An Improvement in Railway Signalling Apparatus.
Year: 1898

page_text: Date of Application, 18th Feb., 1898-Accepted, 19th Mar., 1898
COMPLETE SPECIFICATION.
An Improvement in Railway Signalling Apparatus.
I, WILFRED COSENS ACFIELD, of No. 4, Bedford Place, Croydon, in the County of
Surrey, Signal 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 :-
It often occurs that a railway signal has to be controlled by two separate and
independent signalmen, so that the semaphore arm cannot be lowered to " safety"
unless both signalmen operate their respective pulls for that purpose.
My invention relates to apparatus for effecting this double control, which can be
readily applied to existing balance lever plates of signals, and is so arranged that the
force applied to one of the pulls does not throw any strain on the other pull, and
that if one of the pulls or of the levers on which they act should accidentally give
way, the signal remains at "Danger."
I shall describe apparatus according to my invention, referring to the accompanying
drawings.
Fig. 1 is a front view with part broken off, Fig. 2 is a back view of the sleeve,
Fig. 3 is an end view and Fig. 4 is a plan partly sectional.
On a frame A which can be bolted against the signal post are mounted two
balanced levers B, C, to the ends of which are attached the two signal pulls D, E;
between these levers is mounted on the same axis a lever F to which is jointed the
vertical rod G which extends up to the semaphore. The lever F terminates in a cross
head H which extends under the rear arms of both the levers B and C. Each of the three
levers B,C and F, has an upright arm B₁,C,F¹. On the arms B¹ and C¹ are mounted anti-
friction rollers K, L, and on the arm F¹ is fitted a vertically sliding sleeve M. On the
front face of this sleeve is a concave projecting rib N with a hollow n at its upper part,
and on the rear face of M is a convex projecting rib P with a hollow p. When the parts
are in the position shewn, the signal is at "Danger," the sleeve M having its hollow n
resting on the roller K while the roller L is clear above the hollow p. If now the
pull D is operated, the roller K in coming out of the hollow n raises the sleeve M so
as to engage the roller L in the hollow p, and then the roller K in moving along the
curve under the rib N keeps the sleeve up with its hollow p engaging the roller L
and thus holding the signal lever F stationary. But if the pull D E is also operated,
then as the roller L is engaged in the hollow p the sleeve M and arm F¹ are
necessarily moved over raising the rod G and moving the semaphore to "Safety."
In like manner, if E is first pulled while the roller K is engaged in the hollow n,
the roller L, in travelling along the upper face of the rib P, prevents the sleeve M
and its rib N from rising out of engagement with K and therefore prevents the arm F
from moving, but when D is also pulled, the sleeve M and arm F¹ are moved over,
raising G and lowering the signal to "Safety."
By additional sliding sleeves and balanced levers, my invention can be made to
suit cases where a signal is controlled by more than two separate signalmen, as
required.

page_text: 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 :-
Signal apparatus for two independent signalmen constructed and operating
substantially as described with reference to the drawings.
Dated this 10th day of 1000
ABEL & IMRAY,
Agents for the Applicant.