Patent GB-493237-A (GB)
Title: Device for the dressing of single profiled screw grinding wheels
IPC: B24B53/075
Filed: 1937-11-15
Abstract: 493,237. Trueing grinding wheels. LINDNER, H., ROTZOLL, E., and MOLLER, G. Nov. 15, 1937, No. 31384. [Class 60] Means for trueing a profiled disc S for grinding rounded screw-threads comprises a crude diamond 36 for trueing the inclined flanks and the rounded edge of the disc and a rounded diamond 35 for subsequently trueing the rounded roots of the flanks. The two diamonds are carried by a tool head which can be rocked to bring either diamond into operative position, the head being carried by a support 5 rockable about a vertical axis x on a slide 2 which is adjustable on a base 1 secured on the grinding machine, the axis x passing through the centre of curvature of the rounded edge of the disc. As shown, the tool head 26 is rockable through 180‹ about a vertical axis z in an arm 24 secured to a shaft 13 journalled horizontally in the support 5. Each diamond is centrally secured in a sleeve 41 or 42 adjustably secured in the head 26, the latter being adapted to be locked in either of its limiting positions by a bolt 27. The rocking of the support 5 is limited by abutments 7 and 8 adjustable on a graduated plate 12 secured to the slide 2 to correspond to the inclination of the flanks of the disc S. The rocking of the arm 24 in the support 5 is limited by abutments 45 and 46 adjustable by micrometer screws to correspond to the length of the flanks, these abutments cooperating with abutments 49, 50 or 51, 52 on the head 26. A micrometer screw 54 carried by the support 5 is so arranged that, when in zero position, its end face 54a is at a distance from the axis z equal to the distance between the axes x and z. Each sleeve 41 or 42 is so secured in the head 26 that, when the end face 54a abuts against the corresponding diamond, the micrometer reading corresponds to the radius of curvature of the rounded edge of the disc. In operation, the crude diamond being in operative position, the support 5 is rocked to one of its limiting positions and the shaft 13 is then oscillated, by means of a hand crank 23 geared thereto, so as to true the corresponding flank. The support 5 is then oscillated, with continued oscillation of the shaft 13, to true the rounded edge, and the support is then moved to its other limiting position and the shaft oscillated to true the other flank. The tool head 26 is then adjusted to bring the rounded diamond 35 into operative position, and the rounded roots of the flanks are trued. The flanks and edge may also be finish trued. If there is any danger that the crude diamond may injure the root of the flank, the rough trueing is stopped short of the full length of the flank by adjustment of the abutments 51 and 52. The shaft 13 is longitudinally adjustable by means of a micrometer screw abutment 18. In a modification, the tool head carries the two diamonds on its end face and is secured on a horizontal shaft journalled in a slide reciprocable, between adjustable abutments, on the support 5, the shaft being adjustable longitudinally and being capable of being turned so as to bring either of the diamonds into operative position.