GB154577A - Improvements in machines for cutting non-circular glasses - Google Patents

Abstract

154,577. Zeiss, C., [Firm of]. Nov. 21, 1919, [Convention date]. Cutting glass.-Relates to machines, having rotary tables, for cutting non-circular glasses, particularly spectacle lenses, and consists in replacing the templet usually employed by an adjustable cutter which is given a reciprocating movement bv means of a two-armed lever having an adjustable fulcrum and rocked by an interchangeable grooved cam shaped in accordance with the curve required. By moving the fulcrum to the end of the lever, circular glasses can be cut without removing the cam member. Mounted in a sleeve f carried by a casing a is a bevel wheel d, the boss d<1> of which is connected by a pin e and a slot b<2> to a shaft b<1> so that the latter can slide in and turn with the boss d<1>. Carried by the shaft b<1> is a table b on which is supported a rubber cushion c bearing the glass z to be cut. Normally, the shaft b<1> is retained in the lowered position by a spring b<3> against which it is lifted by a hand lever g to bring the glass into contact with the cutter t. The cutter is carried by a slide s moving in a bracket m mounted on an upward extension a<2> of a laterally projecting part a<1> of the casing in which is mounted a driving bevel wheel h engaging the wheel d. Mounted on the spindle h<1> of the wheel h, and caused to rotate therewith by a spring tongue l, is an interchangeable sleeve k in which is formed a cam-groove k<1> shaped to correspond with the curve to be cut. Adapted to be reciprocated by the cam-groove is a rod p connected with the slide s by a ,screw p<3> and with the cam-groove by a lever o. the pivot pins q<1> of which move in slots a<3> in the extension a<2> and are carried by a spherical member q sliding on the lever. The pins q<1> also engage in helical grooves r<1> formed in a sleeve r surrounding the extension a<2>, the position of which thus governs the amount of movement imparted by the cam groove to the cutter t. Preliminary adjustment of the slide s and cutter t is effected through the screw p<3> by rotating a milled head p<2> carried by the rod p, rotation of the slide s being prevented by the engagement of the cutter t in a slot m<3> formed in the bracket m. Also carried by the. bracket m is a spring-depressed pin u having at its lower end a rubber ring v<1> which serves to clamp the work in position when the table b is raised. A spring-supported centring-pin b<5> is mounted in the shaft b<1>, and the operating handle i is secured to the screwed end of the spindle h<1>.