US1584898A

US1584898A - Threading die

Info

Publication number: US1584898A
Application number: US656766A
Authority: US
Inventors: James A Smith
Original assignee: Individual
Current assignee: Individual
Priority date: 1923-08-11
Filing date: 1923-08-11
Publication date: 1926-05-18
Anticipated expiration: 1943-05-18

Description

May 18 19:26. 1,584 ,898

J. A. SMITH THREADING DIE Filed August 11, 1923 INVENTOR. 2&

ATTORNEY- Patented May 18, 1926.,

v JAMESZAQ" SMITHfOFWTNDSGR, 'CONNE'C'IIGUT.

*ITHREADING1DIE.

dfipplidation filed August 11, .*1 923. SeriaI--No. 656,7.66.

. .My invention relates totthe class 'ot-Ldei i'ces -ithat are' eniployed for cutting screw threads, and an ob ect ofrrny invention among others,

.isthe production in asrapidzsimple,

*- 5 expensive mannerofma andin- (116 having improved features as to its characteristics.

Myiinproved die-andthe nannenoticreat- "ing -itaand inthe-const-ruction and useot which theobjects: herein others,rn ay be-rattained, iacconipanyingadrawings is illustrated'in-the in Which- .-nary-stepsin theimalrin have been taken.

,- Eigurezfzrisia View in the same.

a Figure 3 is g o 'my mp d die 1. .r

s 111g those, -'port1ons which .traveli-ahead When thetool is rintolan d take hold .ofthe, piece upon which lathread is to be cut, andthus to begin'lthe f thread cutting operation upon such piece and set out,-as well-res v I parts located between lthe chip or clearance holes. and extending tow i pered fbEICkV ardly from? cross section thr-ough I view-similar to Figurewlibut i-illustratingian advanced stepan the operai crosssection through View sini-ilar to Fig -=n-re1 but illustratinga sti ll-lfurther and-ad- Figure 6 is a View in the same.

, :Fagure'? 1 -15 avanced step in the making oft-he die. I

cross section through :1 V I -erable. I side view of astool devised a. by .me *for. use intcarryang put any invent-ion,

\ of the itool.

Figure 8 is an end View of saidtool.

'IeW .of improved -v die in its completed. tforrn.

through the sarne.

Figure l 11 a enlarged, lthrough plane denoted by GFi'gure 410 .is -.a view in cross section =il lustrate-the improved characteristics ot the die.

In-the making -.of Idies rfor cutting-screw threads {past to lpiecerof it hasI-been common practiceuin the le in :the center of a -.-1naterial to :constitute t die, Which hole is then tapped. Then a'nurnberiof chip =or clearance holes are -i these lbei-ng located 1 thread cutting rbetween": the center irnade in the piece,

material ance holes to be eventuallygcntaway. g

In :order to cause .the cutting ithreads of 'the center and I threade d holezto readily cut td'leaditdnto the diei thevzthroat of the cenxter and thread cutting hole; issprovided with what "may .be aptly termed. a 'lead 1' that takes lthe .fornr of. a bevel that .xexten'ds in the direction 7. of depth of 'the .hole on the cutting. portions or -lands,,z;which .arelthose ar'dsthe center'of :Ithel'die and these beveled parts arealso tathe front to'therear edges or such lands, saidfront edges beoperating to cut a thread.

t In:for1n1ng this "'tlezid it L-h'as been; custo-niary heretofore to employ -az'file, arid in some instances IHL'lllHgutOOl. has been. used,

Ybutfei'ther. operation takes. much time and reman :lexpenslve ope-ration,

.. intheiformation ensure I this View also illustrating the manner: of use A g V. efficient manner and lwlthout requir ng 3 an quires great \care Hand considerable skillto aVOidJmu-tilatiQn of threads other than those :upon which" the work. is being done. lOonse qnently the" formation for suchllea'da-has been original expense of the die" has been consid- .By employing vraydin proved construction ram enabledflto produce-such diein ia particularlyrapid and .dncing'the cost of, producing the die, and'at the=same time-I am enabled to provide, afdie that isnmore durable than lthoseihavifngithe- Qlea-d ,;produced by s a cutting operation as her ei nbefore .r'eferre'dfto.

I V 'lIn =constructing my lmprovedd1e I first take a piece ofniaterial 10, oft-the. desired .form, as roundor rectangular in cross section, and drill a lcen- ,liter or thread ciitting'hole '11 therein; which hole is eventuallybeveled at its. mouth or V at equaldistances apart and at such -.distances ifrorn the center and *lioleas toenablelthe hole and the'ehip orflclea'r- 1 man the same as-1 manzner of forming I having such lead is,-

muzzie to. produce 5 the iflead', as herein'betfore described with respect' to;;-prior.dies," the form .or shape of .thisi-lead being substanthat. of,prio'r dies. JThe this llead and the die however, aniinpoi'tant feature or any present invention, which" c'f ntemplates the formation of such 'lea'd by compressing or condensing the .metal fat the month of the thread cutting hole .11 and conseqnently atthe entering ends; of thela'n' ds '13, which compressing or condensing of: the metal may be (effected i in any desired Trianan'd; Tthereforathenor, preferably by swaging. In the preferred manner of effecting this compressing or swaging operation, I employ a swaging or lead forming tool 12, properly shaped, and which is forced into the mouth of the hole to mold or swage the material of the lands about the mouth of the hole to the desired shape to produce the lead. This operation of forming the lead may take place at different stages in making the die, but I prefer to form, such lead as one of the preliminary steps in the operation. It will be found, however, that such lead may be formed after the center and thread cutting hole has been threaded, but by forming it before such threading, distortion of the threads is avoided and a subsequent operation to correct the distorted thread is not required.

In forming the lead of the die as herein contemplated I preferably construct said tool 12 with its working end properly shaped to produce the lead. This end of the tool is beveled to a degree to produce a beveled edge 14L of proper shape at the mouth of the thread cutting hole 11 and on the lands 13 should they exist at this time, and in order to properly shape the end of each land as to taper I provide as many swaging faces 15 on the tapered end of the tool as there are lands in the die to be made. These faces are tapered from a ridge 16 at one edge of each face to the bottom of a groove 17 that terminates at the perpendicular edge of the adjacent face, and as shown in Figure 7 of the drawings. In other words, each of the faces 15 of the tool is of a shape to correspond both in bevel and taper to the ends of the lands in the mouth of the hole in the die to be made, and when the tool is forced into the hole 11 those portions of the piece that will eventually comprise the ends of the lands 13, if the swaging be done in a preliminary step in the operation, or those portions constituting the ends of such lands, if the swaging be done after the formation of the threads, will be properly formed both as to tappr and bevel to produce a most etiicient leac.

When the swaging takes place as a preliminary step in the operation I preferably first form the center hole 11 and then the chip or clearance holes 18 are made. The tool 12 is then employed to produce the lead, as shown in Figures 3 and at of the drawing, the thread 19 may then be produced, as illustrated in Figures 5 and 6 of the drawing, and the entrances 20 to the chip holes 18 may then be cut in any desired manner to produce the completed die as illustrated in *igure 9.

IVhen the lead is produced as a more advanced step in the operation, the work of the swaging tool is effected after the forma tion of the threads, and preferably after the chip or clearance holes 18 are made. It will,

therefore, be obvious that this swaging operation may take place at various stages in the construction of the die and I do not, therefore, limit my invention to the swaging as taking place at any special step in such construction.

A die produced as hereinbefore described has the metal of a working portion, that is the lead on the ends of the lands 13, compressed and condensed, with a consequent beneficial result of a cutting edge having increased durability over a die in which the metal is not condensed.

The bevels forming the leads on dies of various sizes are substantially the same, and it will, therefore, be obvious that a single swaging tool may be employed to bevel dies of .a wide variety of sizes. A die produced in accordance with my invention will possess a maximum degree of uniformity as to the several cutting portions thereof, such uniformity greatly exceeding that possessed by a die in which the several cutting operations are separately performed by hand work.

In accordance with the provisions of the patent statutes I have described the principles of operation of my invention, together with the device which I now consider to represent the best embodiment thereof; but I desire to have it understood that the device shown in only illustrative, and that the invention may be carried out by other means and applied to uses other than those above set out.

I claim 1. A threading die having a thread cutting hole comprising a lead, with the metal comprised in such lea-d more dense than the metal comprised in parts of the thread cutting hole, thereby toughening a cutting part of the die.

2. A threading die having a thread cutting hole with a beveled mouth forming a lead, with the metal comprised in such lead more dense than the metal comprised in other parts of the hole, thereby toughening the cutting edge of the thread cutting hole in the die.

3. The process of forming a threading die that consists in making a thread cutting hole in a piece of material, and as a step in the process forcing the beveled end of a lead forming tool having backwardly tapered faces into the mouth of the thread cutting hole to compress the metal and form a lead.

a. The process of forming a threading die that consists in making a thread cutting hole in a piece of material, and as a step in the process compressing the metal at the mouth of said hole to form a lead, and afterwards threading said hole.

5. The process of forming a threading die that consists in making a thread cutting hole in a piece of material, beveling the edge of said hole" to form a lead, cutting chip or clearance holes before the beveling operation which holes are opened into the threadcutting hole, and afterwards threading said thread cutting hole.

6. The process of forming a threading die that consists in making a thread cutting hole in a piece of material, forming clearance holes in said material with landportions therebetween, and as a step in the process forcing the beveled end of a lead forming tool having swaging faces larger in diameter than said thread cutting hole into the mouth of said thread cutting hole and against the lands to compress the metal thereof to form a lead, and also, as a step in 1the process, threading said thread cutting 7. The process of forming a threading die that consists in making a thread cutting hole in a piece of material, forming clearance holes in said material with land portions therebetween, and as a step in the process forcing the backwar-dly tapered annularly disposed swaging faces on the beveled end of a lead forming tool, said faces corresponding in number and location to said lands, into the mouth of said thread-cutting hole and against said lands to compress the metal thereof to form the lead, and also, as a step in the process, threading said thread-cutting hole.

JAMES A. SMITH.