A Process for Producing Weldless Hollow Objects (Tubes) Direct from a Solid Block.
Year: 1893

page_text: COMPLETE SPECIFICATION.
A Process for Producing Weldless Hollow Objects (Tubes) Direct
from a Solid Block.
We, JULIUS WÜSTENHÖFER of Arnsberg and WILHELM SURMANN of Barop
in the Province of Westfalia, Germany, Engineers, 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 :-
i
It is a well known fact that, when a pliable, plastic material of sufficient'
softness and having the necessary firmness and cohesive strength is made to
rotate very rapidly under pressure, and receiving at the same time an axial or:
linear movement, which is retarted by some brake action, a regular tube will be
formed from such a solid block.
By the process known as Mannesmann's method the said result is attained by
placing a heated steel block into a rolling mill, in which the axes of the rollers
lie crossways to each other and which are turned in the same direction, and which
are so shaped, that they grasp the block between them, turning and advancing
it lengthways at the same time, while a part of the rollers forms an obstacle
against the advancing motion of the approaching material.
The working here is a continuous rotary one, and because the forces act partly
against each other, there is of course a great amount of power required in this
process, a great deal of which however is wasted or spent in overcoming the
forces acting in opposition to the positif production of the tube.
"
We aim at and attain the same result without the rolling process, proper, that
is to say, without using continuously rotating rollers and without using con-.
tinuously acting tools for producing the rotating and axially advancing motion
of the piece of work.
By means of the annexed drawings we will proceed to explain our new process.
of making weldless tubes direct from a solid block.
We use prismatically shaped working plates, which may be called shift-plates
or "jack-plates," receiving a very quick to and fro motion and between which
the metal block is held. The jack plates are placed and moved crossways to
each other at an angle which may vary from 0 to 90 degrees. They are pressed.
upon the block between them, the one upwards, the other downwards in such a
manner, that when they make their movement backwards the pressure upon the
block is relieved in order to prevent the reversing and working back of the block.
From the description given, it follows that the block put between the two
jack plates will be turned round its own axis, but also that, at the same time,
it will be pushed forwards in the direction of its axis of rotation, because the
jack plates act crossways to each other.
The speed at which the plates are moved over and under the block is
thereby divided into one that causes the rotation, and into one that causes the
advancing movement of the block in the axial direction. Now if a be the angle
in which to two jack plates cross each other the two complementary speeds will
be v. cos. x and r. sin. ; the latter being the one that pushes the block forwards
in an axial direction, the other causing the turning.
If the speed of the jack plates be kept constant, the rotary motion or the
advancing motion of the block may be varied at will by changing the angle x
at which the plates cross. each other.
It is of importance to give the jack plates as great a speed as possible.
These plates may be guided in grooves of a suitable frame and their to and fro

page_text: motion may be effected by the ordinary crank and connecting rod mechanism or by
an eccentric or by any other device found suitable.
The block may be kept in proper position by the use of guide rollers which are
slightly pressed against it, so that its central axis will always be kept centrally
to the pressing surface of the jack plates, that is to say, so, that its geometrical
axis will always be in the plane of the diagonal of the parallelogramm formed.
by the projections of the side edges of the two plates.
The block may be held between center punches, which are adjustable. The
one on the side where the tube is formed, must be mounted in brackets or
bearings which can be shifted in the direction of the linear motion of the
advancing tube, and it serves then as a mandril over which the tube is formed.
This mandril itself does not move lengthways, only the bearings carrying it, so that
in making a long tube, they can make room for the tube. It is to be recommended,.
that the mandril receives a rotary motion in order to prevent the tube to sit fast
upon the mandril.
Instead of using only one jack plate on each side of the block, two placed parallel
side by side may be arranged above and below the block.
We also can arrange the jack plates oscillating round fixed pivots or shafts
placed crossways, instead of moving them in straight lines, and they are then of
course curved according to the radius of the circle prescribed by their working
faces.
The jack plates receive the shape shown in Fig. 1 of the drawing, forming a long
rectangular prism having a part of one of its sides cut slightly oblique or bevilled,
as at A; the other part B being quite smooth and lying horizontal or in the
direction of the movement of the plates. The bevilled part of the plates is placed
towards the entrance side of the block D, between the plates E & F; it is made
rough like the first cut of a file without cross cuts; it serves, so to say, in place of
the "roughing rolls." The smooth parts B take the place of the "finishing rolls"
in a rolling mill; they give to the tube produced a smooth and even surface.
C is a groove for guiding the plates in a frame.
The Figures 2 to 4 show the arrangement of the jack plates with the block
between them; the three figures being respectively a front and side view and a view
seen from the top, and the Figures 5 and 6 are two vertical sections in the direction
of the axis of the tube and at right angle to it. From Fig. 5 it will be seen that
the roughing part of the plates first makes an impression into the soft material,
causing a shoulder to be formed in the face of the plate and causing the plates
themselves to take hold of the material of the block and turn it round, the rough
parts A taking the hold, whereas the smooth parts B make the surface quite even
and smooth under their pressing and sliding or shifting action.
Figure 7 shows the use of a center-punch and of a mandril over which the tube is
formed. The mandril G receives a rotary motion, and its bearings H, H are so
mounted upon their bed, that they can be shifted lengthways, so that when long
tubes are made, the bearings can be pushed out of the way.
Instead of being guided over a mandril the block may be carried by rollers I,
supporting it sideways, as shown by Fig. 8.
Figures 9, 10 & 11 show the arrangement of double jack plates placed side by side.
The one pair L & L' working as roughing plates, the other pair M, M¹ finishing
the product.
In Figures 12 & 13 we show the jack plates arranged so, that they oscillate
round pins or pivots O & O¹, which lie crossways to each other; the working faces
of the "plates" in this case of course are circular and not straight, but they work
in other respects quite like the straight plates and they turn the block O¹ in one
direction and they cause at the same time its axial motion, whilst on their way back
their pressure upon the block is relieved.
The block may be guided here also on a mandril or on guide rollers as before.
The jack plates may also be made either in wedge shape themselves, or they may
be carried in oblique guides and then a conical tube is formed.

page_text: 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:
A process for making weldless hollow articles (tubes) from a solid block, which
consists in causing a hot or cold malleable metal block to be brought into quick
rotation and into a longitudinal motion at the same time, by pressing upon it, when
being moved one way, two or more "jack plates "which may be straight and
moving then in a linear direction, or curved and having then a circular motion,.
and which are arranged so, that they cross each other in in any angle between
O to 90 degrees. These jack plates being roughened at the entrance side of the
block and smooth at the exit side of the block or the tube formed respectively.
Dated this 24th day of December 1909,
J. WÜSTENHÖFER,
W. SURMANN,
Per Karl J. Mayer,
Agent.
J. WÜSTENHÖFER,
W. SURMANN,
Per Karl J. Mayer,
Agent.