Improvements in Railway Signals,
Year: 1898

page_text: Date of Application, 31st Dec, 1898-Accepted, 4th Feb., 1899
Improvements in Railway Signals,
I, EDWARD TYER, of Ashwin Street, Dalston, in the County of London, 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 relates to such a construction and arrangement of the pulls and
rods which work a railway signal that, on a train entering a section of the line
the signal which was lowered to admit it is automatically raised to "danger" so as
to prevent another train from entering until the signal is again worked, and in
cases where the lowering of the signal has to be controlled from several different
points the pulls are rendered ineffective for lowering the signal unless permission
is electrically given from all these points.
I shall describe signal working mechanism according to my invention referring
to the accompanying drawinga.
Fig. 1 is an elevation and Fig 2 18 a plan of part of a railway line with connec-
tions for working the semaphore arm of a signal which with the post on which it is
mounted 18 drawn to a smaller scale. The other figures shewing details are drawn
to a larger scale than Figs 1 and 2, of these Figs 3 and 4 are respectively an
elevation and a plan of the separable parts of the pull in their connected condition
and Figs 5 and 6 are corresponding views of these parts in their disconnected con-
dition. Fig. 7 18 a part elevation shewing the parts in an intermediate position.
On a rocking shaft S mounted in bearings beside one of the rails R I fix a blade s
of elastic metal, and an aim loaded with a weight adjusted so as to hold the
blade s up so that its upper surface is on a level with the rail, and on the rocking
shaft in a closed box A beyond the rail I fix two upright bent arms and³.
Through the box A pass two sliding bars, the one P which forms part of the
signal pull, has its one end connected by chain pl passing over and under suitable
guide pulleys to the signal operating lever at a distance, and its other end connected
by a chain p passing over a pulley pa to a weight p The other sliding bar P¹
has its one end connected by a chain p passing over and under guide pulleys to
the one arm of a lever L which is pivotted at 7 on the signal post B and has on its
other end a weight l This lever is connected by a rod C to the crank arm d of
the semaphore D When the signal has to be controlled from only one place the
rod C is simply a continuous rod, but when it is to be controlled from more than
one place the iod C is made in parts as will be hereafter descubed so as to be in
some cases rendered ineffective in lowering the semaphore
A pawl E mounted on the bar P¹ has a lateral stud e engaged in a notch in a
slot of the bar P connecting the two bars PP so that they act together as a
continuous pull, as in Figs. 3 and 4, then on the chain being drawn from the
signal cabin pulling the bars PP to the left, the 10d C is raised lowering the
semaphore D to indicate "safety" When a train, in obedience to that signal enters
the section to which the signal applies the flange of its wheel in passing over the
blade depresses it causing the shaft S to turn partly round and moving the arm s
so that it raises the pawl E disengaging its stud e from the notch of the bar P and

page_text: 50 leaving the bar P¹ free The semaphore then in obedience to its counterweight
rises to "danger" allowing the load of the lever L to descend and draw the
bar P to the right as shewn in Figs. 5 and 6 When the blade s was depressed
the arm was moved from the position shewn in Figs 3 and 4 to that shewn in
Figs. 5 and 6 allowing a pawl F pivotted on the side of the box A to drop behind it
and hold it, so preventing the blade s from sing again. On the signalman now
Blackening the pull p¹, the bar P 18 caused by the weight to advance to the right,
so that the stude on the pawl E again engages in the notch of P coupling again
the two bars P and P¹, also an incline f at the left end of the slot of P
acting on a stud projecting from the side of the pawl F raises that pawl out of
the way of 3, and thereupon the weight causes the blade s to rise, the arm
moving back to the position shewn in Fig. 7 Thereupon a pawl G pivotted on
the side of the box A drops down in front of preventing it from moving to the
right and so preventing the blade s from being depressed, until when the signal-
man again pulls p' and P so as to lower the semaphore D, an incline g on the
upper edge of P acting on a stud projecting laterally from G, raises Gt and so leaves
free to be moved to the right and consequently leaves free to be depressed
by the wheel of a train entering the section in obedience to the lowered semaphore.
When the arrangements of the line are such that the semaphore D should not
be lowered to indicate "safety" unless permission is given from several places I
divide the rod C into several parts, the uppermost part e connected to the crank
arm d and having hinged to its lower end a part e' which has mounted on its lower
end a roller resting on the upper end of the next part which 18 fitted to slide
in guides and which itself rests on the upper end of C which is jointed to the
lever L
On the side of the signal post I fix an electromagnet H the armature lever h of
which bears against the part of the rod, which is usually kept in the position
shewn by a spring pressing it against a roller_h³ When from some controlling
place a current of electricity is transmitted to the magnet H, it by attracting its
armature pushes the part rode to the left, its roller escaping the end of the
part rod, so that when c³ is raised for the purpose of lowering the semaphore, it is
quite effective and remains so while the magnet H is energised When the
energising current is cut off the spring h¹ pushes c¹ to the right so that its roller &
again rests on the part rod and then the semaphore D can be lowered in the usual
way by the operating signalman drawing the pull and bar P
The spring roller ³ and magnet H may be arranged respectively to the other
hand that is to say h¹ on the right and h and H on the left so that the roller c² 18
normally kept by the spring off the part rod ³, the semaphore arm cannot then he
lowered by the usual pull unless the magnet 18 first energised, and thus it requires
two operators to conspire, the one by sending a current to energise the magnet, and
the other by moving the signal lever in order to give a "safety" signal
The blade s may have electrical contacts arranged in connection with it so as to
operate as a switch when a train passes over it closing or opening an electric circuit
for signalling or other purposes
When the blade is required by the conditions of the line to be in such a position
that it cannot be conveniently arranged to act, as described, directly on the
mechanism for disconnecting the bara P P', it may, on being depressed, make a
contact to transmit a current to an electromagnet in the box A which on heing
energised, attracts the armor and thereby effects disconnection of the
bars P P¹, in the same manner as it is effected by the depression of blade s. In like
manner an electric current transmitted otherwise than by the depression of the
blade s might energise the electromagnet and effect the disconnection
Having now particularly described and ascertained the nature of this
invention, and in what manner the same is to he performed, I declare that what
I claim is:
1. Making part of the pull for lowering a railway signal to consist of two bars

page_text: usually connected so as to operate together as one bar for lowering the signal,
and mounting by the side of a neighbouring rail a blade with connections such
that on its being depressed by the wheel of a passing train the two bars are
disconnected and the signal is left free to rise to danger" substantially as
described.
46
2. Making the vertical rod on the post of a railway signal in several parts which
have to act together in order to lower the signal, and fixing beside one of the rod
parts an electromagnet which, when energised by an electric curient from a distant
place either separates this part from the other parts and so renders the iod in-
effective in lowering the signal or connects this part to the other parts and so
renders the rod effective in lowering the signal substantially as described.
3 For operating as set forth in the preceding claims, apparatus substantially as
described with reference to the drawings
4 The modified apparatus wherein the disconnection of the bar referred to in
Claim 1 is effected by an electromagnet, substantially as described
Dated this 21at day of December 1898
ABEL & IMRAY,
Agents for the Applicant.
ABEL & IMRAY,
Agents for the Applicant.