IMPROVEMENTS IN AND CONNECTED WITH ELECTRICAL INSTRUMENTS FOR SIGNALLING ON RAILWAYS
Year: 1872

page_text: LETTERS PATENT to John Brewer Saunders, of Taunton, in the
County of Somerset, Telegraph Engineer, for the Invention of
"IMPROVEMENTS IN AND CONNECTED WITH ELECTRICAL INSTRUMENTS FOR
SIGNALLING ON RAILWAYS."
Scaled the 27th August 1872, and dated the 1st March 1872.
PROVISIONAL SPECIFICATION left by the said John Brewer Saunders
at the Office of the Commissioners of Patents, with his Petition,
on the 1st March 1872.
I, JOHN BREWER SAUNDERS, of Taunton, in the County of Somerset,
Telegraph Engineer, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN AND CONNECTED WITH ELECTRICAL INSTRUMENTS FOR
SIGNALLING ON RAILWAYS," to be as follows:-
My Invention consists of an arrangement as hereafter described
whereby the block signal instrument shews on the dial or screen whether
an "up" or a "down" train is approaching a station or not; this is
done mechanically as follows:-The blocking of the handle or tapper,

page_text: or the pressing in of the plunger whereby the current is passed throws
up a disc or plate bearing the words "up train approaching," or "down
train approaching," or equivalent words or signs as the case may be.
In the case of instruments worked by a permanent current, the disc or
plate remains in position until the block pin is removed, when it (the
disc or plate) disappears behind the screen or dial plate, but in the case
where two plungers are used each to send an intermittent current, the
pressing in of one throws up the disc or plate into position, and the
same action with the other plunger displaces it.
My Invention further consists of an arrangement whereby the block-
ing pin used for fixing the handle or tapper to send the permanent
current for blocking the line bears upon it a plate having the inscrip-
tion "up train approaching," or "down train approaching," as the case.
may be, or signs or words to that effect, the pins being so formed that
when placed in the aperture the plate can only shew in one direction,
thereby preventing its being placed in a wrong position.
The Invention is specially applicable to electrical instruments used
for signalling trains by means of what are known as block signal
instruments.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John Brewer Saunders in the Great Seal Patent
Office on the 30th August 1872.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
BREWER SAUNDERS, of Taunton, in the County of Somerset, Telegraph
Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the First day of March, in the year of our Lord
One thousand eight hundred and seventy-two, in the thirty-five year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said John Brewer Saunders, Her special licence that I,
the said John Brewer Saunders, my executors, administrators, and
assigns, or such others as I, the said John Brewer Saunders, my
executors, 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,

page_text: exercise, and vend, within the United Kingdom of Great Britain
and Ireland, the Channel Islands, and Isle of Man, an Invention for
"IMPROVEMENTS IN AND CONNECTED WITH ELECTRICAL INSTRUMENTS FOR SIGNALLING
ON RAILWAYS," upon the condition (amongst others) that I, the said John
Brewer Saunders, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention,
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 monthis next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said John Brewer Saunders, do 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, reference being had to the accom-
panying Drawings and to the letters of reference marked thereon, that
is to say:
6
My Invention is specially applicable to electrical instruments used
for signalling trains by means of what are known as block signal instru-
ments, and my Invention consists, first, of an arrangement as hereafter
described whereby the block signal instrument is caused to show on the
dial or screen whether an "up" or a down "train is approaching a
station or not; this is done mechanically as follows:-The blocking
of the handle or tapper, or the pressing in of the plunger whereby the
current is passed, throws up a disc or plate bearing the words "up train
approaching" or "down train approaching," or equivalent words or signs,
as the case may be. In the case of instruments worked by a permanent
current the disc or plate remains in position until the block pin is
removed, when it (the disc or plate) disappears behind the screen or dial
plate, but in the case where two plungers are used each to send an
intermittent current, the pressing in of one throws up the disc or plate
into position, and the same action with the other plunger displaces it.
t
Figure 1 of the accompanying Drawings is a front elevation of a
block signal instrument fitted according to my Invention, shewing the
blocking pin inserted in its aperture and the disc raised; Figure 2 is a
front elevation of the same with the pin withdrawn and the disc down
or behind the screen; Figure 3 is a side elevation of the disc, blocking
handle, pin, and apparatus connected therewith, and Figure 4 is a front

page_text: elevation of the same partly in section, shewing clearly the disc, disc
rod, lever, and pin whereby motion is communicated to the disc.
a is the disc bearing such inscription as may be desired, and according
to whether it is the instrument for the up or down line; b is a lever
connected to it; c is the centre or pin on or about which the lever b
works; d is a rod passing through the case of the instrument to the
outer side thereof; e is a short lever or cam on the end of the rod d; f
is the blocking pin passing through an aperture formed in the axle of
the instrument, and g is a spring connected to the end of the lever b
for drawing same back when released.
The action is as follows:-To block the line insert the pin f in the
axle till the end of the pin is caused to press against the end of the
short lever e, which is thereby depressed at the same time throwing up
the lever and disc a to view, from which position it cannot move until
the pin f is removed, when the spring 9 draws the lever b and with it
the disc a behind the screen, viz., from the position in which it is shewn
at Figure 1 to the position in which it is shewn at Figure 2. Thus it
will be understood that with instruments fitted with apparatus in the
manner before described it is practically impossible for the signalman
to make mistakes, because in the event of his going to the wrong instru-
ment and having blocked the wrong line the disc which is thereby
brought up immediately shews him his error which he can instantly
rectify.
My Invention further consists of an arrangement whereby the blocking
pin used for fixing the handle or tapper to send the permanent current
for blocking the line bears upon it a plate having the inscription "up
train approaching" or down train approaching," as the case may be,
or signs or words to that effect, the pins being so formed that when
placed in the aperture the plate can only shew in one direction, thereby
preventing its being placed in a wrong position.
Having now described the nature of the said Invention, and in what
manner the same is to be performed, I declare that I do not limit myself
to the particular or precise arrangement before described for causing the
disc to rise or fall and keeping it in the required position, although I
have found the arrangement described a convenient way of carrying my
Invention into effect; but I claim,―
First. The causing of a disc or plate with or without an inscription to
rise and to be exposed to view on the dial of the instrument simulta-

page_text: neously with the blocking of the line and so long as it is blocked, and
to disappear simultaneously with the line being cleared, and to be
behind the screen of the instrument so long as the line is clear and not
blocked.
Second. The arrangement or arrangements for causing the disc or
plate to rise or fall, substantially as herein-before described and illustrated
in the accompanying Drawings.
Third. Fitting a plate to the blocking pin for shewing when it is used
to block the line whether it is the up or down line that is blocked,
substantially in manner herein-before described.
In witness whereof, I, the said John Brewer Saunders, have here-
unto set my hand and seal, this Twenty-eighth day of August,
in the year of our Lord One thousand eight hundred and seventy-
two.