US1483748A

US1483748A - Grinding machine

Info

Publication number: US1483748A
Application number: US400150A
Authority: US
Inventors: Francis C Sanford
Original assignee: Individual
Current assignee: Individual
Priority date: 1920-07-30
Filing date: 1920-07-30
Publication date: 1924-02-12
Anticipated expiration: 1941-02-12

Description

Feb. 12 1 924. 1,483,748

F. c. SANFORD GRINDING MACHINE Filed July 30. 1920 6 Sheets-Sheet l Jnwnioz =k MM Feb. 12 1924.

F. C. SANFORD GRINDING MACHINE Filed July 30. 1920 6 Sheets-Sheet 2 d z u n w 14 a u .r w l e .r u m a a u a 1 3 5 m a m .w V N m a Vl/l/ r E m Feb. 1

1,483,748 F. C. SANFORD GRINDING MACHINE Filed July 30. 1920 6 Sheets-Sheet 5 Xx HI gnuc 1 x 4'01 franc/Is GSmgflmi Feb. 12 1924. 1,483,748

F. c. SANFORD GRINDING MACHINE Filed July 30. 1920 6 Sheets-Sheet 4 Feb. 12 1924.

F. C. SANFO IID GRINDING MACHINE 6 Sheets-Sheet 5 Filed July 30.

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g I I I I I I I I I I I I I I I y l/IIIIIIIII II IIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIIII Feb. 12 1924. 1,483,748

F. c. SANFORD GRINDING MACHINE Filed July 30. 1920 6 Sheets-Sheet 6 -lllllllH -llllllll I V/////////////AY/////// Patented Feb. 12, 1924.

FRANCIS O. SANFORD, O! BBIDGEPORT, COli'NIE'I-IGUT.

GRINDING MACHINE.

Application filed July 80, 1920. Serial No. 400,150.

fication.

This invention pertains to that class of.

grinding machines known to the trade as centerless grinders, because the body to be ground is not carried u 11 centers in a chuck or similar holder w ile being operated upon.

The machine is designed for precision work and, more especial] for g inding to true cylindrical form and to predetermined gage, bodies such as rollers for antifriction hearings and for like uses, requiring great 2 accuracy of form and dimensions, and uniformity of product.

The objects sought are to produce a highl efficient machine of the class noted, w ic shall be simple in construction, adjustment,

' and operation, durable, and of as small first cost, and as low maintenance expense, as consistent with the efiiciency required. These objects I attain by the construction illustrated in the accompanying drawings, which no show the best embodiment of my invention now known to me, though it is to be understood that variations 0 the structure may be made within the scope of the invention, and as may be required or suggested by different conditions of use.

In these drawings:

Figure 1 is a top plan view of the machine, partly broken away;

Fig. 2, a longitudinal vertical sectional view on the line 2-2 of Fig. 1, the base of the machine being represented as cut down to bring the working parts within the available space on the sheet;

Fig. 3, a transverse vertical section on the line 3-3 of Fig. 1, with the base similarly cut" down;

Figs. 4 and 5, sectional detail views of one form of automatic clutching and releasing device'for the driving pulley by which the to governing and feeding wheel is normally driven;

Fig. 6, a partial plan view of the machine, partly in section to show the springs employed to maintain the adjustable governmg and feeding wheel yieldingly in contact 65 with the work;

Fig. 7, a sectional elevation on the line H of Fig. 6, illustrating the work support and the friction device employed to revent vibration, chattering, or lack of uni ormity of movement of the governing and feeding wheel;

Fig. 8, a vertical section on the line b--b of Fig. 6 (but with the yoke-supporting head compete instead of cut away as in said Fig. 6), illustrating the manner of mounting and adjusting the yoke by which the shaft of the governing and feeding wheel is carried;

Fig. 9, a vertical section on the line 4-4 of Fi 1 to the shaft or arbor of the grindwhee which latter is not in section,

Figs. 10, 11 and 12, detail views of one of the sleeves or bearin s in which the main or grinding-wheel she t turns;

Fi 13, a front face view of the yoke whic carries the governing-wheel shaft or arbor and its bearings, the arms of the yoke being shown in section;

Fig. 14, a perspective view of the work so so port and guide;

ig. 15, a fragmentary view illustratin the device for dressing and truing the grind ing and governing wheels;

Fig. 16, a perspective view of the wheeltruing and dressing device mounted upon the work support and guide;

Fig. 1 a sectional view of the wheel, nut and screw employed to adjust the verning and feeding wheel toward and rom the grinding wheel; and a Fig. 18, a diagrammatic view showing location of the axis about which the governing and feeding wheel is" oscillated or adjusted, to give its axis the desired obliquity.

Main frame of the machine-1n these drawings, the machine will be seen to comprise a main frame of hollow or box construction, here shown as consisting of a base 1 and an up r section 2, the latter having a horizonta bed or table 3 and a well 4 to receive the water which is supplied to and flows Qii the work and the rinding and the governin and feeding wheels, which are peripherall y opposed or in tandem relation. The twopart construction of the box-like frame renders easier the molding and casting thereof, and the meeting flanges of the two parts which are bolted together or otherwise firmly united, add to the rigidity of the structure. Rising from the upper section 2 of the frame are two substantial posts or gillow blocks 5, in each of which is mounte a sleeve 6 of brass or other suitable alloy or metal, the two forming bearings for a shaft or arbor 7 which carries the grindin wheel 8. As seen in Figs. 9 and 11, the s eeves 6 are of tapering or conical form, to fit'correspondlng seats in the pillow blocks or in the top sections 9 thereof, which are preferably made se arate from the base portions 5 of said illow blocks, and are secured theretoby eavy bolts 10. This construction facilitates the taper boring of the top sections 9 of the blocks.

The sleeves 6, after being turned to proper taper and externally threaded at their smaller ends, are Ion itudinally slitted at one side as shown at 11 igs. 10 and 11), to permit of contraction to compensate for wear. Such contraction is effected and the sleeves are securely retained in place, by screwing a nut 12 onto the threaded smaller end of each sleeve, the nut bearing against the outer face of top section 9 of the pillow block or post 5 which carries the sleeve. To prevent turning of the sleeves in their seats, each is held by a key 13 seated 1partly in the top section 9 of the illow bloc and partly in the outer face of the sleeve, as seen in Figs. 9 and 10.

The shaft or arbor 7 is preferably left of full diameter from the outer end of one sleeve to the outer end of the other, but is slightly reduced beyond those points, and at the end remote from the grinding wheel is threaded as shown at 14, to receive a cap nut 15 and jamb-nut 16, said cap nut serving to cover the nut 12 and by bearing a ainst the sleeve 6 and nut 12, preventing ongitudinal movement of the shaft or arbor 7 to the left as viewed in Fig. 9. At a point between the sleeves 6 there is mounted on the shaft or arbor 7 a belt pulley 17, which is represented as held in place by binding screws 18, for which any other usual pulley fastening may be substituted.

Gfiudz'ng wheel and mountings. The grinding wheel 8 is carried, centered. and rigidly held in a divided metallic clamp or head comprising two main

annular members

19, 20, formed respectively with circumferential inturned flanges 21 between which the grinding wheel is clamped. The member 19 is formed with a sleeve 22, bored to make a close fit upon the reduced end of the shaft or arbor 7, on which it is held by a key 23 and also by a pin 24 passing transversely through 1,4aa,14a

the sleeve and said shaft, the purpose of the pin being to reclude movement of the sleeve longitudinal y of the shaft, while the key effectively prevents rotation of the sleeve and member 19 independently of or relatively to the shaft. The member 20 of the grindingwheel carrier is provided with a somewhat shorter sleeve 25, of larger diameter than the sleeve 22 and internally threaded to screw upon the external thread of said sleeve 22. By tightly screwing the outer member 20 upon the member 19, the flanges 21 of said

members

19 and 20 are caused to firmly grasp and securely hold the annular grinder or wheel 8 between them. To prevent accidental separation or loosening of the

members

19 and 20 of the grinding-wheel carrier, a jamb-nut 26 is screwed upon the sleeve 22 outside or back of the member 20, and turned firmlty up against the same. The radial web 27 o the member 19 of the grinding-wheel carrier abutting against the outer end of sleeve 6 and its nut 12, precludes longitudinal movement of the shaft or arbor 7 to the right as viewed in Fig. 9.

It will thus be seen that the shaft 7, which in practice is of quite large diameter, turns in sleeves or bearin s which may at all times be made to fit the sl aft snugly and as closely as is consistent with proper turning freedom, but without the possibility of play either axially or radially to the axis. This rigid supporting of the grinding-wheel arbor is a matter of great importance in a machine of this character, and articularly so where the machine is intended for precision work.

The annular grinding wheel 8 is carefully trued both as to its central eye and its circumference, the eye being made of a diam eter to fit snugly the annular rims of the clamping

members

19, 20. so that when said wheel is clamped by said members it will run true and in perfect balance. thus avoiding the vibration which might otherwise be produced and which would tend to chattering of the work in its travel through the machine. It will be noted that the grinding wheel, which in practice is advisably made of materially greater diameter than the governing and feeding wheel, is not mounted for adjustment, either toward and from the governing and feeding wheel, laterally, or otherwise.

Go'vemz'ng' and feeding wheel mm) mount inga-Go-operating and substantially in plane with the grinding wheel 8 is a governing and feeding wheel 28, which is likewise of annular form, and is clamped between

disks

29 and 30 carried by a spindle or arbor 31, as best seen in Fig. 3. This spindle or arbor is furnished with a collar 32. which forms an abutment for the disk 30 and itself abuts against one of the boxes or bears 33 in which the opposite ends or jourin na s of said spindle are carried. The bearings 33 are preferably slitted longitudinally on one side,the lower side as shown in Fig. 3-and provided 'with bolts 33 by which they may be slightly contracted to effect a close fit or tight contact with the journals of spindle 31, or to compensate for wear of spindle or bearings. it being of peculiar importance in a precision grinder of the centerless type that all lost motion or play of the spindles or arbors and consequently of the grinding and the governing and feeding wheels, be avoided or reduced to the practical minimum.

The disk 30 is advisably keyed upon the s indle 31, to prevent independent rotation t ereof and better to insure the non-rotation of the governing and feeding wheel 28 upon or independently of said arbor or spindle. The clamping

disks

29 and 30 are firmly pressed into and held in binding engagement with said governing wheel by a heavy nut 34 screwed upon the spindle 31. The bearin s 33 for the arbor or spindle 31 are forme upon or carried by a yoke 35 of the form best shown in Figs. 1, 6 and 13, said yoke comprising a vertical plate 36 of annuar form having laterally projecting arms 37 and extensions 38 which may be integral with the arms 37 or, as shown in Figs. 1 and 6, may be bolted to said arms. This latter construction is in some respects dcci'ncd preferable. as a matter of convenience in manufacturing and assembling the machine. The annular portion 36 of the yoke encircles and snugly fits a circular boss 39 formed on the upright face of a hollow supporting head 40, said head being formed upon or rigidly secured to a sliding carriage 41 movable upon ways on the table 3 of the main frame of the machine.

The purpose of, thus mounting the yoke 35 is to permit it to be rocked or tipped so as to place the axis of spindle or arbor 31 and its bearing in horizontal plane or in a plane oblique to the'horizon, as may be required. When it is desired to effect an automatic axial feed or traverse of the object being ground, the yoke 35 is rocked or tipped more or less about the axis of the boss 39 to set the axis of spindle or arbor 31 more or less oblique to the horizon, assuming that the centers of the two

wheels

8 and 28 are normally in common horizontalplane, as preterably they will be. To permit such adjustment of the yoke 35 when required and to hold the same rigidly against movement after proper adjustment has been effected. the annular plate 36 of said yoke is provided with curved slots 42 concentric with the axis of the boss 39. and bolts 43 are passed through the slots and into or through openings in the supporting head 40. the inner ends being provided with nuts 44 which being duly tightened. clamp the parts rigidl together.

Work-rest; three-paint support-45 indicates a main work-rest sup ort having two sections 45' and 45" of like orm and height, made fast to or integral with a connecting plate or bar 46 and spaced the grinding and the governing and feeding wheels to stand between them, as seen in Figs. 1. 6 and 14-. Each section 45' and 45 is in the form of a small stool having in its upper face a slot or groove 47 to receive a cylindrical rod or bar 48, which in practice is made of steel and tempered quite hard to resist wear, and is of a diameter to fit somewhat freely in the groove 47. The bar 48 is clamped and held in said groove by horizontal set screws 49, seated in tapped holes in the support 45, hearing at their inner ends againstthe bar 48 and serving to press and hold the same firmly in contact with one of the walls of the groove 47. The cylindrical form of the rod 48 permits the same to be made perfectly true by turning in a lathe or by grinding, and presents only a line contact with the work which it supports; hence permits the work to turn with little friction and by reason of its circular cross section, permits or causes all solid particles of grit or metal to fall away from the work, thus preventing the same from becoming scarred or scored thereby.

In practice, I provide several of the workrcst supports 45 with different heights of stool or upright supporting member, to the end that the axis of the object ground or operated upon by the

wheels

8 and 28 may be always somewhat below the common plane of the axes of said wheels, or of the axis of wheel 8 and center of wheel 28. The pur-" pose of thus maintaining the axis of the work below the plane of the centers of the wheels at the point of grinding, is to keep such work in a throat which decreases slightly in width upwardly from the points of contact with the wheels. By this arrangement the Work has three points of contact,-the lower or supporting contact c, the governing and feeding wheel contact a. and the grinding wheel contact 6. (See Fig. 2). The two points of contact 0 and 6 will. if the work, the supporting bar and the grinding wheel each be truly cylindrical and parallel. be a mere contact line. The contact d. will likewise be a straight line contact if the governing and feeding wheel 28 be truly cylindrical and its axis be parallel with the axes of the work, the work-rest, and the grinding wheel. If the axis of the govering and feeding wheel 28 be set oblique to the horizontal plane of the axes of the work and grinding wheel 8, the surface of the governing and feeding wheel will speedily wear slightly concave, the degree of concavity varying with the obliquity of the axis of the arbor or spindle which carries the governing and feeding wheel, but being apart to permit slight and almost imperceptible under any usual or desirable degree of obliquity of the wheel axis. \Vhen the wheel 28 becomes thus concave the bearing will still be along a straight line.

The office of the governing and feeding wheel as its designation would suggest, is to effect and to overn or control the rotation of the work, to support it properly in contact with the periphery of the grinding wheel, and to effect the axial traverse or feeding of the work, the wheel 28 acting upltlin the well-known principle of a skew ro The

wheels

8 and 28 are rotated in the same direction, that is to say, both rotate clockwise or both anti-clockwise, according as the machine is viewed from one or the other side, the larger or grinding wheel moving downward and the smaller or governing and feeding wheel moving upward where they contact with the work. Suitable provision is made whereby the rotation of the governing and feeding wheel is made relatively slow and that of the grinding wheel is made relatively fast. In practice, the speeds and the ratio of speed may vary within reasonable limits, depending somewhat upon the nature of the object ground and the amount of material which it is desired to remove in a given time or with a given traverse of the work. I have found for general use with iron and untempered steel, a speed of about 1000 revolutions per minute for the grinding wheel and 38-60 revolutions for the governing and feeding wheel gives satisfactory results, with an assumed diameter of twenty inches for the grinding wheel and ten inches for the governing and feeding wheel. In the drawings the wheels are shown of relative diameters of two to one, the grinding wheel being the larger, but neither this nor any other specific relation is essential to the successful operation of the machine. I therefore contemplate varying the same at will or as found expedient in grinding different metals, alloys, or other substances and under varying conditions.

Feeding adjiwvnwnt of governing and feeding wheel-4t is to be noted that under the arrangement shown in the drawings and with the grinding and the governing wheel axes when both are horizontal, lying in the same horizontal plane, the tipping or rocking of the governing wheel is about its central point, that is to say, about a point not only central with reference to the circumference or periphery of the wheel but 1 ing midway between the breasts or side aces of the wheel, when the wheel is a short section of a cylinder, as illustrated. In other words, the axis of tipping or rocking of the yoke 35 is coincident with a. line radial to the axis of the grinding wheel 8 and lying in a vertical plane which bisects the workin face or peripher of said wheel, and whic 1 when the axis 0 the governing and feeding wheel 28 is parallel with that of grinding wheel 8, similarly bisects the peripheral working face of said wheel 28.

Under this arrangement, which is preferred though not essential to successful operation of the machine. a more symmetrical construction, better balancing of parts, and minimum variation in extent of the line of contact between the governing and feeding wheel and the work, are secured. An important advantage of this location of oscillation or tipping of the yoke 35 and spindle or arbor 31, is that it involves no change whatever in the adjustment of the workrest or its support, that is to say, in the height thereof and consequent location of the work axis. The best attainable position or elevation of the work axis will under the arrangement just described, be the same whether the axis of spindle or arbor 31 be parallel with or more or less oblique to the axis of wheel 8. The ti ping of wheel 28 and its spindle or arbor about such centrally located point involves merely a partial rotation of said wheel 28 face-wise or breastwise, without any bodily translation or shifting of the wheel, whereas movement about an axis otherwise located involves such bodily shifting of the wheel and consequent change of relation of the wheel to the work and its support.

Under this arrangement a horizontal straight line will .pass through the axis of the annular plate 36 of the yoke 35, through the center of wheel 28, and through the center of wheel 8, and relatively slight tipping or tilting of said yoke will give suiticient obliquity to the axis of the governing and feeling wheel relatively to those of th work, work-rest and grinding wheel, to insure the axial feed or spiral advance of the work incident to the use of the skewed roll. Such adjustment can be made without in any manner disturbing the relation of the hearing or contacting point of the governing or feeding wheel with the work, or without necessitating a raising or lowering of the work-rest. A location of the pivotal axis of the yoke 35 a short distance to one or the other side of the medial plane of the wheel 8, while deemed undesirable, would nevertheless be within the limits of my invention, but the axis of oscillation should. to insure good results, be kept within the thickness of the wheel or not be carried beyond the side faces thereof. The more nearly the symmetrical arrangement is maintained, the more satisfactory is the operation of the machine, and the greater the facility and accuracy of adjustment, for reasons above pointed out.

Experimentation and practical tests have demonstrated material advantage in adjusting the governing and feedin wheel rather than the grinding wheel. In act, it is found that in order to get rapid and ellicient grinding, the grinding wheel must have a high sur face speed, whereas the work should be turned at a relatively slow speed, suflicient only to present the different faces of the work successively, gradual] and uniformly to the inding wheel. Since rotation of the work is effected and governed b the governing and feeding wheel, the sur ace speed of the latter must necessarily be relatively slow, and is in fact so slow as to produce no a preciable grinding effect, if indeed, there any slip or relative surface movement between the work and the governing and feeding wheel. Said governing and feeding wheel hence, by reason of its upward movement in contact with the surface of the work, rotates the latter about the work axis, and by reason of the skewed or oblique relation of the axis of the governin and feeding wheel relatively to thato the work, causes the work to advance axially with a spiral or screw-like motion across the face of the grinding wheel, thus resenting the entire surface of the work throughout the length thereof, progressively to the grinding face. The axial and the rotary move- Inents ofthe work are thus effected at a very uniform speed or rate, causing the grinding effect to be likewise uniform and insuring the equal grinding of every portion of the surface.

So far as I am aware no one has ever heretofore arranged an abrading or grinding wheel and a governing and feeding wheel in peripheral opposition, with their centers in common plane but with the axis of the governing and feeding wheel oblique to such plane, and driven said wheels both in the same direction, the grinding wheel at a relatively high speed and the governing and feeding wheel at a relatively low speed. This special combination and arran ement of grinding and governing and ceding wheels gives very satisfactory results, simplifies the construction, adjustment, and operation of the machine, and enables me to attain a recision of form and dimensions unattainab e by any prior grinding machine or structure of which I have knowledge. bCylinders, however short, may be ground y it.

Briefly restated, in a machine constructed as above described, the work-rest serves solely to support and guide the blank or object ground; the governing and feeding wheel serves to impart rotary motion to the blank or work at any desired surface speed or number of turns per minute, to hold the work up to or against the periphery of the grinding wheel and gage the space between the two wheels, and if the axis of the governing wheel be set oblique to that of the grinding wheel, said governing wheel also serves to impart to the work a longitudinal or axial Adjustment to accommodate work of different diametere.To enable proper adjustment to be made to suit or accommodate work of different diameters, I not only rovide separate work-rest supports or stoo s of different hei hts, but rovlsion is also made for setting t e governing and feeding wheel 28 closer to or further from the grinding wheel 8, and for positionin the work-suports so as to brin the axis of the bar 48 1n vertical plane with that of the work itself. This I accomplish in the manner illustrated in Figs. 1, 2, 3, 6, 7 and 8, wherein it will be seen that the bed or table 3 of the main frame of the machine is rovided with longitudinal dove-tail or un ercut ribs or ways 50, parallel to each other, and servin to support and guide the slide 41 whic carries the yoke-support 40, yoke 35, arbor 31, and governing and feeding wheel 28 as above described. Screwed into the back or inside face of the boss 39 or of the upright face or wall of the support 40, are two parallel rods 51 which extend through and project beyond the outer end wall of said support 40, as best seen in Fig. 6. Each of these rods 51 is shown encircled b a strong spiral spring 52, preferably woun to tapering or conical form, and havin their forward ends arranged to bear against the insidefaceofthe u ri ht inner end wall of the support 40, whi e t e outer and larger ends of the springs encircle bosses formed on a follower 53 sliding u on the rods 51 and carried by a heavy ro 54, the reduced and threaded end of which is screwed into the follower plate 53 and furnished on its protruding end with a binding or lock nut 55, as shown in Fig. 6.

The rod 54 is externally threaded throu h out the major portion of its length, an is encircled by a long cylindrical nut 56 flanged at one end and carrying at the opposite end a hand-wheel 57 keyed upon it, the tubular body of the nut being mounted to rotate in the tubular head of a post or standard 58, bolted or otherwise firmly secured to the outer end of the bed or table 3 of the machine. The nut 56 being prevented by the flange at one end and the hand-wheel 57 at the other, from moving endwise, will upon bein turned im art longitudinal motion to the t readed 1'0 54 and consequently to the follower 53, and through the latter to the su porting head 40 an slide 41, oke 35, arbor 31 and wheel 28, when sai rod is moved inward. As shown in Fi 6, the rods 51 are encircled by] tubular s eeves or coverings 59, outside or ack of the follower 53, and these sleeves are revented from esca ing from the rods 51 y nuts 60.

e initial com ression of the springs 52 may be varied as esired by turning the nuts 60, and the compression of the sprin will be such as to hold the governing and liding wheel 28 against the work with such pressure and firmness as to prevent pla or chattering and to afford the necessary riction to rotate the work.

The pitch of the screw thread on rod 54 is made relatively slow so that the slide 41 and the wheel 28 shall move but sli. htly for a given amount of rotation of the land-wheel 57, thus insuring delicacy of adjustment. In practice it is found extremel diilicult to get the last and very minute adzjlustment necessary to determine to the one-t ousandth, fivethousandth, or smaller fraction of an inch, the correct and precise position of the governing and feeding wheel. This it is found can often be attained more readily and accurately through a sli ht tapping of the slide or the support 40 than through turning the screw-rod to right or left, but the effect of the tapping will depend largely upon the weight of the hammer or other instrument, and the distance through and speed with which it is moved. To afford and keep always present and in position for use, a suitable tapping device, I pivot or hinge, preferably to the support 40, a weighted arm 61, arrangin the pivot and the weight in such relation t at by lifting the arm more or less and releasing it, the weight will fall by gravity and strike the rear or outer end of said support 40, and give the minute movement required to complete the inward adjustment. As the weight and the length of the arm carryin it remain constant, the extent of lifting 15 the only variable factor in the use of this device, and a little practice will enable the attendant to lift it to about the same distance and to get the precise amount of impact necessary. This simple expedient is found to be extremely useful in the practical adjustment of the machine, saving much time, and insuring accuracy of adjustment and consequently of the finished work.

Adjustment of work-rest and guide. The work-rest support 45 is carried upon and moves with the s ide 41, and is made capable of adjustment upon and relatively to said slide, to the end that the axis of the worksupporting rod or bar 48 may be brought in vertical plane with or directly below the axis of the work itself. This is accomplished by means of metal clamps 62, com rising flat metal bars each having one ownwardly turned end to bear upon the slide 41, and a tap-bolt 63 passing through a hole in the clamping plate and screwing into a threaded hole or seat in the upper face of said slide 41. The free ends of the clamping plates 62 overlie the bottom connecting bar 46 upon which the work-rest supports 45 are mounted, pressing and holding said bar firmly in contact with the top face of slide 41, and holdin it securely against movement when the b0 ts 63 are tightened. By slightly backing said bolts, the bar 46 is freed to permit its adjustment to bring the axis of rod or bar 48 directly below and arallel with that of the work, after which t e bolts 63 are tightened and the parts retained in proper position.

To uide the work in its passage between the wieels 8 and 28, and maintain it in proper relation to the cylindrical rod or bar 48, the

stools

45 and 45 are provided with angle plates 64 the horizontal members of which lie upon the tops of said stools, to which they are clamped in proper relation to the work b tap screws passing through slots 66 in said horizontal flanges and screwing into suitably tapped sockets or seats in the top faces of the

stools

45 and 45". The vertical flanges or members of the angle plates rest against opposite sides of the work, and being carefully arran ed in parallelism with the axes of the grin in wheel and of the work, they serve to gui e the same accurately both in passing to and in leaving the

wheels

8 and 28.

Device for preventing chatteriny.1t is found in practice that there is often a tendency of the workto chatter. owing to one or another cause which it is not always possible to locate. Such chattering tends to produce flats or flattened faces on the work, and for this and other reasons is to be avoided or prevented if possible. This desirable result I attain by means of a suitable friction device acting upon the governing and feeding wheel 28, which device is illustrated in Figs. 1, 2. 3, 6 and 7, the construction being best seen in the last-mentioned figure. It comprises two hinged or pivoted arms 67, each having an arcuate face preferably provided with a lining 68 of asbestos, or other substance capable of producing a considerable degree of friction and of withstanding the heat incident thereto. The lining may be omitted or may be of wood, metal, or alloy, but in practice asbestos is found to answer better than such metals or alloys. The arms 67 are hung or mounted upon a common pivot, which may conveniently be a tap-bolt 69 screwed into an arm 38 of the yoke 35. and are arranged raga- 24a to bear on opposite sides of a neck or collar formed upon the disk 30, as seen in Fig. 3. The requisite friction is produced by means of a spring 71 encircling a draw-bolt 72, which passes through the two arms 67 and throu h the springr 71, and is rovided with an a justin nut 3 and a 10c nut 74 to hold the nut 3 in its adjusted position. By turning down said nut 73 more or less, the compression of s ring 71 may be increased to the requisite degree, and said spring acting downward upon the u per arm 67, and upward on the lower arm 6 by reason of the upward pressure of the sprin beneath nut 73, will maintain a constant an uniform friction upon the neck or collar 70 and completel obviate an chattering of the wheel 28. This friction (levies I also find of very marked importance in securing a high degree of precision in the finished work.

As above indicated, motion is imparted to the grinding wheel 8 through a belt pulley 17 secured u on the shaft 7. Said pulley 1S driven by a elt 75 from a countershaft or prime motor provided with a belt wheel of such size relative to that of pulley 17 as to give the requisite or appropriate speed to wheel8.

Feeding wheel drive-The governing and feeding wheel 28, for reasons that will presently be explained, has a special drive including universal connections between the pulley shaft 76 and the spindle or arbor 31, as illustrated in Figs. 1 and 3. As shown in these figures, the shaft or arbor 76 turns in bearings 77 carried by a bracket 7 8 bolted or otherwise made fast to the main frame of the machine. The shaft 76 is connected with spindle or arbor 31 through a common form of universal coupling or exible connection, here shown as an intermediate short shaft 7 9, which may, if necessary, be composed of two telescoping lparts incapable of independent rotation, sai shaft being provided at its opposite ends with yokes connected res ectively with corresponding yokes secure to the spindle or arbor 31 and shaft 79, after the manner of the well-known Hooke or gimbal joint. Any equivalent universal coupling or flexible driving haft may be employed. As the inclination of the axis of arbor or spindle 31 is not great at any time, it is usually suflicient to allow slight play of the coupling pins of the gimbals in the yokes, as indicated in said Figs. 1 and 3.

By the use of this intermediate flexible connection or universal drive, wheel 28 may be adjusted toward and from wheel 8 and its axis of rotation be set parallel or oblique to the horizon at will, without disturbing at all the driving relation between said spindle or arbor and the shaft 76, which maintains a fixed position at all times.

Mounted upon shaft 76 are two belt pulleys 80, 81, the first of which normally pulley 80 is locked to shaft 76 for driving or impartin motion to the same, through a locking device of the character illustrated in F i 4. This it will be/seen, consists of a cylin rical roller 83 located in an eccentric cavity 84 in the hub of pulley 80, which cavity communicates with the eye of said pulley. The roller 83 is of slightly smaller diameter than the greatest depth of cavity 84, that is to say, its eatest measurement 0 a line radial to t c axis of shaft 76. r en the roller is in this deepest portion of the cavity, its surface will be out of contact either with shaft 76 or with pulley 80, and hence cannot couple or connect the two so as to impart motion through one to the other. When, however, said roller passes into a narrower portion of the cavity 84, still maintaining parallelism of its axis with that of shaft 76, it will wedge or bind between said shaft and the wall of said cavity, and firmly lock the pulley and the shaft together so that motion imparted to the pulley .will be transmitted to shaft 76 and through the intermediate connections to the wheel 28. To prevent this locking action taking place under both forward and backward rotation,a pin 85 is arranged lengthwise of the cavity 84 so as to arrest or to support the roller 83 when in that portion of the cavity having the greatest de th, or in other words, when in sition w ere it cannot exert its locking e ect. The use of the pin is resorted to as a matter of convenience in manufacture, since it permits the cavity 84 to be cut by a rotary milling tool in a very simple and expeditlous way. Any equivalent device for locking in one direction and releasing in the other, may be em loyed.

s above stated, the rotation of the wheel 28 is quite slow as compared with that of wheel 8, a difference in surface speed of course resulting from the smaller diameter of wheel 28 as compared with wheel 8. This difference, however, is multiplied many times by employing belt wheels of suitable relative diameters for driving the belt 82.

It is expedient at times to impart a much higher speed to wheel 28,.and this necessitates increasing the speed of rotation of shaft 76. It is desirable that this increased speed be made possible without unshipping the driving belt 82 or otherwise disturbing the adjustment and arrangement of parts of the machine. It is with this purpose in view that the pulley 81 is keyed or otherwise made fast to shaft 76. A belt 86 is arranged to run parallel with the base of the machine and is driven from pulley 7 to pulley 81, the pulley 7' bein formed as a continuation of the shaft 7. hen 1t is desired to speed up the wheel 28 for the purpose of drexing and truing its surface or for other reasons, belt 86 is placed upon pulley 81 and pulle 7" and turns shaft 76 at an increased spec This causes said shaft to run faster than but in the same direction as pulley 80, thereby carrying the locking roller 83 into the deepest portion of seat or cavity 84 and thus disconnecting the pulley from said shaft. The pulley will hence continue to turn at its normal rate, but the shaft 76 turning in the same direction though at a higher speed, will maintain roller 83 in its non-locking position until belt 86 is removed from pulleys 7 and 81, whereupon the shaft 76 being momentarily undriven, will be overtaken or overspeeded by the pulley, causing the roller to be carried into the narrower or shallower portion of the cavit '84, and to lock together the pulley an shaft.

Wheel dressing and timing deoice.1n a machine of this character it is im ortant to be able at any time to dress an true the working faces of the

wheels

8 and 28, which are ordmarily made of abrading material of like quality and texture or fineness, though I do not restrict myself to making both wheels of like material, either as to character or texture. I have illustrated in Fi s. 15 and 16 a simple and convenient means or effecting the dressing or truing of the wheels when required, and this without necessarily removing any part of the machine except the Work-sustaining rod or bar 48.

As indicated in Fig. 14, the outer end of each of the

stools

45 and 45 is provided with a tapped or threaded hole 87 to receive a tap-bolt 88 by which to attach to each of said stools a guiding block 89 having a slight overhanging ledge or shoulder 90 to rest upon the upper face of the stool. so that the block shall be held rigidly against any rocking or tipping when t e tap-bolt is turned tightly home. Each guide block 89 is formed with a rectangular opening 91 to receive and guide a bar 92, which carries the diamond-holder 93 equipped with a diamond or like dressing point 94, at each end. Cap plates 95 retain the bar 92 in place. The holder 93 is seated in'an opening extending from front to rear face of the bar 92, and is held therein by a set-screw 96. One end of the bar 92 is slotted or forked to receive a hand-Hover 97, the lower end of which is extended into a slot in the bottom plate 46 of the work-rest support 45, and pivoted upon a bolt or screw 98. (See Fig. 16.) Another screw or bolt 99 passing through the arms of the forked end of bar 92 and through a slot 100 in lever 97, affords connection between the bar 92 and lever 97 through which longitudinal recip- 1,4as,14a

rocation may be imparted to said bar 92 upon oscillating lever 97 about its pivot or fulcrum 98.

When it is desired to dress or true the

wheels

8 and 28, the wheel 28 is receded, guide blocks 89 are secured in ition upon the

stools

45 and 45" with \t 0 bar 92 in place and e uipped with the diamond-holder 93 and iamonds or points 94, and the stools are so adjusted as to cause the bar 92 to stand midway between the opposin faces of the wheels and to bring the diamon s 94 into cutting relation to the res ctive wheels. The

wheels

8 and 28 are then riven, the former at its normal speed and the latter at its abnormaher trulng speed, in the manner before explained. By traversing the diamonds crosswise of the faces of the wheels, while the latter are thus rotating, their surfaces are speedily dressed true and smooth. and made ready for precision grindll'ater circulation and deli'vcry.-To prevent undue heatin of the objects ground and of the grinding and the governing wheels, provision is made for supplying water thereto. To this end a nozzle 101 is arranged directly over the work support and work, as well shown in Fig. 2 and by dotted lines in Fig. 3. A regulating valve 102 is provided, by which the flow of water may be controlled or cut off at will, and a constant flow of the water so long as needed is caused by means of a pum 103 of any suitable character, shown in Figs. 1 and 3 as a. small rotar pump located near the floor, and secure to the base of the machine below the shaft or arbor 7 of the grinding wheel 8. A belt 104 passing about a pulley 105 on the shaft 7 and about a smaller pulle 106 on the pump shaft, serves to turn the utter at the requisite speed to cause water to be pumped from a tank 107 and delivered through the pipe 108 to the nozzle 101. The water flowing from the nozzle keeps

wheels

8 and 28 and the work between them, wet and cool and flows therefrom into the well 4, whence it drains by an outlet 109 and pipe 110 back to the tank 107. In this way the water is caused tocirculate from the tank through the pump 103, pipe 108, nozzle 101, well 4, and pipe 110 back to the tank, continuously so long as the shaft 7 is driven.

As more or less grit wears from the

wheels

8 and 28, and as articles of metal are removed from the odies ground, these are washed bv the water into and through the well 4 and thence into the tank 107. To

revent these matters from being carried y the water back to the pump and being thereby delivered upon the work and the

wheels

8 and 28, the tank; is divided into two sections b a cross partition 111. That section which receives the water forms a settling tank flows over the partition into the second compartment from which it is drawn by the pump, thereby leaving all of the waste mattor removed by the wheels in the settling portion of the tank.

110015 or cover or the wheels-To prevent injury to those aving occasion to use the machine and also to ard against water being thrown off into t 10 surroundin space by the

wheels

8 and 28, a hood 112 is hinged to one end of the machine frame, in position to be swung up over or outward and away from wheel 8. Its free ed may be arranged to rest upon an suitabe support of the machine frame. e wheel 28 may be covered by a similar hood, hinged to or carried by the yoke and extending toward the hood of the grinding wheel, but no claim is made to this common expedient.

As the journals for the several shafts turn in quite close fitting bearings, it is advisable to provide said bearings with oil cups of the sight feed type, permitting the attendant to note any failure of lubricant delivery or exhaustion of supply.

Operation-The machine being constructed as above described, the blanks or unfinished bodies to be ground are intro duced between the wheels from one side of the machine, guided in their entrance by the angle plates 64 and work-sustaining rod or rest 48. Owing to the obliquity of the axis of spindle or arbor 31 of the verning and feeding wheel 28, the work wlll be both r0- tated and axially fed oradvanced as wheel 28 moves upward and wheel 8 moves downward in contact with the opposite side of such work. The blanks may, if desired, be introduced by hand and moved forward sufiiciently far to cause the leading end to be engaged by the

wheels

8 and 28, or they may be caused to feed by gravity down a chute, guide or tube, one after another, and to be presented to and between the grinding and feeding wheels.

Whenever it is desired merely to grind short bodies without advancing them axially, the may be placed by hand between the grin ing and feeding wheels, the latter being properly adjusted but in such case having its axis parallel or in the same horizontal plane with, that of the grinding wheel 8. If for any reason it be desired to feed from the opposite side, the feeding wheel 28 may have its axis canted in a direction reverse to that normally given it, or contemplated in the foregoing description.

To enable the operator to determine accurately the angular relation 01' degree of obliquity of the axis of the governing and feeding wheel to that of the grinding wheel, the top of the circular face of supporting head 40 may be graduated, and a mark or and when it is full the water line may be made on the matching curved face of the annular plate 36 of the yoke 35, so that the ngmber of degrees of deflection ma be accurately and easlly read.

he foregoing describes that embodiment of the invention which experience has thus far indicated as best, and one which gives excellent results in use, but it is to be understood that variations, modifications, and substitutions may be made within the skill and the knowledge of designers and mechanics, without departing'from the limits of my invention, and that such changes are contemplated and comprehended within my invention in so far s they shall embody the rinciples and mode of o oration above set orth or shall fall within the range of known uivalents.

The drawin illustrate and this specification is pre icated u on, a construction in which the inding w eel and the governing and feeding wheel are each in the form of a short section of a cylinder, and in which said wheels, when their axes of rotation are parallel, lie in common horizontal plane, the wheels bein of like thickness and their breasts or side aces in common plane until the axis of the governin and feedin wheel is timed to secure the show roll f in effect. bviously, while this is the logica and preferred construction and arrangement, the principle or mode of operation, and the function or result, would not be at all changed if the axis of the grinding wheel were relatively higher or lower than that of the governing and feeding wheel, or if instead of being in true vertical plane the grinding wheel were in a plane oblique to the vertical, provided the relation of the several parts one to another remain as shown and described. In other words it is not essential that the centers of

wheels

8 and 28 both fall in a horizontal line or plane radial to the center of wheel 8, but said line may be thrown upward or downward from the horizontal plane to any extent desired, assuming that a corresponding movement or re-positioning of the governing wheel workrest support, and their adjusting and holding devices be made, so that except as to bodily shifting of said parts in a circular path around the axis of wheel 8 said parts shall continue to hear an unch relation to each other and to the whee 8. It is hence to be understood that the terms horizontal and vertical, used in the foregoing description, are predicated upon a specific embodiment of the invention, and the relative positions of parts illustrated in the drawings, and said terms are not to be construed as limitations or as in any sense restricting said invention to the placing of the wheel centers in a common horizontal plane.

Manifestly, the friction device for preventing chattering of the governing and feeding wheel may consist 0 a single arm held and pressed against the collar or hub by spring or weight, and the device for tap ing the governing wheel support in ma ing delicate adjustments may be a spring-supported weight or hammer arranged in any convenient way to permit retraction to a definite extent, and consequent iven throw and definite impact when re- Feased. Variations of the other details of the machine may similarly be embodied in more or less variant forms, common to like parts in analogous machines; thus the bearings of the grinding wheel 8 may be carried by a bed or slide adjustable to move said grinding wheel toward or from the governmg wheel, as has been done in analogous machines such as those for sizing metal rods and shafts. In other words, it is sufficient and generally preferable, to adjust but one of the wheels toward and from the other, and mere reversal or duplication of such means of adjustment would in no manner depart from the spirit of my invention.

The term governing and feeding wheel is used here to define a wheel which imparts rotary motion to a blank or object, and regulates or controls the surface speed thereof. Such wheel is variously designated in the art as a overning wheel, propeller wheel, regu ating w eel, feeding wheel, and the like.

The term yoke is here used to indicate a support which carries and affords a bearing for the journals of the arbor or spmdle 31, and is em loyed as a generic term for a structure ful lling this definition whether made in the precise form and built up of se arate pieces, as here illustrated, and w ether having two arms and bearings, one at each side of the governin wheel, or with a single bearing at one si e thereof. The term bearings as used in the claims with reference to the yoke and the arbor or spindle supported thereby, is intended to comprehend or include both the two bearings at or near opposite ends of the spindle or arbor, and the single bearing construction at or near one end thereof, and the claims are to be read with this understanding.

So, too, while I have shown and deem it advantageous to provide, a three-point bearing in which the throat or passageway for the work formed b the grinding wheel,

overnin wheel and work-rest, narrows at t e side urthest from the work-rest, this is not essential to effective operation of the machine, and such throat may be higher or lower as desired with reference to a plane passing through and parallel with the axis of the rinding wheel and through the center of tie governing wheel.

N 0 claim is herein made to the water supply and circulating apparatus, or to the deyoke rotatable a vices for dressing or truing the grinding tinuation of appllcation Serial No. 533,067,

heretofore allowed, and contains certain claims taken therefrom, but embraces an-l claims also certain features and details nut disclosed in the earlier application.

Having thus described my invention what claim is 1. A grinding machine comprising a grinding wheel carried in bearings; a work support arranged across and near the periphery of said wheel; a second wheel peripherally opposed to the periphery of the grinding wheel, located on the oppos'te side of the work su port and journalcd in a out an axis passing through the centers of said wheels, radial to the axis of the grinding wheel, and lying in a plane bisectin the peripheral working face of the tin ing wheel; and means for rotating said wheels at suitable speeds.

2. A grinding machine comprising a grinding wheel carried in bearings; a work-support arranged across and near the periphery of said wheel; a second wheel peripherially opposed to the periphery of the grinding wheel, located on the opposite side of the work-support and journaled in a yoke rotatable about an axis radial to the axis of the grindin wheel; and means for rotating said whee s at suitable speed and in the same direction about their respec tive axes.

3. A grinding machine comprising a main supporting frame; a shaft rotatably mounted in bearings thereon; a grinding wheel carried by said shaft; a slide movable upon the supporting structure toward and from the grinding wheel; a support carried by said slide; a yoke pivot-ally mounted upon said support and provided with bearings; a spindle mounted in said bearings and carrying a governing and feeding wheel in peripheral opposition to the periphery of the grinding wheel; a rest or support for the work between the grinding and governing wheels; and means for rotating said wheels, substantially as set forth.

4. In a grinding machine, the combination of a supporting structure; a shaft or arbor journa ed in bearings thereon; a grinding wheel carried by said shaft; a slide carried u on said supporting structure and mova le toward and from the grinding wheel; a support carried by said slide; a yoke pivotally mounted upon said support and capable of oscillation about an axis radial to that of the grinding wheel and lying in a plane which bisects the periphera working face of said Wheel; a spindle journaled to rotate in bearings carried by the arms of said yoke; a governing and feeding wheel carried by said spindle and having its eripheral face opposed to the peripheral ace of the grinding wheel; a work rest or support between the grinding and governing wheels; and means for rotating said wheels in like direction about their axes and at suitable speeds.

5. A grinding machine comprising a main frame; a grinding wheel carrie by a shaft rotatable in hearings on said frame; a governing and feeding wheel having its periphery opposed to the periphery o the grindin wheel; a spindle 0r arbor carrysai governing and feeding wheel; a yo e in which the spindle is journaled; a

support carried by the main frame and upon which said yoke is pivotally mounted; a work-rest intermediate the peripheries of said grinding and governing wheels; a support for said work-rest; means for moving one of said wheels toward and from the other; and means for im tion to said wheels in t e same direction about their axes and at suitable relative speeds.

6. A grinding machine comprising a supporting structure provided with bearings; a shaft or arbor journaled in said bearings; a inding wheel carried by said shaft or at r; a governing and feeding wheel; a spindle for said wheel]; a yoke in which said spindle is journaled, said yoke being capable of oscillation in a plane parallel with that of the axis of the grinding wheel, whereby the axis of the governing and feeding wheel may at will be set parallel with or oblique to that of the grinding wheel; means for rotating'said wheels at desired speeds and in the same direction; and a work sup ort located between the wheels and exten ing transversely of their peripheral working faces. a

7. A grinding machine comprising a supportingl structure provided with bearings; a s aft or arbor journaled in said bearings; a grinding wheel carried by said shaft or arbor; a governing and feeding wheel; a spindle for said governing and feeding wheel, having its axis at a slight inclination to that of the grindin wheel shaft or arbor but in a plane paral el with that of said shaft or arbor, said wheels being peripherally opposed or in tandem relation; means for rotating said wheels as desired speeds and in the same direction' about their respective axes; and a work-support located between the wheels and extending transversely of their peripheral working faces, one of said wheels belng adjustable toward and from the other.

8. A grinding machine comprising a supporting structure provided with bearings; a shaft or arbor journaled in said bearings; a grinding wheel carried by said shaft or arbor; a governing and feeding arting rotary mo-\ posing wheel peripherally o posed or in tandem relation to the grin ing wheel; a spindle for said wheel; hearings in which said spindle is 'journaled; means for rotating said wheels at desired s eds and in the same direction about their respective axes; a work-su port located between the wheels and exten ing transversely of their peripheral working faces; and means for ad'usting one of said wheels toward and tom the other.

9. In a grinding machine, the combination of a main sup orting frame; a shaft or arbor journaled 1n bearings thereon; a grinding wheel carried by said shaft or arbor and having a peripheral grinding face; a slide mounted upon the main frame and movable toward and from the grinding wheel; a work-governing and feeding wheel journaled in bearings carriedby said slide and having its eripheral face in oprelation to t e periphery' of the "grindlng wheel; and a work support intermediate said wheels, mounted upon and movable with said slide, and also adjustable upon and relatively to said slide; whereby the work support may be placed with its axis parallel with that of the grinding wheel and midway between the opposed working faces of the two wheels under all adjustments of the slide.

10. In a grinding machine the combination of a main exporting frame; a shaft or arbor journal in bearings thereon; a grinding wheel carried by said shaft or arbor and having a peripheral rinding face; a carrier supported by the main frame and movable toward and from the grinding wheel; a work-governing and feeding wheel 'ourn led in hearings on said carrier and aving its peripheral face opposed to that of the grin ing wheel; and a work-support intermediate said wheels, mounted upon and movable with said carrier.

11. A grinding machine comprising a main frame; a shaft journaled in bearings in said frame; a grinding wheel carried by said shaft; a slide movable toward and from the inding wheel; a governingand feedin w eel carried by said slide; means for a vancing and receding the slide and overning wheel; and a device carried by t e slide and serving to give a light but regulated impact thereto, to effect a slight movement or adjustment thereof.

12. A grinding machine comprisin a main supporting frame; a grindlng wheel mounted to rotate thereon; a slide movable toward and from the grinding wheel; a work support carried by said slide; a governin and feeding wheel also carried by the 8 de; and an undpact device carried by the slide and adapte to impart a light but controllable impact to the slide to effect minute adjustment thereof.

13. A indin machine compri a main fra i e; a grinding wheel carr i g in bearin thereon; a governing and feeding wheel iaving its perl hery (:pposedto that of the grinding whee a sli e movable toward and from the grindin wheel; a tilting support carried by said s ids and having hearings in which the governing and feeding wheel is carried; and means for rotating said wheels in the same direction and at relatively different speeds.

14. A grinding machine comprising a main frame; a horizontal shaft supported in bearings thereon; a grinding wheel carried by said shaft; a governing and feeding wheel arran d with its periphery in opposition to t at of the grindlng wheel; a spindle for said governing and feeding wheel; a tilting support having hearings in which said s indle is supported; an intermediate wor support; and means for securing the tilting support at any desired degree of obliquity to the horizon; whereby the governing and feeding wheel is caused to impart rotation to an object lying upon the work support, and to advance the same axially at a s eed de ndent upon the relative obll uity o the axis of the governin and feeding wheel to that of the grinding wheel, work support, and work.

15. In a grinding machine, the combination of a su porting frame; a grinding wheel carried y a shaft journaled in bearings thereon; a ioverning and feedin wheel arranged wit its periphery opposed to that of the rinding wheel; a spindle or arbor for said governing and feeding wheel; a tilting support hav'n bearings in which said spindle is journafed; and a work support between said Wheels; said tilting spindle support being adjustable at will to position the axis of the governing and fee ing wheel parallel with that of the grinding wheel, the work and the work support, or oblique thereto, as desired.

16. In a grinding machine, the combination with a grinding wheel having a shaft journaled in bearings; a governing and feeding wheel peripherally opposed to the periphery of the grinding wheel, and having a spindle mounted 1n bearing:a in a tilting support; a work support tween said wheels; and means for rotating said wheels in the same direction and at proper speeds.

17. A grindin machine comprising a main frame; a s aft journaled in bearm thereon; a grinding wheel carried by said shaft; a spindle journaled in bearings in a plane parallel to that of the grinding wheel axis; a governing and feeding whee carried by the spindle and am d with its periphery in opposition to that-of the grinding wheel; a tilting support for said spindle movable about an axis lying between the side Walls or faces of the governing and feeding wheel; and means for securing the tilting frame at any desired angular adjustment.

18. In a inding1 machine of the character descri d, an in combination with a (grind ng wheel and with a governing an feedmg wheel peripherally opposed one to the other; an intermediate work support comprising a pair of stools connected and spaced apart by a bar, said stools being recessed on their upper faces to receive a work rest; a rod or bar seated at its ends in the recesses of the stools and constituting a work rest and means for clamping the ends of the bar in said s.

19. In a finding machine of the character descri d, comprising a grindin wheel and a governin and feeding wheel arran d in eriphera opposition; a slide provi ed wit hearings in which the verning and feeding wheel is journal a work support mounted upon and movable with the slide and carrying a work rest extendinghbetween and across the working faces of t e opposed wheels; and means for releasably securing the work support to the slide; whereby the work rest when adjusted is maintained in proper relation to the governing and feeding wheel durin recession of the slide, and may be at once grought back to proper relation to the grinding wheel when the slide is returned to working position with the work lying upon said rest 20. In a grindingmachine comprising a main frame and a slide movable thereon; a grinding wheel journaled in the main frame; a governing wheel journaled in bearings carried by the slide; and a work rest releasably secured to and adjustable upon the slide, and movable with the slide toward and from the grinding wheel.

21. In combination with the main supporting frame of a grinding machine, a grinding wheel journaled therein; a slide movable toward and from the indin wheel; a. raised support carried said slide' a governing and feeding whee journaled in a yoke carried by said support; rods rigidly secured to and projecting from said sup ort; coiled springs encircling said rods an bearing at one end against the support; a cross head sliding upon said to s and bearing against the slprm retaining devices app ied to sai re s and serving to retain and to adjust the cross head upon said rods; a screw-threaded rod rigidly attached to the cross head and held against rotation; a post mounted upon the main frame and having swiveled in it a nut screwed upon the threaded rod, and provided with turning means' whereby the governing and feeding whee may be adjusted toward and from the grinding wheel and yieldingly held in contact with the work between said wheels.

22. In a. grinding machine of the character described, a grindin wheel; an opposed governing and fee ing wheel; and a friction device acting u n, and serving to steady the rotation o the governing and feeding wheel, and to prevent chattering in action.

23. In combination with a grindin wheel and an opposed governing and fee ing wheel: a yielding friction device actin upon the governing wheel or its arbor, an serving to prevent vibration or chattering thereof.

24. In a grinding machine, in combination with a grinding wheel and a governing and feeding wheel. a friction device comprising two pivoted jaws cla ing a collar of the governing wheel; a ho t passing from one to the other of said jaws; a spring encircling said rod and bearing at one end against the outer face of one of the jaws; and means for varying the compression of said spring.

25. A grinding machine comprising a sup rting frame; a grinding wheel having a s aft journaled in bearings thereon; a slide movable upon the frame toward and from the grinding wheel and provided with a raised support; a yoke pivotally mounted upon said support and capable of oscillation about an axis radial to the axis of rotation of the grinding wheel; a governing and feeding wheel having its spindle journaled in hearings in said yoke; a driving shaft; and a shaft intermediate the driving shaft and the spindle and connected with each by universal couplings; whereby motion may be imparted to the spindle and adjustment of the spindle toward and from the grinding wheel and about the pivot axis of the yoke is permitted.

26. In a grinding machine. the combination of a grinding wheel and a governing and feeding wheel peripherally opposed; a slide by which the governing and feeding wheel is carried; a work support comprising stools connected by a bar; clamps secured to the slide and bearing upon said bar, and serving to hold the stools in proper position between the two wheels; and a work rest carried by said stools.

27 In combination with the grindin and feeding wheels of a centerles grin er, a work support located between said wheels and comprising two separated stools having grooved upper faces; a cylindrical rod lying in said grooves and forming a work rest or hearing; and means for releasably securing said rod against rotation.

28. A centerless grinder comprising a grinding wheel and a feeding wheel peripherally opposed one to the otheran a work support intermediate the said wheels and rallel with the axis of the Bufi'inding whee said work support being ciently below the horizontal plane of the wheel centers to cause the work axis to be likewise below said centers; whereb work lying upon said support will be co ed in a space decreasin in width from the work support upwar and thus prevented from rising from said support.

29. In a centerless grinder, the combination of a supporting frame; a horizontal shaft journaled to rotate in said frame; a. grinding wheel carried by said shaft; a spindle having its axis in a vertical lane parallel to that of the grindin wheefaxis; bearlngs in which the journ s of said spindle are mounted; a governing and feeding wheel carried by said spindle and peripherally opposed to the periphery of the grind wheel; a work sfiggport intermediate s i d wheels and loca sufliciently below the horizontal plane of the wheel centers to cause the axis of work resting on said support to be below the plane of'contact of said work with the grinding and feedin wheels, and consequently below the plane 0 nearest approach of said wheels; and means for rotating said wheels in the same direction about their respective axes and at appropnate relative s 30. In a grin machine, the combination of a grinding wheel and a governing and feeding wheel mounted to rotate in peripheral opposition to each other' means for rotating said wheels in one and t e same direction about their respective axes; a work-rest extending between the proximate peripheral faces of said wheels transversel of said faces; and supports for opposite an s of said work-rest, located wholly outside of the side faces of said wheels and beyond the area.

31. A ro grinding machine comprising a supporting structure; a grin wheel journaled thereon; a carriage supported for movement toward and from the 'phe of said wheel; a governing or ating v v heel journaled on the carriage; and a workholder also mounted on the carriage to move with the governing or regulatin wheel and arranged to support the work tween the wheels.

32. A roll grinding machine comprising a supporting structure; a grin whe journaled thereon; a carriage supported for movement toward and from the riphe of sa1d wheel; a governing or regu sting viz heel carried by said carriage, and tilted from the plane of rotation of the grinding wheel for effecting a feeding of the work, said wheels being positively driven at different speeds and having their peripheries op to one another; and means for supporting the work between the wheels.

83. A roll grinding machine comprising a pair of angularly related wheels having their peripheries op osed to one another; a stat-iona round ro part extending between the perip eries of the wheels but out of contact therewith and means for adjustably holdin the rod part in position.

34. roll grinding machine comprising a supporting structure; a grinding wheel journa ed thereon; a carriage supported for movement toward and from the peri hery of the wheel; a governing or re gu ating wheel supported on the carriage in tilted relation to the grindin wheel; a workholder also mounted on t e carriage to move with the regulating wheel and to support the work between the co-acting peripheries of the Wheels; and means for yieldably advancing the carriage toward the grinding wheel.

35. A roller grinding machine comprising a grinding wheel; a governing or regulating wheel a slide member carr 1n the latter; a guiding su port traverse 1e y the slide member; an work-supportin means carried on the slide member in a vance of the regulating wheel, and adjustable thereon.

36. A roller grinding machine comprising a grinding wheel; a governing or regulating wheel' a slide member cart 11 the latter; a guiding support traverse la y the slide member; spaced posts or stools on the forward end of the slide member, one on each side of the wheels; a work-su porting member between the wheels; and c am in means carried by the posts or stools or olding the work-supporting member.

37. A grinding machine comprising a inding wheel; a shaft for said wheel and earings for said shaft; a governing or regulating wheel; a shaft for said wheel and bearings for said shaft; means for imparting rotation to the respective shafts and wheels in the same direction about their axes and at appropriate speeds; and a work-rest intermediate the opposed peripheries of said wheels, the governing wheel having its shaft so mounted as to permit its axis to be placed in oblique relation to the grinding wheel and to the bearing face of the work-rest, whereby 1,4aa,14a

the grinding overnin wheel is caused to rotate and ongitudmally feed the work, and

the work-rest is caused to maintain the work in proper relation to the grinding and govermng wheels.

38. A grinding machine comprising a gzinding wheel; a shaft for said wheel and arings for said shaft; a governin or regulating wheel; a shaft for said w eel and bearings for said shaft; means for impartmg rotation to the respective shafts and wheels in the same direction about their axes and at a propriate speeds; and a work-rest interme late the opposed peri heries of said wheels, the governing wheel shaft being mounted for tipping about an axis radial to the true center of the grinding Wheel.

39. A grinding machine comprising a grinding wheel; a shaft for said wheel and bearings for said shaft; a governing or regulating wheel; a shaft for said wheel and bearings for said shaft; means for imparting rotation to the respective shafts and wheels in the same direction about their axes and at appropriate speeds; and a work-rest intermediate the opposed peripheries of said wheels, the governing wheel shaft being mounted for tipping about an axis radial to the axis of the grinding wheel, and lying between the side faces of said grinding wheel.

40. A grinding machine comprising a grinding wheel; a shaft for said wheel and bearings for said shaft; a governing or regulating wheel; a shaft for said wheel and bearings for said shaft; means for imparting rotation to the respective shafts and wheels in the same direction about their axes and at appropriate speeds; and a work-rest intermediate the opposed peri heries of said wheels, the governing whee shaft being mounted for tipping about an axis radial to the axes of the two wheel shafts and 1 ing in a plane midway between the side aces of said wheels.

In testimony whereof I have name to this s ecification.

FRANCIS C. SANFORD.

signed my