Year: 1888

page_text: Date of Application (in United Kingdom), 7th Sept., 1888
Complete Specification Left, 7th Sept., 1888
Complete Specification Accepted, 23rd Mar., 1889
I DANIEL EDGAR KEMPSTER of Boston in the State of Massachusetts one of the
United States of America, Inventor 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 :-
My invention relates to dies for roll-forging metal blanks into articles of various
longitudinal configuration, but having circular cross-sectional area; and my object is
to provide dies which will impart superior qualities to the metal being worked, and
also hasten the operation of forging.
My invention consists in constructing and arranging the forming, reducing, and
spreading surfaces of the dies entirely within working-grooves running obliquely to
the line of rotation of the metal article being rolled therein, or to the line of move-
ment of said dies proper, whereby metal blanks when separated from the rod or bar
and introduced between said dies will be bodily confined within said working grooves,
and there be obliquely acted upon while being rolled into the desired shape of the
finished article.
In the drawings forming a part of this specification, Figure 1 is a plan view of two
straight dies embodying my invention; Fig. 2, an end view of the same; Fig. 3, a
side elevation of a conical bullet as rolled in said dies. Fig. 4 is a plan view of two
curved dies; Fig. 5, an end view of the same: Fig. 6, a side elevation of a screw
blank as rolled in said dies. Fig. 7 is a plan or face view of two segmental dies;
Fig. 8, a sectional view of the same on the line A B in Fig. 7; Fig. 9, an end view
of Fig. 7; Fig. 10, a side elevation of a boiler-rivet as rolled in said dies. Fig. 11
is an end elevation of two conical or tapering roll dies; Fig. 12, a section of the same
L Prine R

page_text: on the line CD in Fig. 11: Fig. 13, a side elevation of a common round-head rivet¨
as rolled in said dies. Fig. 14 is a side elevation of two roll-dies as in operation
obliquely to each other; Fig. 15, an end elevation of the same; Fig. 16, a side
elevation of a dumb-hell as rolled in said dies; Fig. 17; a side elevation or face view
of one disc-dic; Fig. 18, a cross section of two of said disc dies in working positions;
Fig. 19, a side elevation of a hob-nail as rolled in said dies.
All of the above dies pertain to that class which are used in pairs in suitable
machines designed to hold them with their working faces or grooves adjacent to each
other, and between which the article to be rolled is rapidly revolved by their move-
ment in opposite directions.
I have shown here some of the forms of dics to which I have applied my invention,
and those skilled in the art to which it pertains will readily suggest other forms of
dies to which it may be applied without departing from the essential spirit of my
invention.
1 need not herein describe the various machines for properly handling and operating
the different kinds of dies shown and described by me, as it will be apparent to any
intelligent mechanic on seeing the form and shape of said dies how to hold and move
them properly to obtain the best result.
I need not herein minutely describe the precise shape of the working-groove in the
faces of the different dies shown, as it is sufficient to state that the metal blank is
severed from the rod or bar and enters bodily between the dies at the largest part of
their groove, said dies at that time being in such position relative to each other as to
cause said largest part of said grooves to register. The grooves are usually made
tapering, and are milled or scored for about three-quarters of their length, com-
mencing from their largest end. This insures the rough blanks revolving on entering
said grooves and until formed and condensed nearly down to size, when it will
continue to revolve and be smoothly finished to size by the remaining unmilled or
unscored portions of said dies.
I do not desire to confine myself to any special or particular shape of working-
groove in cross-section, as said grooves may be formed in the dies so as to diverge,
reduce, and spread the metal stock of the blank wherever desired, which will be ever
varied to correspond to the requirements of the shape of the article to be formed by
rolling, it being understood that the metal blank severed from the rod or bar should
contain just sufficient metal to fill the dies full in their smallest space when said metal
is a fully condensed and finished article.
Referring to the drawings similar letters of reference indicate corresponding parts
wherever they occur.
In Figs. 1 and 2, a a are two straight dies arranged face to face and adapted to be
moved in a straight line in opposite directions in the usual manner. a¹ a¹ are the
working-grooves in said dies, formed to produce the bullet, Fig. 3, when a proper-
sized piece of metal is rolled therein. The grooves a¹ a are formed in the dies
obliquely to their line of movement. (Shown in Fig. 1 as a straight diagonal groove,
although curved grooves may be substituted therefor if bearing the same or a similar
relation to the line or plane of the line of motion of the dies proper, a a, as
shown.)
In Figs. 4 and. 5, 6 bare two curved dies arranged face to face and adapted to be
moved in opposite directions in a line coincident with their curve.
are the
working-grooves formed obliquely in the side faces of said dies proper, or on a spiral
or eccentric curve from the centre of motion of the said dies, as shown in Fig. 4,
although straight diagonal grooves may be substituted therefor and bear similar
relation to the line of motion of said dies bb. The grooves b¹¹ are cut to produce
the screw-blank, Fig. 6, from metal rolled therein.
In Figs. 7, 8 and 9, c c are two segmental dies, arranged face to face and adapted
to be moved in opposite directions in an arc of a circle coincident with the radius of
said dies. c c are the working-grooves, formed obliquely or helically in the
periphery of said dies proper, as shown in Fig. 7. Said grooves el c¹ are shaped-to
produce the boiler-rivet, Fig. 10, from a piece of metal rolled therein.

page_text: In Figs. 11 and 12, d d are two conical-shaped or tapering roll-dies, arranged face
to face and adapted to be revolved together in the same direction, thereby causing
their working-faces to move in opposite directions past or by each other. d' are the
working-grooves formed obliquely or spirally in the faces of said die-rolls, as in the
form of a screw-
w-thread, (shown in Fig. 12,) and are shaped to produce the common
round-head rivet, Fig. 13, from metal blanks rolled therein. The largest part of the
grooves d' is formed in that part of the rolls having the greatest diameter, as this
gives more bearing-surface on the metal blank when entering and first being rolled in
said grooves, and thus prevents said blank from slipping or rolling out of its proper
central position. As the metal article is being rolled into shape, it is moved bodily
lengthwise of said die-rolls, or parallel with a centre line between their axes of
rotations, being caused to bodily travel thus at an angle to the line or plane of the
movement of the dies proper by the action of the opposing spiral grooves d' d', which
confine and both revolve and convey or carry the metal blank along from one end of
said die-rolls to the other, where it is thrown out completed and finished to size. It
is obvious that the said dic-rolls may be made in the form of a sleeve or tube
instead of solid, and for some certain kinds of work they would be preferably so
made.
In Figs. 14 and 15, e e are two die-rolls, arranged face to face, but obliquely to
each other. They are adapted to revolve together in the same direction, thereby
causing their adjacent and opposing faces to move by or past each other in opposite
directions. ee are the eccentric working-grooves, formed in line with their
individual line or plane of movement, thereby differing in construction specifically
with the other dies herein shown and described; but by arranging said die-rolls with
their axes oblique to each other, as shown in Fig. 14, I am able to obtain that
obliquely drawing influence upon opposite sides of the article being rolled which is
given to it by dies having their grooves formed obliquely to their line of motion, as
before described, and for some kinds of work the dies e e would be preferable. The
grooves el el are shaped to form the dumb-bell, Fig. 16, from metal blanks rolled
therein.
In Figs. 17 and 18, ff are disc-shaped dies adapted to be arranged side by side and
revolved together in opposite directions. f1 f1 are the working-grooves on the side
faces of said dies, formed therein obliquely or eccentrically to the circle of their
movement, similar to a scroll, and, designed to face each other when in working
position, as shown in Fig. 18. Said dies are represented as cut to produce the hob
nail, Fig. 19, from pieces of metal rolled therein. It is obvious that the said disc-dies
may be made with bevelled faces instead of flat, as shown, and for certain kinds of
work may be preferable, and in either case the metal blank enters the die-groove at
its largest part, which is preferably at the periphery, and is gradually rolled into
shape as it is bodily carried within said groove toward the centre of the disc, where it
is thrown out completely rolled and finished.
The advantages derive from constructing the working-grooves in the dies and
arranging thein to act in accordance with my invention-riz., so as to bodily confine
and obliquely act upon the article being rolled-are, first, in rolling articles such as
bullets, screw-blanks, various kinds of rivets, nails, &c., I am able to produce a
superior class of work, as the oblique action of the dies upon the confined metal blank
tends to force said metal endwise into that part of said die-grooves which forms the
heads or points desired to be brought out full and sharp on the article being rolled;
second, the oblique action of the dies upon the confined metal blank tends to condense
and slightly twist the fibres of said metal blank, thereby closing up any seams or
imperfections which may have existed in the rod or bar from which said blank was
severed, and this produces a superior article, especially in a screw or nail, as the twist
given the fibres effectually prevents their splitting when being driven; third, and,
perhaps, the greatest advantage referred to is the fact that with my invention applied
to revolving dies similar to those shown in Figs. 11, 12, 17, and 18 I am able to
greatly increase the production of small metal articles over and above any machine or
method now employed in the manufacture of similar work.

page_text: The above fact is accomplished by the oblique die-grooves confining and carrying
the articles being rolled bodily along out of the way of each other, thereby permitting
the dies to he continuously revolved at a very high rate of speed, as I do not have to
depend upon gravity to carry the finished articles out of the dies and away from each
other, as heretofore. My improved die-grooves, when revolved rapidly, as described,
are capable of receiving a continuous stream of metal blanks in one end of said
grooves, and will roll to size and pass them out the opposite end without clogging.
It will therefore be obvious that while I have shown several forms of reciprocating
dies constructed in accordance with my invention I prefer in the manufacture of small
articles to use dies continuously rotary, and special forms of them, and also machines
for operating them.
The reciprocating dies herein shown are better adapted for a heavier class of work
than is shown on the drawings. The die-groove shown in Fig. 4 is a preferred form
of construction, and may be used upon the rotary dies, Figs. 12 and 18. Said groove
is tapering two ways, so as to take in a large but short piece of metal, and then
reduce its diameter, but extend its length, as will be fully understood by referring to
the drawings. All the metal blanks shown within the dies are marked e, and all the
milled or scored surfaces of said dies are marked z.
In rotary dies as heretofore constructed, having their working-grooves in line with
the line or plane of their rotation, the articles being rolled leave said dies by gravity
alone, and a new blank cannot enter said dies until the one last rolled drops out. This
is obviously slow as compared with my improvements, as herein described and
shown.
Rolling metal circular between die-faces moving in opposite directions and rolling
screw-threads into cylindrical surfaces by spiral projections on said die-faces are both
old and well known in the art; but I believe myself to be the first to make and use
the invention herein desired and claimed.
Having now particularly described and ascertained the nature of my said
Invention and in what manner the same is to be performed, I declare that what I
claim is :
Dies for roll-forging metal articles having circular cross-sectional area from metal
blanks separated from the main rod or bar, said dies having their forming, reducing,
and spreading surfaces entirely within working-grooves running obliquely to the line
of rotation of the metal article being rolled therein, or to the line of movement of the
dies proper, substantially as herein specified, and for the purpose set forth.
Dated the 7th day of September 1888.
WM. BROOKES & SON,
55 & 56, Chancery Lane, London,
Agents for the Applicant.