US2175139A

US2175139A - Method of making punches and dies

Info

Publication number: US2175139A
Application number: US255893A
Authority: US
Inventors: Robert J Wilkie
Original assignee: CONTINENTAL MACHINE SPECIALTIE
Current assignee: CONTINENTAL MACHINE SPECIALTIE; CONTINENTAL MACHINE SPECIALTIES Inc
Priority date: 1939-02-11
Filing date: 1939-02-11
Publication date: 1939-10-03
Anticipated expiration: 1956-10-03

Description

R. J. WILKIE METHOD OF MAKING PUNCHES AND DIES Filed Feb. 11, 1939 Patented Clot. 3, 1939 anz'rnon or MAKING PUNCHES AND mus Robert J. Wilkie, Minneapolis, Minn, assignor to Continental Machine Specialties, Inc., Minneapolis, Minn., a corporation of Application Februaryll, 1939, Serial No. 255,893

7 Claims.

This invention relates to the art of making dies and refers particularly to a method of making cutting and punching dies.

In the past, the matrix or die proper generally has been cut from a piece or blank of stock directly to or very close tothe outline of the die layout line; and in the ordinary machining processes used for this purpose, the part out out, which is sometimes called the slug, was either reduced to chips or otherwise'rendered unfit for use. This resulted in considerable waste inasmuch as the punch for the die had to be cut separately out of another piece of stock and very carefully machined to fit the die proper.

This past method of making a set of dies (punch and matrix) was also objectionable due to the excessive expenditure of labor necessary to properly cut and fit the parts. v

This invention, therefore, has as one of its so objects the provision of an improved method of making dies whereby the slug, which is the material cut from the blank in the roughing out of the die proper, may be used to make the punch,

thereby effecting a considerable saving in time .and material, as a single cutting operation roughs out the punch as well as the die proper from a 1: single piece of material no larger t that *quired for the die pr *More specifically, this invention contemplates simultaneously cutting the punch and die from a .sing'le'blank of material in such a manner that an excess of material -sufficient for properly finishing the edges of the punch and the die is left on both pieces. p p

" This invention also contemplates a method of cutting'th'e stripper for the punch simultaneously with the cutting of the punch and the die. 3

With the above and other objects in view which will appear asthe'des'cription proceeds, this invention resides in'the novel construction, combinationand arr'angement'of parts substantially as hereinafter described and more particularly" defined by the appended claims, itibe'ing understood that such changes in .theprecise embodiment of the hereindisclo'sed .invention may be made as come within thescope of the claims.

. The accompanying drawing; illustrates two complete examples of the physical embodiment of 5 the invention constructed according to thebest modes so far devised for the practicaluapplication of the principles thereof, and in which:

Figure 1 is a perspective view partially in section, showing the manner in which the cut is a made;

die and punch made in accordance with the meth od of this invention; Y

Figure 3 is a perspective view showing the punch and die directlyafter the roughing operation with the slug (from which the punch ismade) removed from the die; and

Figure 2 is a vertical sectional view through a Figure 4 is a vertical sectional view illustrating a method of cutting a stripper-plate simultaneously with the cutting of the die.

Referring now more particularly to the accompanying drawing, inwhich like numerals indicate like parts, the numeral 5 represents a block or blank of stock'of a size sufficiently large to be used as the matrix or die proper. In order to cut the die so that the slug may be used as a punch, a hole 8 is first drilled through the thickness of the block at an angle to an axis normal to the general plane of the block. The angle at which the hole is drilled is sufllcient to dispose the edge of the hole at the top v face 1 of the block inside the die layout line 8 I and the edge of the, hole at the bottom face 9 of theblock outside the die layout line. The thickness of the stock thus determines the angle at which the hole is drilled and also the diameter of the hole, it being desirable to keep the hole as small as'possible. I I

After the hole has been drilled, a saw blade I ll is inserted through the hole. Any suitable type of power saw may beemployed; although it is preferable to use a band saw (not. shown) in which case the blade must be cut and welded.

The table of the saw, representedby the line "1', is tilted so that the saw blade passes through and substantially bisects the irregular plane conline at the'bottom'face 0 of'the block. The s des of the hole I I and of theslug l2 arefconsequently tapered, providing an excessof material I! extending inside the die layoutline at the top face of the die, and an excess of material it at the'bottom of the slug i2 extending outside the die layoutline." a

After cutting, the slug i2 is removedas clearly illustrated in Figure 3. The edge ofthehole in the .matrix or dieproperfwhichjhasfthe excess material I! overhanging the die layout line, is then accurately filed or'trimmed down to the to form the "land".

layout line perpendicularly to the face of the die The slug I2 is transformed into the punch by centering the die on the larger face of the slug and inscribing its contour thereon. The edge portion l4 outside the line thus obtained is then cut or filed off to form the straight side of the punch.

During the removal of the excess stock from the edge of the hole II and the edge of the slug, the starting hole disappears from the straight side of the punch and the "land" on the die proper.

It is particularly significant that the slug or punch and the die proper are cut simultaneously from a solid block. This assures greater strength as the grain of the stock may be matched after finishing the punch and die.

While it may be more feasible in most instances to use a saw for making the cut, it is understood that a cutting torch may be used, if desired. In this event, it is, of course, unnecessary to drill a starting hole.

If the shape of the punch and the die and the nature of the material to be punched is such that a stripper is required, it may be produced simultaneously with the roughing out of the punch and die. To this end, a plate i5 is secured to one side of the block 5, as shown in Figure 4.

A hole will then be cut in this plate to a shape corresponding with that of the die layout line but sufliciently large to provide clearance for the punch.

From the foregoing description taken in connection with the accompanying drawing, it will be readily apparent to those skilled in the art,

' that this method of making a die is particularly well suited wherever the outline of the die is irregular and that a substantial saving in material and time is efi'ected thereby.

What I claim as my invention is:

l. The herein described method of roughing out a punch and die from a single piece of stock and in such a manner that the roughed out punch and die both have an excess of stock overhanging the die layout line, which comprises: forming a starting hole through a blank at an angle to an axis normal to the face of the blank and with the edge of the hole at one face of the blank inside the die layout line and the edge of the hole at the opposite face of the blank outside the die layout line; inserting a saw blade through said hole; and sawing through the blank at an angle to said axis with the saw-cut following the die layout lineffand extending inside the boundary defined by the die layout line at one face of the blank, and outside said boundary at the opposite face of the blank-the .angle of sawing being different than that of the starting hole whereby the hole is substantially eliminated at opposite sides during the sawing.

punch and the die so that the punch slugis movable through the hole in the'die blank, said removal being such as to'provide the punch and the die with clearance.

punch and die which comprises: drilling a hole through a die blank at an angle to an axis normal to the general plane. of the blank; inserting a saw blade through said hole; cutting a punch slug from the blank by sawing at an angle to said axis and in such relation to the die layout line that the surfaces of the cut taper to provide an excess of material overhanging the die layout line at one face of the die and at one face of the punch slug; and removing said excess material so that the punch slug is movable through the hole in the die blank.

4. The herein described method of making the male and female parts of a die which comprises: cutting a piece from a blank of material to substantially the size and shape of the male part of the die and with the cut disposed at an angle to the face of the blank so that the perimeter of the piece at one of its surfaces is sufliciently larger than its perimeter at its opposite surface to preclude passage of the piece through the hole in the blank; and accurately removing part of the side walls of the piece and the hole to fit the piece to the hole for smooth passage therethrough with the proper clearance for a punch and die.

5. The herein described method of making a punch and die which comprises: cutting through a blank which is to form the die substantially along but spaced from the die layout line and at an angle to an axis normal to the face of the blank so that the area defined by the cut and coinciding in size and shape with the area defined by the die layout line lies on a plane between the faces of the blank and an excess of stock overhangs the die layout line at one face of the piece thus cut from the blank and at one face of the blank; and removing said excess stock from both the blank and the piece to make the piece movable through the hole in the blank.

' 6. The herein described method of making a punch and die and a stripper for the punch which comprises: removably securing a stripper blank to one side of a die blank; and simultaneously'cutting a hole through said blanks with the surface of the cut tapered and the largest end of the hole in the stripper blank, and withthe cut so related to the die layout line as to provide an excess of stock overhanging the die layout line at one face of the die and at one face of the punch slug cut from the die blank and so that the hole in the stripper blank is larger than the punch slug cut from the die blank.

7. The herein described method of making a punch and die which comprises: drilling a hole, through a die blank at an angle to an axis normal to the general plane of the blank; inserting a saw blade through said hole; cutting a punch slug from the blank by sawing at an angle to said axis less than the angle at which the hole is drilled and in such relation to the die layout line that the surfaces of the cut taper to provide an excess of material overhanging the die layout line at one face of the die and at one face of the punch slug; and removing said excess material so that the punch slug is movable through the-hole in the die blank, the diiference in angularity between the drilled hole and the saw cut being sufllcient to insure cutting away the drilled hole at the cutting faces of the punch j sing and die blank during the removal of said "excess material. 3. The herein described method of maki a ROBERT J. WILKIE.