Improvements in or connected with Draw Plates.
Year: 1896

page_text: COMPLETE SPECIFICATION.
Improvements in or connected with Draw Plates.
We, WILLIAM ALLEN MCCOOL and WILLIAM GIBSON ALGEO, Junior, both of
Beaver Falls, in the State of Pennsylvania, United States of America, Mechanical
Engineers, do hereby declare the nature of this invention, and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
The object of the invention is to produce a die which may be used for fine work
where almost absolute accuracy of size is needed, and which may be adjusted
to take up or compensate for any wear or enlargement of the die, without in any
way sacrificing the rigidity of the die as held in the die block or holder, and
without necessitating a re-cutting of the mouth or throat of the die.
The nature of the invention will be clearly understood from a description of
the accompanying drawings. In these drawings,
Fig. 1 is a face view of the die block holding a form of die designed for drawing
bars from which the links of bicycle chains may be cut.
Fig. 2 is a central section of same, showing also a portion of the die head of
the drawing machine and the manner of holding the die block or holder.
Fig. 3 is a face view of the die block with the die and keys removed.
Fig. 4 is a cross-section on plane 4-4 of Fig. 3.
Fig. 5 is a cross section on plane 5-5 of Fig. 3.
Fig. 6 is a face view of the divisible die itself.
Fig. 7 is a side or edge view thereof.
Fig. 8 is a cross section on plane 8--8 of Figs. 6 & 9.
Fig. 9 shows one of the parts or members of the divided die.
Figs. 10 and 11 are edge view and convex face view of one of the keys, and
Fig. 12 is a cross section of the key on the plane 12-12 of Figs. 10 and 11.
Briefly stated, the invention is as follows: In the case of a sprocket chain link
for bicycles, and in other instances where it is essential to keep the length of
the link or object to be made accurately the same, it is necessary to compensate
for the wearing away of the die by the repeated drawing of the bars through it.
We accomplish this by splitting the die transversely to the line or dimension of
the bar which must be kept accurately gauged; and when a sensible enlargement
of the die has taken place, we remove the die from the die holder and plane off
from one or both of the meeting faces of the two parts of the die enough metal
to exactly compensate for the wear and elongation of the die. The die is then
When so cut
replaced in the die block or die holder and the keys driven in.
away and restored to the original dimensions, the die may be used until it has
been again appreciably enlarged, when the process may be repeated. It is clear
that as the die is composed of but two parts having two plane faces pressed
rigidly together, neither the strength nor the rigidity of the die is in any manner
sacrificed.
In the figures, D illustrates the die or draw plate; H the die block or holder,
L the die head of the drawing machine in which the die block may be driven,
and K and K¹ the two keys. The die is divided on the plane d into two members,

page_text: as shown, and these are forced rigidly together and held in place by the key K.
The key K¹ confines the die transversely between the plane face k of the key
and the opposing face of the die holder, so that absolute alignment of the two
parts of the die is always secured. When the die has worn away or enlarged
an appreciable amount, say one-thousandth of an inch, it is taken from the
holder and the plane face at the dividing plane d of one of the dies is planed off
one one-thousandth of an inch or both dies are planed down one two-thousandth of
an inch. The dies are then placed back in position and the wedge keys driven in,
whereupon the increased length of the die due to the wearing away will be
accurately compensated for.
We construct the two keys K and K₁ of the cross section shown, so that they will
present on one side a plane face, and on the other a slightly tapered off cylinder
or cone. This form of key when placed in a correspondingly shaped seat is free
to turn and adjust itself so that the plane face will lie absolutely parallel with
and against the face of the die and insure greater accuracy and more even dis-
tribution of the confining pressure which holds the die in place.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is:
1. In combination with a die holder, a draw plate or die therein consisting
of two parts separable upon and in contact at a line or plane d which divides or
cuts the throat of the die, means bearing upon the said two parts in the said plane
of separation for forcing the said two parts into accurate alignment, and means
forcing the two said parts rigidly together, whereby the said die may be rigidly
secured in accurate alignment and constitute when in use a substantially integral
draw plate or die, substantially as set forth.
2. In combination with a die holder, the draw plate or die D mounted therein
and consisting of two parts, separable at the line or surface d which divides or
cuts the throat of the die transversely, and the keys K K¹ of the semi-conical
or semi-circular cross section, one key forcing the two separable portions of the
die together and the other key bearing upon both portions of the die equally and
aligned them, substantially as set forth.
Dated this 15th day of September 189
J. G. LORRAIN, M.I.E.E., M.I. Mech. E.,
Norfolk House, Norfolk Street, Strand, London, W.C.,
Chartered Patent Agent.