US1118180A

US1118180A - Process of making steel die-punches.

Info

Publication number: US1118180A
Application number: US77888913A
Authority: US
Inventors: Andrew J Bradley
Original assignee: Individual
Current assignee: Individual
Priority date: 1913-07-14
Filing date: 1913-07-14
Publication date: 1914-11-24
Anticipated expiration: 1931-11-24

Description

A. J. BRADLEY.

PROCESS OF MAKING STEEL DIE PUNGHBS.

APPLICATION MLPD JULY 14, 191s..

1,1 18,180', Patented Nov. 24, 1914.

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\ nunlmliunlllll In IIIII@ In HINIIlIIl lI nl "um lll "Immlu 3 A' HQI I Immun EW um 5f l II IMI l llllllllllizlmlllllliIIII l m||||||9ll|||||||| To all whom t'my concern) j Be it known Ithat I, vANDREW J. BRADLEY, a citizen of .the United States, and a {resii dent of the cityoNeW York and' State ofl New York, have invented a new and usefull Improvement inProcesses of Making Steel' Die-Punches, ofwhich the followingis a specification.

This invention relates to steel dies and:

punches such asare'used in stencil cutting"7 machines, and to the art of 'making' the same and 'comp-rises certain improvements in the dies and processes described i'n my prior Patents Nos. 522953 and 613236.

Punches for stencil machines should have bodies with arallelfwalls exactly conforming to the siiape of their faces. A punch body with parallel walls will not stretch the uncutpaper `surrounding the portions cut out thereby during the punching stroke, as might. occur if the punch body was tapered toward the face of the unch, and also a parallel walled punch wil `not catch under the edges of the hole on the returni strokeas might occur if the punch body was upset or. enlarged upon its face.

Dies for stencil machines should be a i'ew thousandths of an inch larger than the faces of the punches mating therewith, iand moreover, the openingy through the die should be ared or. slightly enlarged toward the bottom of the die in order to provide a clearance for the punched out ieces ofthe stencil and allow themy to all through readily. i

The object of this invention is to produce interchangeable dies and punches having certain advantages hereinafter set Jforth.

A further object is to devise-an improved process of manufacturing said dies which requires no hand ling or upsetting to insure exact conformation and'proper clear-v ance of the cutting edges. This invention consists in the dies and punches, and in theV process of making the same, hereinafter described. i

No. claim is made herein for the diesl and punchesthis part of the. invention being reserved for a separate patent:

In the accompanying drawings, 1n whlch` like characters. are used l to designate the'V same parts in the several views. Figure' lis :"VAND'BEW J. BRADLEY,

PATENT oFFIoE.

ois*l NEwi'Yon'K, N. Y.

l Pnlocnss :on Mammev STEEL Drs-PUNCHES.-

` Specdoationofletters Patent. Patented NOV'. 24,' 1914;.Y .,lnppuogm inea vJuly i4", 191s. sena; No. 778,889;

2 3 in-Fig. 1, looklng in t e direction of' the arrows; Fig. 4 is a plan View of the die blank following the punching operation, showing the side which is uppermost in 'the punching dies; F igs. 5 and .6 are vertical transverse sections through the die blankl shown in Fig. 4, on the lines 5 5 and 6*-6;

r respectively; Fig; 7 Ais a top plan view of the.

die blank reversed to bring 1t into the position in which it is assembled with the punch v plate; Fig, 8 is a vertical transversev section of the same on the line 8-.8 in Fig; 7; Fig. 9 is a top plan view of the punch plate prior to assemblingwith the die blank; Fig. 10 is a vertical transverse section of the same on the linelO-lO'in Fig. 9; Fig. 11 is a y transverse sectional view of the punch-plate superposed upon/ the die-blank priorto the welding operation ;Fig. 12 is a view similar to Fig. 11 showing the punch plate and dieblank after the welding operatlon, but prior to separation of the punchings or counters from the die-blank; Figs. 13' and 14 are transverse sectionalv views of the welded4 punch plate, and the die blankafter separation of the counters therefrom, respectively; Fig. 15 isa bottom plan view of the finished punch; Fig'. 16 is a to plan view of the inished die; and Fig. 1 is a side elevation of the ini'shedlpunch and die, showing the manner in which they are mounted in al stencil cuttngmachine.v

The drawings illustrate `the master dies for shaping, the die-blank and the several stages in the. production therefrom of a stencil. punch and die for cutting the letter G. A full set of master punchesand dies, comprising all the letters of the lalphabet and theusual punctuation marks and characters, together with the numeral figures 2 to 9 inclusive, is necessary to the carrying out of this process.v The dies are made with the character reverse in plan view, as shown in Fig. 1, in which the master die 11 for the letter G. is shown. The master dies also have three holes12 which coperate with 'pins (not shown) removably mounted'in thev i misuse master' punch blocks 13 for punching three tions 15 of the side walls 14 are parallel for about one thirty-second of an inch down from the cutting edges thereof. The master punches 16 are tapered slightly toward the cutting edges, their side walls 17 approaching each other at the rate of about one thirty-second of an inch per inch. The lower portions 18 of the side walls 17 are arallel for about one thirty-second of an inch up from their cutting edges. V

The process followed in making the stencil punches and dies is as follows: A steel die .blank 21, about" three sixteenths of an inch thick, is placed on the master die and the punch brought down until it has penetrated about four fifths through the die blank, which is suilicient to completely sever the punchings 22 from the die blank, but leave them sticking therein. At the same stroke the pins in the master punch lining up with the holes 12 are forced partly through the die blank, but to a slightly less extent than the punchings the lower ends of the pins being set slightly above the face of the punch. The lower ends of the posts 23 which are raised on the under face of the die blank by the pins on the punch block are about one thirty-second of an inch above the lower faces of the punchings 22.

The top edges of the holes punched in the I die blank are left slightly rounded by the punch instead of having absolutely square corners. It is impossible 'to punch soft steel and get absolutely square corners on the top .edges of the punched holes due to the metal surrounding the hole .flowing slightly under the pressure brought upon it by the punch. Heretofore, in making stencil dies by master dies having the character cut upright instead of inverted, it has been necessary to grind off the top surface of the die blank in order to .get square corners for the cutting edges of the stencil die made therefrom. In this process, the bottom of the die blank becomes the top of the stencil die, and the rounded corners made b v the punch are of advantage in providing bottom clearance in the holes additional to that made by the tapered side walls of the punch. For a similar reason to that causing the top edges of the holes to be slightly rounded, the bottom edges of the punchings 22 are slightly rounded. The punchings, however, have parallel walls exactly con` forming in size to the holes in the master die through which they are forced, instead of being tapered like the punch. 'lhe lower edges of the holes in the die-blnnk, on the other hand, are slightly smaller than the holes in the master die, due to slight contraction after the withdrawal of the punch, and grip the punchings tightly.

The die-blank 2l. is turned over, as shown in 7, and a punch plate 24. is placed on it, with the punched out holes 25 fitting the punchings 22. The punch plate is made with the same master dies I11 and 13 with which the die blank was formed, but before punching the lpunclrplate the punch,

pins are removed, and in punching the punch is forced entirely through the plate.

The tapered punch bcvelsthe side walls of the holes 25 slightly. the holes being slightly wider on the side from which the punch approaches. This is the loweil side of the punch plate as shown in Figs. 9 and 10. 'lhe clearance between the rounded edges of the holes in the punch plate and the rounded edges of the punchings 22 is sufficient to enable the two plates to be assembled one on the other as shown in Fig. 11, but not sufficient to leave any appreciable space between the meeting corners, and accordingly the punch plateserves as a ternplet for assisting in maintaining the proper alinement of the punehings during the following operation. The posts 23 serve to position the punch plate parallel with the die-blank, and insure that the depth towhich the pu-nchings project into the holes in the punch plate shall be uniform.

The punch plate and die-blank are clamped in assembled position, and molten steel of the same composition as the punch plate is poured into the cavities in the latter over the punchings 22. This molten steel fuses the punchings to the punch plate and forms a solid punch 26. as shown in Fig. 12. The operation is performed quickly. and the punch plate. and die-blank are so massive in proportion to the molten metal that they are not much distorted by heat transferred to l,them during the operation. More over, if there is slight distortion of the punch plate it does not affect the alinement of the punchings, which are securelyy held by both the punch plate and die-blank- After the partsv cool, the punch plate and punchings are separated from the dieblank, and the surplus metal from the welding operation is planed or ground ofi' from the back of the punch plate. which then appears as shown in Fig. 13.

The die-blank is placed on the master die and lined up by the pins 23. The master punch is forced through the die-blank stencil cutting machine.

fcuie manner.

trim u the cuttin ed s and 've a` slight-.1.- ,ta er opi' relief to te'sf's of tlg; holes, faind ho es 27 are simultaneously punched'for the screws 28 which attach it tothebase plate 29 of the stencil- "cutting lmachine. rI `he edges of the die-blank are trimmed-up,`the screw holes 27 are counter sunk on the to side, and the die-blank is -casehardene forming the nished stencil die 30, as shown in Figs-ie and 17.-

The punch plate is trimmed around its edges and drilled with two holes 3l which are counterbored on the side adjacent the punches for the screws 32 which secure the punch plate to the punch block 33 of the After mounting the punch plate, the punch is forced through the hardened stencil die, which shaves off -the edges of the punch walls to fit the cutting edges of the die exactly. The punch may be left soft, if only paper stencils are to be cut.

It is to be noted that 'the above described process produces punches and dies having sharp cutting edges exactly conforming to each other without hand filing, and without grinding ofr the cutting faces; obviously, the punch portions coperating with the die are exact counterparts of the holes in the latter because both are made with the same master dies. Moreover, as the dies are made from the same master dies as the punches and as a part of the operation of making the punches, the process is cheaper and more rapid than processes wherein separate sets of master dies are used for shaping the punches and dies, respectively.

It is evident that the sizes, shapes and thicknesses of the several parts, and the materials used, may be changed without affecting the process. It is also evident that the die-blank may be punched clear through at the l.first stroke of'the die, and the punchings reinserted therein or assembled in a sepa-rate templet for holding them properlv during theoperation of welding them to the punch plate. Moreover, the punchings may be secured to the punch plateby welding, brazing, soldering, or any other inethod which will unite the parts in a se- This invention is not limited to the exact number or sequence of operations described as constituting the preferred process `of making my improved stencil dies.

What I claim is:

1.* The process of making'stencil character punches which consists in punching a die-blank with a master punch conforming to a stencil character, thereby shearing punchings therefrom corresponding to said character, punching a punch plate with said master punch, inverting and partly-inserting the punchings from said die-blank in acter punches which consists in fpunchin aI die-blank with -a master punch confrinin to ai stencil 'character',fpunc`l`iing"apunc plate with said master'puncli,inverting said punch plate andi-insertingthereinm-the rounded facesof the. punchings fromvsa id die-blank, and' securingV said* piifchln'gstd thepunch plate.

3. The process of making stencil character punches which consists in punching a die-blank with a master punch conforming to a stencil character, thereby producing punchings having rounded lower faces, punching a punch plate with said master punch, the upper edges of the openings in said punch plate having rounded edges, inserting said punchings in the openings in said punch plate with the rounded edges toward' each other, and securing said punchings to said punch plate..

4. The process of making stencil character punches which consists in punching a die-blank with a master punch conforming to a stencil character, thereby producing punchings having rounded lower faces,

punching a punch plate with said master punch, the upper edges of the openings in said punch plate having rounded edges, inserting said punchings in the openings-.in

said punch plate with the rounded edges toward each other, and securing said punchings to said punch plate while holding said punchings in a templet on the side opposite said punch plate.

5. The process of making stencil; character punches which consists in punching al die-blank with a .master punch having a' body which tapers toward its cutting edges, said body and cutting edges conforming in outline to a stencilv character, thereby producing punchings, punching a punch plate with said master punch, inserting said punchings in the wider ends of the openings in said punch plate, and securing said punchings to said punch plate.

6. The process of forming mating punches sharp cutting edges u@ Lumen a punch plate with said master unch, inhardened die-blank, thereby formingsherp serting the projecting faces or' t e punchcutting edges on said punch and die. lo ings in said die-blank into the openings in Signed at the city of New York, N. Y., said punch plate, securing said punchings to this 9th dey of July, 1913.

said punch plate, removing the punchings ANDREW J. BRADLEY.

from said die-blank and forcing seidmaster Witnesses: v punch through it, hardening said de-b1ank, FRANK J. DUFFY,

and forcing said punchings through said MARTHA NOMMENSON.