Patent GB-180731-A (GB)
Title: Improvements in machines for grinding the edges of spectacle glasses
IPC: B24B9/14
Filed: 1921-02-21
Abstract: 180,731. Schumann, R. Feb. 21, 1921. Lenses, grinding; driving and feed devices.-In a machine for grinding the edges of spectacle glasses, the glasses and a number of templets, corresponding in form to the most commonly used shapes of glass, are mounted to rotate in a support which is rocked about an axis parallel to the axis of the grinding-wheel; a roller abutment co-operates with the required templet and the support is reciprocated by means of a cylinder cam arranged to give an adjustable stroke to the support. A grinding- wheel 4 is journaled in a bed 1, and on ways 5 on the bed is adjustably mounted a slide 6 in which is rotatably mounted an axially slidable shaft 10. This shaft is driven, through gearing 47, 47a and a shaft 59 having therein a clutch 54, from the sliaft of the grinding- wheel. On the shaft 10 is mounted a sleeve 11 having arms 12 provided with bearings 16, 24 for shafts 17, 27 respectively. These shafts carry at their opposed ends rubber-faced discs 18, 25 for holding the glasses being ground, and on the shaft 17 are mounted templet discs 32, the various corms ot which correspond with the most commonly used shapes of spectacle glass. The shafts 17, 27 are driven at the same speed, through gearing, from the shaft 10, and, in order to move the shafts axially to grip or release the glasses, the outer ends of the shafts have arms 73, 74 resiliently mounted thereon. The outer ends of these arms carry axially aligned part; 75, 76, the opposed ends of which are screwed with righthanded and left-handed threads, respectively, to receive a correspondingly threaded union 80; rotation of the union moves the discs 18, 25 towards or from each other. The sleeve 11 carries a weight 23a which presses the glasses up to the grinding-wheel. On the slide 6 is mounted a ben-crank lever 35 carrying at its forked upper end a shaft 34, on which is slidably and rotatably mounted a flanged abutment roller 33 adapted to co-operate with any of the templets 32, the lever being adjustably fixed in position by a stud 41 and a nut 40. To hold the glasses away from the grinding-wheel, the support is rocked so that a pin 43 thereon engages with a notch in a pivoted lever 45<a>; this movement brings a cam 62 on the sleeve 11 into engagement with a lever 57, which disengages the clutch 54 and stops the rotation of the glasses. On the shaft 10 is secured a cylinder cam 13 engaging with a stud 14, which is slidably mounted in an horizontal slot 63 in a plate 15 secured to the bed 1. On the plate is mounted, by means of guidepins 101, a yoke 66 which is held down by a spring 65, Fig. 6, the position of the yoke being set by a screw 64. The yoke is wider at the top than at the bottom, the effective length of the slot 63 thus depending upon the position of the yoke. On the rotation of the cam 13 with the shaft 10, the stud 14 moves along the slot until it is arrested by the yoke; continued rotation of the cam then causes the shaft 10, and with it the glass-support, to slide axially. The reverse movement of the support takes place when the stud has reached the opposite side of the yoke. By adjustment of the yoke, the stroke of the reciprocation of the support may be adjusted according to the number of glasses being ground. In a modified construction, the stud is mounted at one end of a lever pivoted to the bed and is arrested by engagement with the sides of a V- shaped notch in an adjustable plate.