Improvements in Apparatus for the Manufacture of Bricks, Clay Blocks, Tiles, and the like.
Year: 1898

page_text: Date of Application, 24th June, 1898-Accepted, 30th July, 1898
Improvements in Apparatus for the Manufacture of Bricks, Clay
Blocks, Tiles, and the like.
I, RICHARD BRADSHAW, of 41, Wavertree Vale, Liverpool, in the County of Lan-
caster, Brick Manufacturer, 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;-
This invention relates to the manufacture of bricks, clay blocks, tiles and the
like, and has for its object certain improvements which will now be described,
reference being had to the accompanying drawings, in which,
Figure 1 is a sectional elevation of brick making machinery arranged according
to my invention,
Figure 2 a plan.
Referring to these figures A is a pug mill shaft of suitable length mounted in
thrust bearings B at or near the centre thereof, and at each side of the thrust bear-
ings I arrange a pug cylinder C and I), in which the clay is worked or kneaded to
blend its materials and to render it plastic for bricks etc. These cylinders may be
horizontal or otherwise and they are arranged in alignment. The shaft is armed
at opposite ends with rotary blades to work the clay in the two cylinders and these
blades having a spiral or oblique position their tendency is to force the clay con-
stantly to the exits E. These exits constitute dies through which the clay passes
from the cylinders in a stream F, G being adjustable revolving moulds which
govern the width of the die, and which can be shaped to give any desired con-
figuration to the edges of the stream of clay. One of the cylinders C is larger in
diameter than the other ]), The larger one (which is used for plastic clay I
call the low pressure cylinder and the smaller one 1) which is by preference used
for less plastic or dry clay I call the high pressure cylinder. By this arrange-
ment therefore it will be seen that the forces exerted in opposite directions on the
pug shaft A in comminuting the clay, counterbalance each other because although
there is a smaller body of clay in the cylinder 1), than there is in the cylinder C,
owing to the different diameters of the cylinders, yet the clay in the cylinder D
is less plastic than the clay in the cylinder C, and therefore the resistance to the
blades is equal, the respective diameters of the two cylinders being proportioned
to secure this result. Hence the forces on each end of the shaft mutually re-act
against each other, and the thrust journals of the shaft are in equilibrium, no
terminal bearings at ends of shafts being required. In proximity to the thrust
bearings between the two cylinders I arrange a suitable spur wheel H rotating
the shaft. This wheel is driven by the pinion I on the counter-shaft J which is
furnished with fast and loose pullies K. C and D are hoppers for feeding the
clay into the cylinders. In order to insure the most perfect mixing and tempering
of the clay I arrange in the interior of each of the cylinders C
and D near each end thereof, a perforated dise L placed transversely
to the stream of clay through which perforations the comminuted clay
is forced. This disc subdivides the clay into streams, which are again

page_text: amalgamated together after passing through the perforations by the bell
mouthed shape M of the inside of the cylinder covers, the clay being thus
thoroughly pugged in the cylinders and then separated and again amalgamated
before being delivered through the dies. This arrangement prevents any possi-
bility of the stream of clay delivered through the die becoming laminated or
cored and insures that the bricks when made cannot be otherwise than good. The
perforated disc may be stationary, or it may be made to revolve if preferred.
Furthermore if the rollers G be employed, the bricks are produced with good sharp
edges as the clay has no friction, being drawn through instead of forcing itself
through, and is delivered in one unbroken stream. Owing to the stiffness of the
clay used in the high pressure cylinders, less water has to be evaporated in the
drying than in the clay pugged in the low pressure cylinder, thus saving con-
siderable time and avoiding the risk of loss by bad weather. The stream of clay
after having been delivered through the dies may be cut by means of wire cutters
or in any other suitable manner after which the cut bricks are delivered on to
barrows or travelling bands.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
1. In pug mills for the manufacture of bricks, clay blocks, tiles and the like,
in which the clay is worked or kneaded by blades in pug cylinders on revolving
shafts so that on its escaping it is a homogeneous mass without any hard lumps,
the use or employment in each mill of two cylinders arranged in alignment, one of
which is of smaller diameter than the other and of a shaft mounted between the
cylinders in thrust bearings, one end of this shaft having blades which work the
clay in the larger cylinder and the other end of the shaft having blades which
work the clay in the smaller cylinder, whereby if plastic clay be worked in the
larger cylinder and dry or stiff clay in the smaller, the forces exerted in opposite
directions in comminuting the clay, counterbalance each other substantially as
described.
2. In machinery for making bricks, tiles and the like in which two pug mills
are disposed one at either side of the motive power, forming the cylinder of one
of the pug mills of a smaller diameter than the other, and so proportioning the
diameter of each that if plastic clay be used in the larger cylinder and stiffer clay
in the other cylinder, the strain or force exerted on the shaft of the smaller cylinder
in comminuting the stiffer clay will be counterbalanced by that exerted on the
shaft of the larger cylinder in comminuting the plastic clay, substantially as
described.
3. The use in machinery for making bricks, tiles, clay blocks and the like of
perforated discs located transversely to the stream of clay and so arranged as to
subdivide the stream of clay, in combination with means for again amalgamating
the clay before delivery through the dies, substantially as and for the purpose
described.
WM. P. THOMPSON & Co.,
Of 6, Lord Street, Liverpool, Patent Agents for the Applicant.