Improvements in the Method of Supplying Electricity to Electrically Propelled Tramcars and other Vehicles, and in Apparatus therefor.
Year: 1896

page_text: Date of Application, 9th June, 1896
Complete Specification Left, 9th Mar., 1897-Accepted, 5th June, 1897
PROVISIONAL SPECIFICATION.
Improvements in the Method of Supplying Electricity to
Electrically Propelled Tramcars and other Vehicles, and
in Apparatus therefor.
PERCIVAL JOHN PRINGLE of "Morningside "High View Road, Sidcup in the
County of Kent Electrical Engineer and JULIAN MONEY VERNON MONEY-KENT
of 34 Victoria Street Westminster Engineer, do hereby declare the nature of this
invention to be as follows:-
This invention consists of details and modifications relating to Percival John
Pringle's previous Patent No. 2274 of 1894 for "Improvements in the method of
supplying electricity to electrically propelled tramcars and other vehicles and in
apparatus therefor." In the previous invention a shunt current for actuating the
magnets of distribution is obtained by having the front collector on car connected
to the return rails through a comparatively high resistance. The action of the
front collector is fully described in connection with Figs. 4 to 10 inclusive.
Instead of this method of arranging the collectors and connections, we in many
cases prefer to use the following method which we will now describe:- Whatever
number of collectors are used they are all in electrical connection with one another
and supply current direct to motor on car through suitable switching and regulating
apparatus. The current after passing through motor returns by the rails. Each
distributor has a comparatively high resistance attached to that end of the bobbin
of each of its magnets which is not directly connected to the main supply, the
other end of each of these resistances being connected to the return rail.
"
When two adjoining surface conductors or "sections are momentarily connected
together by the collectors on the car the short circuiting action which takes place
is similar to that described in Patent 2274/94 in Figs. 4 to 10 inclusive, but on this
short circuiting action terminating however, the magnet immediately becomes
re-magnetised instead of in Fig. 4 to 10 this not occurring until the front collector
to which is connected the comparatively high resistance has been moved onto the
preceding section.
This arrangement of connections has the following advantages:-
That all collectors being utilised for conducting the main current to the motor
on car, the space that the first and last collector can bridge across with a given
length of car is therefore greater and a. corresponding reduction can be made in
the number of sections required per mile of track.
That by suitably adjusting the resistances of these comparatively high resistances
with the resistance of the magnets, it is possible to arrange that the voltage on
those sections adjoining the one directly connected to the main conductor by
the distributor, is sufficiently low not to affect the traffic in any way so that
these sections may be exposed beyond the base of the cars, thus allowing the
sections to be spaced further apart.
When a car has reached the last section of a block and is about to enter an
adjoining block to prevent the main switch arm of distributor being switched off
onto its insulated contact before the distributor in the adjoining block is brought
into action, we may employ an additional winding on the distributor magnets
which is in series with the feeder cable running from the last section to the
distributor.
The exciting power of this supplementary series coil is so, arranged that with

page_text: the magnet short-circuited, it will prevent the armature of same being released
until the main current supplied to the car is sufficiently small not to cause an
objectionable spark when the main switch arm of distributor is switched onto
its insulated contact. The surface conductors or "sections" referred to in
Patent 2274/94 we propose to construct as follows:-
To employ an iron conduit the top part of which contains a hard durable
substance of fairly good insulating properties such as asphalte, asphaltum
concrete etc., in which is embedded the surface conductors which are flat with the
road surface and of such a section as to be firmly held in the insulating substance.
Instead of relying on the insulating substance alone to retain the surface
conductors we may find it desirable to bolt or otherwise suitably attach the latter
to creosoted wooden beams or blocks laid or attached to the inside of top part of
conduit.
The lower part of iron conduit would be reduced in width so that it might
contain the feeder cables and if desirable the main conductor. An iron plate or
other substance would separate the top part of conduit containing the insulating
substance from the lower part containing the cables. These cables when laid in
conduit would have pitch or other waterproof insulating substance poured over
them.
The surface conductors being laid at intervals, the space between these would
either consist of the solid insulating substance or would have independent lengths
of rail similar to the surface conductors let into same so as to better take the
rubbing action of the collectors.under the tram car.
Dated this 8th day of June 1896.
PERCIVAL JOHN PRINGLE.'
J. M. V. MONEY-KENT:
Improvements in the Method of Supplying Electricity to
Electrically Propelled Tramcars and other Vehicles, and
in Apparatus therefor.
We, PERCIVAL JOHN PRINGLE, Electrical Engineer of "Morningside" Sidcup
in the County of Kent and JULIAN MONEY VERNON MONEY-KENT, Electrical
Engineer of Limetree House, Twickenham 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 :-
This invention consists of improved modifications and details relating to
Patent No. 2274/94 and granted to the above Percival John Pringle for
improvements in the method of supplying electricity to electrically propelled
tramcars and other vehicles and in apparatus therefor. In this previous invention
a shunt current of actuating the magnets of distributors is obtained by having the
front collector on car connected to the return rails through a comparatively high
resistance. The action of the front collector is fully described in connection with
Fig. 4 to 10 inclusive. Instead of this method of arranging the collectors and
connections we in many cases prefer to use the method which we are about to
describe. In addition to this we will also describe a form of conduit which shows
how we propose to carry out the connection between the collectors on car and the
various feeder cables running from distributors.
I
For the purpose of more particularly describing this invention we shall refer to
the several figures on the annexed sheet of drawings.
Fig. 1. shows diagrammatically the conuections when one car is being supplied
with current from one distributor.

page_text: part
the above
onnectic
are Carried OL
reversing distributor.
Fig. 3. shows diagrammatically in a simplified form the electrical connections
which occur in connection with the two distributors shown in Fig. 2.
Fig. 4. shows the connections in the case of a distributor which has only to
supply current to cars moving constantly in one direction.
Figs. 5 and 6 show longitudinal section, and cross-section respectively of conduit.
We will now proceed to describe the connections and. action of distributor in
relation to Fig. 1.
The connections here shown are similar to those in Fig. 4 of Patent No. 2274/94
with the exception that the resistance is stationary and directly connected to
magnet. M' of distributor, and the three collector brushes t' t2 and 3 are directly
connected together, all of them being for the purpose of directly supplying current
to motor T on car. With car in position as shown M' is magnetised by shunt
current flowing through and so attracting down rocking bar N. On car
advancing so that the front collector t³ comes in contact with section 5*,
magnet M¹ becomes short circuited, the current flowing through A to section 4,
then from collector t' to t, and then from section 5 direct to resistance r. As
soon as the car has advanced so that t' has left section 4* the short circuiting
connections are broken, and M' again becomes magnetised ready for a similar
action to occur.
The modification in the arrangements of the connections has the following
advantages, that all collectors being utilised for conducting the main current to
the motor on car the space that the first and last collector can bridge across with
a given length of car is therefore greater, and correspondent reduction can be
made in the number of sections required per mile of track.
In addition to this advantage that by suitably adjusting the resistance of and
resistance of the coils of magnet M' it is possible to so arrange that the voltage on
the section adjoining the one directly supplying current to the eur (for instance in
Fig. 1 this would be section 5") is sufficiently low not to be in any way dangerous
to the traffic. This permits therefore of the section in advance of the one supplying
current to the car viz. 5 being entirely exposed beyond the base of the car so long
as it is in connection with the junction of r and M. This again permits of the
sections being spaced much further apart than is possible with the arrangement as
described in Patent No. 2274/94.
We may also employ a supplementary winding on each of the magnets of the
distributor for the following purpose:-
Let us assume for argument that in Figure 1 section 4 is the last section of a
block which we will call A and that section 5" is the first section of the preceding
block B. Should the distributor controlling this preceding block be not ready to
come into action the main current supplying the motor on car would be broken
inside distributor supplying block A as soon as this was switched out of action.
To prevent this, the cable from contact 4 of distributor to section 4" would have
sufficient turns round the windings of M', so that the current flowing through it
(which would be the main current supplying car motor) if beyond an amount which
would not be advisable to break inside distributor would continue of its own accord
to hold in movable armature of M', and prevent the distributor being switched out
of action.
We will now refer to Fig. 2 which describes how the connections shown in Fig. 1
are carried out in the distributor.
D shows the distributor out of action. D2 shows an adjoining distributor
supplying current to section 1" which is just about to be put out of action, and
bring into action D.
The small rocking switch y', y' with the contacts 1 and 2 is similar to that
described in Patent No. 2274/94, under Fig. 19 20 and 21, but with the additional
contacts 3 and 4. When the bar of switch is horizontal neither of these latter are
in contact with y' and y. Suppose the end of bar y' is tilted as shown for

page_text: distributor D, then y' is in contact with 37 and 1', and y' is disconnected from 4'
as well as 2. Tilted the other direction the reverse occurs.
In Fig. 1. only one resistance r and one magnet was shown, bnt when distributor
has two magnete, as in Fig. 2, viz., M' and M 2 resistances r and
and they are connected to the additional contacts 3 and 4 as shown.
are required,
We will now explain how the resistances r and of each distributor are switched
in and out of action. The rocking switch of D has been tilted into the position
shown, when the main arm A was moved from insulated contact P2 to P (this
action is the same as described in Patent 2274/94 under Fig. 20, 21, and 22) and it
remains in this position, and continuing to put r in connection with M up to and
until the main arm A has revolved into P¹.
It will be seen that each distributor is fitted with main arm A, two shunt
arms A and A2, two supplementary shunt arms A" and A2, and the additional
small contact, and connections as described in Patent 2274/4 under Fig. 22. In
following the connections through in Fig. 2 it will be seen that M of D2 is
magnetised by current flowing through of D, and that by means of the shunt
arm A of D bridging across small contact C3 and C4, that M₁ of D' is put in
parallel with M' of D, and will therefore also be magnetised, and by the same
means small contact C is put in connection with small contact C, the latter which
is already connected to contact P by the supplementary arm A bridging across
these. We now have the two magnets M of D2, and M' of D' in parallel, anl
both magnetised by current flowing through of D2, and the junction of this
resistance with the two magnets, connected to section 24, which is the next
section in advance to the one supplying current to the car, vi, 1. These
connections are for the sake of clearness shown diagrammatically in Fig. 3. Now
on car advancing so that t' makes contact with 24 both magnets are short circuited,
and arm A of D2 moved onto P25, and its rocking switch moved into a horizontal
position disconnecting r from M at the same time the main arm of D' is moved on
to and its rocking switch tilted into the late position occupied by rocking
switch of D2, as shown in Fig. 2.
Now in distributor D, is put in contact with M by the new position of its
rocking switch, and is magnetised ready for a similar series of actions to take place
as is described in Fig. 1.
In the case of arm A of D' being on contact P2 and supplying current to 24" on
the car moving in the reverse direction, that is, onto section 1 a similar series of
connections and actions are performed as has just been described.
The various small connections required from D' to the distributor on its left, and
also the one from D2 to the distributor on its right are not shown in Fig. 2 for the
sake of clearness in the drawing.
Where cars are only required to travel in one direction one shunt arm and one
supplementary arm only are required such as A' and A", and in this case only one
resistance would be necessary, and the rocking switch omitted. The end of
resistance would instead of going to contact 35 (see Fig. 2) be taken to a contact
ring 57 (see Fig. 4) and the end of M' taken to another contact ring 6. On these
two rings would press the shunt arm A', and it is always in contact with both of
these during the revolution of the distributor except when main arm A is on P
when arm A' is then on the insulated piece 77, and is thereby disconnected from
resistance r. If r was not disconnected in this manner M would remain magnetised
after distributor was put out of action.
The connection between the car collectors, and the feeder cables ruuning from
distributors may be carried out by means of the small conduit shown in Fig. 5
and 6 where C is a rolled, or cast iron trough laid flush with the road surface in
this case shown as granite pitchings.
The depth of it can be so adjusted that it rests on the concrete bed T which is
laid for the granite pitchings standing on, this would entail only the latter being
disturbed when laying this frough. The lower portion of trough is slightly large
than the middle so as to be firmly dovetailed into the concrete T¹.

page_text: Separating the upper from the lower portion is a stout plate p which is laid:
throughout the whole length of the troughing. Where the sections S occur, this
plate carries the creosoted wood blocks W which are wedged into the top part of
troughing and, where connection is made from the feeder cables f to the sections it
is cut away as shown in Fig. 6. In between the sections we may either put in a
piece of dead section rail to give a smooth surface for collectors to rub along or
fill in the troughing entirely with some durable insulating substance such as asphalt
or asphaltum concrete which is shown at R. The section of the section rail is such
that it can be firmly bolted down by bolts to wood blocks w and will be firmly.
retained by the asphalte R bedded around it. The upper part of troughing is also
smaller at the top than it is lower down which assists in retaining the asphalte..
The lower portion of troughing may contain the feeder cables fan I also the main
supply conductor S' and its feeders if any." When these cables are laid the space
between them would be filled up with melted pitch or other such substance. The
troughing would break metallic joint every now and then so that should for any
reason one of the section rails become temporarily connected to the troughing there
would not be a sufficiently bad earth on the latter to cause a dangerous current to-
pass. This form of conduit has the advantage that only one narrow trench in the
road is required and if the road is paved with wood or granite it is not necessary to
disturb the concrete foundation under them. It is obvious that this form of
conduit is adaptable to any form of electric traction system wherein the current is.
supplied to cars from surface contacts or rails on the sectional or continuous third
rail system.
Having now particularly described and ascertained the nature of this inven--
tion and in what manner the same is to be performed we declare what we-
claim is :-
(1.) In the system of electric traction such as has been described in Patent.
No. 2274/94 granted to Percival John Pringle the employment of the modification
and improved arrangements of connections and parts:-
(a) Consisting of the stationary resistances a rocking switch the several.
connections from same being arranged and adapted to operate in conjunction
with the reversing distributor, feeders, sections, connections as described in
Patent No. 2274/94 substantially in the manner and for the respective-
purposes above set forth.
(b) Consisting of one stationary resistance two contact rings and the several
connections from same being arranged and adapted to operate in conjunction
with the distributor for car travelling constantly in one direction, feeders,.
sections, connections, as described in Patent No. 2274/94 substantially in.
the manuer and from the respective purposes above set forth.
(2.) The improved combination and arrangement of parts comprising 2 resistances,..
rocking switch, and the several connections from same operating substantially as
described in reference to Figs. 1, 2 & 4 and for the purposes herein set forth.
(3.) The improved combination and arrangement of part comprising 1 resistance,.
2 contact rings, and the several connections from same operating substantially as.
described in reference to Fig. 1 and 2 and for the purposes herein set forth.
(4.) The combination of an iron troughing the top part containing the section
rails and the lower part the several feeder and supply cables substantially as
described in reference to Fig. 5 and 6 and for the purpose herein set forth.
(5.) The arrangement of a supplementary winding on the magnets of distributors.
to prevent an excessive current being broken inside them substantially as described
and for the purposes herein set forth.
Dated this 9th day of March 1897.
PERCIVAL JOHN PRINGLE.
JULIAN MONEY VERNON MONEY-KENT..