Патент USA US2118304код для вставки
May 24, l938. l -c. J. HERTLEIN - 2,118,304 GRINDING MACHINE Filed 001'.. 5, 1936 2 Sheets-Sheet 1 Wk ATTORNEYS _ May 24, 1938. ' c. J. HERTLEIN'- ì '. 2,M8,304 GRIND^1NG MACHINE Filed 001;.l 3, 1956 w â. . ¿Sheets-Sheet 2 .__ xNvENToR CARL J. HERTLEIN ATTORNEYS Patented May 24, 1938 2,118,304 UNITED STATES `rnfrlszfl-v'r OFFICE 2,118,304 GRINDING MACHINE .Carl J. «Hertleîm Brooklyn, N. Y., yassìgnor of `one-‘half to‘Franz Fuchs,1Br,ooklyn,.N.`Y. Application October 3, >25 Claims. The invention relates in general to ‘a grinding machine and specifically relates to thetcolfspin dle and to the .associated motor `drive -o'f such machines; lto the mechanism for shifting the v`5 grinding tool vertically and to anorganization of Fig. 4 is a view in `sideelevation showing the side opposite vto -that »shown A'in Fig. l1 and .with the upper portion .of the main -column ïbroken away-'to show parts-of the micrometer screw-feed; Fig. 5 >«is a horizontal sectional view >somewhat -5 control stops for limiting the travel ofthe -grind enlarged and taken on the plane indicated ~by ing tool. the line '5-5 of Figs. '1 -and 4; . The present application constitutes a'compan ion application to an adjustable work »'bed for :10 supporting the work acted upon by the =tool and associated mechanism herein disclosed‘and lwhich application is »entitled “Adjustable work’bedf”, 'Se rial No. 103,839 ñled October 3, >1936. The primary object-of the invention vis y.to fim ‘Fig.»6 is a `detailed vertical sectional -view taken on the plane indicated ¿by the line 6-’6 o‘f EFig-'5 looking in the-direction indicated byfthe arrow; $10 Iand Fig. '7 `'is a detailed >plane View of `the `stops shown kat Vthe-top of the carriage in Figs. l and-2. ‘In fthe drawings .there Ais shown 1a supporting r prove and simplify -grinding machines =so as to `Atank ‘I0 designed to holdthedrip lwater from the ‘15 provide among other things for both a coarse lfad justment and setting of the grinding tool at Aan yoperative working position, 'as rwell as a -»re’ñned micromical adjustment of z«the tool ‘as circum stances vmay indicate as desirable, »particularly in the control and presetting of the'limits olf move ment of the tool in its vertically «movable :direc ftion during the coarser movements. The invention has for'other objects the pro tool. Mounted on a bed plate I I therein are two 'large -uprights, a vmain column ‘il 2 :and a ‘ffnulcrum standard I3. Themain column comprises a rug ged casting including side fpla'tes »'I4 and VI5 con nected across their 'fronts lby a >face >plate 'I6 20 viding of easily fand quickly manipulated means for controlling the ‘belt tension between the tool spindle and the motor for driving Ithe same; fthe providing of means for quickly releasing the -'ten sion y'to facilitate shifting-of 'the belt; the -provid ing of stops for limiting the movement --o‘f the spindle, which stops can 'be quickly reset into `approximate 'limiting yposition ' and thereafter «more .accurately `»set to minutely'limit ‘the >desired. `path of travel I‘o'f-thegrinding tool. 'Various other objects and advantages of the 35 invention lwillbe in kpart obvious from an inspec 'tion of the >accompanying drawings and in ‘part will‘be vmore lfully set forth in the ‘following par ticular description of one '-form of grinding-ma .4 o chine embodying the invention-»andthe invention .also consists in certain new and novel "features of construction and »combination of parts ïhere yinafter `set ‘forth and claimed. vIn vthe accompanying drawings: Fig. '1 is a View largely >in side elevation and with a .small portion at the bottom Aof -the lcar riage broken away vto showthe lower plunger vstopand‘illustrating a lpreferred embodiment o'f the invention; Fig. 2 is a view 'largely in iront elevation 0f the 'right Vside of ‘the 'preceding -ligure fand Vpartly provided with rforwardly projecting Iand .vertically extending guideways 2|"I and il 8, land 'merging 'into a wide spreading lbase I9. ~Slidably mounted -'on .theLguideways :I-'I and vI8 is a vertically shiftable carriage '-20 » of greater width ¿than the face >plate I6 .and side flapping the forward-edge portion Aof the side plates vIII and I5. ‘I'he lcarriage .isien larged at its `‘lower portion to forma 4forwardly extending 'horizontal extension 2| for supporting the ' grinding :tool Aand associated parts. ‘The -eX Itension 2| iis relatively wide Yas shown in Fig. '-2 .andhas supported thereon aspindle quill '22 ’in vwhich is rotatably mounted »a tool spindle `<23 projecting from one end of the quill. A .grind ing tool l21! Iis‘replaceably mounted on -the‘end of the spindle 523 following conventional practices in this respect. The opposite end lportion -of the spindle> 'is provided with a driven multi-speed spindle pulley 25, the free end of »which'is `jour nalled in -a bearing 26. 40 The front "face vof the carriage ‘Z0 above vthe extension 2l »is also provided with vertical guide ways i211 in which is slidably mounted the basev plate 28 of -an electric motor 29. ’The .motor shaft 'is provided with a spindle pulley '30 `in »driving 45 'relation with -.pulley -25 by means of a belt "31. 'Tension is maintained-'on the'beltby means of a coiled spring 32 positioned between Vthe exten sion -2`| and the underside of .the 'bracket‘33 "be -tween'the `motor `-29 yand‘tl‘re sliding vbase plate '28 50 yin vertical section taken fon 'the plane indicated las :best shown in Fig. 4. Opposite ends >of ‘the spring 32 are maintained in vertical vposition 'by byxthe line 2-2 of Fig, f1; Fig. 3 isa rearelevational‘viewflooking‘at Fig. 1 a pair vof aligned spring guiding lingers 34 and y35, the lower ñnger 35 »being :threaded and -pro ~ _from the :right vside thereof; lvided Awith an >adjustable nut 36 :forming lan :ad- :55 2 2,118,304. justable bearing for the lower end of the spring. The motor and its associated base plate is lim ited in its upward movement by the set screw 31 carried by a stop plate 38 at the top of the carriage and with its lower end engaging in a cup 39 formed on top of the motor. The set screw is secured in its vertically adjusted posi engaged by a headed screw 8l controlled by lever 82 (see top of Fig. 5). Each stop is provided with an offset 83 threaded through which is a vertical screw 64 secured in its adjusted place by a bind "ing screw 55. In this way the vertical space be tween adjacent vertical screws of the pair of stops 55 and 51, for instance, may be accurately set first by roughly setting the stops on the main tion by means of a binding screw 4t. From this construction it is understood that the column and then adjusting the vertical screws. tension on the spring 32 is regulated by the Similarly, when it is desired to control the tool 10 manipulation of the nut 35 so as to cause the travel t0 the lower portion of the machine, the motor to bear upwardly against the screw 31 lower pair of stops 58 and 53 may be utilized which has been preset to give the desired tension and the space between their associated vertical screws may likewise be accurately defined and on the belt 3|. 15 ‘ For the purpose of releasing the tension on the located. Operating in this space'as suggested in Fig. 1 belt where it is desired lto shift the belt on its pulleys to obtain variation in speed, a plunger is a carriage stop 55 comprising a plunger 'w31 4I is caused to react between carriage and motor urged forwardly by a spring 58. The plunger to lower the motor against the resistance of the may be withdrawn into inoperative position> spring 32. The plunger is actuated by a lever against the tension of spring 58 by means of a 20 42 pivoted to a bracket 43 carried by the stop head 69 particularly shown at the lower portion plate 38 and to which the plunger is pivoted. of Fig. 1. The plunger is provided with a Ylock The lower end of the plunger is received in’l a, ing pin 10 which, when the plunger is with cup-like wear plate 44 similar to the cup 39 and drawn may be rotated into position to bear on the adjacent surface 1I of the carriage to hold 25 25 likewise formed integral with the motor base plate 28. ~ In order to permit the displacement of th motor from the carriage, the stop plateA 38 is ful crumed on a pivot pin 45 and arranged so that its free end 45 (see Fig. 7) normally held in place by a screw 45', may be moved forwardly about the pin 45 and swung out of the path ofthe base plate 28 and associated parts. In this way the motor can be slid upwardly until clear of the guideways and thus be removed from the car riage. ’ The carriage and with it the tool spindle and its driving motor may be moved up and down vertically as a single unit by means of a long, 40 forwardly extending, manually-actuated lever 41 provided intermediate its length with a fulcrum nut 48 adjustably mounted in a slot 49 formed in the fulcrum standaid I3 and which nut is se cured in adjusted position by means of a clamp 45 controlled by a handle 58. The inner end of the lever 41 terminates in a bearing wheel 5I which is in sliding and lifting engagement with a wear plate 52 formed on the underside of the motor bracket 33. The lever is provided at its 50 free end with a handle 53 and secured thereon between the handle and fulcrum is a counter weight 54 designed to balance substantially the weight of the motor carriage and associated Ver tically movable parts. 55 From this construction it is understood that the fulcrum of the manually actuated lever is adjusted vertically along the standard I3 so as to bring the tool 24 in the region of the work to be ground and with the fulcrum set in place the operator by manipulating the lever may cause the grinding tool to operate bodily in a vertical direction while being rotated by the motor. >For the purpose of providing limits to the per missible vertical movement of the carriage when so actuated grossly by the manipulation of the lever, adjustable stops are provided between the carriage and the main column. For this purpose there is shown in Figs. l and 5 a vertically ex tending channel plate 55 secured to the side plate I4. Vertically adjustable on the channel plate are two pairs of adjustable stationary stops num bered downwardly in Fig. l, 53 to 58. Referring to Fig. 5 it is noted that the stops are each se cured in their relatively adjustable position by 75 means of a binding nut 60 within the channel the carriage stop in its inoperative position. It is herein suggested that a second stop 12 of a similar plunger type be employed above the stop 66 and designed to operate between the upper pair of fixed stops 55 and 51 in those cases where 30 it is desired to operate the grinding tool at rela tively higher position off the base of the ma chine. In the showing in Fig. 1 the plunger of the upper stop 12 is withdrawn and locked in its inoperative position and thus has no control, for . the time being, on the possible movement of the carriage. Y Considering the showing in Fig. 1 with the low er carriage stop operative and the upper carriage stop inoperative, it is understood that, by lower `ing the lever handle from its horizontal position shown, the grinding tool may be elevated from its lowermost position, with plunger 51 engaging the top of the lowermost vertical screw into an ele vated position for a distance defined by the length of the space'between the adjacent ends of the vertical screws forming parts of the stops 58 and 59. In those cases where a more refined vertical ad justment of the tool spindleV and its associated 50 motor is desired, a micrometer lead screw feed maybe employed. Such a feed includes a vertical ly extending lead screw 13 mounted at opposite ends in bearings 14 and 15 formed in the main column. A graduated hand wheel 15 is posi L Ul tioned at the top of the machine and is con nected through a worm and gear drive 11 with the lead screw 13 to rotate the same over angles measured on the scale 18. This lead screw is designed to be connected at will with the carriage 60 by means of a split nut 19. The 'nut is formed of two halves which are mounted in a rectangular casing 88 encircling the lead screw. The two halves of the nut each include an outstanding top ñange 8l which overlaps shoulders 82 formed in a pair of end closures 83 of the casing 88 to per mit relative movement of the nut halves trans versely of the lead screw while holding the nut from movement in all other directions. Oppos ing springs 84 and 85 bear on the two halves of 70 the split nut and tend normally to force the nut into threaded engagement with the lead screw. The two parts of the split nut are arranged so as to be separated into their inoperative position, spaced from the lead screw by means of a pair 75 >2,1.1533304 of cams 8.6 -positioned between the two .halves 'of the nut and moved to and .from .operative posi ëti'onsibylmeansof a split «nut lever ril?! in .the -form The casing isl secured in a verti .cally adjustable 'positionfonfthe :carriage ."‘byîmeans Íofïa bindingfscrewllß "extending through a verti "cal-'slot 891m thecarriage. vThe screwfhasza'wide -'hea'dfßll engaging the :inner sidepf îthe :carriage on :opposite sides of the 'slot'a's more particularly shown in Figs. ‘5 xand ‘16. ' . :In .operation .and :assuming 7that v`the split `nut ás in its released, inoperative "position and vthat :it as .desired'to operate 'the ygrinding itool 'Within justmentr of :the stops, ïherein‘before described, the `inanipulation'of .the long .controlîlever :Will raise ‘or lower. the igrinding î-.tool within ithe ¿preset l»limits tof rtravel. Should it îbe desired «to workin atheup portion fof tthe :available space, for’instance, ..20 :the :lower carriage stop is '.withdrawn’into .fits-in operative :position sand :by >ite-'rotating >the yplung er 'controlling ythezupper fstop,1it .may be caused fto 'project “into vand thus .operate iin fthe space vbe tween .either the .upper or ëlower Hpairs -of stops. Should ‘it be .desired to set vthe :grinding tool so .as to fix .or substantiallygñxiniits axis of .-rota tion, thesplit nut .fleverfis fshiftedso -as to .render y‘its associated cams ¿inoperative ëa-nd Ithus, permit the proper plunger with .-the'proper .-.stop‘toget all of the similarly located areas ground alike. yIn this way one preset arrangement .of the stops permits the identical grinding of any number vof Vtools for which >the stops were Yinitially set. When operating in connection -.with the >work supporting and locating bed .plate featured :in the companion application -above identified, there 'is provided a precision grinding vmachine capable of accurately grinding lwork such as 4cutting tools of various'kinds and which in general is 'capable of accurately grinding a .multiplicity of 'different contoured surfaces. ‘ While there have been shown, described and pointed out'in the annexed claims, certain novel features of the invention, it will be understood that various omissions,~substitutions and'changes 'in the form `and details of the device‘illustrated and in its operation may be made -by those vskilled in the art without departing from the spirit of the invention. I claim: 1. In a grinding machine, the combination of a base provided with a main column and a 'ful crum standard, a carriage slidably mounted ïi‘or 25 vertical movement Von the column, >a -motor slid yably mounted for-vertical movement on the car riage, .a tool spindle journalled inthe lower por -theopposing spring'to move rthe split nut halves into engagement :with the lead screw, rafter’which, tion of the carriage vbeneath ltheemotor for rotary - lby the Amanipulation -of ïthe graduated 'hand-Wheel the spindle from -the-motor, va'spring between the carriage-and motor tending to elevate vthe motor Aon the carriage, a .stop :between the 'motor and carriage :for limiting the -upward movement ofthe .fat the .top of the .machina va 'reñned adjustment »in :the Vlocation .of the laxis of `the ygrinding tool .may be obtained. Asithis'micromical .adjustment .c'a'n'ibe‘ obtained :at .fany'position within Vthe per vmissible Avertical :limits'gof movement of the tool, l-it 1is possible Ito lquickly locatev the fgrinding v.tool in its approximate-'desired .position :by the rough coarse movement `.provided ¿by the .lever :and then by `moving .the split nut .organization 4into lfen g'agement with lthe lead 'screw at :any position V.whel-’e’the trough adjustment may have~ located .-it, a zreñned variation in 'tool -¿positions :may :be quickly attained. ' movement about a horizontal axis, .a belt 'driving `motor on .the carriage, ra lever "fulcrumed on ‘the 35 standard, having .a handle at one rend and at the other end engaging `beneath the motorto elevate the same together with >the ycarriage 'on the ,main column. 2. In a grinding machine, 'the'combination of av base provided vwith a main column, a carriage slidably mounted `for vertical movement on the column, a motor slidably mounted `for vertical movement on the carriagepa tool spindle >~jour nalled Vin the carriage Ábeneath the motor `for ro tary movement about Aa vhorizontal axis, a :belt :During the .course of operating :the machine and wherein it may be desirable to change fthe .speed voi” rotation >of -the .grinding tool ,' tension on .driving the spindle from Kthe motor, aspringg Abe âthe belt may be-quic'kly released simply :by :pulling . tween Ythe carriage and vrnotorvtending to elevate Vdown on the belt Élever, :the .belt Amay -be .shifted the motor on .the carriage, a vstop between Vthe «conventionally from .one to another -pair Vof .pul îleys, -and releasing ¿tension on'the plunger ¿permit ‘the elevating spring to restore tension on the-belt. 'Should the ybelt become too tight or itoo :loose iin practice, 'the adjusting screw-.at the '.top'of the --motor may ‘be unlocked from .its previous vset ting, reset and :relocked lin its reset position. By means of va ydevice Vsuch asis ¿herein dis closed, extremely refined accuracy .in setting v'the motor and carriage îfor limiting-theupward move- - ment lof the motor on the carriage, and control means for shifting the lassembly :including the motor and carriage Aon the main 'column .thereby to move the tool spindle vertically. 3. In a grinding machine, the combination of a vertically disposed column provided with a guide -Way, a -carriage mounted for 'sliding movement grinding tool and in moving 'it .to and from .any thereon, a'grinding tool spindle rotatably mount 'preset locations vmay be :obtained quickly, where ed in the carriage, a standard, a lever having yits 160 -quick shifting :is desired and ¿in :moving 'it :over > fulcrum adjustably mounted-in the standard, said minute and restricted distances ~maybe obtained lever being connected at one -end to the carriage ~-wherever accurate and :refined :work ‘is desired. to move thesame vertically/'inthe guideway, hav 'The stops ycontrolling'ìthe vertical -'adjustment ing its other end_provided‘with an actuating ¿han-Y dle and having a weight carried ’thereby between ofthe tool -maybe further .used :as .when grind ing .a number of tools which are similar vin that the handle and standardand tending to counter they contain‘a >number of diiferent areas ofthe weight the carriage and parts carried thereby. 4. In a‘grinding machine, `the combination of -a same v--conformatio-n. For instance, the'ñrst area may .be ground with the plunger -ß‘l limited Ain vertically disposed column .provided with'a guide -its movement in `one direction by-stop 45-9. yThe way, a carriage mounted for sliding movement second-area «with plunger '12, 'for instance, >is lim thereon, a grinding tool spindle :rotatably mount ited in one vdirection of movement by ystop :5-1; ‘ ed in the carriage, Va standard and a manually :the thirdarea again'using plunger-.651 Land limited actuated control lever .adjustably fulcrumed 4.to in one direction of movement by stop 58 and so the standard and operatively :connected V.to >,the 22,75 on. .In-general :all .that Tis necessary Eis toengage carriage to `move the Ítool spindle 'vertically rover 2,118,304 distances controlled by the location of the lever fulcrum. 5. In a grinding machine, the combination of a structural part of the machine, a tool spindle Vto act therethrough to lift the carriage with its associated tool spindle. 10. In a grinding tool, the combination of a mounted therein for rotary movement, a motor, a belted connection between the motor and spindle, a spring reacting between the motor and struc tural part for placing tension on the belted con nection, and means for regulating the tension placed on the belted connection. 6. In a grinding machine, the combination oi a vertically disposed main column provided with a guideway, a carriage slidably Vmounted for verti cal movement on the guideway, a tool spindle journalled in the carriage for rotary movement, an electric motor slidably mounted for vertical movement on the. carriage and provided with a multi-speed pulley in belted driving engagement with the spindle in all positions thereof, means for adjusting the location ci' the motor on the carriage thereby to set it relative tothe spindle and manually actuated means engaging the car riage for shifting the spindle and motor when so relatively adjusted, together vertically as a unit and a resilient support between the motor and carriage acting to maintain tension on the belt. 7. In a grinding machine, the combination of a carriage mounted for vertical movement, a grind ing spindle mounted for rotary movement in the 30 carriage and provided with a driving pulley, a motor guided for vertical movement on the car riage and provided with a pulley, a belt forming a driving connection between the motor and spin dle pulleys, a coiled spring located between the carriage and motor, tending to elevate the motor upwardly away from the spindle and thus place tension on the belt and adjustable means for limiting the elevating movement of the motor un der the tension from the spring. 8. In a grinding machine, the combination of a 40 carriage mounted for vertical movement, a grind ing spindle mounted for rotary movement in the carriage and provided with a driving pulley, a motor guided for vertical movement on the car 45 riage and provided with a pulley, a belt forming a driving connection between the motor and spin dle pulleys, a coiled spring located between the carriage and motor, tending to elevate the motor upwardly away from the spindle and thus place 50 tension on the belt and adjustable means for limiting the elevating movement of the motor un der the tension from the spring, and manually actuating means for lowering the motor against the tension of said spring to release the tension 55 on the belt and thus permit easy shifting of the belt on its pulleys. carriage 9. In amounted grindingfor machine, verticalthe movement, combination a grind of ing spindle mounted for rotary movement in the carriage and provided with a driving pulley, a motor guided for vertical movement on the car riage driving and connection provided between with a pulley, the motor a beltand forming spindle pulleys, a coiled spring located between the car 65 riage and motor, tending to elevatev the motor up wardly away from the spindle and thus place ten sion on the belt, means for limiting the elevating movement of the motor under the tension from the spring, manually actuating means for lower ing the motor against the tension of said spring to release the tension on the belt and thus per mit easy shifting of the belt on its pulleys, and manually actuated means for elevating the motor 75 and in causing the motor to bear against said stop spindle, a spindle quill therefore, a spindle pul ley in driving engagement with the spindle, a motor provided with a spindle pulley, a belted connection between the two pulleys and a spring between the quill and motor, tending to support the motor from the quill and reacting between the spindle and motor tending to place the belt under tension, and an adjustable stop for one end of the spring for varying the tension of the spring and thus >varying the tension of the belt. 1l. In a grinding machine, the combination of a carriage, a spindle quill carried thereby, a 15 spindle rotatably mounted in the quill, a spindle pulley journalled in the carriage and in driving engagement with the spindle, a motor mounted for vertical movement, a motor pulley, a belt connecting the two pulleys, a spring engaging the 20 motor and urging the same upwardly against the tension of the spindle pulley, means for vary ing the tension of the spring, a stop for limiting the upward movement of the motor, and a plung er reacting between the carriage. and motor to' 25 lower the motor against the spring tension thereby to release the tension on the belt. 12. In a grinding machine, the combination of a carriage, a spindle quill carried thereby, a spin dle rotatably mounted in the quill, a spindle pul 30 ley journalled in the carriage and in driving en gagement with the spindle, a motor mounted for vertical movement, a motor pulley, a belt con necting the twol pulleys,V a spring engaging the motor and urging the same upwardly against the 35 tension of the spindle pulley, means for varying the tension of the spring and an adjustable screw stop for limiting the upward movement of the motor, a plunger reacting between the carriage and motor to lower the moto-r against the spring 40 tension thereby to release the tension on the belt, and said plunger and adjustable stops mounted to be shifted into an inoperative position clear of the path of upward movement of the motor, thereby to permit the motor to be lifted off the 45 carriage. ' ‘ ’ 13. In a grinding machine, the combination of a main column provided with a pair of vertically adjustable and relatively stationary stops, a tool supporting carriage mounted on the column for vertical movement, said carriage provided with a stop operable between the pair of stationary stops to limit the vertical movement of the car riage in both directions and means for raising and lowering the carriage, and said carriage stop con stituting a spring pressed plunger adapted to be retracted into .an inoperative position free of the stationary stops. ' 14. In a grinding machine, the combination of a grinding tool supporting carriage guided for 60 vertical movement, two means each operatively connected to the carriage to shift it vertically in dependently of the other.' one of said means com prising a manually actuated lever for quick shift ing into an approximately correct position and 65 theothercomprisingamanually actuated microm eter lead screw for refined adjustment of the carriage into the desired correct position and con trol means for connecting and disconnecting said lead screw from the carriage at will and resist 70 ing actuation by the lever when connecting the lead screw with the carriage and said lever per mitting actuation of the carriage by the lead screw. 15. In a grinding machine, the combinationV of 75 2,118,304 a mainïcolumn, a carriagemounted’thereon for vertical movement, a grindingtool mounted :for rotary movement in thecarriage, mechanism for shifting vthe carriage and withçit the grindingtool a column provided with two pairs of vertically adjustable vand `relatively stationary stops, _a tool supporting carriage mounted on the column for vertical-movement, ksaid vcarriage provided >with two stops, one for each pair 'of stationary stops and/each arranged for limiting,V the vertical `move ment of the carriage in both directions when vertically on the column, said mechanism includ ing la 4vertically yextending lead screw mounted in the column, manually actuated means for ro tating the -lead screw, a two-part split nut‘ located between its associated stationary stops mounted in the carriage and adapted to engage the lead screw whereby the rotation of the lead screw will shift the carriage vertically, means in cluding a vertical slot in the carriage and a bind ing screw carried by the nut and extending through the slot for adjustably securing the split 15 nut to the carriage at any position along the length of the lead screw, and control means for moving the two parts of the split nut to and from their operative engagement with op 20 posite sides of the lead screw. 16. In a grinding machine, the combination of a grinding tool, mounted for rotary movement about its axis and for shifting the tool vertical ly, a support for said tool, manually controlled mechanism for minutely shifting the support and 25 with it the grinding tool into a desired position, said mechanism including a vertically extending lead screw mounted for rotary movement and otherwise fixed relative to the support, a split nut for engaging the feed screw, a casing for the 30 split nut provided with means for securing the split nut to the tool support in vertically adjusted position relative to» both the support and the lead and each carriage stop movable into an inoper ative, out of the way position whereby either of l0 the two sets of stops may be utilized at will to control the limits of permissible movement of the carriage. 21. In a grinding machine, the combination of a main column, a carriage slidably mounted on 15 the column for vertical movement, a grinding tool journalled in the carriage for rotary move ment about- an axis iixed relative to the carriage, means including adjustable stops acting between the carriage and column for limiting the extent 20 of and for locating the permissible location of travel of the carriage and thus of the tool axis, manually actuated means for quickly and roughly locating the carriage to bring the tool axis ap proximately into a desired position and manually 25 actuated micrometrical feed means acting on the carriage when so roughly located to bring the tool axis more accurately into the desired position. 22. In a grinding machine, the combination of 30 a main column, a carriage slidably mounted thereon for vertical movement, a grinding tool journalled screw and resilient means between the casing on the carriage for rotary movement, a channel and split nut tending to maintain the nut in plate carried by the column, a plurality of stops 35 engagement with the lead screw. vlocated on the channel plate, means for adjust 35 17. In a grinding machine, the combination of ing the stops relative to each other, means for a grinding tool journalled for rotary movement locking the stops in their adjusted positions, a about a horizontal axis, a ñat plate constituting set screw carried by each stop, means for locking a vertically shiftable carriage for supporting the each set screw to its associated stop and a man 40 same, a manually actuated lever for shifting the ually actuated retractable stop carried by the carriage vertically, a lead screw and split nut carriage and disposed when in operable position 40 organization for shifting the carriage vertical between a pair of said set screws and disposed ly, said organization including a casing, means when in an inoperative position clear of the for detachably securing the casing to the car stops on the channel plate. riage at will, a two-part split nut slidably mount 23. In a grinding machine, the combination of ed in the casing, means tending to cause the two .a main column, a carriage slidably mounted parts of the nut to engage the lead screw and thereon for vertical movement, a -grinding tool control means for moving the split nut from its journalled for rotary movement on the carriage operative engagement with the lead screw. and movable vertically therewith, means for con 18. In a grinding machine, the combination of trolling the limits of movement of the grinding 50 a carriage mounted for vertical movement, a tool while operating in two zones of movement, 50 grinding spindle mounted for rotary movement said means comprising a channel plate carried in the carriage and provided with a driving pul by the column, four relatively stationary stops ley, a motor guided for vertical movement on the slidably mounted on the channel plate, one above 55 carriage and provided with a pulley, a belt form the other, means for securing each stop to the ing a driving connection between the motor and channel plate, each stop provided with a set screw 55 spindle pulleys and a coiled spring located be and with the two upper and the two lower set tween the carriage and motor for resiliently sup screws facing each other to form two adjustable porting the motor from the carriage and means space deñning means, the carriage provided with 60 for adjusting the tension on the spring thereby two retractable stops, one spaced above the other 60 to regulate the tension on the belt. and both adapted to operate in either of the 19. In a grinding machine, the combination of spaces defined by the upper or lower pairs of a main column provided with a pair of vertically relatively fixed stops whereby with one setting adjustable and relatively stationary stops, a tool of the relatively fixed stops the carriage may be 65 supporting carriage mounted on the column'for operated selectively in either a high or a low zone 65 vertical movement, said carriage provided with a of operation. stop operable between the pair of stationary stops 24. In a grinding machine, the combination of to limit the vertical movement of the carriage in a carriage mounted for vertical movement, a both directions and the stop on the carriage in grinding tool journalled for rotary movement on 70 cluding a spring pressed element disposed nor the carriage and movable vertically therewith, a mally in line between the pair of stops on the motor for driving the tool provided with a base 70 column and said element adapted to be with slidably mounted on the carriage for vertical drawn from said path to permit the carriage to movement, an adjustable stop between the car be moved independently of the stops. riage and motor base for locating the motor in a 75 20. In a grinding machine, the combination of preset position on the carriage and means react 75 6 2,118,304 ing between the motor base land carriage for forcing the motor into said position prefixed by the adjustment of the stops. 25. In a grinding machine, the combination of a carriage mounted for Vertical movement, a grinding tool journalled for rotary movement on the carriage and movable vertically there with, a motor for driving the tool provided with a base slidably mounted kon the carriage for ver tical movement and'an adjustable stop between the carriage and motor base for locating the motor in a preset position on the carriage, said stop being movable into an inoperative position to permit the motor and its base to be slid ofi the carriage. CARL J. HERTLEIN.