US2600776A - Threading die - Google Patents

Description

C. H. INGWER THREADING DIE Filed April 12, 1948 June 17, 1952 2,600,776

v INVENTOR.

CARL H. I NGWEE iyw Patented June 17, 1952 UNITED STATES PATENT OFFICE 2,600,776 "THREADING DIE Carl H. Ingwer, Elyria, Ohio, assignor to The Ridge Tool Company, 'Elyria, Ohio Application April 12, 1948, Serial No. 20,379

2 Claims. 1

This invention relates to improvemennts in threading dies and more particularly to an improved die head such as is used for threading pipes, having a novel arrangement for holding the thread cutting chasers. The invention is an improvement over the die shown in my Patent No. 2,242,954, of May 20, 1941.

Previously, die heads have had complicated mechanism for holding the chasers; in some cases requiring especially designed chasers. In addition, in the construction of the various parts, it was often required that special machinery be used to finish each part. In other cases, complicated castings or die castings were required. It often happened that because of the peculiarity of the manufacturing processes required, it was virtually impossible to use any material other than the specific one for which the piece was designed.

By the present invention, it is possible to manufacture a die stock without the use of expensive and not-so-strong die castings and without use of complicated and expensive machining operations. In addition, by my invention, the need for complicated cores to make the castings is eliminated, and those parts which must have additional strength are so designed as to lend themselves readily to a forging process.

The construction is such as to allow the various parts to be machined in a simple and easy manner without special equipment. Furthermore, the design enables the chassis to be held with great rigidity while enabling them to be replaced easily and quickly as well as revised, should the occasion demand it.

All of these advantages and other advantages, as well as the economies in manufacture, will be more apparent from the description of the invention which is illustrated in the accompanying drawings.

Fig. 1 is a side view showing the die stock completely assembled;

Fig. 2 is a view of looking at its face;

Fig. 3 is an exploded section of the assembly showing each piece in its proper relation to the others;

Fig. 4 is a view of the underside of the face plate showing the positioning and strengthenin lugs;

Fig. 5 is a top view of the die body;

Fig. 6 is a view of another face plate for a larger die showing the post and chaser engaging lugs; and

Fig. '7 is a fragmentary elevational view showing the chip discharge opening in the die.

Throughout the drawings like parts are designated by like reference characters.

In general, the die comprises a body which has a sleeve or barrel adapted. for connection the assembled die stock 2 to a handle which may be of the ratchet type. The thread cutting chasers are supported by the body and are held in place by a face plate which positions them and clamps them in the body.

More specifically, the body It comprises a sleeve part ll for engagement with a ratchet wrench and has a base [2 which is ring shaped. The base supports four post-like members 13 which extend parallel to the axis of the sleeve and are equally spaced around the base. This body It] may be formed of a casting, although it is not limited to such formation with the external surfaces machined together with the pipe guiding bore [4. This machining is not necessary but lends a finished appearance to the tool. The end faces 15 of the posts l3 are finished normal to the guiding bore [4. Radially and longitudinally extending channels it, for holding the thread cutting chasers, are then machined through the posts IS in diametrically opposed relationship by milling across the end of the body. Parallel to these channels, lug-engaging shoulders I! are machined on the posts 13. The sidewalls of each channel it are parallel to each other and at a fixed distance apart and are also parallel to the sides of the shoulders ll. The bottom of each channel I6 is square with the side walls and with the guiding bore It in order to provide for the proper alignment of the thread cutting chasers I8 which are carried therein. Threaded holes i 9 are provided in the posts iii to receive screws as hereafter described.

The thread cutting chasers I8, Fig. 3, are provided with parallel sides and a top and bottom at right angles to the sides for engagement with the sides and bottom of the channel 16. Thread cutting teeth 20, which may be of conventional design, are provided on one end of the chaser.

Grooves 21 of trapezoidal cross section having a perpendicular side toward the teeth and in a fixed position with respect to the teeth, are machined transversely in the top and bottom of each chaser.

The face plate 22, which may be a forging, is generally ring shaped having an outer diameter 4| substantially the same as the periphery of the base [2 of the body Ill. The inner diameter 42 is such as to provide sufficient clearance with thematerial on which threads are being cut. Countersunk holes 23 are provided in the face plate for reception of oval head machine screws 24 which extend therethrough and are threaded into the tapped holes l9 in the posts I3 to hold the plate 22 in place.

The side of the plate adjacent to the body Ill is provided with four lugs 25 equally spaced around the ring and located at a predetermined distance from the center line of the face plate 22. These lugs 25 are shaped to fit into the grooves or notches 2! in the chasers l8 and are 2| in the chasers 18.

18 by holding each of the posts in a fixed rela-.:. tion to each other and preventing the ends of.v

the post from spreading apart.

All these lugs may be forgedrroughly...on,thei face plate 22 and can then be easily machined.

to dimension. For instance, there couldube a boss, the outlines of which are indicated by' the dotted lines 40 in Fig. 4 and this boss machined.-

The manner in which this to provide the lugs. is done is best shown in connection with Fig. 6 which is a view of a face plate for a larger diethanthatzshown' in the other figures.- The manner .of construction-is, however, substantially the same for either of the plates.

It will be noted that the inner surface 25a of the-lugs 25 is on a line with the surfaces 26a of the lugs 26, which line-is a chord across the plate. This enablesrthe plate to be manufactured by; a forging process whereinthe .plate is formed with four solid bosses of: a contour as best shown in Fig; 6 by the lines 30.

At this time theboss Zia-is roughly formed, having the outer slanting-surface 251), the space 250, and 25d on opposite sides beingnearlysflush with the surface of the plate outside of the lug.

Subsequently to the forging operation, the lugs 25 and26 are formedbyafew simplemachining operations. This may be effected by milling the channels 3| transversely across the plane as indi cated by the dot dashglines 32.- The channels33 are likewise milled bya cutter as indicated by the dot dash lines 34.

It will be noted ,thatthe ,milling operation which;.forms the faces 26av and'25a' on thelugs 26 and .25 respectively may .be such as shown in Fig. 4 that all of the roughlug .40 is removed from these surfaces to the center hole 42. It has beenifound that this leaves the lugs 26 sufficiently large .and strong tozprovide the proper support for the posts.

In the case of the face plate of Fig.6, however, where the-die is to ibe usedrfor threading larger pipe,;it may .be desirable to provide a largerlug 26.1 Since the milling-operation forthe groove 34 is primarily to determine the exact vpositionof theface 250. on the-lug 2,5, the milling'cutter in this. instance may be :narrower and parts of the lugZG will be left oneach 'side of the slot 33,,thus providing a broader surface; for; engaging the seatsor shoulders 11 of --the'posts. Also during the forging operation, the lugs 30,; Fig, 6, are formed with fillets 35 which provide additional reinforcement for the'lugs as well-as providing a :more symmetrical contour for the chip relieving openings between the posts on the assembled die asbest shown in Fig. 7.

Theassembly of the device can; be easily ac complished by placingthe thread cuttingchasers H3 in the channelslfi withjgthe teeth inward. The face plate-22 is'then placedover the body with the positioning lugs engaging thexgrooves The supporting lugs ,26 will engage the shoulders-l! onrthe posts .I3. The screws 24 are then inserted through the holes 23 and screwed into the tapped'holes 9 and screwed :down securely. The chasers are: then 4 securely held in position and the posts 13 are supported in fixed relationship to each other.

It will be seen that all machining of the channels, shoulders, and lugs consists of simple operations, primarily straight cuts: across either the body or the' face place requiring no special tools.

It should also be noted that because of the manner in which the face plate engages the posts (the lugs being on each side of the post) that greatstreng-th-is given to the posts Without the needzof" thebridging portions as shown in the previously mentioned patent. This facilitates the ease with which the parts may be made, eliminating expensive cores previously needed.

Although the device is shown with four chasers, it is obvious that the number of chasers may be varied without departing .fromthespirit or the scope of my invention. Still other departures fromthe structureshown will be apparentito those skilled in the art which may belmade without departing from the spirit of the invention.

I claim:

1. A threading dieincluding a-body having a central work-receiving opening therein; a plurality of" posts onsaid body extending co-axially around the-work receivingopening, said posts having diametrically opposed; chaser slotsv and being formed. withfshouldersson the outer surfaces-in spaced parallel relation. to said. slots, chasers substantially filling; said-slots and each having a lateral notchin at leastone edge .there-, of and: thread cutting teeth alonggone end, each of-isaid notches having ones face substantially parallel to the axis of the body, meansto hold said chasers rigidly in said slots-andnto holdthe posts againstspreading .comprising, :a face plate havinglugmeans, each of saidlug means having a flat face; in-positioning engagement with said one face in the notch-of each; of' said chasers to positively determine g-the' radial position of said chasers insaid slots and having lug meansinengagement with ,saidshoulders thereby supporting said posts-on :both,=;sides thereof; and means to hold said plate to. said-posts.

2..- A threading die includ'ing ajbody .having a central "work -receiving opening j therein, a V a plurality "of posts on; said body; extending a coaxially aroundthe work greceiving opening, said posts having diametrically-opposed chaser slots and being formed with-shoulders, :in spaced parallel relation to. said slots and on; opposite sides there- 01; chasers substantially vfilling, said slotseach chaser h'avingt a notch :in; at least-one edge thereof and thread cutting teeth alongon'e end-means to hold said chasers rigidly in said slots and to hold the. posts against spreading comprising; a face plate having lug means in-positioning: engagement in the notches ofsaid-chasersin said slots and having lug means in, engagement with said shoulders on opposite sides of, said posts, and means to jhold-saidplate. to said posts.

CARL 'H. IN GWER.

REFERENCES" CITED" The following: references are. ofv record in J the file of this-patent? UNITED STATES PATENTS Number Name 1 Date 1,803,484 Pealer May 5. 1931 2,242,954 Ingwer- May 20,"1941-

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