IMPROVE MENTS IN SELF-ACTING FIRE-ALARMS
Year: 1866

page_text: LETTERS PATENT to John Henry Johnson, of 47, Lincoln's Inn Fields,
in the County of Middlesex, Gentleman, for the Invention of "IMPROVE
MENTS IN SELF-ACTING FIRE-ALARMS."-A communication from abroad by
Charles Dion, of the City of Montreal, in the Province of Canada,
Photographic Artist.
Sealed the 6th November 1866, and dated the 14th May 1866.
PROVISIONAL SPECIFICATION left by the said John Henry Johnson
at the Office of the Commissioners of Patents, with his Petition, on
the 14th May. 1866.
I, JOHN HENRY JOHNSON, of 47, Lincoln's Inn Fields, in the County of
Middlesex, Gentleman, do hereby declare the nature of the said Invention
for "IMPROVEMENTS IN SELF-ACTING FIRE-ALARMS," a communication to me from
abroad by Charles Dion, of the City of Montreal, in the Province of Canada
Photographic Artist, to be as follows:-
This Invention relates to certain improvements upon and modifications of
the self-acting fire alarms for which Letters Patent were granted to me on
the 2nd of May 1865, No. 1223, and has for its object the simplification of
such apparatus the rendering its action more prompt, and less liable to get
out of order, whilst at the same time the cost of construction is reduced.
In carrying out this Invention it is proposed to substitute a straight

page_text: compound metal spring composed of steel and copper in about equal
proportions, or of steel and zinc, or copper and zinc, or an expanding and
contracting wire (composed by preference of German silver) for the spiral
compound spring described in the Specification of the Patent above referred
to, and to adapt the straight compound spring or metal wire to several
different arrangements or modifications of mechanism for giving an alarm in
case of the existence of fire or of an unduly elevated temperature in that part
of the building where the compound spring or wire is situate.
According to one modification a straight spring of compound metal is
secured at its lower end to a bed plate fixed to a wall or otherwise, and its
position at the free end adjusted by the aid of an adjusting screw and an
ordinary blade spring, according to the temperature at which the alarm is to
be given, a divided scale being employed for that purpose, either attached to
the wall or formed on a pin or stud carried by the compound spring itself, or
fitted into the upper end of a vertical tipping lever; this lever turns on a
pivot at its lower end, and is held in a nearly vertical position by the pin or
stud above referred to, which engages either in a hole in the free end of the
compound spring or in a hole in the tipping lever, according as the said stud
or pin is carried by the spring or by the lever. Towards the lower part of
the wall plate there is pivoted a bent lever, one arm of which has a hole made
in it through which passes the stem of a weight which rests upon a stationary
knife-edged bracket. So long as the stem of the weight is engaged with the
end of the bent lever the weight remains supported upon its bracket, but
when the stem is released the weight falls; this release of the stem is effected
by the elevation of the temperature to the given degree acting upon the
compound spring, and causing it to deflect until it releases the vertical tipping
lever by withdrawing the stud or pin; this lever on turning over strikes
against the free arm of the bent lever, and by raising the opposite end
engaged with the stem of the weight releases that weight, which being
attached by a string or wire to the crank movement of a bell wire, and thus
gives the alarm by ringing the bell. If the vertical tipping lever be made
sufficiently heavy it may be connected directly with the bell, so that in falling
it will ring the same, thus dispensing with the bent lever and weight.
According to another modification the straight compound spring is attached
to the lower external part of a tube secured vertically to a wall, and the
deflection of this spring by the elevated temperature releases a small trap-
door in the upper part of the tube, such door supporting a marble or weight,
which falls immediately the door is released, and by striking against a lever,
as described in my said former Specification, starts the alarm bell.

page_text: Another modification consists in fixing the compound straight spring at its
upper end, and engaging its lower free end into a bent catch on a weight
resting upon a knife-edged bracket. The position of the upper end of the
spring is adjustable laterally, according to the temperature, and that at any
given degree of heat the deflection shall be sufficient to release the weight,
which sounds the bell, as described above, by a cord, wire, or chain.
According to another arrangement the result is obtained by the expansion
under an elevated temperature of a long wire (by preference of German silver)
in lieu of by the deflection of a straight compound metal spring; this wire is
secured at one end to the wall of an apartment; and connected at its other
end to the shorter arm of a lever turning upon a fixed centre, and having
suspended to its longer arm a weight which tends always to keep the wire
taut. Immediately beneath this weight there projects the shorter arm of a
second lever, the end of the longer arm of which engages with a pin or stem
in a weight supported on a knife-edged bracket. A scale, as in the previous
arrangement, serves to facilitate the adjustment of the apparatus so as to
come into operation at any given temperature. The elevated temperature by
acting on the wire causes it to expand or elongate, hence the weight on the
first lever will descend, and in so doing will press upon the short end of the
second lever, and raise the opposite end; this elevation of the longer end of
the second lever has the effect of releasing the weight, which in falling rings
an alarm bell,
In another arrangement a straight compound metal spring is placed either
vertically or horizontally against a wall, and adjusted at one end to the given
temperature by means of a set screw spring and scale, whilst its opposite free
end is provided with a small hole for the reception of the booked or bent end
of a horizontal tipping lever, which is connected to the wall by a pivot or
fulcrum pin. A sliding weight is placed upon this lever between the bent
end and the fulcrum, and is connected by a string or otherwise with a bell;
at the other end of this lever there is fixed a small compensating weight: As
the temperature rises the compound spring increases in length, and frees itself
from the hooked end of the lever, allowing its long arm to fall, and in so doing
permitting the sliding weight also to fall, moving along the lever to its lower
end, and thereby ringing the alarm bell.
According to a sixth modification an expanding wire; by preference of
German silver, is again substituted for the compound metal spring; this wire
is stretched across the apartment, being connected at one end to the wall and
at the other to the short arm of a vertical lever, which is acted upon by a
spring so as to keep the wire in a state of tousion. The lower end of the long

page_text: arm of this lever carries an adjustable screw, which bears against the lower
end of the short arm of a second vertical lever, the upper end of the long arm
of which has a small hole made therein in order to engage with a stud or pin
in the side of a tipping weight or weighted lever working on a fulcrum. The
opposite side of the weight has a large falling weight suspended thereto, and
through an opening in the centre of this weight there passes a rod or wire
with a button or stop on the lower end, whilst its upper end is connected to a
crank lever for sounding a bell. The undue expansion of the wire causes the
vertical levers to turn slightly on their centres, whereupon the tipping weight
being released and allowed to turn over slightly the falling weight becomes
detached, and in its descent on to the button or stop on the wire rings the
alarm bell.
This apparatus is set to operate at any given increase of temperature. by
means of an index hand and dial, the hand being connected by a rod and
short lever arm with the lower end of the first mentioned of the two vertical
levers, so that by turning the index hand to any given position on the dial
the vertical lever will be more or less turned on its centre, and set to operate
at the given elevation of temperature. In lieu of the tipping and falling
weights above referred to a second index hand or lever may be fitted loosely
on the axis of the first index hand, so as to be acted upon by that hand as it
moves round by the expansion of the wire and consequent deflection of the
lever with which it is connected. This second hand or lever is engaged at its
extremity with one or other of a series of notches in a weighted tipping lever,
and when it is raised by the first hand coming against it, the weighted tipping
lever being released turns over on its centre, and either rings a bell by well-
known mechanical connections, or establishes an electrical circuit, which may
be made to give an alarm in various ways, as is well known.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Henry Johnson in the Great Seal Patent Office on
the 14th November 1866.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
HENRY JOHNSON, of 47, Lincolu's Inn Fields, in the County of Middlesex,
Gentleman, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Fourteenth day of May, in the year of our Lord
One thousand eight hundred and sixty-six, in the twenty-ninth year of Her

page_text: reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said John Henry Johnson, Her special license that I, the said John
Henry Johnson, my executors, administrators, and assigns, or such others
as I, the said John Henry Johnson, my executors, administrators," or
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, exercise, and vend, within the United Kingdom
of Great Britain and Ireland, the Channel Islands, and Isle of Man, an
Invention for "IMPROVEMENTS IN SELF-ACTING FIRE-ALARMS," a communica-
tion to me from abroad by Charles Dion, of the City of Montreal, in the
Province of Canada, Photographic Artist, upon the condition (amongst
others) that I, the said John Henry Johnson, my executors or administrators,
by an instrument in writing under my hand and seal, 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
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 John Henry Johnson, do hereby declare
the nature of the 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 accompanying Drawings, and to the
letters and figures marked thereon, that is to say :-
The said Invention relates to certain improvements upon and modifications
of the self-acting fire-alarms for which Letters Patent wero granted to me on
or about the Second of May One thousand eight hundred and sixty-five,
No. 1223, and has for its object the simplification of such apparatus, the
rendering its action more prompt and less liable to get out of order, whilst
at the same time the cost of construction is reduced.
In carrying out this Invention it is proposed to substitute a straight
compound metal spring composed of steel and copper in about equal pro-
portions, or of steel and zinc, or copper and zinc, or an expanding and
contracting wire (composed by preference of German silver) for the spiral
compound spring described in the Specification of the Patent above referred
to, and to adapt the straight compound spring or metal wire to several different
arrangements or modifications of mechanism for giving an alarm in case of
the existence of fire or of an unduly elevated temperature in that part of
the building where the compound spring or wire is situate.
And in order that the said Invention may be fully understood I shall now
proceed more particularly to describe the same, and for that purpose I shall

page_text: refer to the several Figures on the annexed Sheet of Drawings illustrating
six different modifications of the said apparatus, the same letters of reference
indicating corresponding parts in all the corresponding Figures.
Figures 1 and 2 represent respectively a front and side elevation of
modification No. 1. In this modification A is the compound spring, which
is attached at its lower end to a metal or other plate B secured to a wall, and
is regulated or adjusted by a screw a and secondary spring 6 also attached to.
the plate B at one end and acting with its other end against the first compound
spring A. Near the upper end of the spring A there is a small hole for the
reception of a short pin d attached to the upper end of a nearly vertical falling
lever D, or this pin may be attached to the compound spring A and work in
a small hole in the falling lever, as may be desired. On this pin a graduated.
scale may be placed to indicate the temperature at which the alarm should
act, if so required, or this scale may be attached to the board holding the.
alarm in immediate proximity with the spring, and perform a similar service.
The falling lever referred to may be supported at its lower end on a pivot c,
on which it will loosely revolve, or it may be placed on a knife edge. When.
the spring A expands by the action of heat the pin d release the lever D, and
in folding this lever strikes a bent lever E working on a pivot e. One end of
the lever E is perforated for the reception of the end of a rod f attached
to the falling weight F which is supported on a knife edge g, as shewn in the
Drawings. This falling weight may be attached by a wire chain or cord to.
the crank movement of a bell wire, and thus give the alarm, to be more
particularly described hereafter.
The modification No. 2 is represented in front elevation and vertical section
at Figures 3 and 4 respectively. It consists of a compound spring A similar
to that already described, and provided with the same mode of adjustment by
means of a regulating screw a and spring 6 at the lower end. The spring A.
is secured at the lower end of a tube B, which is placed on the side wall of
the room; at the upper end of this spring is a small hole for the reception of
the end of a small pin d which is connected to a tilting platform D on the
inner side of the tube; this tilting platform supports a marble or other weight,
and when the spring expands by the elevation of temperature it releases or
withdraws the pin d from the platform and allows the latter to tilt so that the
marble falls through the tube and gives the alarm by means of an arrangement
similar to that described in the Specification. of my Patent herein-before
referred to. A graduated temperature scale is also attached to the upper end
of the tube, and serves to regulate the action of the machine to any require
degree of temperature.

page_text: Modification No. 3 is represented in front and side elevation at Figures 5
and 6. It consists of a compound spring A of any suitable length and suspended
from the end of a metal tube or socket a attached by a suitable bracket 6 to
the bed plate or wall. This connection of the compound spring with the tube
is susceptible of a movement for adjustment of the spring by means of a
slide c working in the socket and held in place by a clamp screw d; or in place
of this arrangement the spring may have a small ferrule attached to its upper
end, and have a small pivot proceeding from the wall plate and passing into the
ferrule, with a suitable clamp screw for fixing its position. A temperature.
scale may be either marked on the tube or pivot or it may be attached to,
the bracket and suitably adjusted with the spring. At the lower end of the
spring there is a small hole for the reception of a pin fattached to a weight F
which rests on a knife edge g. This weight may be attached by a cord,
wire, or chain to the, crank of a bell wire, and if the spring expands by.
the heat sufficiently to release the weight such weight will fall and give the
alarm.
The modification No. 4 is represented by Figure 7, and may be arranged,
in the following manner:-A metal wire a, by preference a German silver
wire, of any suitable length is attached to the wall of a room, one end being:
made fast and the other end secured to the end of a lever b which turns or
partly rotates on a pivot c fixed to the wall. This pivot will not be in the
centre of the lever, but by preference is placed at a point near the end where.
the wire attachment is made, thus dividing the lever into a long and short
arm. At the extreme end of the long arm a weight d is suspended for the.
purpose of keeping the wire taut, and merely rests on the top of the short
arm to a second lever e, likewise partly rotating on a pivot f secured in a bed,
plate or to a wall. The handle of this weight is provided with a screen arrange-
ment by which the weight may be adjusted to any required degree of
temperature in connection with the elongation or contraction of the wire,.
which in this case takes the place of the spring, or a graduated scale may be
fixed opposite the long arm of the first or second lever so as to indicate the.
degrees of heat. At the outer end of the long arm of this second lever e there
is a hole perforated for the reception of the end of a pin g fixed in a second,
weight h resting on a knife edge i or other suitable support. This weight h;
may be connected by wire, chain, or cords to the crank arrangement of a
bell wire. When the lever 6 turns by the expansion of the wire the weight d
sinks down, and the second weight & being released falls, thereby sounding an;
alarm.

page_text: The modification No. 5 is shewn in Figures 8 and 9, and may be thus
described. A compound spring A is placed either vertically or horizontally
and regulated at one end, as described in reference to modifications No. 1
or No. 8, by means of screws and springs. At the other end there is a small
hole for the reception of the hooked end of a bent lever a of suitable length,
near the opposite end of this lever is a pivot arrangement 6 connecting it to
the wall on which the lever turns. A sliding weight o is placed on the long
arm of the lever a, and as the end of the lever is a compensating weight
stationary on the lever, the moveable larger weight is intended. to be
connected by a chain, string, or wire with the crank movement of a bell wire.
The modification No. 6 is shewn in Figures 10, 11, 12, and 13, and may
be thus described. G is a lever working on a pivot g¹ slotted at the upper
end to receive a wire k, the other end of which wire is made fast to the wall
of the room, by preference this wire is of German silver. i is a screw attached
to the lower end of the lever for purposes to be described; m is a spring
attached to the lever G and pressing against the side of a box H which
contains the whole of the apparatus, its object being to keep the wire stretched
to its full extent, J is a lever having a hole near its upper end to receive a
small pin n, which is attached to a tilting weight K. Both the lever G and
the lever J are secured to the box by pins passing through near their ends
and allowing them to work freely. The tilting weight K supports a falling
weight L which is perforated to receive a rod p connected with the crank of
a bell wire, or a cord or wire of any kind may be used. M is the dial shewing
the different degrees of temperature, the hand of which is moved by a crank r
connected by link with the lower end of the lever G and operated by the
expansion or contraction of the wire k.
By a second arrangement of the same modification a lever t, shown in
dotted lines in Figure 18, is attached to the axle of the index hand, and
having the axle loosely revolving in it, the outer end of this lever rests on the
teeth of the upright lever u with its lower end resting on a knife edge u³, or
revolving on a pivot, in this position it remains until a pin in the end of the
index hand (see dotted lines) by the partial revolution of the same comes in
contact with the lever t, moving it upwards and disengaging it from the
teeth of the lever u which being unsupported falls over, and by any convenient
arrangement gives the alarm, or the lever t may be made to rotate on ivory,
glass, or.other non-conductors, and by the movement communicated to it by
the index hand may be brought into contact with the poles of an electrical
battery, and by means of electricity communicates the alarm.

page_text: The following is the mode of operating of each of the berein-before
described arrangements.
In No. 1 modification the instrument is secured to the wall of a room in
a vertical position, and the spring screwed to any degree of temperature
marked on the scale, the falling lever D is placed in nearly a vertical position
with the short pin projecting through the aperture in the upper end of a
compound spring, and the pin of the falling weight properly attached to the:
bell wire crank, as the temperature of the room increases or rises, the upper
end of the spring gradually travels out or deflects until it detaches itself from
the pin in the end of the falling lever, which being unsupported immediately
falls upon the bent lever, which by the action communicated to it detaches
itself from the pin in the falling weight, which being thus left unsupported
also falls, and by means of a string rings the bell, or if the falling lever be of
sufficient weight in falling it may be connected by a strong wire or chain
immediately to the bell wire crank, and so ring the bell without the assistance
of the bent lever and falling weight.
In No. 2 modification the spring is screwed to the required degree of
temperature, and the pin from the tilting platform passed through the
aperture in the upper end of the compound spring, the marble or other
weight is placed on the top of the tilt platform which is held in place by the
pin and spring before mentioned. As the temperature of the room rises the
spring travels out and detaches itself from the pin, when the tilt platform
immediately drops and allows the marble to fall down the tube, coming in
contact with a lever arranged in the manner shewn and described in my said
former Specification, and so starts the bell.
In No. 3 modification the upper end of the compound spring is screwed to
the required degree of temperature, and the lower end connected to the
handle of the weight which rests on its lower side on a knife edge and
connected properly to the well wire. On the increase of the temperature in
the room the compound spring deflects and detaches itself from the pin in
the weight, which then falls, and in doing so rings the bell.
In No. 4 modification the long metal wire or German silver wire is attached
by one end to the wall and by the other end to the short arm of the lever,
the handle of the first weight placed so that it does not quite come in contact
with the short arm of the second lever, the long arm of which is attached to
the second weight by having its pin passing through the aperture in the
lever. As the temperature increases the short arm of the first gradually
rises and the long arm falls with a corresponding increased ratio until the
first weight comes in contact with the short arm of the second lever which it

page_text: presses down, rising in an increased ratio the long arm which soon frees itself
from its supporting pin of the second weight, which being unsupported on the
knife edge falls over and rings the bell.
In the fifth modification the compound spring is screwed to the required
temperature, and the lever with its two weights properly balanced and
adjusted and connected by its hooked end to the aperture in the end of the
compound spring, the sliding ball or weight properly connected by a chain or
cord to the bell crank, as the temperature of the room rises, the compound
spring deflects and frees itself from the hooked end of the lever, allowing its
long arm to fall, and in doing so the sliding weight also falls, moving along
the lever to its lower end, and being connected to the bell crank by means of
a chain or string rings the bell.
In the sixth modification, by the expansion of the wire, the upper end of
the lever G is allowed to move backward, and its lower end by the pressure of
the spring m is with the screw attached to it forced forward, and the screw
touching the lower end of the lever J releases it from the pin n attached to the
tilting weight K. This weight at once allows the weight L to fall, and this
being connected with the crank of the bell wire gives the alarm, or the
spring m, or its equivalent may be placed at the other side and lower end of
the lever G and produce the same result; or the lever t may be placed in
contact with the falling lever u, and on being moved by the index hand is
severed and thus allows the lever u to fall and give the alarm; or the lever t
may be made to connect with the positive pole of a battery, and the index
hand with the negative pole, and thus form an electrical current and so com-
municate the alarm.
Having now described and particularly ascertained the nature of the said
Invention, and the manner in which the same is or may be used or carried
into effect, I would observe in conclusion that what I consider to be novel
and original, and therefore claim as the Invention secured to me by the
herein-before in part recited Letters Patent is,-
First, the peculiar combination and arrangement of plates, compound,
straight, and curved springs, adjusting screws, scale, falling lever, and pin,
bent lever, and falling weight, operating together, substantially in the manner
and for the purpose herein-before described in reference to modification
No. 1.
Second, the peculiar combination and arrangement of compound, straight
and curved springs, adjusting screw, scale, pin, and trip platform, tube
and marble or weight acting together, substantially in the manner and fo
the
purpose herein-before described in reference to modification No. 2.

page_text: Third, the peculiar combination and arrangement of compound straight
spring, adjusting screw and scale, falling weight and pin, acting together, sub-
stantially in the manner and for the purpose herein-before described in
reference to modification No. 5.
Fourth, the peculiar combination and arrangement of wire levers, adjusting
handle, and scale weights and pins, all working together, substantially in
the manner and for the purpose herein-before described in reference to modi-
fication No. 4.
Fifth, the peculiar combination and arrangement of compound, straight,
and curved springs, adjusting screw, scale lever, with fixed and moveable
weights, all acting together, substantially in the manner and for the purpose
herein-before described in reference to modification No. 5.
Sixth, the peculiar combination and arrangement of wire levers, pin-
adjusting screw, falling weight, tilting guide for same, dial and index hand
operating together, substantially as and for the purpose herein-before described
in reference to modification No. 6.
Seventh, the peculiar combination and arrangement of index hand, lever t
and tilting lever u, operating together as and for the purpose herein-before
described in reference to Figure 13 of the Drawings.
Eighth, the establishing an electric circuit by the aid of the lever * and
index hand, as and for the purpose herein-before described in reference to
Figure 13 of the Drawings.
In witness whereof, I, the said John Henry Johnson, have to this my
Specification hereunto set my hand and seal, this Thirteenth day of
November, One thousand eight hundred and sixty-six.
J. HENRY JOHNSON. (L.B.)