Improvements in Electric Tramways or Railways on a Road Contact System.
Year: 1899

page_text: Date of Application, 23rd June, 1899
2000
PROVISIONAL SPECIFICATION.
Improvements in Electric Tramways or Railways on a Road Contact
System.
I, BENJAMIN JOSEPH BARNARD MILLS, of 23, Southampton Buildings, in the
County of London, Patent Agent, do hereby declare the nature of this invention
(a communication to me from Edouard Bonnet, Engineer, of 21, Place Bellecour,
Lyons, Jules Paufique, Contractor, of 15, Rue Saint Dominique, Lyons, and
Georges Liniere, Mechanician, of Ecully, Rhone, all in the Republic of France)
to be as follows:-
I will describe the invention by the aid of the accompanying drawing in
which Fig. 1 shows a vertical section of one of the main line contact boxes, one
of the tram or railway lines, a straight magnet or contact bar carried by a
vehicle, and a diagram of a compound winding of the straight magnet showing
the connections with a special battery and with the motors.
Fig. 2 is a vertical transverse section of a contact box, a straight magnet or
contact bar and lateral bars connected with the upper armature of the said
straight magnet.
Fig. 3 is a sectional view drawn at right angles to Fig. 2 and Fig. 4 is a
sectional elevation showing a modification of the straight magnet or contact bar.
The improvements are applicable to electric tramways or railways in which
the current is transmitted by means of a straight magnet, coming successively
into contact with metallic covered boxes flush with the ground, and causing, by
their magnetic action, the passage of the current to the said boxes.
In tramways or railways of this system, when the straight magnet comes into
contact with the cover of one of these boxes, it attracts a contact suspended .in
said box and connected by a flexible connection to the main electric conductor.
The current thus enters the carriage through the straight magnet, actuates
the motor, and returns through the rails.
The magnetization of the straight magnet is effected by a special source of
electricity, a primary or secondary battery carried by the carriage. The improve-
ments have for their object to reduce to the minimum the importance of this
source, by joining to it at the desired moment the excitation of the motor
current and by better utilising on the other hand, the magnetic field thus
created. The first of these conditions is realized by means of a compound wind-
ing arranged as indicated in diagram Fig. 1.
The electro magnets A which maintain the magnetization of the straight
magnet B, are excited in a continuous manner by the battery P, by means of a
primary winding p, p, sufficient only to obtain the attraction of the pin C, and
to maintain it in its contact position, a strong pressure of this pin against the
plug D not being necessary so long as the current taken by the carriage is
nothing.
m
in series with
The same electro magnets A receive a second winding m
the circuit of the motors, coming from the principal line E, passing through

page_text: the pin C, the straight magnet B, the motors M, and returning to the rails R.
The main current is established in this circuit as soon as the pin C is in
contact, and its action is then added to that of the battery to increase, the con-
tact pressure, in proportion as the current borrowed from the line is greater.
These arrangements would also be applicable if the electro-magnets excited
by means of a special constant current were replaced by permanent magnets.
The power of these latter would then be reduced to that sufficient to establish
simply the contact of the pin C.
The motor current coming as previously described increases, at the useful
moment, the pressure of this contact.
The contact pin C is carried by a cast iron ring provided with wings I see
Figures 2 and 3 embedded in the masonry of the box and rising towards the
surface of the ground; it is by these wings that the return is established of
the magnetic field to the poles S of the electro magnets opposed to the poles N
in contact with the straight magnet.
This return across a mass of air of considerable resistance is very defective
from the magnetic point of view, we have remedied this by bringing the poles S
of the electro-magnets near the wings F, by means of the arrangement shown
at Figures 2 and 3. The straight magnet B, Fig. 2 is placed between two
lateral bars B¹ B¹ in communication with the upper armature of the electro-
magnet, and consequently forming two poles of contrary name to that of the
principal or straight magnet. The winding of the wire of the electro magnet
thus arranged, can take place on vertical pieces as in Fig. 2 or on horizontal
pieces as shown at Fig. 4 or in any other manner provided that the principal or
straight magnet forms a pole of contrary name to those of the lateral bars 13¹ 'B¹
The bars B pass at a little distance from the wings F, which in itself con-
siderably reduces the resistance to the return of the magnetic field, but this
resistance can be further diminished, by rendering magnetic the parts G of the
box within which the wings F rise, and which are opposite the bars B. This
result is obtained by forming these parts of an agglomeration containing debris
of magnetic bodies, from which the wings F are electrically insulated, by cover-
ing them with a layer H of enamel, asbestos, or other insulating body.
To the arrangements represented at Figures 2 and 4 can readily be added the
compound winding the principle of which is indicated at Fig. 1.
In the arrangement shown at Fig. 2, the coil A would receive the winding
fed from the special source and the coils A¹ would be traversed by the motor
current. In the arrangement shown at Fig. 4 each coil would be divided into
two, those A, A, traversed by the current from the special source, those A'A¹
traversed by the motor current.
It may also happen that the surface of the ground being rendered conductive
by any given cause, such as water, salted snow &c., a current is established
between the rails and the plug D, at the moment when this latter comes into
contact with the pin C. This current being interrupted at the falling of the
pin C, there might result from it a cause of rapid deterioration of the pin.
This inconvenience is avoided by applying to the two ends of the straight
magnet B, see Fig. 3, an element M of conducting but non-magnetic metal, such
as copper, bronze, &c. Under these conditions when the magnetized part of the
straight magnet has left the plug D, the pin C falls but without interrupting
the superficial current which, borrowed from the following box, is prolonged
during the contact of the additional element M with the plug.
Dated June 23rd 1800
HARRIS & MILLS,
23, Southampton Buildings, London, W.C., Agents.

page_text: Improvements in Electric Tramways or Railways on a Road Contact
System.
I, BENJAMIN JOSEPH BARNARD MILLS, of 23, Southampton Buildings, in the
County of London, Patent Agent, do hereby declare the nature of this invention
(a communication to me from Edouard Bonnet, Engineer, of 21, Place Bellecour,
Lyons, Jules Paufique, Contractor, of 15, Rue Saint Dominique, Lyons, and
Georges Liniere, Mechanician, of Ecully, Rhone, all in the Republic of France)
and in what manner the same is to be performed to be particularly described
and ascertained in and by the following statement:-
I will describe the invention by the aid of the drawings accompanying my
Provisional Specification, in which Fig. 1 shows a vertical section of one of the
main line contact boxes, one of the tram or railway lines, a straight magnet or
contact bar carried by a vehicle, and a diagram of a compound winding of the
straight magnet showing the connections with a special battery and with the
motors.
Fig. 2 is a vertical transverse section of a contact box, a straight magnet or
contact bar and lateral bars connected with the upper armature of the said
straight magnet.
Fig. 3 is a sectional view drawn at right angles to Fig. 2 and Fig. 4 is a
sectional elevation showing a modification of the straight magnet or contact bar.
The improvements are applicable to electric tramways or railways in which
the current is transmitted by means of a straight magnet, coming successively
into contact with metallic covered boxes flush with the ground, and causing, by
their magnetic action, the passage of the current to the said boxes.
In tramways or railways of this system, when the straight magnet comes into
contact with the cover of one of these boxes, it attracts a contact suspended in
said box and connected by a flexible connection to the main electric conductor.
The current thus enters the carriage through the straight magnet, actuates
the motor, and returns through the rails.
The magnetization of the straight magnet is effected by a special source of
electricity, a primary or secondary battery carried by the carriage. The improve-
ments have for their object to reduce to the minimum the importance of this
source, by joining to it at the desired moment the excitation of the motor
current and by better utilising on the other hand, the magnetic field thus
created.. The first of these conditions is realized by. means of a compound wind-
ing arranged as indicated in diagram Fig. 1. The electro magnets A which
maintain the magnetization of the straight magnet B, are excited in a continuous
manner by the battery P, by means of a primary winding P, P, sufficient only
to obtain the attraction of the pin C, and to maintain it in its contact position, a
strong pressure of this pin against the plug D not being necessary so long as the
current taken by the carriage is nothing.
The same electro magnets A receive a second winding m. m, in series with
the circuit of the motors, coming from the principal line E, passing through
the pin C, the straight magnet B, the motors M, and returning to the rails R.
The main current is established in this circuit as soon as the pin C is in
contact, and its action is then added to that of the battery to increase the con-
tact pressure, in proportion as the current borrowed from the line is greater.
These arrangements would also be applicable if the electro-magnets excited
by means of a special constant current were replaced by permanent magnets,

page_text: The power of these latter would then be reduced to that sufficient to establish
simply the contact of the pin C. The motor current coming as previously
described increases, at the useful moment, the pressure of this contact.
The contact pin C is carried by a cast iron ring provided with wings F see
Figures 2 and 3 embedded in the masonry of the box and rising towards the
surface of the ground; it is by these wings that the return is established of
the magnetic field to the poles S of the electro magnets opposed to the poles N
in contact with the straight magnet. This return across a mass of air of con-
siderable resistance is very defective from the magnetic point of view, this is
remedied by bringing the poles S of the electro magnets near the wings F, by
means of the arrangement shown at Figs.
and 3.
The straight magnet B Fig. 2 is placed between the lateral bars B'B' in
communication with the upper armature of the electro magnet, and consequently
forming two poles of contrary name to that of the principal or straight magnet.
The winding of the wire of the electro magnet thus arranged, can take place on
vertical pieces as in Fig. 2, or on horizontal pieces as shown at Fig. 4 or in any
other manner provided that the principal or straight magnet B forms a pole of
contrary name to those of the lateral bars B, B.
The bars B pass at a little distance from the wings F, which in itself con-
siderably reduces the resistance to the return of the magnetic field, but this
resistance can be further diminished, by rendering magnetic the parts G of the
box within which the wings F rise, and which are opposite the bars B'. This
result is obtained by forming these parts of an agglomeration containing debris
of magnetic bodies, from which the wings Fare electrically insulated, by cover-
ing them with a layer H of enamel, asbestos, or other insulating body.
To the arrangements represented at Figures 2 and 4 can readily be added the
compound winding the principle of which is indicated at Fig. 1.
In the arrangement shown at Fig. 2, the coil A would receive the winding
fed from the special source and the coils A¹ would be traversed by the motor
current.
In the arrangement shown at Fig. 4 each coil would be divided into
two, those A, A, traversed by the current from the special source, those A¹A¹
traversed by the motor current.
It may also happen that the surface of the ground being rendered conductive
by any given cause, such as water, salted snow &c., a current is established
between the rails and the plug D, at the moment when this. latter comes into
contact with the pin C. This current being interrupted at the falling of the
pin C, there might result from it a cause of rapid deterioration of the pin.
This inconvenience is avoided by applying to the two ends of the straight
magnet B, see Fig. 3, an element M of conducting but non-magnetic metal, such
as copper, bronze, &c. Under these conditions when the magnetized part of the
straight magnet has left the plug D, the pin C falls but without interrupting
the superficial current which, borrowed from the following box, is prolonged
during the contact of the additional element M with the plug.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is:-
:-
1) In an electric tramway or railway the combination with the motor con-
ductors, of a straight magnet making contact with current transmitting boxes
flush with the ground and reinforced at the desired moment by the motor current
substantially as herein set forth.
2) In an electric tramway or railway the combination with the motor con-
ductors, of a straight magnet magnetized by means of an electric source of small
power and reinforced at the desired moment by the motor current substantially
as herein set forth.
3) In an electric tramway or railway the combination with the motor con-

page_text: ductors of a straight magnet making contact with current transmitting boxes
flush with the surface of the ground and an auxiliary bar bringing the upper
poles of the straight magnet near the ground substantially as herein set forth
and for the purpose stated.
4) In an electric tramway or railway the combination with the motor con-
ductors, of a straight magnet making contact with current transmitting boxes
flush with the surface of the ground and conducting but non magnetic parts
connected to the ends of the straight magnet substantially as herein set forth
and for the purpose stated.
5) In an electric tramway or railway the combination of main line or con-
ductor, movable contact pin connected to such main conductor, a cast iron ring
provided with a guiding socket to carry such pin, wings attached to said ring
and rising to near the surface of the ground, a non-conducting box carrying
said ring and contact pin and having the said wings embedded therein, a con-
ducting plug closing the upper end of the box and a straight magnet carried
by the vehicle and connected with the motor conductors, substantially as herein
set forth and for the purpose stated.
1000
HARRIS & MILLS,
23, Southampton Buildings, London, W.C., Agents.