Improvements in or relating to the Manufacture of Hollow Bodies of Cement, Gypsum, and other similar Materials.
Year: 1894

page_text: Date of Application, 30th Mar., 1894—Accepted, 11th Aug., 1894
COMPLETE SPECIFICATION.
Improvements in or relating to the Manufacture of Hollow Bodies
of Cement, Gypsum, and other similar Materials.
I, JOHANNES FRANZ KLEINE of 19 Julius Strasse, Essen on the Ruhr, Prussia, in
the Empire of Germany, Builder and Architect 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 :—
For manufacturing hollow bodies having the shape of plates or other forms
several processes have hitherto been employed, to which many defects are inherent.
The hollow spaces are formed by means of solid core pieces, which in part are very
smooth and tapering, in part covered with a coating of fat or with a hose or sleeve
or the like. But in withdrawing such cores, the work is frequently more or less
damaged. The manufacture of hollow bodies having a curved shape or of
considerable length or of larger width at some parts than others or having the shape
of bottles or pears and the production of similar hollow spaces has been hitherto
generally impossible or if possible offered particularly great difficulties and resulted
in a large number of defective pieces. These above-mentioned disadvantages are
entirely obviated by the hereinafter described process.
For manufacturing hollow bodies having a plane, curved or other suitable form,
1 use inflatable cores, tubes or vessels provided at one end or both ends with closing
or stopping devices i. These inflatable cores are filled with air or suitable liquid h
or with other similar substances. As soon as the inflatable cores are filled and the
stop devices are closed, so that the contents of said cores are prevented from
escaping, the cores being very strong may be used for forming the hollow spaces in
the bodies to be manufactured. Any desired shape may be given to these cores by
means of suitable movable pieces mounted within them, as shown by way of
example in cross section Figure 5, where the core a has fastened to it metal
lugs b, to which are secured movable arms c, the movements of which are
regulated by means of tension chains or equivalent d.
For manufacturing articles with hollow spaces having the shape of a pear or
bottle or any other similar form only inflatable cores having a corresponding
suitable shape are needed. If in addition to the closing device a suitable safety
valve is applied, this process may be used also, when hot or glowing casting
masses, such as asphalt, liquid metal, glass or the like are employed. Any
moulding box corresponding to the desired shape of the hollow body to be
manufactured may be employed; for producing hollow plates a box may be used
for instance as shown in the Figures 1 to 3 of the accompanying drawing;
Figure 1 being a horizontal section.
Figure 2 a longitudinal section, and
Figure 3 a cross-section of the said mould.
The closures e are provided with corresponding openings f for introducing the
inflatable cores a.
For manufacturing pipes or the like, a moulding box may be used such as
illustrated by way of example in the Figure 4 in cross section.
As soon as a inoulding box of proper shape has been prepared a sufficiently
large quantity of material m is applied to or cast upon the plane or curved base as
is necessary for manufacturing the body up to the lower border of the hollow
spaces to be manufactured. The inflatable cores are then introduced through the
openings arranged in the front walls and placed in proper position. The inflation
of the cores may be effected prior to or after their introduction. The rest of the
necessary mass may now be introduced into the mould and the hollow bodies may

page_text: be finished. Suitable metal pieces may be embodied with the mass in proper time
during the formation of the hollow body.
When the mass has sufficiently hardened, the stop devices i are opened, so that
the contents of the cores are allowed to escape; the cores will then collapse, and
may thereafter be readily withdrawn. In employing inflatable cores made from
suitable material this will offer no remarkable difficulties, even should the hollow
spaces have a form several times or only simply curved, or of irregular or bottle-
shaped formation or of correspondingly great length.
By making use of the above described process an extraordinary result is attained
in the production of hollow bodies. The process is very simple and requires no
expensive devices. The very considerable friction unavoidable in withdrawing
solid core pieces tightly surrounded by the walls and the deformities or the like,
which easily occur and produce more or less damage are entirely obviated in this
process. The production of defective pieces is as nearly as possible quite avoided.
The hollow bodies manufactured according to this process by reason of the intimate
coherence of the molecules or parts thereof not being disturbed by friction and
displacement, are of considerably greater strength and reliability than those of
ordinary construction.
Owing to the simplicity and safety of the process and to the reduction of the
work involved in the production and of the material used the manufacture of
hollow bodies according to this invention is essentially cheaper than by other
processes.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I declare that what
I claim is ;-
spaces
1. A process of manufacturing hollow bodies characterised by the application of
inflatable cores filled with air gas or liquid or the like for forming the hollow
which cores after the moulding material has been filled in or cast and sufficiently
set may first be deflated or emptied and then withdrawn from the mould without
damaging the hollow body substantially as described and illustrated in the
accompanying drawings.
2. In the manufacture of hollow bodies with the aid of cores capable of being
inflated and deflated shaping the cores by means of suitable movable pieces
mounted within the interior of the cores substantially as described and illustrated
in the accompanying drawings.
3. The combination with a hollow inflatable core of arms and chains or equivalent
such as c d substantially as described.
Dated this 30th day of March 1894.
W. P. THOMPSON & BOULT,
Agents for the Applicant.