Improvements relating to the Manufacture of Rolled Forgings and to Apparatus therefor.
Year: 1889

page_text: Date of Application, 27th June, 1889
Complete Specification Left, 27th Mar., 1890-Accepted, 3rd May, 1890
PROVISIONAL. SPECIFICATION.
[Communicated from abroad by GEORGE FREDERICK SIMONDS, of Fitchburg,
Massachusetts, United States of America, Engineer.]
Improvements relating to the Manufacture of Rolled Forgings and
to Apparatus therefor.
I, RICHARD COPLEY CHRISTIE, Chairman of The Simonds Steel and Iron Forging
Company, Limited, of City Bank Buildings, Queen Victoria Street, in the City and
County of London, do hereby declare the nature of this invention to be as
follows:-
:-
This invention relates to the manufacture of rolled forgings and to apparatus
therefor.
The said invention comprises an improved method of making screw-threads by
rolling or forging. It also comprises improvements in dies of the kind or class
described in the specification of former Letters Patent dated 9th June A.D. 1885,
No. 7028, and other improvements hereinafter mentioned.
Screw-threads have been heretofore made by rolling a blank between dies, one
or both of which moves and rolis or rotates the blank; in one method of operation
heretofore practised, the metal that is displaced to form the thread, is raised radially
from the blank, so that the diameter of the finished screw at the outside of the
thread is greater than the diameter of the blank from which it is made, and the
diameter at the bottom of the thread is smaller than the diameter of the blank,"
and the blank is not extended or elongated. It has also been proposed to roll a
screw-thread by dies that begin to operate at one end of the blank and indent or
depress the metal to form the thread-groove therein continuously to the other end,
extending the metal lengthwise of the blank instead of radially, and thus elongating
the blank as the thread is formed. In this proposed method, the entire work of
depressing the metal to form the thread-groove is performed by a single ridge on the
die, and the depression of the metal as the blank rotates takes place at one side only
of the blanks thus causing greater resistance to its rotary movement on one die than
on the other so that there will be a tendency to slip on one or the other die and thus
distort the thread.
о
My improved method of rolling or forging a screw-thread is similar to the one
just above described in that the metal is depressed to form the thread-groove and is
displaced lengthwise of the blank, which is elongated as the thread is made, but my
method differs from the former method inasmuch as I employ a series of ridges in
the dies so arranged that each of them will engage in succession with the metal and
form a part of the screw-thread.
In my method, the blank is indented at opposite sides simultaneously by ridges on
the dies so that, at each half rotation of the blanks, a ridge on each die forms a
groove extending half way around the blank, the said grooves formed by the two
dies meeting and constituting a single complete turn or convolution of the
thread-groove. Different ridges on the pair of dies come into operation successively,
each beginning a new turn or convolution of the thread-groove in advance of the
turns or convolutions that have previously been formed by the ridges that have
already met and acted upon the blank.
The apparatus which I have devised for making screw-threads consists of a pair
of oppositely moving dies, each having a number of ridges extending lengthwise of
he die, and slightly inclined to its line of movement; the said ridges being
arranged side by side across the die, the ridge at one side being the longest,
and the successive ridges gradually shorter, or beginning at greater and
greater distances from the forward or leading end of the die, so that,

page_text: in the movement of the die relatively to the blank, one ridge arrives at and begins
to operate on the blank first, and the next. adjacent ridge begins to act later, and
each succeeding ridge begins to act after the preceding ridge has practically
performed its entire work on the blank.
!
The dies for making a screw-thread by forging, in accordance with this invention,
may be parts of composite dies intended to be used in pairs that move in
opposite directions with relation to the blank or billet placed between thein, and
rotated by them as they act upon the said blank to bring it to the required shape.
The forward portion of the composite dies, or parts that first act upon the blank,
are substantially the same in character as the dies shown in the said former
Specification No. 7028. The said dies consist essentially of spreading and reducing
surfaces that incline upward from the base of the die, and diverge from one another
from the leading end or portion of the die that first begins to act upon the blank.
The said spreading and reducing surfaces rise from the base of the die, up to the
shaping or forming surface which is in this instance a plane surface, so that the
portion of the composite die acts to reduce a portion of the blank or billet, which is
originally of a diameter somewhat larger than the head portion, down to the
diameter of the threaded portion of the finished forging measured outside of the
threads.
The shaping surface of the die has a groove or depression; in which the head
portion of the said blank is formed.
The original blank or billet is reduced in diameter by the forward portion of the
composite dies, and may then be considered as the blank upon which the threading
portion of the die, to which the present invention especially relates, is to operate.
The base or main portion of the said die has also surfaces which simply serve to
guide and assist in the rotation of the said blank, without tending to forge it or.
change its shape.
The effective portion of the die consists of the leading ends of a series of ridges or
projections, extending lengthwise of the die, but inclined to its path of movement
and the entire series of ridges occupy the entire width of the portion of the die that
is to form the screw-thread.
The ridge at one side of the die extends furthest forward towards the leading end
of the die, and the next ridge begins at a greater distance from the leading end, and
the next ridge at a still greater distance and so on, the leading ends of the ridges
thus lying in a diagonal line across the surface of the die.
When it is necessary to provide for the easy entrance of the ridges into the metal,
the leading ends of the different ridges are inclined upward from the surface of the
base of the die, and are also inclined to the path of movement of the die, and, when
necessary for the purpose of engaging the metal positively and ensuring its rotation,
they are suitably corrugated or roughened.
+
: 1.
By this construction and arrangement, their effect is like that of the main
spreading, and reducing surfaces of the die the said leading ends gradually entering
into the metal and spreading or forcing the surplus or displaced metal lengthwise of
the blank, in this instance all in one direction.
. The screw-thread is thus produced by forming a spiral groove in the blank by
depression of the metal, and extending the blank lengthwise as the metal is
displaced, instead of upsetting or forcing the metal up to a greater diameter than
that of the blank, and thus raising the screw-threads upon the blank.
The work of displacing the metal to form the screw-thread is performed by the
leading ends of the ridges, and the remaining parts of the ridges run in or engage
with the portion of the screw-thread that has already been formed by the leading
ends of the ridges, and the different turns of the thread-groove are begun successively,
one complete turn being. made by one or another pair of ridges during each half
rotation of the blank. The metal is operated upon at opposite sides of the blank.
simultaneously but only for a small number of turns at once, namely when the leading
ends of the one or more ridges of the upper and under die, that meet the blank during
a half rotation thereof, operate,

page_text: For very small threads it is not necessary that the leading ends of the thread-
forming ridges, should be bevelled or inclined, although this form is the best for
properly controlling the flow or change of shape of the metal, especially when the
thread is of considerable size.
The dies are sometimes adapted to produce a screw-threaded bolt with an enlarged
knurled head and if desired with a small journal or pivot portion.
The head portion of the forging has its surface knurled by portions of the dies as
hereinafter mentioned.
The dies are also provided with portions by which the ends of the finished forging
are cut off.
The different parts of the composite die may be made in separate pieces, 'adapted to
be fastened together in a bed-plate. Or the entire die may be made of a single piece.
Or the portion of the composite die, forming the subject of the present invention,
may be used alone to operate on a suitably shaped blank, or billet. It is, however,
in many cases preferable to assemble all the dies required to make a given forging
into a single composite die, so that the forging may be completed at a single operation,
and at a single heat.
To provide for knurling or corrugating the bolt-head or other part of the blank, I
provide one of the dies with a series of projections or ridges, which indent or
produce a corresponding series of depressions or grooves in the surface of the blank
or billet, and the other die is provided with a series of ridges or projections, which
also produce a series of depressions or grooves on the same part of the surface of
the blank, but the ridges of the two dies are so arranged, that the corresponding
grooves produced by them on the forging intersect one another, and thus form a
number of separate projections on the surface of the forging.
.
The direction, size and shape of the ridges on the dies, may be made according to
the character of the surface to be produced, and the construction and arrangement of
the knurling dies may be varied in numerous ways.
Between the spreading and reducing portions of the dies are the raised forming
surfaces which, in connection with the spreading and reducing surfaces, give the
forging the desired shape in longitudinal section.
The ridges for producing the knurled surface may be of any desired shape, and set
at any desired angle to the path of movement of the dies, and one set of ridges may
be finer, or of different shape from the other set, thus varying the character of the
surface produced, according to the purpose for which the article is intended.
For example one set of ridges may be parallel with the path of movement of the
dies, and produce a set of circumferential grooves, around the forging, and the other
set be at right angles to the path of movement of the dies, and produce a series of
longitudinal grooves in the forging.
The article to be knurled is acted upon at diametrically opposite sides, and
indented or grooved while being rotated so that the indentations or grooves produced
simultaneously at opposite sides, are' carried progressively around the surface as the
blank rotates, and one set of grooves is made, at a different angle in the surface
from the other set, so that the' said grooves intersect one another as above
mentioned.
In some instances the rigid or knurling portions intersect and co-operate with
the spreading and reducing surfaces, so that the surface of the forging is knurled
progressively at the same time that this portion of the forging is brought to the
desired shape. The knurling surfaces are sometimes arranged on a high part of the
forming surface of the die; and consequently the surface of the forging is depressed
with relation to the part of the forging produced by the forming surface of the dies,
at the same time that it is knurled, and the grooves or ridges of the knurled portion,
instead of being impressed into the entire length of the knurled portion at once,
are impressed first in a short portion of the said surface, and then gradually
lengthened as the said surface is brought, by the spreading surfaces of the die, to the
desired diameter.
:
;
The surfaces of the dies that meet the forging after the knurling surfaces have

page_text: acted upon it, are of such height as not to press upon the projections or knurling of
the forging, but merely engage with the same sufficiently to assist in guiding the
forging as it is subsequently acted upon by the other parts of the die.
-Knurling dies, or ridged portions, may be employed as parts of composite dies,
having other parts that perform various other operations in the production of rolled
forgings.
I sometimes make a dental instrument or the like having the handle knurled by
grooves that intersect at right angles to one another, one set of the said grooves
being parallel with the axis of the forging, and the other set at right angles to the
axis, or the said grooves being otherwise suitably arranged.
The forging is rolled to any desired shape by the oppositely moving dies, and the
knurling produced by the ridged portions of the said dies, the entire forging being
rolled to shape, and any desired portion of its surface being knurled or provided with
intersecting grooves and intermediate projections at a single operation.
Dated this 27th day of June 1889.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant."
COMPLETE SPECIFICATION.
Improvements relating to the Manufacture of Rolled Forgings and
to Apparatus therefor.
I, RICHARD COPLEY CHRISTIE, Chairman of the Simonds Steel and Iron Forging
Company, Limited, of City Bank Buildings, Queen Victoria Street, in the City and
County of London, 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:-
This invention relates to the manufacture of rolled forgings and to apparatus therefor.
The said invention comprises an improved method of manufacture whereby I am
enabled to produce a screw-threaded forging in one operation by rolling a metal bar
or blank between dies arranged to move in opposite directions, and provided with
surfaces for spreading the surplus metal and reducing and shaping the said bar or
blank, and with ridges or projections for forming the screw-threads thereon.
The said invention further comprises means for knurling the surface of the heads
or other portions of the screw-threaded forgings; and it also comprises improvements
in dies of the kind or class described in the specification of former Letters Patent
dated 9th June A.D. 1885 No. 7028.
The formation of the screw-threads in the manufacture of screws or screw-bolts has,
in some instances, been effected by rolling a blank between dies, by the relative
movement of which the blank is caused to rotate about its axis. According to one
method of manufacture heretofore practised, the metal that is displaced to form the
groove is raised radially from the blank and forms part of the thread, so that the
diameter of the finished screw at the outside of the thread is greater than the diameter
of the blank from which the screw is made, and the diameter at the bottom or inside
of the thread is smaller than the diameter of the said blank; moreover the blank is
not extended or elongated to any appreciable extent. It has also been proposed to
form screw-threads on bars or blanks by rolling between dies which begin to operate
at one end of the blank and indent or depress the metal continuously to the other end
to form the thread-groove therein, the metal being extended lengthwise of the blank
instead of radially, and the blank being thus elongated as the screw-thread is formed.
In this proposed method, the entire work of depressing the metal to form the thread-
groove is performed by a single ridge on the die and the depression of the metal, as
the blank rotates, takes place at one side only of the blank, thus causing greater
resistance to its rotary movement on the one die than on the other die, so that
the blank will have a tendency to slip on one or the other die and thus distort
the thread.
My improved method of manufacturing screw-threaded forgings is similar to that

page_text: ;
last above described, inasmuch as the metal is depressed to form the thread-groove
and is displaced lengthwise of the blank, which is elongated as the thread is formed
but my method differs from the former method inasmuch as I employ a series of
ridges on the dies, so arranged that the said ridges will engage in succession with the
metal bar or blank and each of them will act thereon to form a part of the screw-
thread.
In my method, the blank is indented at opposite sides simultaneously by ridges on
the dies, so that, in cach half rotation of the blank, a ridge on each die forms a groove
extending half way around the blank, one of the said grooves joining the other so as
to constitute a single complete turn or convolution of the thread-groove. Different
ridges on the dies come into operation successively, each beginning a new turn or
convolution of the thread-groove in advance of the turns or convolutions which have
previously been formed by the ridges that have already acted upon the blank.
My improved dies are made with a number of ridges arranged side by side across
the die, and extending along the same in a direction slightly inclined to the direction
of movement of the die; the ridge at one side being the longest, and the successive
ridges gradually shorter, or beginning at greater and greater distances from the
forward or leading end of the die, so that, in the movement of the die relatively to
the blank, the longest ridge first arrives at and begins to operate upon the blank, and
then the next adjacent ridge, and so on, each succeeding ridge commencing its action
when, or just before the preceding ridge has practically performed its entire work on
the blank.
In the accompanying drawing,
Figure 1 is
perspective view of a composite die for the manufacture of screw-
threaded forgings as hereinafter described.
Figure 2 is a perspective view of a portion or section of the co-operating die.
Figures 3, 4 and 5 are diagrams showing the blank at three successive points or
stages in the process of making the screw-thread thereon.
Figure 6 is a side elevation of the finished forging made by a pair of dies such as
that shown in Figure 1, and
Figure 7 is a side elevation of another forging made by dies constructed in
accordance with my present invention.
Composite dies, such as that shown in Figure 1, are intended to be used in pairs
and to move in opposite directions and act upon the blank or billet placed between
them, so as to rotate the said blank and bring it to the required shape.
a, a are the portions or sections of the dies for making the screw-threads on the
forgings in accordance with this invention. b is the portion or section of the die for
reducing the blank at the part to be screw-threaded. c is another portion or section
of the die for knurling the head of the screw, and d is another portion or section of
the die for severing the forging from the bar and cutting it to the desired length..
The forward portion or section b of each composite die, that is to say, the portion or
section thereof that first acts upon the blank, is substantially the same in character as
the dies described in the said former Specification, the said portion or section b
consisting essentially of spreading and reducing surfaces b' which incline upward
from the base of the die, and diverge from one another from the leading end 2 of the
die, and a shaping or forming surface which is, in this instance, a plane surface.
The said section of the composite die, therefore, acts to reduce a portion of 'the
blank or billet, which is originally of a diameter somewhat larger than the head
portion (Figure 3) of the forging, down to the diameter of the part thereof,
which is equal to the outside diameter of the screw-threads of the finished forging k
(Figure 6). The shaping surface 62 of the die-section 6 has, moreover, a groove or
depression in which the head portion i of the forging is formed.
The blank or billet is reduced in diameter by the forward portion 6 of the composite
dies to the shape shown in Figure 3, and when so formed it may be considered as the
blank to be operated upon by the screw-threading portion or section a of the dies, to
which the present invention more especially relates.
The base or main portion of the said die-section a has surfaces a³, a³ corresponding

page_text: to the surfaces 62, 63.at the adjacent end of the dic-section . The said surfaces a², a³
therefore correspond to the shape of the blank i, ¹, Figure 3, and simply serve to
guide and assist in the rotation of the said blank, without tending to forge it or.
change its shape.
The effective or operative part of the die-section a consists of the forward or leading,
ends of a series of ridges or projections a, a, a, a, a, 7º. These ridges or pro-
jections extend. along tho die in a direction slightly inclined to its path of movement,
this inclination corresponding to. the pitch of the screw-thread.
The ridge a' at one side of the die extends furthest forward or nearest to the leading
end of the die, the next, ridge a begins at a greater distance from the leading end
of the die, and the ridge a. at a still greater distance therefrom, and so on, the forward
or leading ends of the said ridges thus lying in an oblique line across the surface a²
of the die.
...When it is necessary to provide for the easy entrance of the ridges into the metal,
the leading ends of the said ridges are bevelled or inclined upward from the surface a
of the die, and are also inclined to the path of movement of the die, as shown, and,
when necessary, to ensure their engagement with the metal positively for the purpose
of effecting its rotation, they are roughened or serrated as shown. By reason of this
construction and arrangement, their effect is like that of the spreading and reducing
surfaces 6 of the die-section b, the said leading ends of the ridges gradually entering.
into the metal and spreading or forcing the surplus or displaced metal lengthwise of
the blank, in this instance, all in one direction, viz. -from the side 3 towards tho
side 4 of the die-section a.
-The screw-thread is thus produced by forming a spiral groove in the blank by
depression of the metal, and, at the same time, extending the blank lengthwise as
the metal is displaced, but the said groove, instead of being formed continuously, is
produced as follows, that is to say:-The work of displacing the metal to form the
screw-thread is performed by the leading ends of the ridges, the remaining parts of
such ridges running in or engaging with the portions of the screw-threads formed
by the said leading ends. The different turns or convolutions of the thread-groove.
are begun successively, a complete turn or convolution being made by one or other
of the ridges on the one die and by the opposite ridge on the other die during a half
rotation of the blank, and. the blank being operated upon simultaneously at opposite
sides thereof by this pair of ridges. The second turn or convolution of the thread-
groove may be commenced by the second pair of ridges a short time before the first
pair of ridges has completed the first turn or convolution and so on.
The improved method of making screw-threads in accordance with this invention
will be more fully understood from the following description with reference to
Figures 3, 4 and 5, which more clearly show the manner in which the dies or die-
sections a operate upon the blank i, . The portion of the blauk to be screw-
threaded is first indented or depressed at or near one end thereof at opposite sides
simultaneously, as represented at 6 and 7. These indentations are then continued or
extended by the movement of the dies and by the rotation of the blank, spirally
around the surface of the blank until the groove begun at 6 reaches the point 7,
thus making a continuous spiral groove from 6 to 7, which is the grooved portion on
the rear side of the blank represented in dotted lines in Figure 4. The groove
begun at 7 is at the same time continued or extended half-way around the blank to
the point 8 as represented by full lines in Figure 4, so that, in a half rotation of
the blank, one complete turn or convolution of the groove and consequently of the
screw-thread is made; this operation being performed by the longest ridges a* of the
dies. Before or at the termination of this half rotation of the blank, the second
ridge a of the one die begins to act at 8, and the second ridge a of the other die
begins to act at 9, Figure 4, and, in the next half rotation of the blank, the said
groove is continued half way around the blank by one die from 8 to 9 as shown by
full lines in Figure 5 while the other die is making the groove from 9 to 10 as shown
by dotted lines in Figure 5. After these ridges a have performed their work, the

page_text: next ridges a of the dies begin to act at 10 and 11 respectively and the operation
continues in this manner until a screw-thread of the desired length is completed.
The portion of the thread-groove which is made in one half revolution of the
blank, is not substantially affected by the dies in the continued movement thereof,
but merely runs along the ridges of the dies whereby it has been formed, and which
serve to guide the blank and present the new parts thereof in the proper position, to
the action of the other ridges of the dies.
The screw thread is thus formed in the blank by 'impression 'or indentation, pro-
gressively from one end to the other, each ridge of each die beginning to act at a new
point on the blank in advance of the part already acted upon and grooved by the
preceding ridge of the other die.
For very small screw-threads it is not necessary that the leading ends "of "the
thread-forming ridges should be bevelled or inclined, as shown, although this form is
preferable (especially when the thread is of considerable size) as it ensures the proper
control of the flow or change of shape of the metal.
"
The composite die shown in Figure 1 is adapted to produce a screw-threaded'
bolt (Figure 6) with an enlarged head k¹, and with a small journal or pivot"
portion this threaded bolt is intended for operating the movable jaw of a monkey-
wrench or shifting spanner.
The head of the forging has its surface knurled by portions or sections c of the
composite dies, the construction and operation of which is hereinafter described.
The die-section c constructed according to this invention for knurling the head
of the screw k, is shown in Figure 1 as part of a die which, also embodies the
screw-threading section a above described, and the die-section by constructed, as
described in the said former specification:
1.
1
The said die-sections c are provided with ridges or projections c' which are so'
arranged that the grooves formed in the blank by the projections c¹ on one die or die-
section will intersect those formed by corresponding projections on the other die or
die-section.
.
1. J.
+7
The portions or sections d of the die have cutting edges and spreading surfaces at d¹
by which the ends of the finished forging are cut off, these portions being substantially'
the same as those described in the said former specification.
1...
The different parts of the composite die shown in Figure 1 are intended to be
fastened together or firmly secured in their proper relative position in a suitable platen'
which may be arranged in any convenient manner in the machine. It is obvious,
however, that if desired the entire die may be made of a single piece of metal and
also that the portion or section a of the composite die, or a 'die constructed in' a
similar. manner to the said portion or section may be used alone to operate on a
suitably shaped blank or billet to form screw-threads thereon, In many cases it is
preferable to assemble all the dies or die-sections required to make a given forging
into a single composite die as above described, so that the screw-threaded forging may
be completed in a single operation, and with a single heat.
I sometimes so construct my improved composite dies that I can produce thereby,
in one operation and at a single heat a screw-bolt such as that shown in Figure 7,
having one or more projections / or a square oval or other non-circular part under the
head for preventing the turning of the bolt while the nut is being screwed thereon.
For this purpose I combine, with the other portions or sections of the dies, sections
constructed as described in the specification of my application for Letters Patent
No. 10,454 bearing the same date as the present application.
It is evident that, by varying the construction of my improved dies as required,
I can produce various kinds of screw-threaded forgings in the manner above
described.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to me
by my foreign Correspondent, I wish it understood that I claim :-
First. The improved method of making screw-threads on metal bars or blanks,
:

page_text: which consists in indenting the blank at opposite sides to the full depth of the thread-
groove, and then, whilst rotating the said blank about its axis, extending the inden-
tations spirally around the same so as to produce a complete turn or convolution of
the thread-groove, and forming similar indentations successively in the blank and
extending such indentations, substantially as hereinbefore described.
Second. The herein described method of forging screw-threads, by rolling a metal
bar or blank between dies moving in opposite directions and provided with indenting
ridges so arranged that they will be forced in succession into the blank to form the
thread-groove and each ridge on each die will form one half of a turn or convolution
of the said groove.
Third. The manufacture of a screw-threaded forging in one operation, by rolling a
metal bar or blank between dies moving in opposite directions and having spreading
and reducing surfaces for shaping the said bar or blank, and ridges or projections for
forming the screw-threads thereon, substantially as herein before described.
Fourth. A die for the purpose above specified, having indenting ridges which are
parallel to each other and inclined to the direction of movement of the die, and which
are so arranged that they will operate, or commence to operate in succession upon the
blank and will form successive portions of the thread-groove.
Fifth. A die for the purpose above specified, having indenting ridges which are
parallel to each other and inclined to the direction of movement of the die, and the
forward or leading ends of which are inclined to the base or bed-portion of the die,
and may or may not be provided with teeth or serrations, all substantially aš, and
for the purposes, set forth.
Sixth. A composite die for the purpose above specified, one of the portions or
sections of which is provided with indenting ridges for forging screw-threads in the
manner herein before described.
Seventh. A composite die for the purpose above specified, one of the portions or
sections of which is adapted for forging screw-threads and another portion or section
of which is adapted for knurling a part of the screw-threaded forging.
Eighth. A screw-bolt or other screw-threaded forging having an enlarged portion
or head and formed in one operation by rolling, substantially as hereinbefore
described.
Ninth. A screw-bolt or other screw-threaded forging, the head or other portion of
which is knurled, and which is formed in one operation by rolling, substantially as
herein before described.
Tenth. A screw or screw-bolt in which the screw-thread, the shank, the head and
the square, oval or other non-circular part under the head are all formed in one
operation by rolling.
Dated this 27th day of March 1890.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.