Improvements in the Manufacture of Scoria or Slag Blocks, and Moulds therefor.
Year: 1895

page_text: Date of Application, 19th Aug., 1895-Accepted, 21st Sept., 1895
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Scoria or Slag Blocks, and
Moulds therefor.
I, CARL BRAND, of Southbank, Yorkshire, Slag Merchant, 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 :-
When manufacturing blocks of scoria or slag for paving or other purposes by
running liquid slag into moulds, cavities are formed in the blocks by shrinkage on
their solidifying, which cavities render them liable to fracture.
It was proposed in the Specification to Dobb's Patent No. 4408 of 1892 to do
away with this defect by casting the blocks with a head or cap, so that on cooling
and shrinking some of the material should pass from the head or cap into the body
of the block so as to fill out the cavities formed. Such heads or caps were formal
at one end of the block, and it has been found in practice that notwithstanding the
use thereof, cavities are still formed in the blocks, as the material of the cap only
partially fills them out, in addition to which the rough surface left at the end of
the block when the head is broken off prevents the necessary close fit of the blocks
when laid for paving.
According to my present improvements, I effectually do away with the formation
of cavities, and prevent the fractured surface from interfering with the laying of
the blocks, by so arranging the moulds that the blocks are cast in an inclined
position and that the head is formed on that surface of the block which subsequently
constitutes the under side thereof and is of a less width than the latter. By this
arrangement the material from the head can more effectually flow into the body of
the block to fill out any cavities on shrinking, and should any slight imperfections
still exist they will be situated at or near the underside thereof and consequently
will not be detrimental to the resistance of the block to wear and fracture, and
lastly, the rough surface left on knocking off the head, being ou the underside of
the block, does not interfere with the close fit thereof in paving and is moreover
confined to the central part of such surface.
I will describe my said improved mode of manufacture and the moulds therefor
with reference to the accompanying drawings, in which Fig. 1 shews a side view of
the mould in position for casting the block; Fig. 2 shews a front view of the same,
Figs. 3 to 8 shew detached details. The mould consists first of the two parts A A
forming the sides and front of the mould one of which parts is shewn detached in
back and side view at Figs. 3 and 4 and which are pivotted by lugs A' to lugs B¹
on the part B, which forms the back of the mould and which has an upward
projection B by means of which the mould is attached to the rim C of the wheel
round which the moulds are arranged in the known manner; Figs. 5 and 6 shew a
detached front and side view of the part B detached.
The bottom of the mould is formed by the plate E shewn in plan and side view
at Figs. 7 and 8 which is pivotted at E' to the part B, and has its tail end E'
weighted so as to tend to make it close upward. The parts A A are held together
in the closed position by a catch F, in which position they hold the bottom plate E
by means of claws A. The parts A A are so constructed as to form in addition
to the mould proper for the slag block, a mould A' for the before mentioned head
on the undersurface of the block, such head being of a less width than the block itself.
On the slag being run into the mould and allowed to harden, the catch F is raised
so as to allow the half moulds A A' to open on their hinges A' and thus set the

page_text: slag block with its head free, resting on the bottom plate E, which now turns down
on its hinge so as to deliver the block. This is now of the form shewn at Fig. 9,
where G forms the upper surface of the block while G' forms the under surface,
and has the head G' attached to it. When the block has completely solidified,
the head G2 is broken off, leaving the block as at Fig. 10, where the rough surface
at G¹ is at the underside, and consequently does not interfere with the accurate
fitting together of the blocks in paving.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. The improved manufacture of slag blocks wherein the head or cap is formed
on the underside of the block and of a less width than the latter, whereby the
formation of cavities in the block will be prevented and any imperfections will be
confined to the said underside, substantially as described.
2. Moulds for casting slag blocks with heads such as are referred to in the
preceding claim, consisting of the combination of the parts A. A' A' A' forming
the half moulds for the block and its head, and pivotted to the plate B B¹ B²
forming the back of the mould, to which is also pivotted the plate E E¹ E' forming
the bottom of the mould, substantially as described.
Dated this 19th day of August 1895.
ABEL & IMRAY,
Agents for the Applicant.