Improvements in Thermo-electric Generators.
Year: 1896

page_text: Date of Application, 9th June, 1896-Accepted, 11th July, 1896
COMPLETE SPECIFICATION.
Improvements in Thermo-electric Generators.
We, HARRY BARRINGER COX, of The Cox Laboratory, St. Albans, in the County
of Herts, Electrician, and THE COX THERMO-ELECTRIC COMPANY, LIMITED,
of 14 Old Jewry Chambers, in the City of London, 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:-
This invention has for object to provide an improved thermo-electric generator
wherein the active current generating element per se, is easily removable from the
supporting or enclosing parts and framework so that the active part can be easily
removed and replaced at a minimum cost without in any way injuring or disturbing
the said supporting or enclosing parts and framework. A further object of the
invention is to provide certain improvements in details of construction and
arrangements of parts whereby a highly efficient and practically and economical
successful thermo-electric generator can be constructed and maintained at a
minimum cost.
A thermo-electric generator is, for these purposes, constructed as we shall now
describe referring to the accompanying drawings wherein,
Figure 1 is a vertical section showing the casing and supporting parts of a
thermo-electric generator according to this invention, the active element of the
generator being removed.
Figure 2, is a similar view showing the thermo-electric generator complete with
an active element clamped in place therein.
Figure 3 is an elevation showing the active element removed from its casing and
such as is shown in section and secured within the casing in Figure 2.
a is a supporting bracket adapted to be secured to the side of a vertical support
and provided at its outer end with radiating and upwardly extending arms b. At
the centre from which these arms radiate, the bracket has a central vertical
opening and clamping screw c, to receive and hold a gas supply pipe d with
burner d', which may be of any desirable construction. Although we have thus
specifically described a satisfactory form of supporting device for the parts
hereinafter set forth, yet we do not limit ourselves to any particular form of
support as any suitable and desirable support can be employed.
e is an annular plate forming the bottom of a supporting casing for the active
element of the thermo-electric generator. It rests on and is securely bolted to the
upwardly extending ends of the radiating arms of the bracket, and is provided
around its open centre with an upwardly extending annular flange f g is a
cylindrical casing that forms the outer wall of a water jacket and extends
upwardly from the outer edge of the plate e to which it is tightly secured
so as to form a water tight joint or with which it can be formed in one piece, if
desired.
h is an annular top plate tightly secured to or formed in one piece with the
upper part of the casing g, the diameter of the central opening in this plate being
greater than that in the bottom annular plate e. i, is a gasket or ring of packing
material such as india rubber or other suitable material resting on the upper
surface of the annular bottom plate e and surrounding the central flange f thereof.
j is a similar gasket or packing ring that rests on the upper surface of the annular
top plate and projects slightly over the active element within the casing g. k is
the removable thermo-pile or active element of the thermo-electric generator. It
is made in the shape of a cylinder built up of rings of thermo-couples, the rings

page_text: being arranged one above the other with insulating material between them and all
the rings being properly electrically connected as well understood. I and m are
flexible terminal wires leading from the opposite poles of the element located
respectively in the bottom and top rings of thermo-couples, the top conductor in
being brought down through the generator between the opposite poles of each ring
and insulated therefrom so that both conductors extend out through the bottom of
the generator.
In constructing such a thermo-pile or active element, after the rings have been
properly arranged and connected, the entire cylinder is coated and filled in between
the elements and rings with suitable plastic refractory material such as fire-clay
cement or the like, that can be hardened so as to form a hard rigid cylinder as
well understood and through one end of which the terminal wires m pass to the
exterior of the cylinder.
A covering n of sheet metal is placed around the cylinder and intimately united
therewith or secured thereto its ends o being arranged to project slightly beyond
the ends of the cylinder, and, if desired, slightly turned, beaded or rounded, though
this is not essential.
The thermo-pile or active element thus constructed is complete in itself. It is
placed in the casing g with the lower end thereof resting on the flange of the
annular bottom plate e the opening in which it overlaps, the lower projecting end o
of the metal covering n pressing into the lower ring i so as to force the same against
the said flange and the annular bottom plate, and thereby form a water tight joint
at this part. The upper end of the active element fits within the annular top plate h
of the casing g aud upon its upper projecting end o the packing ring jis placed.
P is a clamping ring arranged to rest on the packing ring j so as to extend partially
over the top plate h and the upper end of the active element. 79 are removable
screws arranged to pass through the packing ring j and into the top plate h, the
arrangement being such that upon tightening up the said screws, the packing ring j
will be compressed between the clamping ring p, the top plate h and the upper
projecting end o of the metal covering n, thereby forming a water tight joint
between the active element and top plate of the casing g whilst at the same time
securely holding the said active element in place.
r is a light spider frame having vertical sockets in the ends of its arms so that
it can be removably fitted on vertical guide pins s on the plate h. This spider
frame carries a depending rod t that extends centrally down into the hollow centre
of the active clement and carries a series of annular deflectors t', that are of
gradually decreasing size in a downward direction. This spider is placed in
position after the active element has been properly set and secured by the clamping
ring p, and can be easily lifted from its position and laid on one side when the
active element is to be removed. On the upper side of the supporting bracket a
are secured two binding screws u, (one only of which can be seen in the drawings)
which are insulated from each other and from the bracket and to which are
secured the two conductors l m that pass from the bottom of the active element
out through the open bottom of the casing g, and also the wires constituting the
working lines.
When it is desired to remove the active element, for any reason, from the
casing g, the spider frame r, with the deflectors t', is lifted from the casing and
the active element therein, the screws q are removed from the top plate h, the
clamping ring p and packing ring ; are removed, and the terminal wires l, m,
loosened from the binding screws u, whereupon the active element can be lifted
bodily from the casing g, out through the open top thereof with the terminal
wires m hanging loosely therefrom.
It will be readily understood that the outer metal wall n of the active element
and the casing g form with the top and bottom plates h and e respectively, an
annular chamber adapted to contain the water intended to serve as the water
jacket around the active element, the casing being provided with suitably arranged
pipes v, for the inlet and outlet respectively of water.

page_text: The heat from the gas burner d¹ passes centrally up through the open centre of
the active element and is equally diffused and distributed throughout the inner
surface thereof by the deflectors t' as will be clearly understood without further
description, while the outer surface of the active element will be maintained at a
practically even and lower temperature throughout and the heat rapidly diffused,
by the water circulating through the water-jacket in order to produce the necessary
fall in thermic potential within the active element.
In the practical construction and maintenance of thermo-electric generators, it is
desirable that the active element should be removable and renewable so that it will
not be necessary to injure the casing, which is comparatively expensive, every time
the said element needs repairs or renewal. The active element is a comparatively
inexpensive device and the only part that ever needs renewing within the life of the
casing. Hence the importance and utility of this invention will be appreciated, as
the active element can be made to standard sizes and supplied separately and kept
on hand by the user, and it will not be necessary to injure the generator, as
heretofore, in order to remove the active element, and which had the effect of
shortening the life of the entire machine to that of the life of its particular active
element, whereas according to the present invention one casing will last indefinitely
and the active element can be renewed as desired. By this means the practical
and commercial success of thermo-electric generators is greatly enhanced and their
utility established.
It is evident that various changes might be made in the forms, arrangements and
construction of the parts described, without departing from the spirit and scope of
our invention, hence we do not wish to limit ourselves to the exact construction
herein set forth, but consider ourselves entitled to such changes as fall within the
spirit and scope of the invention.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed we declare that what
we claim is :-
1. As an article of manufacture, an active generating element for a thermo-
electric generator complete in itself with a hard rigid coating having an electric
terminal wire extending down through the coating so that both terminal wires pass
from the same end of the element, substantially as described.
2. A thermo-electric generator comprising a supporting casing forming a water
jacket, and the removable active element forming the inner wall of the water
space and removable from the casing without disturbing the same, substantially as
shewn and described.
3. The active generating element, as an article of manufacture, comprising the
hard cylinder of refractory material enclosing the properly connected thermo-
couples and having around it a metal jacket the two ends of which project beyond
the end of the said cylinder, and the terminal wires extending through the same
part of the refractory material substantially as shewn and described.
4. A thermo-electric generator having a supporting casing with a top opening
to permit insertion or removal of the active generating element, and the removable
active element arranged in said casing and forming a tight joint therewith so
that the casing, can contain water to surround the said element, substantially as
described.
5. The improved thermo-electric generator constructed substantially as described
and shown for the purposes set forth.
Dated this 9th day of Inne 1896