subsequently moves the post 122 to a neutral position and causes momentary engagement of the feed clutch to slow the drive shaft 50 prior to tripping a switch KS which respectively energizes and de-energizes solenoids 2SOL, 1SOL to move a valve spool 148 right and connect line 140 to brake line 188 to engage the brake 54. At the same time, the dog surface 176d actuates the reversing plunger 128 which supplies pressure fluid through line 194, valve 112 and throttle passage 198 to the left end of the plunger 116 which moves right to trip switch 1LS to disengage the brake 54 and to supply pressure fluid to line 192 to engage the clutch 74 for reverse rotation of the table traverse screw whereupon the table moves back at a rapid rate. At a subsequent point a dog engages the lug 166 of the post 122 and the table is stopped, the brake 54 being held on by a solenoid-operated timer for a predetermined time. Clutches 86, 94 can then be operated manually to engage feed movement to the saddle 22 or knee 16. The timer can be overridden by rotation of the post 122. The rapid traverse clutch 42 may be engaged at any time by a manually-operated valve 152 which trips switch 1PS to energize solenoid 3SOL and supply main pressure 140 to line 182. The dogs on the table may be set to traverse the table right instead of left. The post 122 may be controlled at all times by the hand-lever 184. The timer controls contacts in a box 210, Fig. 2, through a lever 214 moved by a spring 218 at a rate determined by the setting of a valve 232 allowing air to fill a chamber 220. The timer is re-set when the solenoid 216 is released and allows a spring to move the mushroom valve 224 to its upper position.