Patent GB-514586-A (GB)
Title: Improvements relating to mechanism for truing grinding wheels
IPC: B24B53/08
Filed: 1938-06-01
Abstract: 514,586. Trueing grinding-wheels. JONES & LAMSON MACHINE CO. June 1, 1938. No. 16402. Convention date, Aug. 26, 1937. [Class 60] Apparatus for trueing the grinding-wheels of screw thread grinding &c. machines comprises three trueing tools, one operating-on the peri-' phery of the wheel and one on each flank of the profiled part of the wheel. The grinding- wheel 1 is mounted on a slidable frame portion 3 movable towards and from the work, and the trueing mechanism is mounted in a cylindrical casing 5'carried by the portion 3. The casing 5 is adjustable angularly in respect of an angularly fixed part 6 by means of bolt and slot connections 15, and the part 6 is slotted at 8 to engage slidably a guide bar 7 on the' portion 3. The casing 5 and .part 6 are movable to and from the wheel 1 on rollers 16, and are adjusted towards the wheel, as this wears, by mechanism including a screw 30 carrying a stop 45 engaging a rod 50 carried by the part 6 and engaging, through a ball 52, one end of a lever 54 pivoted at 55 to the part 6, and engaging with its other end, a rod 57 slidably mounted in.the casing 5. Inward movement of the casing towards the wheel 1 is produced by springs and outward movement by axial movement of the rod 57. The inner end of the casing 5 slides through a packing ring 70 in the frame 3 and has a partition 73 separating the trueing devices 80, 81, 86 from the actuating mechanism. The flank trueing devices 80, 81 are supported on rock arms 82, 83, mounted on shafts 84, 85, so that their movements to and from the wheel combined with the longitudinal movement of the casing 5 gives .the desired shape to the wheel flanks. The movement of the trueing device is obtained from an electric motor 90 mounted on the casing 5 and driving, through gearing 91-95, a shaft 96 carrying a cam 97 having therein a groove 98 engaged by a follower 99 on a rock arm 100, pivoted at 101, and provided with two gear segments 102, 103. The segment 102 engages a rack sleeve 104 on the rod 57, giving this the required axial movements, and the segment 103 engages a rack on a slide 105 guided by bars 106, 107 and carrying adjustably a cam 108 with an operative edge 109; the cam is adjustable about a pivot 110. Co-operating with the edge 109 is a follower block 115 on an arm 116 moving, through an adjustable screw 119, an arm 118, the arm 116 being freely pivoted, and the arm 118 secured to a rock shaft 84; a spring plunger 1180 holds the arms 116, 118 in contact. The shaft 84 operates the shaft 85 through arms 120, 121, a link 124 and a spring 126. The device 86 is carried by an arm 87 on a shaft 88 on which is secured an arm 133 having at one end a follower 131 engaging an edge cam 130 on the shaft 96, and rucked thereby, whilst axial movement of the device 86 is controlled by the engagement of a follower ,135 on the other end of the arm with the end face of a cam member 136, which is angularly and axially adjustable in a wall 146. The shaft 96 also may actuate various controls of the machine through switches 206-208 and collars 203, 204 on the shaft. In order to aid in setting the speed of rotation of the grinding wheel as its diameter decreases, a scale is provided indicating in connection with the fixed part of the machine the diameter of the wheel for a given position of the casing, and a table of wheel diameters and corresponding speeds, which are governed by a rheostat, is mounted on the machine. Specifications 346,743 and 486,981 are referred to.