Improved Compensating Apparatus for Signal Wires.
Year: 1898

page_text: COMPLETE SPECIFICATION.
Improved Compensating Apparatus for Signal Wires.
I, ELI WILLIAM PERRETT, of 23, Llantwit Street, Cathays, Cardiff, Railway
Signal Superintendent, 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: →
This invention consists in apparatus for maintaining at an approximately even
tension the wires of railway and like signals. Such wires, as is well known, are
liable to variation in length by reason of expansion and contradtion due to
temperature and, in addition to this, they are liable to become extended through
stretching due to straining in use.
Now the compensating apparatus which constitutes this invention prevents the
wires from becoming unduly tight and also takes up slack, so that the wires are
kept at an approximately even tension which facilitates the working of the signals
which they are employed to operate.
Referring to the accompanying drawing, the Figure shown thereon represents
in elevation or face view my improved apparatus for maintaining signal wires at
an approximately even tension.
+
The apparatus consists of a crosshead a capable of swinging on a pivot pin or
stud projecting outwards from a plate ¹ secured to a post or other suitable
support. The back of the crosshead a bears lightly against the upper ledige of
a bracket 6 fixed to the post which ledge projects out as an angle iron there-
from at a suitable distance. The post or support is situated at a given point,
preferably approximately half-way, between the signal to which the apparatus
appertains and the hand lever by which the signal is operated. Capable of moving
about the pin d fixed on the crosshead is a compensating cranked lever e which
is on that side of the apparatus which is nearest the hand lever by which the
signal to which the apparatus appertains is operated; on that side of the
apparatus which is nearest the signal is pivotted on the pin f, fixed to the cross-
head, a cranked lever g. The limb e¹ of the lever e is connected to the limb g¹
of the lever g by a pair of links h, one at front and the other behind. The
links are capable of moving about the pivot pins and g by which the links
are connected to the levers. The lovers é and 9, links and pins and gª, are
clear of the crosshead a, that is to say, a space intervenes between them and the
front face of the crosshead over which they work freely. Made in one piece with
the lever e, or rigidly attached thereto and consequently moving therewith, is
an arm carrying an adjustable counterweight j. Towards its lower end the
lever 9 carries a pulley over the spindle of which is passed the shackle / of
the wire m which extends thence to the signal. The lever g is forked at its lower
end to form a bracket providing bearings for the spindle at each end thereof.
Projecting downward from the crosshead a is a leg n carrying a stop o which
serves as a check to prevent disarrangement of the mechanism in event of heavy
objects being placed on the wires or in event of their becoming otherwise unduly
depressed. The wire p, which is connected to the signal-operating hand-lever.
is connected by a shackle p¹, which may be a swivel shackle, to a draught wheel g

page_text: partly around which is passed a chain r one end of which is connected to the
lever e.
The chain is conducted from the draught wheel to the pulley & and,
after having been carried partly around it, is connected to the leg n of the
crosshead a..
.
When the apparatus is put into place with the wires in and P strained to a
suitable working degree of tension, the counterweight is adjusted on the arm i
so as to keep the lever e away from the stop o to a given extent at the said degree
of tension. *In event of contraction of the wires m and p, the counterweighted
arm i is raised by the opening action of the leverse and g and thus the tension
is maintained. When expansion or extension of the wires m and p occurs, the
levers e and 9 close in and thus the counterweighted arm i is caused to drop and
the slack is taken up. When only one wire either m or p-contracts, the
levers e and g swing on the stud 6 to a proportionate extent and equalize the
tension. When one wire contracts and the other expands, the leverse and
are not relatively shifted but the apparatus swings and thus equalizes the tension.
When both wires m and p expand, the levers e and g close in and the tension is
thus maintained. When only one wire either m or p-expands, the lovers e
and g close to a proportionate extent and the apparatus swings on the stud b and
produces equal tension.
The compensating action of the apparatus is independent of the positions to
which it is swung in operating the signal. In the drawing the apparatus is
thown in the position it occupies when the signal stands at danger. When the
signal is operated to indicate "line clear," the crosshead is swung towards the
operating hand lever with the movement of the wire as operated from the hand
lever.
In event of severance of wire or fracture of other parts of the apparatus, the
signal goes to danger in accordance with requirement.
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:-
1. For maintaining signal wires at an approximately even tension, compensa-
ting apparatus arranged and operating substantially as hereinbefore described.
2. Compensating apparatus for maintaining signal wires at an approximately
even tension; said apparatus consisting of a swinging crosshead such as a with
fixed leg and stop plate o, levers e, y, e¹ and y, pivotally connected to the
crosshead and linked together by links such as h, an arm such as i with adjustable
counterweight, a running chain such as passed round pulleys such as kand 9,
of which is connected to the wire extending from the apparatus to the signal
and to the wire extending from the apparatus to the signal-operating hand-
lever the parts being constructed, arranged and operated substantially as
hereinabove described with reference to the accompanying drawing.
Dated this 14th day of November 1898.