Improvements in and connected with Electro-magnetic Contact Makers for Electric Traction with Underground Feed.
Year: 1896

page_text: Date of Application, 23rd Dec., 1896-Accepted, 13th Feb., 1897
COMPLETE SPECIFICATION.
Improvements in and connected with Electro-magnetic Contact
Makers for Electric Traction with Underground Feed.
I, REGINALD HADDAN of the Firm of Herbert Haddan & Co. 18, Buckingham Street,
Strand, W.C. London Patent Agent, do hereby declare the nature of this
invention a communication to me from abroad by Leon Piguet of 17-25 Rue de
Saint Cyr, Lyon Vaise in the Republic of France Constructive Engineer and in what
manner the same is to be performed to be particularly described and ascertained in
and. by the following statement :-
In this improved contact maker is utilized the property possessed by a solenoid
traversed by an electric current of attracting a magnetisable piece of iron, nickel etc.,
this piece serving for closing an electric circuit.
It further utilises the property which this magnetisable piece possesses of being
magnetized and of adhering strongly to another piece of magnetisable metal and thus
producing a better contact.
In the annexed drawings on Sheet 1 Fig. 1 is a sectional diagrun and Fig. 2 a plan
illustrating a system employing the improved contact maker. Figs. 3 and 4 are
similar views of a modified construction. On Sheet 2 Fig. 5 is a longitudinal vertical
diagram of a further modified form and on Sheet 3 Fig. 6 is a similar view of a
further modified form.
Referring to Figs. 1 to 4;-One of the extremities of the solenoid C is in
contact with the return wire or the rail H and the other extremity with a metallic
plate B.
A battery of accumulators N placed upon the car having one pole connected
with the wheels of the car and the other with a current collecting bar L placed
under the car and in contact with the metallic plate B, introduces an electrical
current into the solenoid C which attracts the metallic core G and closes the circuit
for the motor E by connecting the plate B1 and pin G. The current is received
from B1 by a second bar L1 in connection with the motor E of the vehicle.
One can suppress. one of the bars L L1 and use only one bar L by calculating
the resistance of the solenoid C so as to take only a weak derivation of the main
current; one can use for this a wire of great resistance such as ferro-nickel. The
plates B and B 1 are placed in the same axis (for instance the one may surround
the other as in Fig. 3-4) and the bar L can be flexible or composed of a multitude
of flexible metallic parts for instance forming a brush.
In Sheets 2 and 3 of the drawings the distribution of the current is also made by
means of an insulated conductor A buried in the middle of the track or at its side';
it is connected to above ground at certain distances by means of metallic boxes DI
with plates B and solenoids C attracting a pin G of soft iron or magnetised steel in a
permanent manner and producing contact between the conductor A and the plate B
by means of a ring D against which the shoulder E of the pin G presses the upper
part of this pin being then in contact with the plate B as shown on the left of
Fig. 5 & 6.
:
The two extremities of the solenoid C are in communication, the one with the
rail or return wire H and the other with the lower washer I of a pair of contact
washers, the under one of which I is of copper and the other J of magnetisable
metal, the latter is electrically connected with the plate B by a flexible metallic
wire J 1.

page_text: The plates are placed at distances apart inferior to the length of the contact
bar L fixed under the vehicle to be operated.
This flexible metallic bar rubs on the plates B and receives the necessary current
for the motors of the vehicle, which carries it.
Upon the carriage is a transformer M raising the tension of a small battery of
accumulators N to the normal tension adopted in the general circuit.
This transformer is intended to provide a current for exciting the solenoid at starting
or at any time that the contact may have become accidentally broken.
Before and behind the carriage to act immediately after the contact bar Lis
arranged an electro magnet O in order to cause the pin G to fall back.
A rubber P connected with the ironwork of the car terminates the car, it is
intended to produce a short circuit in the contact box D1 in case the apparatus
does not operate, and is provided for purposes of maximum security of action.
The operation of the car will therefore be as follows:
At the beginning the transformer M receiving current from the accumulators N
sends a current into the solenoids which are in contact with the contact bar L;
these solenoids attract their respective pins G and produce contact between the
underground conductor A and the plates B, the latter being magnetised by the pins G
draw up the movable disks J and breaking contact between J and I cut the solenoils
out of circuit; the pins G remain suspended being magnetised in a permanent manner.
The vehicle being in movement, the pins fall when they are in the field of the
electro magnets O the metallic plate B is then again insulated from the underground
conductor.
The rubber P will cause the fusion of the safety cut-out R holding the ring D if for
any reason the apparatus has not operated properly.
One can suppress the electromagnets O and replace them either by a bar magnetised
in a permanent manner or by electro magnets X (Fig. 6) excited by a derivation
of the main current in which case the pins G. are of soft iron..
The contact bar L on leaving one contact connects with another and communicates
the current to the solenoid of the latter and in case it misses a contact and thus
loses communication with the underground conductor the transformer M operated
by primary or secondary elements N will again excite the solenoid and reestablish
.the lost communication.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
In a system of electric traction with underground feed.
(1) The utilization of the property possessed by magnetisable bodies, such as iron,
nickel, etc., of being attracted in a solenoid traversed by an electrical current, for
producing contact between a surface plate and an underground cable.
(2) The utilization of the attractive property possessed by these bodies when
.attracted and placed in the solenoid for producing a perfect contact on closing the
circuit.
(3) A contact bar flexible or in the form of a brush in order to obtain a perfect
contact:..
:
(4) A pin magnetised in a permanent manner and attracted by a solenoid. excited
by an electric current intended to produce contact between an insulated underground
conductor and a metallic box or plate placed at the surface of the ground, this pin
producing in its ascension the breaking the circuit in the solenoid and reestablish
it by its fall, produced by means of a permanent magnet placed behind the carriage
or an electro magnet excited by a derivation of the main circuit.
(5) A pin of soft iron or magnetisable metal attracted by a solenoid excited by
an electrical current intended to produce contact between an insulated underground
conductor and a metallic box or plate arranged at the surface of the ground, this
pin producing in its ascension the breaking of the circuit and reestablishing it in
its fall and maintained in contact with the metallic plate by means of its magnetisation

page_text: produced by constructing it of a metallic magnetised bar of a permanent character or
by an electro magnet excited by a derivation of the main current.
(6) A battery of accumulators of weak tension operating a transformer raising the
tension at the normal tension of the general circuit, this current serving for exciting
the solenoids in the case of a fortuitous loss of connection between the underground
conductor and the metallic plate..
4
R. HADDAN,
Of the Firm of Herbert Haddan & Co.,
18, Buckingham Street, Strand, London, Agents to Applicant.