Improvements in the Construction of Overhead Lines of Electric Railways or Tramways.
Year: 1897

page_text: Pannlate Cannif
Date of Application, 22nd Oct., 1897
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1000
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PROVISIONAL SPECIFICATION.
Improvements in the Construction of Overhead Lines of Electric
Railways or Tramways.
I, PHILIP DAWSON, of 39, Victoria Street, in the City of Westminster, Civil
and Electrical Engineer, do hereby declare the nature of my invention to be as
follows:
: -
My invention relates to improvements in the overhead lines of electric railways
or tramways and more particularly to the arrangement and construction of
crossings and frogs for the overhead trollies which are employed in such systems
for conveying the electric current from the overhead line wire or conductor
to the motor on the tramcar or like vehicle. My invention is especially applicable
to systems in which swivelling trollies are used and has for its object to ensure the
smooth running of such trollies on the lines or tracks at the crossings or frogs with-
out sparking and to enable the line wires or conductors to he very readily and
efficiently connected to the said crossings or frogs.
I will describe my invention as applied to a crossing for an overhead trolley
but it will be understood that it is also applicable to frogs.
I form the crossing of a plate of brass or similar metal with grooves on each
side of the guide or track on which the flanged trolley wheel runs and I form the
said guides or tracks where they cross or intersect, with slanted or declining ends
the grooves taking the flanges of the wheel as they pass over and beyond the
slanting guides, I also provide depending flanges on each side of the track which
act as leaders and afford additional security, keeping the flanges of the trolley
wheel in the grooves at the crossing. I preferably form the guides or tracks
and the adjacent grooves with radial or S curves so that the wheels of the trolley
may pass more smoothly over the same and jerks liable to derail the wheels may
be avoided.
Instead of cutting the wires or conductors and sweating or soldering them to
each end of the crossing plate as hitherto I prefer to use continuous line wires
or conductors so arranged that the crossing plate may be fixed in position without
removing or cutting the said wires and the wires may run as straight as possible
without any appreciable kinking or bending at the crossing. For this purpose I
form the guides or tracks on the plate with elongated slots or grooves extending
from each end over the back of the said plate and I lay the line wires in these
grooves clamping or holding the same at the bottoms thereof by tongue pieces
which are dropped into the slots and held fast by set screws or cross pins. The
line wires or conductors are thus led across the back of the plate with but slight
curves in an almost even plane avoiding strains due to excessive bending.
Dated this 22nd day of October 1897.
JOHNSONS & WILLCOX.
47, Lincoln's Inn Fields, London, W.C., Agents.

page_text: Improvements in the Construction of Overhead Lines of Electric
Railways or Tramways.
I, PHILIP DAWSON, of 39, Victoria Street, in the City of Westminster, Civil
and Electrical 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:-
My invention relates to improvements in the overhead lines of electric railways
or tramways and more particularly to the arrangement and construction of
crossings and frogs for the overhead trollies which are employed in such systems
for conveying the electric current from the overhead line wire or conductor
to the motor on the tramcar or like vehicle. My invention is especially applicable
to systems in which swivelling trollies are used and has for its object to ensure the
smooth running of such trollies on the lines or tracks at the crossings or frogs with.
out sparking and to enable the line wires or conductors to be very readily and
efficiently connected to the said crossings or frogs.
I will describe my invention as applied to a crossing for an overhead trolley
but it will be understood that it is also applicable to frogs.
I form the crossing of a plate of brass or similar metal with grooves on each
side of the guide or track on which the flanged trolley wheel runs and I form the
said guides or tracks where they cross or intersect, with slanted or declining ends
the grooves taking the flanges of the wheel as they pass over and beyond the
slanting guides, I also provide depending flanges on each side of the track which
act as leaders and afford additional security, keeping the flanges of the trolley
wheel in the grooves at the crossing. I preferably form the guides or tracks
and the adjacent grooves with radial or S curves so that the wheels of the trolley
may pass more smoothly over the same, and jerks, liable to derail the wheels, may
be avoided.
Instead of cutting the wires or conductors and sweating or soldering them to
each end of the crossing plate as hitherto, I prefer to use continuous line wires
or conductors so arranged that the crossing plate may be fixed in position without
removing or cutting the said wires and the wires may run as straight as possible
without any appreciable kinking or bending at the crossing. For this purpose I
form the guides or tracks on the plate with elongated slots or grooves extending
from each end over the back of the said plate and I lay the line wires in these
grooves clamping or holding the same at the bottoms thereof by tongue pieces
which are dropped into the slots and held fast by set screws or cross pins. The
line wires or conductors are thus led across the back of the plate with but slight
curves in an almost even plane avoiding strains due to excessive bending.
I will describe my invention by reference to the accompanying drawings in
which:-
Figures 1 and 2 are plans of respectively the under and upper sides of one of
my improved crossings which is shewn in end elevation in Figure 3.
Figure 4 is a longitudinal section on the line 4-4 of Figure 1 and
Figure 5 is a plan of the underside of one of my improved frogs.
Like letters of reference indicate like parts throughout the drawings.
I form the improved crossing shewn in Figures 1, 2, 3 and 4 of a plate A of
brass or similar metal having at its underside, guides or ribs A' A² along which
travels the flanged trolley wheel B shewn in dotted lines in Figure 4. The guides
or ribs A¹ A2 as shewn in Figures 3 and 4 incline upwards as they approach the
point of intersection A³ so as to allow the flanges of the wheel B to engage with

page_text: gradually deepening grooves a formed at the central part of the plate A on either
side of the said guides or ribs. By these means the trolley wheel which, in the
ordinary way, travels along the guide or rib A¹ or A³ at one end of the crossing,
is directed with more certainty than has hitherto been possible with other arrange-
ments, over the point of intersection A³ and on to the other part of the same
guide or rib beyond such point and the tendency to jump off say the
guide or rib A¹ on to say the guide or rib A² or vice versa, which is experienced
with existing crossings is thereby minimised. To afford additional security against
the trolley wheel B leaving the guides or ribs A¹ A³, I provide the plate A with
downwardly-depending flanges or guards a¹ which, by acting on the casing in
which the trolley wheel B is mounted, serve to direct the trolley in the proper
direction.
Hitherto it has been usual to construct the crossings with straight guides or
ribs extending diagonally across them and with these it has been found that the
angle at the point of intersection is so small that the trolley wheels at that
point frequently pass on to the wrong guides or ribs and moreover the com-
paratively sharp bends given to the trolley wires where they are connected to
the extreme ends of the crossings frequently causes the said wires to break at
those parts. To overcome these difficulties I curve the guides or ribs in the
manner shewn in Figure 1 so as to increase the angle at their point of inter-
section A³ and reduce the angle to which the trolley wires require to be bent.
The projection or protuberance A³ provided at the point of intersection of the
guides or ribs also serves to maintain the guidance of the trolley wheel; this pro-
jection may be either of the prismatic form represented, or of any other desired
shape.
Instead of cutting the trolley wires or conductors and sweating or soldering them
to each end of the crossing plate A as has hitherto been necessary, I prefer to
arrange the crossing so that it may be fixed in position without removing or
cutting, or appreciably bending or kinking the said wires. For this purpose I
form grooves a² in the top of, and preferably extending more or less throughout
the length of the plate A and down into the guides or ribs A¹ A2, and I sweat or
solder the continuous trolley wires C (Figure 4) in these grooves, and hold or
clamp them in the bottoms thereof by tongue pieces or dogs C¹ inserted into the
grooves and retained therein by cross pins c, the set screws c¹ of the dogs C¹,
in conjunction with the pins c and c², serving to give the necessary pressure on the
trolley wires. The trolley wires C which cross each other at the centre of the
plate A as shewn in dotted lines in Figure 4, are thus led across the said plate A
with but slight curves in an almost even plane, thereby avoiding strains due
to excessive bending. By the last described arrangement the crossing may
readily be applied to existing trolley wires without any appreciable disturbance
of the latter.
In Figure 5 I have shewn a frog provided with the before described improve-
ments arranged for guiding a trolley wheel in the directions indicated by the
arrows either from a branch line A² on to the main line A³ or from one part of the
main line A' on to another part thereof beyond the junction with the branch line.
This arrangement will be sufficiently well understood from the foregoing descrip-
tion to render unnecessary any special explanation thereof.
The before described frogs may be modified without departing from the
essential features of the invention for example instead of forming them with
grooves such as a-and inclining the tracks A1 A2 so that the point of contact
of the trolley wheels with the frogs may be gradually transferred from the bottoni
of the trolley wheel grooves and summit of the tracks to the flanges of the trolley
wheels and plate A, an equally satisfactory result may be obtained by maintain-
ing a constant level of the tracks and inclining the plate A so that at the proper
time the trolley wheel will be moved down from the tracks and the trolley-wheel
flanges will bear on the plate, ribs being provided on the latter for guiding the
trolley wheel towards the particular track along which it is desired it should next

page_text: travel. Further, although, as herein previously stated, I prefer to curve the
guides or ribs A2 A2 as shewn in the drawings, I reserve to myself the right to
use straight guides or ribs, and if desired to extend the grooves a throughout
the length of the frogs or crossings, and, as will be readily understood the before
described improvements in frogs are not restricted to those having only two
branches, for with suitable modifications in the details of construction, the said
improvements are equally applicable to frogs having three or more branches.
Having now particularly described and ascertained the nature of this invention
and in what manner the same is to be performed, I declare that what I claim
is:
1. In a frog or crossing for overhead conductors or trollies of electric railways
or tramways, an arrangement whereby, in traversing the said frog or crossing
the trolley wheel has the point of contact therewith gradually transferred from
the bottom of its groove to its flanges and rice versa substantially as hereinbefore
described with reference to the accompanying drawings.
2. In a frog or crossing for overhead conductors or trollies of electric railways
or tramways the employment of a guard such assa¹ substantially as and for the
purpose hereinbefore described with reference to the accompanying drawings.
3. A frog or crossing for overhead conductors or trollies of electric railways or
tramways having curved trolley-wheel guides or ribs substantially as herein-
before described with reference to the accompanying drawings.
4. A frog or crossing for overhead conductors or trollies of electric railways or
tramways, grooved for receiving a conductor in such manner that the said frog
or crossing may be secured to the conductor without the latter being cut sub-
stantially as herein before described with reference to the accompanying drawings.
5. A crossing for overhead conductors or trollies of electric railways or tram-
ways having a projection or protuberance such as 13 at the point of intersection
of the tracks substantially as hereinbefore described with reference to the accom-
panying drawings.
6. In a frog or crossing for overhead conductors or trollies of electric railways;
or tramways the combination with a trolley-wire-groove extending throughout
the length of the said frog or crossing of a tongue-piece or dog such as C¹ capable
of being inserted into and removed from the said groove substantially as herein-
before described with reference to the accompanying drawings.
7. A crossing or frog for use in connection with conductors of electric railways;
or tramways constructed substantially as hereinbefore described and illustrated
in the accompanying drawings.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.