US1480438A - Machine for truing lens-grinding laps - Google Patents

Description

Jan. 8 1924. 1 1,480,438

I J. J. GUILFQYLE ET AL.

MACHINE FOR TRUING LENS GRINDING LAPS Filed June 15 1922 3 Sheets-Sheet l J I v i i (mantel-s Jan. 8, 1924. 1,4801438 V J. J. GUIL FQYLE ET AL MACHINE FOR TRUING I JENS GRINDING LAPS Filed June 15, 1922 '5 Sheets-Sheet 8,

$1 Hue nto-as ua/nwa d ya Za Zr eeiar z 0-5 Bela/ambit lzerhz Patented Jan. 8, 1924.

UNITED STATES PATENT OFFICE.

JOHN J. GUILFOYLE, FREDERICK w. WILKES, AND BENJAMIN E. BEIER'TON, 0F

BIRMINGHAM, ALABAMA.

MACHINE FOR TRUIN'G Application filed June 15,

To all whom it may concern:

Be it known that we, JoHN J. GUILFOYLE, FREDERICK WV. WILKES, and BENJAMIN E. BRIERTON, citizens of the United States, residing at Birmingham, in the county of Jefferson and State of Alabama, have invented new and useful Improvements in Machines for Truing Lens-Grinding Laps, of which the following is a specification.

The present invention relates to the initial truingor re-truingoflaps and similar tools having curved surfaces, and more particu larly to those of the kind used in grinding ophthalmic 01' other lenses.

Lenses, and particularly ophthalmic lenses are usually produced by grinding, using tools, commonly called laps, which are composed generally of metal having surfaces of various curvatures conforming with the respective curvatures of the surfaces to be given the finished lenses. These laps not only require the initial production of true surfaces thereon corresponding accurately with the surfaces of the lenses to be produced, but they become untrue after use, owing to the uneven wear thereon, and hence they become unfit for further use, unless they can be re-trued accurately and economically.

The primary object of this invention is to v provide a machine which is capable ofinexpensively and accurately truing or re-truing laps of this character and similar tools havving curved surfaces, the machine embodying means for accommodating it to the various curvatures of the surfaces of the laps. both convex and concave, and it also embodies means for accommodating it to laps having surfaces of different radii on different meridians, or to a surface having a plane or rectilinear surface on a meridian thereof. The machine is thus rendered capable of truing all of the great variety of laps ordinarily used in the grinding of ophthalmic lenses, including those having spherical,

cylindrical and toric surfaces, both convex and concave.

To these and other ends, the invention consists in certain improvements and combinations and arrangements of parts, all as will be hereinafter more fully described, the features of novelty being pointed'out particularly in the claims at the end of'the speci-' fication. I

LENS-GRINDING Lars.

1922. Serial No. 568,653.

In the accompanying drawings Figure 1 is a top plan view of a lap truing machine constructed in accordance with the preferred embodiment of the invention;

Figure 2 represents an elevation of the machine shown in Figure 1, looking from below in that figure;

Figure 3 is a collective view showing in detail and in detached relation the parts composing the too-l holder;

Figure 4 is a detail view, partly in section, illustrating the tool holder in operative relation with the lap holder;

Figures 5 and 6 are detail views of driving elements of the machine;

Figure 7 is a detail view, partly in section, showing one of the eccentric driving members;

Figure 8 is a detail view, partly in section, of the means for guiding the tool holder during its movements in one direction; and

Figure 9 is an elevation of the guiding means shown in Figure 8.

Similar parts are designated by the same reference characters in the several views.

The present invention provides a machine which is capable of use generally for forming surfaces of various kinds on different articles,'although it is particularly adapted for use in the truing and re-trui-ng of the surfaces of lens grinding laps. The preferred embodiment of the invention is shown in the accompanying drawings and will be hereinafter described in detail. It is'to be understood, however, that the invention is not restricted to the precise construction shown, but that equivalent constructions are contemplated and these -will be included within the scope of the claims.

In the present instance, the machine comprises a suitable base 1 which may be in the form'xof a table and which serves as a support for the various operative parts of the machine. The machine comprises a driv= ing shaft 2 having a pulley 3 or other suitable means for receiving power from a suit able source, this shaft being journall'ed in bearings 4 on the'base and havin a crank 5 fixed to one end and provided wit a crank pin 6 and having a worm 7 s'plined on and is driven from the shaft 2 by a worm wheel.

10 which is fixed on the shaft 8 and meshes with the worm 7 on the shaft 2. During the operation of the machine, the shaft 2 has a to-and-fro endwise movement in its bearings 4 and in order to enable the worm 7 to maintain a correct operative relation with the worm wheel 10, notwithstanding the endwise movement of this shaft 2, the worm is splined on the shaft 2, as previously stated, and it is held immovably in an endwise direction by a yoke 11 which is supported in fixed position by a post or standard'12. By this construction, the worm 7 will maintain a driving connect-ion with the shaft 2 but the latter can shift axially or endwise within the worm, the worm, however, being held immovably in an endwise or axial direction, and hence it will maintain a correct operative relation with the worm wheel 10 fixed on the shaft 8. The driving pulley 3 for the shaft 2 may be splined thereon, as shown, so that this pulley may remain in alinement with its driving belt and pulley, or any other suitable means may be provided for driving the endwise shiftable shaft 2. The shaft 8 drives a pair of eccentrics 13 which are fixed thereon in the same anular relation and the rods 14, which are criven by these eccentrics, are operatively connected to the opposite ends of a sleeve 15, through which a tool driving bar 16 reciprocates. The sleeve 15 and the tool driving bar 16, therein are, when the machine is correctly adjusted, in exact parallelism with the shaft 8, and to enable this adjustment to be obtained or the parts to be re-adjusted, if necessary, the eccentric rods 14 may be constructed of telescopic or otherwise adjustable sections which maybe secured in properly adjusted relation by the set screws 17.

The tool driving bar 16 receives a gradual lateral movement through the action of the eccentrics 13, while this tool driving bar is making endwise reciprocatory strokes, these reciprocatory strokes being obtained, in the construction shown, from the crank 5, the pin 6 of which is operatively connected to the bar 16 by the connecting rod 18. The tool driving bar 16 during its lateral movements, under theaction of the eccentrics 13, maintains its operative relation with the crank 5 which reciprocates this bar, this be ing permitted by the endwise travel of the shaft 2 in its bearings and the splined connection of the worm wheel 7 and, if necessary. the driving pulley 3, with the shaft 2. The tool drivingbar 16 is accurately guided during its lateral movement, so that it will move in a true rectilinear direction. For this purpose, the ends of the sleeve 15 in which the bar 16 is mounted is provided with guides 19 which are fixed on the base and closely fit the ends of the sleeve 15, which latter acts as a cross head, it thus guiding the tool driving bar 16 vertically during its lateral shifting movements, and these guides also support the tool driving bar so that its endwise reciprocatory movements, under the action of the crank, will be in a true rectilinear direction. t

The tool holder is mounted on the tool driving bar 16, the latter being preferably formed with a squared or other angular portion 20 to fit snugly into a socket 21 formed on the member 22 of the tool holder, and immovably secured by a set screw 23. The tool holder comprises generally relatively movable members, one of which (the member 22 in the present instance) is secured to the tool driving bar 16, and the other member 24 of which carries the operating tool.

Preferably and as shown, the member 22 of r the tool holder is channelled or grooved at its opposite sides, as at 25,.to closely but slidingly receive the arms 26 of the tool holder member 24, the latter being substantially yoke-shape in form to enable its arms 26 to straddle the member 22. A roller 27 the purpose of which will be hereinafter 'described, is journalled between the arms 26 of the tool holder member 24, it being mounted on a shaft 28, the ends of which may be secured in the arms 26. The member 22 is slotted at its opposite sides, as at 29, to permit the roller shaft 28 to extend through and to shift vertically in this member of the tool holder, and the latter is also formed with a slot 30 which is transverse to'the slots 29 and serves to accommodate the roller 27, which latter is movable vertically in this slot during relative vertical movements between the tool holder members 22 and '24, The lower ends of the slots 29 are preferably closed, as shown, to prevent detachment of the member 24 from the member 22, unless the roller shaft 28 is removed, accidental detachment of the parts of the tool holderbeing thus avoided. A spring 31 is provided which acts to extend or project the member 24 downwardly or away from the member 22, this spring being shown as bearing on a cross piece 32 which is detachably fitted across the tops of the arms 26 of the tool holder member 24.

The tool, which may be in the nature of a file where laps, such as those usually composed of metal are to be trued or re-trued, has a universal connection with the tool holder, whereby the surface of the tool is enabled to maintain a position at a normal to the surface undergoing truing, although the toolwill be caused to shift in the appropriate directions relatively to the lap to enable the surface thereof to be properly trued. Preferably and as shown, the tool, which may be in the form of a flexible file 33 which is sprung or held in proper form by a tool socket 34. is connected to the tool holder by fitting the socket 34 detachably into a grip 35, a key 36 adapted to pass through registering holes 37 and 38 in the members 34 and 35 being suitable for adjustably holding these parts in proper relation. The grip 35 is formed with a pair of ears 39 in which a pair of pivot screws 40 are fitted and these pivot screws fit into recesses 41 in the opposite sides of-a block 42 and midway of its length. The lower end of the tool holder member 24 is also formed with a pair of downwardly projecting ears in which are fitted a pair of pivot screws 44, and the inner ends of these pivot screws engage in recesses 45 in the respective ends of the block 42. By this, or an equivalent construction, the tool is so connected to the tool holder that it may maintain a position at a normal to the surface of the lap undergoing truing, with respect to all meridians of such surface.

The lap, one of which is shown in .position and designated X in Figure 4, is mounted on a suitable lap holder 46. This lap holder may consist of a stud having a key 47 to fit into the key-way in the shank of the lap and thus insure correct positioning of the lap thereon. A spring 48 is also provided which acts to force the lap upwardly or in a direction toward the tool and in opposition to the action of the spring 31 which forces the tool downwardly or against the surface of the lap.

It is to be understood that a number of tool holders 34 will be provided having files or tool surfaces of different radii corresponding with the radii to be given the laps on one meridian, it being merely necessary to place a tool in the grip 35, the surface of which conforms with the surface on one meridian of the lap to be treated. If the lap is to have a plane or rectilinear surface on one T meridian, as is the case with laps used for grinding cylinder lenses, thefile or tool selectedw'ilLbe-straight, whereas, if the lap ".i's't'o have a convex curvature of-a given radine on such fm'eridian, a '"w'ill be used havinga corresponding radius, q'anu'ir the lap is to be given a concave curva concave tool 33 ture on such meridian of a given radius, the

tool selected will be convex and willhave a corresponding radius. In any case, it will a be understood that the length "of the file or "mun The'spri'ng48 during the trump. ac-

" tion 'presses the lap upwardly" and thus maintains the requisite pressurebetween it and the tool. The path of movement of the,

" file or'toolv in a direction transverse to its length isggove'r'ned according to the; curva ture'to'be given the lap on' its other merid jan; or itsmeridian at right angles to the "meridian first mentionedan d which is g'ovcrned by the shape or curvature of the file or tool. The path of the tool in this latter or transverse direction is governed by the relative vertical movements taking place between the tool holder sections 22 and 24, as controlled by a template, one of these templates being provided for each lap curvature to be produced. Preferably and as shown in the present instance, a carriage 49 is provided to receive and support the template 50 in proper position, the carriage being mounted or supported to travel in a path in parallelism with the longitudinal reciprocations of the tool driving bar 16, the carriage in the construction shown being mounted on a. pair of rails 51, which latter maybe suitably mounted or supported on the bed or table 1. The end members of the carriage may be formed with recesses 52 to removably receive and hold the respective ends of the template and the'side members 53 of the carriage lie in close contact with the opposite sides of the member 24 of the tool holder, so that the carriage will reciprocate in exact synchronism with the reciprocating movements of the tool driving bar, although the tool holder member 24 may move vertically between the side vmembers 53 of the carriage,-as controlled by the template during the lateral movement of the tool driving bar under the action of the eccentrics. The roller 27 of the tool holder bears on the template mounted in the carriage and the roller is held in contact with the template by I the action of the spring 31. It will be understood that any template appropriate to the nature and radius of the curvature of the lap to betreated can be interchangeably mounted in the carriage 49. i 7

, Theoperation of the machine to true or retrue the surface of a lap is substantially as follows: A. file or tool33 is placedl in the tool socket 34 which is straight when the surface, of the latter is to be plane or recti linear on one meridan, or is concave or convex on the proper radius when the surface 'of the lapis to be convex or concave on such meridian, and a template. 50 is mounted in the carriage which has a convex or concave curvature of a radius correspond ing to the radius of the lapfo'n a meridian at right 'angles to the meridian first men tioned. The lapf i's mounted onthelap 'holder, as showiiinFigure 4fand with the 'fil'e or tool incon'tactw th the lap and maintained under'appropriate pressure, due to the opposing forces of the springs 31 and 48, the machine may bestarte'd intooperation, this involving concurrent rotation of the shafts, 2"and 8. The shaft 2 reciprocates the tool. driving bar 16 through the action of the cranl rlfi. and the file or tool is thereby caused to reciprocate longitudinallyback and forth across the face ofthelap, theluniversalcon;

'nectio'n between the tool'and "tool holder eniii going truing or re-trueing. Preferably, the

gearing or driving connection betweenthe shafts 2 and 8 is such that this gradual 3 transverse movement of the tool will occur at each longitudinal stroke of the tool, the eccentrics 13 which cause the lateral movement of the tool making one revolution to say longitudinal strokes of the tool. This operation continues until the face of the lap has been completely trued, the range of transverse movement of the tool being suflicient to cover the entire face of the lap and the curvature of the face of the lap in the direction transverse to the length of the file or tool is an exact reproduction of the curvature of the template used, the shape or curvature of the face of the lap on its other diameter being made to agree exactly with the shape or curvature of the file or tool used. Ordinarily, spherical surfaces are produced by using a file and template of the same curvature, the radius of which agress with that of the surface to be trued or produced; toric surfaces are produced by using a file or tool having a radius of curvature conforming with that of the toric surface on one meridian and a template hav ing a radius of curvature conforming with that of the surface on its other meridian, and cylinder surfaces are produced by using a straight file or tool and a template having a radius of curvature conforming with that of the cylinder surface to be produced. The machine, therefore, is capable of being easily and quickly adapted to true or re-true all of the kinds and degrees of surfaces commonly used for laps, such as those employed in grinding lenses and especially ophthalmic lenses.

We claim as our invention l. A machine for truing lensgrinding laps comprising. in combination, a lap-support, means for reciprocating a tool across the face of a lap on said support, said tool being shaped to conform with the shape to be given the face of the lap on one diameter thereof, means for moving the tool in a direction transverse to its direction of reciprocation, and means governing the path of the latter movement of the tool in conformity with the curvature I to be given the face of the lap on a diameter laps comprising, in combination, a lap-slip port, means for reciproating a tool across the face of a lap on said support, means for moving the tool in a direction transverse to the direction of said reciprocating movement, and a templatemounted to reciprocate in unison with said tool and operativefto govern the path of the tool during said transverse movement and thereby determine the shape of the faceof the lap on a corresponding diameter. 7

3. A machine for truing lens-grinding laps comprising, in combination, a lap-support, means for guiding a tool to reciprocate in one direction across the face of a'lap on said support, and means for concurrently guiding the tool to move in a path transverse to said reciprocatory movement and in conformity with the curvature to be given the face of the lap in such direction. 4. A machine for truing lens-grinding laps comprising, in combination, a lap-support, means for reciprocating a-tool' crosswise on the face of a lap on said support, means for moving the tool longitudinally oi the face of the lap, and a template having a shape conforming with the shape to be given the face of the lap on its longitudinal dimension and cooperativewith the tool during its crosswise and longitudinal movements to govern the path of its lognitudinal movement.

5. A machine for truing lens-grinding laps comprising, in combination, a laprsupport, means for reciprocating a tool in one direction and for shifting the tool in a direction transverse thereto, means for guiding the tool to move rectilinearly during its reciprocatory movements, and means for guiding the tool to move in a curved path during its relatively transverse shifting movement.

6. A machine for truing lens-grinding laps comprising, in combination, a lap-support, means for moving a tool in two directions in right-angular relation with respect to the surface of a lap on said support, means for guiding the tool to move rectilinearly with respect to one of said movements, and means for guiding the tool in a curved path with respect to the other of said movements.

7. In a machine for truing lens-grinding laps comprising, in combination, a lap-support, a tool holder embodying a tool member and an actuating member, said members being relatively movable in directions toward and for shifting said member in a relatively V transverse direction, a template. carriage movable in synchronism with the recipro catory strokes of the tool holder, and a template on said carriage member of the.

tool holder to govern the path of the tool during its relatively transverse shifting movements.

8. In a machine for truing lens-grinding laps comprising, in combination, a lap-support, a tool holder embodying a tool-carrying member having a universal joint for connecting a tool thereto, and an actuating member, said members being relatively movable in a direction toward and from the face of a lap on said support, means for reciproeating said actuating member in one direction and for shifting said member in a rela tively transverse direction, a carriage movable in synchronism and parallelism with the reciprocatory movements of said actuating member and adapted to hold a template, and means on said tool carrying member cooperative with the template to guide the tool in an arcuate path with respect to said relatively transverse shifting movement of the tool.

9. A machine for truing lens-grinding laps comprising, in combination, a lap support, a tool holder embodying a tool actuating member and a tool carrying member, said members being movable relatively to each other in directions toward and from the face of a lap on said support, means for reciprocating said actuating member rectilinearly, means for concurrently shifting the actuating member in a relatively transverse direction, a carriage reciprocable in synchronism and parallelism with said actuating member and adapted to hold a template, means carried by said tool holding member and cooperative with the template to guide the tool with respect to its relatively transverse movement, means acting on the tool carrying member to maintain it in operative relation with the template, and means associated with the lap-support for maintaining the lap in working relation with the tool.

10. A machine for truing lens-grinding laps comprising, in combination, means for yieldingly supporting a lap, means for concurrently reciprocating a tool in one direc tion and shifting it in a relatively transverse direction across the face of a lap on said support, means for yieldingly forcing the tool toward the face of the lap, and means for guiding the tool in a curved path with respect to its relatively transverse shifting movement.

In testimony whereof we have hereunto set our hands in presence of two subscribing witnesses.

J OHN J. GUILFOYLE. FREDERICK W. WILKES. BENJAMIN E. BRIERTON. Witnesses:

B. FRANK Yon, F. J. BIRKLEY.

Images