Process and Mechanism (Rolling Mill) for the Froduction of Boiler Pipes, Tubings, "Fighting" Masts for War Ships, Flame Tubes, and the like in One Piece without Seam.
Year: 1899

page_text: Date of Application, 28th Nov., 1899-Accepted, 10th Feb., 1900
CUMFLETE SIMULTICATION.
Process and Mechanism (Rolling Mill) for the Froduction of Boiler
Pipes, Tubings, "Fighting" Masts for War Ships, Flame Tubes,
and the like in One Piece without Seam.
I, OTTO KLATTE, Director of Mines, of 36, Goethestrasse, Düsseldorf, Germany,
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:
Various attempts have already been made to produce seamless boiler tubes
from a hollow body. In these attempts, the hollow body pushed on to the
upper roller was forced against the lower roller but slid nevertheless only between
the rollers, around the upper roller, and there was no "stretching," in other
words, thinning of the sides. The cause of this lay firstly in the insufficiency
as well as in the application of the pressure which was applied during the rolling
without the hollow body "gripping" " the rollers; further, in the circumstance
being overlooked that in rolling a hollow body as distinguished from a plate,
double pressure is requisite.
Although, at the present time, it is very easy to furnish the necessary pressure.
this is only effected by means of extensive and costly arrangements. The object
of this invention, accordingly, is to reduce the pressure necessary in the rolling
of boiler pipes, etc., to what is required, for a correspondingly large plate, that
is to one half, and to render it possible to regulate the pressure, as desired, as in
the case of plate-rolling, without its being necessary from time to time during
the rolling to stop the fluid pressure which can be combined with steam pressure
(hydraulic-steam multiplicator).
In plate-rolling, the roller (operative) is at constant trouble to bring the rough
slab, not parallel to its edge but always obliquely between the rollers, in order
not to bring the full pressure on to the entire plate at once, and to avoid
concussions. When, however, the entire plate has reached the rolling mechanism
the full power must be applied.
In inserting the plate between the rollers, a so called pointing of the plate
occurs, (as shown in Figure 1 of the accompanying drawing) and the rollers
overcome the mass that meets them. according to the pressure imparted.
As Figure 1 illustrates the insertion of the material in plate-rolling. Figures 2
and 3 show that the "gripping" of the rollers in the case of a "ring" is only
possible with double pressure, unless measures be taken for diminishing the
amount of pressure. In the case of a hollow body between the rollers and
taking part in the rotation around the roller, the " grip" is incalculably dis-
tributed over the whole circumference, so that it is hardly possible to determine.
by measuring. that there is any stretching. In order to properly "press in "
the hollow body when the rollers are stationary so that they may duly "grip" it,
double the pressure is likewise required as for a correspondingly large plate.
When the rolling mechanism however is stationary time is lost and the piece of
work cools more or less, so that a perfect rolling cannot be effected without
double heating.

page_text: "
3
The proper pressing in" of the hollow body whilst the rollers are stationary
is however, attended by the further disadvantage that it may be "pressed in
too deep and too great a mass come between the rollers, in which case the rollers
slip away from (or 'slide in advance of) the "towering' mass of the hollow
body, or the rollers, or other parts of the rolling mechanism, are broken.
In the case of a hollow body being overheated, a severance of the same may
occur if the pressure be too great.
66
For the purpose of obviating all these contingencies and disadvantages, one or
more longitudinal grooves are made in the hollow body, reducing the thickness
of the material nearly to that which it should be when finished, these grooves
correspond to the extent of the engaging point or grip" of the rollers. This is
effected, if the hollow body be cast, by suitably projecting ribs in the mould;
if it be driven over a mandrel, by means of projecting ribs on the mandrel and
in the form; and, if rolled, by projecting ribs in the middle point of the caliber
(at least in one roller) and on the fixed mandrel (Figure 4).
In the forward or length rolling; when the hollow body is rotated from time
to time on the mandrel bar to the extent of: 45°; it receives eight impressions
or grooves as shown in Figures 5 and 8; when cast or pressed however, only a
single or a double one, as may be desired (Figures 6 and 7). The production of
these impressions or grooves in the warm hollow body may also be effected under
a steam hammer by mortising, or in batches, or all at once, by means of a press
with a suitably formed stamp.
From Figures 2 and 3, it will be seen that the "gripping" surface in the
case of a "ring is twice as large as in that of a plate (Figure 1). The depth
of the impression depends upon the degree of pressure, the temperature, of the
hollow body and the density of the material. In plate-rolling, the pressure. is
regulated in the known manner by means of pressure screws worked with the
hand or by mechanism, the pressure being constantly reduced in proportion to
the increased density and cooling of the piece of work being rolled.
In the rolling of a
<<
ring," the pressure has hitherto been regulated according
to the resistance of the constantly cooling hollow body, it being possible with
this that the hollow body may slide.
Now, in order that the regulating of the pressure may be duly effected also
in the rolling of a ring," the pressure regulating contrivance shown in Figures, 9
and 10 in two examples is' employed. In both these, the regulating is effected
by means of two blocks or wedges seated in supports, these blocks being pushed,
backwards and forwards, or upwards and downwards against the seating of the
upper cylinder (roller) which is connected with the " pressure stamp" (piston of
compression). (It is obvious that the arrangement of the blocks is otherwise
when the rollers "exchange functions" with each other.)
The driving of the one arrangement is thus effected:-By means of bevel
wheels 53 operated with the hand or by a machine, the screws or worms 55 on a
shaft 54 are actuated and by gearing with worm wheels, 56 cause screws 57
which are in connection with a wedge or block 58, to move forwards and
backwards.
The upper roller 32 in connection with the piston of compression, together
with its bearing is "bounded" on both sides by the wedge or block 58, so that
it can only exercise such pressure on the hollow body, pushed on to the lower
mandrel roller, as is intended through the adjustment of the blocks or wedges.
The pressure is continued during the rolling and, as already mentioned, only
limited by the side-blocks 58.
The right hand drawing shows the same principle of limitation by blocks, but
in this case there is the difference that the side-blocks 62, which are also guided
in supports, or bearers, as the blocks 58, are not moved sideways, but upwards
and downwards by means of a shaft and screw 60, worm wheel 61 and, screws 621,
and regulate the pressure in the same manner.
The sidewards displacement or adjustment of the blocks is preferable."

page_text: The pressure can, however, also be limited by means of adjustable joints
arranged at the part where the rollers are situate; by horizontally placed tension
screws for adjusting the blocks; by eccentric seating; or, if the part into which
the rollers are situate be at the side of the tooth rod, by means of tooth wheels.
The process of regulating the pressure is as follows:-
When the hollow body, or hollow block, has been pushed on to the mandrel
roller, and so that one of the pressure grooves lies in the vertical "roller-middle,"
the suitable pressure is applied, in certain cases with the assistance of the
"steam-multiplicator," and after the block contrivance for regulating the bearing
has been brought into the desired position.
The upper roller now presses in the groove as may be desired, and as shown in
various positions in Figures 2 and 3.
In the case of a solid "ring" without any groove, the upper roller would be
forced to press into the recess 63, 64, 65, 66, whilst, in the case of a groove being
present would only be forced to press into the shaded spots (triangle) 63, 67,
and 66, 68. With inside and outside grooves in the hollow body, the cross
sections of the triangle are distributed uniformly above and below, the hollow
body in receiving the pressure bends upwards or straightens out before and
behind the roller, whilst in rolling, as soon as the rollers rotate, the upper roller
which is the larger one presses the ring" steadily downwards.
66
It is now made clear that the rollers are enabled to "grip" the hollow body,
which, in rolling without a groove, it is very difficult to ensure.
When the rollers have turned the hollow body, furnished with a groove, once
round, or in other words, stretched it, the hollow body would slide, if the blocks
held back the upper pressing roller. Consequently, the blocks are withdrawn,
or lowered, during the rolling. If, now, a groove enters the vertical "rolling-
middle," the upper roller, which is under pressure, is pushed to the next indicated
limit.
This process is repeated until the piece of material to be rolled has the necessary
thickness.
Figures 5 to 8 are views in cross section of a "ring" with a single, double, or
several double grooves.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
1. A process for the production of boiler pipes, tubings, and the like, according
to which the hollow body to be drawn out in a plate rolling mill is previously
furnished with one or more outer or inner or outer and inner longitudinal
grooves, as preferred, and in a suitable manner, which reduce the material of
the hollow body in the particular spots, until it is of the thickness required when
finished, for the purpose of facilitating the "grinping" of the rollers.
2. For carrying out the process according to Claim 1. a plate rolling mill, in
which the bearings for the pressure roller are arranged so as to be vertically
adjustable and the "forward pushing " of this roller is limited by blocks, or
wedges, with working surfaces corresponding. or co-operating, with those of
the bearings, and adjustable automatically, or with the hand. by means of suitable
mechanism, for the purpose of precisely regulating the pressure.
Dated this 28th day of November 1899.
H. GARDNER,
Patent Agent, 166, Fleet Street. London,
Agent for the said Otto Klatte.