GB1311851A - Machines for smoothing an polishing lens - Google Patents

Abstract

1311851 Grinding lenses E M CROCKFORD 27 July 1970 [30 April 1969] 21978/69 Heading B3D A lens smoothing and polishing machine comprises a work-holder 6 for a lens 5, a tool holder 12 for a tool 13, means 75 for holding the tool in engagement with the lens, and means for driving the holders to produce relative motion thereto of which one holder has circular translatory motion about a first axis which has orbital motion about a second axis, the driving means also being coupled to the other holder to impart eccentric motion to the other holder about the second axis, and the coupling including means for adjusting its eccentricity relative to the second axis. As described, the lens 5 is carried by a holder mounted by a ball joint 7, or tapered spigot 10 on the upper end of a wobble bar 3 which is non-rotatably supported in a sleeve 23 mounted on the pivots 24 of a gimbal mounting 25. The lower end of the bar 3 has a sliding connection 26, with a rod 27 having a ball 28 received in a block 29 carried by a disc 43 having a slotted adjustment 44, 45 with a lower disc 42 whereby the radius of the block 29 relative to disc 42, and hence the inclination of the bar, is adjusted. The disc 42 is secured to a gear 41 which is rotatably mounted coaxial with a pulley 36 and connected by planet gears 38, 39 rotatably mounted on the pulley to a fixed gear 37. The pulley is driven by a belt 35 from a shaft 30 connected by gearing 31, 32 to an electric motor 33. The tool 13 is carried by a holder 12 and between the faces of the tool and workpiece is a porous sheet 14 which is impregnated with abrasive slurry supplied from the outlet 15 of a pump 16 which is driven by shaft 30 and connected by drain pipe 18 to a collecting tank 20, a bellows 22 sealing the gimbal mounting from the contents of the tank. The holder has a ball connection 48 with a driving pin 70 eccentrically adjustable on a spindle 56 but is held against rotation about its own axis but permitted to effect a circular translatory movement by a peg connection with a block 46 supported by a linkage 49, 52 from a bracket 54 on the frame of the machine. The spindle 56 has a splined connection 64 with a pulley 63 belt driven from the motor 33 and is located in the eccentric bore of a sleeve 57 having a pulley 60 driven by a belt 61 from the shaft 30. The spindle, at its upper end, has a pin and groove connection 72 with a linkage 74 operable by a pneumatic motor 75 to raise and lower the tool and adjust the pressure applied by the tool to the workpieces. The tool is thus driven with a circular translatory motion about the axis of the spindle 56 which is moved in a circular path by rotation of the sleeve 57. The workpiece is rotated and moved in an orbital path of a radius determined by the relative adjustment of the discs 42, 43. The tool and workpiece may be reversible, and the workpiece may be convex or concave.