IMPROVEMENTS IN APPARATUS FOR SIGNALLING ON RAILWAYS
Year: 1871

page_text: PROVISIONAL SPECIFICATION left by George Daws at the Office of
the Commissioners of Patents, with his Petition, on the 21st March
1871.
I, GEORGE DAWs, of Penge, in the County of Surrcy, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN APPARATUS FOR
SIGNALLING ON RAILWAYS," to be as follows:-
My improvements refer to signals where wires, chains, or rods are
used for effecting communication between the signal station and signal,
and it is designed for compensating or counteracting the contraction and
expansion of the said wires, chains, or rods whereby the full throw is at
all times insured to the signal, thereby rendering tightening scrows and
other appliances heretofore used for the purpose unnecessary.
The Invention consists in communicating motion to the signal, as
hereafter described, as it were indirectly, instead of giving it a direct pull
as is generally done. I pass the wire or chain in connection with the
wire, chain, or rod from the signal station over a pulley or under one
and over another pulley, at say three or four feet from the ground, and
connect a weight thereto so that the pull given to the wire, chain, or rod

page_text: .
from the signal station acts directly on the weight; another chain or
wire connects the weight and the signal lever. The signal when in its
normal position is at "danger" and the weight then always hangs and
keeps the wire, chain, or rod between the weight and the signal station
stretched or taut, by pulling the wire, chain, or rod at the station the
weight is raised and the signal falls to "clear," although only described
to work at “ danger" and "clear," yet of course the same arrangement
applies for "danger" and "caution."
According to another arrangement I pass the wire or chain over and
under guide pulleys and suspend a weight thereon so that the weight
has always a tendency to pull the chain, wire, or rod tight and to take
up any slack there may be. I attach a small “ running" pulley to the
weight, under which pulley the wire or chain passes, and which act as
a guide thereto, and I place a pin on the signal side of the wire or chain,
which when the wire or chain is pulled from the signal station stops
or acts against the pulley and forms a stop so that the wire or chain
may not be pulled through the pulley but act on the signal. If the
wire, chain, or rod breaks the signal in all cases goes to danger.
Provision is made for the breaking of the wire or chain between the
lever and the pulley by placing another and separate chain between the
lever and weight so that if one chain breaks the other may hold.
Provision is also made for the breaking of the distance wire, chain, or
rod by placing another pin on the wire or in the chain, so that should
the latter break it may not run through the suspending pulley, the pin
acting as a stop and preventing the weight from releasing itself from
the wire or chain. A ledge or shelf is placed below the weight to receive
it in the event of the wire or chain breaking, the loose or auxiliary chain
then acts on the signal lever and throws the signal to " danger," but
because the weight rests on the shelf this auxiliary chain has no moro
strain on it than is just sufficient to raise the signal. Sometimes when
the distance is such that a very heavy weight would be required to
accomplish the object before named I lead the distance wire or chain
round a guide pulley or pulleys and secure the end thereof to the upper-
most pulley on the signal post. To the same pulley or to another pulley
in one with or fixed to it I fix the end of the wire or chain leading (up
to the signal, and to the spindle on which the pulley is fixed, (or if loose
on the spindle) to the boss of the pulley, I fix a lever carrying a quadrant

page_text: adjustable thereon, from the upper end of which I suspend a weight,
which always having a tendency to fall keeps the wire taut, works the
signal in a similar manner to the arrangement first described, the
difference being that in this case the weight is gained by lever and
5 quadrant whereas in the other it is obtained by a dead weight.