IM- PROVEMENTS IN AND CONNECTED WITH STREET AND OTHER FIRE ALARM TELEGRAPHS
Year: 1879

page_text: LETTERS PATENT to Robert Stevenson Symington, of Glasgow, in the County
of Lanark, North Britain, Telegraph Engineer, for the Invention of "IM-
PROVEMENTS IN AND CONNECTED WITH STREET AND OTHER FIRE ALARM
TELEGRAPHS."
Sealed the 2nd September 1879, and dated the 5th March 1879.
PROVISIONAL SPECIFICATION left by the said Robert Stevenson Symington
at the Office of the Commissioners of Patents on the 5th March 1879.
ROBERT STEVENSON SYMINGTON, of Glasgow, in the County of Lanark, North
Britain, Telegraph Engineer. "IMPROVEMENTS IN AND CONNECTED WITH STREET
AND OTHER FIRE ALARM TELEGRAPHS."
This Invention comprises improvements in or connected with street and other
fire alarm telegraphs of or similar to the kind at present in use in Glasgow, and
also more or less applicable to other systems. In the Glasgow system numerous
fire alarm boxes are fixed in prominent positions in the streets and are connected
with district fire stations, and the district fire stations are connected with the
central fire station. Each street alarm box is, according to the present Invention,
fitted with an improved push key to be pushed inwards by the person using the
alarm. This push key is carried in a small barrel or tube and is pressed outwards
by a spring, and when it is pushed inwards it causes a spring arm to make a
contact which closes the circuit of the wire to the district station and sounds the
electric bell at that station. The push key is made tubular to receive an improved
connector or switch plug which is connected to a portable Wheatstone or other
suitable telegraphing instrument or telephone, by a pair of insulated wires corre-
sponding respectively to the line wire and the earth wire. The switch plug is
formed with a handle of wood or other suitable material, and with a metal tube to
be entered into the push key, and an insulated wire corresponding to the line wire
passes through the tube and projects from its end, whilst the other insulated or
earth wire is connected to the tube. When the switch plug is inserted in the
push key its tube makes contact with the key and through it connects to earth,
whilst the central wire makes contact with the spring arm and through it connects
TD 037

page_text: with the line wire proceeding to the district station, and at the same time depresses
the spring arm midway between and out of contact from the earth and battery
connection. In this way a portable telegraphing instrument can be instantly
connected to any of the street alarm boxes without any screwing or unscrewing
of wires or other parts, and give the fireman or others the power of communicating
with the district station, and through that station with the central station. At
the district station a similar improved push key is fitted in connection with the
wire from each street box, and a switch plug is connected to the instrument com-
municating with the central station. Ordinarily this switch plug is entered into
a fixing giving connection with earth, but when required it is inserted into the
push key connected to one of the street aların boxes, and then communications can
be transmitted directly between the central station and the particular street aların
box.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Robert Stevenson Symington in the Great Seal Patent Office on
the 3rd September 1879.
ROBERT STEVENSON SYMINGTON, of Glasgow, in the County of Lanark, North
Britain, Telegraphs Engineer. "IMPROVEMENTS IN AND CONNECTED WITH STREET
AND OTHER FIRE ALARM TELEGRAPHS."
My said Invention comprises improvements in and connected with street and
other fire alarm telegraphs of or similar to the kind at present in use in Glasgow,
and also more or less applicable to other systems. In the Glasgow system numerous
fire-alarm boxes are fixed in prominent positions in the streets and are connected
with district fire stations, and the district fire stations are connected with the
-central fire station. Each street alarm box is by my present Invention fitted with
an improved push key to be pushed inwards by the person using the alarm, and
hereinafter particularly described. The push key is made tubular to receive an
improved connector or switch plug which is connected to a portable Wheatstone
or other suitable telegraphing instrument or telephone by a pair of insulated wires
corresponding respectively to the line wire and the earth wire. When the switch
plug, which is hereinafter particularly described, is inserted in the push key, a
connection is instantly formed without any screwing or unscrewing of wires or
other parts, and gives the fireman or others the power of communicating with
the district station, and through that station with the central station. At the
district station a similar improved push key is fitted in connection with the wire
from each street box, and a switch plug is connected to the instrument communi-
cating with the central station. Ordinarily this switch plug is entered into a
fixing giving connection to earth, but when required it is inserted into the push
key connected to one of the street alarm boxes, and then communications can be
transmitted directly between the central station and the particular street alarm box.
And in order that my said Invention and the manner of performing the same
may be properly understood, I hereunto append a Sheet of explanatory Drawings
to be hereinafter referred to and representing examples of my improved apparatus
and arrangements. In these Drawings the same reference numerals are used to
mark the same or like parts wherever they are repeated.
Figure 1 on the accompanying Sheet of Drawings is a front elevation of one
of the street fire-alarm boxes, and Figure 2 is a vertical section of the same;
Figure 3 represents a small portable instrument furnished with a switch plug for
connection with the fire-alarm box; Figure 4 represents the instruments at a
district station; and Figure 5, those at the central station; Figures 6 and 7 are
an enlarged plan and a front elevation of the push key details; and Figures 8 and
9 are vertical sections thereof, the latter showing the switch plug inserted in the
push key; Figure 10 is an enlarged section of the switch plug.
The push key 11 is a tube having an annular head on its outer end on which
the word "push" is marked, and it is carried in a tubular bearing 12, fixed on
a three-armed bracket 13. A helical spring is arranged inside the tubular
bearing 12 to press the push key 11 outwards, and when the key is pushed
inwards its inner end acts on a metal spring 14, and causes it to make a contact
with a piece of metal 15, thereby closing the circuit of the wire to the district
station and sounding the bell at that station. The spring arm or switch 14 is
connected to the line wire 16 and the metallic piece 15, into contact with which
it is pushed by the key 11, is connected by a wire 17 to the battery 18 shewn
in Figure 2, as occupying the upper part of the fire-alarm box. When the spring
arm or switch 14 is not pressed in, it forms a contact with a metallic piece 19,
which is connected by a wire 20 with the electro-magnetic bell 21 in the fire
alarm box, and this bell can consequently be sounded from the district station to
show that the alarm signal.has been noticed.

page_text: The switch plug is formed with a handle 22 of wood or other suitable material,
and with a metal tube 23 to be entered into the push key 11, and an insulated
wire 24 corresponding to the line wire 16 passes through the tube 23, and projects
slightly from its inner end, whilst another insulated wire 25, corresponding
to the earth wire is connected to the tube 23. The two wires thus con-
nected to the switch plug are formed into a flexible cord 26, and connected
to the portable instrument 27 (Figure 3). When the switch plug 22, 23, is'
inserted in the push key 11 (as shown in Figure 9), its tube 23 makes contact
with the key 11, and through it and the bracket 13 connects to earth, the bracket
having connected to it a wire 28 which is connected to earth in the ordinary way, 1
whilst the central wire 24 makes contact with the spring arm or switch 14, and
through it connects with the line wire 16 proceeding to the district station, and at
'the same time depresses the said spring arm 14 to a position midway between and
out of contact from the battery and bell connections 15, 19. When these connec-
tions are made as described, telegraphic messages can by means of the portable 1
instrument 27 be transmitted between the street fire-alarm box and the district
station, or the central station when the necessary connection is made at the district
station.
At the district station (Figure 4) there is provided for each street fire-alarm
box that is in connection with the station an electro-magnetic_bell 29, and a push
key mounting 30 like those in the street fire-alarm box. The parts are arranged
so that by simply pushing in the key (11) the receipt of an alarm signal is acknow-
ledged, the bell 21 at the street box being thereby sounded, whilst by inserting in
the push key a switch plug (22, 23,) an instrument may be put into connection for
transmitting messages. Or there may be inserted in the push key (11) of the a
district apparatus a switch plug 31 connected to an instrument 32, which is con-
nected by a wire 33 with the central station, Figure 5, so that messages may be
transmitted directly between any particular street fire-alarm box and the central
station.
Having thus particularly described my said Invention, and the manner of per-
forming the same, I have to state that I do not restrict myself to the precise
details herein described or delineated, but that what I believe to be novel and
original, and claim as the Invention secured to me by and in terms of the herein-
before in part recited Letters Patent is,-
1. The arranging or combining together of the push key and push-key accessories
of street and other fire alarm telegraphs, substantially in the improved manner
heroinbefore described.
2. The construction and mode of application of the push key, as hereinbefore
described.
3. The construction and mode of application of the switch plug, as hereinbefore
described.
4. The adaptation of the push key and switch plug to each other, substantially
as berein before described.
In witness whereof, I, the said Robert Stevenson Symington, have hereunto
set my hand and seal, this Second day of September, in the year of our 4
Lord One thousand eight hundred and seventy nine.
Witness,
EDMUND HUNT,
Patent Agent,
Glasgow.
R. S. SYMINGTON. (L.S.)