Improvements in Electrical Heating Apparatus.
Year: 1891

page_text: Date of Application, 23rd Dec., 1891-Accepted, 23rd Jan., 1892
COMPLETE SPECIFICATION.
Improvements in Electrical Heating Apparatus.
I, CARL DREVS of Gorm near Oertzenhof, (Mecklenburg-Strelitz) in the
German Empire, Farmer, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
The leading idea of this invention is that if an electrical current is sent through
a number of resistances in a vessel or cell of insulating material and the ambient
air is allowed constantly to pass through such vessel or cell, the heat generated in
the resistances will be imparted to the air.
In the accompanying drawings;-
Fig. 1 is a vertical section, and Fig. 2 an elevation of the electrical stove, the
two remaining Figures 3 and 34 being detail views.
Upon a base or pedestal C (Fig. 1) are arranged two cylinders A and B of
insulating material forming between them an annular and cylindrical space closed
at the top by an annular arch. Spiral grooves a and b are provided in the internal
wall of the outer cylinder and in the external wall of the inner cylinder respectively
for the reception of the resistances e, Figs. 3 and 34. The resistances consist of
small elongated pieces of metal tapering on both sides in the direction of the
current so that the current is compelled to pass on from one of these metal pieces
to the other producing a spark during the passage. For securing these small metal
plates in position a dove-tailed recess as shown in Fig. 34 is formed in the stove-
wall behind each of the grooves a and b, the widened portions of which are directed
inwardly. With each of these recesses are adapted to engage double springs c, the
two ends of each of which press upon the opposite walls of the recess (Figs. 3
and 34). In each of these springs at the part remaining outside of the recess, is
fitted by means of a stud d one of the metal plates or resistances e.
This
description of resistances is however given only by way of example as any other
suitable form of resistance may be employed.
h
Around the base and in its crown or top-plate are provided openings y
respectively through which the external air is admitted while in the annular arch
or dome surmounting the stove, similar openings are provided for the escape of
such air.
In constructing and fitting up the various parts of this stove no mortar or similar
binding medium should be employed the parts being joined as shown in Fig. 1, by
means of grooves and tongues a frame D maintaining the whole.
When it is desired to heat an apartment an electrical current is conveyed into
the resistances e entering at m and passing through each of the resistances in
succession until it arrives at n whence it returns to its source. During such
passage of the current heat is generated in the cylindrical chamber with the result
that the cooler external air is sucked in through the inlets g h heated within the
aunular chamber and allowed to pass out at 1 to heat the rooms.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed I declare that what I
claim is :-
1. In an electrical stove or heating apparatus two concentric cylinders such as A
and B of fire-proof and insulating material provided on their adjacent interior faces
with spiral grooves such as a and b adapted to receive one or more conductors
capable of opposing a powerful resistance to the electrical current passing through
them air being conducted through the stove in a vertical direction and in such a

page_text: manner that in passing it comes into contact with the incandescent wire con-
volutions substantially as described and illustrated in the accompanying drawings.
2. In a heating apparatus or stove such as described the employment of a hollow
inner cylinder such as B3 for the purpose of producing a more effective transmission
of heat and a better flow of the air substantially as described and illustrated in the
accompanying drawings.
3. In a heating apparatus such as described the employment of resistances such
ase in the shape of small elongated metal plates tapering or pointed at both ends
in the direction of the current whereby the current is directed from one plate to
the other producing an arc at each successive break substantially as described and
illustrated in the accompanying drawings.
Dated this 23rd day of December 1891.
W. P. THOMPSON & BOULT,
Agents for the Applicant.