CERTAIN IMPROVEMENTS IN BAKERS' OVENS
Year: 1857

page_text: LETTERS PATENT to Alfred Vincent Newton, of the Office for Patents,
66, Chancery Lane, in the County of Middlesex, Mechanical
Draughtsman, for the Invention of "CERTAIN IMPROVEMENTS IN BAKERS'
OVENS," A communication.
Sealed the 26th January 1858, and dated the 27th August 1857.
PROVISIONAL SPECIFICATION left by the said Alfred Vincent Newton
at the Office of the Commissioners of Patents, with his Petition, on
the. 27th August 1857.
I, ALFRED VINCENT NEWTON, of the Office for Patents, 66, Chancery
Lane, in the County of Middlesex, Mechanical Draughtsman, do hereby
declare the nature of the said Invention for "CERTAIN IMPROVEMENTS IN
BAKERS OVENS," to be as follows:-
This Invention relates to the application to ovens of a certain novel
system of endless suspension chains, for supporting trays of bread or
other substance during the baking process. These chains move
vertically, and convey the bread from one or more doors, through which
it is introduced to the oven to be baked, to another door or doors through
which it is withdrawn when sufficiently baked, the time occupied in
such conveyance being just sufficient for the baking process, which is
made continuous for any length of time by the introduction of new
supplies as fast as the discharges take place. The oven is thus kept
constantly filled with the bread or other substance at progressive stages

page_text: of the baking process. For the facility of its introduction to and with-
drawal from the oven, the bread or other substance to be baked is placed
on cars or trays, provided with wheels or runners, to run on suitable
tracks attached to the endless chains.
.
And the Invention further consists in a certain construction of these
cars or trays, and in certain automatic contrivances for drawing said
cars or trays into and expelling them from the oven; and in certain
means employed outside the oven to discharge the cars or trays after
they have left the oven; and in certain means of conveying said cars or
trays outside the oven from the doors by which they leave the oven to
the doors by which, after being reloaded, they are introduced to the oven
again.
The Invention also consists in certain automatic means of opening and
closing the doors of the oven at the proper intervals of time, for the
admission and discharge of the cars or trays.
And, lastly, the Invention consists in certain automatic contrivances
for regulating the temperature of the oven.
The car bodies or trays are constructed of metal frames, with tiles or
their equivalents supported therein. These trays are drawn into the
oven by rack bars, carrying spring tongs at their inner end, and working
through an opening or openings in the back of the oven or opposite side
thereof to the receiving doors. When thrust forward, the spring tongs
catch into hooks on the cars or trays, and at their return motion draw
the trays one by one into the oven. A similar provision is made for dis-
charging the trays from the oven when the baking is completed.
Motion is. communicated to the rack bars by means of crank rods,
segment racks, and spur pinions. In order to convey the cars or trays
from the door or doors through which they are discharged from the
oven to a door or doors through which, after being unloaded and re-
loaded, they are returned into the oven, carriages are provided, which
run to and fro at proper intervals between the receiving and discharging
doors outside of the oven.
These carriages are furnished each with a tilting frame, to facilitate
the unloading of the cars or trays after they have been discharged from
the oven. Attached to opposite ends of these carriages are chains, which
are connected to chain wheels that receive a reciprocating axial motion
from crank levers, through the intervention of segment racks and pinions,
and thus the requisite traverse motions are imparted to the carriages.
The receiving and discharging doors are caused to open at proper
intervals for the admission and discharge of the cars or trays from the
oven, by mechanical means, similar to that employed for working the
rack bars, which draw in and discharge the loaded trays.

page_text: A
An equivalent automatic arrangement is also provided for operating
a damper or dampers in the outlet flues of the oven to regulate the
temperature of the oven, such mechanism being set in action by a
tension bar contained in the oven, and therefore subject to contraction
or expansion, according to the variation of temperature therein.
current of cold air is admitted through the oven to the chimney, to
reduce the temperature of the oven when the action of the flue dampers
fails to reduce it sufficiently, by means of suitable openings, and a pipe.
or passage leading to the chimney and governed by dampers.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Alfred Vincent Newton in the Great Seal Patent Office
on the 27th February 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, 1, ALFRED
VINCENT NEWTON, of the Office for Patents, 66, Chancery Lane, in the
County of Middlesex, Mechanical Draughtsman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-seventh day of August, in the year of
our Lord One thousand eight hundred and fifty-seven, in the twenty-first
year of Her reign, did, for Herself, Her heirs and successors, give and
grant unto me, the said Alfred Vincent Newton, Her special license that
I, the said Alfred Vincent Newton, my executors, administrators, and
assigns, or such others as I, the said Alfred Vincent New-
ton, my 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 law-
fully might make, use, exercise, and vend, within the United King-
dom of Great Britain and Ireland, the Channel Islands and Isle of
Man, an Invention for "CERTAIN IMPROVEMENTS IN BAKERS' OVENS," being a
communication from abroad, upon the condition (amongst
others) that I, the said Alfred Vincent Newton, by an
instrument in writing under my hand and seal, 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 I, the said Alfred Vincent Newton, 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, reference being had to the Drawings here-

page_text: unto annexed, and to the letters and figures marked thereon (that is
to say):-
This Invention, as communicated to me by my foreign correspondent,
relates to the application to ovens of a certain novel system of endless
suspension chains, for supporting trays of bread or other substance during
the baking process. These chains move vertically to convey the bread
from one or more doors through it is introduced to the oven to be baked;
to another door or doors through which it is withdrawn when sufficiently
baked, the time occupied in such conveyance being just sufficient for
the baking process, which is made continuous for any length of time,
by the introduction of fresh charges of dough as fast as the discharges
take place. The oven is thus kept constantly filled with the bread or
other substance at progressive stages of the baking process. For the
facility of its introduction to and withdrawal from the oven, the bread
or other substance to be baked is placed on cars or trays, provided
with wheels or runners, to run on suitable tracks attached to the end-
less chains.
The Invention further relates to the construction of these cars or
trays, and to certain automatic contrivances for drawing the cars or
trays into and expelling them from the oven; also to certain means em-
ployed outside the oven for discharging the cars or trays after they have
left the oven; and also to certain means of conveying the cars or trays
outside the oven from the doors by which they leave the oven to the
doors by which, after being reloaded, they are introduced to the oven
again.
The Invention also relates to certain automatic means of opening and
closing the doors of the oven at the proper intervals of time, for the
admission and discharge of the cars or trays.
And, lastly, to certain automatic contrivances for regulating the
temperature of the oven
The Invention is illustrated in the accompanying Drawing, in which
Fig. 1 is a front elevation of an oven and all its appendages; Fig. 2 is
an end elevation of the same, as it would be seen when looking to the
right of Fig. 1; Fig. 3 is a back elevation of the same; Fig. 4 is a vertical
section, in a plane parallel with Fig. 1; Fig. 5 is a vertical section
parallel with Fig. 2, nearly in planes indicated by the lines x, x, in
Figures 1, 3, and 4; Figures 6, 7, 7, 8, 9, 10, 11, and 12, are detail
views, which will be herein-after referred to and explained. Similar
letters of reference indicate corresponding parts in each of the several
Figures.
A is the oven, built of brickwork or masonry, and strengthened with
ifon plates of quadrangular form in its transverse section, having up-

page_text: right sides, an arched roof, and an arched bottom, with its fireplace. K
under the bottom. This fireplace has bridge walls a and b on each side,
over which the products of combustion have to pass in traversing the"
entire bottom of the oven to reach the two main horizontal flues c, c,
from whence they pass through a number of upright fire-clay pipe flues
d, d, which line the sides of the oven, and communicate with two hori-
zontal main flues e, e, close to the roof. The flues e, e, are intended to
enter a connecting flue outside the oven, communicating directly with
the chimney; k is the fire door at the back of the oven.
B, B, B³, are three pairs of upright endless chains within the oven,"
fitted to run on chain wheels C, C*, C¹, C¹*, C2, C2*, which are secured
on three pairs of parallel horizontal shafts D, D*, D¹, D¹*, D³, D2*, which
are fitted to rotate in suitable bearings in plates f, f. Thes plates are
secured to the front and back of the interior of the oven and are stayed
by stays i, i, see Fig. 4. One pair D, D*, of the said shafts is arranged
with their axes in a vertical plane passing through the centre of the
oven, one shaft near the top and the other near the bottom of the oven;
and the other two pairs have their axes arranged in vertical planes at
equal distances from the central pair on opposite sides thereof near the
ends of the oven, and at corresponding elevations, as shewn in Fig. 4.
Each pair of shafts carries on its four chain wheels one pair of endless.
chains, and the chains and wheels are arranged nearly close to the back
and front of the oven, as is shewn in Fig. 5. The endless chains are
kept in upright positions between their respective wheels by means of
upright projections g, g, (see Fig. 4,) on the two plates f, f, which pro-
jections enter and fit easily between the sides of the chains. The two
endless chains which constitute one pair, that is to say, the two that are
hung on the same pair of shafts, are connected together at equal dis-
tances by horizontal bars h, h, which are bolted to or cast with alternate
links j, j, of the two chains, as shewn in Fig. 4, and further illustrated
in Figures 11 and 12, the former of which Figures is a front view, on
a larger scale than Fig. 4, of three lengths of one of the chains, ex-.
hibiting the bars h, h, in section, and the latter is a side view of three
links of each chain of one pair and two connecting bars, on a scale to
correspond with Fig. 11. The bars h, h, which it will be understood
are on the outer faces of the chains, constitute tracks extending from
the front to the back of the oven to support cars or trays E, E, E, E, on
which the bread or other substance to be baked is run into and from the
oven and supported while in the oven undergoing the baking process,
one side of each car being supported by a bar h on the straight portion of
the central pair of chains B, and the other by a bar h on the straight por-
tion of one of the side chains B or B2. The shafts of the chains are so
geared by their driving gear, herein-after to be described, that each ban

page_text: ḥ on the straight portions of the central pair of chains B, that is to say,
the portions that are free of the chain wheels, is exactly on the same
level as a bar of the nearest side of the nearest outer pair of chains B' or
B³, so as to support the cars in a perfectly horizontal position, as is
illustrated in Fig. 4. The distances between the several bars h, h, taken
vertically on the straight portions of the chains is only just sufficient
to allow about from four to eight inches of clear space between the tops
of the loaves or other articles on the cars and the bottoms of the cars
above, so that as many cars as possible may be contained in the oven
at the same time. The chains have severally a continuous motion in
such direction, indicated by arrows in Fig. 4, that the cars supported
on the chains B, B2, are always descending, and those supported on
the chains B, B', always. ascending. The plates f, f, which line the
back and front of the oven are furnished with upright projecting pieces
86, the faces of which serve to guide the ends of the cars in their ascent
and descent.
F, F, F, F*, are four vertically sliding doors fitted to opening made
in front of the oven, and of a height and width sufficient for the cars
E, E, when loaded with bread or other material to pass through to and
from the oven; two of the openings, to which are fitted the doors F and
F*, are situated opposite the space between the chains B and B', and
the other two openings, to which are fitted the doors F' and F*, are
situated opposite the space between the chains B and B', the two
openings belonging to the doors F and F* being on the same level with
each other, or nearly so, near the top of the straight portions of the
chains, and the other two belonging to the doors F¹ and F* being on
the same level with each other, or nearly so, near the bottom of the
straight portions of the endless chains. The bottoms of the door
frames H, H, H, H, which line the openings J, J, to which the doors
are fitted, are provided with raised tracks o, o, (see Fig. 5), correspond-
ing in distance apart and position with the tracks h, h, for the wheels
q, q, of the cars E, E, to run on, on their way into and from the oven.
The doors F and F' admit the cars to the oven with the unbaked bread,
and those F*, F¹*, serve for the exit of the cars with the bread after
it is baked. The velocity of the movement of the chains is such, that
the time occupied by the several cars in their movement from the door
F to the door F*, or from the door F¹ to the door FI* is just sufficient
for the baking process.
.G, G*, G¹, G*, are four horizontal shafts fitted to work in bearings
in brackets 1, 1, secured to the front of the oven, one of the said shafts
being situated above each of the four doors, and each carrying a toothed
sector. m.gearing with an upright toothed rack n attached to its re-

page_text: spective door, for the purpose of opening and closing the doors by proper
movements imparted to the shafts, herein-after described, at proper
intervals of time for the entrance and exit of the cars as the track bars
h, h, severally arrive on a level with the bottoms of the openings.
I, I, are two iron platforms, situated in front of the oven at such a
distance below the openings J, J, as is convenient for men standing
upon the platforms to load the cars when the latter are properly sup-
ported, at a proper level to run into the oven. These platforms, which
are level with two floors of the bakehouse, are stayed together by pillars
M, M, and have upon them tracks p, p, parallel with the front of the
oven (see Figures 1, 2, and 5), along which tracks travel two wheeled
carriages L, L*, upon which the cars E, E, are received as they leave
the oven by the discharging doors F*, F*, and by which they, after
having been unloaded, are conveyed to positions opposite the receiving
doors F, F', to be in readiness to enter the oven again when the latter
doors are opened at the proper time. The movement of the carriages
along the tracks p, p, for the above purpose is effected through the
agency of chains t, t*, t', t¹*, (see Fig. 1,) which are operated by means
herein-after described, and the movements are limited by stationary stops
26, U. The carriages L, L*, which are both alike, are provided re-
spectively with a tilting frame r, 7, 1, 2, the two side rails r, r, of
which, when the carriage is opposite one of the doors, form continua-
tions of o, o, and of any of the tracks h, h, that may happen to be at the
right level, so that the cars may run from the oven directly on to the
rails 7, r, or vice versa. These ends of the rails r, r, which are farthest
from the oven are turned up, as shewn in Figures 2 and 5, to stop the
wheels q, q, when the cars or trays have run far enough out of the oven
to allow the doors to close. The tilting frame r, r, r', r¹, of each of the
carriages L, L*, is balanced on two pivots s, s, which are supported in
the ends of the carriage, but it is, so arranged that when a loaded tray
is received upon it from the oven, the outer end of the frame will be
overbalanced by the weight of the tray, which will be caused to assume
an inclined position, and discharge the bread or other baked substance
into a suitable receptacle, while the tray is retained upon the rails r, r,
by their turned-up ends. This operation of the tilting frame is illus-
trated in Fig. 10, which represents a vertical section of the discharging
door F*, with the carriage L* opposite to it, said carriage having re-
ceived a tray which has just tilted the frame r, r, r, r¹, and thus been
caused to discharge its bread. The same carriage is represented in the
same condition in red outline in Fig. 1. The tilting frame r, r', pol, got,
of each carriage is returned to a horizontal position while the carriage
is on its way from the discharging to the receiving door, by means of a

page_text: lever (see particularly Figures 5 and 10, but also Fig. 1), attached at
one end by a fulcrum pin v', to that side of the body of the carriage that
is farthest from the oven, and which has its other end supported in a
notch in an upright sliding piece v2, working in a guide attached to the
side of the body of the carriage nearest the oven. The upright sliding
piece has a wheel 3 attached to it, which runs on a rail v between
the rails p, p, said rail * having an upward inclination from the dis-
charging towards the receiving door, as shewn in Fig. 1. An antifric-
tion roller ve is attached to the tilting frame in a position between its
pivots s, s, and its outer end, see Fig. 5. When the carriage is opposite
the discharging door, the wheel 3 of the sliding piece v³ being at the
bottom of the inclination of the rail, allows the sliding piece to
occupy a low position relatively to the tilting frame, and the lever v
hangs down low enough to allow the tilting frame to come to the in-
clined position shewn in Fig. 10, but as the carriage runs towards the
receiving door, the wheels v³ in running up the inclined face of the rail
* causes the sliding piece' v² to lift the lever v gradually, and the said
lever coming in contact with the roller v6 lifts up the outer end of the
tilting frame and replaces it in the horizontal position, and holds it in
that position with the tray upon it opposite the receiving door, in readi-
ness to be reloaded and run into the oven at the proper time. When the
tilting frame is in a horizontal position, the end nearest the oven has a
bearing upon a rest v³ attached to the carriage. The loading of the
cars or trays E is performed by hand, as indicated at Fig. 5. w is an
aperture in the back of the oven, opposite the door F, to admit a pair
of spring tongs y attached to a long horizontal iron bar N, which is
fitted with rollers 2, 2, to run upon a stationary horizontal bar O, which
it attached at its front end to the back of the oven, and supported at its
rear end by an upright frame P, see Fig. 5. This bar N is furnished
with a toothed rock, gearing with a spur wheel 20, on a short hori-
zontal shaft 21, arranged in suitable bearings in brackets 22, 22, form-
ing parts of a large casting W secured to the back of the oven, which
shaft 21 is operated at proper intervals by means herein-after described.
to make the spur wheel act upon the rack, and drive the bar N quickly
through the oven every time a pair of rails h, h, of the chains B, B2,
arrive on a level with the tracks o, o, inside the door F, for the purpose
of seizing hold of the loaded tray of unbaked bread or other substance
that is at the time waiting opposite the said door, and cause it to return
as quickly, drawing the tray along the tracks o, o, and h, h, into the
oven. This operation of the bar N and tongs y is illustrated in Figures
5 and 8, the latter of which Figures exhibits a horizontal section of the
aperture J of the door F, and a plan of the bar N, and one of the cars

page_text: inside the oven and another outside. The stationary position occupied
by the bar N and tongs y, after having drawn a tray into the oven, and
while in waiting to run through the oven when the proper time arrives
to fetch another tray, is represented in Figures 5 and 8 in black out-
line, and their position at the time of just having seized a tray in red
outline. The tongs have latches at their extremities which spring past
a double hook 23, which is provided on the back of each tray, and
these latches and the hook 23 attach the tray to the bar N. After the
tray has been drawn into the oven, it is liberated from the tongs by its
descent with the chains, while the bar and tongs remain in the position
shewn in black outline, and as soon as the tray has moved entirely below
the tongs, the latter are at liberty to run in to fetch another at the
proper time. w' is an aperture like w in the back of the oven opposite
the door F', to admit a pair of spring tongs y', attached to a bar N¹
like N, sliding on a similar bar O¹, attached to the oven and to the
frame P. The bar N¹ and tongs y' are operated substantially like the
bar N and tongs y, to fetch the trays through the door F' on to the
ascending tracks h, h, of the chains B, B', the only difference in the
operation being that the hooks 23 of the trays liberate themselves from
the tongs y by an upward instead of a downward motion; 21' is the
shaft, and 20 is the spur gear by which the bar N' is driven into and
out of the oven, the said shaft being like that, 21, hung in bearings
in brackets 221, 22', on the casting W; w* is an aperture in the back
of the oven opposite the door F*, to admit a bar N* which is provided
with a broad T shaped end, and runs on a bar O* that is similarly
arranged to O and O', the said bar N* being for the purpose of pushing
out the cars or trays E, E, through the open door F* as the descending
tracks h, h, of the chains B, B2, severally arrive at a proper level. The
bar N✶ is driven through and drawn back out of the oven in a similar
manner to the bars N and N', by means of a spur wheel 20* on a short
horizontal shaft 21*, supported in bearings in brackets 22*, 22*, on the
casting W; the spur wheel 20* gearing with a rack on the under side
of the bar. w* is another aperture in the back of the oven, situated
opposite the door F¹*, and serving to admit a bar N* like N*, that is
fitted to run on a bar O* similarly arranged to O, O', O*, the bar N*
being for the purpose of pushing the cars out through the open door F¹*,
as they are severally brought to a proper height by the ascending move-
ment of the chains B, B'. The bar N* is driven through the oven for
the above purpose, and drawn back again in a similar manner to N*,
by means of a spur wheel 201* gearing with a rack on its upper side,
the spur wheel 201* being secured to a short horizontal shaft 21**, fitted
to run in bearings in brackets 22'* on the casting W. Fig. 9 represents

page_text: a plan of the bar N*, and that Figure also serves to illustrate the form
of the bar N*, as that bar only differs from N¹* in having its toothed
rack on the under side. The bars N', N*, N*, are all like N provided
with rollers z, z, to run on their guide bars O', O*, O¹*. All these bars
are shewn in the back view of the oven, Fig. 3, where the frame P is
omitted, to expose the driving mechanism by which the movements of
the chains, doors, cars, and carriages are effected.
Qis the main shaft from which the movements of all the machinery
belonging to the oven are derived. This shaft is supported in a hori
zontal position parallel with the back of the oven, in bracket bearings
24, 24, on the casting W, and having a rotary motion at a slow speed
imparted to it through a large spur wheel Q₁, secured on one end of
it from a pinion 25* on a shaft 25, which works in bearings attached
to a strengthening plate 26 at one corner of the back of the oven,. and
which shaft is intended to derive inotion through a belt and two cone
pulleys from the shaft of a steam engine or other first mover. The
main shaft Q is furnished with three bevél wheels R, R', R³, gearing
with three other bevel wheels S, S', S', on three upright shafts T, T', T²,
the bottoms of which rest in steps in three of the brackets 24, and the
upper ends of which work in bearings in three brackets 30 on the cast-
ing W; and the shafts T, T¹, T³, carry three bevel pinions U, U¹, U³,
gearing with three large bevel wheels V, V, V, on the rear ends of the
three chain shafts D*, D*, D**. The above-described train of bevel
gearing thus serves to impart motion from the main shaft to the chains
B, B1, B2.
X is a shaft arranged above and parallel with the main shaft. Qin
bracket bearings 27 in the two corner plates 26 and casting W, and
receiving rotary motion at the same velocity as the main shaft Q through
a spur wheel 28 fast upon it from another spur wheel 29 on the main
shaft Q. The shaft X is furnished at one end (seen to the left hand of
Fig. 3 and right hand of Fig. 1) with a cam 31, whose form is visible
in Fig. 2, that rotates in contact with a roller 32 (see Figures 2 and 3)
at the end of an arm 33, which is fitted to swing on a pivot 34 secured
in the corner plate 26, and which is connected by a rod 35 with a short
arm 36, that is fast on the end of the shaft G. The above-mentioned
cam, by its rotary movement in contact with the roller, gives, through
the arm 33, rod 35, and arm 36, the necessary movement to the shaft
G, for the sector m by its action on the rack n, to open the oven door F
at the proper time for the rod N with its tongs y to run forward and
draw a loaded tray from the carriage L into the oven. The cam only
keeps the door open long enough to admit the tray. The door closes
again by its own weight, assisted by the weight of the rack n, sector m,

page_text: arm 33, and rod 35, all of which are so disposed as to make the roller
descend the offset of the cam. At the opposite end of the same shaft X
there is a cam 31*, which is formed like and operates in a similar
manner to the cam 31 upon a roller 321* attached to an arm 331* (see
Fig. 3), which swings on a pivot 34*, and is connected by a rod 35¹*
with an arm 36* on the shaft G*, the said roller arms and rod being
arranged like those just above described, as being operated upon by
the cam 31, and being operated upon in a similar manner to move the
shaft G* to open the door F¹* by means of the proper sector m and
rack n at the proper time for a tray of baked bread or other substance
to be pushed by the rod N* out of the oven on to the carriage L.
X is a shaft like X, arranged below and parallel with the main
shaft Qin bracket bearings 27' in the two corner plates 26 and casting
W, and receiving motion at the same speed as the main shaft Q through
a spur wheel 28' fast upon it from the spur wheel 29, which drives the
shaft X. The shaft X' is furnished at the end seen to the left end of
Fig. 3, with a cam 31* like the cams 31 and 311*, that rotates in contact
with a roller 32* attached to the end of an arm 33* (see Figures 2 and 3),
which works on a fixed pivot 34* secured in the corner plate 26, and
which is connected by a rod 35* with an arm 36* on the shaft G*. The
roller 32* arm 33*, rod 35*, and arm 36* are operated upon by the
cam 31* in a similar manner to that in which the corresponding rollers,
arms, and rods in connexion with the cams on the shaft X are operated,
to give the necessary movement to the shaft G* to cause the proper
sector m and rack n to open the door F* at the proper time to allow the
bar N* to push out a tray of baked bread or other substance from the
oven on to the carriage L*. At the opposite end of the same shaft
X' there is a cam 31' (like 31, 31¹*, and 31*) which operates in a similar
manner to those cams upon a roller 32', arm 33', rod 35', and arm 36',
to give to the shaft G' the movement necessary for the proper sector m
and rack n to open the door F at the proper time for the bar N' with its
tongs y to pull a loaded tray from the carriage L* into the oven. All
the cams above described are of such form and so arranged, and the
doors are also so arranged, that one door is closed before another is
opened, and only one is allowed to be open at a time, and thus no
draughts of cold air can be induced through the oven by the opening of
the doors. The doors open in the following order,-F, F', F*, F*.
The shaft Q, in addition to the spur and bevil wheels before described,
carries at its opposite ends two cams 37 and 38, for the purpose of trans-
mitting motion to the chains t, t*, t', t*, by which the carriages L, L*,
are caused to convey the trays from the discharging to the receiving
doors. The mechanism through which motion is transmitted from the

page_text: cams to the chains is as follows:-The two chains t, t¹*, connected with
the carriage L, are respectively attached in a secure manner to two
wheels 39 and 391*, upon two shafts 40 and 40¹*, which are arranged
in bearings 41 and 41*, supported by the platform I, and these shafts
carry two bevil wheels 42, 42*, which gear with two bevil toothed
sectors 43, 43*, on a long horizontal rock shaft 44, which is arranged
parallel with the front of the oven just above the platform I, in bracket
bearings 45, 45, attached to the two front corner plates 46, 46, of the
oven. The sector 43 is connected by a rod 47 with an arm 48 (see
Figures 2 and 3), which hangs on a fixed pin 50, secured in one of the
back corner plates 26, and carries at its lower end a roller 49, which
rests against the cam 37, and the sector 43¹* is connected similarly to
that 43, by a rod 47¹*, with an arm 48¹* (see Fig. 3), which carries a
roller 49, that rests against the cam 38. The forms of the two cams
37, 38, and the arrangement of the several parts of the mechanism
above described are such, that the two sectors are operated upon by
their respective cams to move both shafts 40, 40*, through the bevil
wheels 42, 42*, in similar directions, so that as one of the chain wheels
39 or 39 winds up its respective chain tor t*, the other lets off its
respective chain; and the forms of the two cams and their arrangement
upon the shaft Q are such, that through the operation of the mechanism
above described upon the chains t, t*, the carriage L is caused to arrive
opposite the door F¹* just before that door opens, and that after a tray
of baked bread has been run out on to the carriage, the latter is almost
immediately run along its track p, p, to the door F, where it remains
stationary till the latter door has opened and the bar N with its tongs y
has drawn the tray into the oven; the time that the carriage is stationary
opposite the latter door being sufficient for the car to be loaded by an
attendant. The two chains t*, t', which are connected with the carriage
L*. are connected with two chain wheels 39*, 39¹, like those 39, 39¹*,
before described, the wheels being secured upon two shafts 40*, 40¹,
which are arranged in bearings 41*, 41', supported by the platform I*,
and these shafts carry two bevil wheels 42*, 42', gearing with two
toothed sectors 43*, 43', on a long horizontal rock shaft 44*, which is
arranged parallel with the front of the oven, just above the platform I*
in bearings 45*, 45*, attached to the front corner plates 46, 46, of the
The sectors 43*, 43', are connected by rods 47*, 47', with two
pairs of arms 48*, 48', which hang on the axles of the rollers 49, 49¹*,
of the arms 48, 481*, and these arms 48*, 481, carry rollers 49*, 491,
which rest against the cams 37, 38, and are operated upon by them to
actuate the arms 48*, 48¹, rods 47*, 47', sectors 43*, 43', bevil wheels
42*, 42', shafts 40*, 40', chain wheels 39*, 391, and chains t*, t, in the
oven.

page_text: same manner as the mechanism before described for giving a similar
motion to the carriage L*, (that is to say,) to bring the said carriage
at the proper time opposite the discharging door F* to receive a tray
of baked bread or other substance from the oven, and then to run said
carriage across to the receiving door F', and keep it stationary in front
thereof till it has been reloaded and run into the oven again through the
latter door. It may be observed, that the hanging of the links 48*, 48',
through which the cams actuate the lower carriage upon the axles of
the rollers 49, 49¹*, of the arms 48, 48*, does not interfere with the
proper operation of either pair of arms, as the lower arms are so pro-
portioned that only one pair of arms is operated upon at a time by the
cams 37, 38, only one carriage being required to move at a time.
The shaft X, in addition to the cams 31, 31*, carries two cams 51, 52,
and two similar ones 51¹*, 52*, for the purpose of giving the necessary
motion to the shafts 21, 21*, before described, by whose spur wheels
20, 20, the bars N, N*, are operated, to draw the cars into and eject
them from the oven through the doors F, F*, and the shaft X' carries
two similar cams 51*, 52*, and two others 51', 52', for the purpose of
giving the necessary motion to the shafts 20*, 20¹, by whose spur wheels
21*, 21', the bars N*, N¹, are operated to draw the cars into and eject
them from the oven through the doors F*, F'. I will first describe the
arrangement and operation of the mechanism through which the cams
51, 52, act upon the shaft 21, and as the mechanism through which
the other cams 511*, 521*, 51*, 52*, 51', 52', operate is exactly the same,
it will merely require to be pointed out on the Drawing. Above the
shaft 21 there is a rock shaft 53, working in bearings in two brackets
54, 54, attached to the casting W, the said rock shaft carrying a toothed
sector 55, (best shewn in Fig. 5, but also shown in Fig. 3,) gearing with
a small spur wheel 64 on the shaft 21. This toothed sector has con-
nected to it by wrist pins 63, 63, on opposite sides of its shafts two rods
56, 57, to the lower ends of which are attached two rollers 58, 59, one
of which rests on the cam 51, and the other on the cam 52, said rods
being held in proper condition for the cams to act against their rollers
by two links 60, 61, which swing on a pin 62, secured in a stationary
frame Y, that is secured to the back of the oven. The cam 51 acting
upon the roller 58 and rod 56 moves the sector 55 in the proper direc-
tion for it to turn the wheel 64, and consequently the shaft 21, in the
direction required for its wheel 20, acting upon the rack of the bar N to
drive the said bar N forward through the oven, and the cam 52 acting
upon the roller 59 and rod 57 moves the sector 55 in the proper direc-
tion for it to turn the wheel 64, and consequently the shaft 21 and the
wheel 20, in the opposite direction, to draw back the bar and draw a

page_text: tray into the oven. The relative forms of the two cams 51, 52, are such
that they hold the sector steady, whether in motion or at rest, neither
cam allowing the sector to move any faster than the other requires.
Above the shaft 20¹* is the rock shaft 53*, working in bearings 54¹*,
54*, and carrying the sector 55*, gearing with the wheel 64'* on the
shaft 21*, the said sector having connected with it the two rods 56¹*,
57, carrying the rollers 58*, 591*, which rest upon the cams 51*, 52¹*,
and the said rods being held in proper position by the two links 60¹*,
61* Below the two shafts 21* and 21¹ are arranged the two rock
shafts 53* and 53', in bearings 54* and 54', said rock shafts carrying
the sectors 55* and 55', which gear with the spur wheels 64* and 64',
on the shafts 21* and 21', and have connected with them the rods 56*,
57*, and 56¹, 57', whose rollers 58*, 59*, and 58', and 59', bear against
the cams 51*, 52*, and 51', 52'. The links 60, 611*, (see Fig. 5,) which
keep the rods 56* and 57* in proper position, and the similar ones (not
shewn) which keep the rods 56¹ and 57' in proper position, are attached
to fixed pins, as shewn at 62* (Fig. 5), secured in a frame Z, at the back
of the oven.
The cars or trays E, E, are constructed with bottoms of tile or soap-
stone, but preferably of fire-clay tiles; the superiority of such materials
for the interior portions of ovens is well understood by bakers. The con-
struction of the bodies of the cars is well illustrated in Figures 6, 7, and
7*, the first of which Figures is a plan, and the next a longitudinal
section of one of the cars on an enlarged scale, and Fig. 7* is a longi-
tudinal section on a still larger scale of one of the fire-clay tiles. 65
is a quadrangular cast-iron frame constituting the sides, front, and back
of the car body, and strengthened by transverse bars 66, at equal
distances. These bars are of the same depth as the front of the car,
but of a much less depth than the back and sides of the car, as shown
in Fig. 7. 67, 67, are a number of small square frames of light wrought
iron, fitting between the bars 66, as shewn in Fig. 6, where some of the
tiles are omitted or broken away to expose the frames. These frames
67 are of a depth only about one half that of the bars 66, to which they
are rivetted or otherwise secured, so as to leave about one half the depth
of the latter standing above them, as shewn in Fig. 7. The tiles 68 are
made of the same size as the exteriors of the frames 67, but each with a
lip 15 (see Fig. 7*) on one side to lap over and rest each on one of the
bars 66, while the four sides of the tile are supported by the frames 67.
The two sides and back of the frame 65 of the car stand up some
distance above the tile bottom, which not only strengthens the car but
prevents the loaves or other articles slipping off in any direction, except
at the front, where the frame is covered by the tiles, and no obstruction

page_text: is offered to the slipping off of the loaves or other articles, as shewn in
Fig. 10, when either of the carriages L, L*, is tilted with the car upon
it. By the above construction of the cars, provision is made for their
discharging themselves, and the tiles which form a close flat bottom
are confined securely in place, and if one or more should happen to be
accidentally broken, the whole ones cannot be so far displaced as to fall
out; and what is still more important, the bottoms of the tiles are left
almost entirely exposed, so that the tops of the loaves or other articles
below them are subjected to a gentle radiated heat from them; whereas
if the cars had iron bottoms, the loaves or other articles below would
have their tops scorched by the intense radiation of heat therefrom
before they were properly baked. Instead of cars on wheels, trays con-
structed in a substantially similar manner to the bodies of the cars
above described, and slid into and from the oven, might be used, but
generally the cars will be more convenient than the sliding trays.
In order to provide for the regulation of the temperature of the oven
and to economise fuel, each of the outlet flues e, e, is fitted with a
butterfly damper" 69, (see Figures 2, 3, and 5,) which is made self-
acting by the following means:-70 (see Figures 4 and 5) is a thin flat
bar of iron or other metal extending right across the upper part of the
oven, and firmly secured at its ends by bolts 71 to the ends of the oven.
This bar is longer than the distance between the points of attachment of
its ends, and has to be deflected to get it into its place, such deflection
being made in an upward direction from its ends; this deflection is in-
creased more or less by its expansion when the oven becomes hot. At
its highest part the bar 70 passes through a slot in the front end of a
lever 72, which works through a hole in the back of the oven on a
fulcrum 73 (see Fig. 5). The outer or rear end of this lever carries a
stud 74 on one side (see Fig. 5), which stud always bears upon an arm
77, secured to a light horizontal shaft 75, which is fitted to turn in
bearings in brackets 76, 76, (see Figures 2, 3, and 5,) secured to the
back of the oven. This shaft 75 has attached to it a weighted arm 78,
by which the arm 77 is caused to press upwards against the stud 74 on
the lever 72, and said shaft carries two smaller arms 79, 79, in which
are secured studs, which, by the weight of the arms 78, are caused to
support the weighted arms 80, 80, which are secured to the pivots of
the two dampers 69. The weight of the arms 78 is only just sufficient
to cause the arms 79, 79, to hold up the weighted arms 80, 80, of the
dampers, and to keep the arm 77 pressing up against the stud 74 of the
lever 72. The degree of opening of the dampers 69 depends upon the
degree to which the bar 70 is expanded. The dampers are so set that
when the oven is at the lowest baking temperature they will be wide

page_text: open. As the temperature of the oven increases beyond this point the
increasing deflection of the bar 70, consequent upon its expansion, causes
the said bar to raise the inner end of the lever 72, by which means the
stud 74, at the outer end thereof, is caused to depress the arm 77, and
turn the shaft 75 in such a direction that the arms 79, 79, descend and
allow the descent of the weighted arms 80 of the dampers, and as soon
as these latter arms descend, the dampers begin to close, and this opera-
tion continues as the heat of the oven continues to increase, until the
dampers are quite closed. As the temperature falls again an opposite
effect is produced, the bar 70 straightening itself by its contraction and
drawing down the inner end of the lever 72, and allowing the arm 77 to
rise, and thus permitting the weighted arm 78 to raise the arms 79 and
80, and open the dampers. The above regulating apparatus can be so
adjusted as to close the dampers entirely at any given temperature, but
as it may sometimes occur that the temperature of the oven will con-
tinue to rise after the communication from the fire to the chimney is
cut off by the dampers, an opening 81 (see Figures 3 and 4) in the
lower part of the back of the oven, and a pipe 82, communicating be-
tween the upper part of the oven and the chimney, are provided for the
admission of an upward current of cold air through the oven to the
chimney: The admission of such current, however, is not to commence
till the flue dampers have been quite closed and the heat rises to such
a degree that the bread or substance being baked is in danger of scorch-
ing, when the cooling is effected by opening two dampers 83, 84, one
fitted to the opening 81, and the other to the pipe 82, the said dampers
being connected together by a rod 85, so as to operate simultaneously.
A weight applied to the lever of the upper damper 84 serves to keep
both dampers closed till the arm 78 on the shaft 75 continues to rise
after the closing of the flue dampers; but the arm 78, by a continued
ascent, acts upon the lever of said damper 84, to open both it and the
damper 83.
Having described an oven in which all the principles of the Invention
are fully carried out, I would remark that by using five sets of chains
instead of three, as above described, four series of cars may be employed,
viz, two ascending and two descending series, but such an arrangement,
it is obvious, will require twice the number of doors, and the duplica-
tion of the greater portion of the apparatus. Two sets of chains may
also be used with a single series of ascending or descending cars, but it
is obvious that with the two sets of chains the principles of the Inven-
tion would be but imperfectly carried out, and the oven must then, of
necessity, be only to a certain extent automatic in its operation. Instead
of using only two endless chains on each pair of chain shafts, sets con-

page_text: sisting of a greater number may be employed to sustain the rails or track
bars h, or chains may be so constructed with very broad links that a
single chain on each pair of chain shafts will do the duty performed by
the pair of chains described.
Having now described the nature of the Invention as communicated
to me by my foreign correspondent, I wish it to be distinctly understood
that I do not confine myself strictly to the precise details herein
described, as such may be varied or modified to a considerable extent
without departing from the principles of the Invention, but what I
claim under the above in part recited Letters Patent is,-
Firstly, the employment of two or more pairs or sets of upright end-
less chains or single endless chains arranged on parallel shafts, which
are placed side by side, and carrying rails or their equivalents, to
receive and support one or more series of cars or trays which contain the
bread or other substance to be baked and operated in any way substan-
tially as herein described, to convey the bread through the oven with
an ascending or descending motion from a door or doors through which
the said cars or trays enter or leave the oven.
Secondly, constructing the car bodies or trays of metal frames with
tiles or their equivalents supported therein, substantially as herein
described.
Thirdly, the employment of a bar or bars N, N¹, carrying spring
tongs working through an opening or openings in the back of the oven
or opposite side thereof to the receiving doors, and operating in com-
bination with double hooks or their equivalents, on the cars or trays,
substantially as herein described, for the purpose of drawing the cars or
trays into the oven on the rails or supports provided for them.
Fourthly, the employment of a bar or bars working as described
through an opening or openings in the oven opposite to the discharging
doors, for the purpose of pushing the cars or trays from the rails or other
supports, and out of the oven.
Fifthly, the employment of the mechanical means herein described
or their equivalent for operating the devices, by which the cars or trays
are drawn into and pushed out from the oven.
Sixthly, the employment of a carriage or carriages running to and
fro at proper intervals, between the receiving and discharging doors
outside of the oven, to convey the cars or trays from the door or doors,
through which they are discharged from the oven to a door or doors,
through which, after being unloaded and reloaded, they are returned
into the oven.
Seventhly, furnishing the carriages above mentioned each with a tilt-
ing frame, operating substantially as herein described, to effect the un-

page_text: loading of the cars or trays after they have been discharged from the.
oven, and to return them to a suitable position for reloading before they
are returned into the oven.
Eighthly, the employment of the mechanical means herein described
or their equivalent, for the purpose of giving the necessary movement
to the carriages outside of the oven.
.
Ninthly, the employment of the mechanical means herein described
or their equivalent, by which the receiving and discharging doors are
opened at proper intervals for the admission and discharge of the cars
or trays from the oven.
Tenthly, the employment of the mechanical means herein described
for operating a damper or dampers in the outlet flues of the oven, to
regulate the temperature of the oven.
Eleventhly, the admission of a current of cold air through the oven
to the chimney to reduce the temperature of the oven when the action
of the flue dampers fails to reduce it sufficiently, by means of an open-
ing to admit the cold air, and a pipe or passage leading to the chimney,
and the arrangement of dampers, substantially as herein set forth.
In witness whereof, I, the said Alfred Vincent Newton have here-
unto set my hand and seal, the Twenty-seventh day of February,
in the year of our Lord One thousand eight hundred and fifty-
eight.
Witness,
J. W. MOFFATT,
66, Chancery Lane.
A. V. NEWTON. (L.S.)