Improvements in or relating to Means for Joining Cement-blocks Pipes and the like."
Year: 1897

page_text: Date of Application, 21st Sept., 1897-Accepted, 18th Dec., 1897
""
COMPLETE SPECIFICATION.
Improvements in or relating to Means for Joining Cement-blocks
Pipes and the like."
STEN OLOF KJELLSTROM Engineer, of Stora Badstugatan 106, Stockholm, in
the Kingdom of Sweden, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement:
-
In joining cement blocks in general or pipes of cement as well as such blocks
as are perforated with longitudinal passages or conduits through which cables
are drawn, the blocks have generally been placed close together with no other tie
between them than a lip or flange of cement at the joints. It has also been
practised in the case of conduit blocks for telephone cables, in order to make the
said blocks self-sustaining, if loosened by renewed digging in the place where they
have been deposited, to insert iron bars in grooves hollowed out of the sides of
the blocks, said iron bars being secured by cement.
This invention relates to improved means of joining cement-blocks having the
form of pipes or ducts, to serve for instance as turbine races, water pipe sewers,
etc. where the weight of the mass conveyed makes it a matter of importance to
secure a reliable and strong joint. This result is obtained, in accordance with this
invention, by lodging the iron bars serving to unite the blocks, completely in the
interior of the body of the finished block, in order that the iron bars may not
become loosened when subjected to great load, or by lateral dislocation of the
blocks, being supported on all sides, when subject to bending by the material
composing the block, and for the purpose of allowing of the greatest possible
advantage being at the same time taken of the great adhesion to iron distinguishing
some mixtures of cement. The bars may either be embedded directly into the
blocks, or they may be inserted into special longitudinal holes arranged for them
in the blocks, the bars being secured in said holes by filling in around them with
cement. By this means the blocks may be quickly and securely joined to each
other.
In the accompanying drawing Figs. 1 and 2 show a conduit block of cement
in a sectional and lateral view. According to these figures each iron bar passes
through one block only, the iron bars being united at the ends of the blocks.
Figs. 3 and 4 show a locking arrangement for the bars inserted in the blocks;
said bars being viewed in an elevation and plan view. It should be mentioned,
however, that any other suitable locking arrangement may be employed. Figs, 5
and 6 respectively represent a cross-section and a longitudinal section of a modified
arrangement.
For joining the blocks there are either introduced bars a in the mass when the
blocks are being cast, or holes are made completely through the blocks for the
insertion of said bars, which are then secured by means of any suitable cement
mixture introduced into the hole. In each case the bars are so applied in the
blocks that there will be sufficient material around them to enable the bars to
support the blocks securely and prevent their dislocation laterally.

page_text: In the example of a locking arrangement shown in Figs. 3 and 4, the exterior
ends of the bars a are at the ends of the blocks, bent at an angle so as to form
a hook c, and, in uniting two blocks, a small iron strap or plate is placed over
the hooks c of two bars on bringing the latter together, and a wedge e is driven
in between the adjacent sides of the hooks. The exterior surfaces of the hooks lie
about flush with the end surfaces of the blocks, and for applying the locking
plates the surrounding material is cut out, or a suitable recess is made in
casting. By means of this locking arrangement a reliable joint is secured between
the blocks.
It has been found, however that several practical advantages, such as ease of
manufacture and a resulting increase in the speed of production etc., may be gained
if the joints between the iron when these are inserted in holes made for them in the
cement blocks and enter into or pass through two or more blocks, be partly or
altogether formed inside the blocks, the locking arrangement for the bars being
in this case if desired dispensed with the ends of the bars being only laid close
together, and the great adhesion of the cement poured into the hole to the iron
completing the joint. When inserting iron bars having their ends abutting in
the blocks, the ends of said bars may be bent or provided with bolt-heads, pro-
tuberances, etc., thus bringing into action the resistance of cement against
crushing.
This is illustrated in Figs, 5 and 6. The bars a are placed in close contact in
the holes provided for them in the blocks. The pouring into the holes of the
liquid cement-mortar for securing the bars may be done from the ends of the blocks
or through lateral openings provided in the latter. The ends of the iron bars
may be provided with protuberances. When it is desired to apply a lock to the
bar ends inside the blocks, apertures are made, when casting the blocks, opposite
the places where the bar joints are to be situated or holes are afterwards cut for
the deposition of the locking parts, the cement-mortar being poured into said
holes.
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:
In joining cement blocks, pipes or blocks used for underground cable conduits
or for similar purposes the arrangement of iron bars or rods embedded in the
blocks or inserted in longitudinal holes in the latter and then secured therein
by cement, said bars either being united to each other by means of a suitable
locking arrangement or being placed so as to abut with their ends, substantially
as described.
Dated this 91at dav
1007
BOULT & WADE
Agents for the Applicant.