IMPROVEMENTS IN RAILWAY SIGNALLING APPARATUS
Year: 1877

page_text: LETTERS PATENT to John Cariss, of the City of York, in the County of
York, Engineer, for the Invention of "IMPROVEMENTS IN RAILWAY SIGNALLING
APPARATUS."
PROVISIONAL SPECIFICATION left by the said John Cariss at the Office
of the Commissioners of Patents on the 31st December 1877.
JOHN CARISS, of the City of York, in the County of York, Engineer.
PROVEMENTS IN RAILWAY SIGNALLING APPARATUS."
"IM-
This Invention, having reference to certain improvements in railway signalling
apparatus, relates more particularly to improved signal wire compensating appa-
ratus, especially designed to automatically allow for the contraction and expansion
in the length of signal wires upon a change of weather or of temperature taking
place; the improved apparatus being equally applicable to the ordinary system of
working signals, and to the improved method of working signals described in the
Specification of certain Letters Patent granted to me on the 2nd day of February
1876, No. 413.
My improved apparatus consists of two standards carrying an axle, on which
revolve a double grooved pulley or wheel with a ratchet toothed rim, or made fast
to a ratchet wheel, and a single grooved pulley or wheel. Between these pulleys
is a semicircular frame bolted to the same foundation as the standards, and slotted
throughout its semicircular portion, which is concentric with the pulleys, the slot
being at one extremity formed excentric to the pulleys. The single grooved
pulley has a lug, which projects under the semicircular frame, and at its end carries
a pivotted pawl fitted with a friction roller which engages in the semicircular slot,
and when in the concentric portion keeps the pawl in action with the ratchet
wheel, but when in the excentric portion takes the pawl out of action therewith.
The signal wire is fastened by a short length of chain to one of the grooves of the
double pulley, to the other groove of which is fastened a wire or chain carrying a
taking-up weight, and to the single grooved pulley is fastened a chain, which

page_text: passes round it, and being guided by pulleys in suitable positions is fastened at its
extremities to the opposite tails or ends of an ordinary I shaped signal lever in the
cabin.
This improved apparatus is intended to be placed in or as near to the signal
cabin or box as possible, and it is free to act upon the signal wire for the purposes
of the Invention at the time the signal arm stands at "danger," the lever in the
cabin being in its normal or forward position, and the roller of the pawl in the
excentric portion of its semicircular slot. To signal "all right" the signalman in
the cabin reverses the position of the said lever, which by means of its chain
revolves the single grooved pulley, and brings the roller of the pawl it carries into
the concentric portion of the semicircular slot and the pawl into gear with the
ratchet on the double grooved pulley wheel, which is thus partially revolved,
raising the weight and slackening the signal wire, which allows of the weight at
the signal post effecting the lowering of the signal arm to the position of "all
right," as described in my said former Specification. The replacing of the lever
in the cabin in its normal position pulls the signal arm to " danger," throws the
roller of the pawl into the excentric portion of its slot, and out of gear with the
ratchet wheel, freeing the weight, which then causes the double grooved pulley to
partially revolve or turn back and take up any slack of the signal wire or allow
for any contraction thereof.
In using this improved wire compensator with the ordinary method of working
signal arms the signal wire is connected to the said 1 lever so as to work in the
contrary way.
The taking-up weight, according to my improved method of working signal arms,
may be as heavy as convenient, but with the ordinary method it should be made
lighter than the danger weight at the signal post.
The parts are so combined and disposed that should any wire or chain break
there will still be a constant tendency to bring and keep the signal arm at
'danger," thus blocking the road in the event of any mishap to the signalling appa-
ratus till all is again put right.
"

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Cariss in the Great Seal Patent Office on the 29th June
1878.
JOHN CARISS, of the City of York, in the County of York, Engineer. "IM-
PROVEMENTS IN RAILWAY SIGNALLING APPARATUS."
This Invention, having reference to certain improvements in railway signalling
apparatus, relates more particularly to improved signal wire compensating appa-
ratus, specially designed to automatically allow for the contraction and expansion
in the length of signal wires upon a change of weather or of temperature taking
place; the improved apparatus being equally applicable to the ordinary system of
working signals, and to the improved method of working signals described in the
Specification of certain Letters Patent granted to me on the 2nd day of February
1876, No. 413.
My improved compensating apparatus is illustrated on the accompanying
Drawings in Figures 1 and 2, which respectively represent a side elevation and an
end elevation.
The apparatus is constructed with two side standards 1 carrying an axle or
shaft 2 secured at each end by nuts 3, and on which are loosely mounted a double
grooved pulley or wheel 4 formed with a ratchet toothed rim 5, or made fast to a
ratchet wheel and a single grooved pulley or wheel 6. Between these pulleys, and
standing above them, is a semicircular frame 7 bolted to the same foundation as
the standards 1 are, and slotted throughout its semicircular portion, which is con-
centric with the pulleys 4, 6, the slot 8 being at one extremity formed excentric to
the pulleys, as shown at 9. The pulley has a lug 10, which projects under the
frame 7, and at its end carries a pawl 11 centred on a stud or bolt 12 and secured
by nuts 13, and provided with a friction roller 14 centred on a stud or bolt 25, and
secured by a nut 26, and which travels in the slot 8, and when in the concentric
portion thereof keeps the pawl 11 in action with the ratchet wheel 5, but when in
the excentric portion thereof takes the pawl out of action therewith, as shown most
clearly in Figure 1. The signal wire is fastened by a short length of chain 15 to
the groove 16 of the pulley 4, to the other groove 17 of which is fastened a wire or
chain 18 carrying a taking-up weight 19, and to the groove of the pulley 6 is
fastened a chain 20 which passes around it, and being guided by pulleys in suitable
positions is fastened at suitable distances to the opposite tails or ends of the
ordinary shaped signal lever in the cabin, or the chain 20 may be single-ended
and connected to one end only of the lever. The chains 15, 18, and 20, which all
pass either partly or entirely around their respective grooves of the pulleys 4, 6,
are respectively connected or fastened thereto at about the points 22, 23,
and 24.
«
The above described improved compensating apparatus is intended to be placed
in or as near to the signal cabin or box as possible, and it is free to act upon the
signal wire for the purposes of the Invention at the time the signal arm stands at
danger," the lever in the cabin being then in its normal or forward position, and
the roller 14 of the pawl 11 in the excentric portion 9 of the slot 8, so as to ungear
the pawl from the ratchet wheel 5. In signalling "all right" the signalman in the
cabin reverses the position of the said ✓ lever, which by means of its chain 20
revolves the pulley 6 and brings the roller 14 into the concentric portion of the
slot and the pawl 11 into gear with the ratchet wheel 5 on the pulley 4, which is
thus partially revolved, raising the weight and slackening the signal wire, which
allows of the weight at the signal post effecting the lowering of the signal arm to
the position of "all right," as described in my said former Specification. The
replacing of the lever in the cabin in its normal position pulls the signal arm to
danger," and again throws the roller 14 into the excentric portion 9 of the slot 8
and the pawl 11 out of gear with the ratchet wheel 5, thus freeing the weight,
"

page_text: which then causes the pulley 4 to partially revolve to take up any slack or allow
for any contraction of the signal wire.
In using the above described improved compensating apparatus with the
ordinary method of working signal arms the signal wire and weight at the com-
pensator are connected to work the reverse way.
The taking-up weight, according to my above referred to improved method of
working signal arms, may be as heavy as convenient, but with the ordinary method
it should be made lighter than the danger weight at the signal post.
The parts of the apparatus are so combined and disposed that should any wire
or chain break there will still be a constant tendency to bring and keep the signal
arm at "danger," thus blocking the road in the event of any mishap to the appa-
ratus till all is again put right.
Having now described the nature and object of my said Invention, together with
the manner in which the same is to be or may be performed or carried into practical
effect, I would remark in conclusion that I claim as my Invention, the new and
peculiar construction of signal wire compensating apparatus, with the above
described combination of pulleys and ratchet wheel mounted loosely upon an axle
or shaft carried by side standards, or with any modification of such combination,
and with a semicircular slotted frame, or any modification thereof or mere equi-
valent therefor formed with concentric and excentric portions for the purpose of
actuating a pivotted pawl carried by one of such pulleys, and allowing such appa-
ratus to act upon the signal wire and take up any slackness or allow for any con-
traction thereof at the time the signal arm stands at "danger," substantially as
above described, and as illustrated on the accompanying Drawings.
In witness whereof, I, the said John Cariss, have hereunto set my hand and
seal, this Twenty-sixth day of June, in the year of our Lord One
thousand eight hundred and seventy-eight.
TOTAL ATTOO
JOHN CARISS. (L.S.)