Patent GB-270251-A (GB)
IPC: B24B9/14
Filed: 1927-01-17
Abstract: 270,251. Wernicke, O., and Muller, R., (trading as Wernicke & Co.). April 28, 1926, [Convention date]. Lenses, grinding and polishing; bevelling.-The bevelled edge of flat or convex lenses of round or oval shape are made by means cf a grinding-disc a of complementary profile to the edge desired on the lens b, the work being mounted in a swinging frame, and the grinding-wheel being tree to move axially or substantially axially so that it moves automatically when curved lenses are being ground. In one form, Fig. 3, the work frame, comprising the members e, f, g, i, is mounted to swing about the pivots i while the grinding-wheel a can slide axially in its bearings d. In a further modification, Fig. 4, the grinding-wheel may oscillate about a vertical pin n. In another modification, Fig. 7, the grinding- wheel may swing about a pivot q intersecting the grinding-wheel axis, the wheel being driven from a shaft s through a universal shaft r. Other mountings of the grinding-wheel are also described. A machine operating as shown in Fig. 7 is illustrated in Figs. 13 and 14. The grinding-wheel is driven from a pulley 56 through the ball-ended shaft r and is secured by rings 21, and screws 49, and collars 50, 51. The frame m carrying the grinding-wheel can pivot about pointed screws q mounted in a standard 57, the pivotal movement being limited by screws 35. Modifications operating in the manner diagrammatically illustrated in Figs. 3 and 4 are also described. If desired, the grinding-wheel spindle and the work-spindle may be arranged at an angle to each other. The Specification as open to inspection under Sect. 91 (3) (a) comprises also a number of modifications wherein the grinding wheel is mounted in fixed bearings and the swinging frame carrying the work is free to receive the required lateral movement. One of these modifications is illustrated in Figs. 10 (Cancelled) and 11 (Cancelled). The grinding-wheel driven by a wheel 24, is secured by flanged discs 21 and nut 22 and held axially by collars 23. The lens b is held by pads 25 between the halves of the divided spindle e both halves being driven from a driving-shaft h through spur gearing 28-30. The frame g carrying the work-spindle may oscillate about the driving-shaft h its movement being controlled by a templet 32 corresponding to the shape of the work and engaging a stop 33. The bearings of the shaft h are secured to the bedplate k which may move axially of the grinding- disc on balls 34. This movement takes place automatically during grinding according to the degree of convexity of the work, and is limited by adjusting screws 35 which may also be employed to lock the carriage against movement when flat work pieces are being ground. The machines may be made to work automatically by means of the device shown in Figs. 18 and 19. The driving-shaft h carries an eccentric i operating a ratchet wheel 60 which has a quadrantal groove 62. A lever 64 is provided with a roller 63 and at a predetermined point in the operation, the roller 63 drops into the groove 62 whereupon the end 65 of the lever engages the wheel 28 and forces the work frame away from the grinding- wheel. When this occurs a projection 66 on the swing frame engages a bevelled member 67 on a rod 68 which thereupon slides axially to disengage a clutch 72 and stop the work-spindle. The position of the groove 62 may be set by means of an index head 73. This subject-matter does not appear in the Specification as accepted.