Improvements in Interlocking Apparatus for Railway Signalling.
Year: 1897

page_text: Improvements in Interlocking Apparatus for Railway Signalling.
I, ARTHUR GEORGE EVANS, of 116, Palace Chambers, Westminster, in the County
of Middlesex, Civil Engineer, do hereby declare the nature of this invention to be
as follows: -
My invention has reference to improvements in interlocking machines for rail-
way signalling purposes and consists in actuating the locking tappet by means of
the main lever without however it travelling with said lever. The movement of
the tappet is very much reduced.
In the ordinary type of lever locking machines the tappet is attached to the
main lever of the apparatus and moves with it through its travel. It is therefore
unsafe to put notches on the same side of the tappet at nearer intervals than the
distance the tappet travels, usually from 6 to 10 inches. One of the objects of
catch-handle or preliminary actuation locking was to get over this difficulty.
The way in which I carry out my invention is as follows:-
I attach preferably to the lever a segment having a notch at each end the notch
nearest the lever having a raised lip or projection at the side nearest the lever
the notch at the opposite end of said segment having a corresponding raised pro-
jection or lip at the side of the notch farthest from the main lever. Above this
segment is a shaft about which revolves a forked lever the forked end of which
works in connection with the segment, the upper end of said forked lever being
connected to a locking tappet which latter moves through the ordinary channel
iron locking bars. In the normal position of the main lever the right hand arm
or prong of the forked lever is in the notch in the above mentioned segment farthest
from the main lever the left hand arm or prong being raised above the segment.
When the main lever is moved it carries the segment with it and the lower or near
side of the farthest notch from the main lever tilts the right hand prong or arm of
the forked lever out of said notch; both arms or prongs then rest on the segment
and during the travel of the lever no movement is imparted to the tappet; by this
action the tappet has been moved and the locking effected. When the main lever
has completed its movement the notch in the segment nearest the main lever is
presented to the left hand arm or prong of the forked lever and the raised lip or
projection on the side of said notch nearest the main lever forces said left hand arm
or prong (of the forked lever) thus giving a further tilt or movement to the forked
lever and the locking tappet, this last movement of the tappet completing the
releasing.
The putting back of the main lever is similar in its operation of the forked lever
and tappet, as was the initial movement of the lever from its normal position to
the worked position, that is to say, the putting back of the main lever replaces the
tappet to its normal position and consequently the locking.
Although I have referred to the right and left hand prongs of the forked lever

page_text: it is obvious that this depends upon the position from which said forked lever is
seen.
JOHN P. O'DONNELL, Fel, Chart. Inst. P.A.,
Agent for said Applicant.
70 and 71, Palace Chambers, Westminster, S.W.
Improvements in Interlocking Apparatus for Railway Signalling. .
I, ARTHUR GEORGE EVANS, of 116, Palace Chambers, Westminster, in the County
of Middlesex, Civil 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 has reference to improvements in interlocking machines for railway
signalling purposes and consists in actuating the locking tappet by means of the
main lever without however it travelling with the said lever. The movement of
the tappet is very much reduced.
In the ordinary type of lever locking machines the tappet is attached to the main
lever of the apparatus and moves with it through its travel. It is therefore unsafe
to put notches on the same side of the tappet at nearer intervals than the distance
the tappet travels, usually from 6 to 10 inches. One of the objects of catch-
handle or preliminary actuation locking was to get over this difficulty.
The way in which I carry out my invention is as follows, reference being had
to the accompanying drawing, which illustrates a side view of an interlocking
frame comprising my improvements.
I attach preferably to the lever a, a segment b, having notches cc at each end;
the notch c nearest the lever having a raised lip or projection d at the side nearest
the lever a the notch c¹ at the opposite end of said segment 6 having a corre-
sponding raised projection or lip at the side of the notch c¹ farthest from the
main lever a. Above the segment b is a shaft e on which works a forked lever f
the forked end of which works in connection with the segment b, the upper end fl
of said forked lever being connected to a locking tappet g of the usual kind, which
latter moves through the ordinary channel iron locking bars. The shaft e pre-
ferably extends the whole length of the locking frame. In the normal position of
the main lever a the right hand arm or prong h of the forked lever f is in the
notch in the above mentioned segment b farthest from the main lever, the
left hand arm or prong h¹ being raised above the segment. When the main
lever a is moved it carries the segment with it and the inner or near side j of
the farthest notch c' from the main lever tilts or forces the right hand prong
or arm h of the forked lever f out of said notch; both arms or prongs h h¹ then
rest on the segment b and during the travel of the lever no movement is imparted
to the tappet; by this action the tappet has been moved upwards and the locking
effected in the usual manner. When the main lever a has completed its movement
the notch c in the segment nearest the main lever is presented to the left hand arm
or prong h¹ of the forked lever f and the raised lip or projection d on the side of
said notch c nearest the main lever being forced against the said left hand arm or
prong (of the forked lever f) gives a further tilt or movement to the forked
lever and the locking tappet in the same direction, this last movement of the
tappet completing the releasing.
The putting back of the main lever a is a reverse operation of the forked lever f

page_text: and tappet, that is to say, the putting back of the main lever a replaces the tappet
to its normal position and consequently the locking normal.
Although I have referred to the right and left hand prongs of the forked lever f
it is obvious that this depends upon the position from which said forked lever
is seen.
My invention can be applied to any type of interlocking machine.
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:-
In interlocking apparatus for railway point and signal levers, a rocking forked
lever such as f, connected to the interlocking tappet and operated by a segment
such as b, attached to and fixed above the fulcrum of the point and signal lever,
substantially as herein described, and illustrated.
JOHN P. O'DONNELL, Fel. Chart. Inst. P.A.,
Agent for the said Applicant.
70 and 71, Palace Chambers, Westminster, S.W.
JOHN P. O'DONNELL, Fel. Chart. Inst. P.A.,
Agent for the said Applicant.
70 and 71, Palace Chambers, Westminster, S.W.