US2967571A - Fire extinguisher with insulated pump - Google Patents

Description

Jan. 10, 1961 w. M. HAESSLER 2,967,571

FIRE EXTINGUISHER WITH INSULATED PUMP Filed Feb. 24, 1959 2 Sheets-Sheet 1 26 Tluzl.

24 2o A 22 3 /3 .',':i 4 4644 a ,43 j 7 47 l N V E N TO R #491 men/{4555452 W ATTORNEY 2 Sheets-Sheet 2 W. M. HAESSLER Jan. 10, 1961 FIRE EXTINGUISHER WITH INSULATED PUMP Filed Feb. 24, 1959 United States Patent 2,967,571 EXTINGUISHER wrrn INSULATED PUMP Walter M. Haessler, Chatham, N.J., assignor to The Fyr Fyter Company, Dayton, Ohio, a corporation of Filed Feb.'24, 1959, Ser. No. 794,909

1 Claim. (Cl. 169-33) The present invention relates to fireextinguishers and particularly to an improved pump type liquid charged 'fire extinguished having a corrosion minimizing construction.

The usual pump type fire extinguisher includes a shell or container with a pump extending downwardly into the container which is filled to the desired level with a liquid fire extinguishing agent such as water or a suitable chemical. The fire extinguishing agents are generally electrically conductive materials. By reason of the use of metals or" different composition in the construction of the extinguisher, galvanic currents are often set up between the pump and the shell causing galvanic corrosion which may result in pits extending through the shell and leakageof the fire extinguishing agent. Further, even though leakage does not occur as a result of the corrosive action,..the fire extinguisher liquid may become discolored andmay stainobjects upon which it is discharged.

In US. Patent 2,702,600 issued February 22, 1955, to Scott Allen, and assigned to the assignee of the present application, there is shown a liquid charged fire extinguisher pressurized by a gas cartridge and in which electrical insulating means are provided between the shell of the extinguisherand the high pressure gas cartridge to interrupt the electrical circuit between the shell and the pressurized cartridge and thus minimize corrosion. In the construction of the patent, the gas cartridge is wholly positioned within the container.

,In the present construction the pump extends downwardly into the fire extinguishing liquid contained in the shell of .the extinguisher while the handle and top end of the pump extends upwardly through the top of the extinguisher. The pump is used to expel the fire extinguishing fluid in the example shown, alternatively, the pump might be used to develop air pressure within vthe shell of the extinguisher to expel the fire extinguishing fluid.

The present invention provides an improved pump type liquid,- charged fire extinguisher in which electrical non-conducting material is used for the support of the pump with respect to the shell so as to prevent the flow of galvanic currents between the pump and the shell.

The construction is advantageous in that a simplified construction is provided readily lending itself to low cost and high production manufacture. It should be kept in mind that extinguishers of this type are very competitive in price and performance and the saleability of the extinguisher depends to a great extent upon even slight improvements in the construction thereof as compared to the construction of competitive models.

An object of the invention is to provide a pump type fire extinguisher for liquid fire extinguishing agents in which the extinguisher is simple and economical in manufacture, efiicient in operation and durable in use.

Other objects and advantages of the invention will be apparent from the following description and from the accompanying drawings, which show, by way of example, an embodiment of the invention.

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In the drawings:

Fig. 1 is a vertical sectional view of a pump fire :extinguisher in accordance with the invention.

Fig. 2 is a top view of the fire extinguisher shown in Fig. 1.

Fig. 3 is an enlarged view of the top portion of Fig. 1, the enlarged view being used to portray the parts in greater detail.

Referringto .the drawings, there is shown in Fig. 1, a fire extinguisher 1 including a container or shell 2 adapted to receive a liquid fire extinguishing agent such as water or any other liquid suitable as a fire extinguishing agent. Thecontainer 2 is closed by a top 4 having at one end thereof a-carrying handle 5. A pump 6 extends upwardly from the top 4 of the extinguisher and has an outlet 7 on one side of its upper end. A hose 9 is attached to the outlet 7 and terminates in a nozzle 10.

The container 2 may be constructed of any suitable material such as copper, galvanized steel, stainless steel or other conventional materials. The extinguisher as shown 'is of the type having a capacity of about 2 /2 gallons of fluid, although a container of any desired size alternatively may be used. A fillingopeningin the top .of the container 2 is closed by a removable cover '11 which may be of any suitable construction so that it is retained in position. The container 2 may be madeof sheet material formedin cylindrical shape by usual construction methods and having a bottom '12 attached at the lower end of the shell. The joint between the top and bottom may be seamed as illustrated at 13 and if desired may be soldered to assure a more leak proof con? struction. It, should be noted, however, that the container shown is not under pressure andneed only'be made sufiiciently strong to hold the fluid at atmospheric pressure The top 4of the. container 2 is apertured as indicated at 14 to receive the pump assembly 6, the top 4 providing the sole support for the pump assembly.

The pump 6 includes a cylinder 15 within which is reciprocated a piston 16. The cylinder 15 has its lower end protected by a strainer 17. Inwardly of the strainer is a foot valve seat 18 which may be made of polyethylene or equivalent material providing a suitable seat. A foot valve member 20 having a tapered end portion 21 is adapted to engage the seat 18 The sidewall of .the body of the foot valve member 20 may be provided with a spider construction having legs 22 adapted to slideably engage the inner surface of the cylinder 15 and provide spaces between the valve member body 20 and the cylinder wall for the upward movement of'fluid entering into the strainer 17 and passing the valve seat 18. At the upper end of the cylinder 15 and threadedly engaged therewith is an extension member 19 adapted to receive; at its upper end a bonnet or'cap member 29. The extension 19 is made with a somewhat thicker wall than, the cylinder 15 for greater rigidity and strength ,for the mounting of the outlet 7,. The bonnet member 2.0 :has an inwardly turned flange 21 to hold a packing including a head gasket 22 backed up by a U-cup packing gasket 24.

The head gasket 22 may be made of polyethylene and the U-cup packing 24 may be made of a rubber based material or other suitable material having the desired yielding qualities to provide a good seal. It should be noted that the head gasket 22 is made of an outer diameter such as to overlie the upper end of the cylinder extension 19 so that, when the bonnet member 20 is threadedly engaged with the top of the cylinder extension, the head gasket 22 is compressed between the end of the cylinder extension and a shoulder 25 on the inner surface of the bonnet member 20.

The piston 16 of the pump 6 is adapted to be recipro member 27 threadedly engaged withthe upper end of the piston 16. At the lower end of the piston 16 is a piston valve seat member 29 threadedly engaged with the lower end of the piston 16. The piston valve seat member 29 is recessed at its outer surface to receive a packing 30. The lower end of the piston valve seat member 29 is turned inwardly as indicated at 31, the upper surface thereof being tapered as indicated at,32 to provide a seat for a ball valve member 34 made of glass, plastic or any other suitable material. An aperture 35 is formed at the lower end of the piston 16 a portion of the wall of the aperture being turned inwardly as to form a stop 36 preventing upward movement of the piston ball valve 34.

The diameter of the piston 16 is made somewhat smaller than the inner diameter of the cylinder 15 so as to provide a space 37 for fluid and for a spring 33 extending approximately one-fifth of the length of the cylinder. The spring 38 normally falls to the bottom of the space between the piston 16 and the cylinder 15 and rests on the upper surface of the valve seat member 29. The spring 38 is for the purpose of cushioning the upward movement of the piston 16 as it is reciprocated, the upper end of the spring 38 contacting the lower surface of the head gasket 22 at the top of the stroke of the piston. The hose 9 is attached at one end to the outlet 7, a tight connection being made by a clamp member 40 secured in position by a screw or bolt 41. In order to protect the hose 9 its upper end is encased in a spring 41 which has its inner end 42 formed around the bolt 40.

In accordance with the invention an electrical nonoonducting material is used for the sole support of the pump 6 with respect to the shell 2 so as to prevent the flow of galvanic currents between the pump and the shell. The electrical non-conducting construction includes an insulating plate 43 having an aperture therein closely fitting the external surface of the cylinder extension 19, the insulating plate 43 is maintained in position over the extension 19 by being secured between a pair of annular nuts 44 and 45 threadedly engaged around the lower end of the outer surface of the extension 19. The insulated plate 43 is apertured adjacent its outer edge to receive screws 46 or other suitable means such as rivets extending therethrough and through aligned openings in the top 4 of the container and then into a reinforcing plate 47 which may be if desired, soldered or otherwise secured to the underside of the top 4.

The insulating plate 43 may be made of any suitable electrical non-conducting material and may have a laminated fabric base impregnated with a phenolic resin or a synthetic resin, or nylon, phenol-formaldehyde, urea formaldehyde, melamine, Teflon, rubber, fiber glass, asbestos, or micaeither alone or bonded with any suitable resin. Also, the plate 43 may be made of porcelain, ceramic, glass, or any other suitable material providing the desired electrical non-conducting characteristics and which is of sufiicient strength to provide the sole support for the pump 6.

In the operation of the fire extinguisher in accordance with the invention as the pump handle 26 is raised, the

fluid is drawn through the strainer 17, past the foot valve seat 18 thence upwardly past the foot valve member 20 into the space behind the piston 16. Upon a downward movement of the piston 16 the foot valve member 20 is seated and the ball valve member 34 unseated allowing the fluid to pass into the space within the piston 16 above the ball valve member 34 and outwardly through the opening 35 into the space between the piston 16 and the wall of the cylinder 15. Upon the next upper movement of the piston 16 the fiuid within the space between the piston 16 and the cylinder 15 is forced through the outlet 7 into the hose 9 and outwardly through the nozzle 10. I

Galvanic potentials normally will be produced if the metal of the pump is different from the metal of the shell, the electrolyte being the fire extinguishing agent. However, by reason of the insulating plate 43 no galvanic currents will flow and there will be no resultant pitting of the pump or the shell. i

From the preceding description it will be seen that the present invention provides a pump type fire extinguisher including means for minimizing corrosion of the parts thereof by interrupting the galvanic currents which would normally flow between the pump and the cylinder wall.

While the invention has been described and illustrated with reference to a specific embodiment thereof; it will be understood that other embodiments may be resorted to without departing from the invention, therefore, the form of the invention set out above should be considered as illustrative and not as limiting the scope of the following claim.

I claim:

In a fire extinguisher of the type used for dispensing an electrically conductive fire extinguishing agent, the extinguisher including a metallic container and a pump ex tending through an opening in the top of the container down into the container in contact with the electrically conductive fire extinguishing agent normally stored therein, and the pump is provided with a hose having a nozzle at the outer end thereof for the discharge of the fire extinguishing agent, the pump adapted to be reciprocated to pump the fire extinguishing fluid from the container, the improvement wherein an electrical insulating member is provided in the wall of the container providing the sole supporting means for the pump, the electrical insulating member having an aperture, the pump received in the aperture, a pair of annular nuts threadedly engaged around the wall of the pump and securing the wall of the aperture of the electrical insulating member therebetween, a reinforcing plate for the opening in the top of the container, and means bringing in clamped engagement the edge of the electrical insulating member, the wall of the opening in the top of the container and the reinforcing plate, thereby providing the mounting for the pump whereby corrosion of the fire extinguisher is minimized.

References Cited in the file of this patent UNITED STATES PATENTS Iddings et al Aug. 21, 1945

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