US1742404A - Lens grinding and polishing machine - Google Patents

Description

Jan. 7, 1930. E. M, LONG 1,142,404

LENS GRINDING AND POLISHING MACHINE ITA/:s l B1/ja 1 Q n 770 /vfys Jan. 7, wao. E, M. LNG 1,742,404

LENS GRINDING AND POLISILIINGIACHIIE Filed March 12. 1925 2 Sheets-Sheet q2 l s -gma A Im( /v-roR M Emy/W /rraR :ys

Patented Jan. 7, 1930 UNITED STATES PATENT OFFICE ELI MAYNARD LONG, F GENEVA, NEW YORK, ASSIGNOR TO SHUR-ON STANDARD OPTI- CAL COMPANY, INCORPORATED, OF GENEVA, NEW YORK, A CORPORATION 0F NEW YORK LENS GRINDING ANI) POLISHING MACHINE Application filed March 12, 1925. Serial No. 14,964.

This invention relates to a -machine for grinding and polishing the surfaces of toric lenses and other objects having analogous surfaces but may be used in other relations in which an abrasive elementand a work holding element are reciprocally movable one in relation to the other within predetermined limits hereinafter defined as the field of movement of the movable element. The main object is to provide simple and efficient means for automatically changing therelative motion between the work and polishing or grinding surface at different positions during progressive grinding or polishing for the purpose of breaking up the continuity of any error or imperfection which may exist in the grinding or polishing surface. u

In other words, I have sought to produce a continuous change of the field of movement of the moving element during each cycle of reciprocal operation as the grinding or polishing progresses and thereby to reduce to a minimum the liability of scoring of the lens by slight imperfections or errors in the grinding surface.

Another object is to operate the means for changing the field of action of the movable element by a part of the same means which is employed for reciprocating said element and thereby to compound the reciprocal motions of the moving element by a single driving connection between the driving and driven elements. One of the specific objects tures of my invention.

Figure 2 is a sectional view taken in the plane of line 2 2, Figure l-looking toward the right hand butshowing the bracketvory connecting rod mainly in elevation.

-3- upon which a frame -4- is pivoted on the shaft -5-,' for vertical rocking `move-L ment. v

The front and rear ends of the frame -`4- are provided with trunnions 6- to which is pivotally connected a yoke-v-'-ffor lateral rocking movement about van axis at right angles tothe axis of the pivot v-5.--.

This yoke. -7- carries at its upper end a pivot or pivots to which is pivoted intermediate its ends an .additional frame -9- for vertical rocking movement about an axis parallel with the axis of thel pivot -5-.

which is pivoted a superposed frame -l-.llwhich extends throughv an opening -12f in the front end of the case above the lap -L--2- and carries a pin 3` adapted tov engage an underlying) lens-`holder il4, the trunvllf-aa're reci rocated forwardly and rearf axisof the pivot -e-, in al manner hereinafter described. Y

kThe extension as -11- of the frame -l-llmay be weighted or .otherwise pressed This vupper frame -9- is provided with front and rear end trunnions 10etok posts 35 is to effect a continuous variation in the amlnions 10 eing parallel with the axis of 85 plitude of reciprocation of one of the grindthe trunnions -6- and, therefore, at right ing'elements as distinguished from an interangles tothe axes of .the pivots 1 i,5- and mittent variation of amplitude. I v y Other objects and uses relating to specific The lens or lenses to be 'ground'l may be 40 parts `of the device will be brought out in fastened in any suitable manner to the under- 9p the following description. side of the lensholder-14- for reci rocal In the drawings: .movement across aiidfupon thfllppl -ace of Figure l is a transverse vertical sectional the la`p-,-2V-v forigrinding or polishing purview, partly in elevation, of a lens grinding posesas the l:frame carrying the yoke I 45 and polishing machine embodying the fea- .-7- vand -sl'il),plemental yframes -.-94- .and 95 toward the lap -2- to exert corresponding pressure upon the lens-holder -14 and thereby to hold the lens in contact with the grinding element -2-.

The parts thus far described may be of any suitable construction ca able of imparting a forward. and rearwar reciprocal motion to the lens-holder I4- and lenses carried thereby and, therefore Ido not wish to limit the invention to such construction.

The oscillatory frame or `carriage 4 is shown as provided with an upwardly projecting boss -15- having a len hwise aperture -16- in which is secure one vend of a curved arm -18- concentric with andhaving its center of curvature approximately in the axis of the `driving element presently described.

A rotary driving shaft 19+ is journaled in the upper `rear portion ofthe case -1-l transversely thereof and referably at the rear of the -supplemental ames -9- and -1Ov and is provided at one end with a reduced eccentrlc extension -20- carrying a worm -21- and. one end of a connecting rod or bracket -22- havingVA its vlowerend adapted to receive and support a laterally extending stud or bearing -23-, the intermediate portion -24- of said connecting rod being tubular for receiving a rotary shaft -25-. The shaft 19 may be driven by` any suitable means, not necessary to here illustrate or describe.

. The upper end of the bracket -22- is provided with an oil-set extension -26- havv ing a journal bearing -27- for theeccentric extension -20- to permit the latter to rotate freely therein between the hub of the worm -21- and enlarged portion of the shaft -19- which serves to old the upper end of the bracket -22- againstaxial move-V ment on the extension -20-. A

'Thelower end of the connecting rod -22 .is provided with a lateral extension -28- carryin a hub -29- in which the adjacent end vof t e stud -23- is firmly secured. The shaft -25- is journaled inthe `tubular in'- termediate portion -24- of the connecting rod -22- and has its upper end provide with a worm gear --30`- meshing with the worm -21- for receiving relatlvely slow motion therefrom.

The lower end of the shaft -25 is provided with a worm -31- meshing with a worm gear -32- which is journaled on the stud -23- and is rovided at one end with an axially extendlng eccentric cylindrical hub -33- which together with the gear -31- are rotatably mounted on the stud 23 between the hub -29- of the extension -28- and shoulder -34ron the opposite end of the stud -23- to hold the gear -32-' nd its eccentric hub 33 against axial movement on the stud.

A yoke S5-- is journaled on the eccentric .much slower rate of'spee' hub 33 of the gear S2-- and is provided with an aperture -36- for vreceiving the curved arm 18- and permitting said oke to be adjusted to different positions a ong and u on said arm, the yoke -35- being proviV ed with avset screw -37- by which 1t may be clamped to the arm -18. in any position of'adjustment'.y

.As previously stated the center of curva'- ture of the arm -18- is in 'or nearthe axis of rotation of the shaft -19- and, thereeccentric extension 2o- `or farther from the axis of the pivot -5- of the frame 4 will correspondingly increase or diminish the amount of reciprocal movement of the lens-holderacross the face of the lap.

It will be -noted,'however, that during this major reci rocal movement, the eccentric -33-#fisbe1ng continuousl' rotated at a very than that of the shaft- 191- lwhichlcauses an independent movement of the yoke 35.- and arm 1G- to which it vis secured in the direction of length of the connecting rod -22- and this inde endent movement is transmitted to the lens-bolder '-.l4-. and lens carried thereby through the mediumx of the parts 4.-', 7-, -9- and -11''.

f In other words, the yoke -35- is carried eccentrically around the axis of the stud as the latter is y reciprocated vertically by the eccentric extension 20- of the main shaft 1Q-g throughV the medium of the connecting rod 'or bracket -224- thereby causing a continually varying effective length of the connection between the driving shaft -19- and arm -18-' which in turn causes a continually changing scope and field of action ofthe lens-holder and lens carried thereby across the grinding surface of Athe lap ICS llO

iso

- rod or bracket in its extreme upper and lower positions as produced by the corresponding positions of the eccentric extension while the points 23- represent the upper and lower positions of the stud .23- as produced by the corresponding positions of` the lines 22 so that the distance between the points Q3- represent the maximum throw of the eccentric extension -20- when the yoke is in the position shown.

It will be evident however from the previous explanation that during this movement of the stud 23- through the medium of the connection Q2-the eccentric -33 is being slowly rotated about the axis of the stud and effects av corresponding eccentric movement of the yoke --35-u which latter movement is transmitted by said yoke to the arm -18- thereby varying the position of said arm relatively to the stud -23- and axis of the eccentric extension 20- of the main driving shaft -19- and effecting a corresponding gradual lengthening or shortening of the effective distance between the axis of the eccentric extension -20- and axis of the arm 18 at its point of connection with the yoke -35- and causing said arm to move through gradually varying distances within the limits shown by the full lines -18-, Figure 3.

For example, assuming that the stud 23- has been moved to its extreme up position f' by the eccentric -20- through the medium of the connecting rod Q2- and that while at that position the high point of the eccentric -23 is directly over the axis of the stud -23 then the point of conection between the arm -18- and yoke -35- will assume a position as -a--, Figure 3, above the stud --23 equal to the radiusof throw of the eccentric as lindicated by the circular line -a, Figure 3, .thereby amplifying the movement of the arm -18- and lens holder actuated thereby to that extent.

Again assuming that the stud -93 has been moved toits lowest position by the eccentric -20- through the medium of the connecting rod -22- as shown in Figure 3 and that the high point of the eccentric 33- is directly below the axis of the stud then the point of connection between the arm -18-- and yoke -35- will have been moved a corresponding distance below the stud -23- at its lower position shown in Figure 3 thereby further amplifying the movement of the arm -18 and lens holder actuated thereby.

It will be observed however that owing to the drivingconnections between the main shaft -19-` and eccentric -'33 and relative slow speed? of rotation ofthe eccentric extension 20 the position of the` point of connection between the arm #1S-'fand yoke -35- is continually butslowly changing and that atl every change of` this point the stud 23-' is being reciprocated a distance corresponding to the throw of the eccentric ex'- tension +20- thereby causing the arm 18 and lens holder actuated thereby to travel through continually changing paths or fields of action which reduces to a minimum the liability of scoring or otherwise injuring the lens by any errors or'- imperfectionsl in the grinding surface of the lap during progressive grinding or polishing.

I claim: f

1. In a lens grinding and polishing machine of the character described, a grinding element and a lens holding element, a rotary eccentric and a support therefor, means for reciprocating the support with the eccentric thereon at right angles to the axis of rotation of the eccentric, means for continuously rotating the eccentric during its reciprocation, and means actuated by the combined reciprocal and eccentric motion of the eccentric for reciprocating one of said elements relatively to the other element.

2. In a lens grinding and polishing machine of the character described, a grinding element and a lens holding element, a rotary driving member having an eccentric bearing, a rock-arm, connections for transmitting motion from the eccentric bearing to the rockarm including means for continuously varying the distance between the points of connection of said connections with the eccentric bearing and rock-arm as the bearing is rotated, and means for transmitting motion from the rock-arm to one of said elements.

3. In a lens grinding and polishing machine of thev character described, a grinding element anda lens holding element, a rotary driving member having an eccentric bearing, a connecting rod journaled on said bearing member, a rotary eccentric carried by said connecting rod, means for transmitting continuously rotary motion from said driving member to the eccentric, a yoke journaled on the eccentric to be reciprocated thereby and by the connecting rod, and means for transmitting motion from said yoke to one of said elements.

4. In a lens grinding and polishing machine of the character described, a grinding element and a lens holding element, a rotary driving member having an eccentric bearing, a connecting'rod journaled on said bearing for reciprocal movement as the eccentric bearing is rotated, a stud carried by said rod, a rotary eccentric journaled on said stud, means for transmitting continuously rotary motion from the driving member to the eccentric, a yoke journaled on the eccentric -for reciprocation thereby and b the connecting rod, and means for transmittmg the combined reciprocal movements of the yoke to one of said elements.

5. In a lens grinding and polishing machine, a grinding element, a lens-holding element, means including a pivoted frame for supporting and reciprocating one of said elements, arotary eccentric, an arm secured to the frame and having a curved portion substantially concentric with the axis of rotation of the eccentric, and means actuated by said eccentric and operatively connected to said arm for rocking said frame on its pivot, the connection of the last-named means with the arms being adjustable lengthwise of the curved portion of the arm to vary the amplitude of oscillation of the frame and thereby to vary Athe stroke of the element carriedl thereby.

In witness whereof I have hereunto set my hand this third. day of March 1925. i

ELI MAYNARD LONG.

Images