Improvements in Alternating Current Transformers.
Year: 1898

page_text: Date of Application, 26th July, 1898
Complete Specification Left, 30th Mar., 1899-Accepted, 26th July, 1899
PROVISIONAL SPECIFICATION.
Improvements in Alternating Current Transformers.
I, LEON MARIE JOSEPH CLEMENT LEVAVASSEUR, Engineer, of Suresnes, in the
French Republic, do hereby declare the nature of this invention to be as follows:-
This invention relates to alternating current transformers and consists in im-
provements which I shall describe referring to the accompanying drawings.
Figs. 1 and 2 shew forms to which plates are cut to constitute the laminated
magnetic circuits.
Figs. 3, 4 and 5 shew arrangements of these laminæ to form circuits of various
sizes, which are shewn in perspective by Figs. 6, 7 and 8.
Fig. 9 shews a wooden frame for folding the pieces of paper for insulating;
Fig. 10 is a section of a paper folded over two threads.
Figs. 11 and 12 are sections of primary and secondary bobbins arranged to
give equal values of flux.
Fig. 13 is a longitudinal section, Fig. 13 is an end view and Fig. 14 is a plan
of the part box H to contain the transformer.
Fig. 15 is a longitudinal section, Fig. 16 is a plan, and Fig. 17 is an end view
of the other part box I which is bolted to H.
Fig. 18 shews a plan and a side view of wooden frames interposed between the
boxes and the laminated piles.
Figs. 19 and 20 are side and end views of the complete transformer enclosed.
Fig. 21 shews one of the terminals.
The magnetic circuits consist of piles of plates A and B both eut in the form
of a carpenter's square, having limbs of equal width a, the two limbs of B
having equal lengths and the limbs of A being longer each equal to +a,
so that in putting the plates A and B together they form the four sides of a
square as shewn in Fig. 3, or two B plates or two A plates may form rectangles
as in Figs. 4 and 5.
Thus the piles may be made rectangular, of plates B as in Fig. 6, or square,
of plates A and B as in Fig. 7, or rectangular of plates A as in Fig. 8. In form-
ing the piles care should be taken to break joint, and one face of each plate
should have on it paper or insulating varnish.
The primary coil may consist of one bobbin or it may consist of several super-
posed bobbins with special insulators between them, each consisting of paper D)
(Fig. 10) or other suitable insulating material, folded over so that its edges nearly
meet at d, but the interval may be 1 or 2 millimetres.
A plate of suitable width being placed on the middle of the paper, the two
sides of the paper are raised a little and the paper is then placed in a wooden
mould E Fig. 9; two threads e e served with insulating material such as gumlac
are then placed in the bends, and the sides of the sheet are folded quite over,
the threads forming strengthening borders, and being of the same size as the wires
of the coil, serve to hold these in position. The exteriors of the bobbins are
insulated by bands of paper or fabric served with paraffin, gumlac, or other
insulating material. The secondary bobbins are similarly constructed.

page_text: In order that the flux which traverses the primary and secondary bobbins
may be equal, there may be, as shewn in Fig. 11, two primary bobbins F F with
a secondary G between them, or, as shewn in Fig. 12, two secondary bobbins G G¹
with a primary F between then.
The casing of the transformers consists of the two cast iron part boxes H and I
and two wood frames J, which, as shewn in Figs. 19 and 20. are held together
enclosing the transformer and its piles by four bolts K connecting the ears h
of H to the cars i of I, the frames J serving to insulate the piles of plates A and B
from the metal of H and I. In putting the parts together the primary and
secondary bobbins F and G the one within the other are placed in I which has
one of the frames J on its edge. The piles of plates A and B are then placed
on J and on them the second frame J, after which the other part box H is laid
on the upper frame J and the whole is firmly secured by the bolts K. The ends
of the bobbin wires are fixed to terminals one of which is shewn in Fig. 21. It
consists of a paper tube L surrounding the wire / which is soldered to a piece of
metal having a wire hooked to it, this being enclosed in a paper tube M.
Dated this 26th day of July 1898
ABEL & IMRAY,
Agents for the Applicant.
Improvements in Alternating Current Transformers.
I, LEON MARIE JOSEPH CLEMENT LEVAVASSEUR, Engineer, of Suresnes, in the
French Republic, 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 relates to alternating current transformers and consists in
improvements which I shall describe referring to the drawings accompanying
my Provisional Specification, and drawings filed herewith.
Figs. 1 and 2 shew forms to which plates are cut to constitute the laminated
magnetic circuits.
Figs. 3, 4 and 5 shew arrangements of these lamina to form circuits of various
sizes, which are shewn in perspective by Figs. 6, 7 and 8.
Fig. 9 shews a wooden frame for folding the pieces of paper for insulating;
Fig. 10 is a section of a paper folded over two threads.
Figs. 11 and 12 are sections of primary and secondary bobbins arranged to
give equal values of flux.
Fig. 13 is a longitudinal section; Fig. 13 is an end view and Fig. 14 is a plan
of the part box H to contain the transformer.
Fig. 15 is a longitudinal section, Fig. 16 is a plan and Fig. 17 is an end view
of the other part box I which is bolted to H.
Fig. 18 shews a plan and a side view of wooden frames interposed between the
boxes and the laminated piles.
Figs. 19 and 20 are side and end views of the complete transformer enclosed.
Fig. 21 shews one of the terminals.
Fig. 22 is a section to an enlarged scale shewing the insulating sheet with
threads.
Fig. 23 in its right half shews plates cut as in Figs. 1 and 2 and piled as in
Figs. 3, 4, 5 and 6, 7, 8, in its left half it shews a section of the two coils.
Fig. 24 is a plan shewing the coils F and G with the wires a x for G and y y
for F.

page_text: Fig. 25 is a plan of the piles of plates A and B and the primary and secondary
coils G and F.
The magnetic circuits consist of piles of plates A and B both cut in the form
of a carpenter's square, having limbs of equal width a, the two limbs of B
having equal lengths b and the limbs of A being longer each equal to b + a,
so that in putting the plates A and B together they form the four sides of a
square as shewn in Fig. 3, or two B plates or two A plates may form rectangles
as in Figs. 4 and 5.
Thus the piles may be made rectangular, of plates B as in Fig. 6, or square,
of plates A and B as in Fig. 7, or rectangular of plates A as in Fig. 8. In form-
ing the piles care should be taken to break joint, and one face of each plate
should have on it paper or insulating varnish.
The primary coil may consist of one bobbin or it may consist of several super-
posed bobbins with special insulators between them, each consisting of paper
(Fig. 10) or other suitable insulating material, folded over so that its edges nearly
meet at d, but the interval may be 1 or 2 millimetres.
A plate of suitable width being placed on the middle of the paper, the two
sides of the paper are raised a little and the paper is then placed in a wooden
mould E Figs. 9 and 22; two threads e e served with insulating material such as gum-
lac are then placed in the bends, and the sides of the sheet are folded quite over,
the threads forming strengthening borders, and being of the same size as the wires
of the coil, serve to hold these in position. The exteriors of the bobbins are
insulated by bands of paper or fabric served with paraffin, gumlac, or other
insulating material. The secondary bobbins are similarly constructed.
In order that the flux which traverses the primary and secondary bobbins
may be equal, these may be as shewn in Fig. 11 two primary bobbins F F with
a secondary G between them, or as shewn in Fig. 12, two secondary bobbins G G¹
with a primary F between them.
The casing of the transformers consists of the two cast iron part boxes H and I
and two wood frames J, which as shewn in Figs. 19 and 20 are held together
enclosing the transformer and its piles by four bolts K connecting the ears h
of H to the ears i of I, the frames J serving to insulate the piles of plates A and B
from the metal of H and I. In putting the parts together the primary and
secondary bobbins F and G the one within the other are placed in I which has
one of the frames J on its edge. The piles of plates A and B are then placed
on J and on them the second frame J, after which the other part box H is laid
on the upper frame J and the whole is firmly secured by the bolts K. The ends
of the bobbin wires are fixed to terminals one of which is shewn in Fig. 21. It
consists of a paper tube L surrounding the wire which is soldered to a piece of
metal having a wire 1 hooked to it, this being enclosed in a paper tube M.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim is :-
1. The modes of cutting the plates of alternating current transformers and
arranging them in piles as herein described with reference to Figs. 1 to 10
inclusive of the drawings.
2. The insulating bands of paper or other suitable material bent over cords, sub-
stantially as described.
3. The arrangement of secondary coil between two primary coils or of primary
coil between two secondary coils, substantially as and for the purpose set forth.
Dated this 28th day of March 1899.
ABEL & IMRAY,
Agents for the Applicant.