Patent GB-205132-A (GB)
Title: Improvements in or relating to profiling tools
IPC: B23B29/28
Filed: 1922-06-06
Abstract: 205,132. Burnett, A. S., Collins, T., and Shaw & Co., Ltd., F. June 6, 1922. Lathes.-In a profiling machine the tool or work is traversed positively along two paths in conformity with a profile gauge by means which are simultaneously controlled by electrically actuated elements, the circuits of which are completed and broken by means of a single tracer contacting with the gauge. As applied to a lathe, the feed screw 5 for imparting longitudinal traverse to the tool saddle and a back shaft (not shown) for imparting cross traverse are driven through shafts 7, 8, worm shafts 11, 12, and gearing. The gearing comprises shafts 21, 22 driven from the headstock, each shaft carrying pinions 17, 18, one of which is keyed to the shaft, the other being connected thereto by a hand operated clutch 25. The pinions 17, 18, drive pinions 13, 14 loose on the worm shafts, the former through reversing wheels 23 and the latter directly. Clutches 27 connect either drive to the worm shafts and are operated by T-shaped levers 44 which are rocked by means of two pairs of rapidly reciprocating toggles 36, 37. The latter are maintained in their extended condition by springs 38 and are reciprocated from a cam shaft 31, so that when stops 40, 42 intercept their motion they are raised, as shown in Fig. 2, to strike the respective arms of the levers 44. Neutralizing stops 51 are provided for maintaining the clutches in their neutral positions. The forward and reverse stops for each worm shaft are controlled by solenoids 45 - - 48 and the neutralizing stops by two solenoids 53, the circuits to which are made and broken by switches actuated from a pivoted and sliding tracer. In the diagram of connections shown in Fig. 9, the tracer 49, which follows the profile of a, gauge A, is pivoted to a block 55, itself pivoted to the tool slide 57 and adapted to bear on a lever 63. Switches 75, 78 and 79 are operated by the tracer and lever through amplifying means (not shown) which may consist of pivoted levers or a fluid pressure system &c. The tracer and lever 63 are connected through a main switch B to one of the power mains 81, 82. In operation, the cross reverse traverse is de-clutched, and a spring 80 maintains contact at 78, 67, thus energizing solenoids 45, 48, the former of which feeds the slide forward until the tracer meets the gauge at a, while the latter opens a switch 87 and keeps solenoid 47 out of action. Further motion rocks the lever 63 and breaks contact at 78, 67, which stops the lor.gitudinal feed due to 45 and closes the switch 87, energizing solenoid 47 and actuating the cross traverse till a point b is reached. When the tracer looses contact with the gauge, The longitudinal traverse again operates until the fever 63 is rocked to actuate the cross traverse, and these motions continue till the point d is reached. The longitudinal pressure on the tracer is now increased and rocks the lever 63 to close the switch 68, 79, whereupon the solenoid 46 is intermittently energized to actuate the longitudinal reverse traverse. When the point e is reached, the lateral pressure of the gauge rocks the tracer and makes contact at 75, 76 which energizes the solenoids 86, 84, the former rocking the lever 63 and maintaining contact at 68, 79, while the latter opens a switch 83 and prevents the solenoid 45 from operating. Further motion of the tracer makes contact at 77, 89, thus energizing solenoid 48 and stopping the cross traverse while the longitudinal reverse traverse continues. The solenoid 84 may be dispensed with, in which case the wire Y, Z would be removed, and additional wires x and a sliding contact at 67 would be required. When copying a contour while traversing parallel to the longitudinal axis of the machine, the operations are similar but the longitudinal reverse traverse is de-clutched. An alterative form of wiring is described. According to the Provisional Specification instead of controlling the moving parts of the machine through make and break mechanism magnetic clutches may be employed. Specification 225,598 is ' referred to.