Improvements in Electric Water Heaters.
Year: 1892

page_text: COMPLETE SPECIFICATION.
Improvements in Electric Water Heaters.
I, THOMAS AHEARN, of 70 Sparks Street, in the City of Ottawa, in the County
of Carleton, in the Province of Ontario, in the Dominion of Canada, Electrician,
do hereby declare the nature of my invention for "IMPROVEMENTS IN ELECTRIC
WATER HEATERS," and in what manner the same is to be performed, to be
particularly described and ascertained in and by the following statement:-
My invention, which will be hereinafter fully set forth and claimed, relates to
devices for heating water by means of an electric current.
Figure 1 is an elevation of my improved water-heater.
Fig. 2 is a vertical section of the same on line x .c, Fig. 1.
Fig. 3 is a horizontal section on line y y, Figs. 1 and 2.
A is an open vessel, preferably metallic and a good conductor of heat-such as
copper, tin, or thin cast-iron-adapted to hold water. Upon this are placed strips
of insulating material B, such as asbestos. Upon this insulation is wound a coil of
wire
or strip C of refractory material having a high electric resistance--such as
German silver-and the terminals connected with leads cc' of an electric circuit.
The vessel thus insulated, coiled, and connected is placed in a larger vessel or
container D, large enough to leave an annular space all round the inner vessel A
and also a space between the two bottoms. The latter space is packed with a good
non-conductor of heat and electricity E-such as asbestos- and the annular space
is filled with powdered whiting, fire-clay, or other refractory material F, which is
also a non-conductor of electricity. The interior of the vessel D is also lined with
asbestos or other non-conductor of heat E'. The top of the annular space is made
up with a ring cover G, provided with insulators g g, through which the leads cc',
are passed. The inner vessel A is provided with a removable hollow cover H, the
interior of which is packed with a good non-conductor of heat, such as asbestos h.
An opening is provided in said cover convenient for filling the vessel.
To the interior of the cover H may be attached a closed water-tight vessel H¹ of
such a size as to reduce the water-space in the vessel A and form an annular
space around said vessel H¹ and a space between its bottom and that of the
vessel A.
I is the draw-off pipe, preferably secured in the bottom of the vessel A and
passing through the bottom of the container D and provided with a suitable
faucet i. To said pipe I may be attached a branch I', provided with an elbow and
socket ¹, in which a gage-glass 1" is secured. The outer vessel or container D
may be further packed externally with a non-conductor of heat and suitably lagged
with wood or other material, if desired.
The vessel A is filled with water, the level of which may be readily observed in
the gage-glass I". A switch being provided in the leads c c at a suitable point,
the current may be turned on or off when desired. The coil C is of such a
sectional area that it is heated by the passage of a current without being fused.
The heat thus created in the coil is conducted by the filling F to the vessel A and
by it communicated to the water in said vessel. The water-level in the vessel A
may be maintained uniformly by any well-known automatic regulating device
suitably connected with said vessel.
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. In an electric water-heater, the combination of an insulated open water-tight
vessel A. a coil of refractory wire or strip C, of low electric conductivity, having

page_text: its terminals connected by leads passing through insulators, a containing-vessel D,
lined internally with a layer of non-heat-conducting material and large enough to
form an annular space around said inner vessel and affording space for a thick
layer of non-conducting material at the bottom, a covering G on the annular space
containing insulators to pass the leads of the circuit, a removable hollow cover H,
a draw-off pipe I, with faucet, and a filling of powdered whiting, fire-clay, or other
refractory material in the space between the inner and outer vessel and in the
cover, substantially as set forth.
2. In an electric water-heater, the combination of an open water-tight vessel A,
insulating-strips B, laid upon the exterior of said vessel, a coil C, wound upon said
insulating-strips and connected with a circuit, a hollow cover H, filled with non-
conductors of heat and provided with an opening ', a water-tight vessel H',
connected to the bottom of said cover and smaller than the vessel A, a draw-off
pipe I, secured in the bottom of the vessel A and provided with faucet, a branch I¹
on said pipe, and a gage-glass I", secured to said branch, substantially as set
forth.
Dated this 16th day of September A.D. 1892.
THOMAS AHEARN,
Per A. Harvey,
His Attorney.