Year: 1888

page_text: Date of Application, 10th Feb., 1888
Complete Specification Left, 8th Nov., 1888-
Complete Specification Accepted, 14th Dec., 1888
I, JAMES BALLANTYNE HANNAY, of Cove Castle, Loch Long, in the County of
Dumbarton, North Britain, Chemist, do hereby declare the nature of this Invention
to be as follows, that is to say :-
My said Invention has for its object by an improved, simple, and effective device,
to prevent the positions of semaphore signals such as are used upon railways, being
rendered inaccurate in consequence of variations in the length of the chains by means
of which the signals are worked.
In carrying out my Invention I lead the chain for working the signal to and over
a pulley to a weight which whilst sufficient to keep the chain stretched is overbalanced
by the weight on the lever at the signal post, and which latter weight is, ordinarily,
arranged to place the signal arm in its elevated or "danger" position when allowed to
act. For pulling the chain to cause the lowering of the signal arm a fork is provided
which is connected to the signalling hand lever, and which is made with long spring
prongs having claws at their ends for gripping the chain. The fork works between
guides, but the outer ends of the prongs are set outwards so as to be wider than the
space between the guides, and when the fork is drawn up by the hand lever, the ends
of the prongs are made to close the claws upon the chain in consequence of the set out
parts being drawn within the guides. With this arrangement the fork takes hold of
the stretched chain and draws it the same distance at all times. When the fork
is moved back again the spring prongs open and become clear of the chain, which is
then free to lengthen or shorten being however always kept stretched by the weight
at the end of it. Antifriction rollers may be fitted at the ends of the guides to act
on the set-ont parts of the prongs, and antifriction rollers or pins may also be suitably
placed to insure the opening of the prongs when the fork is moved back.
Dated this Ninth day at
1000

page_text: I, JAMES BALLANTYNE HANNAY, of Cove Castle, Loch Long, in the County of
Dumbarton, North Britain, Chemist, 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, that is to say :-
My said Invention has for its object by an improved, simple, and effective device,
to prevent the positions of semaphore signals such as are used upon railways, being
rendered inaccurate in consequence of variations in the length of the chains or
connections by means of which the signals are worked.
In carrying out my Invention the chain for working the signal is led over a pulley
and kept stretched by means of a weight attached to one of its ends its other end
being connected to the ordinary weighted lever at the signal post. The chain is
pulled to lower the signal by being caught by the prongs of a spring fork working
between guides and attached to the signalling hand lever. Antifriction rollers are
provided to insure the closing and opening of the prongs when the spring fork is
moved by the hand lever.
A convenient and simple modification of the improved apparatus is shown on an
accompanying sheet of explanatory drawings on which figures, 1, and 2, are respec-
tively, side and front elevations showing my improvements; and figure, ô, is a side
elevation showing the signal post and semaphore. In these drawings the same
reference numerals are used to mark the same or like parts wherever they are
repeated.
According to my Invention the chain, 4, for working the signal arm, 5, passes
under a guide pulley, 6, and its end is led up to and over a pulley, 7, carried in
bearings in a bracket, 8, fixed to a beam, 9, which may form part of the pointsman's
cabin. A weight, 10, is attached to this end of the chain, 4, which whilst sufficient
to keep the chain, 4, stretched, is overbalanced by the weight, 11, on the lever, 12, at
the signal post, 13, and which weighted lever, 11, 12, is connected as usual through a
rod, 14, to the signal arm, 5, so as to place it in its elevated or "danger" position
when allowed to act. For pulling the chain, 4, to cause the lowering of the signal
arm, 5, a fork, 15, is provided which is connected by a link, 16, to the signalling hand
lever, 17, and which is made with long spring prongs having claws, 18, at their ends
for gripping the chain, 4. The fork, 15, works between guides, 19, formed on
a bracket, 20, fixed to the beam, 9, but the outer ends of the prongs are set outwards
so as to be wider than the space between the guides, 19, and when the fork, 15, is
drawn up by the hand lever, 17, the ends of the prongs are made to close the claws, 18,
upon the chain, 4, in consequence of the set-out parts being drawn within the
guides, 19. With this arrangement the fork, 15, takes hold of the stretched chain, 4,
and draws it the same distance at all times. When the fork, 15, is moved back again
the spring prongs open and become clear of the chain, 4, which is then free to
lengthen or shorten being however always kept stretched by the weight, 10, at the

page_text: end of it. Antifriction rollers, 21, are fitted at the lower ends of the guides, 19, to
act on the set-out parts of the prongs when these are drawn up, and antifriction
rollers, 22, are also suitably carried by the bracket, 20, so as to act on the inner sides
of the prongs and insure their opening when the fork, 15, is lowered.
Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
In semaphore signalling apparatus the application of a device arranged to grip the
chain or connection when operated to move the semaphore such device leaving the
chain or connection free at other times to be stretched by a weight substantially as
hereinbefore described.
1000
EDMUND HUNT,
Applicant's Agent.