Improvements relating to the Manufacture of Piping, Rods, and other Articles of Lead and similar Metals, and to Apparatus therefor.
Year: 1892

page_text: Date of Application, 31st Mar., 1892
Complete Specification Left, 2nd Jan., 1893-Accepted, 30th June, 1893
PROVISIONAL SPECIFICATION.
Improvements relating to the Manufacture of Piping, Rods, and
other Articles of Lead and similar Metals, and to Apparatus
therefor.
We, WILLIAM CLARK, of 34, Paget Road, Plumstead, in the County of Kent,
Engineer, and HARRY ANDREWs, of The National Liberal Club, Whitehall Place,
in the County of London, Engineer, do hereby declare the nature of this invention
to be as follows:-
Our invention is designed to simplify the manufacture and improve the quality
of piping, rods and other articles made of lead and similar metals, and to reduce
the cost of such manufacture.
In the manufacture of lead rod and lead piping as hitherto practised, the molten
metal is run into a pressing cylinder or retainer and allowed to cool sufficiently to
become set, with all the slag or dross upon the top thereof; the lead is then forced
through a die or dies by hydraulic or other power. As the metal is set or in a
solid state before it is forced from the pressing cylinder through the die or dies,
very great pressure is required for this purpose. Moreover the slag or dross is
liable to become intermingled with the pure metal and to be forced therewith
through the die or dies, thus forming imperfect rods, pipes or other articles.
But, by our invention, we greatly diminish the pressure required in the
manufacture of lead rod, lead piping or the like, and we provide for causing the
flow of only pure metal under pressure through the die or dies, all the slag or dross
remaining on the surface of the molten mass, whilst the metal to be forced through
the die or dies is taken from the molten mass below the surface thereof.
Our said invention comprises an improved method of making lead rod, lead
piping and similar articles, in which method, instead of allowing the metal to set in
the cylinders or chambers in which it is be subjected to pressure, we allow the pure
molten metal from the lower part of a body or mass thereof to flow into the said
cylinders or chambers, and force it therefrom, while in a molten condition, through
one or more tubes or dies; we reduce the temperature of the metal during its
passage through such tubes or dies, sufficiently to cause it to set, and, by continuing
the pressure in the said cylinders or chambers, we further compress and consolidate
the metal by forcing it through one or more taper or conical tubes or dies forming
extensions of the aforesaid tubes or dies.
Our said invention, moreover, comprises the construction of the apparatus with
one or more pressing cylinders provided with rams or plungers and so arranged in
a pot, trough or other vessel for containing the molten lead, that the said cylinders
may be kept entirely covered and surrounded by the molten metal. These pressing
cylinders are provided with apertures for the admission of the molten metal thereto,
which apertures are closed at the proper time either by cocks or valves or by the
said plungers; and the said cylinders communicate with suitable tubes or dies for
the purpose above mentioned.
Our said invention also comprises other improvements hereinafter mentioned.
In carrying into effect our improved method of manufacture, we find it
advantageous to employ an apparatus constructed with a pressing cylinder arranged
near the bottom of a melting pot so that the said cylinder is, as above mentioned,
entirely covered and surrounded by the molten metal. The said cylinder has a
cock or valve whereby communication may be established between the molten metal
in the melting pot and the interior of the pressing cylinder. The said cylinder is
also provided with a ram or plunger, the external diameter of which should be
somewhat smaller than the internal diameter of the cylinder, so that there will be a

page_text: suitable clear space all around the said ram or plunger between the same and the
wall of the cylinder. The end of the cylinder through which the ram or plunger
works, is made to fit the latter, and is provided with a gland packed with asbestos
or other suitable material. A portion of the said cylinder near the gland, and the
opposite end of the melting pot are surrounded by cold water, whereby leakage of
the molten metal is prevented, such metal being cooled and set before it can pass
out of the cylinder through the joints. The ram or plunger is preferably made
hollow and has a water-pipe fitted therein at one end and reaching nearly to the
other, and giving a constant supply of cold water that keeps the inner part of the
ram or plunger always cool, the water being discharged through the end of
the plunger outside the cylinder. At the discharging end of the cylinder is fitted
a steel tube or die which extends through a vessel containing water, whereby the
metal is cooled in its passage through such tube or die. The inside diameter of
this tube or die is larger than the desired diameter of the rod or other article, and
a suitable taper die of the required size is attached, by screwing or otherwise, to
the outer end of the aforesaid tube or die.
In using the machine, the metal in the melting pot is kept in a molten condition,
and metal is supplied to the said pot so as to always keep the cylinder below the
surface of the molten metal therein. When the ram is at the end of its outward
stroke, the valve is opened to permit communication between the molten metal in
the melting pot and the interior of the cylinder. In the backward movement of the
the molten metal rushes in to fill the empty space in the cylinder. When
the ram comes to the end of the inward stroke, the valve is instantly closed, leaving
the cylinder full of molten metal. As the ram advances, the liquid metal is forced
into the tube or die, where it becomes set by reason of the reduction of its
temperature by the cold water. In its set condition, it is compressed and forced
through the aforesaid taper die, thus producing the finished article.
ram,
By this improved method of manufacture we can do the work required, with a
smaller expenditure of power than heretofore, as we only require to exert the
necessary pressure upon the sectional area of the article being made, and we do
this while the metal is in the most favourable condition for being worked.
We can, if desired, use hydraulic power for operating the ram or plunger. As,
however, a comparatively small force is required for this purpose, it is more
convenient, in many cases, to employ gearing driven by belts or bands or otherwise
from a suitable motor, and working by means of a screw or a rack and pinion. In
such cases, we sometimes provide a sliding bar arranged to be operated auto-
matically to reverse the motion of the gearing, and to simultaneously open or close
the admission-valve of the pressing cylinder as required. We sometimes use a
weighted lever for obtaining a more rapid movement of this sliding bar.
In some instances, we combine, with a single melting pot and set of dies,
several pressing cylinders so arranged that the forcing of the metal into and
through the said dies may be carried on continuously under a uniform head or
pressure.
We find it advantageous to make the melting pot with an inclined bottom, the
cylinder or cylinders being arranged at the deeper end thereof, and to provide
suitable means for applying heat, to the said melting pot, for the purpose of
maintaining the metal in a molten state.
Instead of using a valve on the pressing cylinder, we sometimes form an aperture
near the rear end thereof, so that, when the plunger is moved back to the end of
its stroke, the molten metal will enter the cylinder through such aperture, and the
plunger, in the first part of its forward stroke, will close the said aperture.
We prefer that the return stroke or travel of the ram or plunger should be
effected more rapidly than the forward stroke thereof, and we usually arrange the
gearing so as to obtain this result.
The above mentioned method of preventing leakage of the molten metal at the
joints and between the relatively movable parts, by cooling and solidifying such
metal before it can escape, is an important feature of our invention, as great

page_text: difficulty has hitherto been experienced in forming joints in such a manner as to
prevent the passage of molten lead through the same.
Dated this 31st day of March 1892.
D. YOUNG & Co.,
11 & 12, Southampton Buildings, London, W.C.,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements relating to the Manufacture of Piping, Rods, and
other Articles of Lead and similar Metals, and to Apparatus
therefor.
We, WILLIAM CLARK, of 34 Paget Road, Plumstead, in the County of Kent,
Engineer, and HARRY ANDREWS, of The National Liberal Club, Whitehall
Place in the County of London, Engineer, 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 :-
Our invention is designed to simplify the manufacture and improve the quality
of piping, rods and other articles made of lead and similar metals, and to reduce
the cost of such manufacture.
In the manufacture of lead rod and lead piping as hitherto practised, the molten
metal is run into a pressing cylinder or retainer and is allowed to cool therein to
such a degree that it becomes set, with all the slag or dross upon the top of the
mass, the solid or congealed lead is then forced through a die by hydraulic or other
power, a mandrel being placed in the axis of the said die when it is desired to
manufacture lead pipe. As the metal is set or in a solid state before it is forced
from the pressing-cylinder through the said die, very great pressure is required
for this purpose. Moreover, owing to the manner in which the pressure is
applied, the slag or dross is liable to become intermingled with the pure metal
and to be forced therewith through the die, thus forming imperfect rods, pipes
or other articles.
But, by our invention, we greatly diminish the pressure required in the manu-
facture of lead rod, lead piping or the like, and we provide for causing the flow
of only pure metal under pressure through the die or dies, all the slag or dross
remaining on the surface of the molten mass, whilst the metal to be forced through
the die or dies is taken from the molten mass below the surface thercof.
Our said invention comprises an improved method of making lead rod, lead
piping and similar articles, in which method, instead of allowing the metal to set
in the cylinders or chambers in which it is to be subjected to pressure, we allow
the pure molten metal from below the surface of a body or mass thereof to flow
into a cylinder or chamber, and force it therefrom, while still in a molten condition,
through one or more tubes or dies; these tubes or dies are kept cool, so that,
during the passage of the metal through such tubes or dies, the temperature thereof
is reduced, by contact with the cooled metal surfaces, sufficiently to cause it to
set; then, by continuing the pressure in the said cylinder or chamber, we further
compress and consolidate the metal by forcing it through one or more taper or
conical tubes or dies forming extensions of the aforesaid tubes or dies.
Our said invention, moreover, comprises the construction of the apparatus with
one or more pressing-cylinders provided with rams or plungers and so arranged in
a pot, trough or other vessel for containing the molten lead, that the said cylinders
may be kept entirely covered and surrounded by the molten metal. These
pressing-cylinders are provided with apertures for the admission of the molten
metal thereto, which apertures are closed at the proper time either by cocks or
valves or by the said plungers; and the said cylinders communicate with the
aforesaid tubes or dies for the purpose above mentioned.
Our said invention also comprises other improvements hereinafter described,
,

page_text: In the accompanying drawing we have shown how our said invention may be
conveniently and advantageously carried into practice.
Figure 1 is a plan,
Figure 2 a side elevation, partly in section on the line, x, Figure 1, and
Figure 3 an end elevation, showing one form of our improved apparatus.
Figure 4 is a longitudinal central section, and
Figure 5 a section on the line a¹, xl, Figure 4, showing one form of die and
mandrel, adapted for use in our improved machine when making lead piping.
Figure 6 is a longitudinal central section showing another form or modification
of the said die and mandrel.
Like letters indicate corresponding parts throughout the drawing.
A is a bed-plate on which is firmly secured a trough or melting pot B for con-
taining the molten metal as at B. This pot is heated in any convenient manner
to keep the metal in a molten condition. C is the pressing-cylinder arranged near
the bottom of the said melting pot B and partially enclosed therein. D is the ram
or plunger of the said cylinder. The internal diameter of that part of the cylinder C
which is enclosed in the melting pot B, is made somewhat larger than the external
diameter of the ram or plunger D so that a suitable clear space is left between
the two, thus diminishing the conduction of heat from the cylinder to the plunger.
The end of the cylinder C through which the plunger D works, is made to fit
the said plunger and is surrounded by a water-jacket C₁; the said cylinder is,
moreover, provided with a stuffing-box C packed with asbestos or other suitable
material. E is an open-bottom cock for admitting the molten lead into the
cylinder C from the trough or reservoir B. F is a steel tube extending through a
water-jacket G, and connected with the discharge-end of the cylinder C. H is a
slightly conical or taper tube or die for compressing and consolidating the metal
which has been shaped in its passage through the tube F. The inside diameter of
the tube F is made slightly larger than the desired diameter of the rod or other
article, so that the metal will be compressed and consolidated by being forced
through the said conical die H. Cold water is to be kept circulating through the
said jackets C¹ and G.
In the interior of the plunger D is secured a tube J for conveying cold water
supplied from any convenient source through the inlet J', to the forward end of the
said plunger, whence it passes back along the space between the tube J and the
inner surface of the plunger D to the outlet J2 through which it is discharged.
By these means the said plunger is kept cool during the working of the machine,
and the cylinder C being also kept cool by the water circulating through the
jacket C, any metal flowing between the closely fitting parts of the said cylinder
and plunger will be congealed or set, and the escape of the molten metal from the
cylinder will thus be prevented.
To prevent leakage of the molten metal at the joint between the cylinder C and
the water-jacket G, and also at the joint between the said cylinder and the tube F,
an annular groove or recess C³ is formed in the forward end of the cylinder, into
which groove or recess the water from the jacket G will enter, thus cooling and
congealing any molten metal that may enter between the screw-thread in the end
of the cylinder and the corresponding screw-thread on the end of the tube F. A
disc K of asbestos or other suitable packing is, moreover, placed upon the end of
the cylinder C between the trough or pot B and the jacket G, which is secured
to the said trough or pot by means of suitable screws or bolts. Around the end
of the cylinder is also placed a ring or annular piece L which bears against the
disc or packing-ring K. A space is left between the ring L and the interior of
the jacket G to allow the water in the said jacket free access to the said packing,
for the purpose of cooling and congealing any metal that may enter between the
exterior of the cylinder and the corresponding wall of the trough or pot B. The
water circulating through the jacket Ci serves to cool and congeal any metal that
may pass between the exterior of the cylinder and the other wall of the trough
or pot B. The cylinder C is secured to the said trough or pot by screws or

page_text: pot B.
བ-༦ ༠-ས ༦)TuūST in one piece with the trough or
a is a shaft arranged to be driven from any suitable motor by means of two bands
or belts running in opposite directions, one of which is arranged to drive the fast
and loose pulleys b, and the other to drive the fast and loose pulleys c¹, c. The
pulley bis keyed on the shaft a and on this shaft is also securely fixed a gear-wheel d.
This wheel is geared with another gear-wheel e of approximately the same diameter
which is formed with a larger gear-wheelf, these two wheels being screw-threaded
internally and working like a nut on a screw-shaft g secured to the plunger D, and
end wise motion of the said nut being prevented by the bearings g, g of the shaft g.
The pulley c is fixed on a sleeve which is free to turn on the shaft a, this sleeve
has fixed upon it a pinion which is geared with the wheel ƒ.
k is a sliding bar, working in guides and arranged to be actuated by means of
an arm or lug D' on the outer end of the plunger D, which, in the to-and-fro
movement of the said plunger, acts alternately upon shoulders
or pro-
jections k', k, on the said bar k. The said sliding-bar is formed with a slot 4³ into
which extends the lever or arm E of the valve or cock E, so that, in the to-and-
fro movement of the said bar, the said cock will be automatically opened and closed
as required. The sliding-bar is also provided with prongs or forks m for
transferring the driving-belts from the fast pulley to the loose pulley band from
the loose pulley e to the fast pulley c¹ and vice versa, so that reciprocating motion
will be imparted to the plunger D. To ensure rapidity of movement of the sliding
bark at the ends of its stroke or travel, we provide a weighted lever n which is
mounted on a shaft or pivot n' and is connected with the sliding-bar k in such a
manner that, when the said lever has been moved in either direction beyond its
vertical position by the action of the plunger D, it will fall by gravity and thus
rapidly complete the movement of the said sliding bar.
By the arrangement of the driving-gear as above described, we provide for
obtaining a quick return movement of the ram or plunger.
In using the machine, the metal in the melting pot or trough B is kept in a fluid
condition by the application of heat to the said pot or trough and is maintained at
such a level as to always cover the cylinder C, further metal being supplied from time
to time as may be required for the purpose. Assuming that the plunger D is at the
end of its forward stroke and that the valve E is open, thus connecting the interior
of the cylinder C with the pot or trough B, then, in the backward or return stroke
of the said plunger, the molten metal will be drawn into the cylinder until the said
stroke is completed when the valve E will be automatically closed and the motion
of the plunger simultaneously reversed by means of the sliding bark; in the
forward movement of the plunger D, the molten metal will be forced into and
through the tube F. wherein it becomes set by reason of the reduction of its
temperature by the cooling medium in the jacket G. In its set condition, it is
forced through the taper or conical die H and thus compressed, the finished rod or
other article being discharged from the said die H. At the end of the forward
stroke of the plunger, the valve E is again opened automatically and the above
described operations are repeated. The use of this taper or conical die is an
important feature of our invention as it ensures great density of the metal in the
finished article.
When making lead pipe in our improved machine we prefer to use a die M and
mandrel N as shown in Figures 4 and 5, the said die being adapted to screw into
the end of the pressing-cylinder C similarly to the tube or die F, Figure 2; the
aperture M' at the end of the said die M next the cylinder is made conical as
shown so as to receive the enlarged conical end N¹ of the mandrel N which is
accurately fitted therein. In order to permit the entrance of the lead into the said
die from the pressing cylinder the conical end N' of the said mandrel is provided
with longitudinal grooves N' through which the lead can pass into the space
between the die and mandrel. The die and mandrel may be made to correspond to
the dimensions of the finished article or they may be made slightly taper or conical

page_text: or a supplementary taper or conical die and mandrel may be used in conjunction
In the
with them, for the purpose, of compressing and consolidating the metal.
manufacture of lead piping we sometimes employ the arrangement shown in
Figure 6 in which a die M is formed on or screwed into the end of the pressing
cylinder as above described, but the mandrel, instead of being secured in the_end.
of the said die, is screwed into or otherwise attached to the end of the plunger D so
that it moves with the said plunger.
By means of our improved apparatus, the work can be performed with a smaller
expenditure of power than heretofore, as, in our machine, it is only necessary to
exert the pressure upon the sectional area of the article being made and we do
this while the metal is in the most favourable condition for being worked.
We can if desired use hydraulic power for operating the ram or plunger. As,
however, a comparatively small force is required for this purpose, it is more
convenient in many cases to employ gearing driven by belts or bands, from a
suitable motor, and working by means of a screw as shown, or by a rack and
pinion. Moreover we can employ other suitable means for automatically effecting
the reversals of motion of the plunger and the opening and closing of the cock or
valve at the proper times to admit the molten metal to and enclose it in the
pressing-cylinder.
In some instances, we combine, with a single melting pot and set of dies, several
pressing cylinders so arranged that the forcing of the metal into and through the
said dies may be carried on continuously under a uniform head or pressure.
We find it advantageous to make the melting pot with an inclined bottom, the
cylinder or cylinders being arranged at the deeper end thereof as shown in the
drawing, and we provide a furnace or other suitable means for applying heat to
the said melting pot for the purpose of maintaining the metal in a molten
condition.
Instead of using a valve on the pressing cylinder as shown, we sometimes form
an aperture near the rear end thereof so that when the plunger is moved to the
end of its backward stroke, the molten metal will enter the cylinder through such
aperture, and the plunger in the first part of its forward stroke, will close the said
aperture.
The above described method of connecting and packing the several parts of the
apparatus so as to prevent leakage of the molten metal at the joints and between
the relatively movable parts by cooling and solidifying such inetal before it can
escape is an important feature of our invention as great difficulty has hitherto been
experienced in forming joints in such a manner as to prevent the passage of molten
lead through the same.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
First. The manufacture of piping, rods and other articles of lead or similar
metal by a method such as we have hereinbefore described wherein the required
shape is imparted to the metal by first forcing it while in a molten condition
through a tube or tubes in which it is cooled sufficiently to cause it to set, and
then compressing and consolidating the metal by forcing it through a taper or
conical die.
Second. The improved method of manufacturing lead rod, lead piping or the
like, consisting in allowing the pure molten metal from below the surface of a
mass thereof, to flow into a cylinder or chamber, then forcing it therefrom, while
still in a molten condition, through a tube or tubes in which it is cooled
sufficiently to cause it to set, and then forcing it through a taper or conical die,
substantially as herein before described.
"
Third. An apparatus for the manufacture of lead rod, lead piping or the like,
which apparatus is so constructed that it operates automatically to alternately
draw the molten metal from a melting pot into a cylinder or chamber and force

page_text: the said metal, while still in a molten condition, from the said cylinder or chamber
through one or more tubes or dies in which it is cooled so as to cause it to
set before its discharge therefrom, substantially as herein before described.
Fourth. In an apparatus for the purpose above specified, the combination,
with the tube in which the metal is cooled and congealed, of a taper or conical
die whereby the metal, after being thus cooled and congealed, is compressed and
consolidated, substantially as herein before described.
Fifth. The plunger provided with the means for cooling the same, substantially
as, and for the purpose, above specified.
Sixth. The improved apparatus (with or without the taper or conical die)
constructed substantially as described with reference to the accompanying drawing
and operating as and for the purposes, above specified.
Seventh. The improved mandrel and die constructed and combined substantially
as described with reference to Figures 4 and 5 of the drawing for the purpose
specified.
Dated the and J 1902
D. YOUNG & Co.,
11 & 12, Southampton Buildings, London, W.C.,
Agents for the Applicants.