US2514146A - Tool for cutoff and threading operations and the like - Google Patents

Description

TOOL FOR CUTOFF AND THREADING GPERATIONS AND THE LIKE Filed April 25, 1947 2 2 i I 4 E [a 1 if 44 E- 7M JVZ'ZZZ'M E5? Jd/z 70 I Q BY 71 Fig.5.

ifTdIAE/i Patented July 4, 1950 mcc v TOOL FOR CUTOFF AND-HTHRHEADING OPERATIONS AND;THE LIKE,

William A. St. Jei iil, Detroit; Mich. Application April 25, 1947,. Serial No..743,858

4 Claims.

The present invention relates to machine tools, and particularly to an improved tool construction especially designed for lathes and adapted to improve the performance of the lathe in cut-off operations and in the performance of such oper ations as grooving and threading, wherein difliculty is frequently encountered due to the tendency of the work to climb over the top of the tool, particularly where the work has considerable unsupported length in relation to its diameter. On account of this tendency, chatter and binding are frequently encountered in the use of cut-off tools of the varieties commonly used at the present time, and it is also often necessary to take a shallower cut or to use a lower rate of cross feed than would otherwise be feasible.

It has heretofore been proposed to use a tool steadying device consisting ofan arm adapted to overlie and to bear against the top of the rotating workpiece to prevent the workpiece from rising, and so to eliminate the objectionable tendencies previously mentioned. 7

Metal working lathes are quite universally constructed with a cross slide which travels in a horizontal plane, but the vertical distance between the top of the cross slide and the axis of the spindle varies in lathes of different manufacture as well as between lathes of different sizes. It is desirable also to vary the vertical position of the point of engagementbetween the cutting edge of the tool and the work, when cutting different types of material. For example, in performing a cut-off or similar operation upon a material such as brass, it is common to set the cutting edge to engage the work somewhat below the axis of rotation, while in cutting certain other types of materials, it is more usual to place the cutting edge somewhat above the axis. In order to permit standard types of cutting tools to be used under these varying conditions, and upon lathes wherein the vertical distance between the top of the cross slide and the axis of the spindle varies, lathes are commonly provided with a rocker structure or equivalent means whereby the cutting tool may be rocked about a longitudinal axis to permit the cutting edge of a tool carried thereby to be raised or lowered. It has been found that steadying devices of the types known to the prior art are unsatisfactory under many of the operating conditions encountered in the performance of the above-indicated operations, and frequent breakage of either the steadying device or the tool re-,

' mitting the work to tend to ride over the point of the tool. H

It is animportant object of the present invention to eliminate the above-noted difliculties, and to provide a steadying device which permits the tool to be fed into the work in a tilted position and with the point of the tool either above or below the spindle axis, if desired, without thereby unduly stressing either the tool, the work, orthe 1p; steadying structure. ,An object related to that last stated is toprovidean improved steadying device of the indicated character having a tiltable steadying shoe rock able about an axis transverse to the shoe and adapted to be set in a true horizontal position, or positioned parallel to'the cross feed path, without regardto'the angular'ity of the cutting tool, the arrangementbeing such that the shoe may be set in an approximate manner, merelyby eye, and may then be adjusted by the mechanic duringthe performance of the cutting operation, the adjust mentbeing effectedsimply by the feel of the parts during operation, so that accurate gaging or. elaborate set-up methods are not required, de-' spite which the above-noted difficulties and the frequent breakage of such devices constructed in accordance with prior known designs are eliminated.

Another object of the invention is to provide an" improved tool holder of the character indicated incorporating novel, simplified and extremely rug ged means for supporting the cut-off blade and the stea'dying shoe means.

Still another object is to incorporate in a device of the character indicated, improved means for adjustingthe position of the steadying shoe means longitudinally with respect to the work, which adjusting means permits the shoe to be arranged either perpendicularly with respect to the axis ofv rotation of the work or at any desired angle within limits of adjustment, whereby the position of the steadying shoe means may be altered to .accommodate it to the configuration of the work and to permit the cut-off blade or other tool to operate close to a shoulder or other configuration without interference.

' Other objects and advantages will be apparent upon consideration of the present disclosure in its entirety. J V In the drawings: Fig. 1 is a side elevational view of a tool-holding structure incorporating the principles of the pres ent invention, corresponding to a transverse section through a portion of a lathe upon which the 55 inventive structure is depicted as installed, the

work being illustrated in cross section and the cross slide of the lathe shown in side elevation;

Fig. 2 is a partial top plan view;

Figs. 3, 4 and are sectional views taken substantially on the lines 33, 4-4, and 55, respectively, of Fig. 1 and looking in the direction of the arrows;

Fig. 6 is. a perspective view of the shoe-supporting arm; and

Fig. '7 is a perspective view of the arm-supporting collar.

Referring now to the drawings, reference character l9 designates generally the. cross slide of a lathe, which is not otherwise illustrated, since as will be appreciated, the details of construction of the lathe or other machine tool upon which the invention is employedform no. part of my present invention and may be varied widely. The cross slide is adapted to be fed into and retracted from the work along the line designated lfby'suitable cross feeding means controllable by means of the hand crank l4. A tool post I5 is attached to the top" of the cross slide ill in any suitable or conventionalmanne'r as by means of the if-slot 2E! and T-head l8 engaged in the slot '20, which is'formed in the surface of the cross slide. The rocker assembly Hifl permits the tool tobe tilted about a longitudinal axis. A clamping screw 22' axially supported by and having a head portion 2 3 projecting above the post 1-5 isadapted to detachably fasten to the post a tool holder generally designated 26, the shank of which engages in a slot 25 in the post. It will be seen that the arrangement of these parts is also conventional in character and subject to variation without departure from the spirit'of the invention.

' The head portion 26 ofthe tool holder is provided with a horizontal; slot 23 formed substantially centrally thereof and. which is narrow vertically and extends entirely through the head to divide it into upper and lower sections 35, 36. A relatively shallow dovetailed tool-holdingslot 32' is formed horizontally in one perpendicular face 30' of the head, adapted to receive a tool, shown asv a conventional cut-101T blade 34. It will be seen that. the slot 32 is formed partly in each of the sections 35, 36. The vertical dimension of the slot 32 is such that the blade. 34, may be readily placed in or removed'from' the slot when the upper and lower head sections 35, 36 are in their relaxed positioning. The sections 35, 36- may be forced toward one another; to clamp the blade 34 in place, however, by means of a combined clamping screw and post member 38 having a lower clamping screw portion 44 which extends vertically through the head and which is received in aligned, bored portions 40, 42' in the upperand lower head sections respectively. Screw portion 44 extends freely through the upper bore section All, but such screw portion is threaded into suitably tapped threads formedin the lower bore section 42.

The clamping post 33' is also provided with an integral shoulder 45 overhanging the top section 35 of the head 23; while the upper portion 35 of the post is cylindrical and carries an integral squared or other suitably configured wrench-rece'iving head portion' lii. It will be seen that by virtue of this arrangement the postmay. be'turned in such direction as to force the shoulder. 45 against the top section 35 while the lower section 36 is drawn upwardly by the screw-threaded portion M, the two sectionstfi', sfiibeing thereby forced together to clamp thebladein position.

The cylindrical a clamping collar bracket 48 which is vertically split upon one side as indicated at 53, the split sections being adapted to be drawn together by a clamping screw 52 in such manner that when the screw is tightened the collar bracket 48 is rigidly held upon the post, while when the screw is loosened, the collar bracket may be moved vertically along the post for adjustment. The collar bracketsw-ingablysupportsan arm Eli-which projects horizontally therefrom, the end of the arm adjacent the collar being contoured to describe a partly cylindrical convex surface. The collar bracket E8 is provided with acorresponding partly cylindrical concaved seat 56 against which the convex end of the arm 54 seats, these parts having a common vertical axis which is the locus of a screw; ea whichpivotally connects the arm to the, collar. It will be seen that a forwardly projecting supporting portion 58 formed integrally with the collar bracket 68 projects outwardly from thelatter beyond the concaved seat portion 56 and underlies the rounded rear end 55 of the arm 5 The screw 6t, which is smooth except at its lower end which threadedly engagesbra'chet portion 58, extends through and accurately fits a drilled hole diextendi'ng axially vertically through the rounded extremity 55 ofthe arm M. The opening 64' formed in the supporting bracket portion :38 is correspondingly axially disposed with respect to the cylindrically concaved seat 55. When the screw is loosened, the arm 54 may swing easily. These parts and the seat portions 55, 5b are accurately iittedand closely engage one' another, so that the seat portions may take the load of force transmitted upwardly through the shoe and arm even when the screw is tightened to hold the arm against swinging. The arm 54 preferably tapers to decreasing width toward its outer end and is adaptedto overlie a workpiece as W mounted in the lathe.

Ashoe ill is supported by and beneath the arm 54 and may be of similar tapering configuration, viewed in plan. The shoe is preferably provided with a hardened bottom or wear plate portion 12 and is so supported that it may be tilted about a longitudinalaxis, The inner end of the shoe is provided with a pair oflaterally spaced upwardly extending pierced lug portions 7-3; 14 which extend upon opposite sides of a centrally disposed downwardly projecting tongue or lugj portion 15 carried by the arm 54 a pivot pin H5 being provided extendingthrough all of the lug portions '83, Hi, 15. An adjusting and reaction screw 18) is threaded in a suitably tapped hole 83 extending vertically through the arm Eulnear its end, the lower extremity of the screw engagingthe topof the shoe 19-. If desired, a certain amount of frictional resistance may be provided tending to oppose turning of the screw 18, as-by forming a longitudinal slot 82 extending vertically-between the; free end of; the arm 54 and" the hole f, the. split ends which are thereby de-' fined being slightly pressed together so that the screw is frictionally gripped between them yet may be easily turned by a wrench whenever desired.

The head portion 261s shown as provided with a screw 85 threaded in a suitably tapped vertical opening (undesignated) extending, through thetop section 35 of: the head, the lower extremity of the screw bearing against the upper surface of the lower section .38 of the head. Screw 85 thus limits movement of the sections 35, 36 to:- ward' one another and prevents their being portion 39 ofthe post carries 75 clamped so tightly by thescrew post 38 as to distort their relaxed positioning. It is also possibleto somewhat spread the laws by means of the screw 85 to permit the acceptance of a blade of somewhat greater vertical dimension by the slot 32, or to enable the jaws to be spread if they havebecome distorted due to carelessness as by being clamped together too tightlywith the screw 85 loosened so completely that it fails to afford the intended protection. against springing of the aws.

It is believed that the .manner of using the invention will be apparent to those skilled in the art from the foregoing description, although it may be helpful to summarize briefly the operation and some of the operative considerations involved in the design. Where the dimensions of the lathe are such that the cutting blade may be mounted in a horizontal position as shown in the drawings, with the cutting edge in horizontal alignment with the axis of rotation of the work, since post 38 is then in vertical position, the shoe is also adjusted to horizontal position by means of the screw l8, and the collar 48 is placed in a position such that the bottom of the shoe bears against the top of the work as shown in Fig. 1 when the screw 52 is tightened. The shoe is thus rigidly held in this position, and any tendency of the work to climb with respect to the cutter as the work rotates in the direction of the arrow 84 is opposed by the shoe. Force applied to the bottom of the shoe is transmitted to the arm 54 through the screw it and through lugs l4, '15, the resultant tendency to rock the arm 54 upwardly placing the bracket portion 58 in tension and the rounded seat portions 55, 56 in compression. The force is thus transmitted to the collar bracket 48 and post 38 to the head 26, which takes both the upward force upon the shoe and the downward force upon the cutter 34. A structure of such rigidity is thereby afiorded that the tendency of the work to chatter or to climb over the top of the tool is eliminated.

As above pointed out, it may be desirable to tilt the cutting tool and rocker up or down somewhat, either because of the character of the work and the resultant advisability of placing the cutting edge somewhat above or below the axis of rotation, or due to the fact that the vertical distance between the top of the cross slide and the axis of the spindle varies somewhat from the dimensioning for which the tool supporting assembly was designed. In either such event, the tool is fed horizontally into the work but the tool and the post 38 are somewhat tilted about the rocking axis of the rocker, and this tends to impart a corresponding tilt to the lower surface of the shoe l0. Such tilt of the shoe may be compensated, however, by so adjusting the screw 18 as to swing the shoe about the pin it to return the lower face of the shoe to horizontal position, or to a position parallel to the plane of movement of the cross slide. It will be seen that if the lower face of the shoe is horizontal, the feed will have no tendency to cause the shoe either to bind against or leave the work. As a practical matter, however, it is possible to adjust the shoe to a position as nearly horizontal as possible, judging simply by eye, and without the use of special gauging means. When thereafter the mechanic feeds the tool into the work, he may at the same time keep a wrench in engagement with the head of the screw 78 and tighten or loosen such screw as may be required during inward feeding of the tool to compensate for any undue tightness or looseness that may develop. He can detect the need for such adjustment by the ease with which the screw 18 turns. H i

It will also be noticed that by virtue of the parallel arrangement of the screw Bil withv respect to the axis of post 38 and the fact that angular adjustment may be made by swinging the collar 48 about post 38 as well as by swinging the arm 54 about screw Ell, the arm assembly 54 and the shoe carried thereby may be moved longitudinally with respect to the work, to carry them bodily toward or from the tool while nevertheless permitting the shoe to be arranged at any desired transverse angle. Thus when a cut is to be made close to a shoulder or other irregular configuration upon the work, the shoe may not only be moved along the work to clear, but may be arranged at any of a wide variety of angles to provide the best support and permit working very close to the irregularly configured portion of the work.

It will be apparent that various changes and modifications may be made without departure from the fair and intended scope of the subjoined claims.

I claim:

1. A holding and steadying device for cut-01f tools and the like comprising in combination with a tool holder having a shank adapted to be mounted in a suitable support and having a head adapted to carry a tool, said head having longitudinally separated portions movable toward and from one another to selectively grip and release a forming tool, means for so moving said portions comprising a clamping member bridging and engaging both of said portions and actuatable to move the same toward one another, a stud portion extending substantially vertically Lipwardly from and formed integrally with said clamping member, a, steadying arm carried by said stud portion and projecting therefrom, and means for selectively securing said arm to said stud portion at any of various positions of vertical adjustment.

2. Means for supporting and steadying a cutoff tool or the like comprising in combination with a tool holder having a shank adapted to be mounted in a suitable tool support, and having a head adapted to carry a work-forming tool, steadying means carried by said tool holder comprising an arm carried thereby and projecting forwardly from the head at an elevation above that at which the tool is supported, whereby such arm may overlie work with which the tool is engaged, two substantially parallel and vertical pivot means connecting the arm to the tool holder, and locking means for each of said pivot means, whereby the arm may be adjusted both angularly and longitudinally.

3. Means for supporting and steadying a forming tool during use thereof in a lathe or the like, comprising in combination, a tool holder having a shank adapted to be mounted in a, suitable tool support and having a head, means carried by the head for removably securing thereto a forming tool, and steadying means carried by said head comprising an arm supporting member carried by and extending upwardly from said head, an arm carrier mounted on and vertically movable with respect to said arm supporting member, said carrier being swingable about a vertical support axis with respect to said member, vertical pivot means carried by said carrier at a point spaced from the aforementioned axis, and a steadying arm carried by said pivot means and swingable about both the support axis and the I Ea'z'is of said pivot means, said arm being adapted to overlie work upon which the forming 12001 is working and to resist upward movement of the work with respect to the tool.

4. Means as set forth in claim 3 including a shoe member arranged below and supported by said steadying arm, and additional pivot means connecting the shoe to the arm for swii'igingg movement about a horizontal axis transverse with respect to the arm.

WILLIAM A. ST. JEAN.

8 REFERENCES CITED 7 The following references are of record in the file of this patent:

STATES PATENTS Number Name Date 407,972 Springer July 30, 1889 488,145 Hurley 1 Dec. 13, 1892 1,161,056 .Liebstein 1 Nov. 23, 1915 2,041,251 Klein May 19, 1936 2,324,316 Miiutin 1'. July 13, 1943

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