Improvements in the Manufacture of Blocks of Terra-cotta and like Materials, and in Machinery for this Purpose.
Year: 1889

page_text: Date of Application, 26th Mar., 1889
Complete Specification Left, 27th Dec., 1889-Accepted, 8th Feb., 1890
PROVISIONAL SPECIFICATION.
Improvements in the Manufacture of Blocks of Terra-cotta and like
Materials, and in Machinery for this Purpose.
We, HENRY LEWIS DOULTON, Potter, and STEPHEN HENRY LEEOR, Manager, both
of the Albert Embankment, Lambeth, in the County of Surrey, do hereby declare
the nature of this invention to be as follows:-
1
It is necessary to make large blocks of terra cotta hollow otherwise owing to their
size it would be difficult or impossible to dry them. Heretofore they have been made
by lining moulds with sheets of clay, by building up the form by hand, running with
templates or reverses or expressing as a continuous stream of a given section from a
die forming only the outer surface with but few internal webs or supports. Such
blocks are usually mere shells not strong enough to be used for building purposes
without filling.
According to our invention we make blocks with a number of small cells or cavities
somewhat similar to the holes in the well known perforated bricks except that in place
of running completely through the block they are only open at one face stopping
short of the opposite face. Such blocks may be moulded at the closed end and owing
to the smallness of the cells can be employed for building purposes without any
filling and yet since the cells in them are open at one end the clay can dry
thoroughly.
The machinery and methods we use for making such blocks are somewhat similar
to those employed in producing socketted drain pipes but differ in important respects.
The stream of clay when it first issues from the die at the mouth of the press enters
a box temporarily attached at the mouth of the die. This box is a mould made to the
shape of the surface or surfaces towards the end of the block other surfaces being
formed by the die. When the box is filled it is liberated and then moves away in
the usual way, being supported on a table, the stream of clay following it. When
the block has attained a sufficient length the clay is cut off near the die and the box
replaced for another block. In order to make the hollows in the clay we provide pins
which are carried at the mouth of the die and enter the box reaching almost but not
quite to its moulded surface. We make these pins hollow and provide openings at
their ends so as to allow the air to escape from the box and to supply air to fill the
cells as they are formed.
For blocks of certain shapes and sizes we make the cells by means of a screw or
other press forcing a number of pins into a box containing reverse blocks as before
described. We, in this case also, make these pins hollow with openings at their
ends.
H. L. DOULTON.
S. H. LEECH.
COMPLETE SPECIFICATION.
Improvements in the Manufacture of Blocks of Terra-cotta and like
Materials, and in Machinery for this Purpose.
We, HENRY LEWIS DOULTON, Potter, and STEPHEN HENRY LEECH, Manager, both
of the Albert Embankment Lambeth, in the County of Surrey, 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 :-
It is necessary to make large blocks of terra-cotta hollow otherwise owing to their
size it would be difficult or impossible to dry them. Heretofore they have been made
ID 017

page_text: by lining moulds with sheets of clay, by building up the form by hand, running with
templates or reverses or expressing as a continuous stream of a given section from a
die forming only the outer surface with but few internal webs or supports. Such
blocks are usually mere shells not strong enough to be used for building purposes
without filling.
According to our Invention we make blocks with a number of small cells or cavities
of circular, hexagonal or other form somewhat similar to the holes in the well known
perforated bricks except that in place of running completely through the block they
are only open at one face stopping short of the opposite face. Such blocks may bo
moulded at the closed end and owing to the smallness of the cells can be employed
for building purposes without any filling and yet since the cells in them are open at
one end the clay can dry thoroughly.
There is also the further advantage that such blocks can be cut at the back or ends
to suit any required notching for iron work or the like without interfering with their
proportionate strength, whereas the ordinary terra-cotta blocks are seriously damaged
and weakened by being cut down after being made.
Such blocks can be made in a variety of ways.
In some cases we first express from a die a stream of clay with longitudinal
perforations in it just as is done when making the well known perforated bricks except
that it is generally convenient to have the stream of larger section and to cut it
longitudinally or transversely into pieces of the desired size.
Suitable lengths or pieces having been cut off one end is smoothed by hand with a
tool or template in such manner as to close one end of each of the perforations.
Figure 1 is a longitudinal section of a block so produced. In place of the end being
flat it may be moulded as shown in Figure 2. The sides also as well as the ends may
be moulded by working with templates or the die may be so formed as to produce
the moulded sides, the end being moulded by hand as above described. Or the shell
of the block may be produced by lining a mould with sheets of clay such shell being
afterwards filled with a piece or pieces of the perforated clay. Figures 3 and 4 are
longitudinal sections respectively of the two parts and of the completed block. All the
blocks after being formed as above described are dried and fired in the usual way.
We also make such blocks by machinery and methods which are somewhat similar
to those employed in producing socketted drain pipes but which differ in important
respects.
The stream of clay when it first issues from the die at the mouth of the press
enters a box temporarily attached at the mouth of the die. This box is a mould made
to the shape of the surface or surfaces towards the end of the block other surfaces
being formed by the dic. When the box is filled it is liberated and then moves away
in the usual way, being supported on a table, the stream of clay following it.
When
the block has attained a sufficent length the clay is cut off near the die and the box
replaced for another block. In order to make the hollows in the clay we provide
pins which are carried at the mouth of the die and enter the box reaching almost but
not quite to its moulded surface. We make these pins hollow and provide openings,
at their ends so as to allow the air to enter and fill the cells as they are formed.
Or in place of the whole box being moveable we have the bottom only moveable.
Figure 5 is a vertical section of an apparatus constructed in this manner.
A is a cylinder containing the clay which is forced downwards by the usual
plunger. B is a plate, perforated with a number of holes which carries short tubes C
through' which the clay passes. D is a second plate which supports the stems E of
the pins, there being a space between the plates B and D so that the air which enters
at the air holes F passes down through the hollow stems to the pins and fills the cells
as they are formed. The reverse blocks G are placed upon a rising and falling
table H in the box below the plate D. The table H and the sides of the box are
perforated with holes J to allow air and a small amount of clay to. escape so as to
ensure sound mouldings. The table H. is pivotted at K so that when below the; box
it can be turned down to remove the block. .
Figure 6 shows the details of construction of the pins we prefer to employ. Li is a

page_text: hollow screw stem which is secured to the plate B by the lock nut M. N is an outer
tube screwing on to the stem L so that the length of the pin can be varied. The
ends of the pin are of wood so that they can be readily cut to vary their length and
form. These ends also are perforated as shown, the bottom of the hole through them
being preferably furnished with a loose flap valve P to prevent the entrance of clay.
The lower part of Figure 5 shows the bottom of a press in which the follower is
made to rise slightly after the mould box is full or nearly full of clay and thus further
secure sound mouldings. In this arrangement the stem carrying the table is made
in two parts screwing together a lever R being provided by which the lower part of
the stem can be turned so pressing the table upwards. The stem Q is secured in
position by means of a cotter S actuated by a lever T.
For blocks of certain shapes and sizes we make the cells by means of a screw or
other press forcing a number of pins into a box containing reverse blocks as before
described. We, in this case also make these pins hollow with openings at their ends.
Figure 7 shows a press constructed in this way. In this case the cylinder A,
plunger B and plate Care dispensed with, the plate D carrying the pins being forced
downwards by the screw and hand wheel S. In this case the sides of the mould box
are hinged at T to allow of the blocks being withdrawn.
Having now particularly described and ascertained the nature of our said Inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
-
1. Blocks of terra cotta and like materials substantially as described, having in them
a number of small cells or cavities of any desired form, open at one face of the block,
but stopping short of the opposite face.
2. Blocks of terra cotta and like materials substantially as described with one or
more moulded faces and having in them a number of small cells or cavities open at
one face, but stopping short of the opposite moulded face.
3. The process of making blocks such as are referred to in claims 1 and 2, consisting
in forcing clay past a number of pins, bulbs or the like into a mould, substantially as
described.
4. The process of making blocks such as are referred to in claims 1 and 2,
consisting of forcing pins bulbs or the like into a mould filled with clay substantially
as described.
5. In apparatus for making blocks such as are referred to in claims 1 and 2, the
employment of hollow pins to allow of the supply of air to the cells as forined,
substantially as described.
6. Machinery for manufacturing blocks of terra cotta and like materials substantially
as described and shewn in the drawings.
TL: aul
auhan 1000
CARPMAEL & Co.,
Agents.