US772431A - Machine for grinding lenses. - Google Patents

Description

. 110.772,431. y* PATENTED 001218', 1904.

' c. L. RAMEAU.

MACHINE POR GRINDING LENSES.

` APPLIOATION FILED nu ze. 190s. No MODEL.4 a slums-SHEET 2.

No. 772,431. PATBNTEDOGT. is, 1904.

. .0. L. YMmmm.

MACHINE POR GRINDING LBNsBs.

, APPLIUATION FILED In '26. 1903.

NO MODEL. 3 BRIEFS-SHEET 3.

. i l /IZ f@ 'nfroHA/EXS ,Patented October 18, 1904.

- UNITED A"STATES PATENT OFFICE.

`CLAUDE LOUIS RAMEAU, OF PARIS, FRANCE.

MACHINE vForaela'naolnle LENSES.

SPECIFICATION forminglpart of Letters Patent No. 772,431, dated October I8, 1904. .ippncason ined May 26,1903. serial No. 158,870. (No model.) 1

To a/ZZ whom tm/(ry concern:

Be it known that I, OLAUDELOUIS RAMEAU, civil engineer, a citizen of the `Republic of France, and a resident of No. 11() Rue dAngoulme, Paris, in the Republic of France, have invented certain new and useful Improvements vin Machines for Grinding Lenses, of which the following is aspeciiication.

This invention relates toimprovements in machines for grinding' lenses.

Machines for grindinglens-surfaces gener- 'ally1 consist of two disks, either plain, convex,

or concave, the lower disk being fixed or adapted to turn very slowly about its axis and the upper one movable, with its center usually describing a circle around the axisof the lower disk. In this movement the grinding material, such as pulp or dust, is constantly thrown toward the circumference and the grinding of the lens-surface is effectedin an unequal and irregular manner. It would therefore be a great advantage to cause the center of one of the disks to describe round the fixed axisof the other disk a curve, so that the grinding material after being thrown toward the circumference would bebrought back toward va complete elongated and closed epicycloid.

Fig. 3 is a vertical sectional View of the device employed for producing the epicycloidal movement of one of the disks. Fig. 4 is a horizontal sectional view through line A B of Fig. 3. Figs. 5A and Gare detail plan views of the device illustrated in Fig. 3. Fig. 7 is a whole elevation view of a model of construction of the new machine. Fig. 8 is a plan view'of same." p

It is known that the epicycloid is the curve generated by a point of a movable circle which rolls without sliding on a steady circle. If the circle B C rolls on the circle O A, Fig. l,

each point of the circle B O will describe an ep'icycloid.v If the point considered is on the circumference of -the circle B C, the curvev 1 or normal epicycloid will be obtained. If the point .is inside the circumference, a shortened epicycloid will be obtained, of which the circle 2 described bythe center B isa special case. Finally,- if the point is taken out of the generating circumference, as at D, for` instance, the buckled curve 3 or ,elongated epicycloid will be formed. Fig. 2 shows this. elongated epicycloid entire and closed after a suitable number of revolutions. kIt is mainly thispath that one will seek to impart to the grindingdisk during'the working of themachine.

Themachine comprises a standard a, supporting the different parts, a driving-shaft b, a vertical shaft c, on the upper end of which Yis secured the lower disk d, and a second vertical shaft e, which carries the upper disk f by means of ajoint hereinafter described. The

lens-surfaces to betreated and the grinding material are placed,as usual,betweenthe disks Z and j'. `The first vertical shaft c is given a slow rotary movement from the driving-shaft v through suitable gear---for instance,'a pair of toothed wheels g and 7L, a worm c', mounted on the shaft j', and a worm-wheel Z6, secured to the vertical shaft c and gearing with the worm The shaft e receives a rotary movement from the driving-shaft Z2 through suitablepulleys Z'm n and a belt p. This shaft e carries a head q, resting on balls r, rolling in annular races in a part fixed to the frame.

The said shaft is prolonged below the head q and carries a pinion s, gearing with another pinion t. These two pinions, of which the number of teeth are prime one to each other,

.are mounted in a hoop or'frame u, which is end a horizontal plate e, having three parallel slots or recesses 5, into which engage bolts or pins 6,iiXed to a tube or sleeve 7. This sleeve carries the shaft 8, which drives the upper grinding disk. An elastic connectionformed, for instance, by a helical spring 9- maybe interposed between the plate and the shaft which moves it. Owing to the grooves in the plate z and the said fasteningbolts the shaft 8 of the sleeve can be made to coincide with the shaft y of the plate a or be moved therefrom. By these means it is possible for any point on the grinding-disk to describe a normal, elongated, or shortened epicycloid.

Having now described my invention, what I claim as new,and desire to secure by Letters Patent, is-

1. A machine for grinding lens surfaces comprising a lower grinding-disk, a second grinding-disk above the same, a vertical shaft,

a frame rotatively carried thereby, a connection from said frame to the upper disk` means for rotating said connection and means for rotating the shaft, substantially as described.

2. A machine for grinding lens-surfaces comprising a lower grinding-disk, means for rotating said disk, a second disk above the first, a vertical shaft e, aframe rotatably7 carried thereby, a shaft y carried by said frame,

a shaft Scarrying the upper grinding-disk and an adjustable connection between shaft y and shaft 8 and means for rotating shaft e, substantially as described.

3. A machine for grinding lens surfaces comprising a grinding-disk (Z secured on the upper end of a vertical shaft c, means for causing said shaft c to turn, a second grindingdisk f arranged above the first one, a vertical shaft 8 pivotcd centrally on the top of the disk f, a sleeve 7 in which is arranged the shaft 8,a plate provided with parallel grooves 5, bolts 6 engaged in said grooves and securing the sleeve to the plate in the proper position, a vertical round shaft ,1/ fixed on the upper surface of the plate .2', a pinion mounted on the shaft g//, a vertical driving-shaft e arranged parallel to thc shaft 1/ and guided in the frame, a pinion s mounted on the shaft e and gearing with pinion f', a head r] integral with the shaft e and resting on balls carried by the frame of the machine, a hoop or frame u fixed to the shaft e and loosely passed over the shaft z/, and means for causing the shaft e to turn, substantially as and for the purpose set forth.

In witness whereof I have hereunto set my hand in presence of two witnesses.

CLAUDE LOUIS RAMEAU.

fitnessesz ANTOINE HAvoIX, AUGUSTUS E. INGRAM.

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