US740016A - Self-opening die. - Google Patents

Description

No. 740.016 PATENTED SEPT. 29, 1903..

L. A. HOWE.

SELF OPENING DIE.

APPLICATION FILED JUNE 15, 1903.

N0 MODEL.

Patented September 29, 1903.

' .UNITED STATES PATENT OFFICE.

LEWIS A. HOWE, OF BARRE, MASSACHUSETTS, ASSIGNOR on ONE-HALF To HARDING ALLEN, OF BARRE, MASSACHUSETTS.

SELF-OPENING DIE.

SPECIFICATION forming part of Letters Patent No. 740,016, dated September 29, 1903.

' Application filed June 15, 1903. Serial No. 161.446. (No model.)

' To all whom it may concern.-

Be it known that I, LEWIS A. HOWE, a citi zen of the United States, residing at Barre, in the county of Worcester and-State of Massachusetts, have invented a new and useful Self-Opening Die, of which the following is a specification. r

This in vention relates to that class of threadcutting dies in which the threading-jaws are separated to permit the withdrawal of the work.

The especial object of this invention is to provide a setting mechanism for a self-opening die which will set the threading-jaws to two difierent positions, the more, open position being used for a roughing-out out, while the second position of the jaws is used for the finished chip or cutting of threadsto exactly the desired size. I

This invention is shown as an improvement upon the threading-die shown,described, and

claimed in the application for patent. filed by me November 28, 1902, Serial No. 133,140.

In the accompanying drawings, Figure l is a side View, partially broken away, of a threading-die constructed according to this invention. Fig. 2 is a front View thereof, partially broken away, showing the threadingjaws in their open or separated position. Fig. 3 is a front view showing the threading-jaws in their partly-closed or roughing-out position. Fig/iris a similar view showing the threading-jaws in position for cutting the finished thread, and Fig. 5 is a detail view of the pin for setting the movable threading-die to its roughing-out or thread-finishing position. Two forms of dies are now commonly em.- ployed for cutting screw-threads. 'For ordinary purposes-for example, in .an ordinary die-stocka solid or fixed die may be employed, which has to be run back over the threads when work is being removed therefrom. Reversal of a die to run the Same back over the threads which have been formed or cut thereby is objectionable, for the reason that the back travel of the die injures and mars the threads and at the same time dolls and quickly wears out the threading-teeth.

For better classes of work self-opening dies are now employed in which the threadingteeth are moved away from the work when a thread has been completed, so that the work can then be withdrawn without running the die back over the threads.

In my prior application for patent, before referred to, I have shown, described, and claimed a self-opening die comprising a baseplate with laterally-separable members which are movable toward and away from the basev plate, with pins extending from the base plate to engage sockets in the laterally-separable members to hold them in operative position, but permitting them to separate when moved away from the base-plate and ofl of the ends of the pins.

In the construction shown in my aforesaid application for patent the pins are rigidly secured in the base-plate.

Theespecial object of my present invention is to provide simple and efficient means for adjusting one or both of these holdingpins in a die of the class described, so that the threading-teeth may be set for a roughing chip to cut a thread of approximately the desired diameter and may afterward be set together to finish the thread exactly the right size. To accomplish this result, .in practice I have found that this can be conveniently done by pivotally mounting the movable pin in the base plate and providing the pin at its end with an eccentric or o'fiset portion for engaging one of the separable members, and by means of this construction when the pin is turned to one position one of the separable members will be moved slightly away from the work in position for a roughing-out cut, and when the pin is turned to another position the separable members willv move to their closed position to cut threads of the accurate size.

Referring to the drawings for a detail description of a die embodying this invention as illustrated herein, the die comprises a hollow spindle or shaft 10. Carried by the spindle 10 is a base-plate 11. Driven or otherwise fastened in the base-plate 11 is a stationary holding-pin 12, and pivoted in the base-plate 11 is a movable holding-pin 4.0. Adj ustably mounted on the pins 12 and 40 is a guide-piece 13. The guide-piece 13 is movable upon its pins toward and away from the base-plate, the limit of its forward movement being regulated by a stop-screw 14.

As shown most clearly in Fig. 2, the guidepiece 13 has a transverse way or slot out therein, and fitting into this slot are separable dieholding pieces 15, which are provided with extending flanges holding them in place in their slot.

Adjustably mounted in the separable pieces 15 are the two-part dies. Each of these twopart dies is fastened in place in its holder 15 by fastening-screws 19, and the dies are set to position by end screws 20.

The separable die-holders 15 are normally separated by a spring.

As herein illustrated, a screw 21 is threaded into each of the die-holders 15. The screws 21 extend out through slots in the guidepiece 13, and mounted on the screws 21 are telescoping sections or tubes 22, containing a spring 23.

Any ordinary means may be employed for regulating the length of thread cut by the die. For example, an adjustable pencil or spindle 25 may be fitted within the hollow spindle 10.

Referring now to the pivoted pin 40, it will be seen that this pin 40, as illustrated most clearly in Fig. 5, is provided at one end with an eccentric portion which engages one of the die-holders 15, and secured on the other end of the pin 40 is an operating-handle 42.

Considering now the operation of the selfopening die in the actual work of cutting a screw-tn read upon a rod or bolt, the parts of the die are first set to the position illustrated in Fig. 3, and either the work or the die itself, as the case may be, is turned, and after the work has entered between the cuttingjaws of the die the end of the work will advance into the die until it engages the end of the adjustable stop or red. This will cut or rough out a screw-rod slightly larger in diameter than the finished thread of desired size. When the end of the work strikes the stop, the laterally separable members will be pulled off from the ends of the pins and the die will be opened to the position illustrated in Fig. 1. The die is then again closed, the handle 42 is turned to the position indicated by dotted lines in Fig. 4, and by again running the die over the work a finished thread of exactly the desired size will be obtained.

I am aware that numerous changes maybe made in practicing my invention by those who are skilled in the art-that is to say, numerous other means may be devised for setting and adjusting one of the holding-pins instead of using the pivotal eccentric arrangement I have herein described. It is also to be understood that, if desired, both holding-pins may be made adjustable, although in practice I have found that sufficiently accurate results may be obtained by simply setting or adjusting one of such pins. 1 do not wish, therefore, to be limited to the special construction I have herein shown and described; but

What I do claim, and desire to secure by Letters Patent of the United States, is-

1. In a self-opening die, the combination ofa base-plate or support, laterally-separable members which are movable toward and away from the base-plate, pins extending from the base-plate to engage sockets in the laterallyseparable members to hold them in place, but permitting them to separate when moved away from the base-plate and off the ends of the pins, and means for adjusting one of the pins to enable the die to make a roughing cut before cutting a screw-thread of the desired diameter.

2. In a self-opening die, the combination of a base-plate or support, pins extending from the base-plate, aguide-piece mounted on the pins and movable thereon toward and away from the base-plate, and laterally-separable members mounted in the guide-piece and having sockets to be engaged by the ends of the pins when the guide-piece is in its normal position, but which are disengaged from the ends of the pins when the guide-piece is moved away from the base-plate, and means for adjusting one of said pins.

3. In a self-opening die, the combination of a base-plate or support, pins extending therefrom, a guide-piece mounted on the pins and movable thereon toward and away from the base-plate, laterally-separable members with socketsfor receiving the ends of the pins mounted in the guide'piece, dies adjustably mounted in the laterally-separable members, and means for adjusting one of the pins to set the die for roughing or finishing cuts as desired. I

4. In a self-opening die, the combination of a base-plate or support, laterally-separable members movable toward and away from the base-plate, and pins extending from the baseplate to engage sockets in the laterally-separable members, one of said pins being pivoted in the base-plate and having a handle for turning the same, and having the end thereof which engages one of the separable members eccentric with respect to its pivot, whereby the die may be set for roughing or finished cuts, as desired.

In testimony whereof I have hereunto set my hand in the presence of two subscribing witnesses.

LEYVIS A. HOWE.

\Vitncsses:

JAMES CRANE, C. II. FOLLANSBY.

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