An Improved Frog for Overhead Conductors or Trollies of Electric Railways or Tramways.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
An Improved Frog for Overhead Conductors or Trollies of Electric
Railways or Tramways.
I, PHILIP DAWSON, of 39, Victoria Street, in the City of Westminster, Civil
Electrical Engineer, do hereby declare the nature of this invention to be as
follows:-
My invention relates to an improved frog for use in electric railways or tram-
ways with overhead conductors or trollies and has for its object to provide a
moveable frog for passing from a single line to a branch line with a positive
action operated from the trolley of the tramcar or like vehicle running beneath.
According to my invention I provide a boss or projection on the trolley
which on entering the frog or point strikes an arm depending from an axle
mounted on rollers which I will refer to as a carriage running in a box or casing
situated on one side of the frog. A sliding bar moving in guides is secured at
one end to the said carriage and is slotted to receive a lever arm to which is
attached the movable point of the frog; the sliding bar is provided with an
eye at its other end for taking into a hook or catch for retaining the same in
position. The boss or projection on the trolley striking the arm
moves the
carriage forward and with it the sliding part against a spring moving the lever
arm so that the point attached thereto is placed in its proper position for the
passage of the trolley wheel onto one of the branch lines or loops, the said arm
being held in this position by the eye of the sliding part taking on the hook.
In order to release the sliding bar from the hook and allow the parts to resume
their normal position after the passage of the trolley I provide a weighted arm
or lever fast on a spindle mounted in bearings on to which the shank of the
hook is also secured so that the projection on the passing trolley strikes against
the same and tilts it causing the hook to be depressed and the sliding bar under
the influence of the spring to be released, and returned to its normal position.
It will be understood that with cars not having the boss or projection on the
trolley there will be no movement of the frog and the trolley will therefore pass
over the frog onto the other of the branch lines or loops the parts thereof being
held in their normal position by the spring as aforesaid.
D: 001 ins of Dotobar 1897
JOHNSONS & WILLCOX,
47, Lincoln's Inn Fields, London, W.C.

page_text: An Improved Frog for Overhead Conductors or Trollies 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 ascer-
tained in and by the following statement:-
-
My invention relates to an improved frog for use in electric railways or tram-
ways with overhead conductors or trollies and has for its object to provide a
moveable frog for passing from a single line to a branch line with a positive
action operated from the trolley of the tramcar or like vehicle running beneath.
According to my invention I provide a boss or projection on the trolley
which on entering the frog or point, strikes an arm depending from an axle
mounted on rollers which I will refer to as a carriage running in a box or casing
situated on one side of the frog. A sliding bar moving in guides is secured at
one end to the said carriage and is slotted to receive a lever arm to which is
attached the moveable point of the frog; the sliding bar is provided with an
eye at its other end for taking into a hook or catch for retaining the same in
position. The boss or projection on the trolley, striking the arm, moves the
carriage forward and with it the sliding part against a spring, moving the lever
arm so that the point attached thereto is placed in its proper position for the
passage of the trolley wheel onto one of the branch lines or loops, the said arm
being held in this position by the eye on the sliding part taking on the hook.
In order to release the sliding bar from the hook and allow the parts to resume
their normal position after the passage of the trolley I provide a weighted arm
or lever, fast on a spindle mounted in bearings on to which the shank of the
hook is also secured so that the projection on the passing trolley strikes against
the same and tilts it, causing the hook to be depressed and the sliding bar under
the influence of the spring to he released and returned to its normal position.
It will be understood that with cars not having the boss or projection on the
trolley there will be no movement of the frog and the trolley will therefore pass
over the frog onto the other of the branch lines or loops the parts thereof being
held in their normal position by the spring as aforesaid.
The invention will be best understood by reference to the accompanying
drawings in which
Figures 1 and 2 are plans of respectively the under and upper sides (Figure 2
having a portion broken away) of one of my improved frogs which in Figure 3
is shewn in side elevation and
Figs. 4 and 5 are longitudinal sections both taken on the line 4-5 of Figure 2
looking in the direction indicated by the arrow 2 and shewing the apparatus as
at different stages of its operation.
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 A1 A2 along which, in the ordinary way, travel the
flanged trolley wheels which latter are not shewn in the drawings. At the
underside of the plate A I provide a moveable tongue e having a vertical pivot es
extending through and free to oscillate in the said plate so as to allow the
tongue to swing in a horizontal plane to enable it to be moved into either of its
two operative positions. When in its normal position as shewn in full lines in
Figure 1, the tongue e connects the two sections of the main track A¹ and when
in its other position as shewn in dotted lines in Figure 1 the said tongue con-

page_text: nects the track A¹ with the branch A³. On the upper end of the pivot e³ I secure
a lever arm f the swinging end of which engages with an opening g, Figures 4
and 5, of a sliding bar G moving in one or more guides as in a box or casing A5
conveniently cast in one piece with the frog plate A. To one end of the bar G
is adjustably secured a pivot rod g¹ carrying rollers g2 adapted to travel along
tracks on the upper and lower sides of the box or casing A5 the said rollers g³
and the pivot rod g¹ constitute, and are hereinafter referred to as, a carriage"
the letter being used to designate these parts when thus referred to.
$
On the pivot rod g¹ between the rollers g² is pivotted a lever g3 g of which
the arm hangs downwards through a slot a in the frog plate and bottom of the
casing A5 and the arm g carries a roller g which, during the first part of
the stroke of the carriage g, bears against the upper side of the casing A5 as
shewn in Figures 3 and 4, and during a later part of the same stroke passes
through a slot a¹0 Figure 2 in the said upper side of the casing as shewn in
dotted lines in Figure 5. The lever arm is so situated as to enable it to be
operated on by a projection provided on each of the trollies intended to travel
from the track section on to say the branch A2. The sliding bar G is en-
circled by a spring G¹ which tends always (through the said bar G lever arm f
and pivot e), to hold the tongue e in the position in which it is shewn in full
lines in Figure 1 or to return it to that position after it has been moved to
establish communication between the branch A2 and main track A' as shewn in
dotted lines in Figure 1. The sliding bar G is provided with an eye capable
of engaging with a hook or catch h carried by a bar h¹ which is pivotted in lugs all
and also carries an arm H the free end of which is so situated as to allow the
said arm to be operated on by either the before described trolley projections or
other projections on the same trollies.
Instead of cutting the main line of trolley wire and sweating or soldering
the two severed ends to the ends of the frog plate A as has hitherto been necessary
I prefer to arrange the frog so that it may be fixed in position without removing
or cutting or appreciably bending or kinking the said wire. For this purpose I
form a groove a² in the top of, and extending throughout the length of, the
plate A and down into one of the guides or ribs A1 A2 and sweat or solder the
continuous or main line of trolley wire C in this groove and hold or clamp it
in the bottom thereof by tongue pieces or dogs C¹ inserted into the groove and
retained therein by cross pins c, the set screws c¹ of the dogs C¹ conjointly with
the pins
and serving to give the necessary pressure on the trolley wire.
The end of the branch trolley wire C2 is secured in the groove a³ in a manner
similar to that described in connection with the securing of the main trolley
wire in the groove a². By these arrangements the frog may readily be applied
to an existing trolley wire system without appreciably disturbing the latter.
The operation of the before described moveable frog is as follows:-
When a trolley provided with one of the before described projections travels
on to the frog the said projection strikes the lever arm g³ and carries it along
and through it moves the carriage 2 bodily onwards until the roller reaches
the slot alo at which juncture, as shewn in dotted lines in Figure 5, the said roller
passes through the slot and thereby allows the lever arm g³ to move out of the path
of the trolley projection which then passes onwards towards the arm H, the
lever resuming its normal position in relation to the bar G as soon as the
trolley projection has passed beneath it.
By these means the tongue e is moved over from the position in which it is
shewn in full lines in Figure 1 to that in which it is shewn in dotted lines in
that figure and the bar G is correspondingly moved from its normal position in
which it is shewn in Figures 2 and 4 into the position shewn in Figure 5 wherein,
for the desired period, it is retained against the influence of the spring G by
the engagement of the hook h with the eye g also as represented in Figure 5.
The trolley is thus directed on to the branch A and as it passes along the latter
the trolley projection abuts against and raises the free end of the arm H and

page_text: thus disengages the hook h from the eye 9º and allows the spring G¹ to move
the tongue and the parts operatively connected therewith, to their normal
positions so as to be ready for operation by the next following trolley which
is provided with the above mentioned projection; all trollies which are un-
provided with these projections do not affect the position of the tongue and pass
along the said tongue directly on to the main-track-continuation.
The arm H by its own weight or otherwise is caused to assume its normal
position as soon as the trolley projection leaves it.
If desired I may dispense with the before described trigger device comprising
the eye g and hook by providing means, either on those trolley heads which
are to operate the tongue e, or on, or in connection with, the lever arm g³ or
bar G whereby the tongue e may be retained in its deflected position until the
trolley leaves the frog; or if desired, the automatic frog may be arranged so
that every passing trolley will operate the tongue, each roller moving the said
tongue so as to make connection with the particular branch along which the
trolley is intended to travel, and the said frogs instead of having two branches
as shewn in the drawings may have 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. An adjustable frog for overhead conductors of electric railways or tram-
ways constructed so that a passing trolley may automatically adjust it in such
manner that the said trolley will be directed on to either of the trolley wire
branches connected to the frog substantially as herein before described.
2. An adjustable frog for overhead conductors of electric railways or tram-
ways constructed so that a trolley will automatically adjust it to direct the said
trolley on to the particular branch of trolley wire desired and afterwards return
the adjustable part or parts or allow of the return of the said part or parts to its
or their normal position substantially as hereinbefore described.
3. The combination with an adjustable frog for overhead conductors of electric
railways or tramways having means whereby it may be automatically adjusted
by a passing trolley so that the said trolley may be directed on to a particular
branch of the trolley wire, of a catch or trigger device for retaining the adjust-
able parts in their adjusted positions during the passage of the trolley and so
arranged that the trolley, when departing, will release it to allow of the adjustable
parts returning to their normal position, substantially as herein before described.
4. The combination and arrangement of parts constituting the adjustable
or moveable frog for use in connection with conductors of electric railways or
tramways substantially as herein before 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.