Improvements in Building Blocks applicable for Cavity Walls.
Year: 1899

page_text: Date of Application, 2nd Nov., 1899-Accepted, 16th Dec., 1899.
COMPLETE SPECIFICATION.
Improvements in Building Blocks applicable for Cavity Walls.
I, LUDWIG FINK, of Eden-Oranienburg, in Prussia, Electrician, 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:
In buildings that stand alone country houses and other buildings it is usual
to construct the outer walls double with an air cavity between in order to secure
a dry interior. The customary building bricks are ill adapted for this construc-
tion since they are inconvenient to use as cross-connections and allow of no changes
in the distance apart of the two walls.
The building block here described in detail and represented in the accompanying
drawing is intended to obviate these inconveniences and to bind firmly together
the single blocks as well as the two walls.
In elevation the block has the shape of a rectangle with dove-tail shaped pro-
jections on both the verticle sides, which when they are built together leave
an open space between each two as in Fig. 1 at a.
In erecting the double wall care is to be taken that the corresponding open
spaces in the two walls are directly opposite to each other.
In each pair of corresponding openings of the parallel walls there fits a connect-
ing piece of prismatic form or the shape of the section of which is determined
by that of the opening left by the dove-tail projections, and by which the latter
are held firmly together. By lengthening or shortening these connecting pieces
the space between the two walls may be varied at will.
The shape of the building block allows either of the separate layers breaking
joint vertically, as is shown in the lower half of Fig. 1, or of the joints being
over one another in a vertical line, as is shown in the upper half. In the latter
case two connecting pieces would have to be laid one over the other; they are
therefore made both in one piece whereby also a stiffer connection is effected and
one which prevents any side shifting in the wall. The arrangement according to
this second method offers also the advantage that the gas and water pipes may
be most conveniently placed between the two walls.
In by far the greater number of cases the two methods thus described would
suffice. Ate and however in Figure 1 and in Figures 2 and 3 other shapes of
projections are represented with suitable cross-pieces to fit them, which produce
an extremely rigid connection between the blocks and the walls.
The building blocks consist of a light beton (about one part cement to four
parts of sand) whilst the connecting pieces are composed of a closer material
either of a stronger beton or of burnt clay. In order to make it impossible
for the damp to pass from the outer to the inner wall the inner sides of the
blocks as well as the connecting pieces are smeared with tar or asphalte.
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 building block for cavity walls characterized by having dovo-tail aboned

page_text: projections on both sides by which an opening is left between it and the adjacent
block for the reception of a prismatic shaped connecting piece of suitably formed
section for connecting these blocks firmly together and serving also for binding
together the two parallel walls.
Dated this lat day of Noromban 1900
WM. P. THOMPSON & Co.,
Manchester, Liverpool, and London, Patent Agents.