Improved Electric Automatic Fire Alarm.
Year: 1888

page_text: Date of Application, 10th Dec., 1889
Complete Specification Left, 10th Sept., 1889-Accepted, 19th Oct., 1889
PROVISIONAL SPECIFICATION.
Improved Electric Automatic Fire Alarm.
We, HOWELL BENSON PHILLIPS, Agent, and WILKINSON MITCHELL, Stockbroker,
both of Nos. 28 and 29, St. Swithin's Lane, in the City of London, E.C., do hereby
declare the nature of this invention to be as follows:-
Our invention relates to improvements in fire alarins, and consists in the com-
bination with an electric circuit, of a spring contact held back from its fellow against
the resilience of the spring, by a cement that melts at a temperature safely below
that of a conflagration. We do not confine ourselves to any particular cement, but
may make use of any that are possessed of the required property in respect of their
melting points, but we instance a compound of paraffin wax and tallow as a proper:
cement for ordinary risks.
In carrying our invention into effect, we provide a suitable base, e.g., a wood tablet,
through which a circuit of an electrical bell is led. The circuit is interrupted by a
pair of contacts. One of these is fixed, while the other is movable, and is adapted to
slide in guides. The opposite end of the movable contact enters a suitable cup, in
which it is held by the cement above mentioned, against the force of a circuit-closing
spring. As soon as the outbreak or approach of a fire raises the temperature of the
cement above its melting point, the spring closes the circuit and the alarm
is given.
Dated this 10th day of December 1888.
PHILLIPS & LEIGH,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improved Electric Automatic Fire Alarm.
We, HOWELL BENSON PHILLIPS, Agent, and WILKINSON MITCHELL Stockbroker,
both of Nos. 28 & 29, St. Swithin's Lane, in the City of London, E.C., do hereby
declare the nature of this invention and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:-
Our invention relates to improvements in fire alarms, and consists in the com-
bination with an electric circuit, of a spring contact, held back from its fellow against
the resilience of the spring, by a cement that melts at a temperature safely below
that of a conflagration. We do not confine ourselves to any particular cement, but
may make use of any that are possessed of the required property in respect of their
inelting points, but we instance a compound of paraffin wax and tallow as a proper
cement for ordinary risks.
In carrying our invention into effect, we provide a suitable base, e.g., a wood tablet
through which a circuit of an electrical bell is led. The circuit is interrupted by a
pair of contacts. One of these is fixed, while the other is movable, and is adapted to
slide in guides. The opposite end of the movable contact enters a suitable cup in
which it is held by the cement above mentioned against the force of a circuit-closing
spring. As soon as the outbreak, or approach of a fire, raises the temperature of the
cement above its melting point, the spring closes the circuit, and the alarm
is given.
In order that our invention, and the means of carrying the same into practical effect,
may be thoroughly understood, we will now describe it in detail, referring in so

page_text: "
doing to the accompanying drawing which is to be taken as part of this specification
and read therewith."
Fig. 1 is a front elevation..
Fig. 2 is a side elevation.
A Bare parts shewn as severed for convenience of illustration-of the electric
bell (or equivalent alarm) circuit; C is the spring contact; D, the spring; and E
the cement in a cup e. The lower end of the spring contact C is expanded into a
disc c, or its equivalent, for the purpose of increasing the surface upon which the
cement can exert its restraining influence. F is the fixed contact. G is a pin provided
for the purpose of holding the inovable contact away from its fellow by being inserted
in the hole g, and so preventing undue strain upon the cement.
The operation of our invention is as follows:-
A sufficient number of our electric automatic fire alarms being fixed throughout,
say, a mansion or a warehouse; when conflagration breakes out therein, then will
the increase of temperature, conveyed to the cement either through the atmosphere
or through the fabric of the building, melt the said cement, and therefore lead to the
instantaneous reporting of the conflagration, said reporting being consequent upon
the automatic closure of the electric alarm circuit or circuits.
It is obvious that the mechanical, as distinguised from the electrical features of
our invention, may be varied more or less as circumstances may render desirable or
novel demands may necessitate; and we therefore wish it to be distinctly understood
that the accompanying drawing is only an illustrative one, at the same time it is at
the same time illustrative of what we regard as substantially the most convenient
embodiment of our invention. It is not the mere illustrated mechanism which is
the subject of our invention, but the combination of electrical functions discharged
by material devices adapted thereto.
Having now particularly described and ascertained the nature of our said inven-
tion, and in what manner the same is to be performed, we declare that what
we claim is :-
The combination of electric alarm circuit; contacts, one of which is adapted to be
held back from its fellow against the resilience of a circuit-closing spring by a
cement fusible at a safely low temperature; and the said circuit-closing spring, as
and for the purpose set forth.
Dated this 10th day of September 1889
PHILLIPS & LEIGH,
No. 22, Southampton Buildings, Chancery Lane, W.C., Agents for the Applicants.