Improvements in Fire Extinguishing and Alarm Apparatus
Year: 1899

page_text: Date of Application, 3rd Aug., 1899-Accepted, 18th Nov., 1899
COMPLETE SPECIFICATION.
Improvements in Fire Extinguishing and Alarm Apparatus,
A communication from abroad by FRANK GRAY, of 634, Rookery Building,
Chicago, in the County of Cook and State of Illinois, United States of
America, Gentleman.
.
I, JAMES GRIEVE LORRAIN, M.I.E.E., M.I.Mech. E., of Norfolk House, Norfolk
Street, London, W.C., in the County of Middlesex, Chartered Patent Agent, do
hereby declare the nature of this invention (as communicated to me from abroad)
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
This invention relates to means for sounding emergency alarms in automatic
fire extinguishing systems, and also to improvements in the valve apparatus and
alarm mechanism employed for such purposes.
In sprinkler systems, whether wet or dry, it is desirable to sound an alarm
whenever fuses are blown out, and to keep this alarm going continuously until the
emergency is passed. It is also important that any attempt to tamper with the
main valve, controlling the fluid supply, for the purpose of rendering the system
inoperative, should be immediately signalled by the sounding of a persistent alarm
and that the means controlling this alarm should be of such a nature that they
cannot be operatively disconnected except at the point where the alarm is to be
sounded, any attempt to this end, precautionary to tampering with the valve, only
resulting in the sounding of the alarm. The vehicle that I employ for trans-
mitting to the signalling apparatus the actuating effect of the original causation
is the fluid pressure in the pipes of the system beyond the main valve.
In dry pressure systems a body of air is confined in the sprinkling pipes above
the main valve and held against the pressure of the water by a supplementary
or differential check valve. This body of air is under less pressure than the water
pressure until a plug is blown, when there is first a fall in pressure, and then the
water rushing in at once nearly doubles the pressure in the pipes. Therefore, to
sound an alarm, indicating that the sprinkler system is in active operation, the
alarm apparatus must be held out of action by the normal or static pressure but
caused to sound by a rising pressure. But if the main valve is closed, cutting off
the water supply, and a fire started, the first fuse that melts will release the com-
pression on the air and there will be a fall in pressure to which the alarm
mechanism must also be susceptible. If then the valve is closed and a fuse opened
with the idea that the alarm will be cut out, the effect will only be to accelerate
the time of sounding. If a fuse is opened before the valve is closed, the water
will rush in and the alarm sound, and although the valve should be immediately
closed the ensuing reduction of pressure will only result in further operating it;
or if a by-pass is placed around the differential valve and a drainage passage
opened by the act of shutting the main valve, any closure of said valve will be
followed by a reduction in pressure in the air-loaded sprinkler pipes, and con-
sequent ringing or sounding of the alarm.
In wet-pipe systems the water is held in the pipes beyond the main valve

page_text: and cause the alarm to sound. But as the static pressure adopted is détermined
by exigencies and may be greater or less than the figures suggested, and as the
alarm is intended to be used with wet and dry systems indiscriminately, these
contacts would have to be capable of adjustment so as to be shifted according to
the pressure determined. It is simpler, however, and more advantageous, instead
of making the pointer itself the circuit closer, to place a fixed contact upon the
dial D and arrange a double contact circuit closer, movable with and adjustable
relatively to the pointer, to co-operate with said fixed contact.
Advisably such circuit closer is a disc E mounted upon and adjustable around
the insulated contact post which forms a continuation of the gauge spindle E³
and also carries the pointer. The disc has a gap e in one side with opposing
bevelled or knife edges e¹ and e, and being fitted over the reduced upper end of
the contact post by its central bore e³, is clamped by means of the binding nut E³,
with its gap in any requisite radial position. The fixed contact F is herein shown
as composed of two opposing springs fl and f electrically connected with the
dial D by means of their supporting brackets 13, and extending inward towards
the circuit closer so that their counter-setting contact pins F1 and F. may meet
in the gap on a plane connecting the knife edges of said closer. Thus any
movement of the closer to right or left with the pointer will force one or the other
knife edge between said contact pins establishing electrical connection, and if the
movement is continued the connection will also continue as the pins will ride upon
the plane surface of the closer disc extending around from one side of the gap to
the other. The operation will be the same, though not entirely so permanently
reliable if one of the springs of the fixed contact is dispensed with.
G and G represent the cells of a dry battery mounted upon the supporting
board. The positive pole or cell G is connected by lead with the insulated
binding post H set through the wall of the gauge box, and thence by spring
contact with the insulated contact post of the gauge spindle, and through this
to. the circuit closer. The dial 1 is supported upon insulating posts J, and the
negative pole of cell G¹ is connected with said dial by lead and insulated binding
post K, also set through the wall of the gauge box. L is an alarm bell connected
in series with the battery cells on the other side of the circuit.
.
In order to set the alarm ready for action the pressure is first established and
then the circuit closer is adjusted to centre its gap upon the fixed contact while the
pointer is indicating such pressure. Thereafter any change in pressure, whether
up or down, and however caused, will bring one or the other knife-edge against
the fixed contact, close the circuit and sound the alarm.
By forming the circuit closer as a gapped disk and mounting it upon and
adjusting it around the spindle which carries the pointer, so as to revolve with
said pointer, or in other words bringing it close to the axis of movement of the
pointer, a long contact surface is secured in small space, and adverse leverage
is reduced to a minimum, a matter of importance in pressure gauges, which are as
a rule weak in return to zero.
Coming now more particularly to the apparatus for inducing a change in
pressure and consequent sounding of the alarm by wilful disturbance of the main
valve: M is a relief pipe leading from the valve casing A2 and connecting with the
chamber therein, above the valve. Communication may be established between
this relief pipe and the main drain-pipe M' by means of a branch pipe m and stop-
cock m at a point beneath and removed from the main valve and its point of
manual operation, so that it may be drained when necessary.
It may also have a valved stub m², for packing in an independent pressure.
The relief pipe may terminate in an alarm mechanism B₁ of the nature of that
hereinbefore described and located at a distant station. N is the main valve
formed as a slide-valve and controlled by the screw-rod or spindle N¹ and the
hard-wheel N2 which may work in connection with an indicator n to show the
position of the valve. This main valve is hollow, having openings, N n', at the
front and back, and that which closes over the supply port is imperforate while

page_text: tributing pipes and main valve, of a relief pipe closed off so long as the main valve
is fully open, pressure controlled alarm mechanism to which said relief pipe
leads, and means actuated by the closing movement of the main valve whereby
said relief pipe is opened to the pressure of the system.
7. In a pressure fire extinguishing system, the combination with the dis-
tributing pipes and main valve, of a relief pipe closed off so long as the main
valve is fully open, alarm mechanism operated both by a rise and a fall in
pressure, to which said relief pipe leads, means whereby said pipe is packed with
a pressure above zero but less than the pressure of the system, and means actuated
in the closing movement of the main valve whereby said relief pipe is opened
to the pressure of the system.
8. In a pressure fire extinguishing system, the combination with the dis-
tributing pipes and main valve, of a relief pipe closed off so long as the main valve
is fully open, pressure controlled alarm mechanism at all times in connection
with said pipes to be operated by variation of pressure therein, pressure controlled
alarm mechanism to which said relief pipe leads, and means operated in the
closing movement of the main valve whereby said relief pipe is opened to the
pressure of the system.
9. In a pressure fire extinguishing system, the combination with the dis-
tributing pipes and main valve, of alarm mechanism pipe connected with said
distributing pipes and operated by either rise or fall of pressure and a relief valve
opened in the incipient closing movement of the main valve.
10. In an electric alarm, the combination of a pressure gauge, an alarm circuit,
a double contact connected with one side of the circuit, and adjustable bodily
around the axis of the pointer of said gauge, an opposing contact connected with
the other side of said circuit, and means whereby the circuit is closed by move-
ment of the guage spindle in either direction.
11. In an electric alarm, the combination of a pressure gauge, an alarm circuit,
a gapped contact disc mounted upon and adjustable around the spindle which
carries the pointer, and connected to one side of the circuit, and a stationary
contact connected to the other side of the circuit.
12. In an electric alarm, the combination of a pressure gauge, an alarm circuit,
a gapped contact disc mounted upon and adjustable around the spindle which
carries the pointer, and having knife edges each side of the gap, a stationary
contact consisting of two opposing springs with countersetting contact points
mounted on a fixed part of the gauge, and leads connecting the disc with one
side of the circuit and the stationary contact with the other side.
13. In an electric alarm, the combination of a pressure gauge, the insulated
contact post forming an extension of its spindle, the gapped contact disc adjust-
able there around and moving therewith, the conducting spring resting on said
post, and the stationary contact secured to a fixed part of the gauge.
Dated this 3rd day of August 1899
J. G. LORRAIN, C.P.A.,
Communicatee.
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