An Improvement in Railway Signalling Apparatus.
Year: 1887

page_text: Date of Application, 11th Feb., 1887
Complete Left, 31st Oct., 1887
Complete Accepted, 2nd Dec., 1887
PROVISIONAL SPECIFICATION.
An Improvement in Railway Signalling Apparatus.
We, JOHN SAXBY and JOHN STINSON FARMER, both of Canterbury Road, Kilburn
in the County of Middlesex, Engineers, and HENRY KIRBY, of No. 52 Eden Grove,
Holloway in the County of Middlesex, Engineer, do hereby declare the nature of this
invention to be as follows:-
li often occurs on railways that there is a signalling connection from one signalling
cabin to another at some distance from it, and that this connection is used not only
for working an indicator to shew that the line is clear or blocked, but also to lock or
unlock a lever or set of levers for working the signals to control trains. It may
happen that, one of the signalmen having given to the other an indication of "line
clear" and having thereby unlocked his levers so that he may pass a train, omits to
reverse the indication and that thus the second signalman may be misled and pass
trains when he should not do so. This invention relates to means of so operating the
indicator in such cases, and the locking gear of the signal levers, that the second
signalman having once lowered signals to pass a train and having moved the lever
to restore them to their "danger attitude, by this act alters the indicator to shew
"line blocked" and cannot again move his signal levers until a fresh indication of
"line clear accompanied by a fresh unlocking of his levers is transmitted from the
other cabin. For this purpose, the signal lever that is locked or unlocked by the
movement of the indicator is provided with a loaded or spring pawl which, in
the act of pulling over the lever to lower the signal, escapes a detent mounted on a
vertical rod that extends up to the indicator and carries the lock of the signal lever;
but by the act of putting back the lever in restoring the signal to the "danger
attitude, the pawl engages the detent and moves it aside so that the indicator rod
descends altering the indicator to shew "line blocked" and locking the signal
lever, which remains locked until it is again released by the signalman at a distance.
Tlated this 11th day of February 1887
ABEL & IMRAY,
Agents for the Applicants.

page_text: An Improvement in Railway Signalling Apparatus.
We JOHN SAXBY and JOHN STINSON FARMER both of Canterbury Road Kilburn
in the County of Middlesex Engineers and HENRY KIRBY of No. 52 Eden Grove
Holloway in the county of Middlesex Engineer do hereby declare the nature of our
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 on railways that there is a signalling connection from one
signalling cabin to another at some distance from it, and that this connection is
used not only for working an indicator to shew that the line is clear or blocked,
but also to lock or unlock a lever or set of levers for working the signals to control
trains. It may happen that one of the signalman having given to the other an
indication of "line clear" and having thereby unlocked his levers so that he may
pass a train, omits to reverse the indication, and that thus the second signalman
may he misled and pass trains when he should not do so. This invention relates to
«
means of so operating the indicator in such cases, and the locking gear of the signal
levers, that the second signalman having once lowered signals to pass a train and
having moved the lever to restore them to their "danger attitude" by this act alters
the indicator to shew line blocked" and cannot again move his signal levers until a
fresh indication of "line clear" accompanied by a fresh unlocking of his levers is
transmitted from the other cabin. For this purpose the signal lever that is locked or
unlocked by the movement of the indicator is provided with a loaded or spring pawl
which in the act of pulling over the lever to lower the signal, escapes a detent
mounted on a vertical rod that extends up to the indicator and carries the lock of the
signal lever but by the act of pulling back the lever in restoring the signal to
the "danger" attitude, the pawl engages the detent and moves it aside so that the
indicator rod descends altering the indicator to shew "line blocked" and locking
the signal lever, which remains locked until it is again released by the signalman at
a distance.
ог
Figs. 1, 2, and 3 of the accompanying drawings are side views shewing locking
apparatus according to our invention in three different conditions of its action. A is
a signal lever to which are jointed two bars C and B the one bar B carrying a
counterweighted pawl D and the other bar Chaving on it ratchet teeth. E is the
indicator which shews through an opening in its front either of the two signals
" blocked" (
clear" according as a sliding screen within its casing is lowered or
raised. From this sliding screen a stem F extends down and rests as shewn in Fig. I
upon the rounded end of a pawl G which is pivotted on a vertical rod H. The
stem F has on its side a projection which comes under a projection k from a
vertically sliding bar K, the lower end of which is bevilled. As shewn in Fig. 1
the indicator shews "blocked" and the bar K is engaged in the ratchet tooth of C
preventing the signal lever A from being moved. When the signalman at a distance
by means of a pull or otherwise raises the rod H, a projection h upon it lifts the

page_text: bar B and its pawl D, and the pawl G which is pivotted on H lifts the stem F
thereby changing the indication to "clear"; at the same time the projection f
acting on lifts the bar K out of the ratchet tooth of C and the signal lever A is then
free as shewn in Fig. 2. In pulling over the lever A the pawl B escapes the other
pawl G above it and the indicator remains shewing "clear" as shewn in Fig. 3.
On putting back the lever A, the pawl D moves G so as to release the stem F and
thereupon the screen descends to shew "blocked," also the bar K descends and
re-engages with the ratchet teeth on Clocking the lever A notwithstanding that the
rod H may still be raised. And until the rod H has been lowered and again raised
the signal lever A remains locked and the indicator continues to shew "blocked."
According to a modified arrangement of which in two conditions Figs. 4 and 5
are side views. Fig. 6 being a part end elevation and Fig. 7 a plan, A the signal
lever has pivotted to it a vertical rod forking into two branches B and C the latter
having ratchet teeth on its edge. H. is the rod which when raised by the action of a
signalman at a distance moves a bell crank L. This by a link moves a pawl G
which is engaged on a projection N from another link m jointed to a second bell
crank M. To the horizontal arm of the bell crank M is jointed the stem F of the
indicator, which is therefore raised to indicate "clear" when H is raised. By the
same movement of the link ma shoulder m¹ near its end coming to bear against
the fork B causes C to be moved so that its ratchet teeth are taken out of engage-
ment with a fixed catch P. The signal lever A is then free to be moved to the
position shewn in Fig. 5. In so moving it a detent D which is pivotted between
B&C escapes the pawl G. On putting back the signal lever A, the detent D lifts the
pawl G away from N and thereupon the screen of the indicator E descends shewing
blocked," also as the link m moves to the left a projection at N which pushes the
fork B and C back so that the ratchet teeth of Cagain engage with the catch P.
The signal lever A is thus locked and cannot be moved again notwithstanding that
the rod H may still remain raised. Nor can the signal lever A be moved again until
the rod H has been lowered and again raised.
Having now particularly described and ascertained the nature of our invention
and in what manner the same is to be performed we declare that what we claim is :-
In railway signalling apparatus wherein a signal lever is locked or unlocked by
action from a distance which works also an indicator, in combination with the signal
lever the indicator and the rod which works the indicator, detents pawls or catches,
so arranged that when the signal lever has once been pulled over and put back, it
remains locked back, and the indicator is made to shew "blocked" until the
indicator rod is again moved from a distance to shew “clear,” substantially as herein
described.
Dated this 31st day of October 1887.
ABEL & IMRAY,
Agents for the Applicants.