Improvements in and relating to Railway Signals.
Year: 1888

page_text: Date of Application, 11th Oct., 1888
Complete Specification Left, 10th July, 1889-Accepted, 24th Aug., 1889
PROVISIONAL SPECIFICATION.
Improvements in and relating to Railway Signals.
We, SAMUEL TELFORD DUTTON, of Marl Bank, in the city of the county of
Worcester, Civil Engineer and HENRY JAMES PRYCE of 18, Ickburgh Road, in the
county of Middlesex, Civil Engineer do heroby declare the nature of this invention to
be as follows:-
Our invention relates to railway signals.
Railway signal arms are now generally counterbalanced to rise to the danger
position should the connections break so that in rising during the ordinary operation
of the signals they acquire considerable momentum by the time they reach the limit
of their motion when arrested by the balance lever coming in contact with the
stop or any other stop that may be provided, which arrestation produces a shock to
the arm fittings and spectacles and frequently causes breakage such breakage being
attended with risk besides considerable wear to the working parts.
Our invention has for its object to soften and minimise the said shock sustained
by railway signal arms, fittings and spectacles due to the momentum imparted to
them on being moved as above stated, the wear and tear being at the same time
considerably reduced.
In carrying out our invention instead of connecting the crank on the arm spindle
or the arm plate to the balanced lever by a rigid and continuous rod as hitherto we
use a connecting medium having some degree of elasticity in it and we have obtained
good results by employing a connection in the form of a coiled spring, the axis of
which may be the arm spindle or the connecting pin of the signal rod.
To keep the jointed end of the spring within proper distance of the arm spindle
we can employ a radial link moving freely on the arm spindle or boss of the spring
and coupled to the signal rod joints together with the spring, a stop being provided
clear of the ordinary movement of the link to enable it to act upon the arm on the
down pull of the signal rod in case of failure of the other connection thus providing
an additional means of moving the arm to danger.
In the case of spectacles which are separated from the arm they may be suspended
from the signal rod by a coiled spring, one end being attached to the rod, the other
to the spectacle.
In some cases we adapt our elastic connection to the vertical rod by employing a
bracket carrying two levers (one underneath the other) fixed. to the signal post.
These levers are respectively attached to the upper and lower portions of the vertical
rod by means of ordinary joints, the ends of the levers being connected by a spring,
and to ensure the arm going to danger when any part should fail a pair of slotted
inks is attached to the levers connecting them together, the slots in the links being
adjusted to allow the amount of play that may be considered necessary. Or we may
employ a spiral spring or springs contained in a box inserted in the vertical rod.
It will be obvious that our invention can be carried out in various ways to suit
he particular kind of arın fittings to which it is to be applied.
Dated the 11th day of October 1888.

page_text: •
COMPLETE SPECIFICATION.
Improvements in and relating to Railway Signals.
We, SAMUEL TELFORD DUTTON, of Marl Bank, in the city of the county of
Worcester, Civil-Engineer, and HENRY JAMES PRYCE, of 18, Ickburgh Road, 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:-
Our invention relates to railway signals."
Railway-signal arms are now generally counterbalanced to rise to the danger
position should the connections break, so that in rising during the ordinary operation
of the signals they acquire considerable momentum by the time they reach the limit
of their motion, where they are arrested by the balance lever coming in contact with
a stop, which arrestation produces a shock which causes considerable wear to the
working parts, and frequently the breakage of the arm fittings and spectacles, such
breakage being attended with risk.
Our invention has for its object to soften or minimise the shocks sustained by
-railway-signal arms, fittings and spectacles due to the momentum imparted to them
on being moved, as above stated, and at the same time to considerably reduce the
wear and tear.
In carrying out our invention, instead of connecting the crank on the arm-spindle,
or the arm-plate to the balance lever by a rigid and continuous rod, as hitherto, we
use a connecting medium having some degree of elasticity in it, as hereinafter
described.
In the accompanying drawings-
Figure 1 is a front elevation of a portion of a railway signal provided with our
improvements.
Figure 2 is a side elevation of the same.
Figure 3 is a view similar to fig. 1, illustrating a modified form of flexible
connection; and,
Figuro 4 is a view of a detail of the same.
Figures 5, 6 and 7 are views illustrating other modifications; and,
Figure 8 is a view of a detail of the arrangement shown in figure 7.
Figure 9 is a view illustrating another modification.
Similar letters of reference indicate corresponding parts in the several figures.
a is the signal-post; the signal-arm pivotted on a spindle c carried in brackets d
secured to the post; e is a set of spectacles connected to the arm b; and fis the rod
extending from the balance-lever to the arm and operating the same.
A shown in figures 1 and 2, the flexible connection is in the form of a coiled
spring g, one end of which is secured to thes pindle c, while the other end is connnected
to the rod f. With this arrangement, when the rod is moved downwards to raise
the arm, the said spring takes up the motion, which is then gradually given off to the
spindle and thence to the arm. To prevent the arm from falling to the "off" or
"line clear" position, in case the spring should break, we provide the lever h,
which is secured to the spindle c and connected at one end to the rod f, and on the
signal-arm we form a projection i working in conjunction with the other end of the
said lever. So long as the spring is intact the projection i does not come into
contact with the lever h, should, however, the spring break, the arm would fall
slightly until the projection came in contact with the said lever, but not sufficiently
to place the arm in a false position. The said lever / being attached to the spindle c
and rod falso serves to maintain the jointed end of the spring at a proper distance
from the arm-spindle.
In the modification of our invention, shown in figures 3 and 4, the spring g is
provided with two coils, as shown in figure 4, the said coils being connected to the
pinj, to which the rod f has heretofore been connected.

page_text: In the modification shown in figure 5, the spring g, instead of being connected
directly to the signal-arm, is connected to one end of a lover or crank, the other
end of which is secured to the spindle c.
Spectacles which are separate from the arm, as shown in figure 5, may be
suspended from the rod by a spring, one end of which is connected to the rod, and
the other to the arm e¹ of the spectacles.
In some cases, instead of arranging our flexible connection in combination with
the signal-arm, as hereinbefore described, we adapt the same to the vertical rod f.
A shown in figure 6 we employ a bracket 1, carrying two levers m m¹ and fixed to
the signal-post; these lovers are respectively jointed to the upper and lower
portions of the vertical rod, the ends of the levers being connected by a spring n.
To ensure the arm going to danger in case the spring should fail, a link o is
attached to the levers connecting them together, a slot of being formed in the said
link to allow any play that may be considered necessary.
If desired a spiral spring may be arranged between the upper and lower portions of
the rod, and in practice we sometimes employ the adjustable spring connection, shown
in figure 7. This connection comprises a spring p into each end of which is
inserted a socket 9, internally screw-threaded to receive the correspondally screwed end
of the rod f, and having on its exterior threads to fill the spaces between the con-
volutions of the spring, as shown in figure 8. We make no separate claim, however
to this device in this Specification as it forms the subject matter of an application
dated 8th July A.D. 1889, No. 10982.
In some cases it may be advisable to enclose the spring p in a tube or box to
prevent the said spring from bending or buckling.
In all the arrangements hereinbefore described the spring serves not only to
minimise the shock, which occurs when the arms return to the danger position, but
also as a cushion when the arm is put to the "off" position.
In the modification of our invention, shown in figure 9 we provide an independent
cushion for minimising any shock which may occur owing to the momentum of the
arm when the signal is put "off" or lowered. In this modification, two
springs are placed in a box or tube s, which latter is connected to the lower
portion of the rod f. The upper portion of the rod fis provided at the end with a
piston or collar t which bears upon the spring *.
The spring is located above the piston t and is held in place by the cap s¹ of the
tube s, through which the upper part of the rod f slides.
In operation the spring takes the pressure while the rod f is being moved
upwards to put the signal "off" and the spring acts as the cushion to neutralize
the momentum of the arm; while when the arm is being moved to the "on' ог
danger position the spring * neutralizes the momentum of the arm.
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We wish it understood that we do not confine our invention to the particular forms
of flexible connection, herein before described, as it is obvious that other formos may be
employed. It is also obvious that our invention can be carried out in various ways
to suit the particular kind of arm-fittings, to which it is to be applied.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what
we claim is :-
(1) In a railway-signal connecting the signal-arm to the rod by means of which
the same is operated, by a medium having some degree of elasticity.
(2) The use for connecting the arm of a railway-signal with the operating rod, of
a coiled spring, arranged substantially in the manner hereinbefore described.
(3) Arranging the spectacles of a railway-signal, when mounted independently of
the signal-arm, in conjunction with a flexible connection, substantially in the manner
hereinbefore described.
(4) The modification of our invention wherein the flexible connection is introduced
into the operating rod, substantially as, and for the purpose, specified.

page_text: (5) The use in combination with the arm operating rod of a railway signal of a
spring or springs, substantially as described.
(6) The improvements relating to railway signals, hereinbefore described and
illustrated in the accompanying drawings.
Dated the 9th day of July 1889.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicants.