US2320776A - Machine tool - Google Patents

Description

June 1, 1943. N 2,320,776 MACHINE TOOL Filed May 16, 1941 Patented June 1, 1943 MACHINE TOOL George Gorton, Racine, Wis., assignor to George Gorton Machine 00., Racine, Wis., a corporation of Wisconsin Application May 16, 1941, Serial No. 393,811

Claims. (CI. 90-11) This invention relates to machine tools; and the objects and nature of the invention will be apparent to those skilled in the art in the light of the following explanations of the accompanying drawing disclosures of a preferred mechanother means to operate on the work, and that is rendered longitudinally slidable or adjustable with respect to the support, means being provided whereby the ram can be released for relative adjustment and whereby the ram can be rigidly locked in the position to which adjusted, and A whereby the ram is rendered removable and replaceable with respect to the support.

For example, the invention, more particularly,

relates to machines of the general type disclosed by my Patent No. 1,862,052, issued June 7, 1932, 1

without intending to so limit all features of my invention.

An object of the invention is to provide improved means for rigidly locking an adjustable,

removable ram of so-called box-like construction having a closed or rigid bottom floor or wall, to

its complementary supporting column or other base, and, preferably, but not necessarily in all instances, to render such ram applicable to and removable from such column or other support and slidably adjustable with respect thereto.

And a further object of the invention is to so improve the locking and releasable dovetail slidable operative connection between the removable ram and the complementary portion of the' column or other support, as to gain increased rigidity of the ram against relative movements when looked, as well as increased structural strength and ease of operation, and to gain increased accuracy tolerance between the complementary dovetail portions and thus reduce machine production costs by reducing accurate close fit requirements between the dovetail portions, and also to permit successful application of selected replaceable rams to and locking and release from the complementary dovetail portion of the column or other support, where the dovetail por- .tions of such replaceable rams differ slightly in cross sectional dimensions from each other and from said column complementary dovetail portion. 7

With the foregoing and other objects in view,- brought out by the following description, my invention consists, in certain novel function-performing features, structures and combinations as more fully hereinafterexplained and-specified, whether or not the ram is removable and/or replaceable. I 7

Referring to the accompanying drawing forming a part hereof;

Fig. 1 shows in side elevation, the upper portion of an example machine tool that includes one fro-m among other example embodiments of the instant invention; the remaining portions of the machine tool base frame and column and the knee and work table and adjusting means, are for example, disclosed broadly by my hereinbefore identified patent.

Fig. 2 shows in rear elevation, the structure disclosed by Fig. 1. I i

Fig. 3 is a detail sectional perspective, illustrating in part the ram, the upper or deck portion of the column or other support, and the' double-wedge clamping bar or movable section of the tenon or male dovetail portion, with such parts shown in abnormal separated positions.

Fig. 4 is a broken detail perspective of the movable clamping tenon or male section of the dovetail connection.

Merely for purposes of explanation of an example embodiment of theinvention and itsapplication, the drawing illustrates a type of machine tool from among others, to which the invention is adaptable, and reference is made to my above identified patent for illustration of the portions of an example machine tool, not disclosed by the instant drawing.

The problem solved by the instant invention concerns those machine tools and the like, wherein a cutter-head-carrying ram or elongated slide is operatively coupled to a usually rigid part of the machine frame,.by a'dovetail connection, and

the invention more particularly involves improvements in the structure and organization of such dovetail connection, to gain substantially maximum rigidity and other advantages more particularly pointed out hereinafter.

Referring to the example machine tool, illustrated by the accompanying drawing, the rigid usually hollow upstanding column is usually rigid with or forms part of the machine base or frame, and at its upper end receives the elongated ram or slide 2, that usually extends horizontally from rear to front across the upper end of said support or column I, with its front end usually extending forwardly beyond the column to overhang the work table.

The function of the ram 2, is to carry the cutter head 3, and hold the same at the required position overhanging the work on the Work table.

The cutter head 3, can, if so desired, be located in front of the ram and mounted to the forwardly projecting front end thereof.

This cutter head can be of any suitable structure and organization, and usually provides a suitable driven rotary spindle 5, driving any suitable cutter 5, to operate on the work on the work holder or table. If so desired, the cutter head or the ram can carry a motor 6, for driving said spindle through the medium of any suitable power transmission. The cutter head can be of the type of the vertical spindle milling disclosed by the hereinbefore identified patent, or can be of the universally adjustable type to present the driven cutter spindle at various angular positions, or of any other type adaptable to the sliding ram organization.

The top wall I, of the column I, and the cross floor or bottom wall 8, of the ram 2, provide the complementary longitudinal tenon or male and female or mortise portions of a dovetail operative connection holding the ram down on the column for longitudinal sliding adjustment, and for locking the ram against relative movements or looseness in the position to which adjusted.

In the example illustrated, the slidable elongated ram 2, is of rigid stiff preferably, hollow box-like construction with its rigid bottom floor or cross wall 8, rigidly connecting its vertical side walls and extending, preferably unbroken, longitudinally throughout the front to rear length of the ram. In this example, the undercut or female portion 9, of the dovetail connection is provided at the under side of the ram floor. This under-cut groove or slideway 9, ex-

tends approximately centrally throughout the length of the ram floor and opens through the front and rear ends of the ram, and is open at the bottom of the ram throughout its length, between the lower parallel longitudinal laterallyspaced edges of the opposite-side parallel upwardly and outwardly inclined edge walls ID, that meet the longitudinal horizontal top surface II, of the groove 9, formed by floor 8, of the ram,

The bottom of the ram 2, provides longitudinal parallel flat supporting runners or slide surfaces I2, between which the groove 9, is located. These surfacesI2, are in a common horizontal plane and extend throughout the front to rear length of the runner.

The cross wall 1, throughout the length of the front to rear top of the column I, forms a rigid horizontal elongated supporting deck and slideway for the ram 2. The top surface of this deck provides laterally-spaced parallel opposite side flat smooth longitudinal slide surfaces in a common longitudinal horizontal plane, to receive the slide surfaces I2, of the runners of the ram. These slide rails or surfaces I3, of the column deck extend throughout the length of the column deck.

The portion of the dovetail connection between the ram and column, that connects the Thus, where the dovetail groove, such as 9, is'

located in the ram, the complementary tenon or male portion of the dovetail and the clamping means are located on the column.

According to my invention, the male portion of the dovetail, that is complementary to the female portion, for example, groove 9, is made up of two longitudinal partial sections, one partial section i4, being rigid with the column deck I, with the other and complementary longitudinal partial section, consisting of a separate stiff normally-non-fiexible longitudinal double- Wedge-forming clamping bar I5, provided with clamping and releasing means.

By reference to Figs. 2 and 3, it will be noted that the fixed male or tencn section Id, of the dovetail, is-integral or rigid with the column deck, and occupies only a fraction or portion of the transverse width of the groove 9, say, only about one-half, more or less, of the transverse dimensions of the groove, while the remaining width of said groove is occupied by the separate section of said male portion; namely, the separate clamping bar I5, and that when the two sections I4, I5, are brought operatively together they are complementary to and operatively'fill the groove, and provide the necessary inclined longitudinal edges to cooperate with the inclined groove edge walls III, ID, to lock the ram to the column deck.

Referring to Fig. 3; the male section or portion I4, rigid or integral with the eolumn deck forms the right section of the full width male portion required, and this partial portion I4, at its upstanding right hand longitudinal edge provides the upwardly and outwardly inclined longitudinal wall I6, that-is complementary to and overhangs and fits the right hand downwardly and inwardly inclined longitudinal edge It}, of groove 9.

to the right hand inclined edge surface of groove 9.

The separate movable partial male portion composed of the stiff clamping bar I5, provides a downwardly and inwardly inclined longitudinal edge wall I9, that is complementary to and parallel with the left hand inclined longitudinal edge wall H, of the rigid partial male section I4, referring to Fig. 3.

The opposite left hand longitudinal inclined edge wall I8, (Fig. 3) is complementary to and parallel with the left hand longitudinal inclined edge'wall ID, of groove 9. V

The clampingbar- I5, is thus of double Wedge formation in end elevation as its edge flat'walls I8, I9, extending throughout the length of the bar, are both inclineddownwardly and inwardly from the substantially'flat top face of the bar to the substantially flat relatively narrow bottom faceof the bar.

'15 of substantial width and thickness to render the same stiff and substantially-rigid against ob- *jectiona-ble flexible or bending under-- clamping and other transverse and vertical stresses and strains. When the parts making up the dovetail connection between the ram and column deck, are operatively assembled (Fig. 2) with the ram runners I2, resting on the column rails I3, and the right hand longitudinal edge wall I9 (Fig. 3) of the ram closely fitting the longitudinal edge wall I6, of rigid male portion It, the clamping bar I5, snugly fills in the gap between the longitudinal left hand edge wall ID, of the ram and the longitudinal edge wall [1, of the rigid male portion I4, with the longitudinal edge walls I8, I9, of bar I 5, closing down on the complementary longitudinal edge walls I 0, and ll, of the ram and portion I4, respectively, with down clamping and laterally expanding pressure. The bar I5, when locked in operative clamping position, is firmly held against lateral or endwise relative movements and against normal vertical movements by suitable clamping and releasing means. For example, I show the bar I5, provided with several stiff or rigid parallel depending studs or rods 29, preferably longitudinally screw threaded at least at their lower portions. These studs are at their upper ends rigidly secured to the bar I5, preferably, at spaced intervals remote from the bar ends and preferably, along the longitudinal axis of the bar, preferably, without forming projecting portions at the top surface of the bar.

The top deck I, of the column I, is formed with vertical holes or bores 2|, for the passage of the depending studs 20, with these holes extending down through exposed transverse por- 'tions of the column to form abutments for accessible nuts 22, screwed on the downwardly pro- -jecting screw threaded ends of the studs, whereby the clamping bar I5, can be drawn down and held in rigid clamping position, or can be loosened to the slight extent necessary to permit the ram to be pushed or propelled in either direction on the column deck by hand or otherwise, to bring the cutter means in the desired position with respect to the work. When the ram has been moved to the desired position, it can be easily and quickly rigidly clamped to the column deck by manipulation of the accessible nuts 22. The vertical thickness of the clamping bar I5,, may approximate the vertical thickness of the rigid partial portion I4, above the horizontal plane of the rail surfaces I3, although my invention is not so restricted. However, when the bar is in rigidly held clamping position, clearance is provided between the top surface of the bar I5, and the top wall surface II, of the female groove '9, and preferably between the relatively narrow bottom surface of said bar and the top surface of the column deck between the rigid maleportion I4, and the adjacent rail I3, see slight longitudinal depression 23, Fig. 3.

. The one piece or single elongated clamping bar I5, of substantial width and thickness, extends substantially throughout the front to rear length of the column deck, i. e. throughout the length of .1 the dovetail rigid portion I4. This clamping bar I5, when in operative clamping position, is held against relative lateral movements by the stiff bars or studs 20, vertically slidable in the frame,

. and requires but slight bodily vertical movements :for rigidly clamping theram and for releasing .the ram, for sliding adjustment, by reason of the fact that the bar forms a double wedge with its upwardly'and outwardly flaring smooth inclined ,opposite longitudinal edge walls always overhanging and contacting the correspondingly up-' wardly and outwardly flaring smooth inclined longitudinal complementary edge Walls I1, and I0. Thus, by manipulation of the nuts 22, the clamping bar I5, can be quickly pulled down to rigidly lock the ram down on the column deck, and by slight loosening of said nuts, said bar can be loosened .to the extent necessary to permit sliding adjustment of the rain. The bar I5, when being drawn down, performs a double lateral wedging action, both on inclined edge I0 (Fig. 3) to force the right hand inclined edge I0, (Fig. 3) tightly against inclined edge I6, of rigid part I 4, while the inclined edges I8, I9, of said bar tightly close down on inclined edges I1, and adjacent III, to rigidly lock the ram down on the column deck against relative movements.

This simple and effective organization is of particular advantage in machines doing heavy duty where the cutter spindles must be accurately maintained against relative lateral movements, and where the rams are adjusted to advanced forward positions on the columns or supports.

In many machines of this general character, the rams are detachable from and applicable to the columns, which in my instant embodiment is rendered possible by loosening the clamping bar t5, and sliding the'ram forwardly on the column free from the dovetail connection.

As different rams are removable and replaceable, on the one column, advantages are gained where my invention is employed, because of its capacity to receive and look different rams that vary within limits in the transversedimensions of their female grooves 9. This is possible because the bodily vertically movable double wedge clamping bar I5, of substantial width, cooperating with rigid male section I4, and the adjacent inclined edge wall I 9, of the ram, functions to take up variations in the transverse Width of the grooves 9, of different rams, by reason of the ample clearance provided at both the top and bottom of bar I5, to permit an extended range of vertical movements of said bar with the inclined edges I8, I9, contacting only the inclined edges I1, and the adjacent inclined edge I0. This fact extends the range of accuracy tolerance and reduces the need for extreme accuracy in certain dovetail surfaces and dimensions heretofore believed to be necessary.

The clamping bar l5, during a ram locking or clamping operation, will move down to final clamping position wherein the bar fully and fixedly fills the transverse space from rigid edge wall 11, to the adjacent edge wall I 0, of the ram groove I0. Where the transverse distance between'rigid wall I1, and wall II], of a particular ram, is normal or comparatively short, the downward movement of the bar I5, to final clamping position will be relatively short. When another ram is substituted, on the column deck, its groove 9, may be over wide, making the distance from fixed edge wallv ll, totheadjacent edge Wall I9, of groove 9, overlong. In such event, the wedge and clamping bar I5, will move 7 down a greater distance, than where' the ram grOOVe 9, is not so wide, before it reaches the final rigid clamping position wherein said bar rigidly of grooves 9, of different rams where used at differenttimes on the same column deck and its male dovetail portion, i increased by so mounting the bar as. to render the same bodily shiftable laterally, within limits, when'loosened; and'notsin clamped locking position. T

When the=bar isthus loose, it is' free within him its, to shift: laterallyvvhile being. drawn-dowmto clamping position, to centert itself betweentthe rigid wall I], andithe iadjacentgrooveedge wall It, to properly perform itsqlateralwedging and down clamping functions, particularlyvwhere the variations in ram. grooves '9',.==are:near.the; maxi.-

mum permitted.

However, the bar mounting and clamping means are such thatthebar is rigidly held against relative lateral looseness'when locked clamping position.

The desired limited lateral .looseness of :thegbazr I5, when not. in clamped: position, where the :bar is provided with the rigid depending studs 20; is in the example embodiment disclosed, provided for by the relatively enlarged internal cross 'dirnensions of the vertical slideways or holes 21;;witl1 respect to the cross dimensions of the. studs-2B, that are slidably confinedin-said holes. ;'Ihe desired limited lateral looseness of vthe bar, when notfixedly clamped by nuts; 22,and stud 20, is thus attained.

The bar, when loose, can within limits thus bodily slide laterally, duringthe clamping operation, to adapt and center itself on the edge walls different grooves 9.

Thus, in the disclosed embodiment oimy invention, it is not essential to accuratelys-crape and .finish the inclined edge wall ll, of the rigid-portion H, th inclined edge walls |8, Iii, of the clamping bar, and the left hand inclined ed e wall 18, (Fig. 3) as smooth planin is sufficient.

It is desirable to scrape and accurately finish-the slide surfaces l2, l2, and the rail surfaces; 13,13, and the surfaces of the inclined edge wall; 110, and its complementary, inclined edge wall it.

The disclosure hereof is 'ior purposes of explanation of an example embodiment of the;invention, and not for purposes of limitation except .where so required by the prior art.

What I claim:

- -1. In amachine tool of the typehavinga znormally-fixedly-clamped ram member removably and longitudinally-slidably confinedlto a supporting deck member by a longitudinalidovetail'con- .nection; said dovetail connection comprising a ifemale open-end groove extending: longitudinally of one of said members and having. opposite-side 1 parallel wedging edgewallspthe othermernber provided with 'thelongitudinalmale tenon extending through said groove and having opposite side parallel wedging .edge walls complementary :to and transversely overlapping the edge wallsof the said groove, said male tGHOIIliIICIUdiDQuaGOU- ble wedge longitudinal relatively laterally and and from ram clampingrand' releasing positions.

2. A machine tool comprising a supporting deck member; a ram member slidable .on saiddeck member; one of said members providingithe .female groove of a dovetail longitudinally-slidable connection between said members ':the;other r. member pr vi n the maletenon;arransedilon-175 in theiwidths of gitudinally. in said groove, said groove and said tenon at their opposite longitudinal sideshaving complementaryparallelslidably.contactingtransverselyeoverlapping wedging .edge .walls; said tenon. including afixedi'longitudinal: partial-width tenon providing one .of the aforesaid: wedging edge. wallsof the tenonan'd; also; providingasecond' fixedlongitudinal parallel edge wallilocate'd intermediatexthe overall width of saidtenon and a longitudinal clamping bar insaidgroovebetween said: second edge walli oflexsaid'fixedtenon portion and the adjacent transversawedgingedge wall of said groove, said bar having a longitudinal wedging edge for laterallyiwedging contact. with said adjacent edge wall of: the groove, and another longitudinal wedgingisurface-for laterally wedge ing contact with said secondedge "wall-oi said fixed tenonportion; saidbar having an extended range of-relative vertical movementstoward-ram clamping positions; :said bar, while being propelled toward. ram locking positions, being relatively-bodily. laterally movable .toward'theia'djacent groove edge wall .under'thelateraliwedging action of said second edge wall of saidfixed tenon; an'dimeansfor propelling said bar through its, extended clampingmovementsand. for releasably locking the'same in ram .clampingpositions.

3.In a machine having a normally rigidly clamped ram 1member longitudinally adjustable on a supporting deck member, one of. said members having the female groove ofta. dovetail con- ;nection, and the other-member having the complementary :male tenon extending through said groove, with the tenon and groove having opposite side complementary longitudinal laterally lwedging, slide surfaces; the provision of mechaanismrfor releasably clamping the ram membento the deck member, said. mechanism including an elongated stiff: clamping bar arranged 'longitudh :nally through saidfemale groove and. havingsa longitudinal transversely wedgingsurface complementary toand overlapping one of said-longitudinal side'surfaces of said groove, saidbar also having ;,a second longitudinal transversely wedging-surface, spaced'laterally from its. said: first named surface and overlapping and complementarytoa; longitudinal laterally wedgingfixed surface of saidtenon; and means for relatively moving said bar vertically on itsram .clampingmovemer ts and-for releasably locking thexbar inlts .rarn clamping positions, said means rendering said .bar laterally movable for. self centeringiwithinsaid groove between said'gro'ove side surface and said'fixed tenon surface, .duringbarmovemel'its toward ram clamping positions.

4, Ina machine of the type having a normally fixedly-clamped ram member longitudinally slidable on a supporting ,deck memberifor adjustment and confined toathe deck by: a dovetail connection, the female groove of said connection being provided by one 101" said members and the longitudinal-male ftenon by. the/other member, said groove and tenon. having .oppositesidelongitudinal overlapping lateral. vvedging surfaces; the iplfovisionof a, tenon capabletof' expanding vin width to transversely. occupy; .a, slightly wider or narrowerfemale groove, :said tenon. on onellongidinal surface and the adjacent longitudinal internal side surface of said groove, said clamping bar having longitudinal lateral wedging surfaces complementary to said intermediate and adjacent groove side surfaces respectively, said bar being relatively vertically movable and laterally self centering; screw threaded operating means for drawing said bar vertically to and for releasably maintaining the same in ram locking positions, said operating means comprising a rotary threaded nut, the member carrying said tenon providing an abutment for said nut.

5. A machine tool havin a supporting deck provided with vertical guide means and a part providing transverse abutment means; a normally-fixedly clamped ram longitudinally slidable on said deck; said deck having a longitudinal male tenon portion; said ram providing a female longitudinal groove receiving and longitudinally slidable on said tenon, said groove having longitudinal downwardly converging opposite edge surfaces, said tenon providing complementary longitudinal upwardly diverging opposite edge surfaces, and a longitudinal elongated clamping bar providing one of the longitudinal upwardly diverging edge surfaces of said tenon, and constituting a cooperative partial-width longitudinal portion of said tenon, said bar being relatively vertically movable to and from ram clamping positions, and provided with pull-down means fixed thereto and loosely laterally confined by said guide means; and stop means having elongated screw-threaded connection with said pull-down means, and operatively cooperating with said abutment means.

GEORGE GORTON.

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