GB615745A - Wheel-dressing mechanism - Google Patents

Abstract

615,745. Dressing grinding-wheels. HERBERT, Ltd., A. March 5, 1946, No. 6751. Convention date, March 16, 1945. [Class 60] [Also in Group XXXVII] Dressing mechanism for an abrasive grinding- wheel having a peripheral contour includes a contoured wheel dressing roller adjustable in various ways and having means, during rotation of both the grinding-wheel and the roller to press the roller into the peripheral face of the wheel. A slide 26 is movable on a base 14 to bring a hard steel crushing roller 160 towards or away from a grinding-wheel 12. A cradle 48 is adjustable in a saddle 32 on the slide 26 to incline the axis of the roller to the same angle relatively to the grinding-wheel axis that the work is held during the grinding operation. A plate 62 is mounted, for slight pivotal adjustment about a pivot 64, on the cradle 48 and is formed at its forward end with an upwardly projecting part 86. A slide 92 carrying the crushing roller is adjustable on the part 86 so as to vary tangentially the point of contact of the roller with the grinding-wheel, this being necessary when the wheel is to grind work of a different size and thus, in the case of centreless grinders when the work contacts the wheel at a different part of the wheel circumference. The slide 26 has formed thereon two longitudinally spaced apertured lugs 170, 172, a bushing 174 being fixed in the lug 170 and an internally threaded bushing 176 keyed for longitudinal movement in the lug 172, a powerful spring 180 between the two bushings pressing a shoulder 179 on the nut 176 against the lug 172. A shaft 182 extends through the bushing 174 and is threaded to engage the lug 172. The shaft 182 is rotated relative to a sleeve 184 by a member 192 to bring the roller 160 up to the wheel, the whole mechanism is then moved a limited distance from the wheel by a handle, 212 and pinion 204 engaging rack teeth on the sleeve 184. The shaft 182 is then rotated again to move the roller forward the desired amount that it is to be fed into the wheel, and the whole mechanism then moved back, by the lever 212 moving the same distance as before, into contact with the wheel 12, the spring 180 this time being compressed when contact occurs and thereafter acting to press the roller forward the desired amount. Switches 218, 219, Fig. 2, are closed by the movement of the handle 212 so that the roller motor is energized when contact between the roller and grinding-wheel takes place, the motor being automatically stopped when the load on the roller decreases. The circuit is so arranged, Fig. 8 (not shown) (see Group XXXVII), that upon the operation of a stop switch the grinding- wheel motor is brought to a stop by reversing the current thereto, and, upon operation of the roller motor, the grinding-wheel is rotated in a reverse direction for the crushing operation. The peripheral speeds of the wheel and roller may be the same. Rollers having distorted thread profiles instead of alternating V-shaped ridges and grooves may be used. A brush 236 on the slide 92 is used for cleaning the roller.