Improved Apparatus for the Manufacture of Pipes or Tubes.
Year: 1893

page_text: Date of Application, 9th Sept., 1893-Accepted, 14th Oct., 1893
COMPLETE SPECIFICATION.
[Communicated from abroad by die Firma FRIED. KRUPP, Grusonwerk, of
Magdeburg-Buckau, in the Empire of Germany, Manufacturers.]
Improved Apparatus for the Manufacture of Pipes or Tubes.
I, HENRY HARRIS LAKE, of the Firm of Haseltine Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, 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 improved apparatus of a very simply construction for
the manufacture of pipes or tubes from ductile materials, the said apparatus being
intended more especially for the manufacture of lead pipes. Like other presses
heretofore used for making pipes; the said improved apparatus operates to press
the material, from a cylinder, by means of a piston or ram adapted to move in the
said cylinder, through an annular orifice which is defined interiorly by a cylindrical
or conical mandrel and exteriorly by the inner periphery of a die.
It differs however from pipe presses heretofore known or used in that the said
mandrel is stationary and extends centrally through the press ram which when in
operation slides along the mandrel. By this device there is effected a considerable
simplification in construction, and several advantages are obtained in the operation
of the press, as will hereinafter he set forth. .
The accompanying drawing represents in central longitudinal section a press
constructed in accordance with this invention, the ram being moved by hydraulic
pressure. A is an exchangeable die securely connected with the press cylinder B.
C is a mandrel the conical point of which projects centrally through said die.
The cylindrical shaft of the mandrel passes through the hollow ram D of the press
and in the construction shown is screwed into the base plate E of the press frame,
its lower part being provided with a screw thread to admit of adjustment as herein-
after described. The interior of the press cylinder B communicates through a
pipe F with a vessel G in which the lead is melted. H is an annular valve which
can be turned to close the thoroughfare F when required. The molten lead is
allowed to flow along the pipe F into the cylinder B until it fills said vessel up to
the level of the die Å. The annular valve H is then closed and the pressing may
commence.
In the apparatus shown in the drawing, the ram D is moved by means of
a hydraulic press which is arranged co-axially with the lead press below the same.
The shaft of the mandrel C extends through the ram I and the bottom of the
cylinder K of this press, in order that it may be accessible from below and be
turned by means of a wheel L secured thereon. By turning the shaft of the.
mandrel C the conical point of the mandrel may be raised and lowered and a larger
or smaller part thereof thus brought within the smallest part of the die. By this
means the mandrel is adjusted to produce pipes having a greater or smaller internal
diameter.
If it is not required that the mandrel be adjustable, its shaft may be fixed to the
bottom of the cylinder K instead of extending therethrough. In such case various
transverse sections of the pipes are obtained, by using dies, the inner peripheries®
of which may be of different diameters, and which may be situated higher or lower
with respect to the coned end of the mandrel to suit the requirements. Of course
it is not essential that a hydraulic press be employed for operating the ram D, as
for example for pipes of softer material a screw press or an eccentric press actuated
by hand or by suitable power transmitting gear will be sufficient.
The mode of operation of the press is as follows.
When the ram D moves upwards it pushes before it the block of lead situated in

page_text: the cylinder B round the shaft of the mandrel C, and causes the lead to flow and
issue from the annular opening between the die A and the mandrel. In this
manner is obtained a radial pressure, uniform in all directions, upon the shaft of
the mandrel, which centres the latter accurately and does not allow it to occupy
an eccentric position. This action is further aided by the fact that the lead pushed
upwards along the shaft of the mandrel tends to drag the shaft with it by friction..
Accordingly the shaft during the pressing operation is subjected to tension which
tends always to keep it straight.
A great advantage of the press arises from the fact that the interior of the
cylinder B remains completely shut off from the atmospheric air during the re-filling
thereof with fresh lead, as after each stroke of the piston both the mouth piece of
the press and also the joints between the press ram D on the one hand and the
cylinder B and the shaft of the mandrel C on the other hand are hermetically
closed by the lead which is pressed therein by reason of the great pressure, to which
it is subjected, and the ram D need never be withdrawn completely from the
cylinder B, as in other presses, in order to permit of the re-filling. The air
contained in the melting vessel G escapes upwards in the melting process, and the
liquid lead, the level of which lies in line or nearly in line with the die A, before
each fresh stroke of the ram, passes, free from air, into the press cylinder in which a
vacuum is produced, so that the pipes made by this apparatus are very homogeneous.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me
by my foreign correspondents, I declare that what I claim is:-
1. A pipe press having a stationary press cylinder carrying the die, a stationary
mandrel co-axial with said die, and a ram which surrounds said mandrel and slides
thereon when in operation, for the purpose specified.
2. A pipe press having a stationary press cylinder rigidly connected with a
melting vessel, and a thoroughfare forming a communication between said vessel
and cylinder whereby air is continuously excluded from the press cylinder, sub-
stantially as, and for the purpose, specified.
3. A pipe press having a stationary press cylinder carrying the die, a stationary
mandrel and a ram which moves relatively thereto, arranged in combination with
a melting pot communicating in such a manner with the cylinder that air is kept
continuously excluded therefrom, all substantially as, and for the purposes,
specified.
4. A pipe press constructed substantially as described with reference to the
accompanying drawing and operating as, and for the purposes, specified.
Dated this 9th day of September 1893.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.