Improvements in Punches and Dies.
Year: 1890

page_text: Date of Application, 23rd Dec., 1890-Accepted, 31st Jan., 1891
COMPLETE SPECIFICATION:
Improvements in Punches and Dies.
I FRANKLIN BENJAMIN BRISTOL of Naugatuck Road Waterbury in the County
of New Haven and State of Connecticut in the United States of America Machinist
do hereby declare the nature of the said invention and in what manner the same is
to be performed to be particularly described and ascertained in and by the following
statement :-
My invention has reference to improvements in punches and dies for cutting
sheet metal blanks and especially to punches and dies for cutting out annular or
serrated blanks for belt fasteners and the like. It consists essentially in a punch
or a die, formed of a number of separate sections joined together by any suitable
means, each section being provided with cutting edges tapering uniformly to a point,
the combined sections forming a continuous angular or serrated cutting edge. By
this improved construction I am enabled to obtain sharp clean angles at the bases
of the tapering cutting edges and furthermore in case of breakage or abrasion of
any one of the sections, the substitution of another section involves but a slight
expense and requires a short period of time only, while at the same time the blanks
can be successively punched out without waste.
In the accompanying drawings:
Figure 1. represents a plan view of a punch constructed according to my
invention.
Figure 2. is a similar view of a die.
Figure 3. is a sectional elevation showing the punch and die in their relative
operative positions.
Figure 4. is a perspective view of a punch (or die) detached from the jaw,
or bed.
Figure 5. is a face view of a blank as cut by the punch and die.
Figure 6. is a similar view of the sheet metal stock from which the blank is cut.
Similar letters indicate corresponding parts.
In these drawings the letter A designates a punch composed of a number of
sections a joined together, side by side, by any suitable means, for instance by a
bolt B passing through the sections and a nut b, in conjunction with which latter a
lock nut may be used.
Each section is provided with cutting edges a¹, tapering uniformly to a point,
consequently the combined sections will present a continuous angular or serrated
cutting edge. It will be seen that in virtue of this construction the inner angles a²,
formed between the several sections a, can be made as acute or sharp as may be
desired by giving to the sides the necessary taper, and that any section when broken
or worn can be readily removed and another substituted or the length of the punch
can be altered at will. The punch thus formed can be secured in a jaw or chuck,
as C, (Figures 1 and 3), by any suitable means for instance by the key D. Suitable
blocks as may be used to fill up the jaw or chuck in case the punch is not
wide enough to fit the chuck; the bolt B in this case passing through the
blocks also.
The construction of the die A' is similar to that of the punch and it is similarly
fitted to the bed C¹ of the machine.
The exterior and interior edges of the punch and die are properly bevelled for
clearance and the upper face of the die may be inclined to produce a shearing action
on the stock fed between it and the die.
In Figure 5 I have shown a blank for a belt fastener as cut by the punch and

page_text: die, for which purpose I have found the latter especially useful; Figure 6 illustrates
the stock after each stroke of the punch.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed I declare that what I
claim is
A punch or die for cutting belt fastener blanks composed of a number of sections
each provided with cutting edges tapering uniformly to a point, said sections being
joined together by means such as the bolt B, to forin a continuous serrated cutting
edge, substantially as described.
Dated-this. Zord day of December 1030.
F. B. BRISTOL.
By Harris & Mills,
23, Southampton Buildings, London, W.C., Agents.