Improvements in Electric Switch Mechanism for Surface Contact Electric Railways.
Year: 1898

page_text: Date of Application, 15th Nov., 1898-Accepted, 25th Feb., 1899
Improvements in Electric Switch Mechanism for Surface Contact
Electric Railways.
I, JOHN MCLEOD MURPITY, of Torrington, in the County of Litchfield, and
State of Connecticut, United States of America, Electrician, 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 is in the nature of an improved electro-magnetic switch
mechanism for surface contact electric railway systems having sectional con-
ductors and adapted to receive its initial movement by a local source of electrical
energy carried on the car.
One of the main objects of my invention is to so arrange the contact making
devices that the switch will be practically non-arcing, in making and breaking
the main or feed current. In the drawings:-
-
Fig. 1 is a diagram illustrating my improved switch devices used in connection
with an electric switch having no supplemental sectional conductors, brushes etc.
Fig. 2 is a diagrammatic view illustrating the same in use with a system
having supplemental conductor rails, etc.
Fig. 3 is a plan view of my improved switch mechanism.
Fig 4 is a view illustrating the switch head as having broken the local or
energizing circuit and before closing the main line circuit.
Fig. 5 shows the position of the head when the main line circuit is closed.
Fig. 6 is a diagrammatic view illustrating one of the switches, the circuit con-
necting it with the sectional conductor, trolley, and the battery current, and the
controller or cut-out devices.
The switches may be arranged in pairs, and located at regular points on the
line or concentrated at stations. In the construction shown, I indicates a switch
box, having compartments a-b, in each of which is held a set of switch devices.
Each switch mechanism embodies a pair of magnets 3 having an inner high
resistance winding 3, and an outer low resistance winding 3.
One terminal of the inuer winding connects with a post 4, having a wire 4",
connecting with the ground rail 5; while the other terminal of such winding
has a post connection 6, and passes through an adjustable spring plate 7, to arm-
ature lever 8, pivoted at 8, and having its head 8, normally engaging with
one 9 of a pair of opposing contacts 9-9", one of which 9, through lead 10 con-
nects with the sectional conductor rail 11, as shown. The plate 7 has a platinum
contact point 7".
The inner winding is energized by the storage battery circuit 12, on the car,
having its lead through the controller 13, trolley 14, and conductor 11. Thus
when controller closes the storage battery circuit, the current passes in the direc-
tion indicated by arrows 1-2 3 4 5 6 7-8, through controller, trolley,
sectional conductor, lead 10, switch lever 8, magnets and lead 4, to ground rail.
When magnets are thus energized, the switch lever is drawn over and engages

page_text: contact 9, which is electrically connected with outer windings 3b, and through
lead 16, with feed wire 17.
The co-relation of contacts 9-9, the switch head 8b, and contact plate 7, is
such that head 8b will positively break contact with plate 7, before it engages
contact 9, whereby to positively cut out the storage battery circuit from inner
windings before the main circuit is shunted through the low resistance winding,
it being manifest that as the contact of plate 7, with lever 8, is of a minimum,
but a minimum amount of arcing occurs at this point and whatever leakage there
is at such point will be from the storage battery current.
Thus, as the lever head moves in the direction indicated by the arrow in
Fig. 4, when it reaches the midway position, its contact with plato 7, is broken
and the local circuit cut out, it being obvious its forward momentum carries
it over into contact with member 9", which immediately re-energizes the magnets
from main line and holds switch to its thrown position.
The arrangement shown provides that head 8, at all times be in touch with
contact 9, and in consequence as the armature lever head is never separate from
contact 9, it follows, that when the circuit in the main line is broken and the
low resistance windings and contact 9, thereby de-energized, that whatever
current remaining in the conductor section will be grounded through head 8b,
member 7, high resistance winding 3", and ground rail 5, and as head 8" is
always in contact with member 9, a more positive engagement thereof with con-
tact 9*, is effected and danger of arcing or leakage from main line current by
reason of irregular cutting in of such current with the trolley contact rail, re-
duced to a minimum.
The wire 10 also forms the lead for the main line current from contacts 9-9"
(through head 8b) to the working conductors.
When used in connection with shunting systems having supplemental con-
ductor rails, brushes, etc., as shown in Fig. 2, the local circuit and lead 20, is
connected to the contact 9-the lead 10 in this case being used only for the main
line circuit.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what.
I claim is:
1. An electro-magnetic switch mechanism; comprising an electro-maguet
having a high resistance coil in circuit through its armature lever to the contact
rail and the ground or return rail, and a low resistance coil connecting the feed
wire and the conductor rail, means for energizing the high resistance coil to
throw the armature to close the main line or low resistance circuit, and a contact
common to both the low and high resistance circuits held in continuous engage-
ment with the armature switch in its different vibratory movements.
2. An electro-magnetic switch mechanism, comprising electro-maguets, an
armature switch, a main line circuit having contacts engaged and closed by the
shifting of the armature switch, a local circuit for energizing the magnets to
throw the switch, said local circuit having a contact member continuously held
in engagement with the switch during its vibratory movement.
3. The combination of the main line circuit, a local or energizing circuit, elec-
tro-magnets having windings in both the local and main circuits, an armature
switch lever, an adjustable connection joining such lever with the local circuit,
arranged to become disconnected from the lever when such lever is moved by
the local or initial energy in the magnets, and contacts in the main line adapted
to be electrically joined by the lever as it is drawn over by the initial energy
of the magnets.
4
4. The combination with the doubly wound magnets, the local circuits con-
nected to the inner windings, the main line circuit connected with the outer
windings of such magnets, said main circuits having contacts 9-9", of the s

page_text: switch having a head continuously in engagement with the contact 9, and the
contact plate 7, normally held in engagement with the switch and having limited
forward swing movement therewith and in electric connection with the local
circuit.
5. The combination with the magnets having outer and inner windings, the
contacts 9-9, the lead 10, connected with contact 9, the main circuit connected
with contact 9 and the outer magnet winding, the local circuit connected with
the inner windings of the magnet, the switch lever 8, having its head continu-
ously in engagement with the contact 9, the adjustable plate 7, and means for
energizing the local circuit.
Dated this 15th day of Norumb 1898