1. * GB780071 (A)
Description: GB780071 (A) ? 1957-07-31
Fire-extinguishing apparatus
Description of GB780071 (A)
PATENT SPECIFICATION
780,071 Date of Application and filing Complete Specification: May 25,
1954.
Complete Specification Published: July 31, 1957.
Index at acceptance:-Class 47, A4.
Enternational Classification:-A62c.
COMPLETE SPECIFICATION
Fire-Extinguishing Apparatus I, FOKKE WILHELMUS VAN DER LAAN, of Dutch
Nationality, of 73, Rozenlaan, Breda, Holland, do hereby declare the
invention, for which I pray that a patent may be granted to me, and
the method by which it is to be performed, to be particularly
described in and by the following statement: -
This invention relates to fire extinguishing apparatus.
According to the invention there is provided a fire extinguisher
comprising a flat circular closed tank partly filled with a liquid and
formed from a pair of shaped annular discs secured directly together
at their outer edges, an axially extending discharge nozzle mounted
centrally of the tank in one of said discs, a sealed cartridge
containing a foaming agent supported within said tank, and rotary
means operable to cut through said cartridge and to establish
communication between the tank and the discharge nozzle.
The aforesaid rotary means may comprise a tubular arm mounted for
rotation in the other tank disc and about the tank axis, and
communicating at its inner end with the discharge nozzle, said arm
carrying a knife for cutting through the cartridge and having an open
outer end immersible within the liquid in the tank. To ensure this
immersion, the outer end of the tubular arm may be formed with two or
more branches extending towards opposite sides of the tank.
The discharge nozzle Imay normally be closed by a perforable seal and
said nozzle may be formed at its outer end with a knife edge, the

2. nozzle being slidable axially to, cut through the seal. This movement
may be effected by a rotatable handle provided with cam serrations and
which, on operation, slides the tubular member axially, said member
being secured to the nozzle. In its axially adjusted position the
tubular member is free to rotate gravitationally so that it can cut
through the foaming agent cartridge to discharge said agent into the
liquid in the tank.
This arrangement ensures 'that the nozzle [Price 3/6] seal is broken
before the cartridge is cut through.
An embodiment of fire extinguisher according to the invention is
illustrated by 50 way of example in the accompanying drawings,
wherein: Fig. 1 shows the fire extinguisher in axial section; and Fig.
2 is a front view of the fire extinguisher to a smaller scale.
The fire extinguishing apparatus shown in the drawings comprises a
circular tank 1 having in diametrical cross-section approximately the
shape of the figure 8 and formed 60 from two annular discs 2, 3
secured together at their edges 29. To one side of the median plane
between the discs and extending axially of the tank is a discharge
nozzle 4, while arranged radially outwardly from said nozzle 65 and
within the tank is a holder 5 for a cartridge 12 containing a foaming
agent. The central parts 6, 7 of the discs 2, 3 are apertured to form
axially spaced bearings, the nozzle 4 being supported in the bearing 7
70 for both rotary and longitudinal movement.
The cartridge holder 5 is formed by a pair of aligned tubular members
8, 9 secured to and extending inwardly from the respective discs 3, 2.
The disc 2 is apertured to provide for insertion of the cartridge 12
and said aperture is thereafter closed by a removable cap 10.
Abutments 13, 14 of any convenient resilient material are secured to
disc 80 3 and cap 10 so as to project within the tubular members 8, 9
said abutments engaging the opposite ends of the cartridge and thus
preventing it from becoming damaged during transit. 85 Mounted within
the tank 1 for rotation about the tank axis is a tubular arm 15 which
towards its outer end carries a knife 11 adapted to pass between the
inner ends of the tubular members 8, 9 and so to cut through 90 the
cartridge wall and release the foaming agent. At its inner end the arm
15 cornNo. 15374154.
780,071 municates with a chamber 16 formed in a hub part 15a of said
arm and communicating at one end with the bore 17 of the discharge
nozzle 4. The hub part 15a is journalled at one end in the bearing 6
and at its other end is secured to the discharge nozzle so that arm 15
and nozzle 4 are rotatable as a unit. The outer end of arm 15 is
formed with branched portions 18 of which any convenient number, e.g.,
two, may be provided.
In Fig. 1 only the inner ends of the branches are shown, but they are

3. of a length, i.e., a few inches, enabling them to extend into the
liquid contained in the tank, the liquid level being indicated at V.
At its outer end the discharge nozzle 4 is provided with a circular
knife edge and this nozzle end is normally closed by a foil disc 20
which is held against the nozzle by 20a cap 19. The foil disc 20 is of
such a strength that it cannot be broken by the gravitational weight
of the nozzle 4 and an arm 15, but only when pressure is exerted
therein by the handle 23 acting through the cam 25faces provided on
the heads 21 and 20 described below. That end of chamber 16 remote
from the nozzle 4 is closed by a plug 21a secured to the hub 15a and
formed at its outer end with a head 21 having a radially serrated end
face forming a series of cams.
Beyond the plug 21a is a spindle 22 provided with a handle 23 at its
outer end and with a head 24 at its inner end, said head 24 being
formed on its end face with cam serrations complementary to and
co-operable with the serrations on the head 21. The spindle 22 is
rotatably mounted in a sleeve 34 carried by the disc 3 and is locked
therein by a gland so as to be held against axially outward movement.
Mounted externally of the tank and in the median plane between the
discs 2, 3 is a tyre enabling the tank to be easily rolled to any
required position. At that side opposite the discharge nozzle a ring
28 is secured to disc 3 by welded arms 31. Suspension brackets 33
having eyes 32 are provided on the tank to enable the extinguisher to
be hung on a wall hook or the like.
The operation of the extinguisher described is as follows, the tank
having previously been filled with liquid to the level V, the
cartridge inserted into the holder 5 and the latter closed by the cap
10.
To cut through the cartridge 12 the handle 23 is rotated to turn the
head 24 relatively to the head 21, whereby the plug 21a is moved
axially towards the right (Fig. 1) through a distance corresponding to
the height of the serrations on said heads. The arm 15 and the
discharge nozzle 4 are thus also moved towards the right and the knife
Age on said nozzle cuts through the foil disc to provide an opening
for the discharge of the fire extinguishing liquid. The height of the
serrations is less than the distance between the knife 11 and the
inner end of the tubular holder member 9 so that in this axially
adjusted position of the arm 15, the knife is free to pass between the
holder members 8, 9 to cut through the cartridge. This movement of the
knife, effected by rotational movement of the arm 15 on which it is
mounted, is possible in the axially adjusted position of said arm
because the latter and 75 the discharge nozzle are now free to turn
gravitationally relatively to handle 23 and head 24. Consequently. if
the tank is rotated, the knife 11, at some point during said rotation,

4. cuts through the cartridge 12 to dis-80 charge the foaming agent into
the liquid in the tank and the end of at least one of the branches 18
dips into the liquid mixture.
The high pressure of this mixture under the action of the foaming
agent in the liquid 85 causes the mixture to pass through the arm to
the chamber 16 and thence outwardly through the nozzle 4. The
extinguisher will now continue to discharge the foam mixture
regardless of the position into which it is 90 turned, as the arm 15
will now always remain in a depending position with at least one of
the branches 18 in communication with the mixture.
While the extinguisher is not in use it may 95 be hung, for example in
the position shown in Fig. 2, on a wall hook or the like by means of
one of the suspension brackets 33, the nozzle 4 facing the wall and
the ring 28 thus being positioned so that it can be easily 100 grasped
when the extinguisher is required.
The arm 15 with the knife 11 may be locked in an upstanding position
as shown by means of a lead seal fixed to the handle 23 and adapted to
retain said handle in a desired 105 position, said seal being broken
by rotation of the handle 23 when the extinguisher is to be used. The
handle is conveniently arranged so as to be radially aligned with said
arm, thereby providing an indication of the position of the arm. Owing
to the fact that the foil disc 20 cannot be broken by the
gravitational weight of the nozzle 4 and arm 15, and to the fact that
the head 21 can only rotate after the cams on heads 21 and 24 have 115
been separated by relative rotation thereof, the arm 15 will remain in
its initial position until the above mentioned lead seal has been
broken and the handle 23 rotated to break the foil disc 20. Opposite
the discharge 120 nozzle may be located the open end of a pipe fixed
to the wall, the purpose of which is to receive the discharged foam
mixture if the extinguisher should be set in operation while on the
wall, and thereby avoiding damage to 125 the wall and floor.
When the extinguisher is removed from its wall position it can easily
be transported to any position where it is to be used by rolling it on
the tyre 30. During this movement 130 780,071 the cartridge remains
undamaged due to the closely fitting tubular holder members 8, 9 and
the resilient abutments 13, 14. During transportation, moreover, the
arm 15 remains locked, so that the knife 11 cannot contact the
cartridge. The ring 28 and tyre 30 enable the extinguisher to remain
substantially upright when it is stationary.
The head 21 of plug 21a carries spring10loaded radially arranged pins
25, 26 which, when the nozzle 4 is moved to cut the foil 20, are
projected into a recess. 27, formed in the sleeve 34, and thereby
prevent the nozzle from moving to the left and returning to the
position shown in Fig. 1 while the extinguisher is in use. As the arm

5. 15 is thus freely pivotable when the extinguisher is in use, the
latter can be turned to any position and in any direction without
affecting its operation. The shape of the tank allows for high
pressure of the foam mixture. Until the discharge nozzle foil 20 and
the cartridge are broken, the extinguisher is completely leak proof.
The foil 20, moreover, is located inside the adjacent side plane of
the tank and is thus largely screened from damage. Even if the liquid
in the tank should freeze the contents of the cartridge 12 would
remain unaffected as the latter is secured above the liquid level when
the tank is stored in the position shown in Fig. 2. Furthermore, in
this position, the branches 18 are located above the liquid level V
thus ensuring that the liquid does not escape from the tank during
storage.
The flat form of the extinguisher enables it to be slid beneath
objects such as vehicles or furniture, while in addition it is capable
of floating on a liquid which is burning.
Once it has been set in operation no further control is necessary
other than possibly to move its position. Since the nozzle seal must
be pierced before the knife can be operated to cut through the
cartridge there is no possibility of the foaming agent being released
from the cartridge until the discharge nozzle is open.
While the drawings illustrate an extinguisher comprising a single
tank, it is possible to arrange a number of tanks, each containing a
quantity of liquid and a foaming agent cartridge, to form a battery.
With this arrangement one of the endmost tanks would be fitted with a
discharge nozzle which could be placed in communication with
successive tanks by means of couplings arranged centrally between the
tanks and provided with sealing foils adapted to be successively
pierced by the operation of a common axially extending control member.
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