Patent GB-762966-A (GB)
Title: An improved feeler control for copying machines
IPC: B23Q35/32
Filed: 1953-12-01
Abstract: 762,966. Copy milling ; copy - planing. SCHMID, W. K. Dec. 1, 1953 [Dec. 1, 1952], No. 33388/53. Class 83 (3). [Also in Group XXXVIII] A copying machine for enabling either a punch or a die to be cut from a single template comprises a main feeler and attached auxiliary feeler which follow the contour of the template by electric or hydraulic means, the auxiliary feeler being free to rotate about the main feeler axis, thereby locating the two feelers so that a line through their axes is always normal to the edge of the template and causing a cutting tool to be similarly always normal to the surface as it cuts a work. The machine frame 35, Fig. 5, supports a table 15 movable horizontally by a motor acting through a reversible magnetic clutch 16, and mounting two coupled tables 14, 19, rotatable by a motor acting through a reversible magnetic-clutch 17, table 14 carrying a template 40, and table 19 the work 41. A cutting tool 27, attached to a toothed segment 29, Fig. 4, movable in a slot in an arcuate guide 30 and rotatable about its cutting point by a motor 34 acting through reversible magnetic clutch 33, is mounted on the frame 35. The tool is an end-mill when the internal surface of a die is being produced, and a shaping-cutter when a punch 41 is being cut. In the latter case, the tool holder 45 is reciprocated on guides 50 by mechanism 54. The tool holder 45 is rotatable in trunnions 46, 47 attached to bearing blocks 48, 49 to enable a hollow groove to be made at the foot of the punch. A feeler mechanism 42, comprising a shaft 1, Fig. 3, carrying a main feeler 5 and an auxiliary feeler 6 adjustable in a bracket 2 which is itself rotatable on shaft 1, is assembled on the frame 35 with the auxiliary feeler 6 against the edge of the template 40. The feeler-shaft 1 is associated with a group of switches, actuated by deflection of the shaft from the vertical, to produce selective energization of clutches 16, 17, causing the table 15 and tables 14, 19 to move so that the tool 27 follows the auxiliary feeler 6 as it scans the template 40, as described in Specification 759,700, [Group XXXVIII]. The relative positions of the feelers 5, 6 is such that a line through their axes is always normal to the surface of the template. When there is relative movement between the two feelers to maintain this condition, a sliding contact 22 on the bracket 2 moves over a group of contacts on a member 23, causing selective energization of clutch 33, whereby the tool 27 is also rotated by the same amount to maintain it normal to the work surface. The contact 22 is loosely supported by a part 55 on the bracket 2, and maintained central by springs 56, 57. Movement of the bracket 2 forces contact 22 to touch followup switch-contact 58 or 60, depending on the direction of movement, thereby operating relay R<SP>1</SP> or R<SP>2</SP> to energize coil 62 or 63 of the magnetic clutch 33 so that motor 34, acting through bevel gears 64-66 and friction disc 67 or 69, drives the shaft 68 to rotate an additional contact 22a associated with circularly spaced segmental contacts I<SP>1</SP>-VIII<SP>1</SP>, each connected to similar contacts I-VIII associated with contact 22, whereby as lever 22a goes beyond the angularly-displaced position of lever 22, a holding circuit for the relay R<SP>1</SP> or R<SP>2</SP> through the segmental contacts is broken, winding 63 or 64 is de-energized, and the shaft 68 comes to rest.