US2804722A - Cutter sharpening machine - Google Patents

Description

L. o. CARLSEN ET'AL 2,804,722

CUTTER SHARPENING MACHINE Sept. 3, 1957 9 Sh'ets-Sheet 2 Filed Aug. 24, 1953 INVENTORS LEONARD QCARLSEN EARL D. DAMMERT FIG. 3

ATTORNEY Sept. 3, 1957 L. o. CARLSEN EI'AL 2,804,722

CUTTER SHARPENING MACHINE Filed Aug. 24, 1953 9 Sheets-Sheet 3 INVENTORS NARD o. RLSEN L D. DA ERT FIG. 8

A TTORNEY P 3, 1957 o. CARLSEN ETAL 2,804,722

CUTTER SHARPENING MACHINE 9 Sheets-Sheet 4 FIG II I74 I76 INVENTORS LEONARD 0.CARLSEN BY EARL D. DAMMERT lawn/w. 9

ATTORNEY Filed Aug. 24, 1953 Sept. 3,1957 o. CARLSEN ETAL 2,804,722

CUTTER SHARPENING MACHINE Filed Aug. 24, 195; I 9 Sheeis-Sheet 5 FIG. I2

INVENTORS LEONARD O.CARLSEN FIG 3 EARL D. DAMMERT Q! MM ATTORNEY p 1957 L. o. CARLSEN ET AL 2,804,722

CUTTER SHARPENING MACHINE 9 Sheets-Sheet '7 Filed Aug. 24, 1953 W G F N E m5 T Y. TL E NR N m m N M 1 10 A T. M A A D M .mA LE V: B

P 1957 1.. o. CARLSEN ETAL 2,804,722

CUTTER SHARPENING MACHINE Filed Aug. 24, 1953 9 Sheets-Sheet 8 v INVENTORS LEONARD o. CARLSEN By EARL D. DAMMERT ATTORNEY Sept. 3, 1957 L. o. CARLSEN ETAL 2,804,722

CUTTER SHARPENING MACHINE Filed Aug. 24, 1953 9 Sheets-Sheet 9 FIG. 22

F I6. 24 INVENTORS 228 LEONARD o. CARI-SEN BY E'ARL D. DAMMERT Arm/my CUTTER SHARPENING MACHDJE Leonard O. Carlsen, Rochester, and Earl D. Dammert,

Penfield, N. Y., assignors to The Gleason Works, Rochester, N. Y., a corporation of New York Application August 24, 1953, Serial No. 375,870

22 Claims. (Cl. 51-33) The present invention relates to a machine for sharpening cutters, such for example as disc and face mill cutters used for cutting bevel gears.

States Patent F Such a machine comprises a frame having a support 3 for a cutter that is to be sharpened, and an oscillating wheel head for carrying a rotating abrasive wheel back and forth across the face of a blade of the cutter, the

axis of rotation of the wheel being inclined at an acute angle to the axis of oscillation of the wheel head. The working face of the wheel is frusto-conical and of such cone agle that its locus of contact with the cutter blade lies in a plane perpendicular to the axis of oscillation. According to one aspect of the invention, the wheel head is mounted for oscillation on a turret that is adjustable on the frame about an axis perpendicular to the axis of oscillation, whereby the sharpening plane, i. e. the plane of contact of the wheel with the cutter blade, may be adjusted to any desired angle about the turret axis.

Preferably the turret adjustment axis lies at least approximately in this sharpening plane; and, to further facilitate the desired adjustment of the locus of the sharpening action, the turret is secured to the frame by means of a vertically adjustable slide.

According to another aspect of the invention, the turret contains a mechanism for oscillating the wheel head and for periodically swinging it about its axis of oscillation to a position clear of the cutter to enable indexing to bring a succeeding blade of the cutter into position for sharpening. Turret-contained mechanism also feeds justable along its axis of oscillation relative to the turret.

The support for the cutter preferably comprises a spindle journaled in a work head that is adjustable universally on the frame to bring any of various typesand sizes of cutters into the desired relation to the abrasive sharpening wheel. A notched index disc on the. spindle is engaged by a spring-pressed pawl which may be lifted to free the spindle for indexing. For lifting the pawl there is a handle which has an angular play connection with the pawl and is urged to its rest position, to allow the pawl to engage the index disc, by spring means which act between the pawl and the handle. By this arrange ment the pawl spring and the handle spring are, in eifect, arranged in tandem so that in order to release the pawl the operator need apply to the handle only the force necessary to overcome the pressure of the pawl spring,

yet the handle may be released by the operator and re- The foregoing and other objects and advantages of the d invention will appear from the following description made with reference to the drawings, wherein:

Fig. 1 is a plan view of the machine adjusted for sharpening a face mill cutter which is shown mounted thereon;

Fig. 2 is a front elevation of the machine;

Fig. 3 is a sectional view taken approximately in the plane indicated by line 33 of Fig. 1, through the wheel head andthe related parts of the machine, the upper part of the view being approximately inthe planes indicated by line 3-3 of Fig. 4;

Fig. 4 isa view of the turret for the wheel head with one of its cover plates removed, the view being in the direction indicated by line 44 in Fig. 3;

Figs. 5, 6 and 7 are sectional views taken in the respective planes indicated by lines 55, 66 and 7-7 of Fig. 3, the plane of Fig. 7 also being indicated by line 7}-7 in Fig. 8;

Fig. 8 is a section taken in the several planes indicated by line 8-8 of Fig. 7;

Fig. 9 is a vertical sectional view through the work head and related parts of the machine, taken in the plane indicated by lines 99 in Figs. 1 and 12;

Fig. 10 is a cross-sectional view through thehandle for lifting the pawl, taken in the plane indicated by line 10--10 of Fig. 9;

Fig. 11 is an axial sectional view taken in the plane shown by line 11--11 of Fig. 10; V

Fig. 12 is a side elevation, partly in vertical section, of the work head and related parts of the machine;

Fig. 13 is a detail sectional view taken along line 13-13 of Fig. 12;

Fig. 14 is a diagram showing the phase relation of the cam-eifected motions of the wheel head;

Fig. 15 is a partial plan view of the machine with a disc cutter mounted thereon;

Fig. 16 is a detail sectional view of the clamp for the sliding base;

Fig. 17 is a detail sectional view illustrating a dashpot stop means for determining the index-dress position of the wheel head;

Fig. 18 is a wiring diagram of the machine;

Fig. 19 is a fragmentary front elevational view. showing on a larger scale the relationship between the abrasive Fig. 24 is a detail sectional view taken approximately in the plane indicated by section line 2424, of Fig. 22. Referring to the general organization of the machine asshown in Figs. 1 and 2, there is a frame 21 having a column 22 with vertical ways 23 along which a slide 24 is adjustable. A turret 25 is adjustable on the slide about a horizontal axis 26 and carries a wheel head 27 for oscillation about an axis 28 that is perpendicular to axis 26. An abrasive wheel W having a conical working sur face is mounted on a spindle that is rotatable in the wheel headon an axis that is inclined at an acute angle to the axis of oscillation 28. The wheel is oscillated back and forth across the front face'of a blade of a cutter C to be sharpened, the conical surface of the wheel contacting the blade along a plane perpendicular to axis 28. As.

shown in Fig. 3 (and also in Figs. 19 and 21)'the turret adjustment axis 26 lies substantially in this plane, which, r

Patented Sept. 3, 1957 .9 is known as the sharpening plane. The head periodically swings far enough, in a clockwise direction in Fig; 1,- to

carry the wheel W clear of the cutter to permit indexing of the latter to bring successive blades into position to be sharpened, and to permit dressingofthe' wheel'by' means of a diamond D carried bya dressing arm29*thatis supported on turret 25.

The cutter'C to'be sharpenedis mountedion' a'spindle that is journaledin' a work head'31. This head. is adjustable upon a turret 32 about a horizontal axis 33'which intersectsthe spindle axis atright'angles, and the turret is adjustable 'on across-slide 34'about a vertical axis 35 that'intersects axis"33. The cross-slideiis adjustable in the direction ofarrow 36 on a sliding base 37which -iri turn is'movable'in thedirection of arrow 38 along ways 39 onthe frame 21. By, the aforementioned adjustments I that are provided'for wheel head 27"andliwork head 31,

cither'aface mill cutter C, such assh'own in Figs. 1 and.2,.

or a. disc cutter C Fig, 15; maybe brought into position and rake angle by the rotating and oscillating wheeLW.

During sharpening a suitable liquid: coolant may; be

forced bya pump 40, driven by a motor-41, from a sump in the frame 21 through-a conduit.42, chamber. 4-3,."conduit'44 and'nozzle 45 onto the cutter blade that is'being acted on by the wheel;

Referring now to the wheel headand. the means for supporting and operating it, the slide 24--i s adjusted ver-" tically alongways'23 of column-22 byzmeans of a screw 46, Fig. 3, that is screw-threadedto a nut carriedbylhe slide and. is journaled for-rotation in the column: The

adjusting screw is turned by means of'acalibrated -ad-- justingknob 47, and after such adjustment the slide is clamped to the column by tightening a gib 48 by; means of aclampserew (not showrr). The-position of adju'stment of the slide is shown by a-scale 49. Theturret-25 includes a journal 51-that is'rotatably adjustable-'in slide 24 about axis 26 by turning a worm 52, thisworm *beingi.

journaled for rotation in the slide and meshingwith a worm wheel 53 secured to journal 51. After such angular adjustment of the turret, which determines the direction of the plane in which thewheel W oscillates, the turret may be clamped by means of a screw 54.- Access to 'anadjusting knob on worm 52 a11d a handle onclamp screw 54, and also to other parts within column, 22,- is' obtained by. opening doors 55. The angular-position-ofturret-25 is shown by a cooperatingscale and pointer: 50' on the turret andslide24, Figsland-l5.

The'wheellW is:mounted on thearrnatureshaftof: a-:'

motor. 56 that ismounted within the wheelhead 27, and

to dissipate heat from the motor the surroundinggsurface:

of the head is provided-with cooling fins. For supporting the head for oscillation about axis 28, it isprovided with opposed trunnions 57 journaled in bearings 58 in'turret 25. As the head is oscillated it isalso fed along .axis

28, sothat on each pass across the-work the wheel will remove slightly more stock. The bearings 58-accommodate this axial feed motion which is impartedto-th'e head'through anti-friction axialthrust bearings 59. The

to'hav'e its blades sharpened toany desifedhookangle Aligned with andidriven by the motor shaft is a worm 64' meshing with 'a worm wheel 65, Fig. 6, securedtoashaft- Y which carries an elongated pinion'66. Figs. 3, v7 and.:8.- This pinion drives a gear 67 on a cam 68 that 'is rotatable,

but axially immovable, upon ashaft 69' parallel to" axis" 28. The cam has a continuous peripheralfeed track 'll' engaging-1a follower roller 72-0n the feed slide'eli. The? shape of this 'feedtrack is such that on each complete: turn of the cam theslideis. slowly moved (upwardly 'in Figs. 2, 3 and 8) to feed the wheel W into the cutter C starting position.

The cam 68 also has in one end face a cam track 73 that is open at 74, at a point diametrically opposite to a circular arc portion thereof. Track 73 engages a follower roller 75 that is eccentrically mounted on a stub shaft 76 journaled on anti-friction bearings 77 in a gear segment 78; This segment'is'mounted for oscillation in the turret 25 about an axis 79, Fig.7, and meshes with a pinion segment 81 secured-to a trunnion 57 of t-he wheel head. A pinion 82 secured to stub shaft'76 is driven, through an idler gear 83 that is'r-otatable on axis 79,- by a gear 84"that is on the same shaft with worm wheel 65 and elongated pinion 66. Whenthe cam 68 is turned to such position that the circular arc portion of track 73 engages the eccentric follower 75, then, as the stub shaft 76 is rotated through the gear drivejust described, the eccentricity of the follower willcause the shaft.76and gear' segment 78 to oscillate about axis 79, makingqone oscillation for each turn of'stub' shaft 76.- This motion is transmitted through pinion segment 81to the wheel head27, thereby oscillating the wheel W back and forth across the front face of the cutter'blade. As previously described, during such oscillation the wheelis gradually fed-into the Work along axis 28 so that on each stroke additional stock is ground from the cutter blade.

While the circular arc portion of cam track 73 engages eccentric 75'a circular arcportion 85 of pinion:

segment 81 is engaged by a roller 86 carried by a springbacked plunger 87'sli'dable in the turret 25. Howeverwhen the cam 68 turns far enough that the non-circular part of'track 73 engages the eccentric, thernean position of the oscillating gear and pinion segments is shifted angu larly. Fihally, when the track 73 is .inthe position shown injFi'g- 7, .the segments areshifted far enoughthat thethe motionof theweel. head into the dress-index position determined by stop; 89. For this purpose the stop is in the form of a spring-backedplunger, best seen in Fig. 17.

The plunger has a limited motion, vertically in Fig, 17, in-

a bore in the turret and seats upon a plug that .is screwthreadd'into the turret. The oil can freely enter the chamber betweenthe plunger and the plug by opening of a checkvalve'90 -when the plunger is moved in the direction"urged"b y its spring, butcan escapew only slowly through a metering orifice around'th'e valve when the valve 'closesupon'the plunger being moved in the'oppositedirectionbythe pinionsegment 81'as the wheel head is swung into its dress-index position-by spring pressediroller 86'.

To provide wheelstock' for dressing, the cam 68is fed axially, carrying with it the feed'slide 61, wheel head 27 and wheel W: This axial motion is'effectediby rorating the shaft '69-on which the cam is rotatable. This shaft is movable axially, but not angularly, in theturret 25,- and it is scrcw-threaded'to a'worm wheel 91, Figs. 6 and 8, that is'held against axial motion in the turret. A worm=92 meshing with theworm wheel 'is mounted on a shaft"93which=at one end has a spur gear 94 and at the other a calibrated adjusting knob 95. A similar knob 96carries'a spur pinion meshing withgear 94. Thus, the operator can turn in the same direction either knob. 95 or'96; which ever ismost convenient, in order toteed the wheel to provide stock for dressing? It will be under stood in this connection that in some-positions ofadiustment of the turret the operator may face knob 95 while in other turret positions he may face knob 96, and confusion is avoided if he can always turn them in the same direction.

Secured to one trunnion 57 (the upper one in Fig. 3) are cams 97 and 98 which are adapted to actuate limit switches 99 and 100 mounted on the turret 25. Switch '99 is normally closed and controls a clutch-brake unit 102 that is interposed between the armature shaft of motor 63 and worm 64, while switch 100 is normally open and controls lamp 101 which lights to signal that the wheel head has reached its indexing and dressing position. Cables 103 and 104, respectively for supplying current to motor 56 and for the leads to the limit switches 99and 100, are joined with cables 105 and 106 respectively from the motor 63 and clutch brake unit 102, the joined cables having suflicient length between the turret and the frame to enable the turret to be adjusted through a full turn about axis 26. The cable 103 is wound into a helix within trunnion 57 that is of 'suflicient length to flex easily to accommodate the oscillation of the wheel head. To prevent adjustment of the turret through substantially more than one turn, cooperating stop parts 107 and 108 are provided respectively on the journal 51 and slide 24. Stop 108 is pivoted at 109 for limited motion between fixed abutments 111, its pivotal motion enabling the stop 107 to turn through very slightly more than 360 about axis 26.

The tracks 71 and 73 of cam 68 are preferably so shaped that the feed and wheel-throw motions respectively produced by them will be in the phase relationship shown in the diagram, Fig. 14.

The electrical system for the machine, shown in Fig. 18, includes, in addition to the elements previously referred to, a three-wire alternating current supply with main leads L1, L2 and L3, a controller 112 for connecting coolant motor 41 and wheel motor 56 to the leads, a controller 113 for connecting drive motor 63 to the leads, a reversing switch 114 for motor 56, a rectifier 115 to provide direct current to clutch winding 116 and brake winding 117 of the clutch-brake device 102, a controller 118 for device 102, and several push-button switches. The latter comprise start and stop switches 119 and 121 for the coolant and wheel motors 41 and 56, start and stop switches 122 and 123 for the drive motor 63, and a feed start (clutch) switch 124.

The machine is stopped with the cam 68 in the degree position shown at the left of Fig. 14, wherein both tracks 71 and 73 are at dwell. To start the machine the Wheel motor start switch 119 is momentarily closed, thereby establishing a circuit from lead L1 through stop switch 121, the start switch, lead 125, and the winding of controller 112 to lead L2. This energizes the controller 112 and causes the wheel motor 56 to run in whichever direction is selected by reversing switch 114, the direction selected depending upon the relative position of the cutting edges of the cutter blade to the wheel. As soon as controller 112 is energized a shunt circuit is established around the start switch 119, from stop switch 121 through lead 126 and a now closed contact of the controller to the controller winding, so that opening of switch 119 now has no effect, and the wheel motor will continue to operate until stop switch 121 is opened.

Next the drive motor start switch 122 is closed, starting the motor 63 by energizing the controller 113 through a circuit from lead L1 through stop switch 121, lead 126, contact of controller 112, lead 125, stop switch 123, start switch 122, lead 127 and the winding of controller 113 to lead L2. As soon as controller 113 is energized a shunt is established around switch 122 so that opening of it has no efiect, this shunt being from stop switch 123 through a lead 128 and a now closed contact of controller 113 to the controller winding. Hence motor 63 will continue to run until either stop switch 123 or stop switch 121 is opened.

Now the clutch coil 116may be energized, to cause andthe winding of controller 118 to L2. Accordingly controller 118 is energized so that its contacts 131 and 132 close and its contacts 13 and 14 open. The clutch coil 116 now is energized by a circuit from the positive terminal of rectifier 115, contact 132, and coil 116 to the negative terminal 'ofzthe rectifier.

The cam 68 is now rotated by the drive from motor 63. The .cam tracks 71' and 73 remain at dwell until position 135, Fig. 14, is reached. At this time track 71 begins to return the feed slide 61 from its most advanced position (i. e. from its uppermost position in the sense of Fig. 3) and the'cam track 73 begins to regain control of eccentric 75. At position 136 the return motion of the feed slide is concluded. and its advance or infeed by track 71 is begun.. Track 73 has now engaged the rotating eccentric 75 so that thewheel head is being oscillated about axis 28, and the track has started to shift the eccentric clockwise in Fig.7 about axis 79, so that the oscillating wheel Wis being swung into engagement with the cutter C.

As soon asthe wheel head is swung far enough to move the lobe of cam 97 away from the plunger of limit switch 99 the latter closes, thereby establishing a shunt circuit around feed start, switch 124. .This shunt is from lead 127 through switch 99, and contact 131 to the winding of relay 118. .After the shunt is established the opening of switch 124 will have no etfect'and the clutch winding 116 will remain energized until limit switch 99 or stop switch 121 or 123 is subsequently opened.

When the rotating cam 68 reaches position 138, Fig. 14, the feed motion of slide 61 effected by track 71 has proceeded far enough to take up any play in the feed mechanism, and the rotating eccentric 75 is engaged with the circular arc portion of track 73 so that the wheel W is oscillated across the face of a cutter blade. The wheel infeed effected by track 71 continues at a constant rate until at position 139 it slows and at position 140 it stops,

so that the last few strokes of the wheel across the cutter blades are made without infeed. Then at position 141 the track 73 again begins to swing eccentric 75 counterclockwise (in Fig. 7) about axis 79 to move the path of the oscillating wheel W away from the cutter blade. At

position 142 the track 73 has reached the dwell during contact 132. Simultaneously the brake winding 117 isenergized through a circuit from the positive terminal of rectifier 115, contact 134, and winding 117 to the negative terminal of the rectifier. Accordingly the device 102 brakes the drive worm 64 and disengages it from the drive motor 63. By'the time the worm is stopped the cam 68 has reached its 360 or 0 degree position, and one cycle of the machine has been completed.

At this time the cam 98 closes normally open limit switch to establish a circuit which lighs indicator lamp 101, the circuit being from lead L1 through contact 133, the limit switch and lamp to lead L2. The cutter C or C may now be indexed to bring another of its blades into position to be sharpened, or the dresser diamond D may be actuated to redress the wheel W, or both the indexing and dressing operations may be performed. Then the sharpening cycle may be restarted by again closing the feed start switch 124.. As soon as the wheel head moves away from dressing position the limit switch 101 of course opens, cutting 011 the lamp.

Reference will now be made to the details of the mecbr anisrnshown in Figs. 9 and 13. inclusivegafor; supporting 31; Rotatableon thespindleis; a master indexfidisc: 145

having, a verylarge number of notches-146a accuratelyspacedabout its periphery andeach. adapteditowreceive. an :index' pawl 147. Detachably secured.:to rdisc: 146;:by: screws 148 is .a masking disc1149 havingrazsmallerinumberv of notches corresponding to. thenumbenofibladeson the particular cutterthat-is to .be sharpenedi. The pawl icana enter only thosenotches-ofithe masterdisc that are aligned. with notches of the masking disc, andforzsharpeninga.

cutterrwith a different numberof. blades.a-.amasking:disc withacorresponding. number ofinotches. is substituted.

A clutch member 151,-.having faee.clutch.teethi152ll meshing:.with' mating .teeth a on. the inner face. of: a :hand

wheel '153, is: also. rotatablezorr thei spindle: and is secured touth'esrnaster indexndisc 145."forrotatiorr therewith :by a -pin'154 The handiwheel issecur'ed to;the spindlef by a.

The-index pawl 147 is secured to-ashaft ISQthat-is journaledon bearings 161 for-rocking motion in a sleeve 162-that is carried-by a worm1wheel-segrnent163; This segmentzis mountedifor rotationabout-the spindle-axison. anrannulus164 secured-to-head-.31. A worm 165- rneshing with the. segment is 'journaled-in the headfor rotation by means of a knob 166, and acoil spring' 167 actsibetween the-head 31 and the'segment-to'constantly urge the: latterin' one direction; clockwise in Fig. 12, to take up backlash between theteeth of the worm and wheels. After adjustment of the segment by turning knot 166, to bring the cutter into the exact position desired about 'the cutter spindle axis, the segment may b'e-clarnped tothe head by-a-disc 168, Fig. 13, and a clamp screw 169 therefor; The screw extends through-an arcuateslot 171 inithehead andis screw-threaded to the segment.

The index pawl 147 is urged into a notch of-the index plate by a spring-backedplunger 172. carried by segment 163. Tolift the pawl from the notch ahandle 173 is retatably niounted on shaft 159. A pin 174" carried by a flange-1750f the shaft extends through an enlarged 'openingl'id in the hub of the handle and-is engaged by a springbacked plunger 177- carried by the hub. The effect of the spring-backed plunger is to urge thehandle, clockwise in Fig. 10, to a limit'p'osition determined by theengagementof a pin 178 carried by the handle with an end wall of a recess 179-in sleeve 162. As shown in Fig. llthere is an opening 181' in the flange 175 to freely passpin 173.

To index the cutterthe operator with one hand first turns-handle'173, counterclockwise in Fig. and clockwise in Fig. 12, to the limit position determined by pin 178andabutment 179; As the handle is turned the wall ofi opening 17dengages pin -174 causing the shaft159 to turn to disengage pawl 147 from the notch-inindex plate 145. Then with his other hand on hand wh'eel 153 the opera-tor'turns the now free spindle143'. As soon as turningof the hand wheel is started-the. handle173 is released wh'ereupon-the spring-backed plunger 172" urges thepawl against the peripheral surface of'the masking disc, along which it-rides until -it drops into the next unmasked notch in the index plate. Assoon' as the handle 17-3 is released the relatively light pressure of springback'ed plunger 177' returns it to its'lirnit'position determined by engagement of pin-178 with the wall of recess' 179. In this way the handle" is normally returned to its rest position before the pawl' again seats in'anotch ofgthe-index plater. To lift thezpawl. the operator need exert only sufiicienttpressure on -thethandlez'to overcome:

the: pressure: of; the: spring vback. oft thev pawlvseatingzi plunger1-172; becanserthe latter is, in effect',-.arranged1in tandem with the lighter spring which backsplunger .177 soJthat theforces exerted by the two. springs-wareznotadded together.

Innorder to check the trueness of the severalcutting.

edges of a cutter-after sharpening, and for other purposes,-. it is at times .desirable tolatch the index pawl in its with drawn position; For this purpose ,a spring-backed plunger. 182- is provided in the hub of handle 173. Whenthe handle is turned to itslimitposition, counterclockwise. insFig; l0, thewplunger may enter arecess 183 in sleeve. 162;.and willremain :th'erein under the pressurelof. its.- spring until: itis-manually withdrawn by pulling, onrits knob'134. A projection 185 onxth'e knob normally enegages the end face ofhandle 17sec holdthe plungerzoutz of recess 183, but when knob 184 is turned so: thatthe" projection is aligned with and can-enter" a recesszl86=tinf the handle, the plungerwill then enter recess 183 the next timethe. index pawl is lifted by turning handle-.173. As shown inlFig. 9-the plunger 182. passes through anenlarged. opening. in shaft flange 175." and hencedoes not engage the latter.

For the purpose of adjustment about axis 33Ithe work head. 31 has 't'runnions 187 journaled for rotation in turret 32, and to seno -trunnion there. is secured aworm wheel 188 meshing with an adjusting worm 189. This worm is:- rotatable in-.the turret by means of a knob 191, Fig. 1,' upon :loosening a clamp: lever 192. As shown in Fig. .12 this-lever is-screw-threaded to the end'of onetrunnion- 137 and acts through a cup-shaped member 193 toclamp against the turret a disc 194that is connected. withthe trunnion by a: key. 195; Cooperating calibrations on thedisc andon theturret showthepositionof adjustment of the work: head; about axis 33;

Theturret'32may be adjusted, aboutvertical axis35', around a center 196 on cross-slide. 34 upon loosening a nut 197 ofza clamp bolt, the head of this bolt being. anchored in a -T-slot (not shown) that extends along sliding base 37in the direction of arrow 36. The turret has an indicator 198'c0operating with a scale onthe crossslide to show'the position of adjustment about axis 35. For quickly bringing the turret to either of the two positions inwhich it is most frequently used (the respective positions shown in Figs. 1 and 15) a spring-backed plunger 199 carried .byt the turret and two cooperating recesses. 20Lin the cross-slideare provided. Theplunger maybe-lifted out of one recess, to theposition shown in Fig. 12, by turning a lever 202 whose shaft has an eccentric 203'engaging the plunger. After the turret is turned enough frornzone position to carry the plunger out ofalignment'with one recess the. lever 202 may bereleased so that the plunger will-drop into the other recess assoon as the turret reachesthe other position.

When the clarnpznut'lQ'i is loosened the cross-slide may also be. adjusted,.this adjustmentbeing along ways 204 on thesliding base 3'7 andin the direction of-arrow 36, Fig. l'. The adjustment is effected by turning a knob 205 that is secured to a screw 206, the latter being journaled torotate in the: sliding base and screwthreaded to. 2. lug Z07 on the cross-slide. A scale208- on the sliding base and a cooperating indicator on the cross-slide show the position of this adjustment.

The sliding base is adjustedalong ways 39 in the direction of arrow 38, Fig. l, by turning a handwheel 211 securedto a screw 212. This screw is mounted for rotation in the frame 21 and. is screw-threaded to 2. lug 213 on'the' sliding base. A scale on the frame cooperatingwith a pointer 214 on the sliding base shows is slidable in a sleeve 217 carried by the frame. The-bolt-v sliding base, this slot extending in the direction of arrow 38, Fig. 1. A nut 218 is secured to the lower end of the bolt and when the lever is raised this nut is forced away from the sleeve 217, to thereby draw the sliding base against the frame. Friction holds the lever raised until it is manually released. Pins 219 retain the lever on the bolt 216 when it is released.

It will be understood that by the adjustments described a cutter C or C on the machine may be brought to any desired position relative to the wheel W in the direction of arrows 36 and 3S and about axes 33 and 35. Adjustment in the remaining direction, vertically, is accomplished by moving the slide 24 along ways 23 as before described. For providing room between the work head and the wheel head to remove or replace a cutter on the spindle 143, the sliding base is readily withdrawn by releasing lever 215 and turning handwheel 211, without affecting the other adjustments.

Between successive resharpenings a cutter is ordinarily turned on its axes through a small angle to advance the blades by an amount equal to the thickness of stock to be removed. Thus, a cutter C may first have all of its blades rough sharpened, then be rotated through a small angle by turning knob 166 so as to advance the front faces of the cutter blades by one or a few thousandths of an inch, and then have all of its blades finish sharpened. With the present machine another method of advancing the cutter blades between succssive sharpenings' may also be followed, this method comprising advancing the wheel W rectilinearly into the work by turn ing knob 47. By'the first method the front face of each blade is successively sharpened back in radially related planes, whereas by the second method it is sharpened back in parallel planes.

In the event it is desired to sharpen cutters of only one kind of machine may be simplified by eliminating certain of the aforementioned adjustments. For example, if it is desired to sharpen only disc cutters of the kind shown at C in Fig. 15, then the work head 31 may be rigidly mounted upon the sliding base 37 in the position shown in that figure, thereby eliminating the adjustments about axes 33 and 35, Figs. 1 and 2, and in the direction of arrow 36.

Referring to Fig. 19, the angle between the axis of rotation of the wheel W and the axis 28 is designated A, and the peripheral edge of the wheel, other than the edge of the working face of the wheel, is designated E. In both Figs. 19 and 20 the edge E is shown in full lines when the wheel is at the center of its swing, i. e. when its axis lies in the common plane of turret axis 26 and axis of oscillation 28. As the wheel swings about axis 23 toward its dress-index position the plane of edge E also is displaced about axis 26 with the result that the edge will interfere with a blade of the cutter adjacent to the blade being sharpened, if the blades are very closely spaced. In Fig. 20 the edge E is shown at E in its position of swing about axis 28 in which maximum interference develops. The interference of the edge E in this position with the cutter blade that is immediately be-- neath the one being sharpened appears in Fig. 19.

In order to avoid such interference, in cases where the machine may be called upon to sharpen cutters with closely spaced blades, the diameter of the wheel W may be decreased, or, preferably, the angle A decreased. The effect of such angle decrease is shown in Fig. 21 where the angle A is half of the angle A in Fig. 19. With this change the wheel even when swung to the position of maximum interference, wherein the edge E assumes the position shown at B, does not interfere with the adjacent cutter blade. In order to maintain the thickness and strength of the wheel and also to provide adequate wheel life, the wheel is preferably made to dish shape, so that in axial section is appears as shown at the right of Fig. 21.

The particular dresser illustrated as comprising arm 29 is the subject of our division patent application Serial No; 475,784, filed December 16, 1954, for Wheel Dressing Device. Referring to Figs. 15, 22, 23 and 24, the dresser arm 29 is mounted on a rock shaft 221 that is journaled on anti-friction bearings 222 in a dresser housing 223. This housing is mounted on the turret 25 for. adjustment, along a way 223', Fig. 1, that is parallel to axis 26, to such position that when the wheel W is in its index-dress position shown in broken lines in Fig. 15, "i. e. in the limit position determined by stop 89, Fig. 7, the arcuate path 224 of the diamond D about the axis of shaft 221 is substantially radial of the wheel at a means point on the wheels active surface. With this arrangement the active surface of the wheel may be dressed to an almost exactly conical shape.

The dressing stroke of the arm 29, clockwise in Figs. 15 and 23, is effected by a coiled compression spring 225 moving a plunger 226 that is slidable in the housing, the

plunger having rack teeth meshing with teeth 227 on the shaft. The assembly comprising the spring and plunger and arm is cocked for its dressing stroke by turning the shaft counterclockwise by means of a handle 228 which is pivoted to the shaft by a transverse .pin 229; and the assembly is held cocked by abutment of a pin 231 on the handle with a pin 232 carried by the housing. The

handle carries a spring-backed plunger 233 which constantly urges it about the axis of pin 229, in a counterclockwise direction in Fig. 22, to maintain the pins 231, 232 in abutting relation. after the assembly has been cocked, the operator need only push the handle 228 about the axis of pin 229, to the broken line position of the handle shown in Fig. 22. This releases the pin 231' from abutment with pin 232 and allows the spring 225 to move the assembly through its dressing stroke.

The velocity of this stroke, which determines the texture of the surface dressed on the rotating wheel W, is controlled by hydraulic dash-pot means. For this purpose the interior of the housing, including the cylinder chamber 234, and also the oposite cylinder chamber which opens into bore 230 in the end of the plunger 226, is filled with hydraulic fluid. The passage in the plunger connecting bore 230 with chamber 234 is closed by'a spring-pressed ball check valve 235 arranged to open to freely pass fluid from the bore to the chamber and to close to prevent fluid flow in the opposite direction. However fluiddisplaced from chamber 234 by the springurged motion of plunger 226 passes to the opposite cylinder chamber through communicating passages 236, 237 and 238 in the housing.

From passage 238 the fluid flows through a passage in a screw 239 into an annular groove 241 of a rotary valve 242 which is supported by the screw. From this groove the fluid passes through a passage 243 in the valve into either port 244 or port 245 in the adjacent wall of the housing. These ports respectively open through passages 246 and 247 into the cylinder chamber that includes bore 230. Passage 246 is partially obstructed by a springlocked adjustable plug valve 248 that is adjusted to permit a fairly fast flow of fluid, while passage 247 is obstructed partially by a similar valve 249 adjusted to permit a slower flow of fluid.

The rotary valve 242 has a handle 251 by which it may be turned on screw 239 between opposite limit positions that are determined by abutment of a pin 252 on the housing with the ends of an arcuate recess 253 on the inner face of the valve. When handle 251 is turned counterclockwise to its limit position "shown in Fig. 22 valve passage 243 is aligned with port 244 and hence the dressing stroke of the diamond will be fairly fast, as is normally wanted to produce a coarse finish on the wheel for a rough grinding or sharpening operation. If the handle is turned to its opposite limit position, as at 251 in Fig. 22, passage 243 is aligned with port 245 and To effect the dressing stroke I badly chipped, it may be desirableto rough sharpen all 1 of the blades around the:cutter oneor more times to remove the damaged stock, and then to finish :sharpen' all of the blades. After all the cutter blades have been rough sharpened, the 'cutter'maybe rotated .slightly to provide stock for a subsequent sharpening, by turning'sadjustingf15 knob 166 after first'releasing'clamp 169;

Having now described'the machine which constitutes the preferred embodiment ofthe invention; and-'th'e method of operation and theuse of the machine; what we claim as our invention is:

'1. A cutter sharpeningfmachine comprisingsaframe having a cutter support, a turret angularly' adjustableon the: frame, a wheel head mounted for oscillation on the turret about an axis perpendicular totheturret adjustment axis, means on the wheel 'headforsupporting anabrasive Wheel for rotation about an axis inclined at an acute angle to theaxis of oscillation, an abrasive wheelsosupported having the active surface thereof inclined to'the plane of wheel rotation 'at the same acute angle-whereby" during the oscillation said active surface traverses a cutter" 39 on the cutter support in a planeiperpendicularto'the axis I of; oscillation, and means for. eliecting such oscillation ofthe wheel head.

2. A' machine according to claim 1 in'which the turret adjustment axis lies at least approximately-in said plane perpendicular to the axis of oscillation.

3. A'machine according to claim 1 in which'the cutter support comprises a workheadiand a work spindlecarried thereby, the work headand said turret beingrelatively adjustable in' the direction'of the turret'adjustment axisp 4. Arnachine according to claim 3in which thework head and said turret are also adjustable relative to'each other in a direction perpendicular to the turret adjustment axis. i

5. A machine according to claim 3 in whichth'e wor k head is-adjustable recti-linearly on the frame in'th'e direction of -.the turret adj'ustment'axis and said turret is ad justable rectilinearly on the frame -in-a=direction-- per-' pendi'cularto said adjustment axis.

6. A machine according to'claim -5 in which th'e work 5 head is also adjustable in a direction perpendicularto both-ofthe aforementionedrectilinear adjustments; and V is further adjustable about two axes that are perpendicular toseach other and to the cutter spindle axis.

7. A machine accordingto claim 1 in which there is a mechanismwithin ithe turretfor oscillating-the w-heel head to passthe wheel over a cutter. support, said-mechanism' including means for periodicallyswinging -the wheel head through a greater angle about the axis of oscillation to a position clear of the cutter to permit indexing'the cutter about its axis.

8. A machine according toclaim 7 inwhichthere is a means for feeding the wheel head upon the turret along r theaxis of oscillation as said head is oscillated-to pass the'wheel over the cutter and for thereafter returning .the

wheel head to its initial position along the axis of oscilla tion.

9. A machine according to claim7 in whichlthere-i isw a means mounted on the turretfo'r dressing thetabrasive.

wheel when the wheel is in said-position for-indexing: 7 0"- ll... A"cuttersharpeningtmachineacomprising a frame,

a world-head on the frame, a work spindle-"rotatable'in the work 'head, awheel head movableon the frame to passan abrasive wheel carried thereby across acutter'on said: spindle, a'multiple-notchedindex disc on the spindle, a. pawl pivoted to the-work head, springmeans acting between theJwork'head and the pawl forurging pivotal motion of thelatter into seated relation in a notch insaid disc, a handle for lifting the pawl from such notch to freethe work' spindle for-rotation, the-handle having limited angular motion relative to the pawl, a stop to limit angu lar motion of the handlerelative to the work' head in a direction to lift the pawl, and spring means acting between the: pawl and the handle for urging the handle against said-:stop;

l2. A':mechanism comprising asupport, a notched member movable relative to the support, a pawl pivoted to the support, spring means for urging pivotal motionof the'pawl into seated relation ina notch in said member, a handle for the pawl connected thereto for limited 'rela tive angular motion, a stop to limit angular motion of the handle relative to the support in a direction to unseat the pawl, and spring means acting between the pawl and v the handle for urging the handle against said step.

l3; A cutter sharpening. machine comprising a sup port, a wheel head mounted on the support for oscillation and also for motion along .the axis ofoscillation, rneans on the wheel head. supporting .an-zabrasive wheel for rotation about an axis inclined to the axis of oscillation,means.including a rotatable eccentric for oscillating the wheel head, and means including a cam rotatable in the. support and geared to the eccentric for rotation in timedsrelationship therewith for feeding the wheel head along the axis of oscillation and then returning it to itsinitial position therealong.

14. A machine according to claim" 13 in which the eccentric is-rotatable on a member movable within the support for oscillating the wheel head, and the cam is arranged to move the'eccentric to thereby swing the wheel headabout its axis of oscillation into and away'from' cutter sharpening position;

15. Acutter sharpening machine comprising a support, a wheel head mounted on the support for "angular oscillation, a member movable in the support for effecting such oscillation, an eccentric rotatable on said member; a cam rotatable on the support and geared to the eccentrio for rotation in time therewith, said.cam;being:.ar-"- ranged to control the position' of the eccentric and having a dwell 'portion'and an active portion, whereby during" the portion of each revolution when'said dwell .portionr is efiective the-wheel head is oscillated through a'prede-s termined angle relative to thesupport and. during; the portion of each revolution when said active portion is.

eifective thewheel head is swung beyond the-limits of said predetermined angle.

.16. A cutter sharpening machine according to claim l5 in which there is a discontinuity in said active portion of.the cam, which, when effective, frees the eccentric for idle rotation, andmeans acting between the wheel head and the support for swinging the wheel head to a fixed limit position when the eccentric is so freed.-

17. A cutter sharpening machine according to claim .16 in which the means'acting between the wheel head and the support comprises a cam having a dwell surface and an-active surface, said cam being movable with the wheel head, and a spring-pressed follower for said cam carriedby the support;

18. A machine com rising a support,'a cam rotatable in the support and having track with a dwell portion andanactive portion with a discontinuity between parts of said active portion, a member movablein the support and an :eccentric rotatable on the member andengaged in thetrack of the cam, and means for rotating'the eccentric and thecam: whereby whenithe dwell portion: of the track positions. the'eccentric. themember is oscillated bythe' eccentric, when the active portion of the track positions the eccentric the path of oscillation of the member is shifted, and when the discontinuity of the track is effective the eccentric is freed for idle rotation.

19. A machine according to claim 18 in which there is a spring means to position the member relative to the support when the eccentric is freed for idle rotation.

20. A cutter sharpening machine comprising a frame having a cutter support, a turret angularly adjustable on the frame, a wheel head mounted for oscillation on the turret about an axis perpendicular to the turret adjustment axis, means on the wheel head for supporting an abrasive wheel for rotation about an axis inclined to the axis of oscillation, means for oscillating the wheel head, and means for concomitantly feeding the wheel head along the axis of oscillation and for periodically returning it to its initial position therealong.

21. A cutter sharpening machine comprising a frame having a cutter support, a turret angularly adjustable on the frame, a wheel head mounted for oscillation on the turret about an axis perpendicular to the turret adjustment axis, means on the wheel head for supporting an abrasive wheel for rotation about an axis inclined to the axis of oscillation, and cooperating stops on the frame and on the turret to limit the turret angular adjustment, one of said stops being movable on the part which carries it to enable the adjustment to be made through at least 360 degrees.

22. A machine tool having two parts arranged for relative angular motion, a stop carried by each part, said stops being arranged for abutment with each other to limit such angular motion in one direction and also for abutment with each other to limit such angular motion in the opposite direction, and one of said stops being mounted for limited back and forth motion, on the part which carries it, in response to abutment of the stops, the direction of said limited motion being such as to extend the range of said relative angular motion, and the magnitude of said limited motion being such that the angular motion may be through at least 360 degrees.

References Cited in the file of this patent UNITED STATES PATENTS 856,662 Smith June 11, 1907 1,811,254 Bayley June 23, 1931 1,830,971 Taylor Nov. 10, 1931 2,077,727 Ward Apr. 20, 1937 2,224,959 Galloway Dec. 17, 1940 2,231,762 Johanson Feb. 11, 1941 2,352,489 Melin June 27, 1944 2,375,703 Swartzwelder May 8, 1945 2,439,263 Overstedt Apr. 6, 1948 2,441,784 Worthen May 18, 1948 2,441,832 Morawski May 18, 1948 2,451,235 Nagy et al Oct. 12, 1948

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