US2548418A

US2548418A - Surfacing machine

Info

Publication number: US2548418A
Application number: US792668A
Authority: US
Inventors: Daniel P Bernheim; William A Gunning
Original assignee: American Optical Corp
Current assignee: American Optical Corp
Priority date: 1947-12-19
Filing date: 1947-12-19
Publication date: 1951-04-10
Anticipated expiration: 1968-04-10

Description

Aprifl 19511 D. P. BERNHEIM ET AL. 29 9 SURFACING MACHINE Filed Dec. 19, 1947 5 Sheets-Sheet l INVENTORS DANIEL P. @ERNHHM WLUAM A. GUNNlNG ATTOR NEY April' 10, 1951 D. P. BERNHEIM ET AL 2,548,418

SURFACING MACHINE Filed Dec. 19, 1947 5 Sheets-Sheet 2 JNVENTORS no DAN\E.L. P. BERNHE\M 131% 4- W\L LIAN\ A. suNmNe ATTORNEY p 1951 D. P. BERNHEIM ET AL. 2,

' SURFACING MACHINE Filed Dec. 19, 1947 5 Shegs-Sheet 3 m tiSe m INVENTORS DANlEL. P. EERNHE\M 64- WILLJAM A. sumqme ATTORNEY BY 'z 5 April 10, 19511 D. P. BERNHEIM ETAL v SURFACING MACHINE Filed Dec. 19, 1947 5 Sheets-Sheet '4 I57 2 v F" INVENTORS DANQ; P. BERNH& \M WILLIAM A. GUNNlNG I ATTOIZN EV April 10, 1951 D. P. BERNHEIM ET AL 2,543,418

SURFACING MACHINE d is ZOI

M 8 INVENTORS Z'Z $v DAN\E.\ P. I5ERNHEIM W|LL|AM A- GUNN\NG ATTORNE.

Patented Apr. 10, 1951 SURFACING MACHINE Daniel P. Bernheim and William A. Gunning,

Southbridge, Mass., assignors to American ptical Company, Southbridge, Mass., a voluntary association of Massachusetts Application December 19, 1947, Serial No. 792,668

17 Claims.

This invention relates to surfacing machines and has particular reference to an improved apparatus for producing lenses and similar articles having surfaces of single or compound curvatures and to an improved process for producing said lenses and similar articles.

One of the principal objects of the invention is to provide improved means for surfacing articles such as lenses to various surface formations including single and compound curvatures, and an improved process of abrading whereby the resultant surfaces will have a relatively smooth and fine texture.

Another object is to provide a surfacing machine of the above character embodying means for feeding a cup-type abrading tool transversely of an article to be abraded-such as a lens, to abrade a surface on said article of a single or compound curvature, said surface curvature or curvatures depending upon the angle at which said abrading tool is disposed relative to the article and the radius of curvature about which theabrading tool is moved transversely of the article.

Another object of the invention is to provide a surfacing machine of the above character having means for controlling the rate of transverse movement of the abrading tool relative to the article to be abraded whereby the tool will be fed transversely of said article at a speed substantially equal to the rate of removal of portions of the surface of said article by the abrading surface of said tool.

Another object is to provide asurfacing ma- 'chine of the above character which will gen-' erate surface shapes of negative forms of various different single or compound curvatures.

Another object is to provide a surfacing machine of the above character with a cup or ringtype abrading tool so supported that it may be disposed at various different angles relative to the article to be abraded with substantially no change of the positional relation of the tool with respect to the article.

Another object is to provide a surfacing machine of the above character having its abrading tool and article to be abraded confined within a housing, in combination with improved means for directing a lubricant to the engaging surfaces of said tool and article, with thehousing confining the lubricant and material removed from the article within said housing and pre-' venting said material and lubricant from gaining access to other working parts of the machine.

Another object is to provide an. improved vacuum system to draw the mist formed by contact of the lubricant with the engaging surfaces of the tool and article from the housing to prevent the mist from gaining access to other parts of the machine or to the area outside the machine.

Another object is to provide a floating feed arrangement for moving the abrading tool transversely of the article to be abraded.

Another object is to provide a feed arrangement for moving the abrading tool transversely of the article to be abraded which embodies means for causing the tool to be floatingly moved in said transverse direction in combination with variable cushioning means acting in opposition to said first named means.

Another object is to provide a feed arrangement for moving the abrading tool transversely of the article to be abraded, which feed arrangement embodies a weight suspended upon a cord connected with the tool support for imparting said transverse movement, in combination with adjustable pneumatic means also connected with said tool support in such a manner as to resist the gravital pull of the weight and which also functions as shock absorbingv or cushioning means.

Another object is to provide a machine of the above character with means for adjusting the abrading tool relative to the article to be abraded and the article relative to the tool, with said adjustment means embodying an arrangem nt, whereby the major adjustments may be quickly and easily performed, and more accurate. and finer adjustments may be subsequently performed. 1

A further object is to provide a rotating lap together with means for adjusting the lap both radially and angularly with respect to a pivot post and a diameter running through said pivot post respectively.

A still further object is to provide means for supporting the article which may be adjusted radially of the pivot post whereby said article may be brought into contact with the rotating lap and the amount of material to be removedfrom said article may be controlled.

A still further object is to provide yielding means for swinging said lap or tool on said pivot post and to provide means for controlling the rate of said swinging movement.

A further object is to support the tool in operative relation with the work whereby the tool is free to permit manual manipulation in a direction transversely of the work.

Another object is to provide separate work supporting means which may be initially adjusted so as to assume an accurate positional relation and alignment with the curve generating mechanism of the tool when supported in operative position relative to said tool.

Another object is to provide manually operable means by which the depth of out or amount of material removed during the transverse move ment of the tool relative to the work may be posi tively controlled.

Another object is to provide adjustable means for locating the efiective abrading position of the tool in accurate position with respect to the curve generating mechanism of the tool whereby-any shift of position due to change in diameter of the tool may be compensated for; thereby permitting tools of various different diameters to be used and also affording means for obtaining the optimum degree of accuracy of curve generation.

Still'anotherobjectis toprovide means for the preliminarypositioning or gauging of an article to be abraded'prior to locating saidarticle in. abrading position in the machine, said means being adapted to position an article while a previously positioned article is being abraded.

Another-object is the'provision of a surfacing machine utilizing a magnetic chuckfor effi= ciently retainingan' article to be abraded while the abrading operation is being performed.

Further objects are to provide in a manner as hereinafter set forth a surfacing machine which is'coinparatively simple in its construction, din able,- thoroughly efiicient in its use, and readily" Set up and adjusted for abrading articles having various surface characteristics.-

Other objects and advantages of the invention Will become apparent from the following description taken in connection with the accompanying drawings, in which:

Fig. 1 is a perspective view of a surfacing machine embodying the present invention;

Fig. 2 is afragmentary-perspective view of the movable head illustrating particularly the mechanism for-imparting a'transverse rotating movement'thereof during operation of the machine;

Fig. 3 is a fragmentary viewpartly in section. taken vertically through the head and associated mechanism-and including a portion of t-he machine bed;

Fig. 4-is' a fragmentary sectional'viewoi the feedcontrol'parts within the forward portion of the bed;

Figs-5&5 afragmentaiy'sectional view taken ou on line HH of Fig. 3;

Fig. 12 is a perspective View of-the gauge used for aligning anabrading tool in the machine; and Fig. 13 is a fragmentaryside View illustrating the tool aligning operation;

Prior to the present'invention it has been the usual practice to reduce lens blanks or articles of a similar nature to substantially the finished thickness desired just prior to performing the final polishing or other finishing operations of the surface thereon by hand abrading operations or by slow inefficient mechanical methods. Hand abrading methods were not only slow but also undesirable from a standpoint of cost and such operations depended greatly upon the accuracy and skill of the operator. Prior mechanical abrading methods, while a considerable improvement over handmethods, have been slow due in great part to the time required between abrading operations to position an article to be abraded and the abrading tool with respect to one another whereby the article will be abraded to have the surface characteristics desired. One method for mechanically' grinding and polishing the surfaces of optical lenses and like articles employs what is known as the lap system. This is in effect a curve transference; the lap transferring to the article that is being ground, a curvature controgeneric to that of the lap. The: grinding of these articles byv laps, particularly the rough grinding before the smoothing and polishing-operations take place, is slow due to the factof the restricted number of articles in some instances that can be worked on at one time by a single lap. This lap system also requires an exceedingly large: number of tools, it being necessary in'fact' to provide a separate tool to each curvature which is tobaplaced on the article thus requiring a very large investment in tools forthe-manufacture of articles such as optical lenses.

Prior mechanical methods employing the gen erative system, that is, the system whereby. the curve that is formed on the article to be abraded is not transferred as by a lap but is generated as the grinding proceeds, also have sometimes proved to be ineflicient because of the somewhat compli'cated nature of the devices used toadjusthave the desired surface characteristics.

The present invention eliminates the above undesirable features through the provision of asingle cup-type abrading tool and associated mechanismwhereby surfaces of single orcompound curvatures may be quickly and easily generated by said tool by improved mechanical means, and the process may be speeded by the provision of means for gaugingan article. to be abraded while asimilar previously gauged:artlcle is in theprocessof being abraded, together with simple. and" efiicient'adjusting means forming a part of the machine whereby thearticle andthe abrading tool may be mechanically positioned with relation to one another without depending upon the skill and accuracy of the operator. .With

the present invention a single tool is employed. to

' parts throughout the several views the invention comprises a machine for generating or surfacing articles with minus curvatures and comprises a hollow machine base I5 supporting a bed 16 provided on its upper surface with spaced tracks or guideways I! on which is slidably located the machine head mechanism [8, the head mechanism I8 being provided with a supporting plate I9 having spaced tracks 26 on its under side adapted to interfit with the tracks l1, the engaging surfaces of the tracks I1 and 26 being machined so that the head [8 may be moved on the tracks I1 with ease and accuracy. The means for slidably moving the head on the tracks l1 includes a manually operable handle member 2| rotatably mounted by its shaft 22 in a bracket 23 (Fig. 3) formed on the inside of the end wall of the bed I6, the shaft 22 carrying a gear wheel 24 adapted to mesh with the gear wheel 25 positioned on the end of a transversely disposed threaded shaft 26. A gear box 21 is suitably positioned on the end of the bed 16 to cover the

gear Wheels

24 and 25. The threaded shaft 26 has a bearing in the bracket 23 near the end carrying the gear 25 and is adapted to threadably engage a protruding portion 28 of a tubular depending member 29 formed integral with the under side of the supporting plate member [9 (Fig. Thus by manual rotation of the handle 2I the entire head mechanism l3 can be moved longitudinally of the bed I6 on the tracks I1. A scale 36 graduated in millimeters is fixedly secured to the edge of the front track I1 on the bed l6 and has its reading edge aligned with an index mark on the reading edge of a scale 3! graduated in diopters which scale in turn has its reading edge aligned with an index mark on the millimeter scale, the dioptic scale being secured to the outer edge of the forward track 28 on the supporting plate l9. By this means the extent of the sliding movement of the head mechanism I8 on the bed I6 may be determined.

The entire head mechanism with the exception of the plate l9 maybe rotated about a given axis on a pivot post 32 which has its upper end positioned in a vertical opening in the base plate 33 and held from rotation therein by a key member 34. The post 32 is headed at its upper end and has mounted thereover in its lower regions the inner race 35 of a roller bearing unit 36, the post 32 being rotatable within a vertical opening 38 in the tubular depending member 29 formed on the supporting plate I9. The roller bearing unit 35 has its outer race 31 located'on the inner wall 01' an enlarged opening 39 in the tubular member 29 and concentric with the opening 38, and thereby provides means whereby the base plate 33 and the head mechanism mounted thereon may more easily and unrestrainedly rotate. A washer-like retaining member 49 is secured by means such as screws 4| over the end of the depending member 29 and with the head of the post 32 serves to prevent vertical displacement of the post.

The base plate 33 is formed with downwardly extending spaced inner and

outer flanges

42 and 43 respectively, the inner flanges 42 being adapted to engage the inner race 44 of a roller bearing unit 45, the outer race 46 of the bearing unit 45 being adapted to snugly reside within an upwardly extending flange 41 formed on the supporting plate l9. This roller bearing unit 45 serves to minimize friction between the base plate 33 and supporting plate l9 when the base plate 33 is rotated.

The base plate 33 and parts of the head mechanism I 8 mounted thereon may be rotated in one direction by means of the gravital pull of a weight 48 (Fig. 8) carried by a cord 49, the

weight 48 being disposed within the machine base I5 and adapted to slidably engage an inclined motion reducing plate member 59, the plate member 59 being secured at its upper and lower ends to portions of the base [5. The cord 49 is connected at one end to the weight 48 and extends upwardly through an opening 5| in the top of the base'I5, and passes over a pulley 52 rotatably mounted by stud 53 on a bracket 54 depending from an overlapping housing member 54a fixedly located on the bed I6. The cord 49 is adapted to reside within a circumferential groove provided in the outer surface of flange 43 of the base plate 33 and has its other end fixedly secured by suitable means to the base plate 33. 7

Thus the cord 49 will respond to the gravital pull of the weight 43 and the head mechanism I8 is free to swing about the center of the pivot post 32. A suitably disposed handle member 55 may be used to manually return the head mechanism to such a position that upon release of the handle 55 the weight 48 will cause the head mechanism to again be rotated. This handle also aifords means whereby the head may be manually swung on the pivot post with the pulley'suspension of the weight permitting free manual manipulation. This permits the tool to be manually fed transversely of the work.

The gravital pull of the weight 48 is resisted by means of a'suitable motion dampening device such as the dashpot 56. This dashpot 55 is of a conventional design employing a piston adapted to oscillate within a fluid filled chamber, the oscillating thereof being controlled by suitable means such as the valve control 51, the plunger rod 58 of the dashpot device 56 having its outer end connected to a toothed rack 59, the rack 59 being adapted to mesh with a gear 60 suitably secured as by pin 6I-to the lower end of the pivot post 32. A ring member 62 is adjustably secured by studs 63 to the outer surface of the lower end of the depending member 29 formed on supporting plate I9 and serves to carry a downwardly extending roller carrying stud 64, the stud 64 being secured to the ring member 62 by means such as pin 65 and having mounted thereover a roller 68, the roller 66being adapted to engage the rear surfaceof the rack 59 to maintain the rack in mesh engagement with the gear 69. By proper adjustment of the valve control 51 the resistance of the dashpot device 56 may be regulated and the rate of swing of the base plate 33 and'the entire assembly mounted thereon may be yieldably controlled. This provides a motion dampening arrangement which; not only functions in opposition to the gravital pull of the weight 48 but also acts as a shock absorbing means. It is to be understod that the controlling of the rate of swing of-the base plate 33 can be controlled by the dashpot device 56 to retard the rate of swingfrom' a fast swing caused by the weight 48 being unrestrainedly permitted to cause rotation of the base plate 33 to a rate of swing so small that the eye cannot observe the rotation of the base plate. It is also to be understood that the dashpot 56 is rigidly mounted in a bracket '61 secured to the under surface of the supporting plate l9 by bolts 68 and thus is adapted to move with the plate l9 longitudinally of the bed I6. The bed l6 has an opening 69 in its end wall through which the dashpot 56 may pass, as shown in Fig. 4, and a cover 19 is hinged as by the hinge pin 1! to the bed IE to conceal and protest the device.

The base plate 33 may be prevented from rotating by means of a friction lock 12 comprising a cam member 13 (Fig. 2) rotatably mounted by means of stud 14 On the supporting plate l9 adjacent the base plate 33 and adapted to be manually rotated by a handle 15 attached thereto to a? frictionally engage the: outer surface of the-base plate 33 to render it immobile.

Tliehead -mechanismmounted on the base plate 33 may be moved longitudinally with re spect to the plate-33 by means of an operating shaft 16 which is adapted to extend through an opening in one end of a hollow table i! formed integralwiththe-upper surface of the base plate 33. The shaft '16 is provided with a threaded portion 18. which is adapted to be entirely positioned within'the table 1'! and an end portion I9 of smaller. diameter than the threaded portionl8, theshaft being rotatably mounted. in a bushing 8i located'in the-opening in the end of thetablell; the rotation thereof being manually controlled by a handle 8|; The bushing 88 is formedwith a flanged portion 82 adapted to engage the inner surface of the end Wall of'the table 11 anda stop plate 83- is secured to the shaftportion is by a pin 84, the flange 82 and stop plate 83' cooperating to prevent longitudinal displacement of the shaft 75.

The head mechanism mountedon the table l? includes a slidable base member 35 having tracks 86 formed longitudinally'on its lower surface, the tracks 85 being adapted'to slidingly engage tracks 81 formed on the upper surface of the table H. An operating member 85 is secured to the under side of the base member 85, being provided with an upwardly projecting portion 89 which is positioned within a vertical opening in the base member 35 and held immovably in place by a retaining plate iii) and screw 9|. The member 88 has a longitudinally threadedopening for reception of the threaded portion'l' of the operating shaft it. Thus, by operation of handle 8| rotation of shaft '56 will cause the'base member 85 and the parts of the head mechanism-mounted thereon to slide longitudinally of the table T! on the tracks 86 and Y87, the engaging surfaces of the tracks 86 and 8? being machined similar to tracks I1 and 26 to provide ease and accuracy of movement of the sliding member. A diopter scale 92 is secured to the edge of the forward track 86 and a millimeter scale 93 is secured to the edge of the table 11 and are adapted to be read similar to the scales-3| and 3B. The scales 92 and'53 are similar to the scales 3! and 3G'respectively except that the scales 92. and 33 are graduated reversely to the graduations on scales 3| and 30.

A quadrant-shaped plate 9d is movably mounted on the upper surface of the base menu-- bar 85. andis adapted to pivot about an axis formed by a pivot stud 9,5.- The pivot stud 951s insertedin a vertical opening in the quadrantshaped plate 95, the opening in plate Q 2 having anenlarged lowerportion for reception of a loci: nut- 96, the lock nut 86 being threadedly mounted over theend of the pivot stud 95 and having bifurcated portions 97 securedly connected by screw 98 in such a manner that when SCI'GWBB' is tightened the bifurcated portions 87 will tend to abut and thus will lock the lock nut 96.0n the end of stud 55. The quadrant-shaped plate 94 is provided near one end with a vertical opening in which is located a bushing tithe pivot stud 95 being disposed within the bushing 99. A vertical opening is provided in the-pivot stud.95 for, insertion of an alignment member as will, be hereinafter described, the alignment member to be used in setting up the machine. Since-it is important that the opening Hill as wellas the stud 95 should-be protected from possible damage a cap member lfll is threadedly inbase member 85.

sorted-in an enlarged upper portion of the ver.'

sponding tc'a smilar adjacent surface portion H13 formed'on the under side of the quadrant-shaped. plate 9%. This provides'constantly'accurate posi=- tioning of the-plate-Sd on the base member 85,

the base member 85' also being providedlwithra graduated scale lfi i'so that the amount'of' rotary.

movement of the-quadranvshaped plate-Mewith respect to the base member 35 may be indicated- The base member 85 has-a flangedportionlili formed on its outer end and-the plate gdiis pro-- vided with a. pair of spaced bifurcations I06 (Figs. 3 and 11). A movable block Hll'ispesi tioned between the bifurcations Hit and isadapted to reside on the upper surface of the the under surface of the flanged portion 185 of:

base member 85; A-clamp i Hiisprovided with a vertical shaft l l I adapted'to extend downwardly through concentric openings inthe-cover plate 188, block it? and flanged portion H35. and-isthreadediy inserted in the clip 189.. Phe shaft 5 ii is provided with a peripheral flange land.

a handle 5 I 3 whereby upon manualmanipulation of the handle N3 the shaft Hican be made to turn to tighten the. clip. iflflaga-inst theunder surfaceof the flanged portion lcdof the base.

sired as indicated by the scale 9 2. The clamp.

H 3 may thenbe againmanipulated to lock the block iii? immovable against theupper surface of the base member '85.

To obtain the finer adjustment there is provided an operating shaft Ht horizontally disposed and adapted to extend. through both bifurcations iflti of the quadrant-shaped plate'ildj'ithe shaft being maintained in position by retaining washers H5 secured to the shaft iidj adjacent the outer surfaces of the bifurcations me as by pins H6. A worm gear. Ill is fixedly locatedon the shaft IM between the bifurcations E68" and is adapted to mesh withthreads formed on the outer surface of the block ml, and a knurled knob l l 8 is located on the end ofthe shaft l M for manual operation of-the device. Thus, since the block It? is immovably positioned on thebase member 35, when the knob i l 8 is turned to rotate. the worm gear H? the action of'. the gear. HT against the block Nil will causethe bifurcations Hid-and consequently the quadrant-shaped plate 94 a well as the portions of the head mechanism mounted thereon to move slightly about the axis formed by the pivot stud 95, thereby providing the final adjustment of the position of the quadrant-shaped plate 94 with respect to the base member 85.

The upper surface of the quadrant-shaped plate carries an integral horizontal set of tracks or guideways H9 which are adapted to slidably supportengaging tracks I28 formed on the under side of a motor support I 2| A rotat- A cover plate lfiB coversrthe, upper surface of the bifurcations JGSandblock it? and a clip N39 is adapted to reside againstdepending portion I23 on the front of the motor support I2I, the shaft extending between the tracks H9 and carrying on its forward end a knurled operating knob I24 and having its rear end rotatably disposed in an upwardly extending portion I25 of the plate 94. Thus, by rotation of the knob I24 and shaft I22 the motor support I2I can be made to slide on tracks I IS in a manner similar to the movement of the supporting plate I9 on the bed tracks I1. The amount of the movement of the motor support I2I on tracks H9 is indicated by adjoining scales I26 and I21 located on the outer surface of one of the tracks I20 and adjacent surface of the plate 94 respectively.

The motor support I2I is formed with a hollow portion I28 in which is adapted to project a downward extension I29 formed integral with the under side of a motor base I30. The motor base I30 is provided with a longitudinal machined portion I3I which is adapted to slidably reside in a groove machined in the upper surface of the motor support I2I. An adjusting screw I32 is rotatably mounted through a portion of the motor support I2I and has a portion thereof threaded I into an opening in the extension I29, the screw I32 having a slotted head at its outer end and being provided adjacent the inner surface of the wall of the support I2I with a retaining washer I33 connected thereto by a pin I34 to prevent lateral displacement thereof. Thus, by rotation of the screw I32 by a screw-driver or similar means the motor base I30 and mechanism mounted thereon can be made to slide in the groove in the motor support I2 I. Threaded bores are provided in the motor support I2! for reception of locking bolts I35, the bolts I35 being adapted to extend downwardly through slotted openings I36 in the motor base I30 and into the bores so that when the motor base I30 has been positioned as desired by the adjusting screw I32 the bolts I35 may be tightened to maintain the base I30 in its set position on the support I2I.

Fixedly located on the motor base I30 is a motor I31 which is suitably connected to a source of current (not shown) and controlled by a switch device I38 disposed on the machine housing in any suitable location easily accessible to the machine operator such as shown in Fig. 1. The motor I31 drives a shaftI39 to which a cupped or ring-type abrading tool I40 is secured. The tool I40 is preferably of a diamond impregnated or charged type and has its abrading portion I4I formed with a curved cross-sectional shape.

The housing 54a on the bed I6 has fixedly secured thereto by bolts I42 a head I43 which is adapted to carry the work to be abraded. The head I43 is provided with a pair of spaced upwardly extending supporting arms I44 between whichis carried a chuck I45, the chuck I45 being of any suitable conventional type but preferably of a magnetic type. The chuck I45 has supporting members I41 secured to each side thereof by bolts I46, the members I41 being provided with flanges I48, the flanges I48 being adapted to extend over the top surfaces of the arms I44 and to be secured thereto by means of bolts I49. To assist in supporting the chuck I45 a supporting plate I50 is provided between the lower surface of the chuck I45 and the top of the head I43, the plate I50 being secured to the head I43 by bolts il. The chuck I45 has formed in the top surface thereof a longitudinal V-groove I52 having its opposed surfaces precision machined so that a work-carrying spindle I53 when disposed in the groove will extend in a true horizontal direction and when removed from the groove the same spindle, or another similar spindle, may be replaced in the groove without "requiring" any realigning operations .to locate the spindle in its original position. The chuck I45 illustrated in the drawings is of the permanent magnetic type and is provided with an operating lever I54 so that when the lever I54 is turned to the "on position the magnetic field of the chuck will attract the spindle I53 in such a manner that the spindle will be fixedly retained in the V-groove I52 until such a time as the lever I54 is turned to the off position to change the field of the chuck I45 and thereby permitting the spindle to be removed. A suitable cover plate I55 may be secured as by screws I56 over the ends of the chuck I45 and supporting plate I50 for appearance.

An adjustment device I51 (Fig. 6) similar to a micrometer is located in the upper end of a bracket I58 secured to the edge of the head I43 adjacent the chuck I45 by bolts I59. The bracket I58 is provided with an enlarged supporting portion I60 having a horizontal bore in which is adjustably located a bushing I6 I, the bushing being threaded on its internal surface and adapted to receive the threaded portion I62 of an operating member I63. The bushing is held in adjusted position by a set screw I6Ia and provides adjustment to compensate for wear and to enable a zero setting to be made. The outer end of the operating member I63 is of smaller diameter than the threaded portion I62 and has a knurled operating knob I64 secured thereto by a pin I65, the knob being spaced from the end of the bracket I58 and bushing I6I and having a peripheral flange portion I66 adapted to eXtened over the end of the supporting portion I60 of the bracket I58, the flange portion I66 having micrometer markings I61 therearound (Fig. 1) cooperating with markings I66 on the supporting portion I60. The other end of the operating member I63 is also of smaller diameter than the threaded portion I62 and carries in its extreme end ahardened contact member I69, the member I69 being immovably positioned in the end of the member I63 (Fig. 6).

A jig I88 is used in setting up the work holding device, the jig being disposed in some easily accessible location such as by attaching it to the front of the machine bed I6 as shown in Fig. l. The jig I88 is shaped to support the spindle I53 and includes spaced supporting arms I89 having V-grooves therein and an upwardly extending arm I90 at one end thereof, with a corresponding arm I9I at its opposite end. The arm I9I carries an adjustable pin member I92 which is threadedly connected to the upright arm I9I and is adapted to be locked in adjusted position by a set screw I92a. This pin member is engaged by the article to be abraded such as the lens blank I63, and the adjustment thereof is to enable a standard gauge length to be set up and to provide means to compensate for wear of the parts.

The spindle I53 is comprised of a tubular body I10 having a plug I1I fixedly secured in the forward end thereof by means such as pin I12 (Fig. 6). The plug IN is formed with a tapered shank portion I13 and has a threaded portion I14 about midway thereof and adjacent the end of the body I10, the threaded portion carrying a knurled nut I15. A bushing I16 is provided in the end of the body I10, being held therein by a eases is adapted to be engaged by one end of a coil sp ng I8I which is inserted in the tubular body I19 between the piston I80 and the plug I1I.

An article such as a lens blank I83 which is to be abraded is adhesively secured to a block IM by meansof a layer of pitch or other suitable adhesive I85 (Figs. 9 and 10). The block I84 is secured to an adapted I86 as by adjusting screws I81, the adapter I89 being provided with a rearwardly extending portion which is adapted to be fitted snugly over the tapered shank portion I13 of the plug I1I in the spindle I53. The knurled nut I15 on the threaded portion I14 of plug I1I is for the purpose of easily removing an adapter I95 from the tapered shank portion I13.

When the spindle is properly seated in the V-grooves of the jig I98 it is to be understood that the distance between the end of the contact member I99, when the micrometer adjusting device IE! is set at zero, and the abrading surface of the tool is known. Therefore, by adjusting the adjustable pin member I92 the distance between the pin member I92 and the jig arm I99 can be made to exactly correspond to the distance between the contact member I69 and the abrading surface of the tool. After locking the pin member I92 by set screw I92a, the spindle I53 carrying the lens blank I83is located in the V-grooves of the jig I88 with the surface to be abraded of the blank I83 in abutment with the end of the adjusting pin member I92. With the spindle in this position the spring I8I will tend to force the piston I99 and plunger rod I19outwardly of the body I19 in a direction toward the jig arm I90 and into abutment therewith. A set screw I82 inserted through the body I19 and bushing I19 may then be manually turned by its upper portion into engagement with the plunger rod I18 to retain the rod in its set position.

In positioning an article to be abraded such as the lens blank I83 in abrading position in the machine, the blank is attached as described to the spindle and the spindle gauged in the jig I88. The properly gauged spindle with the lens blank I93 attached is then inserted in the V-grooves I52 of the demagnetized chuck I45 with the end of the plunger rod I18 in abutment against the end of the friction pin I 69 of the micrometer adjusting device I51 which device has been previously set at zero on the markings I51 and I58. With the spindle in this position the operating lever I54 can be turned to the on" position causing the'ch'uck to attract the spindle thereto with sufficient force to prevent the spindle from becoming displaced during an abrading operation. By this means the lens blank will be properly and accurately supported during the abrading thereof. It will also be understood that since the combined spindle and lens blank unit has been previously gauged in the jig I88 to compensate for the thickness of the lens blank to be abraded, the lens blank when properly seated in the V-groove of the chuck I45, and with the micrometric device set at zero, will be in alignment with the are described about the pivot post 32. It is also to be understood, however, that the micrometer adjusting device will be able to cause the spindle to slide longitudinally within the V-groove I52 when the knob I54 is manually turned. The inward movement of the operating inserted within smaller vertical bores 12 member I 93 upon turning of the knob I64 will, through the plunger rod I18, cause the entire spindle unit including the lens blank to be moved in the chuck and toward the abrading tool an amount as indicated by the scale markings I91 and I38, and controls the amount of material to be removed by the abrading tool during the abrading operation. By first having knowledge of the initial thickness of the blank, this adjustment enables the final thickness of the blank to be controlled.

In setting up and operating a surfacing machine of the preferred type, a tool I49 of the desired size is first attached to the rotor drive shaft 3., by means of a threaded bolt I93 and washer I 99 (Fig. 2) and the tool is then aligned with respect to the axis of the pivot stud 95. This is done by removing the cap member IIlI from its position covering the pivot stud 95 and inserting the gauge I95 illustrated in Fig. 12. The gauge I95 is formed with a disc-shaped body portion I95 having pin members depending therefrom, a main pin member I91 being centrally disposed with respect to the undersurface of the body portion 595 and being of such size and shape as to reside snugly within the vertical opening III!) in the pivot stud .95. One or more supplementary aligning pins I98 also depending from the under side of the body portion I 95 are adapted to be (not shown) in the pivot'stud 95 to position the gauge in such a manner that an upright I99 supported upon the upper surface of the body portion I96 will be engaged by the abrading portion of the tool 39, as shown in dotted outline in Fig. '3.

By'turning the adjusting screw I32, the motor I31 and tool I 49 may be moved longitudinally until the tool is in desired contact with the gauge upright I99.

The same gauge I95 may be used to align the tool I49 horizontally by inserting the gauge at an angle ninety degrees from the position shown in Fig. 3, positioning the gauge in such a manner that the center of the cutting portion of the tool may be aligned with the edge of the upright I99, as shown in Fig. 13. To horizontally align the tool with the edge of the upright I99, the shaft I2-2 may be rotated to cause the motor support I2! to slide horizontally on the quadrant-shaped plate 94.

It is to be understood that the center 290 of the curved face of the tool I40 should be adjusted so as to be coaxial with the axis of the pivot stud 95 (Figs. 9 and 10). The longitudinal adjustment therefor provides means for compensating for wear of the surface of the cutting edge of the tool and this feature should be checked periodically sothat as the cutting edge of the tool I49 is worn down this wearing action may be compensated for so that articles such as optical lenses will be surfaced accurately. After aligning the tool the gauge I95 may be removed and the cap member I9I replaced.

The abrading tool I49 may be'then adjusted to the desired distance from the axis of the pivot post 32 to control the arc of the'curve-to be generated in the horizontal meridian of the article to be surfaced. This is accomplished by first operating the handle 2| to cause the supporting plate I9 to be slidably moved on the bed I9 to an extent as indicated by the scales 39 and -3I. For example, if a six diopter curve is to be generated on the surface of an article such as a lens blank I83, the supporting plate I9 will be 7 slidably moved on bed I6 to a position where the scales. 30 and iii will indicate that a curve of six diopters will be generated. Then the handle 8I may be operated to slidably move the base member 85 and the parts of the head mechanism mounted thereon longitudinally of the table I! on the

tracks

86 and 81 to a position where the

scales

92 and 93 will render an indication similar to the scales 30 and 3|. This latter adjustment is a compensating adjustment which initially enables the tool to be adjusted in a direction away from the work an amount sufficient to permit the scale settings to be made on the scales 30 and 3|. The tool may then be moved toward the work and to its final desired position as determined by-the scales-92 and 93..

It is particularly pointed out that the curve. which is generated will be of the concave or negative form and the radius of curvature is dependent upon the distance at which the cutting edge of the tool I40 is adjusted with respect to the longitudinal axis of the pivot post 32. This arrangement, therefore, provides for various differently controlled curves to be formed in the horizontal meridian.

The curve generated in the vertical meridian of the lens blank or. other article to be surfaced is controlled by the tilting of the tool I40 relative to the position which the longitudinal axis or plane of the blank assumes when supported in operative relation with respect to the tool. This is accomplished by loosening the clamp I I0 and adjusting the quadrant-shaped plate 94 upon the base member 85 about the axis of the pivot stud 95. After adjusting the plate 94 to the approximate desired position as indicated by the scale I04, the clamp H0 is tightened and the knob II8 isthen operated to obtain the finer adjustment necessary to position the quadrant-shaped plate 94 as desired.

If the curve to be generated on the lens blank or other article I83 is to be a single spherical type curve, the tool I40 is angled so as to generate a curve in the vertical meridian of'the blank which corresponds in radius to the curve generated by the swing of thetool in a horizontal direction about the center of the pivot post 32. The two curves, therefore, will be of the same radius and will thereby generate a single spherical curve. If the surface is to have a compound curvature, then the adjustments are made so as to introduce the different radii of curvatures desired in the respective vertical and horizontal meridians.

After the above-mentioned adjustments have been made, the article or blank I83 carried by the spindle I53 may be inserted in the chuck I45, the spindle having been previously adjusted in the jig I88 as described so that the particular thickness of the lens blank I83 to be surfaced may be accommodated. It will be understood that in inserting the spindle I53 in the chuck I45, the rod I'I8 will be placed in abutment with the contact member I69, the micrometer adjustment having been previously set at zero. At this time current may be applied to magneti'zethe chuck I so that the spindle I53 will be securely held in the V-groove I52 thereof. The'amount of material to be removed from the lens blank may be then controlled by operation of the micrometer adjusting device I51 to cause the operating member I53 and contact member I69 to urge the spindle I53 toward the surfacing tool I40, the amount of material to be removed being determined by the micrometer markings I61 and I68. It is to be understood that the initial thickness of the blank has been determined and that the final desired thickness is known.

Prior to making the fine adjustment for determining the amount of the material to be removed from the blank, the tool I40 is swung in a sidewise direction about the axis of the pivot post 32 to a position out of engagement with the blank. It may be held in this position by means of the cam locking device I2 pivotally connected to the supporting plate I9 and adapted to frictionally engage the edge of the base plate 33.

After adjusting the micrometer device I51 and releasing the locking device I2 the tool I40 may then. befed transversely of the article or blank I83 by means of the gravital pull of the Weight 40 carried by the cord 49 which is secured to the base plate 33, the dashpot dampening device 56 being adjusted to regulate the rate of swing of the plate 33 and the entire assembly disposed thereon. This dashpot arrangement not only functions in opposition to the gravital pull of the weight 40 but also acts as a shock absorbing means to prevent vibratory movement of the tool I40 relative to the lens blank I83 during the abrading operation, and the entire feed may be adjusted so as to substantially keep pace with the rate of removal of the cutting tool, thereby enabling the forming of a very finely abraded surface having a relatively smooth and fine texture. This yieldable control is 'a strongffeature in the cutting of the lens blank as heretofore a positive advance of the tool often caused breakage or chipping of the blank and also a rough finished surface. As the most uniform glass never cuts at exactly the same rate of speed, the yieldable control drive of the tool across the face of the article or lens blank is a positive feature in producing a true and relatively smooth out.

The above arrangement also permits the tool to be manually swung in a direction transversely of the tool either for prelocating the tool relative to the work or for making an initial cut or'the entire abrading cycle may, if desired, be manually performed.

A lubricant or coolant is fed onto the engaging portions of the tool and article being surfaced from a supply tank 20I disposed in the machine base I5 by means of a pump 202, the pump 202 being of any conventional type adapted to force liquid from the tank 20I through a pipe line (not shown) to the conduit 203 (Fig. 2) where it will be expelled onto the tool and article. The tool and article to be surfaced, as shown in Figs. 1 and 2, have a housing 204 surrounding the same to confine the fiow of the lubricant and material removed from the article within the housing, and for preventing the lubricant from being splashed or otherwise gaining access to other working parts of the machine. The housing 204 has a base portion 205 and a top portion 205, the top portion 200 being hinged to the base portion 205 so as to be swung vertically upon hinges 201. Within the housing 204 are splash guards 208 which are secured to the inner walls of the base portion 205 of the housing and positioned in relatively intimate or closed relation about the said tool and article to confine thelubricant to the desired engaging surfaces of the tool and article.

The lubricant will be drawn by gravity out of the base portion 205 of the housing 204 and expelled into the tank 20I from the conduit 209.

It may be desired to use a vacuum system to draw the mist formed by thelubricant upon engaging the rotating tool and article being abradedfrom within the housing 204, such a vacuum system 2,6.48,41.&

being referred to in. Fig. 8 by; the numeral 210 and includes a. motor 2H. which is adapted to. set up a suction to draw the mist from the interior of; the housing 2M into the conduit 2 and to. expel it into the lubricant in the tank 20L From the foregoing description, it will be seen that simple, emcient and economical means have been provided for accomplishing all of the objects and advantages of the invention. By providing the improved features described, it can be seen that the present inventionis not only a. considerable improyement over hand surfacing operations but also. an improvement. over prior mechanical devices by the provision of means for presetting an article to. be surfaced before installing it in abrading position thus considerably speeding up the surfacing operations of such articles as optical lenses and also. by the provision of simple and easily operated adjusting means for positioning an abradingtool with respect to the article to be abraded, and means for magnetically holding an article. to. be. surfaced in abrading position in the machine.

Although a. variable field type magnetic chuck 5 has; been disclosed herein as a preferred type of chuck any other known type of magnetic or mechanical chuck may be employed as, for example, in the latter instance a chuck embodying a V-block in combination with suitable clamping mechanism may be employed.

While certain novel features of the invention have been shown and described and are pointed out. in the annexed claims, it will be understood that various. omissions, substitutions and changes in the forms and details of the device illustrated and in its operation may be made by those skilled in the art without departing from the spirit of the invention.

We claim:

1. A surfacing machine comprising a base having a work supporting head fixedly secured adjacent one end thereof and having a slid'eway extending in a direction longitudinally thereof, a slide member on said slideway movable toward and away from said work supporting head, a rotatable portion pivotally secured to said slide member for movement about an axis disposed normally to the direction in which said slide member is movable and having a second slideway thereon, a second slide member mounted on said second slideway movable toward and away from said axis. and having a tool supporting head pivotaliy attached thereto for movement about a second axis disposed substantially parallel tov said first a cupped type abrading tool having its effectiye. abrading surface in the form of an arc with its center coaxial with said second axis whereby the tool may be moved about said second axis as a center to different angular positions, means carried by said tool supporting head for rotating said tool and adjustment means carried by said work supporting head for moving an article to be abraded into alignment with the effective abrading portion of the tool and for controlling the depth of the abrading action of the. tool on. the article, whereby the tool may be swung about the first axis as a center to cause the effective abrading portion of the tool during the rotation thereof to move transversely of the article and cause the shape of the resulting abradedsurface on said article, to have a curvature in. One meridian thereof controlled by the adjusted angle of the tool about the second axis and in the major meridian thereof controlled by the arc of swing of the tOOl about said first axis.

2. A surfacing machine comprising a base hay ing a supporting means thereon for support,- ing Work in a, predetermined position and having a slideway to ne side of said work supporting means, a slide member mounted on said slideway' for movement toward and away from said work pivot means on said slidemember, a rotatable supporting member having a second slideway thereon and being piv otally connected tosaid pivot means, a scale and indicator means carried by said first slide said first pivot in an are controlled by ad jzustment of the tool; relative. to the axis, of said first. pivot, said work supporting means including a work holder and. an adjustable contact member for engaging the work holder and moving said work holder toward the tool to. control the amountof. material to be removed from the work.

by the tool scale and indicator means associated therewith for, determining the position of adjust,- ment of the work holder and the amount of removal. the relation of the tool to the work will; permit.

3'. In a device Of: the, character described means for retainin a work holder on a work supporting head and for supportin an article to be carried by said work holder to be abraded; by an abrading tool supported in adjacent operative relation with said work supporting head, said work supporting head having an adjustable contact memher and having means for controlling and indieating the extent of adjustment of. said contact member, said work holder having means for sup-- porting an article to be abraded adjacent one end thereof and having an adjustable portion. adjacent its opposed end adapted to engage the adjustable contact member of said head whenv located in operative position in said head, the distance between said contact member and the effective abrading portion of the tool being a determinable distance when the contact member is set; at zero position and the distance between the outer end of the adjustable portion of the work holder and the exposed surface of the articleto be abraded in the use of the device being, controlled so as to be substantially equal to said determinable distance.

4. In a, device of the character described, the, combination of a rotatable cupped abrading tool, means for angling said, tool relative to the work to be abraded, means for feeding said angled toolin an arcuate path about a given axis and transversely of the work along a meridian substantially normal to the angling of the tool, means for moving said axis toward and away from the work to vary the curvature formed on the surface of the work by the abrading tool, means for ad justably supportin the. work comprising a chuck having a v-groove therein, a work carrying spindle member positioned insaid V-groove to carry said work in a horizontal plane. with respect to the abrading. tool, and micrometrio l 7 means for advancing said work toward said tool in accordance with the amount of material to be removed from the surface thereof.

5.- In a surfacing machine of the character described, the combination of a rotatable abrading'tool, supporting means for carrying an article for engagement with the tool comprising a chuck having a V-groove formed therein, independent article-carrying means positioned in said V- groove comprising a holding member adapted to carry said article in a horizontal plane with respect to said abrading tool, and having adjustable contact means, and feed means for engaging said contact means and advancing said article toward said tool in accordance with the amount of material to be removed from the surface thereof.

6. In a surfacing machine, the combination of a work supporting head, a tool supporting head carrying an abrading tool for location adjacent said-work supporting head, a chuck fixedly supported on said work supporting head, a longitudinally adjustable spindle positioned in said chuck, said spindle having one end portion adapted to carry said article and its opposed end portion adjustable toward and away from said first portion to vary the length of the spindle, and microfrom the axis of said table, together with a second supporting portion mounted on said first supthereon, and adjustable means for supporting the tool with its surface in abrading relation with the surface of the work to be abraded, said ad-- justable supporting means including a table rotatable about an axis disposed'substantially parallel to the general plane ofsaid surface of the work to be-abraded, said table being adjustmetric means carried by said work supporting head and having an adjustable contact portion for contacting the opposed end portion of the spindle and advancing said spindle and article carried by the first end portion thereof toward said abrading tool whereby the surface of said article may be positioned relative to the tool so as to be abraded to depths as governed by said micrometric means.

7. A surfacing machine comprising the combination of a tool supporting head and a work supporting head, said work supporting head having a V-groove therein, a spindle member seatable in said groove for adjustably carrying an article to be surfaced at one end thereof, and

feed means adapted to move said spindle and article carried thereby longitudinally in said V-groove in accordance with the amount of material to be removed from the surface of said article, said tool supporting head supporting an abrading tool adjacent the article to be surfaced and being rotatable about a given pivot, adjustment means for moving said pivot toward and away from the work and for correspondingly changing the amount of separation of the tool from said pivot, said tool supporting head having means associated therewith for angularly adjusting the abrading tool relative to the article about a second pivot lying on an axial line extending through the abrading surface of the tool, and means for yieldably feeding said angled tool transversely of the article and along an arc defined by said first pivot as a center.

8. A surface abrading machine of the character described comprising holding means for supporting work having a surface to be abraded, a rotatable tool having an abrading surface thereon, and adjustable means for supporting the tool with its surface in abrading relation with the surface of the work to be abraded, said adjustable supporting means including a table rotatable about an axis disposed substantially parallel to the general plane of said surface of the work to be abraded, said table being adjustable in a direction toward and away from said general. plane of the surface of the work to be abraded to vary the related position of said axis of the table to the work, a supporting portion mounted on said table and adjustable toward and away able in a direction toward and away from said general plane of the surface of the work to be abraded to vary the related position, of saidaxis of the table to the work, a supporting portion mounted on said table and adjustable toward and away from the axis of said table, together with a second supporting portion mounted on said first supporting portion with said second supporting portion carrying the tool and being adjustable about an axis disposed substantially parallel to the axis of the table and substantially intersecting the abrading surface of the tool, and means for rotating said table to cause the tool to traverse the surface of the-work.

10. A surface abrading machine of the character described comprising a supporting member having a seat therein, movable means mountedon the seat for supporting work having-a surface to be abraded, a rotatable tool having an abrad ing surface thereon, and adjustable means for supporting the tool with its surface in abrading relation with the surface of the work tobe abraded, said adjustable supporting means including a table rotatable about an axis disposed substantially parallel to the general plane of said surface of the work to be abraded, said table being adjustable in a direction toward and away from said general plane of the surface of the work to be abraded, so as to vary the related position of said axis of the table to the work, a supporting portion mounted on said table and adjustable toward and away from the axis of said table, together with a second supporting portion mounted on said first supporting portion with said second supporting portion carrying the tool and being adjustable about an axis disposed moved from the work by said transverse motion of the tool.

11. A surface abrading machine of the character described comprising holding means for supporting work having a surface to be abraded, a rotatable tool having an abrading surface thereon, and adjustable means for supporting the tool with its surface in abrading relation, with the surface of the work to'be abraded, said ad'- justable supporting means including a supporting member movable toward and away from the work to be abraded, pivot means on said supporting member, a rotatable member pivotally connected with saidpivot means, the axis of said pivot means being disposed substantially parallel to the general plane-of said surface of the work to be abraded, asupporting portion mounted on said-rotatable member andadjustable toward and away from the pivot means to which said rotatable member is pivotally connected, together with a second supporting portion mounted on said first supporting portion, said second supporting portion carrying the tool and means for rotating the tool with its axis of rotation substantially normal to the axisof' the pivot means, and said second supporting portion being adjustable about an axis disposed substantially parallel to the axis of the rotatable member and substantially intersecting the abrading surface of the tool.

12; In a device of the character described, the combination of an abrading tool and supporting means for maintaining work in controlled abrading relation therewith, said supporting means including a main support having a seat therein, a work holder mounted in said seat and movable along said seat toward and away from the tool, means adjacent the side of the work holder toward the tool for supporting the work to be abraded, and an adjustable contact portion adjacent the opposed side of the work holder movable toward and' away from the work holding means for varying the distance between the work to be abraded and thecontact portion of the work holder, locking means for retaining said contact portion in adjusted relation, and adjustable means having anengagement portion for engaging said contactv portion and moving the work holder along said seattoward the abrading tool to control the amount of material removable from the work by the tool, and means for locking the work holder in a given position along said seat;

13. In a device of the character described, the combination of an abrading tool and supporting means for maintaining work in controlled abrading relation therewith, said supporting means-including magnetic chuck'means having a- V-shaped longitudinal seat therein, a work holder mountable in said seat and movable toward and away from the tool, means carried by the work holder adjacent one end thereof for supporting the work to be abraded, a contact portion adjacent the opposed end and adjustment means for varying thedistancev of separationof the contact portion from the work supporting means,,and feed means for engaging said contact portion and moving the work holder bodily along said seat controllable amounts toward the abrading tool according to the amount of material desiredtto be removed from the work by the abrading action of the tool thereon said work holderbeing of a material magnetically attractable by the magnetic chuck means and means for energizing and deenergizing the magnetic chuck means so as to lock and unlock the work holder in a given position in said seat.

14. In a device of the character described, the combination of a rotatable abrading tool, supporting means for work having a surface to be abraded and-adjustablemeans for supporting the tool with its abrading surface in controlled abrading relation with the work,.saidsupporting means including amainrsupporthaving. a seat therein, a work holder. mountedin said seat and movable toward and away. from the tool, means adjacent the. side of thework holder toward the tool for supporting the workto be abraded, acontactportion adjacent its opposed end and means for varying the distance between the work to be abraded and the contact portion of the work holder, said adjustable supporting means for the rotatable tool including a table rotatable about an axis disposed substantially parallel'to the general plane of said surface of the work to be abraded, said table being adjustable in a direction toward and away from said general plane of the surface of the work to be abraded so as to vary the related position of said axis of the table to the work, a supporting portion mounted on said table and adjustable toward and away fromthe axis of said table, together with a second supporting portion mounted on said first supporting portion, with said second supporting portion carrying the tool and being adjustable about an axis disposed substantially parallel to the axis of the table and substantially intersecting the abrading surface of the tool, means for rotating said table, and means for moving the work holder along said seat of the main support toward the abrading tool to control the amount of material removable from the work by the tool during the abrading action thereof on the surface of the work.

15. In a surface abrading device of the character described, the combination of an abrading tool, a spindle having holding means adjacent one end for supporting work having a surface to be abraded, and having contact means adjacent its opposed end, said contact means being adjustable relative to the spindle for varying the distance between said contact means and the work holding means, feed means having an engagement portion for engaging said contact means of the spindle so as to permit operation of the feed means to move the spindle and work carried thereby into effective abrading relation with the abrading tool, and gauge means for indicating a standard of distance between the initial .position of the engagement portion of the feed means and the abrading tool whereby the distance between the contact means and work holding means of the spindle may be adjusted to compensate for dilierent thicknesses of work so as to permit predictable amounts of material to be removed from the work under controlof the feed means.

16. In a surface abrading device of the character described, the combination of an abrading tool, a support having a seat therein, and a removable spindle positionable in said seat, said spindle having holding means adjacent one end for supporting Work having a surface to be abraded, and having, movable contact means adjacent its opposed end, spring means for urging said contact means in a direction away from the work holding means, and locking means for maintaining said movable contact means in adjusted relation, feed means having an engagement portion'for engaging-said contact means of the spindle so as to permit operation of the feed means to move the spindle and work carried thereby into effective abrading relation with the abrading tool, and gauge means for indicating a standard of distance between the initial position of the engagement portion of the feed means and the abrading tool whereby the distance between the contact means and work holding means of the spindle may be adjusted to compensate for different thicknesses of work so as to permit predictable amounts of material to be removed from the work under control of the feed means.

17. In a surface abrading device of the character described, the combination of an abrading tool, a spindle having holding means adjacent one end for supporting work having a surface to be abraded, and having contact means adjacent its opposed end, said contact means being adjustable relative to the spindle for varying the distance between said contact means and the work holding means, feed means having an engagement portion for engaging said contact means of the spindle so as to permit operation of the feed means to move the spindle and work carried thereby into effective abrading relation with the abrading tool, and gauge means for indicating a standard of distance between the initial position of the engagement portion of the feed means and the abrading tool whereby the distance between the contact means and work holding means of the spindle may be adjusted to compensate for different thicknesses of work so as to permit predictable amounts of material to be removed from the work under control of the feed means, said gauge means comprising a seat for the spindle, a stop member adjacent one end, and an adjustable member adjacent the opposed end movable toward and 22 away from said stop member to adjustthe distance of separation of said adjustable member from the stop member according to said standard.

DANIEL P. BERNHEIM.

WILLIAM A. GUNNING.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 646,397 Bancroft et a1 Mar. 27, 1900 1,140,421 Wall et a1. May 25, 1915 1,261,765 Challet Apr. 9, 1918 1,330,558 Simmons Feb. 10, 1920 1,873,067 Stromgren Aug. 23, 1932 1,9 1,181 McCabe Mar. 14, 1933 1,985,213 Page Dec. 18, 1934 2,104,345 Holhut et al Jan. 4, 1938 2,248,263 Wilhide July 8, 1941