IMPROVEMENTS IN RAILWAY SIGNALS
Year: 1873

page_text: LETTERS PATENT to Ebenezer Entwistle, of Blackburn, in the County
of Lancaster, for the Invention of "IMPROVEMENTS IN RAILWAY
SIGNALS."
Sealed the 16th December 1873, and dated the 2nd July 1873.
PROVISIONAL SPECIFICATION left by the said Ebenezer Entwistle at
the Office of the Commissioners of Patents, with his Petition, on
the 2nd July 1878.
I, EBENEZER ENTWISTLE, of Blackburn, in the County of Lancaster,
do hereby declare the nature of the said Invention for "IMPROVEMENTS IN
RAILWAY SIGNALS," to be as follows:-
My Invention relates to and consists of certain improvements in
railway signals, apparatus for which Letters Patent were granted to me
on the 12th day of December 1871, No. 3355.
Instead of the bow lever marked b, b, in the Drawings of the before-
mentioned Patent being linked to crank ƒ by link h, I connect it by a
stud to a portion of a flanged pulley working eccentrically and on a

page_text: suitable centre; the upper side of such pulley acts under the aforesaid
bow lever; such bow lever likewise acts upon the eccentric when pressed
by the flange of the wheel.
The aforesaid portion of a flanged pulley is connected to the square of
a shaft secured to the sleepers or any other equivalent; and to the said !
shaft is connected a lever or levers which are connected to a counterpoise
lover or levers with adjustable weights on them by leg lever, rods, or
other equivalents, and the said counterpoise lever or levers are again
connected by means of wire, chains, or other equivalent to a pulley or
pullies or any other mechanical equivalent, to which is attached an
adjustable catch or catches which act upon a ratchet wheel or wheels,
for the meeting of expansion and contraction of the wire, and putting on
the signals in front, which are three of the main objects of this my
Invention, and leaving a signal on behind, and the catch or catches
liberate themselves when they have done the work required.
I connect to the present signal arms and their connections, the said
pulley or pullies or their equivalents, by means of wire, chain, or other
equivalent, or I may connect the said signal arm and its connections to
the said counterpoise, connecting wire, chain, or equivalent, for the
purpose of raising and falling the signal arm. The said ratchet wheel
or wheels are fitted to a square boss, and on the said boss is fixed a
grooved pulley with notches in the bottom of the groove to prevent the
chain from slipping. The said chain is connected at one end to a weight
or weights sufficient to draw the wire or its equivalent, and the other
end of the said chain or equivalent is connected to one end of the said
wire or equivalent, and the other end of the said wire or equivalent is
connected to weights equal to the before-mentioned weights, and hangs
over another notched groove pulley similar to the one before mentioned.
I can also work the said ratchet wheel and its connections by means of a
revolving weight running round a semicircle or quadrant line.
I place on the counterpoise lever a compensating catch, or catch and
catch wheel to meet the variation in the flanges of the wheels acting on
my bow lever...