US1956744A - Fire extinguisher - Google Patents

Description

Patented May l, 1934 FIRE EXTINGUISHEB.

John M. Melick, Cresskill, N. J., assignor to Ball Telephone Laboratories,

Incorporated, New

York, N. Y., a corporation o1 New York Application June 30, 1932, Serial N0. 620,082

2 Glaims. (GI. 169-31) This invention relates to fire extinguishers and more particularly to fire extinguishers of the type in which a fire extinguishing medium is expelled from a. tank by pressure re1eased from a.

cartridge within the tank.

'I'he obje ct of this invention is to prevent freezing 'at the outlet end of the cartridge ca.se during the escapement of fluid from the cartridge case into the tank.

A feature of this invention resides in a. stem for puncturing the cacrtridge which serves as an aspirator a.nd permits sufficient circulation of the fire extinguishing medium around the puncturing portion cf the stem and across the outlet end of ehe cartridge case to prevent freezing a.t the point at which the fluid under pressure is esc aping into the tank.

In the drawing, Fig. 1 is a side elevational view partly in section of a, fire extinguisher embodying this invention;

Fig. 2 shows a, fragment of the upper portion of a cartridge case in section am]. a. fragment 01' a stem puncturing the cartridge case;

Fig. 3 is a. view in section ta.ken 011 the line 33 in Fig. 2 and shows a fragment of the upper portion of the cartridge case and a fragment of the stem puncturing the cartridge case; and

Fig. 4 is an exploded view part1y in section of a cartridge case, a, coupling for holding the cartridge case suspended within the main tank of the extinguisher from a. screw cap of the tank a.nd gaskets for preventing the entrance of meisture 130 end and neck portions 01 the cartridge case.

Fire extinguishers of the type shown in Fig. 1 are usually filled with a chemical in liquid form which serves as a fire extinguishing medium. T0 expell the fire extinguishin chemical from the tank with sufiicient force so reach a. fire, gas he1d under pressure within a, cartridge case supported within the tank, is released from the cartridge case and a11owed 130 escape into the sank.

There are some instances, however, when in putting out a, fire the use of fire extinguishing chemical is fo1md undesirable. 'I'his is partieularly true in the extinguishment of fires 00cm- Iing among delicately adjusted mechanical am].

electrical elements or comparatively close networks cf wires such, for instance, as found in 50 telephone equipment in central stations. When fire extinguishing chemical is used in xtinguishing a. fire occurring among telephone relays switches or wire networks, considerable damage is done 170 the apparatus by reason of the 001- 55 rosive efiects of the chemical on the comparative- 1y closely spaced contacts and the inherent adhesive properties of the chemical in sticking to the apparatus parts upon which it happens to fall. In addition to the damage caused by the fire a.nd the corrosive effects of the chemical fire extinguishing medium, there is also a considerable 10ss due to the time required in removing the chemical from the apparatus a.nd reconditioning the apparatus for service again. It has therefore been found advisable in extinguishing fires in some instances to use water as the fire extinguishing medium in plane of a chemical. When wa.ter is used as the fire extinguishing medium, the parts to which it is applied and which are not damaged by fire may be quickly dried out and restored 120 operable condition.

A cartridge of carbon dioxide under pressure has been found a. satisfactory mequm for crea.ting sufi'icient pressure within a tank of water to expe1l the wa'uer from the tank. Applicant has found, however, by actual experience that when s. comparatively sma1l puncture is made in a ca.rtridge case containing carbon dioxide a.nd the carbon dioxide is allowed to escape through the aperture into the water in the tank, freezing occurs at the point 01 puncture. 'I'he freezing at the point of escapement of the carbon dioxide from the cartridge case into the water-filled ta.nk results in either complete stoppage of the flow of carbon dioxide into the ta.nk er an intermittent flow and hence either complete cessation 01 the flow of water from the tank 130 the fire or an intermittent fiow so inefiective asto render the fire extinguisher comparaoively useless for the purpose intended.

In the present invention a stem for puncturing the cartridge case is provided which permits suflicient circulation of water or other fire extinguishing medium around the point of puncture in the cartridge case 130 prevent freezing at this point.

For a complete description of this invention, reference will now be had to the various figures in the drawing in which like parts bear 1ike numerals and in which 1 is a comparatively large tin-lined copper tank having an annular base 2, a top portion 3, a. handle 4, a screw cap 5 and an out1et connection 6, across the inner end of which is a perforated platze 7. 'I'he screw cap 5 is screw-threadedly attached to a comparatively 1arge annular filler connection 8 located in the top poruion 3 of the tank 1 and is provided with a comparatively 1arge diameter ring-shaped hau: grip 9 which is connected to the screw cap 5 by spokes 10. The top of the screw cap 5 has an upwardly extending annular centrally 1ocated boss 11 and a tln 12 extending' radially from the boss 11. The boss 11 is internally threaded to receive the smaller externally threaded end-o1 a reducing coupling 13 which is screwed into the threaded boss 11 1mm the underside of the screw cap 5, the larger extemally threaded end 14 of the reducing coupling 13 extending downward from the underside of the screw cap through the filler connection 8 and. towards the interior of the tank 1.

Supported within the tank 1 is a cartridge case 15 containing a charge of carbon dioxide under pressure. 'Ihis cartridge case 15 is a bottleshaped casing cf steel having an enlarged lower end portion, an externally threaded neck portion 16 and an upper reduced e nd portion 17. The Walls of the cartridge case 15, as shown in section in Fig. 4, are comparatively thick. The wall, however, at the extreme upper end of the reduced end portion 17 is considerably reduced in thickness as shown at 18 in Figs. 2, 3 and 4 to provide a comparatively thin wall section which may be punctured when it is desired to allow escapement of the carbon dioxide from the cartridge case 15 to ehe tank 1. T0 prevent corrosion 015 the steel cartridge case and electrolytic action between the st eel of the cartridge case and the inner wall sur1'ace of the tank 1 which would result in pitting of the steel Wall of the cartridge case and finally a.llow escapement of the carbon dioxide from the cartridge case into the tank 1, the enlarged portion 01 the cartridge case 15 is enclosed in a. lead shirt as shown in section at 19 in Fig. 4. 'Ihis lead shirt encloses the whole of the lower section of the cartridge case 15 and extends up to the threaded neck portion 16. The threaded neck portion 16 and reduced end 17 and the outer surface of the reduced wall at 18 are tinnecl to prevent corrosion of these parts.

The cartridge case 15 is suspended within the tank 1 from the reducing coupling 13 by means of a. sleeve 20 which is internally threaded at 21 to engage the externally threaded larger end 14 of the reducing coupling 13 and internally threaded at 22 to receive the externally threaded neck portion 16 of the cartridge case 15. An annular inwardly extending beveled shoulder 23 is provided about midway of the ends of sleeve 20 to form a. receptacle for the reduced end portion 17 of the cartridge case 15. Between the shoulder 23 and. the interiorly threaded end 21 are two comparatively lauge side outlet ports 2424. A cap gasket 25 of lead, apertured at the top, is fitted over the reduced end 17 of the cartridge case 15 and compressed against the internally extending annular beveled shoulder 23 of the sleeve 20 to prevent moisture from gaining 9.ccess to the reduced end portion 17 of the cartridge case 15. The lower portion of the sleeve 20 is flared out in the form of a hell at 26 and provided with an outwardly extending annular offset 27 to accommodate the lower end of the neck portion o1 the cartridge case 15. 'Io prevent moisture Irom gaining access 130 the threaded neck portion 16 0f the cartridge case 15 in the region of the lower portion 01 the sleeve 20 a rubber ring gasket 28 is slipped over the neck of the cartridge case 15 and compressed against the inner wall surface of the annular offset 27 of the sleeve 20.

'Io puncture the cartriclge case 15 ab the reduced wall portion 18 a. stem 29 is provided. The stem 29 which is adapted 120 move longitudina.lly within the reducing coupling 13, comprises a. shank portion 30 which extends upward through the reducing coupling 13 to the outside o1! the extinguisher and an enlarged lower cylindrical end 31 which extends downward within the tank. The lower portion o! the enlarged' lower cylindrical end 31 01 the stem 29 is chamfered on opposite sides and cut down to form a spade end 32 having three spaced pr0ngs in parallel, the central prong being about. twice the length of the other two and Iorming a cylindrica.l puncturing pin 33 for puncturing the cartrldge case 15 at the point 18 where the wall of the cartridge case 15 has been reduced in thickness. A groove 34 is-provided in one side of the puncturing pin 33 to allow escapement of the carbon dioxide from the cartridge case 15 when the puncturing pin 33 is thrust through the reduced wall portion 18. The groove 34 does not extend the full length of the puncturing pin 33 but starts at a point slightly above the lower extremity of the pin and extends upward into the curved portion of the chamfer as shown in Figs. 1, 2 and 3. When the puncturing pin 33 is driven through the reduced wa.ll portion 18 o1 the cartridge case 15 as shown in Figs. 2 and 3 it makes a round hole in the reduced wall portion 18 and is thrust far enough through so tha.t the full round solid end of the puncturing pin extends below the inner surface of the reduced Wall portion 18 and the lower end of the groove 34 is within the cartridge case 15. Carbon dioxide within the cartridge case 15 then escapes from the cartridge case 15 into the tank 1 by way of the groove 34 and the side outlet ports 24-24 01" the sleeve 20. The two outside prongs 3535 on the spade portion 32 of the stem 29 rast on the top of ehe carbridge case 15 and limit the extent of thrust of the puncturing pin 33 through the reduced Wall portion 18 cf the cartridge case 15 and in cooperation with the puncturing pin 33 form two arch-like channels on opposite sides of ehe puncturing pin 33 for circulation of the wa.ter or other fire extinguishing medium across the top of the cartridge ca.se 15. Between the enlarged lower cylindrical end 31 and the shank portion 30 of the stem 29 is an outwardly projecting annular shoulder 36 which bears against the inner Wall surfa.ce of the larger end 14 of ehe reducing coupling 13 and the inner Wall surface of an inwardly projecting annular shoulder 37 provided in the upper portion of the sleeve 20 as shown in Fig. 1.

011 the outer end of the stem 29 is an impact knob 38 to receive a. blow administered to the stem 29 when the puncturing pin 33 is to be thrust through the reduced wall portion 18 01 the cartridge case 15. The impact knob 38 has an inverted cone-shaped upper portion terminatmg in a cylindrical lower portion which is longitudinally bored to accommodate the outer end.of the shank 30 of the stem 29. Laterally projecting from the lower cylindrical portion of the impact knob 38 is a lug 39 and dir'ectly below the lug 39 and extending in the same direction is a pair of spaced fingers 40, only one of which is shown in Fig. 1. The lug 39 is beveled on its undersurface and cooperates with a spring pressed holt 41 supported by a bracket 42 on the fin 12 to hold the stem 29 in its projected position and driven through the reduced wall portion 18 of the cartridge case 15. The spaced fingers project on opposite sides of the bracket 42 and prevent rotation of the stem 29.

In operating the fire extinguisher a. blow is delivered to the impact knob 38 sufiicient to drive the stem 29 inward. of the tank 1. This may be conveniently done by turning the extinguisher upside down and driving the impact knob 38 against a floor surface. The stem 29 thereby is driven inward of the tank 1 and the puncturing pin 33 of the stem 29 is thrust through the reduced wal1 portion 18 0f the cartridge case 15. The lug 39 on the impact knob 38 is driven agdinst the spring pressed holt 41 and causes suflicient displacement of the holt 41 to allow the 1ug 39 to pass. When the lug 39 passes the holt 41 the spring pressed holt 41 again resumes its normal position and prevents withdrawal of the puncturing pin 33 from the cartridge case 15. Carbon dioxide then begins to escape from the cartridge case 15 by way of the groove 34 in the puncturing pin 33 and passes through one of the ports 24 of the sleeve 20 into the tank 1 and exerts sufiicient pressure in the tank 1 to expe1 the water from the tank, the water finding an outlet through the apertured plate 7 and outlet connection 6 from whence it flows through the hose 43 and nozzle 44 with sucient force 130 be directed to the fire.

When the carbon dioxide begins 130 escape from the cartridge case 15 by way 01 the groove 34 in the puncturing pin 33 it sets up an aspirator efiect around the point of puncture in the reduced wall portion 18 and Starts a cixculation cf water across the point of puncture, the water being drawn through the port 24 opposite to that which faces the groove 34 and passing across the punctured end of the cartridge case 15 and around the puncturing pin 33 by way cf the arch-like channels formed. by the outer prongs 3535 and the puncturing pin 33. Circula.tion of water around the puncturing pin 33 continues as long as the carbon dioxide continues to escape and prevents freezing at the point cf puncture.

What is claimed is:

1. In a fire extinguisher comprising a tank comtaining water and a. cartridge of compressed fluid supported within the tank, a stem ha.ving a pin portion to be thrust into said cartridge to a11ow escapement of said compressed fiuid into the tank, and a pair of fins projecting from said stem, said fins projecting parallel to said pin portion and spaced therefrom to form channels for circulation of the water in the tank around said pin when sa.id pin is thrust into said cartridge and the compressed fluid is escaping into the Trank.

2. In a fire extinguisher comprising a tank comtaining water, and a cartridge containing fiuid under pressure supported Within the tank, a rnovable stem having a free end pin portion to be thrust into said cartridge, said pin portion having a. recess formed in one side providing a channel for escapement of the fiuid from said cartridge, and fins projecting from said stem parallel to said pin and spaced from said pin to limit the extent of thrust of said pin into said cartridge and forming in cooperation with sa.id pin and an end 01 said cartridge, channels for circulation of the water in said tank around the pin portion and across an end of said cartridge.

JOHN M. MELICK.

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