Improvements in or connected with Draw Plates.
Year: 1896

page_text: Date of Application, 15th Sept., 1896-Accepted, 15th Sept., 1897
COMPLETE SPECIFICATION.
Improvements in or connected with Draw Plates.
We, WILLIAM ALLEN McCooL and WILLIAM GIBSON ALGEO, Junior, both of
Beaver Falls, 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 procure 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 recutting of the mouth or throat of the die.
Our invention consists of the process or method by which the wear of the lie is
compensated for, and, in addition, our invention includes the apparatus, con-
structed, arranged, combined and used substantially in the manner hereinafter
described, illustrated and claimed.
The nature of the invention will be clearly understood from the description
of the accompanying drawings, wherein
Fig. 1 is a face view of the draw plate or die secured in position in the die
block or holder, but with the annular screw cap (Fig. 2) removed.
Fig. 2 is a cross section on the plane 2-2 of Fig. 1, but showing the screw cap
in position.
Fig. 3 is a plan view of the screw cap.
Fig. 4 is a face view of one of the die sectors.
Fig. 5 is an edge view, and
Fig. 6 shows one of the blanks or plates from which the dies are formed.
Throughout the drawings like letters of reference indicate like parts.
If six equilatered triangles are placed together around a common point they
will, as is well known, form a perfect hexagon. And if any one of these six
triangles is diminished by cutting a layer from any one side, or from all three
sides of it, it may still be fitted into its place without disturbing the others.
Following out this principle, we have devised a hexagonal die for drawing
hexagonal bars, and a process for compensating for the wear and consequent
enlargement of the die surfaces.
Fig. 6 shows in face view a plate or blank in the form of an equilatered triangle
from which our dies are formed. Figures 4 and 5 show the completed sector or
member of our draw plate or die. The complete die is shown in Figs. 1 and 2.
It will be seen that six of these triangular sectors are placed together with the die
faces a placed to form the hexagonal throat or mouth. The curved or flaring
form of these die faces, a, is clearly shown in Fig. 5. The dies are pressed firmly
together by means of the six screws, S, set around the die block or die holder H.
This holder is recessed to receive the dies, as shown in the cross section Fig. 2,
and the screw cap, C, threaded in the holder H, retains the dies in place so that
they may be acted upon by the screws S. By means of these screws, the dies I)
may be adjusted so that the die faces, a, form a perfect hexagon. The two other

page_text: corners of each die are cut to form smaller or larger dies, b, c, so that each of
the dies may be taken out and turned 120 degrees to form a different die of
greater or less diameter as desired. The meeting surfaces f at the sides of the dies,
and which give to each die the form of a perfect equilateral triangle before the
die faces a,, c are cut, enable the six members of the die to fit together equally
well for all three sizes of die. When one of the dies has been in use for a con-
siderable time and has been appreciably worn away and enlarged, the dies are
taken out of the holder, and one of the surfaces f of each sector or member is
carefully planed off so that when the dies are replaced the worn faces a will again
form a hexagon of the correct size without requiring any recutting of these sur-
faces a; for instance, if the diameter of the throat or mouth of the die has been
enlarged two one-thousandths of an inch, and it is desired to correct this, one
one-thousandth of an inch may be cut away from one of the meeting surfaces
of each member of the die, which will cause a reduction of two one-thousandths
in the diameter of the hexagon.
If the surface f, which is numbered in Fig. 1, is cut away from each die,
it is clear that it will allow the die faces a to come closer together in the manner
just described and reduce the size of the throat or mouth formed by these faces a.
But is is apparent that since the surfaces 2 and 3 are untouched, the die face c
between these two surfaces will be in no way affected, and the size of the hexagonal
throat, which these faces care adapted to form, will not be altered in size. It
is therefore clear that with the triangular form of sector which we have shown,
two die faces may he cut on each sector, and either of these may be adjusted by
plaring off the side of the sector to compensate for wear, without in any way
affecting the die face. It is also clear that with the triangular form of die sector
shown there will always be presented to the screws S a perpendicular bearing
face and the screws S will therefor always act properly in compressing the dies.
and forcing them rigidly into proper adjustment.
In its broader aspect the invention may be applied to dies divided into four,
eight, or other number of sections or sectors, but when this is the case the dies
will not be reversible, in the same manner, but a single die face can be formed on
each sector. However, the same process of cutting away and adjusting to
compensate for wear may be employed with the same results as described above.
In employing the term "sector" to describe our die members, we have used
the word in its obvious analogy to the sector of a circle, and we mean thereby
a part or number having sides which lie in two planes f inclined to each other
and both cutting the throat of the die. The word "sector" is used to succinctly
express this relation. It is the angle or point produced by the meeting of these
inclined sides that is cut away to form the throat a of the die.
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 in a draw plate or die, die members fitted together and each
provided with a die surface or face forming the throat or mouth of the die, a
die holder or die block therefor, and means for holding the said dies together
in the said holder, the said die members being of sector-like form and the said
die surface cutting off the angle of such sector, substantially as set forth.
2. In combination in a draw plate or die, the die block or die holder H and the
die consisting of the six sector-like parts D, fitted together and each constituting
an equilateral triangle having one or more of its corners cut away to form the
face or throat of the die, substantially as set forth.
3. In combination in a draw plate or die, the die plate or die holder H and the
die consisting of the sector-like parts D, fitted together and each being reversible
and having two more die faces forming the throat of the said die, whereby two
or more dies may be thereby formed, substantially as set forth.
4. A reversible die member or part, provided with two or more die faces (as a

page_text: and b) and with sides (as f) the said sides being at such angle to each other that
each of said die faces forms with the adjacent sides a wedge-shaped or sector-like
member, substantially as set forth.
5. As an improvement in draw plates or dies, the die having removable wedge-
shaped or sector-like members or parts provided with a die surface or face (as a)
formed across and cutting off the angle of such wedge or sector, whereby the
said member or part may be removed and replaced with perfect rigidity and
accurate registering, substantially as set forth.
Dated this 15th day of September 1896.
J. G. LORRAIN, M.I.E.E., M.I Mech. E.,
Norfolk House, Norfolk Street, Strand, London, W.C.,
Chartered Patent Agent.