Patent GB-1050284-A (GB)
IPC: G05B19/04
Abstract: 1,050,284. Copy-turning. GEORG FISCHER A.G. May 14, 1964 [May 21, 1963], No. 20215/64. Divided out of 907,809. Headings B3B and B3T. A lathe or milling or other machine tool as claimed in Claim 1 of Specification 907,809 comprises manually-operated switches 121 to 126 for selecting the number of roughing cuts to be taken and the cutting-depth for each cut, automatic means for performing the cuts, for making a template-controlled finishing cut and for returning the depth determining devices to zero, and a series of adjustable switches LS-1 to LS-4, Fig. 7 (not shown), co-operating with a cam 215 on the tool slide 17 to limit the return movements of the slide after successive roughing cuts. The template 40 (or a pair of indexible templates) is mounted on a bar 37 carried between adjustable centres 38, 39. It is engaged by a follower 36 acting through a valve 33 which controls the supply of fluid from a pump 42 to each side of a piston 21 attached to the slide 17. A cylinder 24 forming the tool-slide is thus moved on the piston 21. The initial position of the tool-slide is set by a screw 31. The follower 36, carried on a pivot 35, is biased away from the template by a spring 58 acting through levers 52, 54 on a slide 30. The lever 54 can be rendered inoperative by movement of a piston 100 which moves a link 70 to compress the spring. A spring 29 then moves the valve 33 so that the tool-slide moves upwardly until the feeler contacts the template 40. The limits of movement of the slide 24 are determined by stops 67, 80 which are adjusted by wheels 83, 84 and screws 81, 85. The stop 80 thus controls the maximum depth of cut, and can be set automatically by a motor 90 rotating a shaft 93 carrying a cam 97 to operate a counting device 98. One revolution of the cam is equivalent to a tool advance of 0À04 inch. The shaft 93 also carries a clutch 95 and a brake 96. When the tool-slide 24 is retracted, a dog 113 swings a bell-crank 113<SP>1</SP> to move a valve 107, Fig. 8 (not shown), and operate a clutch 220 in a gear and worm drive 228, 229 to a pinion 18<SP>1</SP> engaging a rack 20 to return the slide 17. On the return, a stop 105 moves the valve 107 to neutral position to stop the slide 17 and a dog 108 engages a switch 109 to energize a solenoid 103 to move the rod 70 to cause advance of the tool. A dog 114 then engages a rod 212 and rocks a lever 211 to move the clutch valve 107 from its neutral position to cause advance movement of the slide 17. If a selector 160, Fig. 3 (not shown), is set to "Manual", the clutch 220 can be controlled by a lever 230. The stop 80 is set against a scale to determine the depth of the first cut. The manual selector switches 121-126, Fig. 4 (not shown), are therefore set to determine the depths of the 2nd-6th cuts and the number of cuts. A stepping switch 150, Fig. 3A (not shown), adds up the cutting depths so that, when cutting is complete, the tool can be returned to its initial position. In operation, the main motor is started by a push-button and the headstock spindle is clutched thereto. The selector 160 is set to " Automatic ", and a cycle start push-button 161 is depressed. Thereby, the rod 70 is moved to release the lever 52, and the slide 24 moves in until the lever 52 abuts the stop 80. A roughing cut ensues until the tracer 36 abuts a shoulder 115 on the template 40. The template 40, Fig. 1a (not shown), is in an electrical circuit and is mounted in an insulated sheath 117, the circuit being completed when the tracer contacts it, causing the slide 24 to be withdrawn as determined by the stop 67. The dog 114 then trips the rod 212 and the slide 17 is returned at fast speed. The arm 151 of the selector switch 150 and the arm 141 of a selector switch 140 are advanced until the arm 141 engages the contact 175 selected by the switch 121, which has been selected by a stepping switch 130. The motor 90 thereby advances the stop 80 three increments and is then braked. When the rod 107 abuts the dog 105, the tool-slide is again fed in, the slide 17 is moved at feed-speed and the stepping switch 140 is returned to zero. Cuts are made in succession until an arm 132 of the stepping switch 130 reaches a contact selected by the "number-of-cuts" selector switch 126 and causes the slide to be returned and the electrical circuit of the template to be rendered inoperative. When the slide 14 is again advanced, therefore, the tracer contacts the template 40, the stop 80 being advanced clear of the arm 52 by allowing the selectorswitch arm 141 to advance to a contact 178. The finishing cut is thus controlled hydraulically by the template, When a " short-traverse cycle " switch 217 is moved to " On ", a selector 200, advanced with the switch 130, brings selectors 206-210 into circuit successively. Each selector is initially set to determine the operative sequence of the switches LS-1 to LS-5. These switches and selectors are used to limit one traverse of the tool to the length of the left portion of the work illustrated in Fig. 5 (not shown), then two traverses to the length of the central of the portions to be machined, and finally to one traverse of the right portion. The switches LS-1 etc. cause movement of a piston 204<SP>1</SP> which pushes the reversing valve 107 to a neutral position before a dog 204 actuates the switch 205 to advance the tool again by operating the piston 100 and the rod 70. When the template-controlled cut has subsequently been completed, the dog 110 strikes the switch 111 to reverse the traverse of the slide 17 until the dog 215 engages the switch LS-1 and the machine is ready for a new cycle. During a cycle, all the parts may be returned to their initial positions by a "Cycle-stop" button 159.