IMPROVEMENTS IN APPARATUS FOR WORKING RAILWAY SIGNALS
Year: 1882

page_text: LETTERS PATENT to John Harrisson of Well Street Hackney in the County
of Middlesex, for an invention of IMPROVEMENTS IN APPARATUS FOR
"
"
WORKING RAILWAY SIGNALS."
PROVISIONAL SPECIFICATION left by the said John Harrisson at the Office,
of the Commissioners of Patents on the 6th April 1882.
JOHN HARRISSON of Well Street Hackney in the County of Middlesex
'IMPROVEMENTS IN APPARATUS FOR WORKING RAILWAY SIGNALS,'
"
This Invention has for its object improvements in apparatus for working
railway signals.
It is frequently desirable to employ automatic signals such that as soon as a
train passes the signal shall automatically be set to danger.
Now my Invention admits of such automatic signals being used in connection
with interlocking apparatus such as is now in common use to prevent the signals
being at variance with the points. I make no change in respect to the signal
levers and the interlocking apparatus; but for any signal which it is desired to
render automatic I provide a latch in the course of the wire or connection passing
from the lever to the signal post. A weight is as usual provided which carries
the signal to danger except when it is drawn down by the wire or connection and
another weight to keep the wire or connection in tension. Near the latch a
treddle is provided upon the line of railway and the office of this treddle is to lift
the latch and disengage the signal from the signal lever when a train passes the
treddle. The signal is at once raised by the weight to the danger position, and
draws back with it one half or division of the latch whilst the other half or
division in connection with the wire which passes to the signal lever remains
unmoved until the signalman sets back the signal lever in ordinary course.
When the signal lever is put back this latter part of the latch is by the weight
attached to the end of the wire drawn into position for the two parts of the latch
to again engage with one another and the signalman may then when he requires
to do so draw down the signal in the usual way. Thus my apparatus in no way
interferes with the working of the signals and the interlocking gear but it
prevents the signal man retaining the signal at safety after the train has passed it.
Electrical contact apparatus may be provided in connection with the treadle or
lifting bar to announce the arrival of a train.
.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said John Harrisson in the Great Seal Patent Office on the 6th October
1882.
JOHN HARRISSON of Well Street Hackney in the County of Middlesex
"IMPROVEMENTS IN APPARATUS FOR WORKING RAILWAY SIGNALS."
This Invention has for its object improvements in apparatus for working
railway signals.
It is frequently desirable to employ automatic signals such that as soon as a
train passes the signal shall automatically be set to danger.
.
Now my invention admits of such automatic signals being used in connection
with interlocking apparatus such as is now in common use to prevent the signals
being at variance with the points. I make no change in respect to the signal
levers and the interlocking apparatus; but for any signal which it is desired to
render automatic I provide a latch in the course of the wire or connection passing
from the lever to the signal post. A weight is as usual provided which carries
the signal to danger except when it is drawn down by the wire or connection
and another weight to keep the wire or connection in tension. Near the latch a
treadle is provided upon the line of railway and the office of this treadle is to lift
the latch and disengage the signal from the signal lever when a train passes the
treadle. The signal is at once raised by the weight to the danger position and
draws back with it one half a division of the latch whilst the other half or division
in connection with the wire which passes to the signal lever remains unmoved
until the signalman, sets back the signal lever in ordinary course..
When the signal lever is put back this latter part of the latch is by the weight
attached to the end of the wire drawn into position for the two parts of the
latch to again engage with one another and the signalman may then when he
requires to do so draw down the signal in the usual way. Thus my apparatus in
no way interferes with the working of the signals and the interlocking gear but
it prevents the signalman retaining the signal at safety after the train has
passed it.
Electrical contact apparatus may be provided in connection with the treadle or
lifting bar to announce the arrival of a train.
In order that my said invention may be most fully understood and readily
carried into effect I will proceed-to describe the Drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a side elevation of the apparatus as I prefer to arrange it; the
apparatus is here shown as it appears when the signal has been taken off by means
of the signal lever in the cabin where there is the ordinary interlocking apparatus
to prevent the signal being lowered until the points and other signals have been
suitably set.
Figure 2 is also a side view of the apparatus but with the parts in the position
they occupy when the signal has been set free automatically by a train passing
the signal, and has returned, so that it is now on against a following train.
Figure 3 is again a side view with the parts in a third position, viz. with the
signal lever in the cabin also in the "danger" position; that is to say, in the
position in which the signal being "on" the levers interlocked with the signal
lever are free.
Figure 4 is a plan of some of the parts.
a a are standards. b is a bar held by the standards and capable of sliding

page_text: longitudinally. c is a chain or other connection passing from the bar b to the signal
lever d. The lever d is in the signalman's cabin where there is the usual inter-
locking gear to prevent the lever being used to take off the signal unless the
switches and other signals are properly placed. e is a chain or other connection
passing from the other end of the sliding bar b to a weight which takes the bar
forward when the lever & permits, f is a latch, it is connected with the bar b, by
a pin at f passing through a slot 6 in the bar. At its other end at the latch is
capable, of engaging with the shoulder 62 upon the bar b, g is a forked link held by
one of the standards a and capable of sliding longitudinally; it is connected at
one end with the pin f¹ of the latch and at the other end with a chain or other
connection h passing to the arm of the weighted lever k which is upon the
signal post. The lever is connected in the usual way with the signal arm; its
weight raises the signal arm or puts the signal ou and it is taken off by the pull
of the chain or connection h. I is a tripping lever it is pivotted to one of the
standards at . and by preference it is arranged nearly to balance about the pivot.
The outer end of this lever is acted upon in any convenient way by a treadle by
the side of the rail which a train, in passing depresses. The treadle lever can be
fixed upon an axis m upon which there is also a lever arm m¹. The depression
of the treadle raises the arm m¹ and the end of the tripping lever l.
Now when the signal is off the nose of the latch f rests upon the tripping lever
so that on this lever being raised the latch is disengaged from the shoulder 62 of
the bar b. The latch is then drawn forward by the weight and the signal is
automatically put on against a following train. The signalman can take the
signal off by first putting the lever d to the danger position, when the latch again
engages with the bar b at b and thus on the return of the lever it operates the
signal in the usual way.
In place of a sliding bar ba bent bar or are mounted cn an axis may, be
substituted.
It is obvious that my invention may be used with disc and other forms of signals,
as well as with semaphore arins.
Having thus described the nature of my said invention and the manner of
performing the same I would have it understood that I do not confine myself to
the forms and detail of the parts represented in the Drawings. But what I claim
as my improvements in apparatus for working railway signals is the interposition
between a signal lever controlled by interlocking apparatus and its signals; of a
latch which is disengaged by a passing train (causing the signal to be automatically
put on against a following train whilst the signal lever remains in the off position)
and which latch reengages when the signal lever is moved back by the signalman
on the "on" or "danger" position of the signal substantially as described.
In witness whereof I the said John Harrisson have hereunto set my hand
and seal this twenty sixth day of September in the year of our Lord One
thousand eight hundred and eighty two.
JOHN HARRISSON. (L.S.)