Year: 1886

page_text: I, ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Engineer do hereby declare the nature of invention (a coinmunication from
James Brady residing at Brooklyn New York United States of America) and in
what manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:—
This invention applies more especially to the formation of small dies to act in
conjunction with corresponding punches for small letters or figures such as used in
check punches and cancelling machines for perforating the papers with figures or
letters. In this case it is desirable to make the dies of thin sheet steel and cheap-
ness and accuracy of construction or imperative so that my invention aims to form
the die in a manner which will produce the cutting aperture therein in a rapid
exact manner and at the same time insure the metal being dense and strong at the
cutting edges of the aperture. To this and the main feature of my invention may
be stated to in forming the aperture of the die entirely by successive operations of
punching and drifting with punches and drifts of a form corresponding to the said
aperture and the invention further lies in the special nature order and combination
of the punching and drifting operations as hereinafter fully set forth.
The drawings annexed give sectional and plan views of the dies and the tools
used in forming the same from the first to the last stage of the process.
Figure 1 represents the die-blank.
Figure 2 represents the first punching operation thereon.
Figure 3 represents the die after this first operation.
Figure 4 represents the second operation and Figure 5 shows the die after this
operation.
Figure 6 shows a section of the die after the third or face grinding operation.
Figure 7 represents the fourth or flaring operation, and Figure 8 gives a section
of the die after said operation.
Figure 9 represents the fifth or drifting operation, and Figure 10 gives a section
of the finished die. The figures are, however, shown exaggerated in size for better
illustration.
ย
The blank from which the die is to be formed in indicated by a and is shown in
Plan and section in Figure 1.
اری
1.
3
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page_text: It is preferably a round disc of thin sheet steel about one inch in diameter and
one sixteenth of an inch thick, but of course the exact material or size of the disc
or die is not an essential point to specify. The disc a being of course in an
annealed state is first placed on a die-block b as seen in Figure 2 over an aperture c
therein of form corresponding to-but a little smaller than the desired character
to be produced in the finished die, and under a punch d of corresponding form in
line with the aperture in the die block 6 below it. The punch d is then depressed
by the action of a suitable die-press, and the punch is thus forced through the die-
blank a thereby cutting therein an aperture of a form corresponding to the
character desired as shown in Figure 3 which in this case is the numeral 3 thé
aperture or numeral being however a little smaller than that in the finished die.
The above described operation forms what may be called the first stage of the
process and in this operation it is to be noted that the die-blank a is punched from
the upper side that is the side which in the finished die is to be the cutting side in
which the punch enters to perforate the paper placed between the two. It will be
readily understood therefore that when the die blank is thus punched from its
upper side that the edges of the character aperture ƒ will be rounding, as illustrated
in the section in Figure 3 from the bending and drawing in of the metal with the
punch. Hence the die if finished after this punching would have a dull round
edge on the character aperture whereas it is necessary that it be angular and sharp.
In order therefore to neutralize this rounding effect of the first punching the
operations illustrated in Figures 4, 5 and 6, which compose stages 2 and 3 are
resorted to. In the second stage as shown in Figure 4 the punched blank a is
placed upside down on an anvil block g over a slightly rounding and circular
depression h therein of a size which will a little more than circumsribe the
character aperture. A swaging punch i arranged above the block g and having its
end of form similar to the depression h and in line therewith is then forced down
on the punched blank a and the upper side of the die is therefore bulged up
slightly around the character aperture on the upper side as fully shown in
Figure 5. This bulge raises the rounding edges of the character aperture slightly
above the general surface of the blank and this raised part is in the next or third
stage ground, filed or milled off to a level with the rest of the die as seen in
Figure 6 which as will be seen will cause the character aperture to have sharp
angular edges at the top of the die.
'
It may now be argued that if the die blank was in the first stage punched from
the underside that the rounding edges referred to would then be on the under side
of the die where they would be unobjectionable and hence the bulging and
grinding operations of the 2nd and 3rd stages might be dispensed with. This how-
ever is readily answered as follows: That is when the die is thus punched from
the underside the edges of the character aperture at the top, are, it is true, left
comparatively angular and sharp yet I find that the metal at the edge is also
disintegrated and left in a comparatively weak and granular state which prevents
the die taking a good cutting edge and causes the edge to rapidly break down or
crumble off as soon as it is hardened and used. On the contrary when the die is
punched from the top side and then bulged from the under side and ground off on
the top as described, not only is the edge of the character aperture made very sharp
but the metal is found to be exceedingly compact and tough and the edges thus
rendered very strong keen and durable.
The above described operations being completed the die-blank is in the 'next or
fifth stage placed upside down on a level anvil block k of hardened steel as shown
in Figure 7 and a punch or swage 1 of a form corresponding to the character
aperture of the die but with a widely tapering shape is then forced into the
aperture of the die to about half its depth which will thus leave the lower part of
the character aperture flaring or tapering outwards as shown in section in
Figure 7 as is necessary for the usual back clearance or "freeing" usual in dies.
This freeing operation as above described and shown in Figure 7 will not in any
way injure the cutting edge of the character aperture for as the right side of the
"

page_text: die is placed flatly on a solid anvil-plate and the tapering punch is forced in from
the back side of the die the effect of this operation will be in fact to still further
solidify and improve the texture of the metal towards the cutting edge of the
aperture which is of great advantage to the die and an important result of this
operation.
After the freeing operation above described the die is next placed upside down
on a die-block m similar to the first die-block b but having a character aperture n
slightly larger than the finished size with which the aperture in the die-blank a is
registered. A drift or punch p works above the die-plate m in line with its
aperture n which drift or punch has a very long gradual taper of a size at the tip
slightly smaller than the character aperture in the die-blank as cut by the first
punch d in Figure 2 and of a size and form or section at or near the root of the taper
corresponding to the finished aperture desired. This drift or punch is then slowly
forced through the die-blank so as to gradually widen out the character aperture
to its finished size making it at the same time slightly flaring toward the wide flare
in the under part of the aperture and gradually compressing and smoothing, the
metal toward the cutting edge of the aperture and imparting a hard glaze and
polish to the walls of the aperture as will be readily appreciated which greatly
improves the metal at the cutting surface of the die and enables a cutting edge of
unusual strength and keenness to be maintained thereon.
As soon as the die is removed from the tapering and finishing punch or drift in
Figure 9 it is then hardened preferably case hardened so that the hardening is
confined to the surface of the die while the centre is left soft for strength and after
the hardening the upper surface is ground off slightly by a very fine emery wheel
or its equivalent which will render the cutting edge of the aperture very keen
which operation finishes the die so far as this invention is concerned.
It may now be readily observed that all the successive operations described tend
to strengthen the metal toward the tip of the die and at the cutting edges of its
character aperture and instead of straining the metal or displacing the particles
thereof all the steps tend to compress. and harden the metal and render it very
dense tough and smooth and thus admirably adapted to take and retain the cutting
edge necessary in an effective and durable die. It will be further seen that all the
operations are done by special tools and are the simple ones, of punching swaging
drifting and grinding which can be done rapidly by inexpensive labor which
enables the manufacture of the dies to be not only rendered very accurate but also
very cheap which latter is an essential for many purposes where such dies are used
in large numbers.
Heretofore dies of this character have been made by the slow and difficult
operations of drilling and filing which is so expensive as to practically prohibit
their use for many purposes whereas by my system the coat is reduced to cents as
compared to dollars for the old system.
It will be understood that where it is specified grinding, grinding with emery
wheels is considered preferable but filing or other abrading operation will be the
equivalent thereof.
"It will be also understood that it will not be necessary in all cases to employ all
the operations described nor in the exact order stated and this invention is not
confined thereto.
Having now particularly described and ascertained the nature of this said
invention and in what manner the same is to be performed as communicated to
me by my foreign correspondent I declare that what I claim is.
1. The method of making character or figure dies the same consisting in first
perforating the die plate with a punch of a form coresponding to the desired
character then hardening and finishing said die by a series of punches corre-
sponding in form to the shape of the aperture substantially as and for the purpose
set forth.

page_text: 2. The herein described process of die-making consisting in first perforating the
die blank with a punch of the form corresponding to the desired character forced
through from the top or right side of the blank then denting the blank on the
reverse side and bulging it up around the character aperture on the right side and
subsequently grinding off the said bulge substantially as and for the purpose set
forth.
'
3. A method of die-making combining the following operations; first punching
the die blank from the upper or right side with a punch having a form corre-
sponding to the desired character and thus forming an aperture corresponding to
said character; secondly, denting or swaging the blank on the reverse side and
thereby bulging the die on the right side around the character aperture; third,
grinding or cutting off the said bulge and finally enlarging the aperture to its
finished size by compressing the walls thereof by means of a long gradually
tapering drift or punch of section similar to the first forced through the said
aperture substantially as and for the purpose set forth.
4. A method of die making combining the following operations: first perforating
the die with the desired character aperture by a punch forced through from the top
or right side; bulging the die around the said aperture on the top side; grinding
or cutting off the bulge; flaring or freeing the character aperture on the underside
by a widely tapering punch or swage forced partly through the same, and finally
enlarging the aperture to its finished size by a long gradually tapering drift or
punch forced through the same so as to compress, smooth, and toughen, the metal
at the cutting edges of the aperture substantially as herein set forth.
5. A letter or figure die perforated with an aperture corresponding to the desired
character; said aperture being cut in the blank freed or tapered on its back side
and compressed to the finished size entirely by the action of successive punches
Bwages and drifts, of form corresponding to the said character aperture substantially
as herein shown and described.