US2383991A

US2383991A - Die holder and tailstock center

Info

Publication number: US2383991A
Application number: US509561A
Authority: US
Inventors: Sarossy Albert
Original assignee: Individual
Current assignee: Individual
Priority date: 1943-11-09
Filing date: 1943-11-09
Publication date: 1945-09-04
Anticipated expiration: 1962-09-04

Description

Sept. 4,1945.- A. sARossY DIE HOLDER AND TAILsTooK CENTER y Filed ov. 9, 1943 iwf' nnnnnn INI/ENTOR.

V/llllllllll Patented Sept. 4, 1945 UNITED .sr-Ares PATENT 'OFFICE 2,383,991 Dm HOLDER AND TAlLs'roCK CENTER Albert lSarossy, West Orange, N.`J. l y ',applie'ationNovember 9, 1:94a, serial No.f5o9,5 61 v l (C1. iti-99) 8 Claims.

This invention relates to die holders vand .tailstock centers, and more 'particularly to Van imv provement therein.

'The improved die holder-consists of 4two parts, a die housing and a guide-bar, which may :be `ma'de in sizes suitable `for bench lathes vand for en'ginelathes. y

The `invention-consists in adie holder r1n wh1ch 'the threads Amay be out a't right angles, because the 'die rests flat -against the squarely surfaced recess 'in "the die housing. The die `'cannot vbe moved 'during the threading operation because it is 'securely locked. vIt is absolutely concentric with 'the stock to be cut and it remains so `because the die housing revolves freely around :a cylindrical part of vthe guide or improved :and novel "tailstock center. The thread is cut with 'a locked tailstock. The tailstock Vneed not be 'pushed-against the-stock while cuttingthe threads as "heretofore The die lhousing with Iits .dies yields longitudinally to any-pull of the work, Athus 'there is no dangerof stripping the thread caused by the weight'of the'tailstock. 'The smallest :force will Apull the die housing along the guide or vtailstock'center towards the -work piece-so that there is-no strain on -the thread. .The lathe may be `revolved at top speed `because `the `die `is held *.se-

`cure, 'and there isno-possibility of itfgetting out 'of alignment yfrom the workipiece, and `therefore ithe I`threads maybe cut 'faster and more effectively than heretofore, reducing the :cost `of opferation.

-In the iprior vart .the entire `tailstock was subfjected toa `pulling and/or pushing action when the workpiece was being worked on. :In the im- 9 provement, the weight or pull is Yso little that 'the iinest 'thread 'can be cut, and very delicate .workfcarried out, Abecause of thegive instead of` the pull. All .parts are axially in alignment, and aztrue cutis obtained.

The invention will be more fully described hereinafter, an embodiment yshown inthe drawing, and the invention will be nallypointedout inlthe claims.

.In the. accompanying drawing, y

'Fig. -l is `aA longitudinal section of the improved die holder andthe guide bar for the same;

Fig.'2 is anend view thereof,` partly broken away; p

LliigJS'is an end'view from the other end;

Figxl is Aa'section online 4--4 of Fig, 1;

tFig. i5 -is *af perspective view -showing the inser- *tion "f lthe die holder `vwith the guide '-.bar -in dttedllines;

Fig. 6 is a perspective vie. 'Lof'.the;guide-"liar;y

Fig. is a central longitudinal section of a tailstock with an improved -tailstock center, supporting the improved die holder and guide bar applied thereto shown in sideview and partly in section, and v 'i Fig. 8 is a perspective View of the tailstock, guide bar, and work piece, to show their operative relationship.

Similar characters of reference indicate cor-y responding pa-rts throughout the various views.,

l from rotating. In the manner well known, the

tailstock spindle t0 has a nut Mia or a direct thread engaging a tailstock screw 4I which -isv se. cured to a hand wheel I2, the rotation of lwhich wheel and screw slides the tailstock spindle -40 longitudinally. The work is indicated by I3, it beingsupported in a chuck' Ita in a manner Well known, as shown in Fig. 8.

The cylindrical member ortailstock spindle 40 has a tapered bore 42. Into this bore there is inserteda novel tailstock center hereinbefore referred to a guide bar having a tapered stem I6, having a shoulder Il, and a cylindrical holding and guiding portion I8. The tapered tailstock center and tapered seat in the tailstock spindle engage each other frictionally so that the new tailstock center does not rotate with respect to the spindle.

The cylindrical portion I8 of the tailstock center fits into a cylindrical bore I9 of a die supporting member 2D, `and has the shoulder I7 yabutting against the end wall 2l of the die supporting member 2D. This member 2,0 is rotatable and slida'ble on the portion I8. An oiler may be provided to permit oiling of the cylindrical part or shaft l8.` Oiling the cylindrical shaft I8 may be carried out by lany suitable means.

The member 2U has an enlargement 2li having a bore 25 snbcaliber to the [bore 19. These bores may be, if desired, of the same diameter asA the bore of the part 20 as in Fig. 8, or it maybe larger. The length of the bore '25 must be such as tojaccommodate the length Iof the entering end of the Work piece. The .bore .25 permits the yentry 0i the work piece I3 during the operation of the dies. 'Ihe outer surface of the enlargement is knurled. At the end of the enlargement circumferentially arranged set screws 2l preferalbly of the Allen type hold a threader 3l) or dies. The threader 30 is seated in a seat 30a, which seat [being at 90 to the axis of the threader assures that the axis of the threader is co-axial with the member 2U, and work piece. As known, the threaders are replaceable to conform to different sizes.

When it is desired to substitute one threader for another, the screws 2'I are withdrawn, one threader removed, and another threader substituted, and then the screws are again `fastened against the substituted threader.l f

Thus, the improved die holder consists of the novel die housing and the novel tailstock center |66 The tapered end `Ilia of the tailstock center or guide-bar dits into the tailstock` spindle proper. The die housing 2B fits over the cylindrical end of the tailstock center or guide-bar I6. It is preferalbly made of cold rolled steel and both are preferably case hardened to insure long wear. It is preferably made in several sizes, to hold standard size dies. It will hold dies to cut threads from the smallest to one-half inch diameter fine thread size or larger.

When .cutting thread the knurled part 24 of the member 2U is hel-d by hand pressure. After a few revolutions thethreading action will pull the member 20 forward on the guide-bar or tailstock center. The cylindrical stem I8 has scorings to indicate the length of the thread to be cut, preferably graduated 1A? apart. When the memiber 20 has moved slidably on the stem I8 the desired amount of thread length to be cut, the hand pressure on the knurled part 24 is released,

` then the lathe is stopped andreversed, the memberv 20 again held, and the work piece unscrews itself, pushing the member 211 back on the cylindrical portion I8. l

It will have been noted .that the 'member 20 moves axially o-n the guide-bar or tailstock center the amount of the length of the vthreaclrto be made, Wherelby a fast, delicate: and true action results.

A very iine adjustment is made possible by the use of the improved'device. First the work piece is supported in position. Then the part I il is longitudinally moved towards the work piece and fastened in position by nut Illa. Then the cylindrical part 40 is moved :by the hand wheel I2, all of which secures a very accurate adjustment of the die to the work piece. The fact that the member 2G axially and easily slides on the guide bar I6, removes any possibility of a pull `or push on the tailstock. Contrary to the old practice the work piece does not pull or push on the tailstock in its entirety, thus eliminating any possibility of stripping or marring the threads being cut. i

In the improved holder, there is a delicate axial movement on the stem, and this sliding action trues the threads.

Theimproved die holder for lathes is especially adapted for small threads'lbut may be adapted to larger threads and to turret lathes, or the like.

The improvement has special advantages for all shops,l especiallyfor the shopswho use it as an attachment for existing lathes without having to install separate vand special screw machines which might idle a large part of the time.

Due to the construction described, the improved device can'be adjusted inabout iifteen seconds, which is considerably faster than the time running into minutes required by the earlier forms.

An embodiment of the invention has ibeen described, but obviously various changes may be made in the details disclosed without departing from the spirit of the invention as setout in the following claims.

What I claim is:

1. A die holder for tailstock spindles comprising a die supporting member having a' bore for the entry of the workpiece, and having a sleeve having a cylindrical bore and a guide bar cylindrical at one end in registration with the cylindrical bore, and tapering towards the other end adapted for entrance in the tailstock spindle to be held thereby, said cylindrical end having graduated markings for indicating the desired movement of the die supporting member on its registering cylindrical portion, the cylindrical bore of the said member and cylindrical end of the guide bar being slidable and rotatable in respect to each other.

2. A die holder for tailstock spindles comprising a die supporting member having a bore for the entry of the work piece, and having a sleeve having a cylindrical bore and a guide bar cylindrical at one end in registration with the cylindrical bore and tapering towards the other end adapted for entrance in the tailstock spindle to be held thereby, said cylindrical end having graduated markings for indicating the desired movement of the die supporting member on its registering cylindrical portion, the cylindrical bore and cylindrical end being slidable and rotatable in respect to each other, said cylindrical member having a shouder limiting .its movement against the die supporting member, and said die holding member having a recessed portion at its end for holding a replaceable die, and having its exterior portion knurled.

3. In a die holder for tailstock spindles, the combination of a die holding portion having a die for actingy on a work piece at one end and an extended supporting portion at the other end having a bore of circular cross section, and a guidebar engaging the supporting portion in rotatable and axially slidable connection therewith, havwork piece Vwithout exerting any pull or push upon said guidebar.

4, In a die holder for tailstock spindles, the combination of avdie holding portion having a die for acting on a work piece at one end and :an extended supporting portion at .the other end having a bore of circular cross section, and a guidebar engaging the supporting portion in rotatable and axially slidable connection therewith, having a part conforming to said bore of the ,guide holding portion, and having a part adapted to engage non-rotatably and non-slidably, the .spindle of atailstock, and having means limiting the said slidable connection, permitting the die lholding portion with its die to move along with the work piece without exerting any pull or push upon said guide bar, ksaid die holding portion having a seat at right angles to the axis ofsaid .portion for the die to seat axially with said p01'- tion and the work piece.

5. A die holder for tailstock spindles comprising a die supporting member having a bore for the entry of a work piece and having a sleeve having a cylindrical bore, and a guide bar cylindrical at one end in registration with the cylindrical bore of the die supporting member and in axially slidable and rotatable connection therewith, and tapering towards the other end adapted for entrance in the tailstock spindle and to be held thereby.

6. In a die holder for' tailstock spindles, the combination of a die holder having a recessed portion at one end for the reception of. a die to act on a work piece and having a bore one end of which is in communication with the bore of the die for the passage of the workpiece into said bores, and having a bore at the other end of the die holder of circular cross section, and a guidebar for said die holder having one end of substantially the same cross section as that of the circular bore, and having its other end of a coniiguration to register with the bore of the tailstock to be locked therein, whereby the die holder and support are in rotatable and axial relationship with each other during the action of the die upon the work piece, avoiding any pull or push upon the support or upon the tailstock.

'7. In a die holder for tailstock spindles having a bore tapering inwardly, the combination of a guidebar having a part tapering outwardly adapted to rictionally engage said bore against rotation and having a part forming a cylindrical` extension, with a shoulder disposed between said parts, and a, die supporting member having a cylindrical bore of substantially the same diameter as that of the cylindrical extension for rotatably and slidably engaging said cylindrical extension, and having at its other end a die for acting upon a workpiece, and a bore for the entrance of the workpiece held by a chuck, whereby upon the workpiece being operated upon by the die, the die supporting member longitudinally moves on said cylindrical extension, said shoulder limiting said movement, with the cylindrical extension remaining stationary, so that any pull or push of the work piece is taken up by the diesupporting member in axial longitudinal movement without exerting any pull or push upon the cylindrical extension or upon the tailstock.

8. In a die holder for tailstock spindles having a bore tapering inwardly, the combination of a guidebar having a part tapering outwardly to frictionally engage said bore against rotation, andhaving a part forming a cylindrical extension, with a shoulder disposed between said parts, and a die supporting member having an exterior knurled portion and a, cylindrical bore of substantially the same diameter as that of the cylindrical extension for rotatably and slidably engaging said cylindrical extension, and having. at its other end a bore for the entrance of a work piece and a recessed portion for a die for acting upon the work piece, whereby upon the work piece being operated upon by the die, the die supporting member longitudinally moves on said cylindrical extension, said shoulder limiting said movement, with the cylindrical extension remaining stationary, so that any pull or push of the Work piece is taken up bythe die supporting member in axial longitudinal movement without exerting. any pull or push upon the cylindrical extension or upon the tailstock, the die supporting member being held by hand onv the knurled portion against rotation during the operation of the die upon the work piece, and released for rotation with the workpiece upon the completion of the work.

, ALBERT SAROSSY.