IMPROVEMENTS IN APPARATUS FOR MAKING A RATED BREAD
Year: 1864

page_text: LETTERS PATENT to Robert Luke Howard, of No. 85, Upper White Cross
Street, in the County of Middlesex, Engineer, and John Dauglish, of
Reading, in the County of Berks, M.D., for the Invention of "IMPROVE-
PROVISIONAL SPECIFICATION left by the said Robert Luke Howard
and John Dauglish at the Office of the Commissioners of Patents, with
their Petition, on the 22nd December 1864.
We, ROBERT LUKE HOWARD, of No. 85, Upper White Cross Street, in
the County of Middlesex, Engine and JOHN DAUGLISH, of Reading, in the
County of Berks, M.D., do herel declare the nature of the said Inven-
tion for "IMPROVEMENTS IN APPARATUS FOR MAKING A RATED BREAD," to be as
follows:-
These improvements relate to 1st, the mode of discharging the dough;
2nd, to the apparatus for condensing and exhausting gas and air; 3rd, to the
apparatus for mixing and making the dough. Hitherto in the manufacture
of aërated bread it has been customary to discharge the dough or paste
from the mixing vessel in which it has heen prepared through certain
regulated openings in such a manner that it may be divided into separate
pieces or quantities, each suitable to form one loaf, as it issues by the
force of the pressure from within the mixer. By such a method, it will
be seen that the mixing apparatus has to remain idle whilst the operation
of making the dough into loaves is being performed, and vice versa, the
apparatus for discharging the dough has to remain idle whilst the mixing

page_text: or preparing the dough is being performed.
performed. Now we propose to avoid as
much as possible the delay caused by such a mode of operating, by placing
between the mixing vessel and the apparatus through which the dough is to be
discharged for division into loaves a vessel or chamber, into which the dough
may be discharged in bulk, in which vessel or chamber is to be retained a
sufficient pressure of gas to prevent any injurious expansion or vesiculation
of the dough, and to effect its discharge therefrom through the regulating
apparatus for making into loaves, which is to be affixed thereto instead of to
the mixing vessel as heretofore.
The improvements in the apparatus for condensing the gas and air and for
exhausting air and gas from the mixer, consist in driving the pumps direct
from the engine shaft by means of cranks, excentrics, or cams, without the
intervention of straps, pulleys, or other wheels; likewise, when desirable, in
constructing the frames of the mixer or other parts of the apparatus hollow, in
such a manner as that they may be used as receivers for condensed air and gas.
The improvement in the apparatus concerned in mixing the dough consists
in making the water vessel (which has hitherto been constructed of copper) of
the same material as the mixing vessel, viz., of iron, and of one continuous
piece of metal with the upper portion of the mixing vessel, and in order to
prevent chemical action in and destruction of the metal, painting or coating it
with a composition of rosin and bee's-wax, or rosin and tallow. This water
vessel, instead of being supplied with glass water gauges for measuring the
water, will be connected with a separate vessel for the purpose of measuring the
necessary charge of water before it is admitted into the vessel connected to the
mixer. The form of the mixing arms for mixing and kneading the materials
within the mixer will be varied from those ordinarily used; the arms or blades
instead of being placed for the most part at right angles with the horizontal
axis of the mixer will be parts or nearly parts of a circle, and will be placed
concentric or nearly so with the centre of the mixer.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Luke Howard and John Dauglish in the Great
Seal Patent Office on the 20th June 1865.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, ROBERT
LUKE HOWARD, of No. 85, Upper White Cross Street, in the County of
Middlesex, Engineer, and JOHN DAUGLISH, of Reading, in the County of
Berks, M.D., send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of December, in the year of our
Lord One thousand eight hundred and sixty-four, in the twenty-eighth year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto us, the said Robert Luke Howard and John Dauglish, Her special
licence that we, the said Robert Luke Howard and John Dauglish, our
executors, administrators, and assigns, or such others as we, the said Robert
Luke Howard and John Dauglish, 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 APPARATUS FOR MAKING AERATED BREAD," upon the con-
dition (amongst others) that we, the said Robert Luke Howard and John
Dauglish, our executors or administrators, by an instrument in writing under
our or their hands and seals, or under the land and seal of one of us or them,
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 Luke Howard and John
Dauglish, do hereby declare the nature of the said Invention, and in what
manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement thereof, that is to say :-
These improvements relate to, first, the mode of discharging the dough;
second, to the apparatus for mixing and making the dough; third, to the
apparatus for condensing and exhausting gas and air. Hitherto in the
manufacture of aerated bread it has been customary to discharge the dough
in paste from the mixing vessel in which it has been prepared through
certain regulated openings in such a manner that it may be divided into
separate pieces or quantities, each suitable to form one loaf, as it issues by
the force of the pressure from the mixer. By such a method it will be
seen that the mixing apparatus has to remain idle whilst the operation of
making the dough into loaves is being performed, and vice versa, the apparatus
for discharging the dough has to remain idle whilst the mixing or preparing
the dough is being performed. Now we propose to avoid as much as possible
the delay caused by such a mo:le of operating by placing between the mixing
vessel and the apparatus through which the dough is to be discharged, for
division into loaves, a vessel or chamber into which the dough may be dis-

page_text: charged in bulk, in which vessel or chamber is to be retained a sufficient
pressure of gas to prevent any injurious expansion or vesiculation of the
dough, and to effect its discharge therefrom, through the regulating apparatus
for making into loaves, which is to be affixed thereto instead of to the mixing
vessel as heretoforc.
The improvements in the apparatus for condensing the gas and air for
exhausting air and gas from the mixer consist in driving the pumps direct
from the engine shaft by means of cranks, excentrics, or cams, without the
intervention of straps, pullies, or other wheels; likewise, when desirable, in
constructing the frames of the mixer or other parts of the apparatus hollow, in
such a manner as that they may be used as receivers for condensed air and gas.
The improvement in the apparatus concerned in mixing the dough consists
in making the water vessel (which has hitherto been constructed of copper)
of the same material as the mixing vessel, viz, of iron, and of one continuous
piece of metal with the upper portion of the mixing vessel, and in order to.
prevent chemical action and destruction of the metal, painting or coating it
with a composition of rosin and bee's-wax or rosin and tallow. This water
vessel, instead of being supplied with glass water guages for measuring the
water will be connected with a separate vessel for the purpose of measuring
the necessary charge of water before it is admitted into the vessel connected
to the mixer. The form of the mixing arms for mixing and kneading the
materials within the mixer will be varied from those ordinarily used; the arms
or blades instead of being placed for the most part at right angles with the
horizontal axis of the mixer will be parts or nearly parts of a circle, and will
be placed concentric or nearly so with the centre of the mixer.
Having thus stated the nature of our said Invention we will proceed more
fully to describe the manner of performing the same.
DESCRIPTION OF THE DRAWINGS.
Figure 1, Sheet I., is a front elevation of a mixing apparatus, with the
intermediate chamber for receiving the dough from the mixer; Figure 2
shews a transverse section of the same taken at the line Z, Z, in Figure 1.
A is the water vessel; B, the mixing vessel; and C, the intermediate
vessel which we call the "receiver." These three vessels are connected to
each other, and are supported in their position by two hollow columns D, D,
which are of large diameter in proportion to their height, which will when
attached to a firm foundation make a sufficient frame for the working of the
machine, whilst such columns form air-tight receivers, into which gas is con-
densed by the pumps hereafter to be described. By observing the continuous

page_text: action of the metal forming the water vessel A, and the mixing vessel B, it
will be seen in what manner we construct these two vessels of one continuous
piece. And when the metal used is iron, or otherwise such as is liable to be
injuriously acted upon chemically, we paint the inside of the water vessel and
such parts as are liable to be affected with a hot composition consisting of
equal parts by weight of rosin and bee's-wax melted and mixed together. The
metal previous to the application of the composition is to be beated. The top
of the water vessel is cast open. In the plate or diaphragm which separates
the water vessel from the mixer there is an opening left in the casting, into
which is fitted a metal piece a, which metal piece carries a valve b, and an
equilibrium pipe c.
The valve 6 is attached to a rod passing upwards through
a stuffing box in the cover of the water vessel, by which rod the valve can be
closed and opened. The equilibrium pipe passes through the metal piece to the
under side of the cover of the water vessel; the object of this pipe is to effect
a communication between the upper part of the water vessel and the upper
part of the mixing vessel for the free passage of gas. The equilibrium pipe
instead of being placed inside the water vessel may be outside, with its two
extremities attached to and communicating with the upper part of the water
vessel and the mixing vessel respectively. The equilibrium pipe may be fitted
with a stop-cock for shutting off the communication between the two vessels
when necessary for the purpose of charging the water vessel with water and
aerating and preparing it for a succeeding mixing whilst the previous charge
is being mixed and kneaded into dough. The water vessel is furnished with
a lid or cover d, d, to which the stuffing box already referred to is attached,
and also the several cocks or valves for admitting water and gas. This cover
is shewn in plan at Figure 3, the positions of the stuffing box and of the
screw cocks or valves are indicated. The centré cock k is attached to a pipe
which passes downwards into the water vessel nearly to its bottom, and attached
to it is a rose or distributor for the purpose of dividing the gas (which
is passed through it from the receiver of condensed gas) into minute
streams so as to secure the due aeration of the water.
placed near the circumference of the cover, communicates with the water
measure Efr the admission of water to the water vessel where the
proper quantity of water for a mixing as been previously measured.
Two cocks m and n are applied to the cover; the cock m communicates with
the vacuum pump for discharging the gas, and the cock n communicates with
the vacuum pump for withdrawing the air from the mixing apparatus; or
sometimes the equilibrium pipe is placed outside, as shewn in Figures 4 and 5,
where the three cocks m, n, and o are attached together to the side of the
The second cock l,

page_text: water vessel, the cock m communicating with the vacuum pump for dis-
charging the gas from the mixing apparatus into the gas holder, the cock n
communicating with the vacuum pump for withdrawing the air from the
mixing apparatus. These two cocks connect (with the stop-cock o) the upper
mouth of the equilibrium pipe placed outside the water vessel, so that the
communication through the stop-cocks m and n and the equilibrium pipe c is
only through the stop-cock o. A fourth stop-cock p is shewn at the lower end
of the equilibrium pipe, where it communicates with the mixing vessel. The
equilibrium pipe when outside, as in Figure 5, is between the cocks o and p,
and formed of glass to enable the workman to detect the passage of flour with
the gas and air, which flour if allowed to enter far into the pipes and get into
the pump valves would cause much trouble. Screw plugs are provided for
clearing out any flour that may be deposited in the glass tube. The cover and
opening of the mixers shewn at F are for the admission of flour into the mixer,
and are of the same description as is ordinarily used for this purpose. The
lower parts of the receiver C slightly taper to the mouth G, to which is to be
attached measuring and discharging apparatus, preferring such as are described
in Dr. Danglish's Patent of 16th March 1864, No. 677. The receiver C is
attached to the bottom of the mixer B, but slightly towards one side, by means
of flanches. There is an opening or communication between the two vessels
at H; this opening is capable of being closed by means of a door or slide I.
This slide has its face formed of a circular plate, with the outside edge or
circumference made sharp in its centre. At the back of this plate F is a
screw having a fine thread, represented at e. Between this stud and the edge
of the plate at the back are attached teeth in the form of a bevilled wheel,
into which fits a bevilled pinion at f. Across the back of this plate or slide a
strong metal bar passes, having its two ends fitted into slots, to allow of its
being drawn backwards and forwards across the opening between the two
vessels by the rod g, actuated by the rack and pinion h, and in the centre of
this bar is a hole with a female screw, into which the stud or screw e works.
By this arrangement it will be seen that the slide I may be drawn backwards,
and forwards, so as to close or open the communication between the two
vessels B and C by the rack and pinion h,.and as the rack at h, instead of being
formed with ordinary teeth is formed of concentric collars, which serve as
teeth, the rod g is capable of being turned on its centre, and thus to give
motion to the bevilled pinion f, which by acting on the teeth at the back of
the slide I, will, by screwing the slide nearer to or farther from the face of
the opening, slacken or loosen the joint, and thus facilitate the working of the
slide backward and forward.

page_text: The mode of using the receiver is as follows:-The dough having been
mixed in the mixer B, the mixing arms are made to rest so as to allow of the
dough settling down at the bottom of the mixer over the opening H. The
receiver C is to be filled with gas of an equal density to that used and retained
in the mixing vessel B, between the upper parts of which two vessels B and C
there is to be a communication by means of an equilibrium pipe fitted with a
stop-cock i, i. The dough having settled down over the slide I, the commu-
nication by the equilibrium pipe is then to be opened, after which the opening
at E is opened by sliding back the plate I, when the dough will descend into
the receiver C, displacing the gas which flows into the mixer. The discharge
of the dough from the mixer into the receiver may be facilitated by the mixing
arms being allowed slowly to revolve. When the discharge has taken place,
the opening I may be closed, and likewise the equilibrium pipe, and a fresh
mixing of dough may be proceeded with whilst the dough in the receiver C is
being measured off.
In the centre of
These blades
inch thick, set
Figure 6 shews our improved form of mixing arms to be fitted on the mixing
shaft revolving within the mixer B. It consists in substituting for the blades
hitherto used blades having a circular form, being parts or segments of circles
more or less concentric with the centre of the mixer. At Figures 2 and 6
the form and position in which we prefer to arrange these arms are given.
Figure 6 is a side elevation of the arms, and in Figure 2 an end elevation of
the same is shown. By preference each set of mixing arms consists of 6 blades,
each blade being equal to a little more than a half circle.
each blade is a strong boss, by which it is fixed on the shaft.
may be made of bar iron, about two inches wide and half an
edgeways immediately next the boss, but gradually twisted, so as to be at an
angle of about 45 degrees at the extreme ends to where they are fixed to
their boss. The front or forward edge of these blades is made chisel-shaped,
whilst the back edge is left blunt. Three of these blades are set in one plane,
and the other three blades are set in a plane at right angles with the first-
mentioned plane. The free ends of these blades as they approach the centro
of the mixer are preferred to be made slightly to "drop behind," as repre-
sented at c, Figure 6, so as to give the dough whilst being mixed a tendency
to move towards the centre rather than to be pressed against the sides of the
mixer. We do not confine ourselves to any particular size, number, or posi-
tion of these blades.
We will now proceed to describe more fully the manner of carrying out
another part of our Invention by reference to Sheet 2 of the Drawings.

page_text: Figure 1 shews a side elevation of square cast-iron frame X, X, X, X,
having the cylinders or barrels of four pumps (two exhausting and two con-
densing pumps) bolted in a line side by side on the top of the frame or base,
and in the same line with the steam cylinder of the engine which actuates the
pumps. Figure 2 shews an end elevation of this frame with other parts.
Immediately under the centre line of these pumps is placed the first motion
shaft, driven by the steam engine and forming the crank and fly-wheel shaft of
the engine to which the crank E and fly wheel F are fitted. On to this shaft
are fitted or keyed (besides the excentrics connected with the steam engine)
four excentrics, one immediately under each pump barrel, and to these ex-
centrics are fitted the necessary connecting rods for giving reciprocating motion
to the solid rams, which work through cup leathers fitted round the mouth of
the pump
barrels (as shewn at Z, Z, Figure 5); these rams are driven right
home up to the valve plates at the upper extremity of the barrels. The plate
to which the pump barrels are fitted at the top of the frame forms the bottom
of a water cistern W, W, through which 'cold water is made to circulate for
the purpose of keeping the pumps cool. The mode of fitting the pump barrels
to this plate is shewn in section at Figure 5; each barrel is raised on a stool
Y, Y, a short space above the bottom of the cistern or plate. This stool
being open at the sides allows the water to circulate freely, and under the
mouth of the barrel there is an opening in the stool, also in the plate or
bottom of the cistern, for the passage of the pump ram into the mouth of the
barrel. In order to prevent the water leaking through the opening in the
cistern by which the ram passes, each opening is furnished with a cup leather
shewn at U. By thus fitting the pumps so as to insure the mouths of the
barrels being kept under water, also near to the bottom of the cistern, and yet
raised above the bottom, the joint formed round each of the rams by the cup
leathers, where it works into the mouth of the cylinder, is kept constantly
sealed by water against the possible leakage of air, whilst at the same time
the cup leathers are kept moist and in working condition.
By these arrangements we are enabled greatly to reduce the size of the
condenser pumps, and in order to accomplish the condensation in the most
effective manner, the condensing pumps are made to deliver the air and gas
into the two receptacles forming the pillars supporting the mixing apparatus,
and from these receptacles the gas is expanded as required into the aerating,
inixing, and discharging apparatus. Now, although as a general rule the
condensing pumps may be kept at work constantly throwing gas and air, yet
in order to provide the means of stopping or regulating the work performed.

page_text: by all the pumps whilst the rams are continuing their reciprocating motion,
the suction pipe of each pump is furnished with an efficient stop-cock, as
shewn at G, Figures 1 and 3, by the simple shutting or opening of which
these punips may be thrown in or out of effective working, or the quantity of
gas or air they draw and deliver may be regulated.
Having thus described the nature of our Invention and the manner of
performing the same, we would have it understood that we make no claim to
the separate mechanical parts. What we claim is,-
First, the combining the vessels B and C and apparatus connected there-
with, substantially as herein described.
Secondly, we claim the combination with a mixing vessel B of apparatus
such as is herein described and shewn with reference to Figures 2 and 6, for
mixing dough; and,
Thirdly, we claim the combined arrangement of pumps, steam engine, and
apparatus working therewith, substantially as described with reference to
Sheet 2 of the Drawings.
In witness whereof, we, the said Robert Luke Howard and John
Dauglish, have hereunto set our hands and seals, this Twelfth day of
April, in the year of our Lord One thousand eight hundred and
sixty-five.
ROBERT LUKE HOWARD.
(L.S.)
JOHN DAUGLISH.
(L.S.)