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

page_text: Date of Application, 22nd Oct., 1897
Complete Specification Left. 22nd July, 1898-Accepted, 27th Aug., 1898
PROVISIONAL SPECIFICATION.
Improvements in Overhead Lines of Electric Tramways or Railways.
I, PHILIP DAWSON, of 39, Victoria Street, in the City of Westminster, Civil
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in the overhead lines of electric tram-
ways and railways in which trolleys or their equivalents (I will refer to them as
trollies) are employed for conveying the electric current from the line wire or
conductor to the motor or the tramcar or other vehicle, and the invention has
for its object to provide a frog in which there are no moving parts the line wire
leading to the proper branch district being selected at the points by the whole
of the trolley itself.
situated
onl
one
According to this invention the frog plate is formed with a guide or track
which branches off into what will be termed even and uneven gauged lines,
the even gauge leading to one district and the uneven gauge to another district.
For a vehicle going to one district a trolley wheel is provided with a corres-
ponding even gauge and for a vehicle which is to branch off to the other dis-
trict the trolley wheel is provided with a corresponding uneven gauge. The
even gauge on the frog is formed with a guide or track situated centrally
between side grooves, while the uneven gauge which is made to branch
this
formed
is
track
off from
with the guide or
side or the other out of the centre line between its side grooves. The trolley wheel
for passing over the even gauge has a central groove with side flanges so as to
take into the even gauged line and pass onto one branch track, while the trolley
wheel for the uneven gauged line has its groove situated out of the centre line
on one side or the other so that when such trolley wheel passes onto the frog it
will be guided by its groove onto the uneven gauge and so pass onto the other
branch track. In place of the tracks on the frog with even and uneven gauges
I may form broad and narrow gauged tracks with trolley wheels made to corre-
spond. Guards on each side of the grooves of a track on the frog may be
advantageously employed for guiding the trolley wheels and keeping them in
their proper grooves.
00
1
antahan 1907
COMPLETE SPECIFICATION,
Improvements in Overhead Lines of Electric Tramways or Railways.
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
TD 017

page_text: what manner the same is to be performed to be particularly described and
ascertained in and by the following statement:-
-
This invention relates to improvements in the overhead lines of electric tram-
ways and railways in which trollies or their equivalents (I will refer to them as
trollies) are employed for conveying the electric current from the line wire or
conductor to the motor or the tramcar or other vehicle, and the invention has
for its object to provide a frog in which there are no moving parts, the line wire
leading to the proper branch district being selected at the points by the wheel
of the trolley itself.
According to this invention the frog plate is formed with a guide or track
which branches off into what will be termed even and uneven gauged lines,
the even gauge leading to one district and the uneven gauge to another district.
For a vehicle going to one district, a trolley wheel is provided with a corres-
ponding even gauge and for a vehicle which is to branch off to the other
district the trolley wheel is provided with a corresponding uneven
gauge. The even gauge on the frog is formed with a guide or track
situated centrally between side grooves while the uneven gauge which is
made to branch off from this, is formed with the guide or track situated on one
side or the other out of the centre line between its side grooves. The trolley wheel
for passing over the even gauge has a central groove with side flanges so as to
take into the even gauged line and pass on to one branch track, while the trolley
wheel for the uneven gauged line has its groove situated out of the centre line
on one side or the other, so that when such trolley wheel passes on to the frog it
will be guided by its groove on to the uneven gauge and so pass on to the other
branch track. In place of the tracks on the frog with even and uneven gauges
I may form broad and narrow gauged tracks with trolley wheels made to corre-
spond, guards on each side of the grooves of a track on the frog may be
advantageously employed for guiding the trolley wheel and keeping them in
the proper grooves.
The invention will be best understood by reference to the accompanying draw-
ings in which
Figure 1 is a plan of the underside of one of my improved frogs.
Figure 2 is a longitudinal section on the line 2-2 of Figure 1 and
Figures 3 and 4 are transverse sections on the line 3-4 of Figure 1 shewing the
two different forms of trolley wheel employed in conjunction with the said frog.
Like letters of reference indicate like parts throughout the drawings.
I form the improved frog of a plate A of brass or similar metal having at its
underside guides or ribs A2 A2. The guides or ribs A¹ A2 are preferably curved
as shewn in Figure 1 so as to turn the trolley wheels gradually instead of abruptly
as has hitherto been the case where the frog branches have been straight and so as
to reduce the angle which the branch trolley wires require to make with the end
of the frog plate; in existing arrangements wherein the branch trolley wires are
bent at a comparatively sharp angle at the ends of the frog plate, the said wires
frequently break at those parts. To assist in turning the trolley as last described
and provide against the trolley wheels leaving the guides or ribs A¹ A², I provide
the plate A with downwardly depending flanges or guards a¹ which, by acting on
the casings in which the trolley wheels are mounted, serve to direct the trolleys
on to the branches.
The guards or ribs A A' as shewn in Figure 2 incline upwards as they approach
the point of junction so as to allow the flanges of the wheels B B¹ to engage with
gradually deepening grooves a a³ formed at the central part of the plate A on
either side of the said guides or ribs. The groove a³ for directing the trolley wheel
on to say the branch A2 is at a distance from that branch greater than are the
grooves a from the other branch say A¹. The trolley wheel B for travelling along
the guides or ribs A forming a continuation of say the main line of trolley wire
are formed symmetrical the flanges 6 of each such wheel being equi-distant from

page_text: the wheel groove b¹ as shewn in Figure 3, and the trolley wheels B¹ Figure 4 for
running from the entering end of the guide or rib A¹ on to the guide or rib A²
leading to say the branch line of trolley wire, are each formed unsymmetrical,
the flange be thereof being at a distance from the wheel groove b¹ greater than
the flange as shewn clearly in Figure 9.
°
By these means only the trolley wheels B of symmetric form will, as shewn in
Figure 3, engage with both its flanges 6 with two of the plate grooves a (one
on either side of the ribs A¹) and consequently only those wheels will be guided
cn to the continuation of the main line of trolley wire, and only the trolley
wheels B of unsymmetric form will engage with the groove a³ as shown in
Figure 4 and be directed thereby on to the branch A².
Instead of the symmetrical and unsymmetrical arrangement of grooves a a³
and wheel flanges 6 62 before described I may form broad and narrow gauged
tracks and use trolley wheels made to correspond, under which arrangement each
trolley wheel or pair of trolley wheels will travel along the tracks of the particular
gauge corresponding to the said wheel or pair of wheels.
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 a³ 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 bottom 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 maintaining
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
travel. Further, although, as herein previously stated I prefer to curve the
guides or ribs A1 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 a³ 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 my said
invention and in what manner the same is to be performed, I declare that what
I claim is:
1. A frog for overhead conductors of electric railways or tramways the branches
of which are provided with grooves or guides of different gauge or arrangement
for engaging with the flanges of correspondingly different trolley wheels sub-
stantially so and for the purpose hereinbefore described with reference to the
accompanying drawings.
2. In a system of overhead conductors for electric railways or tramways the
employment in combination with frogs provided with grooves or guides of different
gauge or arrangement, of trollies having wheels of correspondingly different
gauge or arrangement substantially as and for the purpose hereinbefore described
with reference to the accompanying drawings.
3. A frog for use in connection with conductors of electric railways or tramways
constructed substantially as hereinbefore described and illustrated in the accom-
panying drawings.
Dated this 22nd day of July 1898.
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C., Agents.