GB643240A - Improvements in forming means for grinding wheels and the like - Google Patents

Abstract

643,240. Trueing grinding - wheels. DURNDELL, G. J. Aug. 12, 1948, No. 21266. [Class 60] Forming means for grinding-wheels and the like of the kind having the tool 37, Fig. lb operated by a pantograph mechanism which causes the tool to copy on a reduced scale the movement of a tracer 59, Fig. 3, guided by the edges of a template 53, has the point of the tool and the tracer arranged to move either in a common plane or in parallel planes approximately midway between laterally-spaced pivots of a short-link connection 21 of the panto-. graph, the axes of the pivots and of the tool-holder bearings 33 being at right angles to the plane or planes. The pantograph comprises two main arms 11, 12 which are forked at one end for connection to pins 31 and 22, respectively, the pin 31 being connected by the short link 21 with two pins (not shown) co-axial with the pin 22. These pins are secured to a fixture 13, while the pin 31 is secured to the link 21. The other end of the arm 12 fixedly carries a pin 45 connected with a pin 39 by a link 42 carrying the tracer on rotatable plate 58 and a tool-position indicator 63. The latter is mounted on a rotatable shaft 65 provided with a knob 66 and a drum 67 connected with a drum on the tool-holder 34 through adjustable cables and an intermediate drum 69 mounted on the pin 39. The link 42 also supports two members 56, 57 which bear on opposite sides of a pressure plate 51 carried by an extension 48 of the fixture 13 and provided at its edges with strips 52 to limit the movement of the tracer, the boss of which may be provided with a rubber bush. The tool 37 is secured to a block 36 mounted on a slideway 38 in the tool holder 34. Preloaded ball bearings are used throughout the mechanism. The angular movement of the plate 58, Fig. 5, is restricted by a pin 61, and the tracer 59 is so arranged that its operative edge 60a, which is arcuate and concentric with the plate 58, is always presented to the template. The knob 66 may be mounted below the drum 67 and connected with it by a pinion and slidable racks, to the ends of which flexible cables from the drum are connected. The moving parts of the pantograph may be balanced by weights or springs.