599,500. Dressing grinding - wheels. TIMKEN ROLLER BEARING CO. Nov. 15, 1945, No. 30554. Convention date. Feb. 19. [Class 60] A grinding-machine has means for dressing the grinding wheel face comprising a slide carrying the grinding wheel for moving said wheel towards and away from the work, a traversing slide for moving the dressing tool across the face of the grinding wheel, a transverse slide movable towards and away from the grinding wheel and carrying the traversing slide and tool, a fluid-pressure cylinder and piston device operatively connected to the traversing slide, a control valve in a fluid-pressure system which valve is opened by sliding movement of the grinding wheel slide away from the work to enable fluid pressure to enter the said fluid-pressure cylinder and operate the traversing slide, means controlled by said wheel slide for releasing the fluid pressure in the cylinder, means for returning the traversing slide, and feed mea.ns mechanically operated by the return movement of the traversing slide whereby the slide carrying the said traversing slide is fed a predetermined distance towards the grinding wheel after each complete reciprocation of said traversing slide. Mounted on a wheel slide 4, which. carries a grinding wheel 1 to be dressed and is slidable on a fixed base to and from the work, is a raised plate 9, Fig. 4. This plated 9 supports a feed-up slide 10 which has adjustably bolted on its face a guide plate 15, swivel mounted at 16, slidable transversely on which is a traversing slide 11 movable in one direction by a fluid operated piston 27, Fig. 6, and in the opposite direction by a spring 28. The slide 11 carries in turn a slide 12 carrying a diamond 25. Bolted to the rear of the slide 12 is a template 32 which co-operates with a roller 35 journalled on a bolt adjustably fixed to the guide plate 15 so that, as the slide 11 is traversed, the slide 12 moves relatively and at right angles thereto against the action of a spring 40 thus causing the diamond 25 to dress the face 34a of the wheel 1, Fig. 24. The feed-up slide 10 is given an intermittent feed by a screw 43 which is automatically rotated after each wheel dressing operation by a ratchet 44 operated by a spring held pawl actuated by movement of the slide 11 relative to the slide 10 ; the screw 43 may be rotated by hand. The slide 11, normally held in one extreme position by the spring 28 is actuated by fluid pressure means, mounted on the body 6 of the machine, automatically operated by movement of the wheel slide 4 from the work. A swinging cam 67, Fig. 11, held by a latch 79 is carried by the slide 4 and as said slide 4 is moved from the work the cam depresses a roller 78 on a lever 74 to open a self-closing valve 63 in an air supply line 64 thus admitting pressure air to a cylinder 65 to raise a piston 92, Fig. 21, slidable therein against a spring 93 ; this operates a pawl 101, Fig. 11, to move a ratchet wheel 100 (not shown) and thus a notched cam wheel 108 contacting a roller 113 on a lever 114. According to the number of teeth in the ratchet wheel, the number of notches in the cam and the length of the piston stroke, so the number of withdrawals of the slide 4 is varied before a notch engages the roller 113 to set off a train of operations to actuate the dressing tool. When a notch engages the roller 113 the lever 114 is lifted and a master slide valve 115 is pressed upwardly by a spring 115a, Fig. 21, thus allowing pressure air to flow from a chamber 120 below the piston 92, through a passageway 119 and a pipe 123 to an air cylinder 124 where it moves a common piston 131, Fig. 23, upwardly in an oil cylinder 130 to force oil through a flexible conduit 30 to a hydraulic cylinder 26 operating the slide 11. As the piston 131 moves upwardly a trip rod 134, adjustable in length corresponding to the desired stroke of the slide 11, moves with it to disengage the latch 79 from the cam 67 and thus collapse said cam to permit the valve 63 to close and open the conduit 64 to the atmosphere ; the pistons 92 and 131 and the slide piston 27 are thus all moved back by their respective springs and the dressing cycle is completed. Arrangements are provided for allowing operation of the mechanism when the master valve 115 is depressed by manuallyoperating a valve 128 (not shown). For dressing a wheel 1a, Fig. 25, with a bevelled face a rocker 148 engages a cant 146 as before, the rocker stop screws 151, 153 respectively engaging the moving slide 11 according to the direction of movement of the cam 146, so that the diamond 25 moves in contact with the face of the grinding wheel from the sharp corner A to the blunt corner and out of contact with the wheel during the return stroke.