US1460724A

US1460724A - Grinding machine

Info

Publication number: US1460724A
Application number: US437541A
Authority: US
Inventors: Mcgrath John Thos
Original assignee: Individual
Current assignee: Individual
Priority date: 1921-01-15
Filing date: 1921-01-15
Publication date: 1923-07-03
Anticipated expiration: 1940-07-03

Description

July 3, 1923.

' J.l T. MCGRATH n "GRINDING MACHINE Filed Jan. 15. 1921 5 sheets-sheet 2 July 3, 1923.

L 1,460,724 J. T. MCGRAI'H GRINDING MACHINE Filed Jan. l5 1921 5 Sheets-Sheet 5' 67- 75 A v V |10 1.

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65 36 l F" A f d i da' 06 g3 .72 70 gy ax??? 96m# July 3, 1923. l1,460,724

J T. McGRATH GRINDING MACHINE Filed Jan. V15, 1921 vsheets-Sheet 5 Patented July 3, 1923n i ILLINOIS;

GRINDING MACHINE.

Application filed January 15, 192i.

To all whom t may concern.'

Be it lrnown that l, loi-IN THOMAS Mo- GRATH,`a citizen of the United States, and a resident ofBloomington, in the county of McLean and State of Illinois, have invented certain new and useful ,improvements in Grindingh/fachines; and l do hereby declare that the following is a full, clear, and exact description thereof, reference being had to the accompanying drawings, and to the characters of vreference marked thereon, which form a part of this specification.

My invention refers to improvements in grinding machines and, as herein disclosed, has been designed as a universal machine for the purpose of grinding the steam feed pipes and connections for locomotive boilers at the vparts thereof where steam tight connections are formed between the various elements of the connections; that is to say, the machine is designed for grinding the seats at the ends of the various pipe and joint elements of such steam connection, including the steam pipe, dry pipe, nigger head, `the.

branches that lead from the nigger head to the steam valve chests, et cetera. lhile the entire machine has been designed with particular reference to grinding, such steam pipe connections for locomotive boilers, and in itsentirety is adapted for properly attending Vthe various connections mentioned, it will be understood that, sonfar as the .broader phases of the invention are conworlr is sustained during grinding and the means for giving said support its movement of grinding and lifting;

' An object of the invention is to provide a l grinding machine having very simple mechanism for supportinwthe element to be ground in suitable coactive relation with@ grinding tool or in vposit-ion to coact with another surface to be Ground when the `oint surfaces or two pipes; or connections are to i be ground by, moving'one surface in grinding relationwith its mating surface.

Another object of the. invention is to provide in a machine of-this character means,y

whereby the two elements to bemanipulated, the tool connection and. pipe member, or two pipe members, can be maintained in proper axial relation withrespectvto the bore of the pipe or center oit-other work to be ground.

serial no. ear/,541.-

so constructed and is connected withjthe base of the machine and related tothe support for the rocking tool or work as to properly support different shaped pipes, joints,

i,4go,724'

and like connections in the machine while? the jointsurfaces are being ground thereon.

@ther objects of the, invention are togenerally improve and simplify machines of this character, with the. end in view ofuniversally adapting the machine to different Work and enabling the .work to be manipulated and ground by relatively -unskilled labor. i ofthe machine; y i 2 Figurel is a side elevationof a grinding machine embodyingv my invention;-

YFigure 2 isa front elevation thereof with parts brolren away.,

Figure 3 is asection on the line 3-3 of Figure l. y n j Figure t is a section on the lille dre-4; of Figure 2. i n p Figure 5 is a view, partly in side elevation and partly in section, of the lower part of themachine, showing the machine adjusted to grind the central branch of an angle fitting o r nigger head constituting one of the elements of al locomotive boiler steam connection. *j i Figinre 6 is a horizontal section on the line G--ti of Figure 5. l

Figure 7 is a side-elevation of the machine,

showing` it adjusted to grind one of theend seat faces of anv angle fitting or nigger head. Figure 8 is a detailof the `tool employed in the'adjustment shown in Figure 7, as wellv also asthe adjustment shown in Figures l and l2, hereinafter to be described.

igure 9 is a detail view illustrating the valve for pneumatically `lifting the 'work supporting` table and the mechanism for controlling Said valve. fr. I c f Figure l0 is a side elevation of the machine, showing it a'djustedfor grinding the ln the drawingafshowing one embodiment joint between'the short stand pipe andthe horizontal dry pipe of the locomotive boiler.

Figures ll and 12 illustratethe machine adjusted for grinding the respective oppOSte ends of the steam pipes connected to the steamchests.

As shown in said drawings, 15 designates the base of the machine. 16 designates an upright column thereon, shown in Figure 6 as being hollow of oblong cross section. 17 designates an oscillating table which, in some of the adjustments of the machine, supports parts of the work and in other adjustments rsupports a tool which operates in connection with the work. rlhis table is given a short rocking or rotativo oscillatory motion about a vertical axis from a mechanism hereinafter to be described. 18 designates a cylinder which contains a piston 19 and the table 17 is supported on the piston through the medium of a piston rod 2O that is attached to the piston and extends upwardly through stuiiing box 2l in the lupper head of the cylinder. There is preferably a loose or ball joint connection, indicated at .22, between the table 17 and the piston'rod 20, which permits the part that is supported on said table to align itself relatively to the part with which it coacts, as will hereinafter appear, to produce a true ground joint. This ball joint connection can be produced by providing a ball at the upper end of the rod 2O toenter a socket in an extension 23 on the lower sideof the table, and said extension and an adjacent top part of the rod 2O can be' relied upon to prevent the table tipping when in its loading position, and which is its lower position, as shown in Figures l and 5.

Assuming that the work to be ground is fixedly supported by suitable device above the table and in vertical alignment with the table axis. it is to be understood that the work, when so supported, is located with its lower end a distance above the table greater than the length of a tool and its adapter, or the length of a pipe or a pipe and its adapter, that are to be severally supported on the table to partake of the oscillatory movement of the table to grind the joint on the supported pipe. This is to enable the grinding tool and its adapter or a pipe connect-ion to be fitted upon and locked to the table, to have ample head room beneath the overhead supported work. Thereafter the table and parts supported thereon are lifted by pressure applied under the piston 19, in a manner hereinafter described, to bring the tool and work to be ground or the two surfaces of the work to be ground into proper grinding relation to each other.

After the table andvwork or tool sup ported thereon has been lifted to its operative grinding position with respect to the fixed work support on the machine, in the .manner to be hereinafter described, rotary oscillatory movement is imparted Y to the table by means made as follows:

Said. table is provided at one end with an extension or arm 25, (Figures 1, 2, 6 and 7) having a vertical opening provided with interior point bearings for a vertically swings able -rod 2G, -which extends therethrough. Said rod is swiveled at its lower end to suitable bearingv 27 fastened to the base, the swiveling connection embracing a head 28 on the lower end of the rod and suitable spherical socket in the bearing 27. The rod 26 is also provided at its upper end with a like ball or spherical bearing 30, which is adapted to fit within a spherical socket 31 carried by the outer end of a link 32.'

The other, or inner end, of the link 32 is connected by a crank pin 83 withv a crank disc Se that is rotatably mounted on a stud 35 fixed in any suitable way to the supporting column. The said disc 34 is peripherally geared to mesh with a pinion 36 which, as shown, is fastened on the armature shaft of a motor 37 that is supported on a bracket 38 ixedto one side of the.

disc Siand the connections of the link B2- to the swinging rod 26, relative to the' counection of the latter `with the table, are such as to give relatively short arcs of oscillatory movement to the tableand the work carried thereby.

Preferably the means which deliver* a lift y ing fluid under the piston 19 to ylift the table an d the parts supported thereon to, operative grinding position can be operatively connected to the means which give oscillatory movement to the table, so that thereby the period of contact of the grinding surfaces can be determined with respect to the number of oscillations of the 'table derived from the mechanism described. le., suitable timing mechanism for the grinding operatiomwhich serves to admit fluid pressure under the piston to raise the table andparts supported thereby at the properctiine to release said pressure to permit the table and the parts supported thereon to descend to the lower or loading position of the table, is herein shown and is made 'as follows:

e() designates a link which is loosely connected at its outer end at 4.1 to the swinging rod 26 between the plane of the table, when in its loading position. and the upper bearing end 30 of the rod.l Saidlink is loosely connected at its other end to a swinging pawl carrying frame or lever l2 that is pive 19 thereof.

oted on shaft 43, which latter is mounted in an upstandingirarm 44 on 'a :Valve casing or boX45, as bestshown in Figures 1,3', and 5. Hinged tothe Vframe 42 .is a pawl 46, the tooth or" 'which engages-a a ratchet wheel 4T that is 'fixed to said shaft 43, so esito-cause thesha'ft tol rotate therewithl as the 'ratchet wheel is stepped forward by the pawl.

48 (Figure '9) designates `a cam `disc also iXed on 4the shaft 43. Said cani disc is disposed in .thgplaneof thevertical aXis of the rallye casing 455 ,It is '-peripherally concentricto its'aais offrotation throughoutthe principal portion of its circumference1 and yis provided with a'rel'ativelyshort drop 'or depression 50' which cooperates with the stem ofl and operates a Valve' within the casing` 45frto admit fluidl 'under pressureatfthe propertime under the vlifting' piston 19, and now to befde'seriloed.

The valve casing isfdiyided into upper. and y lower` chambers l5.2,' 53. `The upper' chain-v ber is an exhaust chamber, andthe lower chamber is adapted lto be vconnected,i-below;`

a' valve therein,""byl a Valvedpipe 55 to a' source of fluid under pressure',-notshown 54 designates .a valved l'pipewhich lconnects the upper or exhaust'chamber 52 with the table raising cylinder 1'8 below the piston 56 designates a diaphragm which separates the'cha'mber's' 52 and and is" provided with a communicating port`57.

`Said port is normally closed by a 4valve 58,

shown as having the i'orin of a disc Valve and normally held by a suitable' spring agrainstthel 'lower 'faceof the 'diaphragm' 56 toi close thef port .57." Said casing is also provided withlan exhaust port' 'or passage 52 which connects thevexhaust chamber 52 of the -Valve 'casing' tothe atmosphere. i

Said disc valve 58 is formed on or fixed to `a stemV 59 that is guided` at its lower end in a socket 60` formed vinrtheloiizerwall :oit the lower valve chamber, and is "guided at its upper end in a socketed` enlarged `portion 61 of an extension stern' 62, which extends tliroughlthe upper wall'o'f rthe valve casingl Jfor Contact4 with the periphery of the

camv

48,7 before described. A rather strong initially tensione'd spring '64 snrroi'inds` the valve stem 59 between the end wall of the lower chamber and the Valve disc 58 to normally hold the Valve in position to close the port 57. The upper of the valve stem 59 bears against a lighter compression spring which.y is interposed between itv and vthe Vend wall of lthe socket formed in the enlarged 'porticn61-0 the ylower end of the extension stem .62, said enlargedfportion 'con- Stitutinn'y a piston element that operates in asuitable cylinderx61f=to control the eX- hanst port 52 ln the operation of the lifting mechanism described, when cooperating with the means fol'- giving loscillatoryv movement to thetable',

the shailtll, carryingI the Cain 498, is steppifl forward an' angular' distance equal'to. l'he angular dimensionoit' a ratchet ftootln nWhen the canrdisc 48 has-beensteppedforwaid 'to bring its raised lportion 48 into contact with the valve extension stein62, 'said raised portion of the cam iirstu'acls' to oroesaid extension ldownwardly against the action of the spring 65, `This vmovement initially closes the upper or exhaustfchamber outlet` port, 52 before pressure is exerted to overcome the spring; 64. Thereafter, in the fur! ther descent of the `valve rod extension',` the l spring 65 is ifullyccompressed so' that end# wise movement is given 'to thev i/*alye'ste'inI 59 to nieve the valve oil its seatand to 'estabilish Vtlow `for vflui'd under 'pressure from the .lower or pressure chamber,'tlirough the Valve' port 57 'and 'pipe 54 beneath the lifting" piston' 19` in the' cylinder 18, to lift 'the tabl'el17,

vSO

andthe parts supported thereon.' The saidv table will beheld in its lifted position dur'- ing Vthe time the, cam projection' 48, of the ratchet actuated cam'y disc" is engaged vwith" the valve extension 62, inasmuch asat'this4 time the portv 52"v is `closed by the member 61 and the lfull fluid pressureofthe sourcev is exerted under the lifting piston 19 The peripheral length ofthe raised' portion 48 of the cani 48 is such as to nire aisuliicie'nt' j thej grii'idinirr.-

period .ot time 'for effectii' operation on the work.' .f'rliiter the cam-48?" f has passed off or away from they valve-stem extension 62, the 'stronger springr 64,' assisted by' `air pressure from chamber 53, raises the valve disc 58to its seat` and closes 'alltlieL loo connection between the pressure source and .if

the bottom otI the cylinder At'thistinia` by reason 'ofthe expansion ofthe spring 65,1

the enlargement o'lI the valve rod extension 62 has been'foreed'upiiiardly to` uncoyerthe exhaust passage 52" to permit air tofes'cape' allow thelilitinpfpiston to descend. y s, Theperipheral length of the` cam disc de from the bottom of said cyliiiderl andwt' pression50 lcan be determined byl the'charf iio acter` of the w'orlrbeinsiV operatedon, so as' to v work in a machine orto apply4 Igrinding` compound, such as einer;T rand oil and to allow the `grindingl compoi'ind to` properly adjust itself on'tlie v'work' faee'or faces being l ground. ,Y

The construction sof'far described'consti-- tutes the operative' elements' to 'lift the table 17 and partssupported thereon and to oscil,

late them durii'ig griridinf?r operation. "ln'y addition to this mechanism, the machine ein-N I braces means for supporting andA iixedly holding the werk in position over and upon the table while being' nroiind. `Th e'fconstruction described hasbee'n designed to produce what may be ter'med a-universal machine, in that the work holding means that hold the work upon and above the table are constructed to support work that varies considerably in the vshape` and dimensions thereof.

rlhe work holding means embrace, in part, suspension means that rise aix-oye the column 16 to suspend some ot the shapes being ground, in combina-tion with means supported rigidly on said column to hold the suspended work in tired position. F or some kinds of work the suspension means need not be employed, the fixed supporting means at the standard being suiiicient.

Referring now more particularly to the detail of the entire supporting means, the same can be made as follows:

67 designates swinging or rotary crane mounted ina socket 68 of the column 16., lt hasat its top a horizontal jilo 69,braced ltherefrom by a brace 70. 71' designates a trolley which travels on said jib and from the trolley is suspended a block and tackle 72 tor raisin@` and lowering and tor sua-- porting a slingr clampv 7 3. A cable 7a, trained about the pulleys oi the block and/tackle, is adaptedh to be attached at 75 to the crane member `to hold the sling clamp and .the work engaged therein at a. desired height. 77 designates a work holding plate which hinged to a stud 78 that extends transversely through the top ot the column 16. Said plate is provided at the front end of the machine with aange or head 79 that termiw extends the clamp and provided at the other side thereof with lugs to receive alclamping bolt 86. 87 are centering screws which are threaded radially through the clamp members for impingement against the work. as the pipe A shown in Figures 1, 2, and 1. The work A shown in the last mentioned iigures is the long horizontal dry steam pipe ot a locomotive boiler that is located in the top ot the boiler between the stand pipe in y the steam' dome and the nigger head D at` the trontot the boiler that connects saidv dry` steam pipe A with the steam chests ot the engine.

The same form oftackle or clampV arrangement can also be used with the branch pipes C leading trom the nigger head D to the'steam chests and for grinding the joints at both ends thereof, as indicated'in Figures 11 and 12. So also vthe same tackle and clamp arrangement may `be'used tor 'grind-y 7 i ing the joint between the lateral branch a of the dry steam pipe A. and the-steam pipe E, as shown in Figure 10, in which arrangcl ment it will be observed that the swinging or rotative crane hasl been Aswung to carry the. jib in the opposite direction tromthat shown in Figure 1, so that the sling clamp 73 supports one end of the pipe while the other end thereof is` supported inthe clamp 82. The swinging crane 67 is ott-set at 67 to admit ot this last adjustment,`.as

indicated in Figures 1, 10, 11, and12.l 'lhisy can be eifected by providing the'swinging plate 77 with'gear teeth to .mesh with a pinion 9() that is `fixed to a shaft` 91 which is rotatably mounted inthe column 16 andl is provided with a crank arm 92.

The said plate 77 can be angularly arljusted by turning the shaft 91 and can be held in any adjusted position "by a locking pin 93 which is adapted to passthrough registering openings' in the walls ot the hollow column 16 and to severally engage suitable openings 94 in the plate 77 which/are severally adapted to register with the pin in different positionsv ot adjustment o1v .the plate` Las will be clear trom an inspection ot Figures 1, 10, 11, and 12.

ln an adjustment Jfor grinding the joints at the ends ot the body of the nigger head D. as shown in Figure 7, an adapter fitting 95 takes the place ot' the clamp fitting 82, before referred to` and is provided with a iiafnge 96, to which the flange ot the central branch (l of the nigger head can be bolted to hold it in position for the grinding operation.

In Figures 1, 2, and 3, the niggerhead D is adjusted to grind the seat at one end of the branch 0l. This grindingv is effected` between said seat and a seat on theadjacent or forward end of the main dry steam pipe,

which, in the adjustment showny in Figures 1 and 2, is supported bythe iXed and sling'` normal forward end ot the pipe and the nig-y ger head D are groundby pressing the joint faces together, which occurs when'tliey nigger head is `lifted by the lifting mecha#l nism described and thereafter oscillating the table 17 andthe nigger head vcai'riedV thereby.

Such grinding of a joint between partsv which normallyffit together, as a connection in the llocomotive boiler, occurs `also when grinding the joint between the lower'endl of the branch' a of the dry' steam pipeA` and tlie lower end of the short stand pipe E, as shown in Figure 10, in grinding adjustment. This short stand pipe in the locomotive boiler is a connection between the drysteam pipe and the throttle valve box in the steam dome of the boiler. The said stand pipe is shownv in Figure 10 as supported onI the table 17 through the medium of any suitable adapter piece 100, which canbe fixed in any suitable manner to the table and can be flanged and bolted tol the flanged end of the stand pipe. l

InFigure 7 the joints at the ends ofthe main body of the nigger head are ground by a grinding tool designated as a whole by101, wherein 102 designates a grinding ring of proper cross section and is vsupported on the upper end of a post 103. vSaid post can be fixed at its lower end. in any suitable manner tothe table, as by means of a flanged member .104 that may-be bolted to the table. In the arrangement shown in Figure 7, the

Y suspension means, embracing the swinging crane jib and the block and vtackle devices, arefnotnecessary. The said grinding ring 102 of the tool 101 is shown as loosely sup` ported on the upper ends of spider arms 105, suitably offset at said yupper ends for interlocking engagementwith the inner vface of the ring, and are hinged at their lower ends to lugs 106 of a nut 107 that is threaded to the-upper 'end' of the post 103. Said nut, and, therefore, the grinding ring 102, may be vertically adjusted on the post 103 by means of the threaded adjustment described between the nut 107l and post 103.v The spiderarms 105 can be thrown outwardly against the inner face of the ring to hold the ring iixedly on the spider arms by means of a collar 108 that is threaded to the post beneath the nut 107 land is provided with an outwardly `flaring vor .bell shaped upper ange 109 to engage the terminals 110 of thearins 105l below their hinge points, as clearly indicated in Figure 8, the arrangement being suc-h that the upperl ends of said arms are forced outwardly into holding en? gagement with the ring when the-collar is threaded upwardly relatively to vsaid termina-ls. The post 103 ofthe grinding tool may be provided with adapter sections 111,

as indicated inFigures1-1 and12, to adapt` the tool head, when grinding position, to the work being operated upon.

It will benoted in Figures 11 and 12 l'of the claims hereto appended,land that that the sling clamp 73 andthe clamping i.

ringy 82 can grasp `and hold the workk at relatively different points ofthe pipeswwllilen grinding the two ends thereoffwhil'e ab 'the same time presenting the axis of the'te r. minals' of the pipes `being.;ground ico-'axial to the axis of the grinding A toolrV Thereafter the seat 'faces will be properly presentedto the tool. ln the same manner the steam ypipe is ysupported for, grinding the joint faces between one end of the pipe andthe nigger head,` asshown in Figuresl ande,

and the other lbranchedend ofthe said `pipe and. the stand pipe E, as shown in FigurelQf The foregoingindicates a universal ma` chine jfor grinding the 4joints between the several pipes and angle connections of la locomotive boiler in a mannerth'at permits the different parts to be accurately presented to an opposing grinding surface of ay' tool, pipe, or fitting. l aid vconstruction also enables the different parts to be'l quickly and readily applied tothe machineand fixedly locked in place whilel a joint is being ground. They serve merely as illustrations of the universaliadaptation of afinachine constructed in accordance withmy ,in-H vention to works of varying shapes'and sizes, and from what hasbeen said, fit1will` f be readily .apparent that joints nfiayfb'e,v

ground on manyl other'different kinds Aofy set forth comprising a table capable of hori- .y -zontal rotative oscillationv and adapted to support a grinding element, means to support' the work in line with the@4 grinding element, freely tiltable rvsupporting meansffor .1*-

said table at the axisof oscillationl thereof,

means to lift'the table to bring the grindf" ing element intovoperative relation to the work, and means for imparting to and fro oscillatory in a. horizontal plane. l

2. A grinding machine for the purpose grinding movement to said ltable Vset forth comprising a table capable of liori-.` 1

Zontal rotative oscillation and adapted'to 1.

.support a grinding element, overheadgmeans to support the workin line with the grinding element, means to lift the-'table to bri-ng' the grinding element into` Voperative `'frelaQ` tion to the worlgand freely tiltablefsup-.f 'porting means for said tableat the axi'sof` .oscillation thereof, means Afor imparting to and fro oscillatory grinding movement to said table in a horizontal plane, said latter means comprising a swinging member opera-tively connected to said table eccentrically to its oscillating aXis, and power means to vibrate' said member.

l (3.. A grinding machine for the purpose set forth comprising a table capable of rotative oscillation and adapted to support a grinding element, means to support the work in line with the grinding elements means to shift the table to bring the grinding element into operative relation to the worlr, and means for imparting to and fro oscillatory grindingmovement to said table, said y table being supported by means permitting the table torock about its a-Xis of oscillation tov automatically center the'grinding element to` the work.

4. In a grinding machine for the purpose set forth, a support for a grinding element, a support for the work and means operative from a single source of power for imparting rotary oscillatory movement to said support and for automatically controlling means .to lift the support towards an operative grinding position.

5, A grinding machine for the purpose set forth, comprising a table substantially in a lfixed plane capable of rotative oscillation and adapted to support a grinding element, means to support work in line with the grinding element, means to lift the table to an operative grinding position, means for imparting to and fro oscillatory q movement to said table, constructed to control the lifting movement ofthe table.

6. A grinding machine for the purpose set forth comprising a lifting cylinder, a piston therein having a piston stem, a horizontal table supported by theupper end of said stem by means permitting slight tilting movement of the table relatively to said stem, means to admit fluid beneath the piston to lift said table, and means for imparting rotative oscillatory movement to said table and operatively connected to the fluid n admission means.

7; A grinding machine for the purpose set forth comprising a cylinder, a piston therein and its piston rod, a table supported on the rod through a swivel connection, means to admit fluid beneath the piston to lift said table, and means for imparting rotative oscillatory movement to said table.

8. A grinding machine for the purpose set forth comprising a cylinder, a pistontherein, a table carried by the piston, means to admit fluid beneath the piston to lift saidtable andl forth comprising, inv combination with' over* head means for supporting work, and an os cillatory table to' support a grinding element in line with the overhead work, of a member having swinging connection at one end to a fixed part and operatively' connected to said table, means operatively connected to the other end of said swinging member to give oscillatory motion to said member and therethrough to the table, and means for lifting and lowering said table relatively to an operative grindingy position.

l0. A grinding machinerforA the purpose position, and means connected to said swinging member for controlling the lifting 'and descending movements of said table.

ll. A grinding machine .for the purpose set forth comprising, in combination with overhead means for supporting work, and v a table to supporta grinding element in line with the overhead work, of mechanism to impart oscillatory movement to vsaid table, means for lifting and lowering said table relatively to an operative grinding posi-A tion, said lifting means embracing a cylinvder, a piston therein connected to said table,

valved meansto control the flow. of fluid into the cylinder beneath said piston, and means associated with the mechanism for giving oscillatory movement to the support for controlling said valve means. f l2. A grinding machine for the purpose settforthcomprising, in combination with overhead means to support work, and an os` cillatory .table to support a grinding .ele-V ment in line with the overhead work, of` means to impart oscillatory movement to said table, a cylinder, a piston therein to support said table, fluid pressure means for lifting the support and provided with a controlling valve, a pawl and ratchet mechanism forcontrolling said valve, and means to operatively connect said pawl and ratchet y mechanism to the means to oscillate the table.

13. A Lgrinding machine for the purpose set forth comprising means to support over i head work, a lsupporting tablev beneath the work position, mechanism forV imparting rotative oscillatory movement to the table, and means for raising the-tabletowards,

operative grindingposition, permitting it to:y Y

descend to a lowerposition, embracing-a cylinder having a rod tol support said table at its upper end, a lcontrolling valve con-v nected to the cylinder below the piston, said valve having an actuating stem, a rotative cam adapted to actuate such stem, and pawly and ratchet mechanism associated with said cam, with'means to operatively connect said mechanism to `the means which gives rotaryy 15. Agrinding machine toi the purpose set forth comprising a base, a fixed column thereon. a cylinder supported on the base, a piston in the cylinder having a rod er tending upwardly therefrom, aworktable supported by a ball joint on said rod, a rotative Crank disc mounted on the column and operatively connected to the table to give it rotary oscillatory movement, fluid pressure means to control the. rise and descent of said piston, valve mechanism for controlling passage of fluid under pressure to the cylinder beneath the piston,` and means operated by themechanism for oscil-I lating said table to control said valve mechanisi n 1G. In a grinding machine for the pur-K, pose set forth, a support for a grinding ele-- ment, means operative from a single source of power for imparting rotary oscillatory movement to said support and for controlling means to lift the support towards an operative grinding position, and an upper work holder above said support pivotally mounted by means to permit the work holder to assume varyingangles to the `plane of said support, with means to lock the holder in adjusted positions, j

17. In a grinding machine for the purpose set forth, a support for a grinding element, means for imparting rotary oscillatory movement to said support, means to lift said support towards an operative grinding position, a work holder above said table comprising a clamp to engage the work, a swinging gear element rockingly supported on a fixed part, `and a rotative pinion meshing with said gear element.

18. In a grinding machine for the purpose set forth, a support for a grinding ,element, with means to impart grinding movement thereto, and means to raise said sup port to operative grinding position, a work holder above said table comprising a clamp toengage` the work, a swinging gear ele-v ment to which'said clamp is fixed; and-da'y meshingjwith said gear elerotative pinion ment.

' 19. In a grinding machine for the purpose vset forth, a supportfor a grinding element with means to impart grinc'lingmovementl thereto, and means togr'aise said supportto operative grinding posi'tioin', ywork holder above said table comprising a clamp to en-A gage theworlna swinging gear'element to which said clamp isfixed, a rotative'pinion meshing with said lgearv element, and an.

overhead crane and jib'l carrying a sling' clamp to'sustain a portion of the overhead work so supported by said clamp. v

20. A grindingmachine for the` purpose set forth comprising a column, a work clamp.

having means toangularly and adjustably support'it on said column, a work tablevbelow the work clamp, andfineans for impart` ing rotary oscillatory-movement to thetable, combined with means for lifting the table vtowards its operativegrinding position.

21. A grindingmachine comprising a column, van adjustable woi'k holder at the up- `per end of the column having means to vary its angle to the vertical,I a grinding table below said work support embracing a lraislable` and lowerable )late','ineans to control the Iraising and lowering of the plate, and means to impart oscillatory movement to said plate comprisinga vertically' oscillatory member hinged at its lower end toa iiXed ,j

part and loosely connected lbetween its ends to a part of the table eccentric'to the axis of oscillation of the table, a rotative mem`` Y ber mounted on saidr column and alinkI coni iiected eccentrically to said rotative 'member and having a hinge connection withthe up-. per lend of said verticallyloscillatory mem-- 22. A grinding machine comprising a column, an adjustable workholdervat the-up` per end of the column having means to vary its angle to the vertical", a grinding table below said work support embracing a raisi able and lowerable plate', means to control the raising and lowering of the plate, and means to impartv oscillatory movement to said plate ,comprising avertically oscillatory' memberhinged at itslower "end, to a fixed lpart and looselyconnected between its ends to a part of the table eccentric to the aXisf of oscillation of the table, aV rotative meinber mounted on said column and means con-' iio izo neeting said latter member tothe plate raise ing and lowering lControl to actuate the lat-` v ter.

In witness whereof I claim the foregoingl as my invention, I hereunto append my signature this 21st-day'of December, 1920.

.ionN irnos Moen/irri.