GB574806A - Improvements in or relating to a device for facilitating precision grinding, cuttingor otherwise shaping work pieces - Google Patents

Abstract

574,806. Grinding and polishing. STEVENS, A. H. (Weldon Tool Co.). April 22, 1943, No. 6482. [Class 60] '[Also in Group XXII] In a copying machine wherein an enlarged image of the tool and work are projected on a screen so that the movements of the work relatively to the tool may be observed, the optical projecting system and the screen are attached to the work table so as to partake of all movements of the work. As applied to a grinding machine, the grinding disc 3 is carried by a horizontal spindle vertically adjusted on a pillar 2 and the work 16 is mounted on a holder 17 angularly adjustable about a horizontal axis on a slide 18 vertically adjustable by a screw and handle 22 on a slide 18a which is horizontally adjustable in one direction by a screw and handle 21 and in a perpendicular direction by a hand lever 20. The slide 18a is carried by a table 14 which may be reciprocated transversely to the cutter axis by a variable-throw crank 31 driven by a motor 30 and a link 32 attached to a fixed block 33. The table 14 is adjustably secured to a table 11 slidable on ways on a transverse carriage 6, the block 33 being adjustably secured to a rail 34 on the table 11, and the carriage being movable on ways 5 by a screw and handle 27. A handle 28 provides for adjusting -the table 11 by means of a screw, but is put out of action when the table is being reciprocated by the crank 31. A light source 36 on the table 14 illuminates the work and cutter through a condenser 46 and the shadow image thus produced is enlarged by an objective 38 on to a mirror 42 and then reflected on a translucent screen 43 such as a sheet of ground glass. The objective 38 and screen 43 are carried by a bracket 49 on the table 14 so that the entire optical system moves with the work, and a transparent plate 47 protects the condenser from cuttings. The screen 43 is arranged adjacent the control handles 26, 28 so that the operator may compare the shadow of the work with a drawing or other pattern 52 of the finished work whilst he moves the cutter vertically by the handle 26 and moves the work transversely by the handle 27, the table 14 meanwhile reciprocating continuously so as to enable the cutter to attack successive portions of a hard work-piece such as a carbide. Rotation of the work in the slide 18 enables an inclined surface thereon to be brought into a horizontal position so that it may be traversed relatively to the cutter by the handle 27, the screen 43 also being angularly adjustable in its frame 56 to bring the corresponding surface of the pattern into a horizontal position. An adjustable stop 35 is provided to engage the block 33 for positioning the table 11 and work relatively to the cutter, the cutter may be adjusted vertically by a second handle 25, and the apparatus may form a complete machine or may form an attachment to an existing machine.