US508196A

US508196A - Machine foe grinding the edges of

Info

Publication number: US508196A
Authority: US
Publication date: 1893-11-07
Anticipated expiration: 1910-11-07

Description

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4 Sheets-Sheet 1. AM.

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OLE DB EYEGLASS LENSES.

Patented Nov. 7, 1893.

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(No Model.)

. T. A. WILLSON 85H. BILGRAM.

MACHINE FOR GRINDING THELEIIJIgES OF SPEGTAULE 0R EYEGLASS No. 508,196. Patented Nov. 7, 1893.

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' 4 SheetsSheet 4. T. A. WIL'LSON 80H. BILGRAM. MACHINE FOR GRINDING THE EDGES OF SPEUTAULE OR E (No Mbdel.)

YEGLASS LENSES.

. Patented NovQ'Z, 1893.

UNITED STATES PATENT OFFICE.

THOMAS A. WILLSON, OF READING, AND HUGO BILGRAM, OF PHILADELPHIA, PENNSYLVANIA; SAID BILGRAM ASSIGNOR TO SAID W-ILLSON.

MACHINE FOR GRINDING THE EDGES OF SPECTACLE OR EYEGLASS LENSES.

SPECIFICATION forming part of Letters Patent No. 508,196, dated November 7, 1893. Application filed August 4. 1892. Serial No. 442,127. (No model.)

To aZZ whom it may concern.-

Be it known that we, THOMAS A. WILLSON, residing in the city of Reading, county of Berks, and State of Pennsylvania, and HUGO BILGRAM, residing in the city and county of Philadelphia and State aforesaid, bothcitizens of theUnited States of America, have invented certain new and useful Improvements in Machines for Grinding the Edges of Spectacle and Eyeglass Lenses, of which the following is a specification, reference being had therein to the accompanying drawings.

Our invention relates to the construction of a machinefor grinding the edges of spectacle and eye-glass lenses to adaptvthem to the frames therefor, and it consists in a construction by which the elliptical'motion of the glass is made absolute and with the minimum of friction; the lensis centered with certainty on its holders, and in its proper elliptical position and in the case of concaveconvex or coquille lenses the beveled edge follows the double curve due to theconversion of the circle into an ellipse; the grinding wheels are given a movement radial to the center of the lens, whereby the projecting corners are first roughly ground off and the grinding is then continued to the proper size of the lens and also a movement tan: gential to the lens for the purpose ofgrinding both sides of the beveled edge equally. 7

Referring to the accompanying drawings, Figure 1 is an elevation of the machine, partly in section. Fig. 2 is an elevation, partly in section, proximately at right angles tojthe' Fig. 3 is a plan of position shown in Fig. 1.

the machine. Fig. 4 is a section of the base of the machine on a broken line through the centers of the operative shafts. Fig. 5 is a section of the carriage supported by the arbor and carrying the grinding-wheel slide. 6 and 7 are, respectively, plan and section, and elevation of the gage-chuck centering the lens-blank on the spindle. v Figs.8 and 9 are, respectively, plan and section of the half.

bell on the rod carrying the upper lens-holder whereby that holder is centered on the lens. Fig. 10 is a. gear-wheel driving the spindle carrying the lens. Figs. 11 and 12 are guide- Fig plates carried in this gear-wheel to allow the elliptical movement of the spindle.

This machine consists essentially of an elliptical lathe, having at its head a cup carryin g a leather disk, between which and a springpressed holder, free to move with the ellipticity of the lathe, and also carrying a leather disk, a lens-blank is centrally clamped with ment tangential t0 the lens, and thus grind the edge of the lens evenly on both sides, and wear themselves evenly.

A. is the frame of the machine.

B. is a vertical spindle placed within an cecentric sleeve 0. which revolves at twice the velocity of the spindle, by which the motion of an elliptic lathe is given to the spindle. This spindle is provided at its upper end with a cup D. which carries a disk of leather and supports the lens E. The lens is held in place by another disk of leather carried in the cup-shaped appendage F. at the extremity of the rod G., which has ball-joints at both ends and is held down in bearing by a spring H. compressed by the screw 1., as a result of which the lens is held firmly in position and given an elliptical motion. The lens-blank E. must be centered on the spindle B. in such position that its longer axis will coincide with the longer axis of the ellipse produced by the movement of that spindle. For this purpose we place on the spindle B. the gage-chuck J., held from turning on the spindle bya feather but capable of vertical movement upon it. This gage-chuck is shown in detail in Figs. 6 and 7. It has a number of radial grooves, the bases of which are on the line of the ellipse of the lens, in which grooves are. pins K. held inward by elastic bands. When the lens-blank is to be placed in position the gagechuck is raised till the pins are in the plane of the blank, (as shown in Fig. 2,) which is then inserted between them. If the blank happens to have ragged points, from imperfect cutting, the pins in contact with these points will recede without putting the lens out of center.

Upon the rod G. is a bell-shaped device L. shown in detailin Figs. 8 and 9, half of which is cut away, which is movable vertically upon the rod, and which, when down, partly incloses the gage-chuck J. and centers the cup F. over the lens E. as shown also in Fig. 2. Then in this position the screw I. is turned down, bringing pressure upon the rod G.; the gage-chuck is lowered and the cup is raised, as shown in Fig. 1 and the lens is ready to be ground, and when ground will be of the proper elliptical form, being so moved by the lathe. In the case of concavo-convex or coquille lenses, one of which is represented in Fig. 1, it is necessary that the cut edge shall be on a curve, and, to that end, that the spindle carrying the lens shall have a reciprocating vertical movement in relation to the grinding wheels as well as a movement producing an ellipse. To obtain this movement the lower end of'the spindle B. is provided with a ball working in a socket-step M. resting on an inclined plane N. shown in Figs. 1 and 4. The center of the spindle B. having a circular movement, from the action of the eccentric sleeve 0., the socket-step will rise and fall, once for each revolution of the sleeve, and twice for each revolution of the spindle. These vertically oscillating devices as dc scribed are only used in the case of coquille lenses, and not when grinding plain lenses, when the spindle is furnished with a plain step.

The part of the apparatus above described is driven by the pulley 0., the shaft of which is geared to the spindle and sleeve. By the gearing shown in Figs. 1 ands the motion of the pulley O. is transmitted to the spindle B.

and sleeve 0. so that the sleeve is driven at twice the velocity of the spindle. This results in a movement of the spindle eccentric to the wheel which drives it. For the purpose of accommodating the parts to this movement the devices are inserted which are'shown in detail in Figs. 10, 11, 12, in which P. is the wheel rotating the spindle, having a large central opening and two downwardly-projecting lugs Q. Q., which fit into the upper slots of the ring R., in the lower slots of which is fitted the bar 5., Fig. 12, upon which is the socket T., which carries the spindle B. In

order to enable the adjustment of the spindle B., and thereby the gage-chuck J. to its proper elliptical position the socket T. is split and thus rendered elastic, producing a friction coupling.

U. is an arbor carrying the carriage V., in which is the slide V. supporting the journals W. W., driven by belting, and carrying the juxtaposed grinding wheels X. X which grind the edge of the lens on both sides. Besides their rotary movement these wheels have a triple movement; a vertical movement,

and movements both proximately radial and tangential to the lens. The vertical movement is given by means of the nut Y. and is for the purpose of adjusting the grinding wheels so that the edge of the lens shall be equally beveled.

the rotation of the carriage V. on the arbor U., and automatically by the rotation of the arbor obtained by gearing shown in Figs. 2 and 4, the arbor being connected to the carriage by a friction coupling consisting of setscrews Z. Z. under which are leather washers, shown in Fig. 5. By means of this friction coupling the wheels are moved out of contact with the lens by the handle (a) for the purpose of removing the ground lens and inserting a new blank, and are then brought back to their grinding position. If not quite so returned they are still farther moved by the rotation of the arbor U. till the motion of the carriage is arrested at the proper position by the stop (Z2).

ThetangentialinovementoftheslideV.carrying the gri'nding-wheel-jou rnals is produced by a forked bracket (0) upon the slide V which bracket engages with an eccentric ((1) connected to the arbor U. by the friction coupling (2). By means of this eccentric and forked bracket the grinding wheels are moved tangentially on the edge of the lens, with the result of an even bevel on the lens and an even wear on the grinding wheels. For the purpose of putting the wheels in proper position to begin grinding on the lens-blank they are so moved by the handle (f) on the eccentric (01), this movement bring enabled by thefriction coupling (e).

We claim as our invention- 1. A machine for grinding the edges of spectacle and eyeglass lenses having rotatable elliptically-inovin g holders for the glass, devices holder in the elliptical axis of its movement, and to center the clamp upon the blank, two grinding wheels juxtaposed adapted to grind the two.sides of the edge of the lens at the desired bevel, devices adapted to give to the grinding wheels a motion tangential to the lens while it is being ground, devices adapted to eitect a vertical adjustment of the grind ing wheels, devices adapted to impart to the lens holder a reciprocating motion in the direction of its axis of rotation.

2. A machine for grinding the edges of spectacle and eyeglass lenses having rotatable elliptically moving holders for the glass, and de vices adapted to center the lens-blank on the lens holder in the elliptical axis of its movement.

3. A machine for grinding the edges of spectacle and eyeglass lenses having rotatable elliptically moving holders for the glass and devices adapted to impart to the lens-holder a reciprocating motion in the direction of its axis of rotation in relation to the grinding wheels.

adapted to center the lens-blank on the lens- The radial movement is given manually by "tacle and eyeglass lenses having rotatableel liptically moving holders for the glass, devices adapted to center the lens-blank on the lensholder in the elliptical axis of its, movement and to center the clamp upon the blank, and devices adapted to impart to thejlens-holder a reciprocating movement in the direction of its axis of rotation in relation to the grinding wheels.

5. In a machine for grinding the edges of spectacle and eye-glass lenses the combina;

tion of a spindle having themotion ofan elliptic lathe, as B., having at its top aholder for a lens, and a gage-chuck, as E., held from turning on the spindle but capable of a vertical. movement upon it and having elastically attached pins forming an ellipsewhoseaxis is in the axis of the elliptical movement of the spindle.

6.7In a machine for grinding the edges of spectacle and eye-glass lenses the combination of a spindle having the motion of an elliptic lathe, as B., having at its top a holder for .a le I1S and ;a spring-pressed-rod, as.G., havingat its upper end a fixed. support and at its lower end aclamp adapted tobear upon the lens, and having ball-joints at both ends,

whereby the clamp is adapted to follow the.

elliptical movement of the lens and to remain in bearing upon it.

7. The combination-of the sleeve C..1nount-.

, ed in a frame, the spindle 'B, eccentrically 8. Thecombination ofisleeveOl mounted in a frame, spindle B. eccentrically placed therein, devices adapted, to cause the sleeve to re- .volve at twice the velocity of the spindle, a

ball-bearing at the. foot of spindle B., and devices adapted to cause said ball-bearing to .rise and fall at each revolution of the sleeve.

- devices adapted to cause the sleeve to revolve at twice the velocity of the spindle consisting in part of a gear-wheel adapted to rotate the spindle, a universal sliding joint substantially as specified, adapted to accommodate the rotary motion of said gear-wheel to the eccentric motion of said spindle.

10. The combination of a sleeve, as 0., a spindle, as B, eccentrically placed therein, devices adapted to cause the sleeve to revolve at twicet-he velocity of .the spindle consisting in part of a gear-wheel adapted to rotate the spindle, a universal sliding joint substantially as specified, adapted to accommodate the rotary motion of said gear-wheel to the eccentric. motion ofsaid spindle, said devices comprising a connection between said gear-wheel and said spindle adapted to allow the adjustment of the spindle to a predetermined axis of ellipticity. 11. The combination of an ellipticlathe, devices for holding a lens-blank thereon, an elliptic gage-chuck adapted to center the lensblank in its proper elliptic position and devices adapted to enable the adjustment ofthe longaxis, of said gage-chuck to the long axis of the ellipse produced by the movement of said lathe.

THOMASA. WILLSON. HUGO BILGRAM.

Witnesses:

. ALF.v H. FABER, H. D. DUNN.