US2272088A

US2272088A - Roll grinder

Info

Publication number: US2272088A
Application number: US296032A
Authority: US
Inventors: Gunnar V Hultgren
Original assignee: Farrel Birmingham Co Inc
Current assignee: Farrel Birmingham Co Inc
Priority date: 1939-09-22
Filing date: 1939-09-22
Publication date: 1942-02-03
Anticipated expiration: 1959-02-03

Description

Feb. 3, 1942. G. v. HULTGREN ROLL GRINDER' Filled Sept. 22, 1939 4 6 Sheets-Sheet 1 ...Q Xi n,

Feb. 3, 1942. G. v. HULTGREN ROLL GRINDER Filed Sept.- 22, 1939 6A Sheets-Sheet 2 Feb. 3, 1942. G. v. HULTGREN ROLL GRINDER Filed Sept. 22, 1939 6 Sheets-Sheet 5 Feb. 3, 1942. AG. v. HULTGREN ROLL GRINDER Filed Sept. 22, 1959 6 Sheets-Sheet 4 Fell 3, 1942- G. v. HuL'rGRl-:N 2,272,088

' ROLL GRINDER Filed sept. 22, 1959 e sneaks-sheet 5 Patented Feb. 3, 1942 l uic-TED STATES* PATfENT'f'OFI-ICE g 2,212,038AV `uom.` Gnmnua t Gunnar V. Hultgren, Ansonia, `Conn.,`assig1ior to'A Fand-Birmingham Company, .Inc., Conn., a corporation oi' Connecticut n l Application september z2, 193s, serial No., 296,032

v V15 claim.'k This invention relates to improvements in roll4r grinders.

My new roll grinding machine is` particularly adapted for the grinding of large rolls such as steel mill rolls, and heavy shaiting.-V

Within recent years there has been an increas-, ing demand for the grinding of tapers on the roll f necks o journal sections of rolls, and also on the body or ends of heavy shafting. Various at. I

tempts have been made to accomplish this tapered grinding, andvarious difficulties havev been encountered. Grinders of the work-moving type have been built in which the carriage which carries the roll is made in two pieces, the separation being in a horizontal plane; the lower piece being constructed to` iit theways of the bed, the upper piece being attached to vthe lower so that it can be swiveled with respect to it, thearrangement being such that the upper half of the carriage, withthe-roll or shaft mounted thereon, could be set with its axis at an angle to the center line of the lower half. In this position, by traversing the entire yassembly in vi'ront of `the grinding Y wheel, a taper can be ground. However, in such 'a machine the carriage lacks rigidity, which is important for accuracy, unless the carriage is made very heavyv and cumbersome, and, more-'- over, in the grinding of long or steep tapers the upper half of the carriage hasvto be swung so far away from the center line of the lowercarriage section that the upper half overhangs, the lower half at the ends, and this further increases the conditions of unstability, as well as causing an` interference or prejudicial proximity between the upper half section and thesupport for the grinding element. y

Anothermachine which hasbeen used more recently is of the wheel-moving type having asupport for the roll which is fixed against longitudinal movement and beingfprovided with a back bed upon which are mounted two distinct wheel head'carriages, one of which ris used in grinding the body of the roll and the other of which has provisions for traversing the wheel head in an inclined directionfor grinding the taper on the neck of the roll.

essary either to have two distinct wheels and wheel heads, one on each carriage, or to transfer the wheel and wheel head from onecarriage'ltoi another, as required forr grinding the body and neck, respectively, of the roll.l i. n

It has also been proposed to grind the tapers of roll necks by providing a'geared connectionto v the in-feed of the grinding unit so that the grindf-Y Such a machine was quite expensive to build, and it was also nec- (ci. 51-49) .ing'wheel would be fed in at a uniform rate to form a taper.,

that as the wheel was no t positioned normally 5 -to the grinding surface, ,and owing to the Ispring wheel would grind infonly one direction of cut,

work, which obviouslyk "delayed the ratehof lngrinding. I 1 n One of the objects of the present invention is above-mentioned defects and ,drawbacks are eliminated. f y l5,v

the accuracy and `speed lof operation ing-'a machine Ior lgrinding heavy rolls and heavy shafting, 'in which it is possible to grindftapered Vsurfaces. zo

rolls and shafts. y, -k ,r f 2,5 To these and other ends' the invention consists to be hereinafter described and claimed..

In thev accompanying drawings: Fig. 1 is a plan view of a roll grinding machine 3,0 embodying my improvements;

Fig. 2 is afront elevation of the same: Fig. 3 is a partial plan view illustrating the Vmachine as adjustedior grindingthe neckof a roll;

right-hand end oi'Fig.-1; f t 4 Fig. 5is a plan View of the rear bed or base frame showing the mounting of the swivel base` thereon, certain parts being omitted;

Fig. 6y is a section on line 6 6 of Fig.` 2;' v Fig. 7 is a section on line 'I`-1 of Fig. 1; Fig.` 8 is a section on line 8-,8'01 Fig. '1;' Fig. 9 is'a section on line'S-S of Fig. 1; Fig. 10 is an end elevation of aportion of the machine showing the wheel unit lacked up oil! of the crowning device and in position to grind a roll neck; and

controlling the traverse motor for the'roll carriage and the traverse motor for thewheelhead;

also wasy open to serious practical objections, among which was the factl convenience ofro'peration, and also. toprovide a Y novel and improved method ofgrinding necked *Y in the novel features and combinations of parts Fig. 4 is an end elevation looking from ther Fig.` 11 isa diagram kshoiavir'ig lone means of` In usingy the machine shown-in the drawings 'theKV roll or other work is mounted in a carriage.

adapted to be traversed bymeans including 'an electric motor, along-abase-fram'e or bed, and' 5., past a grinding wheel mounted on a wheel head located at one side of the bed. In the operation of grinding the body of the roll or the like the roll is traversed andthe. wheel head held against movement in a4 direction lengthwise of the work. Upon conclusion of the grinding of the body of the roll or other work, however, it is possible to position the grinding wheel adjacent the roll neck or other part to be taper ground, and then, with the roll held against lengthwise movement, to traverse the wheel in an angular direction with respect to the work axis so as to grind the taper. These ends are achieved by providing, in association with the wheel head and a base frame for supporting the Wheel head, certain parts which permit the'wheel head to be traversed at an angle or set in xed position with'its axis parallel to the work axis.

In the drawings the work-supporting bed is.

shown at A, the work-supporting carriage at B, the headstock at C, the taiistock at D, and the work-rotating motor at E. These parts can ne of any suitable or preferred construction, and

the carriage B can be traversed by any suitable` means, for example, a shaft and gear drive generally indicated at F in Fig. 1, the traverse mechanism being operated from an electric motor G, arranged in this instance at the back of the machine. At the rear side of the machine is the grinding element-or wheel H driven in this case from motor I on wheel head J by means of a belt K. For traversing the wheel head an electric motor L is employed, and for feeding the wheel head rapidly toward or from the work an electric motor M is used.` 'I'he wheel head'J is supported from a base frame N of relatively short length arranged at the rear of the Workholding bed in the relation shown in Figs. 1 and 4, and a number of parts interposed between base N and wheel head J and operating in the manner hereinafter described permit the traversing of the wheel head at an angle to the work axis in grinding tapered roll necks and the like.v

The base frame N is provided with a vflat top 20 (Fig. 6) upon which rests a swivel base member 2| adapted to be arranged at different inclinations tothe work axis. This swivel base 2| is swiveled to member N to swing in a horizontal plane, the swivel point being adjacent the left-hand end of the base frame and the lefthand end of the swivel base (Fig. 7). The base frame and the swivel base in this particular embodiment are approximately co-extensive in length. In this particular case the swivel connection or pivot between them is provided by an annular flange 22 provided on a gear case 23 located in the base frame, said ange 22. occupying a round hole 24 in the lower web portion of the swivel base in the manner indicated in Fig. 7. It will be understood that by this arrangement the swivel base can be swung so as to lie parallel to the work axis or at an angle thereto. For clamping the swivel base in the adjusted position, two bolts 25 may be employed at the right-hand end of the swivel base (Fig. passing through slots 21 in the swivel base. It will also be seen from Fig. 5 that at the lefthand end of the swivel base a further clamping bolt 28 is provided, the same passing through a short slot 30 in the swivel base. By these vmeans the swivel base can be firmly locked in place after it has been adjusted to the desired position. Preferably the swivel base is moved to the desired position by applying pressure to the right-hand end thereof (Fig. 5), and the preferred adjusting and moving means comprises a threaded spindle 3| arranged in the base frame transversely thereof and occupying a groove 32 in said baseV frame, Vsaid spindle having a nut 33 threaded thereon, as best shown in Fig. 8, and said nut operating in the groove 32. This nut is provided with an upwardly projecting pin 34 entering a round hole in a bearing member or washer 35 set into the lower f ace of the swivel base. i This provides a pivotal connection between the nut 33 andthe swivel base. The nut preferably engages the central portion of the swivel base. The threaded spindle 3| has a head 3B projecting out of the base frame at the rear side of the latter, and by turning the head 38 by means of a wrench or the like the swivel base canv be swung onits pivot to the desired position. A Vernier lscale 31 enables a very exact adjustment to be made. This Vernier scale is preferably located adjacent the right-hand end of the swivel base (Fig. 5)

' On top of the swivel base 2| there is provided a longitudinally sliding table 33 adaptedvto be traversed along said swivel base. In the preferred construction the swivel b ase is provided on its upper surface with longitudinal V grooves 39 and 4D located adjacent the side margins of the swivel base, and the sliding table 3B is provided with corresponding V-shaped guide ribs 4| and 42 (Fig. 6) For traversing the sliding table a threaded spindle 43 is provided, this spindle being driven by suitable gearing from motor L, previously mentioned. This spindle is located substantially in the plane of the swivel base, as shown in Fig. 6, and is adapted to be engaged by a nut 44 depending from the sliding table 38, so that as the spindle 43 is rotated in one or the other direction, the sliding table will be shifted lengthwise either to the right or left. The usual or any desired provisions are employed for reversing the direction of movement of the sliding table when it reaches the limit of its travel in one direction, and as these are well known in the art I do not consider it necessary to refer to them further. Fig. 9 shows the nut 44 as being at the left-hand side of the sliding table, which is the preferred arrangement. 'I'he spindle 43 is provided with appropriate end bearings carried by the swivel base 2 I.

Above the sliding table 33 there is provided a sub-base 45, this sub-base supporting and guiding the grinding wheel head J, previously mentioned. The sub-base provides a pivotal mounting for the grinding wheel inasmuch as the subbase is mounted for movement in vertical planes relatively to a pivot adjacent the front or forward side of base frame N. 'I'his pivot is constituted by a pin or member 48 by means of which the sub-base adjacent its forward side is pivoted to the sliding table adjacent its forward side, as shown in Fig. 6.

The pivoted sub-base 45 is of utility in connection with the crowning or concaving of roll and other surfaces, the rear end of the sub-base being raised to move the grinding wheel in the direction of the work, and the lowering of the rear end of the sub-base being effective to move the grinding wheel away from the work. For

these purposes a suitable crowning device is proin detail) being eifective to` raise or lower av small sliding carriage I8 at the rear face ofthe base kmounted in lanti-friction bearings, 18 sup-4, ported in the vwalls of the -wheel head.' Between the bearings 58 and 1l a worm wheel 58 is fixed, is adapted to be rotated and this worm wheel by arworm |08 on a shaft |8| mounted transversely inthe head and driven by motor'M, previously mentioned, for the purpose of obtaining quick in-and-out adjustments ofthe wheel.'V This drive is larranged adjacent the rearl endy of the operation, and in order to do this I prefer to provide means. for raising the sub-baseand holding it at such an elevation that it will not be affected by the operation of the cam or disk .l1 and its associa-ted parts. In the'construction which I prefer a jack is interposed between the screw spindle 88.l Adjacent the frontend of saidv spindle" is a housing |82 rigid with the sub-base 4l and extending upwardly therefrom into the wheel head. andl the spindle 88 exu tends into this housing, where it has threaded' sliding table and the-fsub-base for separating them to the required extent, and this jack may.l

be a screw jack 5| carried by the sub-base adjacent the rear end thereof, and having a screw reacting against a portion of the` sliding table.

In the form shownwthe jack-comprisesa screw member 52, adapted to protrude at its lower end out of a rbushing 53 adjacent the lower face of I the sub-base,r the lower end of the screw 52 rest- Y ing on a hardened member` 5l setinto the .sliding table 88 at a point adjacent the rear margin of said sliding table. The jack screw 52 may be operated from a distance by suitable means, such asan adjusting spindle 55 having a headl 55 projecting out of the sub-base at one side of dle'to shiftA the 'wheel head in one direction orv the latter` and adapted to be engaged yby, a

wrench or the like. 'I'he spindle 55 is provided with a worm portion 51 engaging a worm wheel 58 having interior threads engaging the threads of the jack screw 52, and suitable means are-provided for Ataking up end thrust on the worm wheel 58. It will be obvious thatby this arrangement the turning of spindle in one or the other direction by the use .of a wrench ,or the:

like will be effective in rasing or loweringthe Y rear portion of the sub-base, provided the subbase vis in a` proper position for such action, and that by the means described the sub-base may at times be raised to such an extent and held at such `an elevation thatthe crowning 'device will no longer have any effect upon it.

The wheel head J is of the usual or any preferred construction. Itis guided on thesubtheA swivel base, and it will be noted that thev base for movement in a direction transverse or generally transverse to the work axis, s o that the wheel can be fed in and out. Preferably the guide means for the head includes a V-shaped rib 59 on thewheel head at one side thereof engaging the corresponding V, shaped` grooe 50 in: This is shown `in Fig; 7, and in.

the sub-base. that figure there` are also shown the side flanges 5|, which dependv from the sub-base and extend over and enclose the end portions ofthe sliding table and also act as guides 'I'he grindingwheel .motor I, previously mentioned, is provided with a base 52 mounted on thetop wall 53 of the wheel head adjacent the rear portion of the latter, and the motor base l52 is adjustable on the wheel rhead by meanssuch as;-an adjusting screw 54. At the front of the wheel head the shaft 55 of the grinding wheel has suitable bearingaand at one end the shaft 55 carries a pulley 55 (Fig. 1), engaged by the drive belt K;

The grinding wheel His enclosed in a suitable case 61, as usual.

The wheel head J vhas enclosed therein and fixed against longitudinal movement with respect thereto a feed spindle 58 (Fig. 6). At the rear portion of the wheelhead this spindle is17|i` engagement with asleeve |58 journaled in the housing in'anti-frictio'n bearings |04. Fixed to this sleeve |88 at the exterior thereofis a sleeve |85 carrying a worm gear 58. The worm gear 88 is adapted to be rotatedby ay worm 92, which isoperable from a -hand wheel at the front o'f lthe machine,k as hereinafter described.l Whenv the worm 82 is rotated, the sleeve |05 is turned to rotate theV threaded sleeve |03, the. latter f sleeve being in the nature of a nut, andas this nut is rotated andheld byhousing |52 in fixed relation to the sub-base, the nut moves the spinthe other by pushing or-pulling the rear end portion of the4 wheel head. When the motor -M is actuated for producing a quick feedingof the "wheeLthespindle 58 is rotated in one direction or ythe other, causing the spindle to bescrewed in or. out'in the nut so as to 'produce' a pull or push ofthe spindle onthe wheel head. e

For .the purpose of providing in-and-out or feeding vmovements of the grinding wheel by manipulation of a-device easilyaccessible by the operator at the front of the machine, regardlessv to rotatea beveled gear 15 on a vertical shafty 11. I'his shaft 11 and gears 15 and 15 are 1ocated "in the gear"casing"23, .previously mentioned,whoseflangel or cap 22 serves to swivel shaft 11 is co-incident with the axisof swiveling of the swivel base, so that rotation of shaft 11 can take place'regardless of the angular position of the-swivel base. At the upper end of the shaft 11vabove .the casing 28 and within the lines of the swivel base is vla beveled gear 18 engaging aibeveled gear 19 fixed to -a shaft 80 having end bearings 8| and 82 in` the` swivel base. It will be understood-'that this shaft l8|| can be rotated by manipulation of thelhand wheel 1|. f AThe shaft 80 is provided with a long spline 88, and v.this splineiits a groove in. a beveled gear 8l, which is slidable along shaft 80 and is :adapted to be rotated' thereby. The gear 84 table 88, f and 'for this purpose the `sliding table carries at its lowery parta sleeve 85, lheld inv place relatively to the sliding table'ebya bolt 85, the sleeve member .85 surrounding the shaft for a portion of 'its,length, and also surroundking a sleeve or hub 81-Ito which the beveled gear is attached, andthe arrangement is suchy that as the ending table :s is moved in either direction the gear 94 will be correspondingly moved while still rotatable by hand wheel 1I.

section. 90 to be rotated from section 59 irre spective of the vertical position of the sub-base and wheel head (within certain limits) relatively to the sliding table. Within the wheel head the shaft section 99 is provided with the worm 92, which upon being rotated in one or the other direction will move the wheel head inwardly or outwardly. Through the connections described this feeding in andout of the grinding wheel can be effected by an operator standing at the front of the machine and manipulating the hand wheel 1I, and this inward lor outward movement of the wheel head can take place regardless of the longitudinal position of the wheel head unit with respect to the swivel base.

In Fig. I have shown the sub-base and Wheel head in an elevated position such that the crowning device will -not be effective upon the sub-base. It will be noted that there is a substantial space between the roller 49 and the part 50. At the rear end of the sub-base the latter is provided with a switch-operating member 94 which may be in the form of a downward projection adapted to contact and operate a swinging switch arm or member 95 associated with a switch mechanism 95. This switch mechanism can be made in any of a number of different ways, and for the most part it is illustrated only diagrammatically in Figs. 10 and 11. The switch mechanism 96 is preferably attached to the sliding carriage 49 by means such as a bracket 91. Switch 95 controls the circuits of the work-traversing motor G and the wheelhead-traversing motor L. The arrangement should be such that these motors cannot be operated simultaneously, and the drawings illustrate one form of mechanism for this purpose. A spring 99 acts on the arm 95, and when the sub-base is raised, carrying the projection 94 upward, a circuit will be made for the wheelhead-traversing motor L, or at least the circuit of this motor will be closed at this point, whereas on the other hand it will be impossible -to operate the work-traversing motor because of its circuit being opened by the upward movement of the arm 95. It will also be understood that when the sub-base is lowered the arm 95 will be necessarily depressed to a position in whichthe work-traversing motor can be actuated and the head-traversing motor cannot be actuated. With the crowning device in cooperative association with the sub-base it is impossible to start the wheel-head-traversing motor. Upward movement of arm 95 beyond the position shown in Fig. 10 is prevented by a stop 95'.

As indicated by the dotted lines in Figs. 1 and ing rolls having tapered necks, I grind the body of the roll by traversing the work carriage with its roll past a grinding wheel or other grinding element which is nxed against movement in the direction of the work axis. While the body of the roll is being ground the swivel base 2| will be in an adjustment in whichit is parallel to the work axis. The motor G will have its circuit closed by the switch device shown in Figs. 10 and 11, and it will therefore be impossible for the wheel-head-traversing motor L to operate, and the wheel head will remain and be heldin a fixed position relatively to its supporting base frame N. In this operation spindle I9 and nut 44 will serve to hold and lock the wheel head fixedly in any longitudinal position to which it has prewiously beenmoved. If it be desired to crown the roll body, the crowning device will operate in the usual .manner and swing the sub-base on its pivot in such a manner as to give 4the roll body the desired contour.

Now when itis desired to grind a tapered neck on a roll, for example, one having the contour 2, the traversing means for the work carriage includes worms or like means which render the work carriage self-locking, so that when its movement is arrested in any position the carriage cannot be moved endwise in either direction by extraneous means. There is thus provided a means for locking the carriage against endwise movement when this is desired.

In accordance with my new method of grindshown in- Fig. 3, the first step is to move the roll carriage endwise by its traverse mechanism to a point where the neck portion of the roll is opposite the grinding wheel. When the work carriage comes to rest in this position it will be locked therein for the reason previously explained. The sub-base isthen jacked up by manipulation of the v.jack screw in the manner previously described. By this operation the opening of the circuit of the work-traversing motor will be automatically ei'i'ected, as previously described, because of the upward movement of the projection 94, permitting the lifting of the switch arm 95, and the head-traversing motor L will be permitted to operate because of the closing of the gap in its circuit. The swivel base is placed in the desired angular position for grinding the taper, and locked in that position. Then the traversing of the wheel head unit can be commenced, -and the wheel head will be moved to and fro to grind the taper, the grinding wheel being normal to the tapered surface and operating upon the work when the wheel is moved in both directions. After grinding one of the roll necks has been completed, the machine can be manipulated in an obvious way to move the other neck opposite the grinding wheel, and thereafter grind the taper of the other neck, the swivel base being set at the .proper angle for this purpose 'I'he machine can also be used for grinding tapers on large shafts, and shafts with large-diameter flanges can be accommodated in the machine. 'I'he device will taper equally well. in either direc'- tion. There is no back-lash or deection in the machine parts whichwill make grinding difficult and result in a poor grinding finish. The device can be set very accurately to give the required amount oi' taper without the use of additional adjustments of other units of the machine.

One of the important advantages brought about by my invention is that a roll with tapered necks can be finish-ground in the machine without disturbing the original setting of the roll. This will aid in bringing about a true roll and also cut down the grinding time. Another important advantage arises from the fact that the tapering attachment is controlled from the operator's position in front of the machine, the voperator while in vfront of the machine being able by manipulation of ahand wheel or the like to move the grinding wheel in or out as required. Another advantage arises from the fact that while, when 2,2v2,osav n reuirmng to straight body grinding nommersplit work table or carriage, where extreme accuracy 'in effecting this angular adjustment isv most important. s n j s It is also an advantage of my new machine that the same hand wheel for the in-feed of the grindingwheelisusedinthecaseofbodygrindingas in the case of tapering. 'I'he wheel can be moved to or away from the work during the traversing of the grinding wheel, although in kmost cases all feeding isdone at one end or the other of the stroke, at which time the grinding wheel unit is at a standstill.

By my invention the unit which is to be swiveled so as to provide for the grinding of a taper need be no longer thannecessary to grind the longest taper anticipated, which isl usually relatively short compared tothe work being ground. This greatly simpliiies the construction of the machine, and doesy away with the necessity o1' splitting the work-supporting carriage as it. has been split in previous machines ofthe work-moving type.' On the other hand, as compared to previous machines `of the wheel-moving type, the provision of two distinct wheel-moving carriages is no longer required, nor is it necessary to provide more than one wheel heador tomove .the wheel head from one carriage to another. that is required in addition to the work-holding bed and work-holding carriage is la relatively short back bed or base frame on which is mounted a wheel head adapted to be heldin a fixed position for body grinding and adapted to be trav-f ersed at an angle for taper grinding. Moreover, in operating the machine the transition vfrom body grinding to taper grinding, and vice versa. is easy and convenient.

While Il have described with particularity a preferred form of machine embodying my invention, it will be understood that the invention is susceptible of many and various embodiments. and that various modifications and changes in 3. In a roll grindingmachine, a work bed, a. work carriage. means for traversing the work carriageron the workbed, a back bed, a wheel unit thereon having a tiltable wheel, a crowning device `cooperating with the tiltable forrendering the crowning device vineffective to `control'the wheel, and means operable only when the crowning device is inoperative for traversing the wheel unit on the back bed. Y

4. In a roll grinding machine, a work bed, a work carriage, means forftraversing `the work carriage on the work bed, a back beda wheel unit thereon having a tiltable wheel, a crowning device cooperating with the` tiltable wheel, means for rendering the crowning device ineil'ective to Y control the yfwheel,` and means operative only when the crowning device land the work-traversing device are out offoperation fortraversing the wheel yunit on the backbed at anangle to the work axis. e

5.. In akroll grinding machine, a work bed, a

n work carriage, means ;for traversing, the work All the details may be made without departing from the yprinciples herein explained or the scope the claims.

What I claim is:

1. In a roll grinding machine, a work bed,'a

work carriage, means including van electric motor for traversing the work carriage, a back bed, a`

wheel unit on said back bed having a vertically shiftablewheel, means including an electric motor for traversing said wheel unit on said back bed along the work, and means insuring individual operation only of said motors and preventing their concurrent operation, said lastnamed means being controlled in its operation by the vertical position of the-grinding wheel.

2. In a roll grinding machine, the combination ofy a work bed, a work carriage, means including an electric motor for traversing the work carriage on the work bed, a wheel unit comprising a vercarriage on the work bed, a back bed, a grinding rwheel-uniton the back kbed including a sub-base pivoted toi move vertically, a crowning device associated with the back bed forcooperating with and supporting the sub-base so that Vthe work is ground with a crown, means for raising the sub-base and holding it-at such elevation vthat the crowning device is ineiective, and means for traversing :the grinding wheel unit on the back bed at anv angle to theaxis of the work. 6. A combined work-moving andV wheel-moving grinder havinga work carriage, a wheel carriag'e, electric motors vfor operating the respec-v tive carriages, means insuring the operation of each motor only when the other motor is inoperative, said machine having a crowning device, Ameans for rendering the crowning device inoperative, and means for preventing' operation of the wtliieel carriage whenv the crowning device is opera ve.

7. In a roll grinding machine, a work bed, a work carriage, means for traversing the work carriage on the work bed, a backibed, a wheel unit on the back bed adapted to belocked in place so as to remain stationary` while the work is traversed.- meansffor traversing the wheel unit at an angle to the work axis, and means for preventing ysuch traverse except when the work carriage traverse means is inoperative.

8. In a roll grinding machine, a work bed, a. work carriage, means for traversing .the work carnage, a short back bed, a swivel base mounted on the back bed to turn in a horizontal plane, a sliding table guided by the swivel base, a. sub-base pivoted to the sliding table to swing vertically, a wheell head mounted on the sub-base, and means for traversing the slidingtable.

9. In a roll grinding machine, a work bed, a

work carriage, means for traversing the work carriage, a short back` bed, a swivel base mounted on a `back bed to turn in a horizontal plane, a

tically swingable grinding wheel, a back bed on which said wheel unit is mounted, means including an electric motor for traversing said wheelunit on the back bed at an angie to they work axis, and a circuit-closing device for said motors controlled by the swinging of the grinding wheeland arranged so that when either of said motors operates the other is inoperative.

Vsliding table guided by the swivel base. a sub-base pivoted to the sliding table to swing vertically, a wheel head mounted on the sub-base, means for traversing the sliding table, a, crowning device associated with the back bed cooperating with the sub-base to lift the same, and means adapted to raise the sub-base out of cooperation with the crowning device so that the latter is ineiective.

d 10. In a roll grinding machines. wheel head movable toward and from the work. a bed in front of said head on which the work is mounted, means for ltraversing said head along thev work wheel, means' `unit traversing means is inoperative.

at any of various angles to the work axis, a transverse spindle associated with the wheel head for adjusting the same toward and from the work, means operating on the rear end portion of said spindle for effecting a power adjustment of the wheel head, and means operable on the front end portion of said spindle for manually adjusting the wheel head toward and from the work, said last-named -means having an operating member adjacent the iront portion of said bed, said two adjusting means being operative when said head is in different traversing positions. n

11,. In a roll grinding machine, the combination of a work bed, a work carriage thereon, means on said carriage for holding and rotating a roll, means for traversing the carriage along the bed, a back bed substantially parallel to said work bed, a grinding wheel unit on said back bed, and means for traversing said grinding wheel unit along the roll with the wheel axis at an angle to the roll axis only while the work carriage is stationary, said carriage traversing means on th'e other hand being operable only when said wheel 12; In a roll grinding machine, the combination of a work bed, a work carriage thereon,

l-means on said carriage for holding and rotating a roll, means -Iorltraversing the carriage along the bed, a back bed substantially parallel to said 'work bed', a grinding wheel unit on said back bed, and means for traversing said grinding wheel unit with the wheel axis at an angle tc the roll axis only while th'e work carriage is stationary, said back bed being a relatively short bed located between the ends of the work bed.

along th'e rollaavaoss Y 13. In a roll grinding machine, the combination of a work bed, a` Workv rriage thereon, means on said carriagey for holding and rotating a roll, means for traversing the carriage along the bed, a -back bed substantially 'parallel to said work bed, a grinding wheel unit on said back bed, and means for traversing said grinding wheel unit along the roll at an angle tothe roll axis while the work carriage is stationary, said wheelunit-traversing means being constructed so. that when arrested it locks the wheel unit in position for traverse of the roll past the wheel.

14. In a roll grinding machine, a workbed, a roll-holding carriage, a back bed, a wheel unit on said back bed `arranged to be locked in place on the back bed or to be traversed along the roll with the wheel axis at an angle to' the roll axis, means including an electric motor for traversing said roll-holding carriage on the work bed past the wh'eel unit, means inclu'ding an electric motor for traversing the wheel unit along the -roll at an angle to the roll axis, and means for preventing concurrent operation of said motors.

15. In a roll grinding machine, the combination of a work bed, a work carriage, means for traversing the carriage along the bed, a wheel unit comprising a vertically swingable grinding wheel, a crowning device associated with the work bed and cooperating with said wheel unit, a back bed on which said wheel unit is mounted, means for feeding the wheel unittoward and from the work, and means for traversing said wheel unit on the back bed at an angle to the work axis.

GUNNAR V. HULTGREN.