US295227A

US295227A - Edwaed w

Info

Publication number: US295227A
Authority: US
Publication date: 1884-03-18
Anticipated expiration: 1901-03-18

Description

(No Model.) Y

B. W BRIGGS 82: J. D. WALTON.

PUNCH. N0. 295,227. Patented Mar. 18, 1884.

Wit. msse s iiiurrrio Sterne Parent @rrrcsl EDWVARDW'. BRIGGS, Oh BROOKLYN, AND JOHN DuWALTON, OF NEYV YonK, n; Y.

PUNCH.

SPECIFIGA'IIQN forming part of Letters Patent No. 295,227, dated March 18, 1884.

ness, may be operated with less power, lessliar bility to crack or injure the material, and departure from the size and shape of the punch than has been found practicablewith punches of the ordinary kind and character, and also one which wilhitself belessliableto injuryin other words, more durable when subjected to the stress of actual use under severe conditions.

For this purpose punches have been made with a supplemental cuttingshoulder produced by reducing the diameter of what would 2 otherwise be the acting end of the punch by turning the same down to form a sharp circumferential edge on the fiat face of a perfectly-cylindrical shoulder, the object being to remove the metal by cooperating successive- 3o cutting actions of the cuttingedges of a single punch, whereby tov avoid the ragged surface or edge produced by the tearing action of a punch having a single face cutting-edge. In such construction, the face of the cutting-edge 5 of greatest diameter joins the cylindrical surface of the cutting-edge of least diameter with a sharp angle, so that the action of bothcutting-edges upon the metal-is alike. Punches have also been made with a cylindrical body 0 surrounded by aseeond cutting-edge of undulating or scalloped form, so that in reaming the metal around thepunched hole the shearing thereof will be borne equally by the downward projections otsaid second cutting-edge. 5 Our improvement comprises a punch having successive punching-edges formed on fiat faces of unequal diameter,and joining each other by an outwardly inclined or curved wall, in order that the cutting-edge of least diameter will operate not only to remove the central por- Application filed March 30, 1883. (No model.)

tion of the material from the space to be punched, but also operate to bend the remaining portion of the metal to be removed, and thereby to crack and break away the hard scale from the surface of such remaining portion of the metal, and thus expose the soft or unsealed surface to the action of the succeeding cuttingedge, which determines the size of the hole, and which is thereby caused to cut with much less resistance and to produce asmoother edge around the hole. In this important particular the first acting cutting-edge of least diameter operates in a different manner from the finishing cutting-edge, and gives an advantage not hitherto attained by punches having successi ve cuttingedges. A conical projection is formed upon the face of the cutting part of least diameter, and its relation to such cuttingedge is such as to bend the metal before re ceiving the action of said cutting-edge, so as 7a to break thescale and render the cutting easier, while at the same time such projection serves the function of the center holding-point common in punches for punching metal.

' Figure 1 is aside view of a punch en1bracing one portion of my said invention. Eig. 2 is aside view; Fig. 3, a longitudinal sectional View, and Fig. 4 a face view, of apunch, embracing' also an additional feature of my said invention.

A isthe cylindrical body of the punch, which said body need not dili'er materially from that of punches in common use, and is provided with or constructed for the use of any suitable means of attaching it to the movablehead 8 5 of a punchingpress. It is of conrse'to be understood that the punch is to be used in connection with a suitable bench or support for holding the material to be punched, and furnished with a suitable die for acting in con- 0, junction with the punch during the operation of the latter. As this support, die, the, may be of any ordinary kind or character and designed to act in the ordinary manner in relation to the punch, such support, die, 850., need 5 not be here specifically described. The face, however, of the punch is of novel construction, being provided with successive puncl1- ing-edgest\vo or more, joined by a curved wall which act in succession upon the ma- 10o terial to be punched. so that the latter offers less resistance at any one moment of time during the operation of punching than is possible where a single cu tting-edge is required to at once part the material around the whole circumference of the holeor opening to be made. Furthermore, the punch constructed according to my said invention, with the curved wall intervening bet-ween the cutting-edges,

when operating on iron, rolled steel, and the like,loosensthe scale upon'the surfaceofthematerial and causes the same to chip or scale off, leaving the naked and comparatively soft metal exposed to the action of the larger or circumferential cutting-edge of the punch, thereby greatly lessening the power required to drive the said edge through the material.

As represented in Fig. 1, the face of the punch is formed with a central projecting portion of less diameter than the face of the punch itself, this portion having a cutting-edge, a, which should be substantially concentric with the circumferential cutting-edge b of the punch, and join it by a curved wall, 6, as shown. WVhen the punch is forced against the material to be punched, the edge a acts first, and not only removes a central portion of the material from the space to be punched, but also cracks and breaks away the hard scale from the surrounding portions. The cutter, being deprived of support from the central portion, now removed, of the material, and also exposing its naked or unsealed surface, affords much less resistance to the succeeding action of the edge I), which determines the size of the hole.

Furthermore, owin to this diminished resistenlargement does not exceed one-eighthof an inch. advantageous operation of my said invention, I provide atthe center of the part A a projecting conical teat or projection, c, which, by bending the material into a conical cavity at the center of the part to be punched out, bends said material at such portions into such position thatitmay be mostadvantageously sheared by the successive action of the edges a and b. When desired, the face of the punch may be provided with more than one additional cut-' ting-edge a, arranged within its circumferential cutting-edge b.

It will be seen that the conical projection c not only serves the purpose of the holdingpoint common in flat-faced punches, but has such relation to the cutting-edges of least diameter as to prepare the metal to receive the first out by bending it into a conical cavity at the center part to be punched, and thus serve to break the surface scale and rendtrcessive annular punching-edges a 12, joined byan outwardly inclined or curved wall, e, as described, for the purpose set forth.

2. The metal-punch herein shown and described, having the successive annular punching-edges a 12, joined by a curved wall, 6, and a cone projection, 0, having the described re- In order to obtain, however, the most lation to the cutting-edge of least diameter,

for the purposes specified.

EDWVARD W. BRIGGS. JOHN D. WVALTON.

Witnesses:

RUDoLF H. BJELLMAN, EDWARD A. HoLLEY.