US1282037A - Grinding-machine. - Google Patents

Description

L. W. BUGBEE.

GRINDING MACHlNE.

APPLICATION FILED AUG-21.1916.

1,Q82,@37, Patent-ed Oct. 22, 1918,.

2 SHEETS-SHEET 1.

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GRINDING MACHINE.

7 APPLICATION FILED AUG.21, 1915- I 1 22 3? Patented Oct. 22, 1918..

2 SHEETSSHEET 2.

WITNESSES:

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LUCIAN W. BUGBEE, F SOUTHIBIRIDGE, MASSACHUSETTS, ASSIGNOR TO AMERICAN OPTICAL COMPANY, OF SOUTHBRIDGE, MASSACHUSETTS, A VOLUNTARY ASSOCIA- TION OF MASSACHUSETTS.

GRINDING-MACHIN E.

J Specification of Letters Patent.

Patented Oct. 22, 11918.

Application filed August 21, 1916. Serial No. 116,038.

To all whom it may concern:

Be it known that I, LUCIAN W. BUGBEE, a citizen of the United States, residing at Southbridge, in the county of WVorcester and State of Massachusetts, have invented certain new and useful Improvements in Grinding-Machines, of which the following is a specification.

My invention relates to improvements in grinding machines and has particular reference to a novel and improved machine particularly adapted for use in the construction of bifocal lenses.

One of the leading objects of the present invention is the provision of a novel and improved means for readily and accurately forming the minor or reading portion of a lens having a plurality of focal points.

A further object of the invention is the provision of an improved machine particularly adapted to hold and accurately position therein a finished lens or lens blank and facilitate the formation of a portion thereof to a diflerent curvature to change the lens from an ordinary single focus lens to a bifocal.

A further object of my invention is the provision of an improved machine which may be readily'adjusted to insure exact centerin or positioning of the centers of the two foci of the lens relative to each other and to facilitate the formation of the second curve with a prism or other variation from the power and curve of the major blank as desired.

Another object of my invention is the provision of a novel and improved tool for operation upon the lens and a novel and improved means for insuring a gradual turning movement of the tool to prevent scratching of the lens or formation of wavy surfaces thereon.

Other objects and advantages of my improved grinder should be readily apparent by reference to the following specification taken in connection with the accompanying drawings forming a part thereof, and it will be understood that I may make any modifications in the specific details of construction shown and described without departing from or exceeding the spirit of the invention.

Figure I represents a front elevation of the grinding machine constructed in accordance with and embodying the generic principles of my invention. D

Fig. II represents a side elevation thereof.

F ig.. III represents a plan view of the lens supporting table and associated parts, the remainder of the machine being shown in section as on the line III-III of Fig. II.

Fig. IV represents a sectional view as on the line IVIV of Fig. III.

Fig. V represents a bottom plan view of one of the grinding or polishing tools for use in connection with my improved machine. I i

Fig. VI represents a top plan View of one form of tool.

Fig. VII represents a sectional view as on the line VI-V I of Fig. V.

In the drawings, in which similar characters of reference are employed to denote corresponding parts throughout the several views, the numeral 1 designates the base of my improved machine having rising therefrom the standard 2 provided with the bearings 3 for the lens grinding spindle 4 which is suitably provided with driving means, as the pulley 5, adapted to receive a driving belt 6 for rotating the spindle.

Disposed beneath the spindle and concentrically located with respect to the axis of the spindle is the bearing cup 7 preferably of substantially hemispherical form, adapted to receive the hen'iispherical supporting member or bed 8, which is mounted for rolling movement in the cup 7, any suitable means being employed to lock the bed in desired adjusted relation to the cup, as for example the magnetic clutch or locking members 9 shown in Fig. IV of the drawings, it being understood, however, that any desired equivalent of these members may be en'iploye'd, and it being further understood that the essential feature in the mounting of the bed is that it shall be mounted for substantially universal movement, a hemispherical bed and cup having been here illustrated on account of the ease of locking said parts in adjusted position, but it will be understood that other equivalents such as a double gimbal bearing or the like may be employed if preferred.

Fitting into dove-tail slots on the upper face of the bed 8 are the slides mounted for movement transversely of the-bed, while 'ng projecting of stationary i and having ppleniental slide 13 l lens engaging incinurging the slide toward to resiliently clamp eei, a suitable locksprings sta iionury pins 12 V is 16 therebeti 1r 5 mechanism such a: the set so ew ll servins; t lock the slide 13 in clamped position i securel retaining the lens when ositioned and centered, and preinoi'enient thereof relative to ftw e uni erstood in connection with I description that I have shown d a semi-finished or cut lens as ted within the holder and have described a lens hold-e2. adapted of lens althoug e eniiloyed in conne A i t 'tLlQQl to any other suitable orin which will SifiiSIuCiOLl} anti retain it in desired posireinova aif ii no sl curve of the under face The annulus is h a central poirt i yieldingly or re- 's ooint serving both he center of the lens l aiding in determinnoint on the original lens ninor por- 2O beininent with he grim (i v u al on i c nierely necessary to locking member 1? and the loch- 21 for the carriage plate 11, to at the points 12 and 1 1- until the be placed therebetween the le s t ownwni'd to iiin'ilj; rest upo support 18. Zhe movement it, ,i i i e r e carriage plate 1i i 1.1 men gieiinit oi o the carriage plate 11 with the slides will permit of positioning of the 1')I'Qli6lll'1l11@(l center exactly over the point when the carriage plate 11 will be locked in position through the locking member 21 and the lens being again firmly pressed downward onto the annulus, will be locked into position by tightening of the locking member 17.

It is then desirable to adjust the lens according to whether a prism is to be ground in the minor portion face in or out, up or dowi, this being accomplished by rocking of the bed 8 in the cup 7, to bring the lens into position where the aXis ot' the spindle iwill be normal to the lens or in desired 2121i! to the lens Where ie bed 8 is secured in t d "position b7; the suitable devices 9. The lens is now in position for grinding.

To wind and ish new or minor 1 reterabl provide the s iucie. with the "ably adjustable crank whose onset relatii'eto the spindle adjusted as desired to vary the size the n i or portion, said crank arin 22 having depending pointadupted to be enin the recess 2% of the 'rinding tool )lli IOll This button may be an ordisolid button or cloth covered polished utton such as .illus ste l in Fig. 1V

o and having merely the CQiCQ the pivot or it oi'ed polishing; buttial movement to intial grinding it l ast with a plurality of grooves as illustrated in Figs, 1V and i these grooves leadg toward the center and facilitating flow of the grinding fluid toward the ceit i= of the button and thus insuring a libera usntity of emery or other grinding iiuid being at all times within the tool or lens to j e ent scratching or injuring the lens by the tool and insure rapid g inding.

in the form of tool illustrated in Figs. Vi and 1 have shown the button as comprising t 1e shell or grinding portion 25 recessed in its upoer face to provide the shoulder 27, and the projecting circumferential flange :28 the button having the central countersunk recess or socket 29 to receive the cone point 30 of the disk 31, the cone point being slightly eccentric to the disk whereby the disk at one side will at all times contact with the flange 28 while being out of engagement therewith at the opposite side and the recess 2% being" eccentric to both the pin 30 and the dish 31, as illustrated.

e erabl'y' form the inillil 'ilii insane? In the operation of my imprnwed grinding or polishing button the point 23 of the crank is engaged in the aperture 2 of the disk and a rapid spinning motion imparted to the tool 25 as an entirety, together with the crank on account of rotation of the grinding spindle I. In addition, however, to the spinning or movement in a circular path of the button as an entirety as carried around by the crank arm 22, there will be a spinning or twisting.

movement of the button about the point 23 due to a certain variance in the frictional resistance between the outer and inner portions of the engaging surfaces of the lens and button and also due to the fact that as the button grinds down onto the lens there will be a certain frictional engagement between the side of the button and the edge of the countersink formed in the lens tending to operate as a planetary drive for the button. Additionally, in the form of construction illustrated in Figs. VI and VII, there will be a gradual relative movement of the disk 31 and grinding surface 25 due to the fact that the movement of the crank engaged in the socket 24 eccentric to the disk :25, will cause a certain tilting or rocking movement of the disk 31 on the point 29, each rocking movement temporarily throwing the frictional engaging edge of the disk off the shoulder 27 and flange 28, when the disk will momentarily move without the butt-on, the further rocking movement of the disk again bringing it down into frictional locking engagement with the button to further rotate the button, this movement operating then as an additional break-up to insure against wavy or defective surfaces being formed on the lenses ground.

From the foregoing description taken in connection with the accompanying drawings, the construction and operation of my improved bifocal lens grinder should be readily understood, and it will be seen that it is merely necessary to properly mount the lens to be ground within the lens holder and upon the support 18, to then shift the carriage and bed until the lens is the exact desired relation to the grinding spindle, the curve of the bed and supporting cup being such that tilting movement is substantially about the intersection of the axis of the grinding spindle with the surface of the lens so that the tilting movement will not vary substantially the position to be occupied by the bifocal segment on the surface of the lens, and to then place a suitable grinding tool in engage ment with the surface of the lens and apply power thereto. It will be noted that to cause the relative feed of the grinding tool and lens I have shown the spindle 4: as vertically slidable and provided with the spring 32 to actuate it toward the lens, a suitable latch member 33 being employed to hold the spindle in raised position as desired.

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-gradually fed from the tank onto the lens and will remain in the cup or trough formed by the concave curvature of the original lens blank and thus insure a sufiicient supply of the grinding fluid being at all times on the lens.

I claim:

1. In a machine of the character described, the combination with a base, of a lens carriage plate, slides supporting the carriage plate for longitudinal and transverse movement relative to the base, lens clamping means on the carriage plate to secure the lens for movement with the carriage plate, a grinding spindle, and a lens support mounted in fixed position relative to the spindle for engaging the portion of the lens to be operated upon irrespective of the adjustment of the lens with the carriage plate.

2. In a machine of the character described, the combination with a base, of a tiltable supporting bed carried thereby, a lens we support fixed for movement with the bed, and a lens holding device mounted for sliding movement relative to the bed, said lens holding device spanning the support to retain the lens in engagement With the support.

3. In a lens grinding machine, the combination with a base, of a tiltable bed carried by the base, a lens support rising from the bed, a centering point carried. by the support, means for clampingly securing a lens in engagement with the support, and means for adjusting the lens and clamping means relative to the support.

4. In a machine of the character described, the combination with a base, of a tiltable supporting bed carried thereby, slides mounted upon the bed for transverse movement relative thereto, a lens support mounted upon the bed, av plate carried by the slides, lens rests carried by the plate,

a supplemental plate mounted upon the first plate, additional lens rests carried by the supplemental plate, yielding means for clamping a lens between said rests and locking mechanism for retaining the lens against movement thereof relative to the bed.

5. In a machine of the character described, the combination with a base, of a tiltable supporting bed carried thereby, 139

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mounzed upen the bed for rensverse relative thereto, a lens support of an annulus mounted upon he ring; peint carried by the supurried by cue slides, lens rests 1 1' :he plate, a supplemental plate as first plate, additional lens V ihe supplemental pla ce 101' clamping a lens betweezl

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