Year: 1886

page_text: ALFRED JULIUS BOULT of 323 High Holborn, in the County of Middlesex,
Engineer, do hereby declare the nature of this invention (a communication from
Julien Bolvin of Paris, in the Republic of France) and in what manner the same
is to be performed; to be particularly. described and ascertained in and by the
following statement:-
The ordinary openings or mouths of bakers ovens of the "viennese" description
are provided with or closed by flat vertical doors which are balanced by means of
counterweights. These doors present numerous defects and in consequence of
their vertical arrangement do not fit tight to the mouth of the oven and so let a
considerable quantity of heat and steam escape.
The object of this invention is to remedy these defects and I therefor place this
oven door at an inclination instead of vertically so that it is always obliged to rest
upon the correspondingly inclined edge of the oven mouth.
The invention also includes improved means of counterbalancing the weight of
the door and improvements in the lighting apparatus which latter has heretofore
consisted of a pane of glass or mica simply placed in the casting without any
adjusting while this system consists of an entirely independent box properly
closed in front and at the back and sufficiently air-tight to enable the gas to burn
even during the baking of the bread, while in the older systems the gas was often
extinguished by the escaping steam.
In the accompanying drawings:
Figure 1 represents a front view of this improved oven door.
Figure 2 is a sectional side elevation of the same on the line A B of Figure 1.
Figure 3 is a sectional side elevation of the same on the line C D of Figure 1.
Figures 4, 5, 6, 7, 8 and 9 shew modifications of the apparatus for moving and
counterbalancing the door.
H is a toothed segment engaging with a pinion fixed on the shaft J which
carries two other pinions G engaging with the two racks F attached to the oven
.

page_text: door E. The racks F serve in this manner to raise or lower the oven door.
I is a counterweight to balance the weight of the oven door which moves in
guides.
K is the box, carrying the mica pane L, and it fits tight into the casing O at the
points M and N. A vertically sliding door P serves to shut the box K and a
handle provided with a pawl engaging in a ratchet on the oven serves to hold
the door P at the required height. A small horizontally sliding door R is arranged
on the door P to open or shut the apertures S and T.
Figure 4 represents a modification for the opening or shutting of the door. The
lever U here raises or lowers the oven door through the medium of the arm V
which is attached to the lever U and the oven door by ball joints or other means
permitting movement in any direction.
In Figure 5 the toothed. segment X engages direct with the rack on the oven
door and is balanced by a counterweight over a pulley or otherwise.
In Figure 6 the toothed segment Y serves also as counterweight and turns the
shaft Z by means of a pinion fixed thereon. The shaft Z raises or lowers the oven
door by racks and pinions as in Figure 1..
In Figure 7 the oven door is operated by a lever A' and the counterweight B¹
suspended on a chain which runs over two pulleys. If desired the lever A' may
be omitted.
In Figures 8 and 9, Figure 9'being a section on line K' L' of Figure 8, the two
chains C and D are fixed to the bottom of the oven door and with their upper
ends to a roller or cylinder fixed on the shaft E¹. A third chain G¹ is fixed with
its lower end to the counterweight H¹ moving in convenient guides and provided
with friction rollers if desired, while its upper end is fixed to a third roller F¹.
will be seen by the drawings the chains CD₁ are wound round their rollers in the
opposite direction to the third chain G¹ so that while the one is wound up the
other are wound off and thus the counterbalance is obtained. .
As
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, as communicated to
me by my foreign correspondent I declare that what I claim is,
1. In a bakers oven an inclined door either plane or curved in place of the
ordinary vertical door substantially as specified.
2. The independent lighting box K closed at one end by the mica pane L and at
the other by a door P adjustable by means of a pawl Q substantially as herein
specified and illustrated by Figure 3 of the accompanying drawings.
3. The methods of and apparatus for opening and balancing the oven door
substantially as herein specified and represented in the accompanying drawings.
Dated this 21st day of June 1886.