Improvements in Drawplate Ovens, more particularly of the "Wieghorst " System.
Year: 1891

page_text: This Print is in accordance with the Original Specification as it stands after
Amendment (under Section 18 of the Patents, &c., Act, 1883), as allowed b▾
the decision of the Comptroller General of the 22nd day of February 1897.
Date of Application, 25th July. 1891
Complete Specification Left, 26th May, 1892-Accepted, 25th Oct., 1892
PROVISIONAL SPECIFICATION.
Improvements in Drawplate Ovens, more particularly of the
"Wieghorst " System.
I, PAUL PFLEIDERER, of the firm of Werner & Pfleiderer, of 86 Upper
Ground Street, London S.E., and of Cannstatt in Germany, Bakery Engineer, do
hereby declare the nature of my said invention to be as follows:-
--
This invention consists of improvements in drawplate ovens more particularly of
the "Wieghorst" system, I construct the rails which project from my ovens into
the bakehouse and on which my travelling baking plates are run in and out of the
oven so that they can easily be folded hinged pushed or telescoped out of the way
while the baking plates are in the oven and so as to be easily folded hinged or
pulled into position again when the baking plate is to be drawn out or 1 construct
the baking plate altogether without wheels or with wheels only at that end which
goes furthest into the oven and I connect the rails as it were with the drawplate
itself and mount the wheels or rollers all or in part on chairs fixed in the oven and
some of them so far in front out of the oven as the necessary equilibrium of the
drawplate will necessitate thereby and by so distributing the masses of the draw-
plate or by attaching loads or weights to the end going furthest into the oven 1
have it in my power to reduce the distance from which the outermost chair projects
beyond the front of the oven to a practical minimum or 1 mount these chairs with
drawplates supporting wheels or rollers on folding hingeing or telescoping jib
beams so as to have the facility of moving them almost entirely out of the way in
the bakehouse when they are not wanted for supporting the drawplates or I support
or suspend the drawplate from a rail or rails fixed to the top of the oven or ceiling
of bakehouse & provided with a sort of inverted trolley or travelling dog similar to
those of ordinary overhead travelling cranes. By these means I avoid all the
various kinds of rails or travelling supports grooves in the flour and carriages in
the bakehouse which have from time to time been contrived with the object of
avoiding the in most cases much less objectionable standards which are fixed in the
bakehouse and which have hitherto been so successfully used in the well known
"
type of " Wieghorst steam ovens. I also construct my drawplates with high
sides carried on hinges so that they may be flapped down when the bread is drawn
to facilitate unloading the baked bread and to avoid the necessity of loose setters
or guards requiring to be put on when the dough loaves are being set and I
sometimes arrange my rails for travelling plates on the trolleys by which they are
supported in a suitable way so as to be able to raise and lower them and with them
the "drawplates" which they carry for the purpose of decreasing or increasing
either the distance of the entire or sectional baking plates when in the oven or for

page_text: raising or lowering the plates when out of the baking chamber. When I provide
an opening at one end of the oven chamber only so as to be obliged to set the bread
at the same end as I draw it when it is baked I find it always very convenient to
fire my steam pipe ovens from the closed end running the pipes parallel with the
direction of the rails on which the drawplates run but if for any reason I have to
put the pipes crossways and fire as it were from the side the end of the oven being
built against a wall and pipes running parallel to it those situated close to the wall
are rather inaccessible or if for any other reason the heating pipes are difficult to
get at I provide them with clips or muffs, preferably one set of clips to every two
pipes and so situated in the oven chamber that they are accessible in order that the
adjustment of pipes longitudinally for regulating their heating surfaces may be
easily performed with a lever by a man or boy going inside or by a separate
mechanism which can be worked from outside consisting of an axle mounted on
bearers inside the oven and provided with cams or knobs working against the clips
or I provide openings in the end wall or in the furnace wall which I keep ordinarily
closed by bricks or other fire resisting materials but which can be opened for the
purpose of adjusting the pipes without breaking or cutting the wall. For this
purpose and for other reasons of convenience and solidity of my furnaces I construct
the backs of the same with a strong iron framework or bearers right along which
bearers are firmly anchored or bolted by at least 2 or three long anchors or tierods
for which it at the same time constitutes the washer or wallplate and I prefer to
make this frame or these bearers or beams of iron so as to serve at the same time
as a solid metallic support for the heads of screws by which the furnace door
frames and other fittings are fixed and which screws have hitherto always been
built into the wall and held in a less solid manner by bricks or mortar only and to
facilitate seeing the position of the furnace ends or heating surface ends of the
steam pipes I arrange small doors in the backwall of the furnace in the stokehole
proper at the end nearest the wall with provision to light up the flue spaces so that
from another door or doors which I provide outside the stokehole proper at right
angles to these illuminating doors in the stokehole one can see the ends of the
various pipes and the wire drawing elit for the fire gases and the top of the fire or
burning fuel these latter doors serving at the same time for cleaning the pipes and
flue from scot or ashes and for raking or adjusting the fuel which is so liable to get
unequally distributed over the whole length of the furnace from the ordinary fire
doors in the stokehole and with my large furnaces I provide horizontal steadying
piers or stays in the furnace flue of firebricks with an anchor or tie-bolt right
through from back of furnace to back of baking chamber and I sometimes
build my ovens in two or three so called "decks" i.e. several baking chambers are
built one on the top of the other in so many storeys at it were and all being heated
from one and the same furnace but in this case my novel plan is to run the rollers
and drawplates of these various decks or storeys at right angles to each other
wherever the situation of premises allows of it because by this arrangement I
obtain perfect freedom and indenpendence of one baking chamber from the others
for simultaneous manipulation of the drawplates of the various ovenchambers or
decks.
I further where the premises are favorable for the plan or admit of it run my
baking plates into the oven at one end and out of it at the other end and I prefer
in such cases to heat my ovens by pipes running crossways to the direction in which
the baking plates travel. My oven apart from its system of heating by steam
pipes then resembles the well known travelling "chain" or "plate" biscuit ovens
with however this difference that in my oven the bread is all set as quickly as
possible with the end of the oven hermetically closed and run entire into the oven
in the shortest possible time. The feeding end being only opened for a moment
to run the plate in and out is now also closed hermetically and the batch is left
quietly in the oven until it is perfectly baked. When baked it can be drawn out
at either end one end however only requiring to be opened for the purpose during
.a very short period of time only. I sometimes, where the commencement gools

page_text: want a very different baking temperature from that which they require later on,
connect two or more oven chambers and have separating doors or sluices or other
contrivances by means of which the total or whole baking chamber can be
subdivided and the difference of temperature in the different chambers can be kept
up and put my rails right through these various oven chambers and pass the
goods to baked or dried on their travelling baking plates through these chambers
in the required rotation and where the oven chambers cannot be constructed so that
one forms the continuation of the other but where for some reasons they are to be
one above the other I run either my drawplate right out of the baking chamber
and lift it up or lower it down to the level of the other chamber in order to push it
into that or I provide mechanical means for lifting up or lowering down my baking
plate inside the respective chambers from oue to the other in which case I am
obliged to construct the horizontal partitions between the baking chambers in a
movable way in the manner of a slide or damper which I draw while the baking
plate is raised or lowered and which I put in again after the operation is
performed.
T
GEO. DOWNING,
8, Quality Court, London, W.C., Agent for Applicant.
Improvements in Drawplate Ovens, more particularly of the
"Wieghorst" System.
I, PAUL PFLEIDERER, of the firm of Werner & Pfleiderer, of 86 Upper
Ground Street, London, S.E., and of Cannstatt in Germany, Bakery Engineer
do hereby declare the nature of my said invention and in what manner the same
is to be performed, to be particularly described and ascertained in and by the
following statement:-
"
This invention consists of improvements in draw-plate ovens, and relates more
particularly, (but not exclusively) to ovens constructed upon the "Weighorst'
system, No. 4215, and my improvements thereon No. 19,506 and No. 10,019".
And in order that my said invention may be particularly described and ascertained,
reference is hereby made to the accompanying drawings, in which similar letters of
reference indicate corresponding parts.
Fig. 1 is a longitudinal sectional elevation of an oven heated on the Wieghorst
system, illustrating one method of mounting and manipulating the draw plates;
and Fig. 14 is a horizontal section of the same.
Fig. 2 is a longitudinal sectional elevation, illustrating another method of
mounting and manipulating the draw plates; and Fig. 2ª is a horizontal section
of the same.
Figs. 3, 4, 44, 5 and 54, are detail views, sections and modifications relating to
the invention.
Fig. 6 is a perspective view of an oven, illustrating methods of withdrawing and
manipulating the draw plates or trays.
Fig. 7 is a longitudinal sectional elevation, illustrating other improvements in
the construction and manipulation of the ovens.
Fig. 8 is a horizontal section of the same.
Fig. 9 is an end elevation, and
Fig. 10 a detail view.

page_text: Referring to Figs. 1 and 1ª : R. R are two. rails extending the whole length of
the oven and beyond the front, as shown; the outer ends being supported upon
uprights C, C, when drawn out. The rails K. R may be drawn out, as shown by
dotted lines at R', in Fig. 1 in order to sustain the draw-plate P, when so drawn
out. The draw-plate rests on the rail R. R when in the oven, as shown by solid
lines in Fig. 1. The draw-plate P is fitted with wheels w running in grooves on
the rails R, or formed with flanges to prevent derailment.
In Figs. 2 and 24 stationary wheels D. D are shown mounted upon supports C
and C, upon which inverted. rails attached to the draw plate P¹ run weights W
being fitted to the draw plates to prevent overbalancing, when drawn out, as shown
by dotted lines.
In these figures S. S. are the Wieghorst tubes; B is the oven; F. is the
furnace, and K K are openings for inspection and feeding.
In order to economise space in front of the oven, I sometimes hinge the rails so
as to fold over either vertically, as shown in Fig. 3, or horizontally, as shown in
Figs. 4 and 4 at R" and R. The rails may also be made in several lengths, so
as to be capable of sliding telescopically, one into another. The travelling draw
plates P may also be fitted with bearing bars r r, as shown in Figs. 13, 13ª, 138
and 14; in which figures the wheels w are shown mounted on a loose frame; the
bars rr merely resting on the axles of the wheels w and rolling thereupon. By
these and analogous devices, facilities are afforded for removing and in some cases
dispensing with the supports C. C.
I sometimes construct the draw-plates P and P¹ with raised sides u u, fitted with
hinges hh, as shown in Fig. 6; in which figure a steam oven is shown with an
opening B at one end, as in all ordinary daily bread baking ovens fired at the back
or opposite end to the opening B. The heating pipes run parallel with the
rails r. T.
Transverse ovens are also shown at BB' in Fig. 6, fitted with
corresponding rails R'. Openings for obtaining access to the furnace are provided
at L fitted with movable doors.
In ovens having heating or steam pipes S¹ running transversely to the rails, as
shown in Figs. 11 and 11^; (being the form usually adopted when built against a
wall, parallel to the pipes) the pipes farthest from the opening are somewhat
inaccessible, and therefore difficult to handle. To overcome this difficulty I fit the
pipes S₁ with clips E. E, preferably in pairs, as shown in Figs. 5, 5ª, 11, 11ª, 12
and 12. Transverse axles are fitted having fingers or cranks z fast thereon,
which engage the clips E in such a manner that, by raising or lowering an arm 1,
attached to the axle x, the pipes S¹ can be pushed farther into the furnace For
withdrawn therefrom, to regulate the required temperature. y y are additional
supports to these axles.
For the same purpose I sometimes provide openings, as shown in Figs. 7, 8, and 9,
fitted with doors K. K, and loose fire bricks b. b, whereby access may be obtained
to the pipes for purposes of adjustment, without breaking or cutting the wall.
In order to render the walls secure, where the heat of the furnace is greatest, I
insert therein tie-bars or bolts T, firmly attached by screws or otherwise to wall
plates t, as shown in Figs. 7, 8, 9 and 10. Two, three, or more wall plates are
used, as required, as shewn in Fig. 9, which wall plates also serve as solid metallic
supports to the angled ends of screw bolts vv, as shown in Fig. 10 for securing the
door frames f, and other necessary fittings; for which purpose screws with plain
shanks have usually been built into the wall and held by friction derived from
contact with masonry.
The doors and passages leading to the furnaces may be used for lighting the gas,
inspecting the fires, adjusting and cleaning the tubes and flues, and removing soot
and ashes.
When large furnaces are used, I provide horizontal steadying piers or stays G.
(Figs. 11 and 11) in the firebrick furnace flue, and tie the walls with tie
bolts T¹.
I also sometimes build my ovens in two or more superposed tiers or "decks,” and

page_text: nearly at right angles to each other, wherever the premises are suitable, as shown
in Fig. 6, which represents a two decked oven, with three ovens, two below and
one above.
"
Where the premises are suitable, I prefer to run my baking plates into the oven
at one end, and out of it at the other end, and in such cases I also prefer to heat
the ovens by pipes running transversely to the direction in which the baking plates
travel. In this arrangement the oven (apart from the system of heating by steam
pipes) resembles the well-known "travelling chain" or "plate biscuit ovens ;
with, however, this essential difference, that in my oven the bread is all set as
quickly as possible, with one end or oven-mouth hermetically closed, and the draw-
plate is run into the oven in the shortest possible time, the feeding end being
opened only to run the plate in and out, is then also closed hermetically, and the
batch (like that in any ordinary bread oven) is left quietly to itself until perfectly
baked. When baked, it may be drawn out at either end, the other end remaining
closed.
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. The combination with draw-plate ovens of the description aforesaid, of rails
for supporting the draw-plates or baking-plates, constructed so as to telescope or
fold out of the way, while the draw plates are in the oven, substantially as and for
the purpose herein before described and illustrated by the drawings.
2. The combination with draw-plate ovens as aforesaid, of draw-plates fitted with
inverted rails, and supported by stationary wheels or rollers, so as to obviate the
necessity for fixed rails, substantially as herein before described and illustrated by
the drawings.
3. The combination with draw-plate ovens as aforesaid, of draw-plates fitted with
movable or hinged sides or flaps, substantially as herein before described and
illustrated by the drawings.
4. The combination with draw-plate ovens as aforesaid, of superposed ovens
in two or more tiers or decks, beated by one furnace; the draw-plates being
worked from opposite ends or at right angles to each other, substantially as and
for the purposes herein before described and illustrated by the drawings.
5. The combination with draw-plate ovens as aforesaid, of clips bolted to the
pipes, and levers for manipulating the same, substantially as herein before described
and illustrated by the drawings.
6. The combination with draw-plate ovens as aforesaid, of tie bolts, and wall
plates for securing the walls and supporting the fire doors and other fittings,
substantially as herein before described and illustrated by the drawings.
7. The combination with draw-plate ovens as aforesaid, of openings fitted with
doors for the purpose of inspecting the furnace and regulating the pipes, and for
other purposes, substantially as herein before described and illustrated by the
drawings.
8. The combination with draw-plate ovens as aforesaid, of hermetically fitting
doors at each end of double-ended ovens substantially as herein before described
and illustrated by the drawings.
9. The general construction, and the several and respective arrangements and
combinations of parts, together constituting my invention of improvements in draw-
plate ovens, more particularly of the "Wieghorst" system substantially as herein
before described and illustrated by the drawings.
Dated 26th May, 1000