Improvements in Electric Transformers or Converters.
Year: 1895

page_text: Date of Application, 26th Feb., 1895--Accepted, 6th Apr., 1895
[Communicated from abroad by THOMSON ELECTRIC WELDING COMPANY,
of Lynn, Massachusetts, United States of America.]
Improvements in Electric Transformers or Converters.
1, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, 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 :-
My invention relates to transformers or converters and is designed especially to
provide an efficient and cheap construction of a transformer adapted to furnish the
heavy currents employed in electric welding and other metal working apparatus.
While I have described the invention as carried out in a transformer having its
coils or conductor of heavy cross section forming the secondary thereof, it will be
obvious to electricians that the transformer constructed as hereinafter described
might be employed for generating currents of higher potential than those supplied
to it by simply using the conductor of heavy cross section as a primary and,
therefore, my claims are to be understood as covering that use of the construction
specified in such claims which would involve simply the inversion of the apparatus,
that part of the same which is for ordinary use the secondary becoming in such case
the primary. I shall, however, describe the invention as carried out in a transformer
wherein the conductor or coil of heavy cross section is used as a secondary to
generate heavy currents.
My invention provides a transformer wherein magnetic leakage between the
primary and secondary will be prevented; the primary will be prevented from
contact with the secondary in an effective manner while the primary will be rendered
waterproof and shielded from mechanical injury as well; and the heat generated
either in the primary or secondary during use will be readily carried away without
breaking down the insulation.
The invention consists in making the secondary or heavy section element of the
apparatus as a liquid tight tube which envelops the primary and in keeping the
primary immersed in oil contained in said secondary.
The invention cousists further of an electric transformer having a primary wound
with a number of turns and a secondary having but one turn and composed of a
single tube which follows the winding of the primary coil and forms a tubular
envelope or jacket therefor throughout substantially its whole length.
The invention consists further in making the secondary or heavy section element
from two solid copper castings bolted together to form a tube enclosing the
primary.
The invention consists also in the features of construction and combinations more
particularly specified in the claims
In the accompanying drawings:-
-
Fig. 1, illustrates a transformer embodying my invention the usual iron core
being removed.
Fig. 2, is a vertical cross section through said transformer on the line a, a,
Fig. 3.
Fig. 3, is a vertical section of the transformer taken on the line y, y, of Fig. 2.
A, is the tubular secondary which contains the two primary fine wire coils F, F.
The secondary or heavy section conductor A, is formed as a liquid tight tube and
completely encloses the primary as shown.

page_text: The electrical terminals or poles of the secondary A, are formed at 5, where the
ends of the tubular secondary come close together, the general shape in outline of
the secondary being square or rectangular although this form may obviously be
departed from to any desired extent. The secondary as will be seen forms but
single turn of very heavy cross section.
At or near the poles or terminals 5, 5, are mounted suitable contacts 6, 6, bv
which current may be taken off from the secondary for any desired purpose. These
contacts 6, 6, are preferably formed as hemispherical blocks of copper accurately
ground into sockets on the secondary.
To form an endless tube which may serve as a liquid receptacle containing the
oil and primary the ends of the secondary are united at 5, by an insulating liquid
tight joint 7, of any suitable character. This joint may be a piece of wood or any
other suitable material, and may be rendered absolutely tight by any well known
cement poured between the metal and wood.
As will be seen from the drawings the secondary or heavy section conductor A,
consists of two metal channel castings fastened together by bolts at points 9. To
form a good joint between the two halves of the secondary when thus bolted
together a thin packing may be interposed between the halves at the joint. I do
not limit myself to the exact form of the castings and they might, if desired, be of
different shape in cross section if they both be adapted to form a tube when bolted
together around the primary.
It will be understood that the primary is applied in the groove or channel of une
of the castings and then the other placed over it to enclose it. The primary may
consist of any form of conductor but preferably is made of copper strips insulated
by asbestos, preferably asbestos cloth, and loosely wound to allow the asbestos to
take up the oil and to permit a partial circulation of oil therethrough. The
primary is held in position in the tube out of contact with the latter by means of
supports or distance pieces 10, distributed at proper points. Terminals of the
primary wire are indicated at 12. They pass through insulating bushings 13, in the
casting A, which bushings are properly constructed to form a liquid tight joint.
When the secondary has been placed around the primary and the proper liquid
tight joints formed, as described, it is filled with oil, connection with a reservoir or
supply pipe being maintained to allow for expansion under increase of temperature.
Preferably employ some heavy cylinder oil that shall stand as high a
temperature as 100 degrees Centigrade. The oil affords waterproof insulation and
a means for conveying heat away from the primary.
As shown the primary coil consists of a number of turns designed to produce
from a current of considerable tension a current of reduced potential but very large
volume in the secondary A.
The oil may be introduced through an orifice at 14, or any other point. H, is a
tube connected to such orifice and leading from any suitable reservoir I. The
tube H, may be a flexible copper tube and the reservoir or stand pipe may be
located at some distance from the transformer.
While it is preferable to make the secondary or heavy section element as an
endless tube by joining its ends through an insulating joint, it will be obvious that
my invention is not limited to such construction as the ends might be at some
distance from one another and the two free ends of the tube stopped independently
of one another. I prefer, however, to use the construction shown wherein the tube
is made endless, by bringing the terminals of the casting in close proximity and
joining them through an insulated joint. K, is the usual laminated iron core male
in two or more sections secured together aud threading the primary and secondary
as indicated at K.
In this transformer it will be seen that the maximum efficiency is obtained for a
given weight of copper inasmuch as the secondary completely surrounds the
primary coil so that the lines of force generated by the primary shall cut the
secondary to the greatest extent possible.

page_text: Having thus particularly described and ascertained the nature of my invenl
tion, and in what manner the same is to be performed, as communicated to me
by my foreign correspondents, I declare that what I claim is :-
1. An induction coil or converter having a secondary constituting a liquid
tight tube enveloping the primary and containing oil, as and for the purpose
described.
2. In an induction coil or converter, the combination with the primary, of a tube
enveloping the same and constituting the secondary, said tube having its ends united
by an insulating liquid tight joint to form a liquid receptacle, and containing oil, as
and for the purpose described.
3. The combination in a converter, of a primary having a number of turns and
a secondary consisting of a sealed metal tube enveloping the primary coil and
containing oil, as and for the purpose described.
4. In an electric transformer having a primary wound with a number of turns
and a secondary having but one turn and composed of a single tube which follows
the winding of the primary coil and forms a tubular envelope or jacket therefor
throughout substantially its whole length.
5. In an electric transformer, the combination with a primary having a number
of turns, of a secondary baving but a single turn enveloping the primary coil, aud
filled with oil, substantially as described.
6. In a transformer, a secondary consisting of two metal channel castings
fastened together to form a tube, in combination with a primary contained in
said tube.
7. In a transformer, a secondary having a single turn composed of two grooved
castings secured together to forin a tube containing the secondary.
8. In a transformer, the combination with a tubular secondary forming an oil
containing receptacle, of a primary enveloped thereby, and consisting of loosely
wound metal strips separated by asbestos.
9. In a converter, the combination with a tubular secondary, of an enclosed
loosely wound primary immersed in oil contained in said secondary, as and for the
purpose described.
10. In a converter, the combination with the primary, of a secondary consisting
of two solid copper castings bolted together so as to form a tube enclosing the
primary, the interior space being filled with oil, as and for the purpose described.
11. The combination, substantially as described, in a transformer, of a tubular
secondary enclosing the primary and filled with oil, and an oil reservoir or stand
pipe connected with said tubular secondary, as and for the purpose described.
12. The combination, substantially as described, with the tubular secondary,
of a primary supported out of contact with the tube by suitable distance pieces or
supports and immersed in oil contained in said secondary, as and for the purpose
described.
Deted this wash d... Ր
1002
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.