Improvements in connection with Channel Rails and Current Supply for Electric Tramways.
Year: 1899

page_text: Date of Application, 27th June, 1899
Complete Specification Left, 27th Mar., 1900-Accepted, 2nd June, 1900
Improvements in connection with Channel Rails and Current Supply
for Electric Tramways.
I, MICHAEL HOLROYD SMITH, of Albany Buildings, 47, Victoria Street, West-
minster, Consulting Engineer, do hereby declare the nature of this invention
to be as follows:-
The commercial utility of overhead conductors for electric tramways is well
known but the danger & risk to the public by their employment is not suffi-
ciently recognized.
.
Slotted or open conduits are in some cases prohibitory because of the cost of
construction.
Many surface contact systems have been devised fulfilling all that is neces-
sary for simple straight lines but all of them inapplicable at complicated junc-
tions, say where two double lines of tramway cross each other, and where the
cars have to run from one line to the other right & left (a condition which
obtains in many large cities such as London, Manchester etc.) and where it is
required to maintain a level surface of the road.
The object of this invention is to secure a method less costly than the slotted
conduit as ordinarily constructed and to secure the advantages claimed for the
best surface contact systems, and to eliminate all risk of electric shock to the
tramway passengers or general public.
For this purpose instead of the ordinary grooved girder rail now in common
use I employ a plain girder rail and in combination with it a guard rail so
placed and shaped that at the surface it leaves a slot or space similar to the
ordinary groove in which runs the flanges of the tram car wheels and below is
80 bent or curved as to leave sufficient space for the passage of ploughs or
plates carrying the electric collectors. Against this guard plate at suitable
intervals I place boxes containing electric switches carrying insulated studs
which pass through the guard rail into the hollow space between it and the
girder rail.
The ploughs or plates are suitably attached to the framework or body of the
car one near the front and one near the back and have a flexible rod, bár or
metal cord so connected to them that as the car progresses the metal cord is
drawn successively over the studs projecting into the hollow space & making
contact therewith gathering the electric engergy therefrom and conveying it
by suitable insulated conductors by the ploughs or plates to the controlling
switch on the car. The return circuit can be made through the rails, or both
rails may be constructed as above and two collecting ploughs be employed the
energy being collected from the studs on one side and returned by the studs
on the other side.
.
These studs may be energized directly from the generating station, or they
may be excited in groups by the passage of the car, or a switch may be pro-.

page_text: vided for each stud whereby each stud may be successively energized & de-ener-
gized as the car passes.
For the energizing of these studs any of the methods previously described by
me, or other methods may be employed, or any suitable modifications thereof.
Two important advantages arise from operating these studs by switches viz.
1st. Only those are energized that are required of the passing car, and as a
consequence the loss by leakage will be reduced to a minimum.
2nd. As the studs are only energized by the passing car the channel can
be cleared of dirt or obstruction at any time without risk of short-circuit.
As a modification of the above the ordinary grooved girder rail may be
employed, the guard rail forming a separate or additional groove or slot.
The boxes containing the switches that energise the studs may be placed at
a distance from the rail say near the curb-stone of the footpath & connection
be made between them & the studs by insulated wires.
J
ocil
22-
Improvements in connection with Channel Rails and Current Supply
for Electric Tramways.
I, MICHAEL HOLROYD SMITH, of Albany Buildings, 47, Victoria Street, West-
minster, Consulting Engineer, 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:---
The commercial utility of overhead conductors for electric tramways is well
known, but the danger and risk to the public by their employment is not suffi-
ciently recognized.
1
Slotted or open conduits are in some cases prohibitory because of the cost
of construction. Many surface contact systems have been devised fulfilling all
that is necessary for simple straight lines but all of them inapplicable at com-
plicated junctions, say where two double lines of tramway cross each other,
and where the cars have to run from one line to the other right and left, (a
condition which obtains in many large cities such as London, Manchester etc.)
and where it is required to maintain a level surface of the road.
The object of this invention is to secure a method, less costly than the slotted
conduit as ordinarily constructed and to secure the advantages claimed for 'the
best surface contact systems, and to eliminate all risk of electric shock to the
tramway passengers or general public.
The accompanying drawing Figs. 1 and 2, illustrate generally the nature of
this invention.
..
For this purpose, instead of the ordinary grooved girder rail now in common
use, I employ a plain girder rail A and in combination with it a guard' rail B
so placed and shaped that at the surface it leaves a slot C, or space similar to
the ordinary groove in which runs the flanges of the tramcar wheels and below
is so bent or curved as to leave sufficient space for the passage of ploughs or
plates. D. D¹ carrying the electric collectors. Within the channel so formed
studs E are placed as shown and supported by suitable insulators, these studs
may be connected direct to the supply cable or feeder wire F.
The ploughs or plates D, D¹ are suitably attached to the framework or body
of the car, one near the front and one near the back, and have a flexible rod
or bar or metal cord G so connected to them that as the car progresses the
1811

page_text: metal cord is drawn successively over the studs projecting into the hollow space,
and making contact therewith gathering the electric energy therefrom and
conveying it by suitable insulated conductors through the ploughs or plates
to the controlling switch on the car.
The return circuit can be made through the rails, or both rails may be con-
structed as above described, and two collecting ploughs be employed the energy
being collected from the studs on one side and returned by the studs on the
other side.
The studs may be energized directly from the electric generating station as
shown, or they may be energized in groups by the passage of the car, or a
switch may be provided for each stud whereby each stud may be successively
energized and de-energized as the car passes.
For the energizing of these studs any of the methods previously described by
be
me employing electric magnetic switches, or other suitable methods may
employed or modifications thereof. The methods may be generally described as
a combination of parts whereby the passage of the collector attached to the car
makes such contacts as to cause a current of electricity to flow round an electro
magnet of solenoidal or other construction the armature of which shall directly
or by its movement cause connection to be made between the insulated supply
cable and the exposed stud.
Two important advantages arise from operating these studs by electric
switches viz.-1st. Only those are energized that are required by the passing
car, and as a consequence, the loss by leakage will be reduced to a minimum.
2nd. As the studs are only energized by the passing car, the channel can be
cleared of dirt or obstruction at any time without risk of making a short circuit.
The boxes containing the electric switches that energize the studs may be
placed at a distance from the rail, say near the curbstone of the footpath and
connection can be made between them and the studs by insulated wires.
The studs may be neutral when in the normal position but electrically con-
nected with the supply cable as the car passes, by mechanical means means
A device for
such as by the employment of rocking arms, sliders or the like.
this purpose
is shown in Fig. 2 where B represents the girder forming the side
of the channel, A is an insulator passing through and fitted with a tube I, the
channel end J of which is dish shaped, the dish may be fixed to the tube or
be free to turn upon A. The other end of the tube enters a water-tight insu-
lating box. Through the tube passes a stud K free to revolve, the channel end
having a dished end K corresponding with J. The box end of the stud is
fitted with a collar L, the centre part of the stud is reduced in diametre to make
room for the coil spring M abutting against the ring N of the tube I and the
O shoulder 0 of the stud K, holding the collar L free from the terminal P con-
nected to the supply cable when the rod or cord G enters between the dishes J
and K. K' will be forced outward and draw the collar L against P making
connection with the terminal P' and thus with the source of electric supply.
As a modification of the general construction above described the ordinary
5 grooved girder rail may be employed. The guard rail forming a separate or
additional groove or slot.
0
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. In conduits for electric tramways the combination of a rail and channel
and insulated studs substantially, as and for. the purpose described and illus-
trated.
2. In conduits for electric tramways the combination of a rail and channel
insulated studs, and contact making collector, substantially, as and for, the
55 purpose described and illustrated.
.
3. In conduits for electric tramways the combination of a rail and channel

page_text: containing studs insulated from the channel but electrically connected with
the source of supply, substantially, as and for, the purpose described and illus-
trated.
4. In conduits for electric tramways the combination of a channel
containing insulated studs and electro magnetic switches for connecting the
studs with the electric supply during the passing of the car, substantially, as
and for, the purpose described and illustrated.
5. In conduits for electric tramways the combination of a. channel
containing insulated studs so constructed that the mechanical contact of the
collector shall cause the stud to make electric contact with the source of supply,
substantially as and for the purpose described and illustrated.
Dated this 26th day March 1900.
M. HOLROYD SMITH.