US940978A - Machine for grinding the surfaces of lenses. - Google Patents

Description

E. M. LONG. MACHINE FOR GRINDING THE SURFACES or LENSES.

APPLICATION FILED MAY 21, 1906. v Patented Nov. 23, 1909.

3 SHEETS-SHEET 1,

WITNESSES.

flTTURNEV rum. Inc mm vus E. M. LON G. MACHINE FOR GRINDING THE SURFACES OF LENSES. APPLICATION FILED MAY 21; 1906,

940,978. Patehted'Nov. 23, 1909.

3 SHEETS-SHEET 2.

4 2 ara; 20 1 58 m :2 /7

, a 28 Z 7 52 I l 5 3 I. '2 M. i f 1 W flTTORZVEl E. LONG. MACHINE FOB GRINDING THE SURFACES 0F LENSES. Arrmpnmgw FILED my 21, 1906.

WITNESSES INVE' TOR ATTORNEY UNITED-STATES PATENT OFFICE,

ELI l oNG, or GEnEvA,---NEw"YoaK,' assrenoaro HE STANDARD OPTICAL ooM- raw, or G NEVA YORK, A. CORPORATION or NEW YORK.

,MAcHInE FOR cninnme THE sUnEacEs or LENSES.

Be itknownthat 1, ELI M. Lone, of Geneva, in the county of Seneca, in. the S'Qate of New York, have invented new and useful Improvements in Machines forGrinding the Surfaces 0f Lenses, of whichthefollowing," taken in connectionwith the accompanying drawings, is a full,' 'clear,. and exact-description. v

This invention relates to certain improve ments in machines for grinding the surfaces of lenses, and contemplates an attachment.

adapted to-be applied to any availablerotary shaft or spindleof similar or different -ma'chines for automatically grinding the surface of the-lens to a predetermined contour. 'In ,other words, the invention in volves the use of a: grindingbed or lap and a which parts is caused to traverse the surface of the other to bring the surface of the lens into.

exact coincidence with thegrinding surface of the lap.

The abrasive or grinding material usually consists of emery dust or powder placed upon the surface of the lap to Contact with and reduce the surfaceof the lens to the desired contour, and it, therefore, becomes necessary to protect-the greater portion of the power transmitting mechanism from accumulation of emery-dust or powder thereon,

. ment-throug which would soon 'causeexcessive abrasion.

or wear of the workin parts, thereby impairing the working efficiency of the whole device. v

One of the essentialobjects of this invention is to-inclose the working parts of the power-transmitting mechanlsm ;m a dust-- proof case calculatedto exclude theemerydust or powder \vhichis used for grinding.

Another. obj ect is to associate the grinding bed or lap and lens holder in such manner that one of the parts may be caused t0jtrav-' erseback and forth across the other in serpentine curvilinear paths, but not in coincident hnes sothat the 'rnovln art chan es its lineof travel at each sweep." This latter .object, more specifically stated, is 'to mount the le'nsholder upon an oscillatory frame having a comparatively long sweep through one median line,a1'1d a shorter sweep through a second median. line and in a plane at sub}, stantially ri ht angles-to the plane move %1 the longer sweep so that while Specification of Letters Patent. Patented Nov. 23, 1909. Application filed May a, 1906. Serial mama.

" .the lens caused to travel back and forth from one extreme point to another, it is continuously diverted from 'a direct line between said points, thereby'traveling in a serpent-inc path across and to opposite sides of such line, p p I Another object is to cause the lens to travel across the grindingsurface of the lap in different serpentine paths so asto distribute theabrasion or grinding evenlyover the entire surface of the lens without liability of cutting objectionable channels or grooves'therein. In other words, I have sought to impart a double oscillatory move- .ment to the lens holder or grinding bed, as the case may be, through the. medium of suitable eccentrics driven from a single rotary spindle or shaft whereby the lens is caused to swing through difierent arcs at} substantially right angles .to each other.. Other objects and uses will be brought out in the following description.

In the drawings- Flgure 1 is aside ele V vatlon of a lens surface g'rmdingdevice em- 9 bodying the features of my invention. Fig.

2 is a top plan'of' the same with the ripper half of the casesection'removed showing the interior-construction; Figs. 3, 4, 5, and 6 are sectional views taken respectively on lines 3--3, 44, 55, and 6' 6, Fig. 2, ex cept that the eccentric for the long sweep andparts actuated thereby are shown in one of the extreme positions in Fig. 3, while the i eccentric for the short sweep and parts actuatedth'ereby, are shown in one ,ofthe' ex,-'

This machine is especially-adapted for,

treme positions in Fig. 4.

automatically grinding the surfaces of toric, cylindrical and other compound lenses or curved surfaces of different radii, and'comprises essentially the grinding" mechanism movable element of the grinding mechanism,

195 proper and actuating mechanism for the and adust proof case'or housing inclosingp one of said mechanisms to exclude the emery-dust from the working parts of the actuat ng mechanism. v

, The grinding device proper-consistsofa v impart similar movement to the lens, asv

"bed or lap .1-- of. cast metal or other Suit-. able materialland a lens holder, as a metal disk- 2, one of which parts,. in this in;

stance, the lens holder, is adapted to traverse.

the ,grindingface of the 1ap.+l' 'andto 3, which is held between the lens holder j and lap and is rigidly secured by cement or other fastening means, to the lens holder.

The grinding bed or lap 1. is removably seated upon a rigid supporting bracket -4, its upper face being formed to the desired contour forming a counterpart of that to which the surface of the lens is to be ground and in this instance, is concave and receives a suitable quantity of powder emery to form a corresponding convex sur- 'face on the lens. The lower side of this bed is formed with recesses or sockets 5 to receivepins --6- which project upwardly from the supporting bracket -4 and permit the bed to be readily removed and replaced by a lap'of different contour when desired to-grind the surface of a different lens, the bracket 4 forming a part of the main supporting frame,

The lens holder 2. and its lens 3i are'moved across the grinding face of thelap 1 by means of a vertically swinging yoke 7'- which forms a part of theactuat- 14 and a shoulder 15 on the plunger to force said plunger and yoke --7 downing mechanism, said yoke being pivoted at 8 to an oscillating member 9 and has its free end spring pressed downwardly by a plunger l0-'--and spring l1 so as to hold the surfaceof the lens in yielding pontact with the grinding surface of the the lens holder 2 by what may be termed a universal joint, comprisin a pair of pins 12 which bear iii-suitable sockets 13- in the upper face of the lens holder 2 to permit said lens holder to oscillate with reference to the yoke 7 therebyenabling theflens to readily conform to the contour of the grinding surface as the lens hiplder is reciprocated back and-forth across s id surface. The lens holder -7-' is also engaged with the plunger 10 by, what may be termed a universal joint, which The'upper end of the plunger -10 is loosely seated in one end of a vertically adjustable arm l-ft' to allow said arm to oscillate to conform to the movement of the lens holder, the spring -'11 being interposed between the lower face of said arm wardly, thereby holding the lens against the grmdmg surface during its traversing movement across said surface.

I 'The lower end of the plunger 10 is loosely connected to the intermediate por-' tion of the yoke 7 by means, of a link The yoke 7 is loosely connected to ture --17 in the arm 14- and is held from downward movement by a cotter-key or equivalent holding means --18, said aperture being elongated laterally to permit the free oscillation of the plunger, which latter may be moved upwardly against the action of the spring -1 1 to disengage it from the lens holder.

The arm '14- is vertically adjustable upon a fixed rod l9' for the purpose of varying the tension of the spring l1., thereby varying the degree of pressure of Y the lens upon the grinding surface, said arm 14 being locked in its adjusted position by the'act-ion of the spring 11 which tends to cramp and to frictionally hold the arm in engagement with the standard 19. v

The extension 9 to which the yoke 7- is pivoted forms a part of an oscillatory frame 19- whichis adapted to swing on different axes at right angles to each other and preferably disposed in coincident planes.

As shown in the drawings, the oscillatory frame -19 is pivotally suspended from a shaft -20, which in turn, is pivoted near one end upon a suitable bearing 21, the axes of the bearings 20- and -2l being disposed at right angles to each other and in coincident planes to permit the 0s: cillation of the frame 19-.1n't wo vertical planes at right angles to each other, and to impart similar motion to the yoke -7- and lens holder through the medium of the err-- tension 9 which connects the lower end of the frame 19 to the y0ke7-.

The end of the bearing .20'- opposite the pivotal bearing 2l is loosely connected to one arm, as -2Q, of a bell cranklever, which in turn, is pivoted at -23' to a fixed support '-24-- and has its other arm.

provided with a journal bearing a5in which is seated a rock-shaft or spindle 26--.ha-ving a socket 27--. Journaled in this socket is a spindle -28 which is cccentrically secured to a pinion 29' on the upper end of a driving shaft -30 so frame 19. j The pinion '"29 meshes with a somewhat larger gear -29". which is journaled in the dust-proof 'case' presently described,

and is provided with an upwardly project- I so - emp re placed thereon and is rigidly locked to rotate or equiv-- with the=gea r -'-29'- by a set screw alentfaste'n'lng means 33 non 'rotatable annulus-3el separate from the gear +29 and is connected by a yoke link to the lower portion of the oscillatory fra1n e 19- through the medium of a ball and socket joint -3 6, best seen in Fig.

3-. This link servesto impart a rock- "lng niotion from theeccentric' -32 to the frame 19:-- the throw of the eccentric beingfsiufiicient to move the lower end oi the frame -19 through. a considerable arc, thereby impartingisimilar motion-to the lens holder to reciprocate the lens back and forth froni'one extreme end to the other of the 'long'jaXis'of the bed plate or lap 1 and during such movement the frame -19- is osc llated laterally in opposite directions p p h piv t j21+, through the medium of the eccentric and bell crank co niected thereto, thereby imparting a similar, but-comparatively short lateral move-- ing thefrecurrent intermeshing of the same teeth of, both. gears except at long intervals,-

which; causes; the lens" to travel back and *forth a'cross the grinding surface in different "curvilinear or serpentine paths, and

thereby avoids anyfliability of channeling or unduly grooving the lens,,.as would be the case if the lens were allowed to travel'in the same path. The essential feature of this actuating mechanism is that or oscillating the frame ,-.'19f--fr0m-two different axes in the same horizontal plane and at rightangles toeach other to impart a long sweep and a comparatively short lateral sweep to the lens-across the grinding surface, theshort lateral sweep' recurring several-times during each long sweep fromone extr me to the other, the number of recurrences of the short sweep depending: uponj'the relative size of the pinion 29s with reference to the gear ,1- 29 In this-instance the pinioniis com-v paraltively small and causesits eccentric-pin 28 to oscillate the bell crank lever and frame. "419' connected thereto rapidly ba'ck and' fort a predetermined numberzof times'klu'ring each cycle of movement of the necessary. to connect withthe spindle -30-.,

' to which the pinion -29-. is secured, and in v attaching my improved grinding device to any similar or other machine it is simply i or mount the pinion 29 upon thespindle with which-the other machinemay be provided.

Ihave now described the grindin'gmech anisin proper, and.also the mechanism for, 80. 'actuatingone of the movable parts, as the lens holder, and inasmuch as the accuracy and efficiency of the machine depend upon the close fit and harmonious working of the various parts of the actuating mechanism, it '85 is desirable to protect such working parts from the accumulation of'emery-dust which maybe liberated from the grinding inechv anism, and I' therefore, incjlose practically. .the entire actuating mechanism within a I dust-proof case composed of lower and upper sections -3'2' and -38 which are closely.- fitted together and clamped bysuitable fastening means, as screws, 39 said case sections being divided horizontally so that the upper section may be removed readily without disturbing any'of the parts of the actuating mechanism.

The lower caseisection is provided withLa depending hub -4O which receives a bush 1 on ing ,4l in whichthe shaft -30 is journaled, and this hub enables the whole device to bo clamped place upon'a similar niachine;

with suitable oilv cups .-4l2-' having leads I for directing-the oil to various bear ings of'the actuating mechanism Within the case without removing the upper SQCtIQIL the manner just described, the grinding mech anism is outside of thec'ase and is only'connect ed to the actuating mechanism by the extension ,9- which enters the bottom of the lower 44. of suflicient dimensions to permit the lengthwise and lateral oscillation ofsaid ex tension therein. v

WhatI claims, 3

of lenses, an oscillatory frame and a rocking supporttherefoi',the swinging axes of the. frame and support intersecting each other atright angles, combination with a' drivlng v shaft, means actuated by the shaft for rock-K 5- ing. said 1 support, additional means actuated by the same shaft forfoscillating said -frame upon its support, alap and a' lens holder 0 'coacting therewith to grind 'the lens,j-and The'upper casefsection -38 is provided 105,

3 By inclosing the actuating mechanism in case sect-ion -37 through an aperture 11 1.1; In a machine for grinding the surfaces.

"means for transmitting "motion from the :45 9

cillatory frame to the lens holder whereby the latter is'moved in serpentine paths rela-' tively to the lap. '2. In a machine for'grinding the surfaces oflenses, a lap, a lens holder movable in two directions at substantially right angles to each other, and mechanism for actuating said lens holder comprising a driving shaft, and separate i-ntermeshing gears driven by said shaft and having eccentrics of different throw whereby the lens holder. is caused 'to. move back and forth in serpentine paths.

'3. In amachine for grinding the surfaces I of lenses, a grinding element and a lens holding'element,- one of said elements being movable back and forth in serpentine paths across the other element, and mechanism for actuating the movable element including an oscillatory frame and-a rocking support therefor, the swinging axes of'said frame and support ,being disposed inthe samehorizontal pla'nes'at substantially right angles to each other.

4. In a machine for grinding the-surfaces of lenses, a grinding element and a lens holding element, one of said elements being movable back and forth-in serpentine-paths across the other element, and mechanism for actuating the movable element lncluding 1ntermeshing gears and eccentric members thereon for changing its path of movement at the. end of each stroke whereby said mov-' able. element is prevented from traveling twice in the same path.

- 5 In a machine for grinding'the surfaces of lenses, a grinding element and a lens.

holdingelement, one'of said elements being movable back and forth in different serpentine paths across the other element, and

mechanism for actuating said movable ele-' nected to-t-he swinging frame, the Ifuinber of.

teeth of one gear being indivisihle by that of the-"other gear whereby the movable ele ment is caused to change its path 'of movement during each cycle of operation.

. 6. In a machine forgrinding the surfaces of lenses,a :'grindii1g element, and a lensholding element, one of said elements being niovable back andforth serpentine paths across. the other element an oscillatory frame-moving in two directions at right angles to each otherand connectedv to the mov able element, a rockingy'support for said frame for imparting .one movementthereto, a driving shaft provided with a pinionhaving an eccentrlc bearing, connections "be-' tween said eccentric bearing and rockingsupport for imparting rocking movement to lap,

frame and support same horizontal planes, and a rock arm fulment including arr oscillatory-frame and..- rockingsupport thereforhaying its swing-J ing axis in a plane-at substantially right faces of lenses, a stationary lap, a

throw for-moving the lens holder'and bearing journaled therein and engaged =W1tl1 the latter, a gear meshing with the. pinion and also provlded with an eccentric bearin movable back and forth in serpentine paths across the other element, yielding means for pressing one of the elements toward the other, and mechanism for actuating the -movable element including eccentrics and operating gears therefor, one of said gears having a number of teeth indivisible by the number of teeth of the other 'gear for cha ing its path of movementof the movab e element at all points in. its line of travel after the first operation.

8. In a machine for grinding the surfaces of lenses, a lap, a lens holder movable back and forth in serpentine paths across-the lap, an oscillatory. frame and rockingr therefor, the swinging axes of the aim and support intersecting each other at substantially right angles, a yoke ivoted to the frame and bearing upon the ens holder, an oscillatory plunger spring-pressed against the yoke to force the lens holder toward the and mechanism for imparting oscillatory movement'to the frame and its sup ort.

9. In a machine for grinding the sur aces of lenses, holding element, one of said elements being movable relatively to the other element, and mechanism for element including a swinging frame and rocking support therefor, the axes of said being disposed in the.

crumed on a different axis from those of the frame and support, a driving shaft, means for transmitting motion from the driving shaft to the'rock arm, andfseparate meansfor transmitting motion from the shaft to the frame.

'- 10. In a. machine for grin the ur- I ens der movable relatively'to said lap, an oscilla toryplunger. supported at one end and havth .la and yieldin l ress 'thelens ho der toward said, a iid nig hanism in cluding 'separate' eccentrics of diffei'entladjg; cent end. of the plungerlin different curvi-. linear paths at each cycle of o eration'. "11. In a machine for grin .tIIeSIJLrfaces of lenses, a driving driven by said shaft, a rock arm ha' a said'eccentriqan oscillatory frame actuated by said rock arm in one direction, means actuated by the shaft for rocking saidframe in a direction substantially at right angles support a grinding element and a lens actuating the movable 111.5 ng 1ts opposite end spring pressed toward shaft, an eccentric .125

'fac'e s'of lenses, a dust-proof hon-sing having to the first named direction; av lens ho1der,:

and means for transmitting motion from theoscillatoly frame to the lens holder. l 12. Ina, machine for grinding the-surehub, a driving shaft journaled' in the hub,

' a bracket secured to the housing, a.1' ap' mounted on the bre cket exterior to the housing, a lensholgder spring pressed toward the 1ap,-a11 oscillatory frame movable in difierent directions at substantiallv-right angles to each other, means for transmitting fl1'n0 tion. from the oscillatory flame to the lens holder, and mechanism within the housing and driven by said shaft for oscillating said 5 frame.

In witness. whereof I have hereunto set 'my hand this 14th day ofMay 1906. j ELI M. LONG. Witnesses: SMITH A. H RRIMAN,

EpwARn SJ BOYDEN.

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