IMPROVEMENTS IN MACHINERY FOR THE MANUFACTURE OF BRICKS FROM PLASTIC CLAY
Year: 1872

page_text: . LETTERS PATENT to Robert Spence and Edmund John Spence,
trading under the Name of Murch & Spence, of Bridgwater,
Somerset, Ironfounders and Engineers, for the Invention of "IM-
Sealed the 13th September 1872, and dated the 20th March 1872.
PROVISIONAL SPECIFICATION left by the said Robert Spence and
Edmund John Spence at the Office of the Commissioners of
Patents, with their Petition, on the 20th March 1872..
We, ROBERT SPENCE and EDMUND JOHN SPENCE, trading under
the Name of Murch & Spence, of Bridgwater, Somerset, Ironfounders
& Engineers, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN MACHINERY FOR THE MANUFACTURE OF BRICKS FROM PLASTIC
CLAY," to be as follows:-

page_text: from plastic clay, and consists principally of a vertical rotating plate
with apertures at or near the periphery into which the plastic material
can be forced by pressure or pug blades arranged in proximity to the
plate, the plate being caused to rotate continuously or intermittently
as desired, and caused to dip or pass into a bath of water to facilitate
the entry and exit of the clay to and from the dies or apertures,
the expulsion of the body being effected by plungers or other con-
trivances.
One method of carrying our Invention into effect is hereafter
described: A moulding table or disc of circular form is mounted
upon a horizontal shaft or axle, and receives an intermittent motion
in one direction through a paul and ratchet teeth from a prime mover.
The disc has chambers or die spaces formed through it near its periphery,
which are filled in succession with the plastic body by the blades or
scrapers of pug mills one arranged on each side of the disc, so that the
two supplies of clay meet and are compressed into one body; the disc
then rotates or moves on a step and the next space becomes filled, the
former body of clay having been severed by the edges of the mills
which touch the disc for the purpose. The filled spaces travel on until
they come opposite a plunger to which a transverse movement is given
to push the body of compressed clay out of the space on to a board
or on to an endless belt from which it can be removed to be dried
or otherwise treated. The lower part of the disc passes through a
trough of water which lubricates the moulds, and permits of the clay
entering and leaving without the surfaces or edges being torn or made

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Robert Spence and Edmund John Spence in the
Great Seal Patent Office on the 20th September 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ROBERT
SPENCE and EDMUND JOHN Spence, trading under the Name of Murch
and Spence, of Bridgwater, Somerset, Ironfounders and Engineers, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twentieth day of March, in the year
of our Lord One thousand eight hundred and seventy-two, in the
thirty-fifth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto us, the said Robert Spence and Edmund
John Spence, Her special licence that we, the said Robert Spence
and Edmund John Spence, our executors, administrators, and assigns,
or such others as we, the said Robert Spence and Edmund John
Spence, our executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make,
use, exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN MACHINERY FOR THE MANUFACTURE OF BRICKS FROM PLASTIC
CLAY," upon the condition (amongst others) that we, the said Robert
Spence and Edmund John Spence, or one of us, our executors or
administrators, by an instrument in writing under our, or one of our, or
their, or one of their hands and seals, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that we, the said Robert Spence and Edmund
John Spence, do hereby declare the nature of the said Invention, and
in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement thereof,
reference being had to the Drawings hereunto annexed, that is to
say:
This Invention relates to machinery for the manufacture of bricks.

page_text: from plastic clay, and consists principally of a vertical rotating plate
with apertures at or near the periphery into which the plastic material
can be forced by pressers or pug blades arranged in proximity to the
plate, the plate being caused to rotate intermittently and to dip or pass
into a bath of water to facilitate the entry and exit of the clay to and
from the dies or apertures, the expulsion of the body being effected by
plungers.
The method we propose of carrying our Invention into effect is here-
after detailed in combination with the annexed Drawings, in which
Figure 1 shows an end view, and Figure 2 a plan. A moulding table
or disc a of circular form is mounted upon a horizontal shaft or axle b,
and receives an intermittent motion in one direction through a paul,
ratchet teeth, and levers, as indicated by dotted lines in Figure 1, from
a belt of a prime mover, also shewn in dotted lines. The disc has
chambers or die spaces c, c, formed through it near its periphery, which
are filled in succession from both sides with the plastic body by the
blades or scrapers of a double-acting pug mill e, one mill or pug being
arranged on each side of the disc a, so that the two supplies of clay meet
and are compressed into one body; the disc a then rotates or moves on
a step under the action of the paul and the next space becomes filled,
the former body of clay having been severed by the edges f, ƒ, of the
mill casing which touch the disc for the purpose. The filled spaces
travel on intermittently until they arrive opposite a plunger g to which
a transverse movement is given by gearing h, to push the body of
compressed clay out of the space on to a pallet board, or on to an
endless belt from which it can be removed to be dried or otherwise
treated. The lower part of the disc passes through a trough d of
water which lubricates the moulds, and permits of the clay entering
and leaving without the surfaces or edges being torn or made ragged.
One or more of the mould faces may be perforated for vent purposes,
the perforations being kept clean by pins or prickers actuated auto-
matically.
The blades of the mills, which are arranged one to the right and one
to the left for feeding purposes, may have passages through them to
allow the clay to pass should the mill be feeding the clay at too fast
a rate, or should it be reversed from any cause.
It will be observed by examining the Drawings that there are three

page_text: dies apertures c within the interior of the barrel i of the mill, the lower
rising one becoming filled under the pressure of the feeding blades,
while the disc remains stationary and becomes gradually and com-
pletely filled before and at its next movement in approaching the
central part of the mill where the pressure is the greatest; the disc
then moves another step under the action of the paul, and the clay in
the filled die receives a further compression, the two last being sufficient
to expel any air that may have remained in the clay after the first
compression, so that the shaped body of clay is, so to speak, perfect, the
superfluous clay being struck off in passing through between the side.
walls ff, of the casing. That filled die then moves on until it comes
opposite the plunger g, which is timed for entering the die at the proper
time without fear of the edges of the clay being made ragged, and
pushes it outwards on to a pallet board or on to an endless belt, to be
then carried to the hacks or to the drying sheds to be deprived of
the moisture previous to firing in the kiln or stack.
In order to relieve the plunger as freely as possible from the moist
clay, we propose in some cases to make the plunger stem hollow, and
cause it to work into a vacuum chamber where the vacuum is main-
tained by means of an air pump. The face of the plunger can be
covered with leather or other material to come into contact with the
clay, and the vacuum can be broken by a slot hole in the stem exposing
itself and allowing atmospheric air to rush in.
The knives or feeding blades of the pugs can be arranged close
together on the axles, and screens can be fitted in the casing for the
clay to pass through before it enters the dies in the disc.
The arrangement of the vertical disc and horizontal pug mill or mills,
as before described, is the best method of accomplishing the object we
have in view, but we do not limit ourselves to fitting or arranging the
parts in that position, as by slight modifications they may be arranged
differently, so that the die disc can work horizontally and the pug or.
pugs vertically.
And having now described the nature of our said Invention, and in
what manner the same is to be performed, we declare that we claim,--
Firstly. The improvements herein-before set forth and shewn, by
which clay or its compounds can be fed automatically into moulds or
.

page_text: TWO.
ROBT. SPENCE.
(L.S.)
EDMUND JOHN SPENCE. (L.S.)