Improvements in Doors or "Stocks" and Fittings of Baking Ovens.
Year: 1891

page_text: Date of Application, 12th June, 1891
Complete Specification Left, 12th Apr., 1892-Accepted, 12th Sept., 1892
PROVISIONAL SPECIFICATION.
Improvements in Doors or "Stocks" and Fittings of Baking Ovens.
I, PAUL PFLEIDERER, of the firm of Werner & Pfleiderer of 86 Upper
Ground Street London S.E. Bakery Chemical Consulting and Mechanical Engineer
do hereby declare the nature of my said invention to be as follows:-
In order to offer greater facilities for opening, closing, as well as keeping more
perfectly steam tight, the mouths or doors of bakers' ovens I make the doors sliding
and to fit exactly the planed or tooled faces of the oven mouths to which they
belong and which faces I give more or less incline.
I make these sliding doors in one piece or in two parts so connected with counter-
weights or with each other that by moving the one part in one direction the
counterweight or other part moves in an opposite direction.
By making the sliding door in two parts so that the one forms the counterweight
of the other I gain the further advantage that for every inch the attendant opens
or closes one part the corresponding increase or decrease of the opening will be
two or more inches by the other part moving or receding in an opposite sense.
I interpose a countershaft with chain wheel or wheels over which pass chains
whose ends are fixed on the one side to the one and on the other to the other
part of the oven door or to the counterweight; or instead of these chainwheels
and chains I employ spurwheels or pinions and rigid toothed racks so that when
one part of the door is moved the rack or racks fixed to it cause the pinion or
pinions, and thereby the countershaft, to revolve, and this revolving countershaft
through the same or separate pinions gearing into racks fixed to the counterweight
or other part of the oven-door causes the latter to move in an opposite direction.
In the arrangements in which the two parts of the ovendoor are moved asunder
in a vertical direction I prefer the chain arrangement and I proportion the weights
of the two parts so that they act as the balancing or counterweights for each other,
while I prefer the rack & pinion arrangement where the two parts move asunder in
a horizontal direction.
But a similar effect can be produced by interposing a system of levers or links
between the two parts of which my oven doors consist.
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When I employ a sliding door in one piece similar to those hitherto used in
Wieghorst ovens I prefer one instead of two counterweights; this I suspend
from the one ends of chains the other ends of which are fixed to the ovendoor and
which chains pass over chain wheels mounted on the interposed or countershaft by
revolving which the opening & closing movement is performed.
This countershaft I revolve by hand by suitable handwheels of larger diameters
than those of the chain wheels and as the two parts of the door or the door and its
counterweight balance each other the small amount of friction or sticking of the
door is very easily overcome. I also prefer to place the counterweight out of
sight and out of reach, so as to avoid all possibility of tampering with it
and to entirely remove all danger of dropping it on the feet of any attendant or
bystander.
This I perform by so constructing the mouthpiece or stock frame of the oven
that the chains are protected and like the weight work or move in recesses left in
the casting and the front wall of the oven or in both.
I further prefer the slightly inclined face of the ovenmouth and fix the counter-
shaft so that the door is kept or pressed against the mouth by its own weight
hanging on the chain. When the door is let down to close the mouth, it settles
into wedgelike brackets which tend to hold it up tight against the ovenmouth at

page_text: the bottom, while by a simple manipulation a lever which with broad oven mouths
is a double crank lever is pulled or dropped down to press the top of the door
tight up against the face or mouth of the ovenfront or stock.
These doors & stocks, or ovenfronts I further construct with suitable cores &
recesses, and fill them with non-conducting material and put lagging over the same,
so that they take up a minimum of space and allow less heat to escape or radiate
from the oven than is generally the case with the usual ovendoors whether they are
fitted flush with front brick wall or standing back to come nearly flush with inside
of ovenfront.
Dated 10th 1001
PAUL PFLEIDERER.
COMPLETE SPECIFICATION.
Improvements in Doors or "Stocks" and Fittings of Baking Ovens.
I, PAUL PFLEIDERER of the firm of Werner & Pfleiderer of 86 Upper Ground
Street London S.E. Bakery Chemical Consulting and Mechanical Engineer, do
hereby declare the nature of said invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement
In order to offer greater facilities for opening closing as well as keeping more
perfectly steamtight, the mouths or doors of bakers ovens, I make the doors sliding
and to fit exactly the planed or tooled faces of the oven mouths to which they
belong and which faces I give more or less incline.
On the accompanying Sheets I and II of drawing Figs. 1 to 9 show in what
manner I obtain this object. Like letters of reference in all figs. referring to like
parts.
I make these sliding doors in one piece D or in two parts d d¹ so connected with
counterweights D¹ or with each other that by moving the one part D or d in
one direction the counterweights D¹ or the other part d' moves in an opposite
direction.
By making the sliding door in two parts d and d' so that the one forms the
counterweight of the other-I gain the further advantage that for every inch the
attendant opens or closes one part the corresponding increase or decrease of
the opening will be two or more inches which result is caused by the other part
moving or receding in an opposite sense.
I interpose a countershaft s with chain wheel or wheels w over which pass
chains c whose ends are fixed on the one side to oven door D or the one part d of
same and on the other side to counterweight D' or the other part d' of the oven
door or instead of these chain wheels and chains I employ spur wheels or pinions P
and rigid toothed racks R so that when one part d of the door is moved the rack
or racks R fixed or hinged to it cause a pinion or pinions P and thereby the
countershafts to revolve and this revolving countershafts through the same or
separate pinions P gearing into racks R fixed to the counterweights D' or other
part of oven door d' causes the latter to move in an opposite direction of that in
which the entire door D or the part d of it is moved.
In the arrangements in which the parts d and d¹ of the oven door are moved
asunder in a vertical direction I prefer the chain arrangement illustrated on
Sheet II Figs. 4, 5, 7, 8 and 9 and I proportion the weights of the two parts so
that they act as balancing or counterweights to each other, while I prefer the
"rack and pinion" arrangement Sheet II Fig. 6 where the two parts move asunder
in a horizontal or inclined direction.
When I employ a sliding door D in one piece similar to those, hitherto used in
Wieghorst ovens, as illustrated on Sheet I Figs. 1. 2 and 3-1 prefer one single
counterweight D¹ to two smaller counterweights and I suspend D' from the one end
of chains c the other ends of which are fixed to the two trunnions of oven door D

page_text: and which chains pass over chain wheels W mounted on the interposed or counter-
shafts by revolving which the opening and closing movement is performed.
I also
This countershaft I revolve by hand by suitable handwheels H of larger
diameters than those of the chain wheels W. and as the two parts d and d¹ of
the door or the entire door D and its counterweight D' balance each other the
small amount of friction or sticking of the door is very easily overcome.
prefer to place the counterweight out of sight and out of reach so as to avoid all
possibility of tampering with it and to entirely remove all danger of dropping it on
the feet of any attendant or bystander.
For this purpose I construct the mouthpiece or stock frame of the oven in such
a manner that the chains c and weight D' are protected and work or move in
recesses and O' Sheet I Figs. 1. 2 & 3 with which recesses or channels the
castings of oven mouths and the front wall respectively are provided.
I generally prefer the slightly inclined face of the oven mouth and fix the
countershaft so that the door is kept or pressed against the mouth by its own
weight.
To secure a still more reliable steamtight joint I provide wedge like brackets b
Sheet I Figs. I and 2 into which the door settles which brackets tend to hold it
up tight against the oven mouth at the bottom while by a simple manipulation
a lever which in broad oven mouths is a double crank or loop lever L Sheet I
Figs. 1 and 2 is pulled or dropped down to press the top of the door tight up
against the face or mouth of the oven front or stock. These doors or stocks
or oven mouths I further construct with suitable cores or recesses N and fill
them with non conducting material and put lagging over the same so that they
take up a minimum of space and allow less heat to escape or radiate from the
oven than is generally the case with the usual oven doors, whether they are such as
are usually fitted flush with front brick wall or standing back to come nearly flush
with the inside of oven front.
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 1
claim is :-
In bakers ovens.
1. The mode of counterbalancing the sliding door either by one counterweight D¹
or by the two parts d and d' of the door balancing each other.
2. The mode of moving the door D or parts d and d for opening and closing the
oven mouth by means of one or two hand wheels H fixed on countershaft s.
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3. The mode of pressing the doors up against the oven mouth by means of
'wedge and lever "arrangement b and L.
4. The mode of recessing the casting of oven mouth and front wall of oven to
protect or hide the chains and counterweight.
Dated 12th April 1892.
GEO.
DOWNING,
8, Quality Court, London, W.C., Agent.