Patent GB-190006161-A (GB)
Title: Improvements in Grinding and Finishing or Polishing Machines.
Inventor: NUTT JOSEPH NATHANIEL
Filed: 1900-04-03
Granted: 1900-06-02
Abstract: 6161. Nutt, J. N., [Johnston, A.]. April 3. Surfacing and polishing.-The blade of a table knife &c. is given a small longitudinal reciprocation and a lateral oscillation, and is pressed against a wheel with a yielding pressure in a holder which is free to follow the movements of the blade as this aligns itself with the surface of the wheel ; automatic devices for trueing the wheel and for advancing it to compensate for wear are provided. The blade of the knife bears against the vertical plate 1 of the holder, Figs. 10 and 12, and its tang is held between a spring 5 and a crosspin 6, while the groove in the bolster is engaged by a hook 9. The plate rests upon guide-pins 20 mounted in an extension 17 of the reciprocating carriage L, Fig. 4. This carriage is guided at one end in a bearing in the pan B, and at the other end it is formed with wings which are guided upon pins m fixed in studs standing upon the bottom of the pan ; it is worked to and fro by a lever o rocked by an eccentric pin on the shaft F. Through the carriage passes a spindle 26 provided at its inner end with an arm 27 which projects into the wing 2 of the holder, between a cross-bar 29 and a pin 15 having a pointed and ; when the arm is moved towards the wheel C, it pushes the holder forward, and the connection through the pointed pin allows it to assume the position required by the knife blade. For the purpose of imparting a lateral oscillation to the blade, a rod S with a bearing-ball at its upper end is mounted in a socket in the pan under the tail of the holder ; this rod receives a vertical reciprocating motion by means of a lever R and cam q<2>, which is mounted on a shaft Q, geared to the shaft F. The movement of the arm 27 is produced by a treadle 22 on a shaft 23 which, by means of a telescopic rod the parts of which are drawn together by a spring, is connected to a lever 31 on the outer end of the spindle. The movement of the treadle also, by means of the belt fork 24<a>, throws the belt F<2> on to the fast pulley f on the shaft F, and thus causes the reciprocating motion to be imparted to the carriage and the tilting movement to the holder. The parts are kept in operation for the time required to effect the grinding of one side of the knife blade by means of a rod 45 and a wheel 47 ; when the treadle is depressed, it pulls down the rod, the notched upper end of which, pressed outwards by a spring, is then locked by an annular flange on the wheel ; the wheel is, however, rotated by a pawl 47<a> and an eccentric pin on the end of the shaft Q, and, by means of projections of its flange acting upon an inclined surface on the rod, presses this back clear of the flange, thus allowing the treadle to rise under the action of a spring coiled round its shaft. The knife is then withdrawn from the wheel, and the movements of the carriage and holder cease. After a determined number of blades have been ground, the trueing-device comes into action automatically. It consists of a spindle g<2> with an arm g carrying a diamond point g<1>, which is moved across the face of the wheel by a cam-wheel I acting through a link h<1> upon a lever at the end of the spindle. The toothed periphery of the cam-wheel gears with a pinion on a countershaft driven by a belt from the boss of the loose pulley f which is constantly rotated, as the belt F<2> overlaps it even when on the fast pulley. The toothed periphery is not continuous, so that after a given movement it goes out of gear, and is held stationary by the spring brake l. To advance the wheel into gear with the pinion, the spindle 60 of the wheel 47 is fitted at its opposite end with a cam, which, after a certain rotation, liberates a slide which is shot forward by a spring and by means of a pawl in engagement with the wheel I forces it forward the required distance. The advance of the grinding-wheel to compensate for wear is produced by an adjustable eccentric on the end of the spindle 60 and a pawl in gear with a ratchet-wheel e, free to rotate but not to move axially in the bearing c of the shaft C'. This ratchet-wheel is threaded to fit over a screwed sleeve d, which forms the thrust bearing of the shaft.