IMPROVEMENTS IN APPARATUS FOR WORKING RAILWAY SIGNALS
Year: 1871

page_text: LETTERS PATENT to James John Frederick Stevens, of Darlington
Works, Southwark, in the County of Surrey, Railway Signal
Manufacturer, for the Invention of “IMPROVEMENTS IN APPARATUS
FOR WORKING RAILWAY SIGNALS."
Scaled the 19th December 1871, and dated the 13th October 1871.
PROVISIONAL SPECIFICATION left by the said James John Frederick
Stevens at the Office of the Commissioners of Patents, with his
Petition, on the 13th October 1871.
I, JAMES JOHN FREDERICK STEVENS, of Darlington Works, Southwark,
in the County of Surrey, Railway Signal Manufacturer, do hereby declare
the nature of the said Invention for "IMPROVEMENTS IN APPARATUS FOR
WORKING RAILWAY SIGNALS," to be as follows :-
✓ The object of my Invention is so to construct apparatus for working
railway signals that a signal may be moved as required into any one of
thrco positions, viz., "danger," "caution," and "all-right," by means
of one wire, and the Invention essentially consists in the construction

page_text: and employment of a peculiar form of cam which is carried by a slide
and receives a pin or roller on the ordinary weighted lever. The cam is
placed vertically, and in the normal position of the signal indicating,
say, "danger," the roller or pin is at the bottom of the cam. When the
signalman pulls upon the wire in the usual manner the weighted lever
is raised, and the roller or pin by pressing against the wall of an inner
groove of the cam causes the cam to slide forward, and when the
weighted lever is allowed to fall the roller or pin drops into a different
portion of the cam to that it before occupied and at a higher position so
that "caution" is indicated. When the attendant next pulls upon the
wire the roller or pin rises with the weighted lever up the side of the
cam to the top thereof, and if the parts be then held in this position the
signal will indicate all right;" when the lever is again released it falls
to its normal position of danger, and the roller returns down the
other side of the cam to the lowest point ready to recommence the
operation.
It will thus be understood that the first time the wire is pulled the
signal is moved from danger to caution and the second time from
caution to all right, returning from this position to danger as soon as the
wire is released; and these movements are effected with certainty.
In some cases I reverse the position of the cam and pin or roller, that
is to say, the cam is attached to the weighted lever and the pin or roller
to the slide, or the cam may be made to slide on the lever. In some
cases also the normal position may be "all right" or "caution" instead
of " danger."
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James John Frederick Stevens in the Great Seal
Patent Office on the 11th April 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, James
JOHN FREDERICK STEVENS, of Darlington Works, Southwark, in the 30
County of Surrey, Railway Signal Manufacturer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Thirteenth day of October, in the year
of our Lord One thousand eight hundred and seventy-one, in the thirty-

page_text: fifth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said James John Frederick Stevens, Her
special licence that I, the said James John Frederick Stevens, my
executors, administrators, and assigns, or such others as I, the said
James John Frederick Stevens, my exécutors, administrators, and
assigns, should at any time agree with, and no others, from time to time
and at all times thereafter during the term therein expressed, should
and lawfully might make, use, excrcise, and vend, within the United
Kingdom of Great Britain and Ireland, the Channel Islands, and Isle of
Man, an Invention for "IMPROVEMENTS IN APPARATUS FOR WORKING RAILWAY
SIGNALS," upon the condition (amongst others) that I, the said James
John Frederick Stevens, my executors or administrators, by an instru-
ment in writing under my, or their, or one of their hands and seals,
should particularly describe and ascertain the nature of the said Inven-
tion, and in what manner the same was to be performed, and cause
the same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said James John Frederick Stevens, dọ
hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, reference being had to the
accompanying Drawings, that is to say :-
The object of my Invention is so to construct apparatus for working
railway signals that a signal may be moved as required into any one of
three positions, viz., “danger,” “caution,” and “all right,” by means
of one wire, and the Invention essentially consists in the construction
and employment of a peculiar form of cam which is carried by a sliding
or shifting piece and receives a pin or roller on the ordinary weighted
lever. The cam is placed vertically, and in the normal position of the
signal, indicating, say, "danger," the roller or pin is at the bottom of
the cam. When the signalman pulls upon the wire in the usual manner
the weighted lever is raised, and the said roller or pin, or an additional
roller or pin carried by the weighted lever, by pressing against the wall
of an inner groove of the cam causes the cam to move or slide forward,
and when the weighted lever is allowed to fall the first named roller or
pin drops into a different portion of the cam to that it before occupied
and at a higher position, so that "caution" is indicated. When the
attendant next pulls upon the wire the said roller or pin rises with-the

page_text: weighted lever up the side of the cam to the top thereof, and if the parts
be then held in this position the signal will indicate "all right;" when
the lever is again released it falls to its normal position of danger, and
the roller returns down the other side of the cam to the lowest point
ready to recommence the operation.
It will thus be understood that the first time the wire is pulled the
signal is moved from " danger" to " caution" and the second time from
" caution "
to "all right," returning from this position to "danger" as.
soon as the wire is released; and these movements are effected with
certainty.
The manner in which my Invention may be carried into effect will be
understood by Figures 1 and 2 of the annexed Drawings, which are
respectively a front elevation and a side elevation.
A is the ordinary weighted lever, having its fulcrum at B on the back
plate C; D, is the chain to which the wire for lifting the weighted.
lever is attached, and E is the rod which connects the said lever with.
the signal; F is a shifting piece attached to the plate O by a pin G, on
which it is free to oscillate. This piece F is formed with a cam H of
such configuration as to act in the manner herein-after explained. I is a
pin on the lever A at the point where the rod E is attached, and K is an
additional pin or stud also on the lever A. The Figures show the parts.
in their normal or .66
danger" position, the pin I being at the bottom of
the cam H. When the signalman pulls upon the wire in the usual
manner the weighted lever A is raised, and the pin I rises up the side 1
of the cam while the pin K rises up the inner groove 2. When the pin I
passes the point 3 the pin K begins to press upon the part 4 of the wall of
the groove 2 so that the piece F which carries the cam moves on its
centre G towards the right of Figure 1, and when the lever A is allowed
to fall the pin I descends down the part 5 to the point 6, causing the
picce to shift further to the right. In this position of the parts
caution is indicated by the signal. When the wire is next pulled the
pin I rises up the side 7 of its cam to the top 8, causing the piece F to
shift to the left, while the pin K passes through the groove 9 to the
outside of the piece F. If the parts be held in this position the signal
will indicate "all right,' but as soon as the lever A is released it falls to its
normal position, the pin I returning down the side 10 of the cam to its
lowest point, as shewn in the Drawing. The signal cannot be moved at
once from "danger" to "all right" because the pin K by coming

page_text: against the stop 11 prevents the pin I being moved to the top 8 of the
cam until the signalman has first allowed it to drop to the "caution"
point 6.
Although I prefer to employ an additional pin or stud K it is not
essential, because the pin I may in its movement from "danger to
"caution" be made to press upon an inner wall of the cam corres-
ponding with the portion 4, and to come against a stop corresponding
with the stop 11. In this instance the piece F should be fitted so as to
slide longitudinally on the plate O instead of to oscillate on a pin or
centre G, as in the arrangement shewn in the Figures.
In some cases I reverse the position of the cam and pin, that is to
say, the cam is attached to the weighted lever and the pin to the sliding
or shifting piece, or the cam may be made to slide on the lever. Or the
shifting piece which carries the cam may be in the form of a cylinder
made to turn on pivots, as represented in Figure 3, in which F is the
cylinder, H the cam, and I a roller or pin carried by the rod E, which
connects the weighted lever with the signal. The point 6 of the cam
is the "caution" position of the roller I, as before, and 11 is a stop to
prevent the signal being moved at once from "danger" to "all right."
Instead of the normal position of the parts being "danger," as herein-
before described, it may be "all right" or "caution," according to
requirement.
And having now described the nature of my said Invention, and in
what manner the same is to be performed, I declare that I claim con-
structing apparatus for working railway signals substantially as herein-
before described and represented in the accompanying Drawings.
In witness whercof, I, the said James John Frederick Stevens,
have hereunto set my hand and seal, this Ninth day of April
One thousand eight hundred and seventy-two.
JAMES JOHN FREDERICK STEVENS. (L.S.)