US2004949A - Grinding apparatus - Google Patents

Description

lJune 1'48, 1935. B, Q :50M 2,004,949

GRINDING APPARATUS Filed July 25, 1928 2 Sheets-Sheet l JZ if "5 3.5 Ow E' a 6/ /AVENTOR A TTORNEY June 18, 1935. B. o. lsoM GRINDING APPARATUS Filed July 23, 1928 l 2 Sheets-Sheet 2 1N VENTO/e Y w., m m f M Y 0.7, W` M m nDY B Patented `lune 18, 1935 g UNITED srrxrizsI GRINDIGAPPARATUS l' Benjamin 0. Isom, Detroit, 'Mich., assigner to Hutto Engineering Company, IInc., Detroit,v `Mich., a corporation'vorf Michigan A g ymmiicamm July` 23. 192s, s eria'i No. 294,669

v14 claims.v (ci. soli-184.3)

This invention relates to devices for vfinishing cylinder bores orlike' surfaces and is ofthat type commonly known as vhones or cylinder grinders, the principal object being the provision of'a new v and novel device of this type which will permit more'accurate work'to be accomplished bythe same.

Another object is to provide a device of the type'described whei'ein theabrasive members may automatically adjust themselves to parallel relationship with respect to the surface being actedl upon.

Another object is to provide a device vof the typedescribed wherein the means for'controlling the diameter across the abrasive members is positive inaction. r` f ,Another object is to provide a device of the type described wherein the abrasive members `are mounted to pivot about a point perpendicular to their length. f

Another object is to provide a device of the type described inwhichthe abrasive members are permitted to have a pivotal action about a line'perpendicular to their length but which pivotal actionisl frictionally resisted.

Another object is to provide in combination with a device of the type described; means for preventing undesirable shiftingof the abrasive members during operation.

Another object is to provide anew and novel assembly of parts yfor a devicey of the typedescribed.

A further object is to provide a new andnovel adjusting head for a device of the type described.

The above being among the objects ofthe present invention, the same consists in certain features of construction and .combinations of parts to be hereinafter described with reference tothe accompanying drawings, andthen claimed, having the above and other objects in view. 1

In-the accompanying drawings which illustrate a suitable embodiment of the present invention and in which like lnumerals refer to like parts throughout the several different viewsj Fig. 1 is a sectional view taken through the axis of the grinder head of a device constructed in 'accordance with the present invention, the section being taken on a line correspondingto'theline.

' :the devices of this tvpenow-on `the marketf'fis l-v-lofFigZ.

Fig. 2 is a sectional view taken on the line 2- 2 0f Fig. 1. v.

Fig. 3 is a sectional view taken on the line 3,.- 3 of Fig, 1.l o Y Fig. 4 is a perspective view of one of the completely assembled abrasive members. Y

`one end of one or more of the abrasive elements expanding means therefor."

Fig. 5 is a partiallyv'broken and partiallysec'-v tional side view of an adjusting head for use in connection with thel grinder head shown in Fig. f1 taken as on theiine 5 5 of Fig. 6. f f

Fig. Gis a sectional View taken on the line 46 6 5 ofrii'g.` y Fig. 7 is a sectional view taken on the line 1-1 ofrigs. Y

. Fig. 8 is a sectional view taken on Vthe line `8--8 ofFig.5.o Fig.l 9 is a perspective view ofthe member which nonrotatably connects the .adjusting and driving head 'to the driving shaft. l `Devices of the type herein referred to are commonly employed for finish machining thecylinder bores of internal combustion engines during production thereof, and also for refinishing. suchbores after they have been worn in service. f Alf.v though these devicesv are commonly .known vas hones, such name is in Vrealityfmisleading; 'in view-y of the ,fact that they are primarilya grinding device as differentiated from ahoning device. r Such devices have come into relatively wide luse in the past few years. As far as I am aware no device of vthis type made its appearance in which 25 means are specifically provided to permit, the abrasivev elements to .shiftxtheir position -along their length relative to thefaxisof fthe device. That is, inthe conventional constructions when actuated tol increase or decrease their diameters, the' base of the abrasive elementis maintained in a constant parallel or approximately parallel relationship with vrespect to the axis of the grinding head. It often occurs that the materialat may be of softer composition than the other end thereof with the result that the soft end will wear much quicker than the other end, ,and kafter a short time in operation only one end-of the abra-y o sive element will be doing any substantial amount of grinding. In accordance with 4the present invention I provide means whereby each abrasive relement may rock in a planepassingthrough the axis: of the grinding head so that such elements 5 may adjust themselves for equal pressure against thesurface being ground over theirf'e'ntire length.

, Furthermore, as far as'I am aware, `in none of equal"contra ction o'fithe opposite endsf'of the 50 .abrasive'elements insured upon' operation of the 1 lin-"other words, no means are provided which-positively insures equal decrease in diameter of the grinding head over the entire length thereof. The presentinventlon PAT-ELN T OFF l approaches the outer 2. also provides means whereby this may be accomplished.

Referring y to Vthe accompanying drawings 2|! represents the body of the grinding head which is provided with an axially extending and axially.

concentricopening 2|. lThe exterior surface of the body 20 is provided with six equally/spaced axially parallel grooves 22, although the number of such grooves may be varied tosuitthe desires of the'particular designer or necessities ofthe particular object being worked upon as will readily be apparent. Extending radially inwardly from the bottom of each of the grooves-22 Vand disposedin parallel relationship lwith respect to the length thereof mentally shaped groove 23, the bottom Lof which Received within the bore 2| is a member 24 having integrally formed thereon two spaced similarly' facing cone surfaces 25 and 26. The body 'portion '2liV is provided with two spaced sets of radially extending openings 21 and 26, .each set there are grooves the bore 2| to the bottom of one of the grooves/22,

. the openings 21 and 28 being spaced axially" of the body portion 20S an amount commensurate with the axial spacing of the cone surfaces 25 and26; In each of the openings 21 and 23,'a pin 29 is'received,the inner lsurface of which is bevelled inv accordance with lthe angularity of the cone surfaces25` and 26 and whichbears against the correspondinggsurface of such cone surfaces. The outer ends ofthe pins 29fare slotted as at 30 in a direction parallel to the axis of the body por:-

vtion 20, the slots 30 in'operation being aligned with the grooves 23.

` ofthe grooves 22 against `,theouter edge of each plateA member 3| isan abrasive element shown best infperspective in Fig. 4. Each abrasive element preferably comprises an outer channel section member 33 which closely receives therein an inner channel section member 34 which in turn receives and in which is secured the abrasiveI strip 35. The outer vmember-.33 adjacent its center isprovided with two inwardly yextending spaced ymembers 36, each ofwhich is provided with an opening 31 at its inner endhparallel to the length thereof and each of which is divided midwayits length by a slot 38. Each member 33 is slidably received inr one of the grooves 22 with the members 36 straddling the corresponding `plate3l Vand with the bottom of the member 33 bearing against the end portions of the outer edge vof the corresponding .plateumember 3|. f i

" In order to prevent axial movement of achiabrasive velement relativeA Vthe pins 4|*being of substantiallythe same diameter as they width of the slot 40, and its projecting ends being slidably received therein.

, in the members 36 of each a relatively narrow .seg-Y walls of thel' bore` 2|. t.

comprising as many openings as' 22"andjextending radially fromto vthe body. 20, the b ody4 f- 1 20 isprovided with .la circumferential" groove 70A Where the members 33 are of diecast construction, which may be preferable in some cases, the

pins 4| may, in such case, be cast integrally with the members 33 for economy in production. The abrasive elements are maintained against vthe outer edge of their respective plate members 3|,

and the plate members 3| the bottom of the grooves 30in the pins 29Min the following manner: A cotter pin 42 isy inserted through one of the openings 31 vof each of the abrasive elements and an endless coil spring such as 43 `is positioned in the groove 40 over each of l the cotter pins 42, it passing through the slots 38 abrasive element and through the notch 44 provided in each of the plate'members 3| for this purpose. It will be apparent that the action of the spring 43 in tending vto contract draws the abrasive elements against the plates 3|, pins 29,2 andthe pins conicalsurfaces 25 or 29 against their*v respective 26 asthe casey may be. f

` Frornthe foregoing it will be apparent that each plate member 3| which is'freelyrreceived in 'its corresponding groove 23may slide in the grooves 30 of the corresponding pins 29 about the' axis of its circular center, and that the abrasiveelethe plates 3| against thev are maintained against i ments will move in accordance therewith. Thus, 4

either endofeach'abrasive element may shift inwardly or outwardlyy in order for the outer sur-y face thereof to align itself with the ,borel of Vthe object being operated upon, `regardless of the degree of wear of either end of the abrasive elements. This insures the entire surface of each abrasive lelement being. in contactV with the bore Yof the object being worked upon, with the result that faster and moreA accurate work maybe accomplished thereby. Furthermore, as the grooves3|l in the pins 29 are formedy to provide maximum bearing for the curved edges of the platemembers 3| received therein, and due to the .fact that l the members 3| must slide ratherthan rockin the grooves 30 in order 26 land 26. together is that when' the member is i shifted axially in the bore 2| to either: increase or decrease the eiectivediameter of the grinding head through the pins 29, a uniform reduction or f expansion over the length of the abrasive elements takes place. This is in `contradistinction to-those conventional typev'sof devices in which the conical f surfaces are urged towards proper relation with respect to each other by a spring'means-which sometimes allows a greaterfreduction of the diameter at one end of the device than at the other end thereof when the cones are backed off topermit withdrawal of the device from the core of thev object being kworked upon.

' In assembling the grinder head kI prefer to place the cotter pins in the opening 31 of each of the abrasive elements which is less advanced in the y direction' of rotation of' the'grinding head than the other openirg31. This isfor the reasonthat when Vthere is an'appreciable lateral play between the abrasive elements and their respective grooves 22, the pressure of the spring`43 will draw the less advanced edge of the abrasive strip 35 radially inwardly so that when the grinder head isinserted in the bore to be Worked upon and rotated, there will be no danger of the abrasive elements cookingv in their grooves and thus inadvertently pressing an edge of the abrasive strip 35 into the wall of the bore so as to vcause a tearing orv other unevenness of the same such as occasionally occurs in conventional constructions. This same arrangement also prevents4 chattering of the grinding head. The cotter pins 4.2 may, of course,

be shiftedfrom one of the openings 31 to the opposite opening in accordance with the rotation of the grinding head. Y t

The axialposition of the cone member 24 in the bore 2| Vis controlled in the following manner: The upper end of the lmember 24, as viewed in ydirection of Fig. 1 is provided with an .internally threadedr opening 44,'and threadedintothe opening 44 is a screw member '45. The body portion of the mem` ber 24 is providedl with an axially extendinggroove 46, anda screw member 41 (seevFig. 2)4 threaded' through the body member 20 at the bottom of the slot 40 projects radiallyy into the groove'y 46,'thereby preventing rotation of 'the member- 24 rbut a1- lo'wing axial movement thereof within the bore 2|. The bore 2| is enlarged asat 49 to provide a shoulder against which a washer 5|` seats.'

The screw 45 rotatably projects through the wash-` er 5| and is provided on the' upper side thereof with an enlarged head'52 which is separated from the washer 5| by a plurality of anti-friction balls 53e Thehead 52A which is maintained against axial movement in a mannerwhich will presently be described is provided with an faxially posif` tioned squareopening 54 in which a square shaft 55 is received, and the rotatable position of which is controlled, as will hereinafter be explained, to control the rotatable position of the screw 45 relative to the body y20 and consequently the axial position of themember .24 within the bore 2|. The anti-friction balls 53 vare provided between the head 52 vand washer 5| lin-order to reduce the excessive friction thaty often occurs atjthis point when the screw vr45 is rotated to draw. thecone member 24 upwardlyin the boreA 2| to increase the diameter over the abrasive elements while the grinding head is in a bore being operated upon.`

. In devices of thistype the'grinding head vis rotated and moved axially and such movements ordinarily occur simultaneously. The rotational and axial movement kof the grinding head in thisl case isimparted thereto through the hollow shaft 56 in the following manner' 'The upper. end of the body 20 as viewed in Fig. 1- is provided ywith a spherical Lseat 5'! against which restsl a ball 58 vformed on the lower yend ofthe shaft56. The lupper .end of the body portion!!! is slotted as at 59,

VVand received within the slot 59 on either side of the shaft 56 are the upwardly extending wingsrG-I `'of a washer member 62 which overliesthe upper end of the opening 49.A The ball 58 is .diametrically slotted as at 63 and the inner edges of the wings', 6| are received in such slots.

l K The wings 6| ,are thus received'in both the slot'r5'9`of the head 2 0 and the slot 63 of the ball 58,`thereby nlocking thel head 20 to the shaft 56 for equal rotation. Split bearing members 64 having spherical seats 65 are received in the upper end ofthe body 20 in contact with the ball 58 between the wings 6 I andare held in position on the head 20 by thecap member 66 to prevent axial movement of the shaft 56 relative to the body 20. `lThe cap member 6 6 is locked against relative movement by means of the lock nur; s1. y

Within the opening 49 and surrounding the against the upper edge of which the washer 62 is adaptedtobe clamped by the cap 66 which not only bears against the upper4 surface of the seat members 64 but also against the upper edges of the wings 6|. The spacer68 is of sucha'length that the -head 52 of the screw member 45 is clamped againstfa'xial movement between the washer 62 andwasher 5|, proper clearance for the balls 53 being taken into consideration. The head 52 ofthe screw 45 is therefore free to rotate but is4 positively held against axial movement relative'to the body 20. The result is that upon rotation of the screw 45 in either direction,- the cones 25 and 25 are given a positive axial rmovement within the bore 2|, and inasmuch as the cones 25 and 26 are integrally connected together the axial movement of each of them is positively assured. This is a marked advantage over anyfof the conventional constructions of which I am f aware due to the fact that in such conventional constructions the cone sur-faces when integrally ing upon spring means for movement, such fric tion may at times overcome the force of the spring andthereby cause imperfectaction of the,

device. In fact, this is a common occurrence in conventional constructions and is usually remedied by striking the bodyofthe grinding heady with a hammer or other object in order to break the pins loose from the cones. No explanation is necessary to point out the undesirability of such procedure. In the present construction, positive and equal axial movement of the cone surfaces 25 and 26 is assured.

- When devices of this type are employed inthe4 production of'automobile cylinders it is desirable for economys 4sake to be able to accurately adjust 4the diameter across the outer surfaces of the abrasive 'elements without stopping rotation of the grinding head. Furthermore, inasmuch as" it is necessary to reduce the diameter of the grind? ing head after grinding one bore and before insertion in another tore, u is desirabierto prvide means for easily and accurately bringing the effective outsi'de diameter of the grinding head toa pre-determined maximum without stoppingop' eration of the machine', `In the present invention means are provided for accomplishing this in the following manner as illustrated in Figs. 5 to 9 inclusive. As'eindicated in those gures, the con-l trol head comp/rises a body member 12 having an integrally formed tapered driving shank. 'I3-- thereon whichl is threaded as at 14 adjacent its point of connection with the body 12. The lower end of the body l2 is provided withan axially ex#- tending opening 15 terminatingat its upper end in a' spherical seat portion ll. The spherical seat portiorrl is bounded at its upperI end by acy- `lindrical opening 1l. A slightly smaller opening 18 extends upwardly from-the opening 1l forming a shoulderA 19 at the point of junction.' A still smaller opening extends upwardly from the opening I6 forming a shoulder 8| at the point of junction.v The upper end of the drive shaft 56 is provided with a spherical enlargement 82 which seats against the spherical surface 16 and is held against axial displacement by means of the split seat members 83 whose marginal flange isn75 der 8| and Washer 89.

clamped against the lower face of the body'12 by the ange 84 ofthe cap 85 which is threaded on to the exterior surface of the lower end of the body 12.. kThe spherical end 82 is slotted as at 88 and the body 12 vis diametrically `slotted (not shown) from its lower face to theyshoulder 18. A washer member 88 is received in the opening 11. This washer member 89 is provided with wing portions 90, as best shown in Fig. 9, in. a manner similar to wings 8| on the washer 62 as previously described, .the wings 80 being received in the groove 88 of the spherical end 82, and also in the diametric slo't just described' in the lower end of the body 12 so as to secure the drive shaft 58 to the body 12 for equal rotation therewith. The wings .90 are -each provided with an outwardly extending lug portion 9| which project out past the outer surface of the body 12 and are engaged by the-nut member 93 which acts to dlampthe washer 89 against thevsh'oulder 19.

The nut member 93 may be prevented fromrotating relative to the body 12 in the `manner indicated in'Fig. 5 which is as follows:` .The cap member 05 is provided with an opening 94 therein positioned parallel to the axisthereof. Within the opening 94 isslidably received a plunger 85 which is constantly.,urgedupwardlyby the coil.l spring 88. The lower face of the nut member 83 is provided with a plurality, ofdepressions 81 which are engageable in turn by the plunger 85, the depressions 91 being equally spaced from the axis of the body member 12. Y y

vThe construction of the controlhead thus far described provides means for driving the drive shaft 58 from the spindle 13 throughia connec-y tionl allowinguniversal movement between `the two. The means for controlling the rotatable y position of the square shaft 55 which controls` the position of the cones 25 and 28 .relative to vthe body member 12 will now be described. .The

square shaft 55 projectsup. through the shaft 58, through the washer 89 and into the opening 80. Surrounding the shaft 55 withinthe opening 18 and non-rotatable relative thereto `is a spur gear 98 held against axial movement between the shoul- The body 12 is provided with `three equally spaced slots 99 in the same transverse plane as the opening 18,`the slots 88 opening into the opening 18, as best illustrated in Fig. 6. Received in each of the slots 99 is a spur gear in mesh with the gear 88. The gears |00 are each maintained in proper spaced rela'- tionship with respect to each other by means of axle pins IOI whichare rotatably received in the slots |02 extending inwardly from the outer sur'- face of the body 12 perpendicularly'to and centrally of each of the slots 89. Rotatably surrounding the body 12 above the nut member 83 is a collar |05. The collar I`ls cut away internally at its lower end as 'at |08 to"` provide clearance for the ends 9| of the'washer member as, and

also to receive therein and in which is secured an internal gear |01which mesheswith each of the gears |00. The opening `8II is considerably larger than the shaft 55 which is received therein. and which shaft receives the gear 88, so that the gear 98 floats between the gears |00, thereby insuring equal turning effort being transmitted by each ofthe gears |00 to the gear 88. It will be apparent that if the collar |05 is rotated relative to the body 12, the internal gear |01 in rotating with the collar |05 will cause rotation of the rgears |00 which. in turn, will cause rotationof the gear 98 and consequently the shaft 55, and that when the shaft 55 is rotated it causes rotation of the screw 45 in thegrinding head and thereby imparts axial movement to the cone member 24 in order to cause an increase or decrease of the effective diameter of the grinding .head in accordance with the directionof rotation of the shaft 55. This relative rotation ofthe collar |05 on thebody 12 may be accomplished during rotation of theY body.

12 `by frictionally opposing rotation of the collar |05 simply by grasping the collarr |05 by the hand, or else a brake bandsuch as |08 may be provided with suitable means formanually drawing it into contact with the `collar |05 to frictionally resist rotation of the latter. However,`

unless some means were provided for limiting the amount o f rotation of the collar |05 relative to the body'12 during rotation of the body 12, as thus described, it will be apparenty that itwould be impossible ltoaccurately control the maximumy diameter to which the grinding head would consequently be expanded. Adjustable, means are th'erefore provided for'limiting the relative rota'- tion of the collar I05'relative tothe head 12 in the following manner. e Y y The upper surface of the. head 12 isprovided with a washer member IIOY which is secured against rotation relative'thereto by screw means such as III The washer member IIII'proJ'ects laterallyv beyond'the surface of the body '12 and 'bears againstthe shoulder II2 formed `on the collar |05 so as to restrain the collar |05 from movement in that direction. A nut member ||3 is'threaded onthe portion 12 of the spindle 13 and its lower facev bears against the washerI I0 to4 thereby lock it against rotation. Rotatably surrounding the nut member ||3 is a collar member I4. The washer I I0 is prbv'idedfwith a relatively.

great number of openings I 5 therein disposed parallel to its axis and all of whichare disposed at an equal radial distance `from its axis. The collary I I4 is provided with apin member |I8 which pro-K` |I4 and are constantly urged upwardly by the` springs II9, the plungers II1' bearing against the K under face of thefiangedpo'rtion of the nut II3.v

If it is desiredto change the rotatable position of the collar II4 relative tothe head 12, the collary II4 may be raised against the pressure of the spring plungers ||1 until the pin |I8 is lifted above thewasher IIO, afterwhich the coll'ary II4 may be rotated to the desired position and the spring plungers I-I1 then be allowedto yproject the collar` II4 back` toits normal position with the pin I I8 received in the opening I'I`5`determined by the rotatable position ofthe collar lI I4. `The collar I|4 isfurther` provided with an `outwardly projecting'lug |20 andthe collar |05 is provided with a pin |2| which projects upwardly fromits.

upper surface intothepathof the lug |20.V Froml this it will be apparent'that inasmuch as the collar II4 is -xedfin any one ofvits rotatably ad; justable positions relative to the bodyv12, `the lug lzo `is likewise fixed reattive to the body' 12. The

pin |2I in projecting into the path of the lug |20 and 'itself having. a relative movement in the plane ofthe lug limits the rotation of the collar |05 from a position where'the pin |2I lbears against one side of the lug |20 to a position where it bearsagainst the other side of the lug I20,- or,

in other words, an amount equal to one complete revolution of the collar |05 minus the width of the lug |20 andthe diameter of the pin |2|.

In actual operation the ratio between the various gears 98, |00 and |01 and the pitch of the screw of the grinding head are so proportioned that the allowable rotation of the collar |05, as limited by the lug |20 and pin |2|, is such as topermit the grinding head to be sufiiciently contracted after finishing the bore of one object to allow it tobe inserted into the bore of the next like object to be worked upon, andl then be expanded to the maximum diameter required. By this means, when the device is being employed for grinding a great number of bores of equal diameters such as occurs in the production of automobile cylinders, the collar |05 is rotated to contract the grinding head to the smallest diameter permitted by the position of the lug |20 and pin |2| so that it may be inserted in the bore of the work, and then by frictionally resisting rotation of the collar |05, during rotation of the grindinghead, bythe brake band |08 or by the hand as described, asgreat an expansion of the grinding head as the lug |20 and pin |2| will permit is caused in order to obtain the desired maximum diameter of the grinding head necessary for the work being done.

As the abrasive elements 35 of the grinding head Wear during the grindingopeiation, it will be necessary that the position of the lug |20 relative to the body 12, be varied in order to permit a greateriexpan'sion of the grinding head to take up the wear,v and this is readily accomplished inthe manner previously explained by raising the collar ||4 against the pressureof the spring pressed plungers and rotating the collar 4 sufficiently to permit the proper additional rotation of the collar |05.r Furthermore, theopenings ||5 in the washer I0 vmay be so arranged that when thepin ||2'is moved from one opening ||5 to its next opening ||5, the loutside diameter of the grindinghead will be permitted-to increase a denite and easily calculated decimal part of an inch in order thatthe operator of the device may accurately. gauge the increaseddiameter of the grinding head which will follow in 4moving the pin |6.from one opening ||5 toits next. l

From the foregoing it will be" apparent that this control means permits the'grinding head to v be expanded .during operation to a predetermined maximum dimension and furthermore permits adjustment of the control so as to maintain such maximum dimension at a constant value in order to compensate for the Wear of the abrasive elements.

Formal changes may be madein the specific embodiment of the invention described without departing from the spirit or substance of the broad invention, the scope of which is commensurate with the appended claims.

What I claim is:

l. In a device of the type described, in cornbination, a body provided with an axially extending bore, a pair of spaced cone members slidably received in said bore, means for controlling the position of said cones 'in said bore, said body being provided with two series of radially extending openings, a pin slidably received in each of said openings, the outer surface of said body being provided with grooves each of which'extends between an opening of each of said series, each of said pins being provided with a groove in line with the rst mentioned grooves,

a plate member positioned in each of the rst v of said cones in said bore, said body being provided with two spaced series of radially extending openings vleading into said bore and grooves in its outer surface, each of said grooves extending between an opening of each of said series of openings, said body being provided with a second groove extending inwardly from thebottom of each of thel first mentioned grooves, a pin in each of said openings projecting into the corresponding of said second grooves, asegmentally shaped member received in each of said second grooves and slidably bearing on the corresponding of: said pins, said members projecting into the corresponding of said iirst mentioned grooves, andan Vabrasive elementl received in said first mentioned grooves' in` co-operative relationship lith respect to the correspondingl of said memers. l

3. In a device of the type described, in combination, a body member provided with an axially extending bore, a pair'of iixedly spaced similarly facing cone members slidably received in said bore, radially extending pins carried by said body member having their inner ends bearing one or the other of saidcone members, abrasive members supported from the outer ends of Said pins, a rotatable member disposed axially of said bore having a screw connection with said cone members,'means for positively maintaining said romentv surfaces fixedrelative tosaid body member positioned above and below a head on said rotatable member and maintained in fixedspaced relationship with respect to each other by spacing means, and means for rotating said rotatable' member. y s

'4.y A control head for a grinding head or like devicecomprising, in combination, a body member, ahollow shaft adapted to be driven thereby, a `second shaft within said hollow shaft, a gear non-rotatably secured to said second shaft, a collar rotatably mounted on the outer surface of said'body member, an internal gear carried by said collar, and at least three gears interposed in an annular row between said internal gear and the first mentioned gear and in mesh therewith and operating to equalize the transmission of motion from said internal gear to the gear on said second shaft.

5. A control head for a grinding head or like device comprising, in combination, a body member, a hollow shaft adapted to be driven thereby, a second shaft within said hollow shaft, a gear non-rotatably secured to said second shaft, a collar rotatably mounted on the outer surface of said body member, an internal gear carried by said collar, and at least three gears interposed between said internal gear and the rst mentioned gear and in mesh therewith, said i'lrst mentioned gear fioatingly supported between said three or more gears.

6. A control head for a grinding head or like object comprising, in combination, a body member adapted to be driven by a suitable power lthe exterior of said bodv preventing rotation of said cap relativelyto means, a hollow shaft secured to said body member for driving movement therefrom, a second shaft within said hollow shaft, a gear secured against relative rotation to said second shaft within said body, said gear supported to float in the plane thereof, a collar rotatably mounted on member, an internal gear carried by said collar, and three or more gears interposed between the rst mentioned gear Vand said internal gear and supported to float radially of said body member. n

7. A cylinder grinder comprising a body provided in its lower end with an upper seat, av

bushing arranged in the lower end of said body and provided with a lower seat, a shaft provided with a sphericalenlargement engaging the upper and lower seats and an abrasive element operatively connected with said shaft.

8. A cylinder grinder 'comprising a body provided in its lower end with an upper seat, a bush` ing arranged in the lower end of said body and y provided with a lower seat, a shaft provided with a spherical enlargement y lower seats, a vcap connected with said body and engaging said bshing for holding the same in neoied wiihsaid shaft.

1o. 1n e cylinder grinder, e pody provided in its lower end with an upper seat, a bushing arranged in the lower end of said body and provided with av lower seat, a shaft provided with a spherical'enlargement engaging the upper and lower seats, a cap having a screw connection with said body and engaging said bushing, andemeans for preventing rotation of said cap relatively to said body, in-

cluding a member arranged on said body and provided with a Lplurality of depressions, a plunger mounted on said cap and adapted to engage one.

or another of said depressionsand a spring for pressing said plunger toward said member.

11. In a cylinder grinder,

engaging the upperand e body provided with e seat and notches on diametrioauy opposite sides of said seat, a shaft having an enlargement which engages said seat and is provided on its diametrically opposite sides. with notches, and a cross piece arranged within the body and provided with a pair' of wings engaging -with said notches of the body and another pair of wings engaging with the notches of saidenlargement.

12. In a cylinder grinder, a body, a shaft connected with'said body, a collar rotatable on the exterior of said body, a -gearing operatively connecting said collar and shaft, a ring connected with said body and provided with a plurality of. openings, a stop collar adjustable about the axis i of said body and providedwith an adjusting pin adapted to engage with4 one or another o f said openings and also provided with a stop lug, 'and a j stop arranged on said body and adapted to be engaged by said stop lug.

13. In a cylinder grinder, arbody, a shaft con-I nected with said'body, a collar rotatable on the exterior of said body, a gearing operativelycon`v necting said collar and shaft, a'ring connected with said body and provided openings, a stop collar adjustable the'axis adapted to engage with one oranotheiv openings and-also provided with a 'stop lg, arranged on said adapted to be by seid stop iug, and meansrroryicldingly ing said adjusting collar inoperative" relational: said body and ring.

14. In a cylinder grinder, Mindy, nected with said body, a

exterior of said a gearing operatively con#l necting said collar withy said body and openings, a stop collar adJustable about thefaxis of saidbody and provided withanladjustingpinQ adapted to engage with one or another-of openings and also provided with a StOplu'g, a. stop j f arrangedon said body and'adaptedlto be kengaged lby said stop lug. and' means for yieldingly-I'r-il j taining said adjusting collar in operativerelation f f to said body and ring, including an simi` ment connected with said body, Dlungers mounted on said adjusting collar andengaging with'saidv abutment, and springs urging said plungers to-"` f .ward said abutment. -1 v BENJAMIN O. ISOM'.

withuajplurality of* -A `of saidbody and providedwitnm adjusting 7 l 35 and shaft, a ring;connected" provided witha pluraiityiofi 1 a

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