[1]2,429,250 5 boss 44, which (as seen in Flgure 9) provides the required metal for forming T-slot 32. )3y reason of the interconnected webs and ribs, and the fact that the lower surfaces of ribs 33, 34, 36 and 37 are utilized as bearing surfaces engaging the top of the work table, an extremely strong and rugged table unit is provided, and one which transmits the cutting or grinding forces to the main table in such manner as to avoid any strains that would result in distorting or "springing" the parts sufdciently to Impair the accuracy of the apparatus. In order to facilitate finishing of top surface 31 of the auxiliary tabie in a simple surface grindIng operation. a pair of lugs 45 are cast on Its lower side and have their lower surfaces disposed in the same plane as the bearing faces of the ribs. -'Accordingly, the auxiliary table may be so supported on the grinding machine during manufacture throughout Its length by the ribs and lugs that It will not undergo distortion during the grinding operation. After manufacture of the table has been completed, lugs 45 may be removed If desired. The novel manner in which the auxihary table is held in place by the pilot member will now be described. Referring to Mgures 7, 8 and 10, the pilot A is of.generally disc-lik e form and fs@ provided with a central opening 47 (Figure 10) and a cylindrical periphery 48, carrying graduations 49 (preferably being divided up directly Into degrees running from zero to 45' in each direction from the zero or parallel position of the tables shown in Flgu-re 8. The pilot member is secured to the main work table 23 by means of a pair of T-bolts 31 having heads seating in T-slot 25 Of the table and projecting upwardly Ichrough diametricai]y spaced openings in the pilot member. A pair of nuts 52, seating in a pair of recesses 53 in the pilot member, are turned on the T-bolts and frictionally clamp the pilot member to the main table. The pilot member is accurately positioned witli respect to the main table by means of a pair of keys 55 secured in a longitudinal keyway 56 In the underside of the pilot member bk means of cap screws 57 and projecting partially Into T-slot 25 adjacent each T-bolt 51, as seen in Figures 8 and 10. Accordingly, by loosening nuts 52, pilot member A may be freely slid along the top of table 23, being guided by keys 55, and locked rigidly in any desired adjusted position by tightening -nuts 52. The auxiliary table Is secured in place on the pilot member and work table in a manner seen more clearly in Mgures 7 and 10 ' The auxiliary table and the pilot member are provided with aligned mating openings 59 and 61, respectively, and after manufacture and grinding of the auxiliary table is completed a trunnion or pivot plug 62 is frictionally fitted into opening 59 of the table, so as to pivotally project into opening 61 of the pilot member. If desired, the plug may alternatively be frictionally fitted into opening 61 of the pilot member and disposed in journalling relationship with opening 59 of the table. From the foregoing structure it is apparent that the pilot member may be locked In the proper longitudinal adjusted position on the table, (preferably in the central position illustrated In Mgure 8, so that all of the ribs (33, 34, 36 and 37) may bear upon the upper table surface) and may be locked in place by nuts 52. Also, the auxiliary table is accurately jou-rnalled for rocking movement about an axis normal to the 6 be frictionally clamped to the main table, In anY desired angular position, as follows. ProJecting through a pair of openings 64 In the atudliary table and A pair of arcuate slots 65 in the pilot member, and having heads 66 seating In arcuate counter bores 67 in the pilot member, are a pair of bolts 68. Nuts 69 on the bolts are adapted to pull the table down into tight engagement with the main table, it being observed In 10 Mgure 10 that when the parts are puhed up tight a clearance 71 exists between the lower face 72 of recess 35 of the auxiliary table, and the upper surface of the pilot. The provision of this clearance prevents the pilot from holding the auxiliary 15 table with its bearing surfaces out of contact witb the main table, it being understood that only a few thousandths of an inch clearance is necessary, and that if desired the clearance may be decreased by the use of shims. In order to lo20 cate nuts 69 below the top surface 31 of the auxiliary table, they are prefera]Zly disposed in recesses 73 at opposite sides of the table. Secured to the front of the table adjacent front hold-down bolt 68, Is a scale plate 75 by means 25 of screws 76 having a reference line 77 cooperating with the graduations on cylindrical face -48 of the pilot member, it being understood that the holes In the plate are sufficiently oversize to permit the screws to be loosened and the plate ad30 justed by minor amounts in either direction to properly calibrate the machine, and w--en the adjustment has been obtained the screws are tightened to Permanently lock it in position. The auxiliary . table is accordingly rigidly 35 mounted upon the main w4r!c table, and by loosening nuts 69 the table may be rocked about the vertical asis of Pilot trunnion 62, the desired angular position being secured by bringing the appropriate graduation on scale 48 into allgnment 4o with the zero reference line on plate 75. When the proper adjustment has been obtained nuts 69 are tightened, it being observed that, by reason of the clearance between the underside of the table and the pilot member, tightening of the 46 nuts serves to directly pull the auxfliary table down into clamping engagement with the main table, with the bearing surfaces of ribs 33, 34, 36 and 37 in frictional locking engagement with the main table. The manner in which the tools or ro cutters are adapted to be mounted on centers and presented to the wheel will now be set forth. Referring Particularly to Flgures 7, 8 and 9, tailstock D is provi-'ded with a flat face adapted for sliding engagement with the upper surface C,6 of the auxiliary table, and is guided for movement along it by a pair of keys 81 secured in a longitudinal recess 82 in the tailstock by a pair of screws 83, one key being Iocated at each end of the tailstock. As seen in Figure 9a, keys 81 (10 project into the upper part of T-slot 32 and are snugly guided therein so as to maintain the tallstock square with the auxiliary table. The tailstock is adapted to be frictionally clamped to the upper side of the table by means or, of a single T-bolt 84, having a head seating in T-slot 32 of the auxiliary table, and a nut 85 bearing against the base of the tailstock. In order to line up the tallstock with the auxiliary table, it Is provided with a Pressure member 87 70 bearing against accurateiy formed -faces 88 and 89 on the tallstock and the table respectively, It being observed in Mgures 7 and 8 that, aside from the central break produced by front recess 73, surface 89 extends throughout the length of the table surface. The auxiliary ta-ble Is adapted to 75 table, so that pressure member 87 may cooperate
[2]7 with It in any desired longitudinauy adjusted position. A lug 91 Is also provided on the tailstock adjacent the Pressure member for preventIng it from tending to rotate and rock the tailstock out of firm engagem6nt with the table. The pressure member is held in place by means of a thumb screw 92 threaded onto a stud 93 secured in the tailstock base. it is accordingly apparent that the tamtock may be slid into any desired position along the table and when the desired position has been attained thumb screw 92 Is tightened, so as to cause the tailstock to be Pulled toward the front of the table. This action causes keys 81 to engage the front wall of T-slot 32, taking up any lost motion between the keys and the slot and accurately aligning the tailstocks with the longitudinal axis of the table by a "T-square" action. Nut 85 is then turned home td rigidly clamp th6 tallstock in place. Mounted for reciprocation in the upper end of the tailstock is a center 95, urged toward work gripping or loading position by a compression spring 96 seating against a cap 97 and adapted to be locked in place by a set screw 98. The center 95 is adapted to be retracted by means of an eccentric 99 seating in a transverse slot 101 in the center and carried by a shaft 102 having a reduced portion 103. The shaft is adapted to be locked in place by a set screw and lock nut assembly 104 having a reduced end seating in groove 103. The shaft is adapted to be rocked by means of a lever 105 secured to the end of the shaft. In the positions shown in Figure 8 the parts are in loading or work gripping position, and if desired screw 98 may be tightened to lock center 95. When it is desired to remove the work from the centtrs it is merely necessary to loosen screw 98 and rock handle 105 counterclockwise, which, through shaft 102, eccentric 99 and SlOt IO 1, retracts the center against the action of spring 96. A lubricant fitting 106 may be provided for admitting lubricant to the center and associated parts. The headstock is supported upon and secured to the auxiliary table in a manner similar to the tailstock, and therefore similar reference characters, with the subscript "c," have been employed to desi-nate the similar parts and they will not again I)e described. TI@.e headstock is provided with a simple cylindrical portion 108 in wwch a center 109 is adapted to be locked in longitudinally adjusted position by a set screw I I 1. Referring particularly to Figures 3, 4, 5 and 6, and referring first to lpigure 4, grinder frame 10 is provided with an end face disposed substantially normal to the axis of rotation of the wheel, designated as II 2 in Mgure 4, to which is seciired, Preferably by means of three screws II 3, a dual purpose foundation or frame member 114, having a pair of arcuate slots I 1 5 and I 1 6 at its upper end and a pair of lugs II 7 and i 18 at its lower end. The lugs are reinforced by angular webs II 9 and they are each provided with an opening 121 for receivlng a tooth-stop supporting screw, as will be pointed out hereinafter. Adapted for interchangeable installation in either slot 115 or slot 116 is a bolt assembly 122 carrying a short crank arm 123 terminating in a forivardly dire,.ted pn or shaft 124. As seen in Figure 3, bolt 122 i@ provided with a square head 125 seating in an elongated recess 12 6 in crank arm 123, so that nut 120 may be loosened and link 123 slid and rocked Into any desired Position with respect to bolt 122, and then lgcked in place. 2,429,250 8 Pin 124 Is preferably tightly fltted into link 123 so as to be non-rotatable therein and is adapted to interchangeably support any one of a plurality of wheel guards. This aPPreciably widens the r) scope of usefulness of the machine because it permits either cup, or dished or peripheral grinding - wheels of different diameters to be installed, as well as affords a wide range of adjustability of the guards with respect to the wheel, depending 10 upon the particular type of wheel guarding required by the work being handled. In Flgures 3 and 4 the guard of Mgures I and 2 is shown in place on the machine, in proper guarding relationship to the wheel. The giiard 15 comprises a guard portion 128 of generally semicylindrical form, having a front flange, and an ear 129 which freely fits over pin 124 and is adapted to be locked in place by a wing screw 13 1. Referring to Flgure 2, the parts are so adjusted 20 as to dispose guard 128 in comparatively close guarding relationship with wheel 17 and this relationship is also illustrated in Figure 13, In Figures 14 and 16, the guard has been removed and reversed end-for-end and reinstalled, with 25 the flange on the Inside of the wheel, to make room for the tool in the Particular grinding operation illustrated, it being understood that while lateral guarding of the wheel Is no longer present, the cylirldrical Portion of the guard is still eff ec30 tive to guard the operator. In Figures 5 and 6, the guard foundation assembly is illustrated having a modified guard 133 installed thereon. A lug 134 on the guard flts over pin 124 and is locked in place by a wing screw 35 135, it being observed that nut 120 has been loosened and link 123 rocked upwardly into the position shown, to compensate for the increased diameter of the wheel and guard. The parts are then locked in place to securely hold the guard 40 in operative position with respect to the wheel. Referring to Figure 17, guard 133 is shown in proper guarding relationship to a dished form of wheel 17a, it being observed that the guard fits down closely around the wheel and that the front 4r) flange adequateiy guards the operator. While any number of different size and type of guards may be provided for interchangeable installation on pin 124, the two guards shown have been found to take care of the various sizes and Eo types of wheels generally used, and by reason of the ready adjustability of the guard toward and away from the wheel to meet various grinding conditions, the reversibility of the guards and also tlie adjustability of the supporting arm, the wheel 55 may be efficiently guarded for all grinding operations. The invention also embodies a novel work stop device adapted to cooperate with the teeth or other Projections on the work and maintain it in (10 fixed angular relationship to the grinding wheel during the grinding operation, and yet permits ready indexilig. Referring particularly to Mgures 11, lla and 12, the device comprises a base member 14 1, hav(,5 ing a longitudinal slot 142 and terminating at one end in a head 143 having a pair of intersecting openings 144 and 145 which preferably are of the same diameter. A set screw 146 threaded into the head is adapted to lock a member placed In either 70 aperture. The base member is adapted to be secured in place on various parts of the machine by nieans of a T-bolt 147 and a nut 148. For instance in Figure 2 the base is secured to the face of the 75 auxiliary table by means of the bolt 147 seating
[3]2,429,250 9 In the T-slot 32, whfle in Ingure 13 the base member is secured to ear 117 of foundation member II 4, so that the work is movable with respect to It. Referrlng again to Mgure 11, cooperating with head 143 of the base is a rod 143 having an en:larged end providing a. transverse opening 151. R-od 149 may be mounted directly In opening 144 or 145 and locked In place by set screw 146. However, in handling certain classes of tool and cutter grinding, it is deilrable to offset the rod from the base and we have accordingly also provided a pin 152 having a head providing a'cross bore 153 of sufficient size to receive rod 145, and a threaded lower end 154. Rod 149 is adapted to be installed In bore 153 and pulled down into engagement with Vnotches 155 in a collar 156 by means of a nut 157 threaded on the reduced portion 154 of pin 152, It being observed that the shank of the pin Is of substazitially the same diameter as, openings 144 and 145, whereby It may be installed In either opening. In this Instance, however, it Is unnecessary to lock pin 152 in place with set. screw 146, as the frictional force set up by nut 157 is usuaby sumelent to frictionally lock the parts., Adapted to be inserted In opening 151 of rod 149, and locked in place by means of a set screw 158, is a rod 159 having a cross bore 161. Referring more particularly to Flgure 12, rod 159 is adapted to snugiy receive a thimble or sleeve 162 having a flange 163 Into which a screw 164 is threaded. Mounted for sliding movement in sleeve 162 is the threaded shank 165 of a stop finger supporting head 166, the shank having a longitudinal groove or keyway 167 cooperating with a reduced end 168 of screw 164 to restrain it against rotation within the thimble. Threaded onto the shank Is a nut 119, which bears against the upper face of flange 163 and Is adapted to thread the shank upwardly In the thimble, the shank being shown In Its lowermost position in Flgure 12. I-lead I 66 Is provided with a recess 171 and plvoted therein on a pin 172 is a finger supporting member 173. The flnger support Is urged In a clockwise direction by a spring 174, seating in recesses in the member and head 166, toward an adjustable stop screw 175 threaded into the head. Member 173 Is also adapted to be locked against rocking movement by means of a set screw 177 threaded into,head 166 and cooperating with a depression 178 In member 173. Member 173 is adapted to interchangeably support either the straight flnger 179 shown In Plgure 11, or the hooked finger 181 shown in Mgure Ila, the fingers being secured In place by a screw 182 threaded into the end of member 173. Taking up the grinding operations illustrated in the several perspective views, we have showix in each instance a spacer block 190 interposed between the head and talistock, and the auxibary table. Each block Is provided with a rib on its lower face adapted to seat in the T-slot of the auxiliary tabie and has a longitudinal slot In its upper face adapted to receive the head and tallstock keys. In this Instance pressure members 87 and 87c are mounted directly on the spacer blocks. While it Is to be understood that blocks 190 need only be employed when large diametered work is being handled, they majr, if desired, be left in place as permanent parts of the machine. Referring first to Mgure 2, the machine Is illustrated as having a simple hand reamer 191 mountio ial7 table being set on "zero" so as to move the. togi edges to be ground exactly parallel to the Path of tmvel of the main table; and the straight finger stop ITS Is shown as cooperating with the & teeth of the reamer for stepping It around as the grinding operation Proceeds. Stops 26 are so adJusted on rod 27 as to cause stop pin 28 to limit the travel of table 23 to that required to grind the tool. The head and ts%tock and spa-cer block as10 sembues are secured to the table py bolts somewhat longer than those shown in PYgures 8 and 9. In this Instance base member 141 is clamped directly to the top of the ai,xi"fary table by bolt 147 and rod 159 is clamped directly In opening 15 145 by means of@ set screw 146. The stop assembly is directly carried by rod 159 and is so oriented as to be stopped- by screw ITS when the flnger pivots toward the front of the machine, with the result that the opemtor, with each pas20 sage. of the work need only rotate the reamer an angular distance correspcinding to one tooth space, and during this "Inde)dng" operation the reamer wiU pivot the finger outwardly agajnst the action of spring 174 Into the proper position to stop the 25 next tooth or cutting edge in the proper grinding position. It Is to be understood that, if the work Is not Properly ground by single passage across the wheel face, handwheel 21 may be rotated to move slide table 19; work table 23; and 30 suxihary table B bodily toward the grinding wheel by the necessary distance to take off the - required amount of metal to restore the cutting edges of the tool. It Is to be understood that during grinding the operator will grasp the work and 35 urge It Into fim contact with the stop. I As Is well understood in the grinding art, it Is often desirable to cut with only a portion of the wheel face, the grinding face often being tilted from one-half to one degree from the plane of 40 the surface being ground, which prevents the back edge from dragging; eliminates any possibility of buming, and iesults In a much better Job. In the present machine this cocking or tiltihg of the wheel is effected by loosening the 45 bolt for the column and tuming the column through the required angle (usually from onehalf to one degree) to Incline the wheel face at a similar angle with respect to the Path of travel of the main table. 50 It sl@.ould be observed that In this particular setup of the tooth stop, neither rod 149 nor.pin 152 and lts.associated parts Is employed. The number of parts employed in any case will dePend upon the conditions of each setup, and .55 the.re is of course no hard and fast rule as to how they will be arranged. The Invention, however, In providing the novel assembly of parts Illustrated provides a sufficiently flexible assembly to meet any desired setup, it merely being necessary 60 to arrange them In the proper relationship to achieve the proper workstopping action. Referring to Mgures 1, 14, 15 and 16, we have Illustrated the machine setup to sharpen a side mflling cutter 193, having side cutting edges 194 65 and peripheral cutting edges 195 and 45' bevel corners 196, the parts belng shown in Flgures 15 and 16 In proper position to grind the 450 corners and In Plgures 1 and 14 In position to grind the peripheral edges 195. 70 Referring flrst to Flgures 1 and 14, the auxiilary table Is set on zero, f;o that It will move parallel to the plane of the wheel. Guard 128 has been removed and replaied in reversed position on shaft 124, and spacer ttlocks 190 are again used ed in place between centers 95 and 109; the auxil- 75 to raise the head and titjlstock the proper dis-
[4]tance to provide the required swing of the tool. Base member 141 of the finger stop assembly is secured directly upon the auxiliary table by means of bolt 147 and nut 148 and in this instance rod 159 is mounted directly in opening 145 of the base and locked therein by screw 146. Rod 159 carries thimble 162 of the stop assembly, and In this instance the hook form of stop I 8 I Is secured to carrier 173 in an inclined position, so as to lie directly under the tooth beirig ground. The head 166 is so disposed that arm 173 is freely pivotal toward the wheel, so that upon completion of the grinding of one face the tool may be rotated clockwise (Figure 14) to bring the next face Into grinding position, it being underst6od that in all of the grinding operations, the operator will exert sufficient pressure upon the tool to maintain the "stopped" tooth in firm engagement with the tooth stop, thereby predetermining the amount of metal the wheel will remove from each tooth. When all of the peripheral edges 195 have been sharpened in the manner just discussed, the parts are then brought into the relationship shown In Engures 15 and 16, as follows. The tOOl and mandrel are removed frorh the centers and reversed end-for-end, so as to incline the teeth upwardly adjacent the wheel; nuts 69 are loosened and the table rocked 45', as determined by the graduations on scale piate 75. It is also desirable to recombine the parts of the tooth lock device as follows. As seen in Figures 15 and 16, base 141 Is clamped to the auxiliary table In reversed ijosition from Flgure 14, and pin 152 is inserted in opening 145 in the base and rigidly clamps rod 159 by means of collar 156 and nut 157. Hook flnger 181 is inclined as before, but in this instance engages the top of the teeth as they are successively brought into grinding position and it Is accordingly necessary for the operator to exert a clockwise rotative force upon the tool during the grinding operation. When it Is desired to grind the tapered corner 196 on the other side of the cutter, it is merely necessary to rock the auxiliary table to its opposite 450 limiting position and to move the tooth stop finger assembly onto the other side of the tool. In Flgure 13 there is shown a helical cutting tool 201 carried by a mandrel 202 between the centers in, operative grinding relationship with wheel 17. In this setup of parts the auxiliary table is again set on zero, so as to travel exactly parallel with the cutting face of the wheel, but as the teeth 203 of the cutter are of helical form and must be rocked during grinding, a somewhat different stop arrangement is employed. Base member 141 is clamped to the underside of lug 117 of the guard foundation by means of bolt 147 and nut 148, so as to maintain the STOP assembly stationary while the work is being moved across the wheel face. Pin 152 is secured in vertical opening 144 in base 141 and is secured therein by nut 157. Rod 159 is located in openIng 153 of pln 152 and clamped against collar 156. Carried in opening 161 of rod 159 is a special form of tooth stop which consists of a plairi rod 204 held in position by set screw 160 and engages between the teeth of the cutter in such manner that when the auxiliary table is moved past the wheel the cutter will be rocked about the centers the necessary amount to maintain the surface to be ground in the proper relationship to the cutting face of the wheel, it being 2,429,250 12 sufficient rotative forces upon the tool to maintain it in engagement with stop 204. Indexing is accomplished by bringing the work beyond the tooth stop then re-engaging the stop 6 with the next tooth to be ground. In Figure 17 there is disclosed a forming t(>ol 205 carried by a mandrel 205 between the centers of the headstock and tailstock, and is adapted to be ground by a dish form of wheel 17a. In this 10 instance the auxihary table is again set on zero so as to carry the work in a path at right angles to the wheel axis and a re-arrangement of the parts of the stop mechanism is also utilized. The tool is provided with inclined tooth faces 207, and 15 In order to grind them properly a dish wheel is employed. Referring to the tooth rest or stop mechanism, base 141 is secured directly to the face of the auxihary table by bolt 147 and nut 148, and car20 ried by pin i52, inserted through opening 145 in the base, is rod 149. The latter in turn supports rod 159 to which the stop thimble 162 is secured. In this instance the straight stop finger 179 of ngure 11 is secured in place by screw 182 25 and engages d-irectly behind the tooth being sharpened, head 166 being so oriented that the flnger will freely pivot upwardly and allow a new tooth to be presented to the grinding wheel in response to indexing movement of the tool. 30 In Mgures 18 and 19 we have illustrated a modified form of head and tailstock also forming part of the invention. Referring first to fligure 18, the. base is of substantially the same form and is secured to the auxiliary table in a manner similar 35 to the tailstock previously described. As seen in F'igure 18, the headstock 212 is symmetrical in form, having an enlarged head portion 213 provided with a longitudinal bore 214 communicating with an opening 215. At each end of portion 4o 213 is provided an ear 216, and each ear is spht in a vertical plane by a milling cutter, the bottom of the cuts being indicated by the line 217. The I ears are provided with screws 218 for tightening the split portions and locking the center 219 in 45 adjusted axial position therein. In this instance the center is shown as made up of a major portion 219 of relatively inexpensive and. noncritical material and a hardened alloy insert 22 1, which forms the actual center. 50 Referring to Figure 19, the tailstock 223 is made from identically the same pattern and is basically the same in all respects, having an enlarged portion 224, a central bore 225 communicating with an opening 226, and at each end 55 is formed an ear 227, the ears being split by a milling operation aiong the lines 228. In this instance however center 229 is provided with a longitudinal groove 230 cooperating with a washer 231 to prevent rotation of the center (lo and yet permit free endwise movement. Center 229 is adapted to be locked in adjuste I d position by a cap screw 232 threaded into one ear 227, washer 231 being sufficiently thin as to not interfere with the clamping action. Center 65 229 is urged toward work gripping position by a compression spring 233 reacting against a cap 234 securely clamped in the tailstock by a screw 235 cooperating with the other pair of ears 227. The center is adapted to be retracted by a lod 70 236 projecting through cap 234 and threaded into the center. Cooperating with a lock nut and washer assembly 237 on the free end of rod 236 is the forked end 238 of a lever 239 which is pivoted on a pin 241 carried by a pair of supports understood that the operator will, as before, exert 75 242 formed on cap 234.
[5]2,420,280 in the fuuy released position shown in PU"e 19 the forked end of lever 239 lies against the rear face of cap 234, and, when it is desired to retract the eenter, a handle 243, secured to lever 239 is rocked downwardly, which causes the 5 forked end to move t.he center to the right, against the action of spring 233. .Tn Flgures 20 and 21 we have Illustrated a fine adjustment applied to the auxiliary table, which makes it possible to accurately adjust the table 10 to bring the tool Into correct allgnment the wheel even when extremely small angles are involved, without resort to tapping or other expedients. Provided on the Interior of the side webs of 15 the auxiliary @able both fiont and rear are bosses 251 and 252 Into which are threaded a pair of adjusting screws 253 and 264 respectively, which may be manually manipulated by cross pin handles or the like. The screws preferably Be in 20 a common horizontal plane closely adjacent the level of the top of main table 23, itnd cooperate with a stop 255 pivoted on a pin 256 carried by a slfde member 257. The latter :ftts into keyway 25 and has )shoulders 258 adapted to be forced 25 into tight engagement with the undersides of the overhanging portion of the keyway by a set screw 259 threaded into the slide and bearing against the bottom of the keyway. Stop 255 may be pivoted clockwise out of the path of screws 253 and 50 254 when it is desired to adjust the machine without them, or when the table is adjusted through angles which are too large to permit use of the adjusting screws. - Accordingl y, when It Is desire@ to employ the 35 flne adjustment, as for instance when grinding tapered reamers or other tools which may not be true, stop 255 is swung into its full line posftion; the table is adjusted into the approximate position desired; and the table T-bolt nuts 52 tight- 40 ened sufficiently to exert a frictional drag. Screw 253 or 254, depending upon the direction the table must be rocked, Is then screwed in. This causes the selecteci screw to engage the stop and force the table to turn about its axis against the re- 45 sistance of the frictional drag. When the adJustment.is complete, nuts 69 are tightened to rigidly lock the auxiliary table in place. In the drawings both screws have, for convenience, been shown engaged with the stop, but It is to be: 50 understood that in practice only one screw will be engaged, the other being backed off to allow the table.to turn. It Is also to be understood that while we prefer to employ a single stop, in combinatio n with front and rear screws, If de- r)5 sired, both screws may be mounted at the front of the table on opposite sides of the pivot and cooperate. with separate stops at opposite ends of the ta;ble, without departing from the spirit of the Invention. 60 In addition to permitting fine adjustnients to be carried out, the novel screw and stop assembly is also advantageous in many other classes of grinding as it makes it possible to set up the parts with the surface to be ground parallel to 65 the travel of the main table, irrespective of shape. From the foregoing detailed disclosure it Is apparent that the invention provides a ngvel auxiliary table which may be readily installed on the tables of present day surface grinders, 70 for the purpose of converting them to tool and cutter grinders, and which may be adjusted aboiit an axis normal to the table surface to locate the tool or cutter at the proper grinding angle, and also provides novel head and tailstock 75 14 assembues; a tooth rest or stop of novel construction; and guard and guard supporting assemblies which are so designed- as to permit a liumber of different guards to be Interchangeably mounted on the support and affords adJustment of the guards into various guarding positions with respect to the wheel, to permit various grinding operations to be carried out without interference from the guards, and at the same time affords maximum proteetion to the operaThe invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present em-bodiments are therefore to be considered in all respects as Blustrative and not restrictive, the -ecope of the Invention. being indicated by the appended claims rather than by the foregoing description, and. all changes which come within the meaming and range of equivalency. of the claims are ther.efore intended to be embraced therein. What Is claimed and desired to be secured by United States
