Improvements in Blanks for Making Conical Tubes.
Year: 1899

page_text: Date of Application, 13th Feb., 1899-Accepted, 24th June, 1899
COMPLETE SPECIFICATION.
Improvements in Blanks for Making Conical Tubes.
I; EMIL BOCK, of Oberhausen, Rhenish Prussia, Germany, Mechanical 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:-
For making conical wrought iron or steel tubes and masts, hollow blanks are
required, having parallel sides outside and a conical hole inside.
The casting of such blanks, as hitherto done causes considerable difficulties,
because the core in the mould, forming the hole in the blank, being strongly
tapering, when made of metal very easily melts away and when made of sand has
the tendency to stick to the metal cast around it This happens because just at
this place a great mass of hot metal is accumulated in the mould.
I avoid this by making the blanks in the following new manner, which I shall
describe hereafter by means of the annexed drawing, in which
Figure 1 shows a vertical section of the mould with the core shown therein for
casting the blank;
Figure 2 is a top view of Fig. 1;
Figure 3 is a cross section along line I-I of Figure 1;
Figure 4 is a view seen from the bottom;
Figure 5 is an outside view of the blank produced in the mould Fig. 1-4;
Figure 6 is a similar view seen at right angle to Fig. 5;
Figure 7 is a vertical section along line II of Fig. 6;
Figure 8 is a vertical section along line II-II of Fig. 5
The hollow space of the mould A is of uniform width in one direction, but it
varies in width and shape in the vertical direction to the first, as seen from
Figs. 2, 3 and 4, being of nearly rectangular form at the bottom (Fig 4) getting
gradually thinner or narrower towards the upper side (Fig 2) and having the shape
of a central wider part B with thin wings C right and left at the top side
The core placed in the center of this mould (chill) is on the whole of oblong
or elliptical shape, tapering towards the top, where its section is circular.
The blank cast in such a mould is of equal width from bottom to top in one
direction; the sides a b, a b being parallel to each other, but in the other direction
its thickness and its shape varies, getting gradually thinner, the sides cd, cd
converging towards the upper end, while right and left of the central part the thin
wings C are formed so that the blank contains less metal in the top part than in
the bottom part, approximately in the same ratio as the body of the core
diminishes. The cast or molten metal therefore will cool down soonest at that part
where the core is smallest and I thus attain that the core, when of metal, will not
be molten down, or when of sand, will not be cast and stick together with the
metal cast arround it. The blanks cast in the shape shown and described and by
means of the moulds shown, when rolled out flat, form a long strip composed, as it
were, of two plates placed one above the other and welded together at the sides but
separated in the middle, where a wedge shaped or trapezoidal slit is formed, the

page_text: partition slit between the two sides will be of more regular shape than when made
by the old method; the edgelines of the tapering slit are more rectilinear.
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
Making hollow blanks to be used for making conical tubes or posts, said blanks
having uniform width and parallel sides in one direction and varying in shape and
thickness in the other direction, so that the volume of metal cast round the oblong
conical core in the middle of the blank, diminishes approximately in the same ratio
as the volume of the core, which was used for forming the hole in the blank, the
whole as described and illustrated and for the purpose set forth.
Barmen, this 26th day of April 1899.
EMIL BOCK,
Per Karl J. Mayer,
Agent.