US2251336A

US2251336A - Die and die holder

Info

Publication number: US2251336A
Application number: US286575A
Authority: US
Inventors: Judge Franklin
Original assignee: Greenfield Tap & Die Corp
Current assignee: Greenfield Tap & Die Corp; GREENFIELD TAP AND DIE Corp
Priority date: 1939-07-26
Filing date: 1939-07-26
Publication date: 1941-08-05
Anticipated expiration: 1958-08-05

Description

8- F. JUDGE 2,251,336

DIE AND DIE HOLDER Filed July 26, 1939 n 24 I9 I2 22 as l6 (ATTORNEYS Patented Aug. 5, 1941 DIE AND DIE HOLDER- Franklin Judge, Greenfield, Mass, assignor to Greenfield Tap and Die Corporation, a corporation of Massachusetts ATE OFFICE Application July 26, 1939, Serial No. 286,575

2 Claims.

This invention relates to thread cutting diesand holders therefor and particularly to such dies and holders in which the holder is adapted radially to adjust the die sections accurately to determine the thread dimensions.

The object of the invention is to provide a convenient means for predetermining the setting of the die to desired adjustment.

.A further object is to enable the operator to ascertain readily the adjustment necessary for a given depth of thread.

In the accompanying drawing:

Fig. 1 is a sectional elevation of the die and holder;

Fig. 2 is a plan view looking in the direction of arrow 2 in Fig. 1.

Referring to the drawing, Fig. 1 shows a threading device comprising a holder H), a die II, a cap I2, and a lock nut I3. The holder I6 is provided with diametrically opposed lugs I5 adapted to be received in recesses It in the inner face of die II.

The die II is provided with upward extended threading prongs or lands [1, threaded on the inside I8 and having a conical outer surface I9 so that the end of the die is frusto-conical in shape. The cap I2 is provided with an upper annular portion 20 and a lower portion 2|. The upper annular portion 26) is provided with a conical recess 22 engaging the conical outer surface I9 of the threading lands H. The lower annular portion 2| is internally threaded to fit externally threaded portion 23 of the holder IE1.

The cap I2 fastened on the holder l bears against outer conical surface 22 of lands ll, securing the die II in place against holder III with lugs I positioned in the recesses I6, the conically surfaced ends of the lands ll projecting through and beyond the forward end of the cap I2. The rotative and axial movement of the cap II relative to the holder I0 provides a tightening pressure on the outer surface of lands H. The prongs or lands II fiex under the tightening pressure of the cap I2 on the outer surface 22, providing a means for adjusting the thread cut by the die. As the cap I2 is tightened against die II the cutting bore 24 of the die is lessened. The diameter of the threaded screw is determined by the bore 24 of the threads I8 as set by the cap I2. When screws are threaded by the die to close tolerances a setting is made of the cap l2 and a sample screw threaded. If this is over or under the measurement sought, the die II is corrected by adjusting the setting of the cap I2.

In order to provide for the reading of the initial setting of the cap I2 and the determination of the correct adjustment required to bring the screw size within the tolerances allowed a scale 25 extends around the top side of the upper annular portion 2t of the cap I2. The lines and numbers of the scale 25 are added on the bevel side of the cap and each land I1 is provided with a zero line 28, said zero lines being equally spaced with relation to each other and the number of divisions of the scale 25 is some multiple of the number of the zero lines. Thus the position of the rotating cap can be read against the zero line on any of the lands and the scale 25 may be graduated to any convenient part of the cap rotation corresponding to a fraction of the adjustment of the die. For example, each scale division may represent one-thousandth of an inch of die adjustment and of the corresponding adjustment of the thread depth. The graduations of scale 25 are evenly spaced and the total adjustment plus or minus between successive zero lines is sufficient to take care of any normal readjustment of the die from the trial setting.

The graduation of the top of the cap 12 with a number divisible by four, corresponding to the four lands, provides means for reading the setting of the cap l2 on the die II and holder I ll from all zero lines 26 by reading the setting at any one of the lands. For instance, as shown here there are thirty-six graduations; if the setting at land A is six, the setting at land B is six plus the nine graduations between each land, or fifteen. The readings at lands C and D, correspondingly, are twenty-four and thirtythree. 1

The provision of these graduations facilitates the process of readjusting the cap I2 on die II after a test screw has been threaded. Before making the trial the original setting of the cap I2 in relation to the Zero line on any land I1 is read. This setting will give the readings on the other lands by adding or subtracting the number of graduations between each land. Thus the operator, knowing the correction to be made after the sample threading can adjust the cap I2 on the die II against any of the lands I1 whether the setting for that land was originally read or not so that the readjustment may be made readily Whatever the position of the holder with relation to the operator.

For instance, if the original setting was six at land A, it was fifteen, twenty-four, and thirtythree at lands B, C and D respectively. If the correction is plus one it can be made from any one of the zero lines, fifteen to sixteen at land B, twenty-four to twenty-five at land C, thirtythree to thirty-four at land D, six to seven at land A.

I claim:

1. An adjustable die structure comprising a die having a frusto-conical end divided into separate lands relatively radially adjustable, of a holder for the die comprising a body portion and a relatively movable cap housing the die and having a forward end surrounding and contacting the conically surfaced ends of the lands projecting through and beyond said forward end of the cap member whereby slight radial adjustment of said die lands is efiected by rotative and .axial movement of the cap relative to the holder,

and a die marking at a corresponding point on each of said lands adjacent said cap, said die markings being equally angularly spaced with relation to each other around the axis of the die, and a cooperating 360 circular measuring scale on the end of said cap having the number of its equally spaced divisions a multiple of the number of lands of the die and showing the adjustment of the die sections by the position of said cap divisions relative to each of said die markings.

2. An adjustable die structure as set forth in claim 1 in which the separate lands of the die are integrally connected by an annular ring at the base of the prongs.

FRANKLIN JUDGE.