IMPROVEMENTS IN APPARATUS FOR COMPENSATING FOR VARIATIONS IN THE LENGTH OF WIRES USED FOR WORKING RAILWAY AND OTHER SIGNALS."
Year: 1879

page_text: LETTERS PATENT to Edward Paget Gadsby, of Rainhill, in the County of
Lancaster, M.A., C.E., for the Invention of "IMPROVEMENTS IN APPARATUS FOR
COMPENSATING FOR VARIATIONS IN THE LENGTH OF WIRES USED FOR WORKING
RAILWAY AND OTHER SIGNALS."
ft
PROVISIONAL SPECIFICATION left by the said Edward Paget Gadsby at the
Office of the Commissioners of Patents on the 14th August 1879.
EDWARD PAGET GADSBY, of Rainbill, in the County of Lancaster, M.A., C.E.
IMPROVEMENTS IN APPARATUS FOR COMPENSATING FOR VARIATIONS IN THE
LENGTH OF WIRES USED FOR WORKING RAILWAY AND OTHER SIGNALS."
This Invention has for its object improvements in apparatus for compensating for
variations in the length of wires used for working railway and other signals.
For this purpose the end of the wire is connected to a chain led under a pulley at
the foot of the signal post, and then upwards and over a pulley suspended from the
weighted lever to which the chain is usually attached. The chain is then carried
downwards and coupled to a piston that works somewhat loosely in a cylinder
containing liquid.
The weight of the piston is not sufficient to allow it to raise the weighted arm of
the lever by which the signal is coupled, but whenever a strain is placed upon the
signal wire by the pulling over of the hand signal lever the weighted lever in con-
nection with the signal will be raised and the signal will be dropped, as the piston
fitting within its cylinder, and being immersed in the liquid, cannot be raised quickly
therein.
Any suitable arrangement may be adopted for preventing the weight in the lever
arm from then overcoming the weight of the piston and further raising the piston
in the cylinder, which would have the effect of allowing the weighted lever arm to
gradually drop and again raise the signal to danger. For example, the weighted
lever arm in connection with the signal might, when raised, be brought towards a
vertical position, so that the weight on the arm would not then be able to overcome
D

page_text: the weight of the piston; or the pulley suspended from the weighted lever, and
over which the chain passes, might be notched on its circumference, and when drawn
downwards by the signal wire be brought against a stop or catch, which would
engage with one of the notches in the periphery of the pulley and prevent it from
turning, or the pulley might simply be brought down against a friction block to
prevent its turning.
There would then be no tendency to lift the piston, and the weighted lever in
connection with the signal would be retained in its raised position until, by the
movement of the hand lever by which the signal wire is worked, the wire is again
slackened. The weighted lever in connection with the signal would then at once
drop and move the signal to danger. When the signal is at danger the weight of
the piston at the end of the wire would keep a uniform strain upon the wire,
whether its length were somewhat increased or diminished from expansion or con-
traction, whether arising from variations of temperature or from other causes, as the
piston being always free to move slowly in the cylinder, its weight would always
tend to keep a uniform tension on the wire at the times when the weighted lever
of the signal is not held up by it.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Paget Gadsby in the Great Seal Patent Office on the 13th
February 1880.
86
EDWARD PAGET GADSBY, of Rainhill, in the County of Lancaster, M.A., C.E.
IMPROVEMENTS IN APPARATUS FOR COMPENSATING FOR VARIATIONS IN THE
LENGTH OF WIRES USED FOR WORKING RAILWAY AND OTHER SIGNALS."
This Invention has for its object improvements in apparatus for compensating for
variations in the length of wires used for working railway and other signals.
For this purpose, in place of simply connecting the end of the signal wire to a
chain led under a pulley at the foot of the signal post, and then attaching it to a
weighted lever to which the signal arm is coupled, as is for the most part the case
in railway signal apparatus now used, I, in addition, connect the chain to a weighted
piston that works somewhat loosely up and down in a cylinder containing liquid.
The weight of the piston is not sufficient to allow it to raise the weighted arm of
the lever to which the signal is coupled, but whenever a strain is placed upon the
signal wire by the pulling over of the hand signal lever the weighted lever in con-
nection with the signal will be raised and the signal will be dropped, as the piston
fitting within the cylinder, and being immersed in the liquid contained therein,
cannot be raised quickly.
Any suitable arrangement may be adopted for preventing the weight on the lever
arm from then overcoming the weight of the piston and further raising the piston
in the cylinder, which would have the effect of allowing the weighted lever arm to
gradually drop and again raise the signal to danger.
When the signal is at danger the weight of the piston would keep a uniform
strain upon the wire, whether its length were somewhat increased or diminished
from expansion or contraction, whether arising from variations of temperature or
from other causes, as the piston, being always free to move slowly in the cylinder,
its weight would always tend to keep a uniform tension on the wire at the times
when the weighted lever is not held up by it. It is better that the cylinder with
its weighted piston should be close up to the signal post, but this is not essential.
In the Drawings hereunto annexed I have shewn two arrangements of signal
apparatus.constructed on the above principle.
In Figure 1, A is the signal post; B, the ordinary signal arm, but other forms of
signal may be used; C, the weighted lever; D, a chain attached at one end to the
lever C and at the other to the end of the signal wire E, which passes away to the
hand lever used for working the signal as usual. The chain passes from the weighted
lever C under a pulley G and over a pulley H. The spindle of the pulley H is
carried by a bracket fixed to the signal post, whilst the spindle of the pulley G is
carried by a frame attached by a chain or otherwise to a piston which fits within
the cylinder K; this cylinder is fixed in position at the foot of the post as shown.
As before stated, the piston is made so that liquid contained in the cylinder can
only pass slowly from one side of the piston to the other. The piston is also
weighted to the extent requisite for maintaining any desired strain upon the signal
wire.
It will thus be seen that when the signal wire is set slack and the weighted lever
C allowed to drop into the position shewn in the Drawing, so as to raise the signal
to danger, the weighted piston will, if the wire is still slack, descend and tighten up
the wire to the extent required. If the weight of the piston were then sufficient to
raise or partially raise the weighted lever C when partly counterbalanced by the
weight of the signal arm it may be prevented from doing so by the employment of
a small catch 0; in this case the weighted lever C is not coupled directly to the
rod P which passes up to the signal arm, but this rod is connected to one arm of a
lever upon which the weighted arm of the lever C rests, and the catch O drops

page_text: behind the other arm of the lever Q, as shewn. Thus, when the signal has been set
at danger, it is held there by the catch O, and does not tend to lift the lever C. The
weight of the piston must not be sufficient to allow of its then lifting the lever C.
When the hand signal lever is moved over to pull on the signal wire and lower the
signal the lever C is raised, and nearly at the end of its movement releases the catch
O and allows the signal to drop; the lever C is for this purpose coupled to the catch
O by links R, as shewn.
If the weight of the lever C when thus raised is sufficient to overcome the weight
of and raise the piston it may be prevented from doing so by employing a catch or
bolt N as shewn. In this case the chain which connects the spindle of the pulley G
with the piston of the cylinder K is not passed directly from one to the other, but
is passed one or more times around a pulley L, on the axis of which is a notched or
toothed wheel M. The catch or bolt N can drop into any one or other of the teeth
or notches of the wheel M, and is connected by a cord with the tail end of the
weighted lever C. When the weighted arm of this lever is raised so as to drop the
signal to "all right" the bolt N drops and locks the wheel M, thereby preventing
the pulley G from being drawn upwards.
Another way for securing that the weight of the lever C when raised so as to lower
the signal shall not be able to raise the piston, and so allow the signal again to rise
to danger, is shewn at Figure 2.
In this case the weighted arm of the lever C is, when raised, brought towards a
vertical position, whilst the other arm of the lever C which is acted upon by the
weighted piston is brought towards a horizontal position.
Having thus described the nature of my Invention, and the manner of performing
the same, I would have it understood that I claim,―
First. The employment of a weighted piston working in a cylinder containing
liquid for keeping a uniform tension on the signal wires of railway and other signal
wires, substantially as described.
Second. The combinations of apparatus, substantially as herein before described,
for compensating for variations in the length of wires use for working railway and
other signals.
In witness whereof, I, the said Edward Paget Gadsby, have hereunto set my
hand and seal, this Tenth day of February, in the year of our Lord One
thousand eight hundred and eighty.