IMPROVEMENTS IN SHAPING AND FORGING METALS, AND IN THE MACHINERY OR APPARATUS EMPLOYED THEREIN
Year: 1866

page_text: LETTERS PATENT to Robert Mitchell, of Wolverhampton, in the County
of Stafford, Engineer, for the Invention of "IMPROVEMENTS IN SHAPING
AND FORGING METALS, AND IN THE MACHINERY OR APPARATUS EMPLOYED
THEREIN."
Sealed the 8th February 1867, in pursuance of an Order of the Lord Chancellor,
TI
PROVISIONAL SPECIFICATION left by the said Robert Mitchell at the
Office of the Commissioners of Patents, with his Petition, on the 21st
July 1866.
I, ROBERT MITCHELL, of Wolverhampton, in the County of Stafford,
Engineer, do hereby declare the nature of the said Invention for "IMPROVE-
MENTS IN SHAPING AND FORGING METALS, AND IN THE MACHINERY OR APPARATUS
EMPLOYED THERELE," to be as follows:-
This Invention relates partly to certain improvements upon the Invention
for which Letters Patent were granted to James Alfred Shipton and myself,
on the 19th of January 1865, No. 165, and has for its object the facilitating
the operation of finishing the partly forged "tees," "elbows," "bends,"
"crosses,"
couplings," and other pipe fittings mentioned in the Specification
of the said Patent.
According to this part of my Invention I propose to employ in addition to
the apparatus described in the Specification of the Patent herein-before
referred to for finishing the forgings a pair of claws, swages, or moulding

page_text: jaws, which are caused to hip the forging tightly between them, and thereby
impart the desired shape or finish thereto. In combination with these moulding
jaws I employ a pair of converging dies, which in lieu of embracing half the.
circumference of the article operated upon, as described in the Specification
herein-before referred to, embrace only about one quarter of its surface, the
other two quarters being embraced by the moulding jaws between which the
dies operate; these moulding jaws may be opened and closed by any con-
venient arrangement, as, for example, by means of a wedge action worked
from the vertical cylinder of the machine, or by means of a system of toggle-
joint levers, also brought into operation by the vertical cylinder and actuating
a horizontal slide which closes one of the jaws, whilst the other is closed by a
vertical incline or wedge.
Another part of my Invention consists of a peculiar arrangement of the
parts of the cylinder of the forging machines with a view to "cushioning" or
confining the steam above the piston, and thereby preventing the piston
striking against the cylinder cover when steam is admitted below it.
In carrying out this part of my Invention I make the steam port some
distance below or from the top or end cover of the cylinder so as to leave a
steam space above the piston after it has "cut off" the steam by covering the
port; round the interior of the cylinder are formed a separate series of steam
ways or passages for establishing a communication between the upper and
under sides of the piston, the distance between the upper and lower ends of
such passages being rather more than the thickness of the piston, and the
upper ends of these passages are a little above the upper edge of the steam
port. It will thus be seen that as the piston is driven up by the steam
pressure below it cuts off the steam escaping through the upper port, and
confines a portion in the space above that port, such confined steam acting as
a cushion. On the recoil of the piston a communication will be established
between the upper and lower sides of the piston by the steam ways before
referred to, and a perfect equilibrium will be obtained so long as the piston is
not in operation, but on the admission of fresh steam above the piston it
will be forced down to its work, and when the escape is opened will rise
again and its course will be arrested as before described just before reaching
the cover of the cylinder. This arrangement is obviously applicable to all
double-action steam hammers for general forging purposes.

page_text: SPECIFICATION filed in pursuance of the conditions of the Letters Patent,
and of an Order of the Lord Chancellor, by the said Robert Mitchell in
the Great Seal Patent Office on the 13th February 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
MITCHELL, of Wolverhampton, in the County of Stafford, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-first day of July, in the year of our Lord One
thousand eight hundred and sixty-six, in the thirtieth year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Robert Mitchell, Her special license that I, the said Robert Mitchell,
my executors, administrators, and assigns, or such others as I, the said
Robert Mitchell, my executors, administrators, or assigns, should at any
time agree with, and no others, from time to time, and at all times there-
after during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain and
Ireland, the Channel Islands, and Isle of Man, an Invention for "IMPROVE-
MENTS IN SHAPING AND FORGING METALS AND IN THE MACHINERY OR APPARATUS
EMPLOYED THEREIN," upon the condition (amongst others) that I, the said Robert
Mitchell, my executors or administrators, by an instrument in writing under
my hand and seal, should particularly describe and ascertain the nature of
the said Invention, and in what manner the same was to be performed, and
cause the same to be filed in the Great Seal Patent Office on or before the
Thirteenth day of February, One thousand eight hundred and sixty-seven.
NOW KNOW YE, that I, the said Robert Mitchell, do hereby declare.
the nature of my said Invention, and in what manner the same is to be per-.
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the accompanying Drawings, and to the
letters and figures marked thereon, that is to say :-
My said Invention relates partly to certain improvements upon the Invention
for which Letters Patent were granted to James Alfred Shipton and myself,
en the Nineteenth of January 1865, No. 165, aad has for its object the
facilitating the operation of finishing the partly forged "tees," "elbows,"
"beads," " crosses,"
," "couplings," and other pipe fittings, mentioned in the
Specification of the said Patent.
. According to this part of my Invention I propose to employ in addition to
the apparatus described in the Specification of the Patent herein-before
referred to for finishing or welding the forging a pair of clams, swages, or

page_text: moulding jaws which are caused to nip the forging tightly between them, and
thereby impart the desired shape or finish thereto. In combination with these
moulding jaws I employ a pair of converging dies, which in lieu of embracing
half the circumference of the article operated upon, as described in the
Specification herein-before referred to, embrace each only about one quarter
of its circumference, the other two quarters being embraced by the two
moulding jaws or clams between which the dies operate; these moulding jaws
may be opened and closed by any convenient arrangement, as, for example, by
means of a wedge action worked from the vertical cylinder of the machine, or
by means of a single link, or a system of toggle-joint levers, also brought into
operation by the vertical cylinder and actuating a horizontal sliding frame
which closes one of the jaws, whilst the other is closed by a vertical incline
or wedge.
Another part of my Invention consists of a peculiar arrangement of the
parts of the cylinders of the forging or welding and bending or shaping
machines with a view to "cushioning" or confining the steam, compressed
air, or other elastic fluid employed above the piston, and thereby preventing
the piston striking against the cylinder cover when steam is admitted
below it.
In carrying out this part of my Invention I make the steam port some
distance below from the top end cover of the cylinder, so as to leave a
steam space above the piston after it has "cut off" the steam by covering the
port. Round the interior of the cylinder are formed a separate series of
steam ways or passages for establishing a communication between the upper
and under sides of the piston, the distance between the upper and lower ends
of such passages being rather more than the thickness of the piston, and the
upper ends of these passages are a little above the upper edge of the steam
port. It will thus thus be seen that as the piston is driven up by the steam
pressure below it cuts off the steam escaping through the upper port and
confines a portion in the space above that port, such confined steam acting as
a cushion. On the recoil of the piston a communication will be established
between the upper and lower sides of the piston by the steam ways before
referred to, and a perfect equilibrium will be obtained so long as the piston
is not in operation, but on the admission of fresh steam above the piston it
will be forced down to its work, and when the escape is opened will rise again
and its course will be arrested as before described, just before reaching the
cover of the cylinder. This arrangement is obviously applicable to all double-
action steam hammers for general forging purposes.
And in order that my said Invention may be fully understood I shall now

page_text: proceed more particularly to describe the same, and for that purpose I shall
refer to the several Figures on the annexed Sheet of Drawings, the same
letters of reference indicating corresponding parts in all the Figures.
""
" "
Figure 1 of my Drawings represents a front elevation of my improved
welding or forging machine as adapted for the manufacture of "tees,"
"elbows," "bends," crosses,' 'couplings," and other like pipe fittings;
Figure 2 is a corresponding side elevation of the same; Figure 3 is an
elevational detail, showing the mode of actuating the clams or jaws; Figure 4
is a sectional detail showing the conjoint action of the mandrills, dies, and
mould block, the jaws or claws not being visible in this Figure; and Figure 5
is a sectional detail of one of the cylinders.
A is the table of the machine, which may be supported on convenient
standards, not shown in my Drawings; this table carries a strong upright
standard B, to which are bolted the brackets C and D, D, carrying the
respective cylinders E and F, F. The cylinder E is placed vertically and in
a reversed position, that is to say, with its piston rod G working through a
stuffing box in the lower end cover thereof; whilst the other two cylinders F, F,
are situate at an angle of about 45° on each side of the vertical cylinder, and
like it operate in a reversed position, the rods H, H, working through stuffing
boxes in the lower end covers, of the cylinders. Each of the three cylinders
is provided with an ordinary slide or other suitable, valve working in the
respective valve boxes I, K, K, aud deriving their motion from the band of
the attendant, through the intervention of the hand levers L and M res-
pectively, the lever L actuating the valve of the vertical cylinder E through the
rod N. and lever O, whilst the lever M transmits motion to the valves of the
cylinders F, F, through the rods P, Q, and levers R, S, and T. The rod Q is
made adjustable in length, so as to enable the positions of the two slide valves
to be accurately adjusted, and thereby ensure the simultaneous action of the
respective pistons in the cylinders F, F. By suitably moving the two hand levers
L and M the attendant has perfect command over the three cylinders causing
the vertical cylinder or the two oblique ones to operate at pleasure. The
piston rod G of the vertical cylinder is.keyed to a slide U working in guides
in the vertical standard B. This slide carries a projecting bracket V, to which
is secured the vertical mandrill (Figure 4). Two other mandrills k, k,
working horizontally are secured to the two horizontal slides W, W; these
slides are caused to approach towards and recede from the mould block r
simultaneously by the action of the lever arms y, y, working in slots or
recesses in the slides and keyed on to the rocking spindles Z, Z, supported by
the brackets a, a, bolted to the under side of the table A, and by the base

page_text: plates b, b, secured to convenient standards or supports; Y', Y, are other
lever arms also keyed on to the rocking spindles Z, which arms are alternately
elevated and depressed by the action of the studs or pins d, d, in the lower
portion of the vertical slide U, as shown clearly in Figure 1; e, e¹, (Figure 3,)
are a pair of clams, swages, or moulding jaws which are shaped on their
gripping faces so as to accurately fit a portion of the surface of the article to
be welded.
In my Drawing (Figure 3) I have represented these jaws as each
embracing about one-third the circumference of the article, the remaining
portion between the two jaws on the under side of the article being supported in
the hollow of the mould block r, whilst that portion on the upper surface
where the weld is to be made is left exposed so as to be free to be acted upon
by the welding dies or tools c, c, fitted to the lower ends of the converging
piston rods H, H, of the cylinders F, F. The clams or jaws e, e¹, are hinged at
ff, to lugs in the surface of the table disposed one on each side of the mould
block r; g is a plate bolted to the ends of four horizontal sliding rods h, h, a
corresponding plate i being also-bolted on to the opposite ends of such rods.
These sliding rods work through guide holes in the vertical standard B, and
bracket B', and are caused to slide longitudinally to and fro upon the surface
of the table A by the action of the vertical slide U through the intervention of
the link l, which is jointed at one end to a lug in the back of the slide, and at
the opposite end to another lug in the plate i. On the interior of the front
plate g there is secured or formed a projection m, which operates against the
front one of the two moulding jaws, the opposite jaw e¹ being acted upon by
a wedge or inclined projection m', fitted to or formed on the face of the vertical
slide U..
Each of the operating cylinders is constructed in the manner shown by
the sectional detail, Figure 5, with a view to cushioning the pistons aud
arresting their further ascent before reaching the top covers. This I accom-
plish by bringing the upper steam port n into the cylinder some distance
below the top cover so as to leave a steam space above the piston after it has
cut off the steam by covering the port. Round the interior of the cylinder I
form a separate series of steam ways o, o, which establish a communication
between the upper and under sides of the piston when elevated, the distance
between the upper and lower ends of such passages should be rather greater
than the thickness of the piston, and the upper ends of these passages o should
be a little above the upper edge of the steam port n, as shewn in Figure 5.
The effect of this arrangement is that as the piston is driven up by the
steam entering by the bottom port p it cuts off or arrests the escape of steam

page_text: through the upper steam port n and confines or imprisons a portion of the
steam above it in the space between the top of the piston and the cylinder
cover, such confined steam acting as a cushion. On the recoil, however, of the
piston a communication will be established between the upper and lower sides
thereof through the steam ways o, o, 'and a perfect equilibrium will be
obtained so long as the piston is not in operation, but on the admission of
fresh steam above the piston it will be forced down to its work, and when the
escape is opened it will rise again, and its course will be arrested as before
described just before reaching the cover of the cylinder. It is obvious that
the steam ways o, o, may be advantageously employed in the cylinders of
steam hammers and other like double-acting steam forging machines..
Having set forth the general construction of my improved machinery or
apparatus for shaping and forging metals, I will now proceed to describe
its mode of working when forging "tees," "elbows," and the like pipe
fittings. The flat plate or suitably shaped blank having been suitably heated
for forging is bent into the rough form of a "tee," "elbow," or." cross," by a
shaping or bending machine after the manner described in the Specification of
the Patent herein-before referred to; the partly formed article is. then
reheated to a welding heat in a suitable heating furnace and is placed in the
hollow of the mould block r in the positions shown in Figures 3 and 4; the
three mandrills k³, and k, k, are then caused to approach or converge simul-
taneously and enter the ends and vertical portion of the "tee" (see Figure 4);
this action of the mandrills is produced by lifting the handle L, whereupon
steam is admitted above the piston in the cylinder E, forcing it downwards in
company with the slide U and mandrill k². The upper pair of pins d, d, in
the slide U by acting upon the levers Y', Y', cause the horizontal slides W to
approach, carrying with them the mandrills k, k. A shoulder or collar is
formed on each of these three mandrills, which serves to square up
the ends
of the three arms of the "tee," as will be clearly seen on referring to
Figure 4. Whilst this action is going on the descent of the slide U also
brings into operation the hinged moulding jaws or clams e, e¹, (Figure 3,)
causing them to close upon and firmly grip the exterior of the forging,
thereby imparting the proper shape or finish thereto and holding it firmly
whilst the two edges of the blank are being welded together by the welding
dies or tools c, c, as I shall presently explain.
In Figure 2 have represented the slide U in its lowest position, but in
Figure 8 I have shown in red lines the same slide in its highest position.
On referring to these Figures it will be seen that as the slide descends the
link by assuming a more horizontal position forces the sliding frame h, g, i;

page_text: in the direction. of the arrow. in Figure 3, thereby causing the projection m
to press against and close the front jawe at the same time that the descent of
the wedge or inclined projection m¹, fast on the slide U, closes up the corres-
ponding jaw e. Whilst the forging is being thus firmly gripped between the
internal mandrills k, k³, and external jaws or clams e, e', the welding tools c, c,
are brought into operation by depressing the lever handle M, and thereby
admitting the. steam simultaneously above each of the pistons in the
cylinders F, F. These tools c, c, operate upon the exposed portion of the
forging between the edges of the closed jaws e, e¹, and are so shaped as to
enter the angle at the junction of the vertical with the horizontal branches of
the "tee," and to fit accurately round such portion of the forging as is exposed
between the two upper edges of the closed jaws. The forging having been
thus completed a reverse movement of the handle L effects the instant release
of the article by simultaneously withdrawing the three mandrills and opening
the jaws e, e, when the forging is removed and a fresh blank introduced.
I have only considered it necessary to describe and illustrate the mode of
producing "tees," as it will be obvious to the practical man that by suitably
modifying the shape of the mould block and jaws, and using one or both
the horizontal mandrills k, k, as the case may be, "elbows," "crosses," and
other like forgings may be equally manufactured in this machine.
Although I have described the direct application of steam to the working
of the shaping and forging instruments I do not confine or restrict myself to
that mode of operation, as other elastic fluids may obviously be employed, such
as compressed air or non-elastic fluids, such as water, either directly or
indirectly, or the requisite power may be derived indirectly from manual
labor.
Having now described and particularly ascertained the nature of my said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe, in conclusion, that what I consider to be novel
and original, and therefore claim as the Invention secured to me by the
herein-before in part recited Letters Patent is,―
First, the general construction and arrangement of machimery or apparatus
for shaping and forging metals, substantially as herein-before described.
Second, the application and use to and in the shaping and forging of metals
of moulding jaws or clams e, e¹, operating substantially as herein-before
described.
Third, the system or mode of shaping and forging pipe fittings, known as
"tees," "elbows," "bends," "couplings," and "crosses," and other metallic
articles susceptable of being so shaped and forged by the employment of a

page_text: mould block, in combination with moulding jaws or clams, converging dies,
and mandrills actuated by steam, water, compressed air, or manual power,
substantially as herein-before described.
Fourth, the peculiar arrangement of steam port and ways in the cylinders of
double-acting steam hammers and forging machines, substantially as and for
the purpose herein-before described and illustrated by Figure 5 of my
Drawings.
In witness whereof, I, the said Robert Mitchell, have to this my
Specification set my hand and seal, the Ninth day of February, One
thousand eight hundred and sixty-seven.
ROBERT MITCHELL. (L.s.)