US2630353A - Way construction for machine tools - Google Patents

Description

March 3, 1953 w. E. RUTZ WAY CONSTRUCTION FOR MACHINE TOOLS Filed June 22, 1949 9. m 5 (M a W ;l% a (la win, 2 r a? Z 5 R n m. w fil [j Patented Mar. 3, 1953 UNITED STATES PATENT OFFICE WAYICONSTRUCTION FOR MACHINE TOOLS"? William-E; Rutz; Fond du Lacrwis zassignor 101 Giddings it &, :Lewis Machine: Tool Company, 1 Fond du Lac -l Wis a corporation of Wisconsin Application June 22; 1949, Serial No. 100,579

The: invention relates Veto: the :aconstruction 10f; ways for machine tools and. it isxmoreaparticus larly concerned with ways which are-madesepae e rately from and later assembled with .the.:bed,,0r other supporting: structure .of themachiner;

It is commonpractice inthemanufacture of relatively small machine tools such aszlathes .to provide a way, elements separable ;from .thezmaechine bed; s01 that they may; be machined :hand': finishground .by conventionaljmachine tools and; may be.v suitably treated forqhardening the wear: surfaces. Such way elements 5 are customarily attached to the :machine \bed hbypmeansiof screws which maybe inserted downwardlyzthroughlholesi' in the way elements andthreadedzinto.the. uns, derlying part of the;machine;b.ed. or,- .alterna;-. tively, may pass upwardly either perpendicularly or at an angle tothe way relement 'andthread into the underside oftheelementsa Asthe latter mode of attachment does not "interrupt the conto tinuity of thewaysurfaces it is.usua11ywpreferred despite the tact-that theemachine rbed. mustibet inverted or at leastturned; over on .one; sidee-or: end to afford access for;the;insertion of the; screws.

Application 1 of the above. type. of; way; cont-U struction to large heavy duty; machine-stools has; met with little successa Usuallyw access ;to;;thei interior of the bed for insertiomofuthe: screwsqiss diificult or impossibleyandzthe bedstructureseare too large to permit them to be sturnedr'over for; that purpose. Moreover; as'p'thejbeds'structure .of: such machines must bezpreciselygleveled and an: ohoredlin place whenzinstalled, removal of worn; Way elements, for refinishing'xis; utterlypimprace tical.

The primaryobjectof theinventiomis tOOVEIs come the aboVedifiicuIties andprovide way .e1e.-. -1 ments adapted to bepkeyed to. the machine-flame; structure in a manner which .enablesthemto be; quickly and easily assembled 1'therewithuinzaccue. rately located positionsa and: secured; in; place; while the structureis in itsnormal operatingpou-e sition without requiring any specialconstructionof the structure to provide accessto uthelinterior;

elements thus avoi.ding..;uneven; .weaibof gtheiways andenabling :them;to;:retain theiraocuraoyzoverz. longiperiodszuof use;-

It :is also ,an; object .of nthednventiony to provide: a; ccnstructiongwhich enables the ;way; l ments: to; belseoured ;to:the;machine bed .closelmadjacenh thfez'pointszrat-which upwardlyflirected forces are imposedaion the :ways,.; either :throueh zvt en rquer exerted 110m thetsupportedw reciprocating part by;

thenaotion oiarotarytool onzthework pathroueh ing the ,way element separated from the machine ing machines; It will; be understood,; of :course For purposes "of illustration, itherimproved way construction has beenshown inconnection with 1 a. horizontal ,machine; bed of the type used in heavy; duty horizontalboring, drilling; andmillthat the improvedtway construction can be used A with {other-types of machine tool beds or frame. structures, aswell. as twithimachine tool tables,z saddles, columns and other structures which are:

required. to su port a; reciprocatory; part, Ac-

thereof. In theattainment ofxjthis:obiect,".the

improved construction additionally presentsgthe; advantages of permitting removal ofythejmwaygv strips for reconditioning without disassemblyi oftg the machine and, what 1510f primeglimportance, without disturbing the :setup of ptheimachineahedi; orway carrying tructure;

An ancillary object is to provide a way: con struction which: imposes substantially; norqlocal-gfl: ized stresses on the machine-structuretoritheo ways cordingly; it isnotiintendedathatthis exemplary. embodiment should limituthe; inv tio w hmr e 1 spect to its ap licat on. butxit isin nded kcoy rt: thewapplication of the yimproyed wayw co structipn pf; allgtypes ofrzvmachine tool structures. and;

l kewise to cover 1i uch.;.m0difica1tions and: alter: nativeaconstructionszas.zfalllwithin the.;spirit and: scope? of; thegcinvention definedzby; the 1 ap: t

0 pended claims-.4

Referring now to; the 1 drawing; the: improved, waymconstructionahas been shown-in conjunction with axmachineetool frame; structure in: theiform 1 of f a'bed; 5 isupportingta saddleifi for translation inaas horizontal a planer The particular; saddles 3 shown supports a machine table I for translation crosswise of the bed.

The machine bed 5, as herein shown, is a rigid boxlike structure having spaced side walls I terminating at their lower ends in mounting flanges H which support the bed on its foundation and by which it may be anchored in place. The side walls [0 are connected at their upper ends by a heavy transverse member 52 formed with a depending or depressed generally convex central portion l3 disposed longitudinally of the machine bed and serving, in this instance, to collect chips produced in machining operations. Such beds are usually provided with transverse stiffening ribs and internal reinforcing elements which it is not considered necessary to show in the present case.

For supporting and guiding the saddle 8, the bed 5 is provided on its upper face with spaced parallel ways defined by a series of way elements l5. These elements, which may be alike, are constructed separately from the bed and are rigidly secured thereto in accurately located positions. Each way element has at least one side finished to provide a way surface and another side formed with an outwardly opening channelshaped groove or keyway i6 bordered on opposite sides by flat locating and supporting surfaces H. In the exemplary machine, the way element [5 is shaped to present four way surfaces, that is, it is 'formed with a fiat top surface l8 for supporting the saddle 6 and flat side surfaces 19 and 2B disposed at right angles to the top for guiding the saddle in its traverse movements. It will be understood that the Way surfaces may be of the V-type or other suitable shape if desired. One side edge of the way element l5, preferably the outer edge, is undercut to define a way surface 2| opposed to the way surface l8 and engageable by an underlying guide strip or gib 22 on the saddle. This way surface acts to resist upwardly directed forces such as those imposed thereon by the torque developed by a rotary tool acting on a workpiece.

The upper face of the machine bed 5 is shaped for cooperation with the way elements l5 to provide a strong and rigid connection and to key the elements to the bed so as to facilitate accurate location of the elements and to simplify assembly. For this purpose the bed is formed along each edge with an upstanding rib or key 25 complementally shaped with respect to the keyways I6 in the elements. As herein shown, the key 25 is formed integrally with the flat marginal edge portion 26 of the transverse member [2. Preferably the keyways l6 and keys 25 are rectangular in cross section, the keyways having accurately finished side walls 21 and 28 coasting with the similarly finished side walls 29 and 30 on the key. The respective pairs of walls are spaced apart so as to provide a tight machine fit and are precisely located in the machiningof the parts so as to position the way elements accurately upon the bed in the assembly operation.

As Will be seen by-reference to Fig. 3 of the drawing, the keyway I6 in each way element [5 is somewhat deeper than the height of the key 25, thus affording a slight clearance between the opposed surfaces of the parts after assembly. The locating and supporting surfaces ll of the elements are therefore enabled to engage and rest on supporting surfaces 3| formed on the bed at opposite sides of the key 25. Support for the way element is thus provided independently of the key 25 which serves as a means for locating the way elements and provides for their convenient attachment to the bed.

The mode of attachment of the way elements l5 to the bed 5 is an important feature of the invention since it enables the elements to be installed or removed without requiring the machine bed to be turned over or without necessitating any special construction of the bed to provide access to the interior thereof. For this purpose attachment of the ways is effected by means of drive pins 32 inserted through alined holes 33 in the depending side portions of the way elements and registering with transverse holes 34 in the keys 25. Preferably the holes 33 are drilled in the way elements before they are hardened and ground. The holes 34, on the other hand, may be drilled and reamed to size after the way elements are assembled with the machine bed and while the elements are held in place by suitable clamps. Accurate registration of the holes is thus insured and no unnecessary strains are imposed on the bed and way elements or the pins when the machine is assembled.

In the exemplary machine, the pins 32 are cylindrical in form and the holes 33 and 34are dimensioned to receive them with a driving fit. It will be understood, of course, that pins of other shapes, as for example tapered pins, may be used if desired. As the pins are tightly fitted in any case, they have no tendency to work loose due to vibration of the machine and are therefore more dependable than screws.

While the improved way construction is particularly well adapted for machine bed-s of the type above described, it may be utilized to advantage in other machine tool frame structures and in other parts of a machine tool required to support reciprocatory tables, heads or other elements. Fig. 1 of the drawings illustrates another such application, that is, it shows the saddle 6 provided with ways constructed in accordance with the invention. For this purpose the upper face of the saddle 6 is formed with upstanding keys 35 adapted to cooperate with keyways in the way elements 36. These elements may be similar to elements l5 heretofore described. The application of the improved way construction to columns, tables and other machine parts will be readily apparent.

, The facility with which way elements may be manufactured and assembled with the frame or bed of the machine with this improved construction will be readily appreciated. The way elements [5 can be made in lengths short enough to machine with conventional machine tools and all operations, including hardening and final precision grinding can be completed before assembly. This is for the reason that the way surfaces l82l are accurately coordinated with the supporting surfaces I! which cooperate with the surfaces 3| of the machine bed to support and accurately determine the vertical position of the ways. Similarly, the accurately formed surfaces 2'!-30 of the keyways l6 and the keys 25 cooperate in locating the way elements in a transverse direction. With this arrangement no grinding or other finishing operations are required after the way elements are secured in place.

The securing of the way elements to the machine frame is a quick and easy operation. After the holes 34 have been drilled through the keys 25 in the initial assembly of the machine, it is only necessary to place the way elements over the keys, insert the pins 34 and drive them home. The pins are easilyaccessible for insertion or removal while ,the .machineframe is .in

its normal position, thus makingit,.,unnecessary,

to turn the structure over or for a workman to crawl insides This is :particularly;advantageous when the way elements require refinishing as they can. be removed and reinstalled individually with-out disassembling the'machine.

Normal loads imposedonthe ways are .trans-; mitted to the machine'bed through the support-: ing surfaces ll and 3 l and are 'therefore'unn formly distributed. The pins 32 and keys 25 are subject only to relatively small stresses such as those resulting from the torque produced by a rotary tool. The location of the pins closely adjacent the way surface 2| which takes such thrust serves to minimize the stresses and enables the way elements to resist them without objectionable distortion.

I claim as my invention:

1. In a machine tool having a rigid frame structure, the combination of ways on said frame structure for supporting and guiding a translatable part, said ways comprising way elements machined to finished dimensions and hardened separately from said structure and removably secured thereto, each of said way elements comprising an elongated member having at least one side finished to provide a way surface and another side formed with a longitudinal keyway, said frame structure being formed with upstanding keys dimensioned for reception in the keyways of said way elements, said keyways and said keys being bordered on opposite sides with complemental supporting surfaces adapted to interengage to transmit the load on the ways directly to said frame structure, and drive pins inserted through transversely disposed holes in said way elements and said keys for retaining the elements in assembled relation with the frame structure, said holes being located so as to provide access to said pins for insertion or removal while the frame structure is in its normal operative position.

2. In a machine tool, in combination, a rigid frame structure, spaced parallel ways on said structure for supporting and guiding a translatable machine part, said ways comprising elongated way elements adapted to be machined to finished form and hardened separately from said frame structure and to be removably secured thereto, each of said way elements having way surfaces formed on a plurality of its sides and a longitudinal keyway formed in another side, said other side being finished to provide locating surfaces on opposite sides of said keyway accurately located with respect to said way surfaces, said frame structure having a pair of upstanding longitudinally disposed keys dimensioned to fit in the keyways of said elements with a tight fit, locating surfaces formed on the frame structure on opposite sides of said keys for coaction with the locating surfaces on said elements, said keyways having a depth greater than the height of said keys so as to permit engagement of said locating surfaces for accurate positioning of the way surfaces with respect to the frame structure, and transverse drive pins inserted through registering holes in the way elements and said keys for retaining the elements in assembled relation with the frame structure.

3. In a machine tool having a rigid frame structure, the combination of spaced parallel Ways on said structure for supporting and guiding a translatable part, said ways comprising way e1edimensioned forreceptionxin the keyways of said way elements, .saidikeyways and said keys being bordered onzopp'osite sidesby complemental locat ing.surfacescadaptedito interengage to locate the Way surfaces with respect to the structure and to transmit the load on the ways directly to the frame structure, said keyways having a depth effective to afford clearance with the top of said keys when said supporting surfaces are engaged, and removable drive pins extending transversely through said way elements and said keys for retaining the elements in assembled relation with the frame structure.

4. In a machine tool, in combination, a rigid frame structure, spaced parallel ways on said structure for supporting and guiding a translatable machine part, said ways comprising elongated way elements adapted to be machined to finished form and hardened separately from said frame structure and to be removably secured thereto,

each of said way elements having a way surface,

formed on one side and an opposed way surface formed on an undercut portion of the opposite side, said opposite side having a longitudinal keyway formed therein and being finished to provide flat surfaces on opposite sides of the keyway accurately located with respect to said way surfaces, upstanding keys formed on and integral with said frame structure, said keys being dimensioned for reception in the keyways of said elements with a tight fit, fiat locating surfaces formed on the frame structure on opposite sides of said keys for coaction with the locating surfaces on said elements, said keyways having a depth such as to provide clearance over the tops of the keys and thus permit engagement of said locating surfaces for positioning the way surfaces with respect to the frame structure and for transferring the load on the ways directly to the frame structure, and drive pins inserted through transversely disposed registering holes in the way elements and the keys for retaining the elements in assembled relation with the frame structure, said pins being located closely adjacent the way surface on said opposite side of the way element and effective to resist deformation of the element by forces exerted on such surface.

5. In a machine tool, in combination, a rigid frame structure, spaced parallel ways on said structure for supporting and guiding a translatable machine part, said ways comprising elongated way elements adapted to be machined to finished form and hardened separately from said frame structure and to be removably secured thereto, each of said way elements having way surfaces formed on two sides and having an inner face engageable with the adjacent face of said frame structure, one of said faces being formed to present a longitudinal key structure with fiat surfaces disposed at opposite sides thereof and facing in the same direction as the key, the other of said faces being shaped to present a longitudinal keyway dimensioned to receive said key with a tight fit and having flat locating surfaces at opposite sides facing in the same direction as the keyway, said keyway having a depth such as to provide clearance between the top of the key and 7 the bottom of the keyway so as to permit engage- REFERENCES CITED ment of the flat surfaces of the two faces for The following references are of record in the positioning the way surface with respect to the 1 hi t frame structure and for transferring the load on fi e of t S the ways directly to the frame structure, and 5 NI ED TATES PATENTS thread free pins adapted to be driven through transversely disposed registering holes in the keys gggg j i' Aup gog and the adjacent walls of the keyway for retein- 1 901522 Meier M51 14 1933 mg the way elements in assembled r lati with 1951514 Lovel r 01934 the frame structure without imposi excessive 10 1 5 gg Apl 2' 1940 localized stresses on the way elements.

WILLIAM E. RUTZ.

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