GB365563A - Improvements in or relating to grinding or abrading machines - Google Patents

Abstract

365,563. Grinding. WHITE, A. E., 5, Quality Court, Chancery Lane, London.- (Heald Machine Co. ; 10, New Bond Street, Worcester, Massachusetts, U.S.A.) Oct. 20, 1930, No. 31389. [Class 60.] Rollers, spindles, and the like, treating ; trueing rotating tools.-A machine for automatically grinding successive work-pieces to the same dimensions, for example, the inner cone member of a roller bearing, comprises means for rotating the grinding-wheels with their operative faces in a predetermined plane, and for moving a work-piece towards the wheels so that its axis is maintained at the distance from the grinding plane required to give the correct finished size to the work. The work-piece a, Fig. 12, is to be ground on the conical surface a<1> and undercut on the flange b, and is held by springs 61 on a spindle 5 mounted on a slide 3 movable up and down on the machine frame 1 by a cam 22 carried by a shaft 21 driven., through belt &c. gearing, from an electric motor 11, from which . also, through belt gearing 8, 10, 138, the spindle 5, is driven. Two grinding-wheels 25, 25a are provided driven by electric motors 26, 26a forming heads adjustable transversely by screws 29, 29a on slides 27, 27a on carriages 28, 28a slidable longitudinally on angularly adjustable bases 31, 31a. The screw 29a also is reciprocable axially by a bell crank lever 40, operated from a cam 42 on the shaft 21, in order to move the wheel 25a to prevent damage to the flange b of the work as this rises after grinding, and for removal and replacement. In order to maintain the grinding-faoes of the wheels in the predetermined planes, the wheels are trued, after a predetermined number of work-pieces have been ground, by means of diamonds 91, 91a adjustably mounted on stands 92 carried by the bases 31, 31a, the carriages 28, 28a being moved from, and back to the work for this purpose by means of pistons in fluid pressure cylinders 83, 83a. The movements of the carriages are brought about by a cam 51 on the shaft 21, which, through linkage and pawl and ratchet gearing 61, 62 rotates a cam 64 having a rise 70 operating, through a lever 72, a valve 79 controlling admission of fluid from a pump 74 to the cylinders 83, 83a ; dogs on the carriages cause the reverse movement of these, stop the motor 11 and thus movement of the slide 3, and also throttle the fluid admission to slow the carriages down as they reach the work engaging position when trueing of the wheels 25, 25a is completed. The number of work-pieces treated before the inauguration of the trueing is determined by the setting of a shaft 57 by means of an indicator 164, whereby the position of a pin 104 is adjusted, the pin 104 serving to determine, by forming a stop for a pin 103 on the ratchet 62, the rotation of the ratchet before the cam portion 70 becomes operative. The drive for the spindle 5 is from. a shaft 140 and a pulley 7 thereon, and the pulley 7 is driven from the shaft by a friction clutch, which is operated to disconnect the drive, when the slide 3 rises for removal of a work-piece, by a cam 146 on the slide and linkages 147 .. 149, a brake also being brought into operation to stop the rotation of the pulley 7 rapidly ; the clutch may be operated by a hand-lever 160. The grinding-wheels are fed forward periodically to compensate for wear and dressing by means of ratchet wheels 136, 136a on the spindles 29, 29a operated by pawls 132 actuated by cams 129 and levers 130, adjustable members 133 serving to determine the movement of the ratchet-wheels by the pawls, the cams 129 actuating the levers 130 on movement of the tables to the right.