US2652664A - Operator-controlled grinding machine with optical comparator - Google Patents

Description

Sept. 22, 1953 J. A. ALLAN ETAL 2,652,664

OPERATOR-CONTROLLED GRINDING MACHINE WITH OPTICAL COMPARATOR Filed April 18, 1952 s Sheets-Sheet 1 Z/ A; v r Im AZ 1 I j /4 w a J Z i Y I i j I I 41" I M 5 2 6 9 h j! Jfzvezzfiizr firmed) KM a Sept. 1953 J. A. ALLAN ETAL 2,652,664

-0 ROLLED GRINDING OPERATOR ONT MACHINE WITH OPTICAL COMPARATOR Filed April 18, 1952 5 Sheets-Sheet 2 JWWJ' flliaz .M I 1&

P 2 1953 J. A. ALLAN ET AL 2,652,664

INDING MACHINE OPERATOR-CONTROLLED GR WITH OPTICAL COMPARATOR Filed April 18, 1952 5 Sheets-Sheet 3 Sept. 22, 1953 J. -A. ALLAN ETAL 2,652,664

OPERATOR- NTROLLED GRINDING MACHINE wI OPTICAL COMPARATOR Filed April 1-8, 1952 5 Sheets-Sheet 4 Sept- 22, 1953 J. A. ALLAN ET AL 2,652,664

OPERATOR-CONTROLLED GRINDING MACHINE WITH OPTICAL COMPARATOR Filed April 18, 1952 s Sheets-Sheet 5 Jizw 78f Patented Sept. 22, 1953 UNITED STATES PATENT ()FFICE 2,652,664 OPERATOR-CONTROLLED enifinilfu MA- CHINE WITH OPTICAL COMPARATOR James A. Allan Springfield, Vt and Francis (J.

Savage, Columbia, Conn, as'signors to Jones &

Lamson Machine Company, Springfield; Vt., a

"cor oration of" Vermont Application April. 18, 1952, Serial No. 283,066

4 Claims. v 1

This invention relates to machines for accurate generations of desired contours and has ior one object a provision for operator control of the feed of the tool, such. as a grinding wheel, in accordance with a desired contour and in connection with an enlarged image of such contour or of successively presented portions thereof.

A further object is to provide for indirect projection of the work contour image from a position well spaced from the contact between the grinding wheel and the work so that the grinding may be accomplished wet, thereby providing for maximum grinding speed with good conditioning. of the ground surface and avoiding formation of dry detritus or dust likely to interfere with or damage lenses or other parts of the optical system employed for projection of the contour image. v

Such indirect projection of contour image further makes possible the employment of optical control in situations such as the generation of internal surface contours where direct projection would be impossible. e e

For a complete understanding of this invention reference maybe had to the accompanying drawings in which Figure l is a somewhat diagrammatic iront elevation of a grinding machine embodying the invention.

Figure 2 is a top plan view oithe same.

Figure 3 is a left side elevation of the same,

partly broken away and in section.

Figures 4 and are detail sectional views. on lines 44 and 55, respectively, of Figure 1 Figure 6 is a-view similar to a portion of Figure 1,. but showing a modification. 7

Figure '7' is a detail sectional view on line, 1-1 of Figure 6.

Figure 81s afragmentary view showing, a portion of the proiection screen with the projected image of a reticle and tolerance circles. Y

Figure 9 is a side elevation of a wheel truingdevice in use.

Figure 10' is a detail sectional; view on line l-D--lil )f.Fig l 6 9.

Figures 11 and 12: aredetail sectional views on lines H,--H and liar-i2, rrespectively ofFig Figure 13 is a fragmentary view partly broken way and in. tion an milar to a, portion of: Figures l and 6, but; showing the grinding 01? in! ternal work.

Figure 14 is a; view similar to: Figure 1,' but: showing a further modification... 7 V

Figures 15 and 16 are detail sectional views on lines I5 -l5 and Iii-l6, respectively, of Fig ure 14.

Figure 17 is a view similar to a portion of Figure 13, but showing a further modification.

Figure 18 is a view similar to a portion of Figure- 1, but showing a modified control mechanism.

Figure 19 is a diagram of the control mecha= nisrn of Figure 1 8.

Referring first to Figure 1 of the drawings, at l is indicated a machine base having a vertical standard 2 on which a slide 4 is mounted in suitable Ways 3 for vertical motion. This slide 4, as shown, has. oppositely directed portions 5 and 6, the portion 5 bein formed as a holder for a work piece I which is to be ground in its upper face to a desired contour. This Work piece I is adj-ustably supported by the work support, and for thus purpose it is shown as resting upon a pair of independently adjustable supporting screws 8 and being clamped within a slot 9 (see Figure 2) in the work supportby means of clamp screws ill. This slide 4 is shown as provided with a nut it threaded upon a vertically arranged screw 12 journaled in the support 2 and carrying at its lower end a spiral gear 15 with which meshes a spiral gear Hiv carried by a horizontal shaft I! provided with anaetuat-ing hand wheel [8 on its forward end. The support 2 is also mounted on the bed I for horizontal motion being formed as a slide provided with a depending internallythreaded boss 20 through which passes a horizontal screw 24 carrying at one end a spiral gear 22 which mesheswi-th a spiral gear 23 on a horizontal shaft shown as arranged parallel tothe shaft I "I and having a hand wheel 25 at its forward end. I i w It will be apparent that by rotating the hand wheel l8; the carriage 4 may be raised or lowered, and by rotating the hand wheel 25, the support 2 can bemoved horizontally. Ifhus the work; support 5 is capable of being moved in either of two right a-ngularly related directions in a common plane and the work piece may be caused to traverse past a. grinding Wheel 30 in the same plane and mounted ior rotation on a spindle journaledin a supporting carriage slide 3[ which is mounted for vertical adjustment on a slideway 32. A vertically positioned adjusting screw 33 carried by the member 32-; and engaging; a suitable internally threaded n-u-t on the slide 3 I provides for vertical adjustment of the grinding wheel. The slide 3| also carries a motor 35 which is connected to rotate the grinding wheel 39 through the pulleys 36 and 31- and the connecting belt 38.

The slideway 32, as shown, is carried by a sliding carriage 4c mounted for motion horizontally transverse to the plane of motion of the work holder. It may be oscillated in this transverse plane when desired to provide a latterly fiat ground face and for this purpose it may be provided with a slot 4! (see Figure 5) in which rides a crank pin 42 on a disk 43 carried by a shaft 44 journaled in any suitable manner vertically in a supporting stand 55 carried by the bed I and mounted for adjustment toward and from the carriage support 2. The crank disk 33 may be rotated as by a motor 59] carried by the stand 45 and having on its armature a worm engaging a worm wheel 5| carried by the shaft 44.

The stand 45 may be adjusted horizontally toward and from the work holder by rotation of a hand wheel 52 carried by a horizontal shaft 53 having thereon a pinion 54 engaging the teeth of a rack bar 55 carried by the stand.

By suitable adjustment of the various parts, the grinding wheel 30 may be brought into proper relation to the work piece I and may be caused to traverse the work piece generating a desired contour, by suitable manipulation of the hand wheels i8 and 25, to keep the images on the screen in proper relation as one is caused to traverse the other. In order, however, to produce a desired contour with high accuracy, optical means are provided spaced from the engagement between the grinding wheel and the work for projecting an enlarged image of a target onto a suitable screen in cooperative relation to a reference line on the screen. Where the work piece is moved to provide the feed between the work piece and the grinding wheel, as in Figure 1, this projected target 66 may be carried by the arm 6 and have an end portion simulating the contour of the grinding wheel 30.

This target 61] is adjustably secured to the arm 6 so that its projected image may be brought into proper relation to a contour marking on the screen 6| when the grinding wheel is in corresponding relation to the work piece. -As shown best in Figure 3, the optical system comprises a lamp housing 62 and a suitable lens system comprising a condensing lens 63 the light beam from a lamp in the housing 62 being projected past the upper end of the target and being focused by a lens system so as to cast an image onto the mirror 65 which is reflected back magnified against the screen 6!. This image of the target is shown in dot and dash lines in Figure 1 on the screen in successive positions as the work piece is moved past the grinding wheel and the target image is moved along the screen. As shown in this figure, the desired contour of the work piece is shown in magnified relation on the screen by the line 61, there being lines 63 and 69 parallel thereto which are spaced therefrom proper distances to show tolerance limits. Thus as the work piece is passed beneath the grinding wheel in contact therewith and the target image is moved along the screen, the work piece and target may be raised and lowered in accordance with the contour of the line 61 so that the image of the target remains within the tolerance limit lines 68 and 69 throughout the full extent of the grinding motion. I

It will be noted that the target is spaced a substantial distance from the work piece where grinding is being effected, so that it is quite feasible to apply coolant to the grinding wheel andwork as through the pipe 10 (Figures 4 and 9) so that grinding may be accomplished at maximum speed 4 r and with the ground surface maintained in the best possible condition without overheating and without the formation of dry detritus or dust which might find its way to the lenses or other parts of the optical system, resulting in damage thereto.

Since the work piece as shown in Figures 1 and 2 is a flat plate, it is desirable to oscillate the wheel support so as to prevent the formation of a dished portion between the side faces of the work so that the grinding takes place uniformly across its full thickness. This, of course, may be accomplished by driving the motor 50.

Where the entire contour to be ground is relatively small, the magnified image of the contour can be projected on a screen of reasonable dimensions, but in cases where the contour is large, such projection would result in the requirement of a screen of excessive dimensions. In such a case a difierent form of target may be used, as illustrated, for example, in Figure 6, together with a dilferent type of image carried by the screen and to which the projected image is to be properly related during the grinding operation. As shown in Figure 6, the target, instead of being a representation of the grinding wheel contour in cross section, comprises a reticle 75 having the desired work piece contour marked thereon, as the line M. This reticle is transparent and is mounted for suitable adjustment by clamps I6 and H which engage a base member 18 which carries the reticle. Various adjusting screws 19 and 8a! may be employed to facilitate proper positioning of the contour line on the reticle with relation to the motion of the work piece during the grinding operation. With this arrangement a small part only of the contour line 14 is in the path of the projected beam of light at any one time, as shown, for example, in Figure 8, and cooperating with this projected portion of the contour line are shown three circles 85, 86, and 81, the circle being positioned intermediate between the tolerance circles 86 and 81, an arcuate portion of the circle 85 representing a magnified portion of the active contour of the grinding wheel. With this arrangement it is only necessary to so control the vertical and horizontal motions of the work holder that the portions of the contour line M successively projected on the screen remain tangent to the circle 85 or within the tolerance limits shown by the circles 86 and 81.

It is, however, unnecessary that the movable holder carry the work rather than the grinding wheel. Figure 14 shows the grinding wheel carried by the arm 5a and the work piece 1a carried by a holder 45a which may be mounted for motion transverse to the plane of the work piece between the dotted line positions of Figure 16 in order to traverse the entire thickness of the work piece by the grinding wheel in a manner similar to that shown in connection with Figure 1. The work may be oscilated laterally of the plane of motion of the wheel and the target by the crank mechanism actuated by rotation of the drive shaft 89 as shown in Figure 14. This figure also shows the use of a reticle as a target, the projected portion of the contour line of the reticle being related to a central U-shaped line 99 similar to the enlarged projected image of the wheel contour and which is positioned between the parallel tolerance lines 9| and 92. It will be understood, however, that where the work piece issmall, the reverse arrangement of target and screen image shown in Figure 1 could be em ployedthe target representing a replica. of the grinding edge of the grinding wheel, and the indication on the. screen being that of the desired contour to an enlarged scale.

. In order that. the grinding wheel may be'caused to accurately grind the work piece to the desired contour, it is important that it. be kept trued to av shape corresponding to its. representation on the screen, eitherasan enlarged projected image of the target or the. enlarged contour indication marked upon the screen. To this end a wheel truing device has beenillustrated at I66 carried by an arm, IIlI (see Figures 9 to 12) which is fulcrumed on an. axis I82 adjustably. positioned to. pass. through the. grinding wheel at I03 as shown in Figure 12, so that by rocking the truing device about its. pivot axis I02, the. grinding surface may be trued to the. desired semicylindrical contour. The pivot I02 is carried by a. block 120 which may be adjusted inwardly as the grinding wheel. wears, .a spring I06. serving to press the block I020. inwardly as far as is permitted. by the nut I05. threaded on the screw I04. Thisxtruing device may be swung out'of the way when not desired, beingxcarried by an arm I07 fulcrumed at I08 to a bracket I09 carried by the wheelcarrying. slide. so that it may be swung between theoperative position shown in Figures 9, l and 11 and the inoperative position shown in Figures 4 and 5.

The provision of a target remote from the contact between the grinding wheel and the work makes it possible also to generate contours which Qfinnotbe directly projected at the contact between the wheel and the workpiece, as, for example, internal contours. as. shown in Figure 13. In such cases the work piece 11; will be carried by a'spindle II' mounted'for rotation about an axis lying substantially in the plane of relativemotion between the grinding wheel and work holder having a suitable .chuck'II-B for supporting the Work. piece Ib and suitable means such as a motor arranged within a housing III may be employed to rotate'the'work piece. It will be understood that for such an internal contour, a corresponding internal contour will be shown on the screen.

. A further internal contoured work piece is shown in Figure 1'7 in which the work piece instead of being cylindrical is a plate. This, however, may be mounted similarly to the work piece shown in Figure 1. With this arrangement the use of circles such as 85, 86 and 88 shown in Figure 8 to represent the wheel contours is highly desirable since these will be eifective for both the upper and lower edges of the contoured work piece.

In some cases it may be desired to control the two directions of motion between the grinding wheel and the work piece to produce a desired contour by a single controlling member instead of by separate manipulation of the two hand wheels such as I8 and 25. Such an arrangement is illustrated somewhat diagrammatically in Figures 18 and 19. The horizontal movements of the target and either the work piece or the grinding wheel, depending upon which of these is'mounted to move with the target, is produced by a power mechanism shown as a hydraulic differential cylinder I having a piston I26 therein connected through a piston rod I21 to a lug I28 projecting downwardly from the carriage 2. Similarly the vertical motion of the carriage 4 may be produced by a similar differential hydraulic cylinder I30 in which a piston I3I is slidable, being connected to the vertical slide 4 through a piston rod I32. The pistonsides of both of these cylinders are connected tothe pressure line I 33 from a hydraulic pump I34 (Figure I9) which takes its supply from a tank I35. A valve I36 controls the supply and discharge of fluid from the head end of the cylinder I25, and a valve I31 similarly controls the supply and discharge from the head end of the cylinder I 30 as through the pipes I 40, MI, and the pistons I42 and I43 of these valves are connected through the rods I44 and I45 and: the pivoted links I46 and I4! with a control lever I48 pivoted at I49 eccentric to the connection [50 of the links Md and I 41 thereto. By angular adjustment of the control arm I48 about its pivot I49 the relative sizes of the valve openings to the head ends of the two hydraulic cylinders may be adjusted rela, tively, to thereby adjust the amounts of fluid entering these head ends, and by turning this control member I48, the relative rates of motion vertically and horizontally may be adjusted and regulated in accordance with the contour which it is desired to cut by the grinding wheel the Work piece.

By moving the control member I48 to aditferent angular position, the. supply to the. pipes 546 and I 4| may be shut. off, whereupon the pres.- sures exerted on the inner; faces of the pistons will return these pistons to the. head ends .ot the cylinders, the target. and the part' movable: there.- with then being in starting position. As shown in Figure 18, this member I48 may be connected to a hand wheel I60 by which. its angular positioning may be facilitated and a. pointer Ii6I thereon may aid in showing the position of adjustment for any given slope of the cut.

From the foregoing description of certain embodiments of this invention it will be evident to those skilled in the art that further various changes and modifications may be made withou departing from its spirit. or scope.

We claim:

1. In combination, a work support, a wheel support, a rotary grinding wheel carried. by said grinding wheel support, means for rotating said grinding wheel, means mounting one of said supports for motion in a plane in either or both of a pair of angularly related directions to cause said grinding wheel to generate a contour on a Work piece carried by said work support, means supplying coolant to said wheel and work piece, a target remote from the engagement between said wheel and work and connected to said movable support to partake of the movement of said movable support, a screen, an optical system arranged to project a magnified image of at least a portion of said target onto said screen transverse to said plane, said screen having an image thereon of the same scale as said target image, power-operated means for moving said support and target in each of said angularly related directions, and a common control means operatively connected to both said power means and actuable to control both of said power means to move said movable support and target in selectable relative rates in each of said directions.

2. In combination, a work support, a grinding wheel support, a rotary grinding wheel carried by said grinding wheel support, means for rotating said grinding wheel, means mounting one of said supports for motion in a plane in either or both. of a pair of angularly related directions to cause said grinding wheel to generate a contour on a Work piece carried by said work support, means supplying coolant to said wheel and work piece, a target remote from the engagement between said wheel and work and connected to said movable support to partake of the movement of said movable support, a screen, an optical system arranged to project a magnified image of at least a portion of said target onto said screen transverse to said plane, said screen having an image thereon of the same scale as said target image, a pair of fluid pressure motors connected to said movable support and target each arranged to move said support and target in one of said angularly related directions, a control valve for each of tively connected to said valves to actuate said said motors, and a single actuator for said valves mounted for angular motion about a center and operatively connected to said valves to actuate said valves selectively and simultaneously control the directions and rate of motions of said fluid pressure motors.

3. In comibnation, a work support, a grinding wheel support, a rotary grinding wheel carried by said grinding wheel support, means for rotating said grinding wheel, means mounting one of said supports for motion in a plane in either or both of a pair of angularly related directions to cause said grinding wheel to generate a contour on a work piece carried by said work support, means supplying coolant to said wheel and work piece, a target remote from the engagement between said wheel and work and connected to said movable support to partake of the movement of said movable support, a screen, an optical system arranged to project a magnified image of at least a portion of said target onto said screen transverse to said plane, said screen having an image thereon of the same scale as said target image, and means for moving said movable support in said angularly related directions in a manner to cause said target image to trace said screen image and thereby control the work contour generated by said wheel, said work support having a work-carrying spindle mounted for ro- 4. In combination, a work support, a grinding wheel support, a rotary grindingwheel carried by said grinding wheel suport, means for rotating said grinding wheel, means mounting one ofsaid supports for motion in a plane in eitheror both of a pair of angularly related directions to cause said grinding wheel to generate a contour on a work piece carried by said work support, means supplying coolant to said wheel and work piece, a target remote from the engagement between said wheel and work and connected to said movable support to partake of the movement of said movable support, a screen, an optical system arranged to project a magnified image of at least a portion of said target onto said screen transverse to said plane, said screen having an image thereon of the same scale as said target image, and means for. moving said movable supportin said angularly related directions in a manner to cause said target image to trace said screen image and thereby control the work contour generated by said wheel, said work support having a workcarrying spindle mounted for rotation about an axis lying substantially in said plane and said screen image having an internal contour to be traced by said target.

JAMES A. ALLAN. FRANCIS C. SAVAGE.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,766,800 Peterson et al. June 24, 1930 2,116,593 Bouvier et a1 May 10, 1938 2,145,116 Howard Jan. 24, 1939 2,218,775 Turrettini Oct. 22, 1940 2,331,337 Meyer Oct. 12, 1943 2,388,172 Michailofi Oct. 30, 1945 2,446,575 Cooke Aug. 10, 1948 FOREIGN PATENTS Number Country Date 553,594 Great Britain May 27, 1943

Images