US2212179A - Lens grinder - Google Patents

Description

J. H. MARTIN LENS GRINDER Aug. 20, 1940.

Filed Dec. 20, 1938 4 Sheets-Sheet l INVENTOR.

ATTORNEYS.

J. H. MARTIN LENS GR INDER Aug. 20, 1940.

'4 Sheets-Sheet 2 Filed Dec. 20, 1938 \QlmNm IN V EN TOR.

I BY

I ATTORNEYS.

J. H. MARTIN Aug. 20, 1940.

was GRINDER Filed Dec. 20, 1938 4 Sheets-Sheet 3 I- w N w N Qm 1 l Wm ilw mw V I dym v Ff In N 2 k 1 M W JEJMQWZZ'W/ INVENTOR.

ATTORNEYS.

J. H. MARTIN mus GRINDER Aug. 20, 1940.

Filed Dec. 20, 1958 4 Sheets-Sheet 4 ezgwflzik INVENTOR.

ATTORNEYS Patented Aug. 20, 1940 UNITED STATES PATENT OFFICE.

was GRINDER Joseph Barry Martin, Roanoke, v... Application December 20, 1938, Serial No. 246,887

4Claims.

The objects of this invention include the provision of a simple but effective mechanism whereby any curvature may be ground into a lens, without changing grinding wheels, and with a flatsurfaced wheel, novel means being supplied for mounting and actuating the movable parts in such a way that the result above alluded to may be accomplished.

It is within the province of the disclosure to improve generally and to enhance the utility of devices of that type to which the present invention appertains.

With the above and other objects in view, which will appear as the description proceeds, the invention resides in the combination and arrangement of parts and in the details of construction hereinafter described and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed, may be made within the scope of what is claimed, without depart: ing from the spirit of the invention.

In the drawings:

Fig. 1 shows, in side elevation, a lens grinder constructed in accordance with the invention;

Fig. 2 is a top plan;

Fig. 8 is a fragmental section on the line 33 of Fig. 2;

Fig. 4 is a front end elevation;

Fig. 5 is a section on the line H of Fig. 1;

Fig. 6 is a section on the line 6-4 of Fig. 2;

Fig. 7 is a section on the line 1-1 of Fig. 6;

Fig. 8 is an elevation showing a modification;

Fig. 9 is a diagrammatic view referred to in connection with the description of the operation of the device. I

For convenience in describing the relative locations of parts, that end of the machine to which the reference character A is applied will be considered the forward end, the rear end of the machine being marked by the reference character B.

The device forming the subject matter of this application comprises a bed I (Fig. 1) secured by legs 2 to a table 3. Near its forward end (Fig. 2) the bed I is supplied with a laterally extended and upwardly projecting bearing standard 4 (Fig. 4) and in the bearing 4, a shaft 5 is journaled, the shaft being disposed transversely with respect to the length of the machine. A grinding wheel 3 is secured to thrinner end of the shaft 5 and is disposed in the longitudinal axis of the machine as shown in Fig. 2.

The shaft 5 is supplied (Fig. 4) at its outer end, with a worm I, meshing with a worm wheel 8 journaled on a shaft 9 carried by an arm it projecting outwardly from the bearing standard 4.

A drive shaft ll (Fig. 2) is supported for rotation in any suitable way (not shown) and is located below the table I. A belt and pulley drive 5 l2, depicted in Figs. 1 and 2, constitutes means whereby rotation is imparted to the shaft 5 and the grinding wheel 6 from the shaft ll.

A slide or support I 4 (Fig. 3) is mounted for right lineadjustment, toward and away from the 10 grinding wheel 6, in a guideway (Fig. 5) formed in the bed I. For the adjustment of the slide I 4, toward and away from the grinding wheel 6, there is provided such a mechanism as a feed screw II (Fig. 3) threaded into the slide ll, and held for rotation but against longitudinal movement in the rear end of the bed I. An elongated base member l6 (Fig. 2) is located above the slide I4 and bed I, and intermediate its ends, the base member I6 is mounted to swing horizontally, and transversely of the plane of rotation of the grinding wheel 6, on a fulcrum screw I1 (Fig. 3) carried by the slide it.

A bracket l8 (Figs. 1 and 4) is secured to the forward end of the base piece It and may be consideredpart thereof. On the forward portion of the bracket I8 (Figs. 1 and 4) there is secured an upstanding post IS. A transverse pitman (Figs. 4 and 2) is provided, the inner end of the pitman 20 being connected by a ball and socket joint to the post l8. Figures 4 and 1 show that a crank 2| is connected to the worm wheel 8, to turn therewith. The outer end of the pitman 2' is connected at 22 (Fig. 4) to the crank 2], for adjustment longitudinally of the crank.

The numeral 23 marks a carriage (Figs. 1 and 4), the carriage comprising an elongated base 24 and upwardly projecting standards 25. As shown in Figs. 4 and 5, for instance, the base 24 of the carriage 23 is mounted on the member It for adjustment longitudinally thereof, toward and away from the grinding wheel 6. A set screw 28 or other holding device (Fig, 1) carried by the base 24 of the carriage 23, maintains the carriage in any position to which it may have been ad- 5 justed, lengthwise of the member l6. Figure 2 shows that at one side the base 24 of the carriage 23 is provided with a longitudinal scale 2l, adapted to cooperate with an index 28 secured to the edge of the base piece l6. 50

The standards of the carriage 23 carry a fulcrum pin 29 (Fig. 2) on which a lever or guide 30 is mounted, between the standards 25, for vertical swinging movement, that is, in a direction at right angles to' the axis of rotation of the grind- 55 ing wheel 3. Figure shows that the lever 33 is the grinding wheel 3.

trough-shaped in cross section.

Mounted for longitudinal adjustment in the trough-shaped lever 33 is the shank 31 (Figs. 1, 2 and 5) of a work carrier 32, including an arcuate head 33 (F18. l) convexed longitudinally toward The lens blocks L which are to be ground, are cemented or secured otherwise to the head 33 of the work carrier 32. It

appears in Fig. 2 that shank 3i of the work carrier 32 is supplied with an elongated slot 34, co-

operating with a holding device 33 on the lever,

33, to retain the work carrier 32 in any position to which it may have been adjusted lengthwise.

On the upper surface of thelever 33 there is a longitudinal scale 33 (Fig. 2), cooperating with an index 31 on arier 32.

Figures 1 and 6,show that a transverse shaft 33 is mounted to turn in a lateral tubular ;bearing 33 (Fig. 2) which is carried by one of the standards ,23 of the carriage 23. The shaft 33 is driven from the power shaft II, by a belt and pulley connection 43, shown in Figs. 2 and l.

h A pinion 4| (Figs. 6,4 and 5) is secured.to the inner end of the shaft 38 and meshes with a gear'wheel 42, journaled on a stub shaft.

.(Fig. 7) mounted in one of the standards of the carriage 23. The gear wheel 42 is supplied with a circular, eccentric track 44 (Fig. 6) receiving a roller projection 43 (Fig. 7) carried by the lever 33 (Fig. l) and located behind the element 28 on which the lever swings vertically with respect to the carriage 23. I

Bymeans of the feed screw I! of Figs. 1 and 3, the slide l4 can be adjusted to bring the lens blocks L up to the grinding wheel 3, the feed screw constituting means for producing relative movement between the work carrier 32 and the wheel 3, to position the lens blocks L properly for grinding. When the slide I4 is advanced with respect to the grinding wheel 3, the parts participating in that movement are the base member l3, the carriage 23, the lever 30 carrier 32. I 1

- -As to the rotation of the grinding wheel 6, that operation is brought about by the belt and pulley l2 of Figs. 1 and 2, the grinding wheel shaft 3, and the drive shaft ll.

The lateralswinging movement of the base member l3 (Fig. 2) on the pivot screw I1 that is carried by the slide I4, is accomplished by a train of parts including the bracket i3 (Fig. 1) on the forward end of the base member it, the post I! of Fig. 4, the pitman 20. the connection 22, the crank 2|, and the worm wheel 3, the worm wheel being rotated by the worm I on the grinding wheel shaft 3. 1

The vertical swinging movement of the work carrier 32 is produced by a train of parts including the drive shaft ll of Fig. 2, the belt and pulley drive 43-of Fig. l, the shaft 38, the pinion 4! (Fig. 6) the gear wheel 42 supported at 43 on one of the standards 25 of the carriage 23, the eccentric groove or track 44 on the pinion 42, and the roller projection 43 which is carried by the lever 33 of Fig. 1, vertical tilting movement being imparted to the lever 30, on its fulcrum 23, the work carrier 32 participating in the vertical tilting movement of the lever 33.

The character 1' may be taken to represent the radius of curvature longitudinally of the axis ing the shank 3i of'the work carrier 32 in the the shank 3| of the work car-v and the work -the "6 mark on the scale 33. The radius r,

The character B may be taken to represent the radius of curvature along the axisX-X of Fig. 9, the origin of the radius It being the fulcrum pin 29 that connects the lever 33 to the standards 23 of the carriage 23. The grinding to produce cur- I vature on the radius r is brought about by the lateral swinging movement of the base member It on the fulcrum screw ll of Figs. 2 and l, and the grinding to produce the curvature on the radius R is brought about by the vertical swinging movement of the lever 30 and the work carrier 32 with respect to the fulcrum 23 of the lever.

The radius R can be varied in length by shiftof the index 23 and the scale 23 of Fig. 2.

Lens blocks for the kind of work done in the machine herein disclosed, come to the optician from the manufacturer .with the inside surface (the surface cemented to the head 33 of the work carrier 32) finished to a minus six diopter curve. Figure 2 shows the machine set for grinding a piano lens. The index 23 registers with the 6 mark on the scale 21, and the index 31 registers with the 6" mark on the scale 33. The outside of the lens block will be ground to a plus six diopter curve, but since the inside curve is a neutralizing, minus six diopter curve, the resulting product will be a piano lens.

In order to grind a piano-cylinder, the radius R, representing the vertical swing of the work carrier 32 longitudinally of th( axis X-X, remains unchanged, the index 31 cooperating with representing the horizontal swing of the base member i6 and all parts carried by it, longitudinally of the aids Y-Y, is changed, say by moving the carriage 23 until the index 23 cooperates with the 7" mark on the scale 21. The resulting product is a plus one diopter cylinder.

In order to grind a compound surface, the work holder 32 is moved until, forexample, the index 31 cooperates with the 7'? mark on the scale 36, the radius R being altered. The carriage '23 is moved until, for instance, the index 23 cooperates with the "8" mark on the scale 21. The resulting product will have a plus 0!l8 diopter sphere combined with a plus one diopter cylinder.

The foregoing examples make manifest the possibilities of the machine in grinding curves other than those specified. Especial attention is directed to the fact thatthe device grinds a cylinder and a sphere on the, same surface in one operation in an arc, the origin of the radius of Q the arc in Fig. 1 being the fulcrum member 23, and the origin of the radius of the arc in Fig. 3 being the axis of rotation of the shaft 23a.

The construction of the machine is such that any desired curvature may be ground, regardless of the shape of the wheel 3, that is, whether the wheel is flat, convexed transversely at its periphcry, or even if the wheel 6 was of irregular shape,

because it happens to be somewhat out of condition at its circumference. The curves of the lens surface do not depend upon the configuration of the grinding wheel.

In Fig. 8 of the drawings, parts hereinbefore described have been designated by numerals already used with the suffix a. In this form of the invention, the fulcrum member 29 of Fig. 1 becomes a power driven shaft 290, operated by a pulley 46 and a belt 41, the work carrier 32a being a wheel, to the periphery of which the lens blocks are attached. The work carrier 32a receives continuous rotary motion, instead of the oscillating motion imparted to the work carrier 32 of Fig. 1, but in either form of the invention, the lens blocks are presented to the grinding wheel.

What is claimed is:

1. In a machine for grinding lenses of different curvatures on a single grinding wheel, a grinding wheel, means for mounting the grinding wheel for rotation about an axis, a support, a base member, pivot means mounting the base member on the support for swinging movement in a plane disposed substantially parallel to the axis of rotation of the grinding wheel, a carriage, means for mounting the carriage on the base member for right-line adjustment toward and fromthe pivot means, a lens carrier including a part holding a lens block in operative relation to the periphery of the grinding wheel, and means for so mounting the lens carrier on the carriage that said part of the lens carrier can move in an arc and in a plane substantially at right angles to the axis of rotation of the grinding wheel, the lens carrier participating in the aforesaid movement of the carriage, toward and from the periphery of the grinding wheel, and participating in the aforesaid right-line adjustment of the carriage with respect to the pivot means.

2. A machine for grinding lenses of different curvatures on a single grinding wheel, constructed as set forth in claim 1, in combination with mechanism independent of the means for mounting the carriage on the base for right-line adjustm'ent toward and from the pivot means, for mounting the support and the grinding wheel for relative movement toward and away from each other, thereby to secure a grinding relation between thegrinding wheel and a lens block on said part of the lens carrier.

3. A machine for grinding lenses of different curvatures on a single grinding WheeLconstructed as set forth in claim 1, and wherein the means for mounting the lens carrier as set forth in claim 1 is a guide supported on the carriage for tilting movement about an axis substantially parallel to the axis of rotation of the grinding wheel, the lens carrier embodying an elongated shank, and means for mounting the shank for longitudinal adjustment on the guide.

4. In a machine for grinding lenses of diiferent curvatures on a single grinding wheel, a grinding wheel, means for mounting the grinding wheel for rotation about an axis, a support, a base member, pivot means mounting the base member on the support for swinging movement in a plane disposed substantially parallel to the axis of rotation of the grinding wheel, a carriage, means for mounting the carriage on the base member for right-line adjustment toward and from the pivot means, a guide mounted on the carriage for oscillating movement about an axis disposed substantially parallel to the axis of rotation of the grinding wheel, a lens carrier including a part holding a lens block in opera- JOSEPH HARRY

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