US2316109A - Apparatus for grinding optical glass - Google Patents

Description

April 1943. H. SOLODAR 2,316,109

APPARATUS FUR GRINDING OPTICAL GLASS .Filed April 14, 1942 1 I INVENTOR.

. ATTORNEY Patented Apr. 6, 1943 UNITED STATES PATENT OFFICE APPARATUS FOR GRINDING OPTICAL GLASS Harold Solodar, New York, N. Y.

Application April 14, 1942, Serial No. 438,943

3 Claims.

This invention relates generally to grinding devices and apparatus, and is more particularly directed to the provision of a grinding unit assembly, which includes a work-holder adapted to be cooperatively associated with a grinding element, for relative manipulation, in grinding a piece of work carried by the holder, in the performance of a sO-called hand operation.

While my invention possesses a wide range of utility in the performance of grinding operations in the processing of various articles, it is especially useful in performing certain grinding operations that are requisite to the production of optical lenses, and the present disclosure will be directed, more or less specifically, to this particular application thereof, as illustrative of the advantages which flow from the practicing of my invention, by means of the structure herein shown or equivalents thereof, within the scope of the appended claims. 4

As is well known, in orderto meet the existing requirements, an optical lens must have either a flat edge or a bevelled or sb-called peak edge. At present, either of these'two types of "edges may be formed only by employing a grinding mechanism designed solely for the production of the particular edge desired, so that where it is necessary to provide lenses having both types of edges, two separate machines must he installed and maintained for the purpose. Since these special machines are of a's'or'newhat complicated design, the installation and maintenance costs are more or less prohibitive, especially where the demand for one or the other type of edge ma not be consistent. Also, in utilizing either of these two special types of machines, considerable time is required in setting up or preparing the work, prior to the performance of the actual grinding operation, which is also timeconsuming, further materially increasing the cost of the ultimate product.

Therefore, it is the general object of thi inventionto reduce the cost of production of optical lenses and to this end, Iprovide a simple and efiicient mechanism for grinding the edges of such lenses, whereby the requisite grinding operation may be performed in a considerably shorter period of time, than is possible with the aforementioned existing apparatus, my mechanism being adapted to the formation of either a fiat edge or one of the bevelled or peak type, without effecting any change in the mechanism grinding or reducing operation.

More specifically, it is an important object of this invention to provide a grinding mechanism of a portable hand or power driven type, which may be readily assembled and set up for use, when and where desired, to serve a dual purpose in grinding various articles, and especially in grinding the edges of optical lenses. In attaining this objective, I employ a work-holder adapted for manual disposition in association with the abrasive element of my mechanism, for manipulation relatively thereto, to subject the work held therein to the action of such element, in response to a selected movement of the workholder on either of two intersecting axes, upon which it may be actuated; under the guidance of the hand of the operator.

My invention also contemplates a WOl'k-hOldBl adapted to function as a component of my grinding mechanism, as aforesaid, in which workclamping elements are oppositely actuatable to yieldingly engage and frictionally hold a lens or other piece of work immovable therebetween, in response to an opposite directional pivotal movement of the clamping element supporting means, under pressure applied thereto by the hand of the operator. The work holder also including means for maintaining the clamping elements in engagement with the work, during the manipulationof the holder in the grinding operation, together with means. for rotating the clamping elements and the work held thereby relatively to the abrasive element of the mechanism.

Other objects and advantages flowing from the practicing of my invention will become manifest as the description proceeds and I would have it understood that- Ireserve unto myself all right to the full range of equivalents, both in structure and in avenues of use, to which I may be entitled, under my invention in its broadest aspect.

For the purpose of this disclosure, I have elected to show a preferred embodiment of my invention, including a hand-operated type of grinder of aconventional design. Obviously, my invention may take other forms, and include an electric or other power driven grinder of any standard or other design, suitable for practicing my invention, as hereinafter set forth.

In the accompanying drawing:

Figure l is a side elevation, partly in section,

of a grinding unit, assembly, conforming to my invention, including the work-holder supported from the base of the unit, for movement relatively to the grinding element, as viewed alon the line 2--2 of Figure 2;

Figure 2 is a top plan view, partly in section, taken along the line !I of Figure 1;

Figure 3 is a sectional elevation of the rotatable work-holder support, taken on the line 3-3 of Figure 1; and

Figure 4 is a plan view, partly in section, of

the jaw end of the work-holder, taken on the,

line 4-4 of Figure 1, showing the work-engaging elements thereof.

Referring now to the drawing in detail in which like characters of reference are employed to designate similar parts in the several views, 7 indicates a grinding wheel of the conventional portable hand-operated type, embodying the usual clamping screw 8. Preferably a metal plate 9 is fixed to the base-casting o1 the grinding wheel, as by the screws ID, to function as the base-member of the grinding unit assembly, it being obvious that this plate may be superimposed upon a work-bench or table and the unit clamped thereto, by the clamping screw, in the usual manner.

Suitably supported adjacent one end of the base-member 9, as by the rod I l and cooperating securing nut I2, is a water container or tank l3, having a spigot, or tap M in proximity to the top of the abrasive element la, while a suitably formed water pan l5, containing a sponge It or other absorbent material is supported upon said base-member 9 immediately below the abrasive element, into which the water impinging upon said element may drain. The pan I may be fixed to the member 9 or detachable therefrom and, if desired, may embody an appropriate outlet for drainage purposes.

Fixed adjacent the opposite end of the base plate 9, as by the securing nut I1, is a standard 18, which is axially bored, as at, Hi, to form a bearing for the reception of the shaft 20 of the work-holder carriage 2|, which may be integral with said shaft or rigidly connected thereto in any suitable manner, said carriage preferably being adapted to abut upon the upper end of said standard for relative rotative movement, in the manipulation of the work-holder relatively to the abrasive element id, as hereinafter explained.

structurally, the work-holder corresponds gen-- erally to a conventional hand-actuatable punch, embodying opposed jaw members 22 and 23, pivotally mounted, as at 22a and 23d, within the contiguous offset ends of the respective actuating levers 24 and 25, which are shaped to provide hand- grips 24a and 25a, and are interconnected by a pin 26 for relative arcuate movement. The inner end of the jaw member 22 is connected to the lever 25 by a compression spring 21, for relative longitudinal movement beneath a guide pin 28 carried by said lever 25, the jaw member 23, likewise, being connected by a spring 29 to the lever 24, for similar movement, under guidance of the pin 30 of said latter lever. Manifestly, the movement of the levers 24 and 25, toward each other, in opposition to the springs 21 and 29, under pressure oppositely applied to the grips thereof, will efiect a concurrent like directional movement of the opposed jaw members, while the jaw members will recede from each other in the co-action of the jaw members and levers, under the influence of said springs, as the grip ends of the levers are relieved of pressure.

Each of the jaw members 22 and 23, at its outer end is provided with a laterally offset extension, as at 3| and 32, which may be integral therewith, or fixed thereto, as by the bolt 33 and the pins 34 and 35. These jaw extensions serve as supports for a pair of aligned shafts freely rotatable and axially adjustable in bearings provided in proximity to the outer ends of the respective extensions, which carry work-engaging means, whereby the work may be frictionally held for presentation to the abrasive element, in the manipulation of the Work-holder, as hereinafter described.

The shaft 36 mounted in the extension 3| is provided with a head 31, embodying a concentric annular recess 38 for the reception of a complemental rubber work-engaging pad 39, the thickness of which is greater than the depth of i i the recess, within which it is frictionally retained, so that outer face of said pad projects appreciably beyond the corresponding surface of the shaft head, as is clearly shown in Figure 4. The shaft 33, carried by the jaw extension 32, is similarly provided with a cup-like head 4|, having a work-engaging pad 42 seated therein, which is of the same diameter and thickness as its counterpart 39.

Mounted on the shaft 35, between the aforesaid head 31 and the extension 3|, are a pair of collars 43 and 48, between which is interposed a ball bearing 45, the cooperating collars and ball bearing serving as spacers and being freely rotatable uponsaid shaft, which is retained in its bearing by the collar 45, locked to the shaft by means of the set screw 46a. In the assembly of the shaft 36 in its bearing, as just described, the collar 45 is set relatively to the contiguous Wall of the extension 3! to permit of limited longitudinal movement of the shaft, for reasons which will become apparent. Similarly, the opposite shaft 46 is provided with corresponding collars 41 and 4B, coacting with a ball bearing 49, this shaft-also having limited longitudinal movement relatively to its bearing in the jaw extension 32, as predetermined by the adjustment of the locking collar 50 with respect to the collar 41, the locking collar being secured to the shaft by the set screw 59a.

From the construction thus far described, it will be evident that as the jaws 22 and 23 are urged toward each other, in response to counter pressure effective upon the grip ends of the levers 24 and .25, the concurrent movement of the extensions 3! and 32 will cause the opposed work-engaging pads, carried by the aligned shafts 36 and 4G to approach each other, while they will recede, as the pressure upon the free ends of the levers is relieved. Therefore, as-

suming that a piece of work, as an optical lens,

indicated at L is held in the fingers of the operator of the grinding unit between the normally spaced work-engaging pads, as these pads are urged toward each other they will contact with and engage the opposite surfaces of the lens in a cushioning movement, which flows from the aforementioned limited movement of the shafts 38 and 40, longitudinally of their respective bearings, and the progressive yielding of the resilient work-engaging pads, to that point in the workclamping action, in which the lens is firmly held between the pads 39 and 42. As will be obvious, the effective area of the pads 39 and 42, is slightly increased by their distortion under the compression forces and the concomitant increase in the frictionalv resistance between the pads and the surfaces of the lens upon which they abut, renders the pads and lens relatively immovable, so that the two shafts, with the supthe work-holder, as just described, the jaws of the latter are maintained in their relative positions, by engaging the looped ends 52a and 52b of a coiled compression spring 52, with the extremities of the grip ends 24a and 25a of the actuating levers 24 and 25, as shown in Figure 2, In lieu of the spring, a long bolt or threaded rod may be employed to maintaining the jaws in their work-clamping position, the grips 24a and 25a being apertured adjacent their ends for the reception of the bolt, with its head in engagement with one of the grips, while the threaded portion of the bolt extends through the aperture of the other grip, the locking of the levers in adjusted position, being accomplished bymeans of a wing nut carried upon the threaded portion of the bolt and actuatable thereon to engage the contiguous surface of the juxtaposed lever.

Following the interconnection of the levers 2 3 and 25 for maintaining the pads in engagement with the lens, as just pointed out, the WOTk-. holder may be positioned on the aforesaid horizontally rotatable carriage 2|, for arcuate movement transversely of the abrasive element la. A pin 53, carried by one of the jaw members, which extends through the opposite jaw member, for relative movement in the actuation of the levers 24 nd 25, functions to support the work-holder from the carriage 25,- the upper surface of the latter being undercut to form a semi-annular roove Zla, for the reception of said pin, the length of the carriage providing for its entry be tween the jaw members for engagement of the pin 53 therewith, when the latter members are in their ultimate positions for the performance of the grinding operations (see Figure 3). As will be noted, the groove Zia forms a bearing surface within which said pin may be readily positioned by the operator of the unit, to provide an axis for the movement of the Work-holder in a vertical plane, or in the path of rotation of the abrasive lement.

With the work-holder in bearing engagement with the carriage 2|, as just described, the edge of a lens positioned between the pads of the clamping elements, in co-axial alignment therewith, may be instantly. presented to the face of the abrasive element fa, as the jaw end of the work-holder is tilted downwardly toward the abrasive element, concurrently with the raising of the gripend of the holder, under the guiding hand of the operator. As will be manifest, if it is desired to produce a flat edge, the jaw end of the work-holder is lowered toward the abrasive element la, with the pin 53 and the carriage 2| disposed parallel to the aXis of rotation of said element, so that the edge of the lens L will be projected in the path of rotation of the revolving element for parallel contact with the face thereof, in the performance of the grinding operation, the uniform reduction of the edge to the desired profile, being accomplished in the concurrent rotation of the lens in contact with the revolving element, by means of the crank 5i. In some instances, during an operation, it may be necessary to rock the work-carrier on its fulcrum 53, to move the edge of the lens into and out of contact with the face of the abrasive element.

However, such movement is effected without permitting the holder to deviate laterally from its aforesaid. initial alignment with said element. For forming a bevelled or so-called peak edge, as the edge of the lens is projected toward the abrasive element, for contact with the face thereof, by the downward movement of the jaw end of the work-holder, the latter is simultane ously rotated on its vertical axis 20, to: the right or left, as the case may be, so that the edge of the lens will be presented to the face of the revolving element at 'an angle, instead of parallel thereto,

as when a flat edge is to be ground, to produce the required bevelled surface, the angularity of the bevel being determined by the degree of the arc through which the work-holder is rotated. Th initial position of the work-holder, of course, is maintained throughout a bevelling operation, except where a variation may be necessary to insure uniformity of the bevel, the lens, as when producing a flat edge, being rotated relatively to the revolving abrasive element by the crank 5!, as described. In the formation of a double bevel or peak edge, it will be obvious that the rotative movement of the holder to the right, for example, will angularly, project the left side of the edge of the lens in the path of the revolving abrasive element for bevelling. When this surface has been formed, the opposite side of the lens edge may be subjected to the abrasive action of the element la, in a corresponding movement of the work-holder to the left. Any irregularities that may be present in the peak of the edge, upon the completion of the two bevelling operations, may be readily removed by touching up the edge, as required in a subsequent operation, which may involve the tilting of the work-holder back and forthon its fulcrum 53.

Upon completion of a grinding operation, it will be evident that the work may be instantly removed from the work-holder, simply by releasing the spring 52 from engagement with one of the grips to permit the operator to control the actualtion of the levers 24 and 25, under the influence of the springs 2'! and 29, in the movement of the pads 39 and 42 out of engagement with the work.

As will be apparent from thestructure described, I have provided a. simple, durable and highly efficient grinding mechanism of the dual purpose type, whereby lenses and other articles in the processing of which the practicing of my invention may prove advantageous, maybe more expeditiously produced, with a resulting saving in manufacturing costs. The portability and compactness of my mechanism contribute ma-- terially to its utility, in which connection it may be pointed out that while I have shown and described my mechanism as including a hand-operated grinder, a treadle operated grinder or one driven electrically or otherwise may be employed in the assembly of the unit.

While I have described my mechanism more or less specifically, with reference to the embodiment herein shown, it will be understood that various changes may be made in details of structure and in their mode of assembly and cooperation, without departing from the spirit and scope of my invention. For instance, the pads 39 and 42 may be of any suitable material, other than rubber and may take other forms than herein shown and described, it being essential, of course, that where'the work comprises a frangible, as glass, that the means for engaging such work and retaining it in the work-holder be of a nature, or their movement into work-engaging position be so controlled that damage to the work will not result. Also, the assembly of the work-holder, apart from the work-engaging means, may be changed to meet production or other requirementsin the practicing of my invention, which is broadly directed to the provision of a portable dualpurpose grinding mechanism assembly, ca-

' pable of functioning as herein described.

I claim:

1. A work-holde for manually presenting a piece of work. to a revolving tool, for the performance of an operation thereon, including a pair of levers pivotally connected between their respective ends for'relative opposite movement, an extension pivoted to each of said levers and slidably connected to the opposite lever for concurrentopposite directional actuation, said extensions being provided with aligned bearings, a shaft freely rotatable in each of said bearings, the opposed ends of said shafts being of enlarged diameter,'resilient work-engaging means carried by the ends of said shafts, means connecting said shafts inwardly of said work-engaging means for movement with said extensions toward :and from each other, in response to opposite directi'onal movements of said levers, whereby the actuation of said levers toward each other will produce a concurrent opposite movement of said extensions to urge said work-engaging means into contact with a piece of work positioned therebetween for ultimate engagement thereby in a continuation of such movement to render the work immovable with respect to said work-engaging means, and yieldable means connecting said levers for maintaining said work-engaging means in effective engagement with the work.

' 2. A work-holder for manipulating a piece of Work with respect to a grinding element, for the performance of a predetermined grinding operation; including a pair of levers hingedlyr connected for relative opposite movement adjacent their ends, means forming extensions of said levers hinged to said levers at their latter ends for concurrent opposite directional movement, each of said latter means being slidably connected to the opposite lever and provided with aligned bearings, a shaft freely rotatable within each of said bearings, resilient work-engaging means carried by said shafts oppositely disposed in normally spaced relation, means connecting said shafts to said extensions, independently of said bearings, for movement with said extensions toward and from each other, in response to corresponding directional movements of said levers,

whereby the actuation of the free, ends of said levers toward each other will produceaconcurrent hinged and sliding movement of said extensions relative to said levers to urge said workengaging means into contact with a piece of work disposed therebetween, for ultimate engagement thereby in the completion of such lever move-- ment, to render the work immovable relatively to the work-engaging means oppositely engaged therewith, means for rotating said work-engaging means and the engaged work as a unit, and yieldable means connectable to the free ends of said levers on completion: of the movement of the free ends of said levers toward eachother for maintaining said work-engaging means in positive engagement with the work for rotative movement therewith.

3. A dual purpose grinding mechanism, including a'rotatable abrasive element, means for supporting a work-holder for manipulation in juxtaposition to the face o'f-said element, said supporting means comprising a work-holder carriage embodying a bearing surface having its axis disposed parallel to the axis of said abrasive element, means for mounting said carriage for rotatable movement in a vertical-plane in spaced relation to the face of said element, a workholder, means carried by said work-holder for clampingly engaging apiece of work, means on said work-holder formed for registration with said bearing surface to render said work-holder connectable to said carriage for relative oscillation on the axis of said bearing surface in a single manual movement of said work-holder toward said carriage to superpose the bearing surface-engaging means of said workholder upon said work-holder carriage-bearing surface, whereby said work-holder may be instantly p0- sitioned upon said carriage for relative oscillation in a vertical plane on the axis of said bearing surface to project a piece of work engaged by said clamping means into parallel contact with the face of said abrasive element and in a horizontal plane in the conjoint arcuate movement of the connected work-holder and carriage on the axis of the carriage mounting, to present a piece of work for contact with the face of said abrasive element at a relative angle; as determined, by the extent of the horizontal arcuate movement of the work-holder relative to the face of said element, said work-holder being instantly detachable from said carriage by lifting the workholder from said carriage.

' HAROLD SOLODAR,

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