US3530942A - Fire extinguisher with a clip connected control head - Google Patents

Description

United States Patent FIRE EXTINGUISHER WITH A CLIP CONNECTED CONTROL HEAD 5 Claims, 4 Drawing Figs.

Int. Cl. A62c 13/24 Field of Search 169/30, 31;

[56] References Cited UNITED STATES PATENTS 2,701,660 2/1955 Voorheis 220/46X 2,918,976 12/1959 Peterson 169/31 Primary Examiner-M. Henson Wood, Jr. Assistant Examiner-Michael Y. Mar Attorney-Ernest A. Joerren and Gerald Durstewitz ABSTRACT: A fire extinguisher having a plastic control head which is connected to the neck of an extinguishing agent container by a flat clip having arms which are received by apertures in the neck and lie in grooves formed in the top surface of the control head. The clip and the control head are provided with interferring formations which allow the clip to be withdrawn only when the control head is depressed into the neck sufficiently to render the sealing arrangement between the neck and the head ineffective and allow pressure within the container to vent.

Patented Sept. 29, 1970 Sheet 1 of 2 INVENTOR m mmssu Patented Sept. 29, 1970 FIG.3

INVENTOR nn: R ANSEN FIRE EXTlNGUISI-IER WITH A CLIP CONNECTED CONTROL HEAD BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to apparatus for confining and dispensing fluid medium under pressure, such as portable fire extinguishers and the like, and more particularly to such apparatus having an improved control head locking arrangement enabling low cost construction.

2. Description of the Prior Art practice ln the past, it has been common practic to provide apparatus of the class described with a metal control head which is threaded onto the neck of the container. The cost of the metallic material used for the control heads and the cost of machining these materials have severely limited efforts to reduce the cost of manufacturing this type of apparatus. Copending U. S Pat. application Ser. No. 760,584, now U.S. Pat. No. 3,403,924, filed, September 18, 1968, and assigned to the assignee of this application, describes anarrangement for connecting the control head to the neck which permits the control head to be made of plastic so as to substantially reduce the cost of manufacture.

In the arrangement described in the aforementioned application, two sets of vertically elongated slots are provided in the control head and in the neck and a U-shaped pin is inserted through the slots to lock the control head in place.

The present invention is an improvement over the arrangement of the aforementioned application which further reduces the cost of manufacture and reduces assembly time.

SUMMARY The object of the present invention is to provide apparatus of the class described with an improved threadless control head locking arrangement.

in accordance with the present invention the foregoing object is accomplished by providing in fluid medium dispensing apparatus the combination of a container having a tubular neck member at the top, a removable control head member mounted in the neck for vertical movement between an upper operational position and a lower venting position, means on the members for providing a seal between the members only in the operational position, the control head having a cylindrical lower portion within said neck and a narrow upper portion extending upwardly from the lower portion, the lower portion being provided with an upper surface including a pair of elongated surface 1 areas extending along opposite sides of the upper portion, the neck being provided with an aperture at each end of the elongated areas, and a locking member having a pair of parallel arms each extending .over one of the areas and being disposed in the aperture at the ends thereof.

BRIEF DESCRIPTION OFTHE DRAWING A preferred embodiment of the invention has been chosen for purposes of illustration and description, and is shown in the accompanying drawing, forming a part of the specification, wherein:

FIG. 1 is a fragmentary elevational view partly in section illustrating a fire extinguisher equipped with a control head coupling arrangement in accordance with the present invention.

FIG. 2 is a sectional view taken along the line 22 on P161 FIG. 3 is a sectional view taken along line 3-3 on F l0. 1.

H6. 4 is a sectional view taken along line 4-4 on HO. 2.

DESCRIPTION OF THE PREFERRED EMBODlMENT Referring now to the drawing in detail there is shown a fire extinguisher, by way of example, which generally comprises a metal container provided with a tubular neck 11, a plastic control head 12, a sealing arrangementv 13 forming a seal between the neck 11 and the head 12, a valve 14 in the control head, a syphon tube 15 extending downwardly from the control head 12 into the container 10, and a locking arrangement including a flat U-shaped locking clip 16.

The extinguisher shown herein is of the type adapted to be partially filled with a fluid medium such as water or a dry chemical powder, and then pressurized with a gas for the purpose of forcingthe fluid medium'up through the syphon tube 15 and out through the valve 14 when the valve is opened.

The container 10 is constructed of sheet metal such as stainless steel and has a domed end 17 provided with an opening 19. The container preferably has an elongated shape with the large dimension extending parallel to the syphon tube. The neck 11 is a tubular metallic member and is inserted into the opening 19 and welded to the container to form a gas tight connection.

The body of the control head- 12 is made of a plastic material such as a polymerized formaldehyde, and is formed with a stepped cylindrical lower portion 20 slidably mountedwithin the neck 11, an upper-portion 22 generally having the "shape of a section of a cylinder, an axial bore 24in the portion 20 for receiving the syphon tube 15, and a dischargepassageway 25 in the portion 22 connecting with the bore 24.

The cylindrical lower control head portion 20 "is formed with an upper section 26 and a lower section 27 having a substantially smaller outer diameter.

The discharge passageway 25 includes an axial bore 31 in communication with the bore 24 and a lateral bore 32 intersecting the bore 31. A bore 34 of smaller diameter than the bore 31 extends coaxially with the bore 31 from the intersection of the bore 32 upwardly through the upper surface of the control head.

The valve 14 includes a valve seat 35 formed at the junction of the bores 24 and 31, and a valve member 36 having a head portion 37 positioned in the bore 24 and a stem portion 38 extending upwardly therefrom through the bores 31 and 34 past the upper surface of the control head. An O-ring 40 is' A metal handle 44 is riveted or otherwise rigidly attached to the rear of the upper control head portion 22, and a valve operating lever 45 is pivotally mounted at 43 .on the control head and extends rearwardly over the handle 44. The valve 14 is operated by grasping the lever and the handle in one handand squeezingv The sealing arrangement 13 includes anannular formation 46 projecting inwardly at the bottom of the neck 11 providing a cylindrical surface 47, and an O-ring seal 48 which is mounted in an annular recess 49 formed in the section 27 of the control head to seal against the surface 47.

The upper section 26 of the lower control head portion 20 has an outer diameter which is slightly less than the, inner diameter of the neck 11, and the section 27 has. an outer diameter whichis slightly less than the inside diameterof the annular formation 46. The resulting clearance between the control head portion 20 and the neck 11 provides a passageway through which pressure in the container can vent to the atmosphere when the control head is depressed as described hereinafter. A shoulder 50 is formed at the junction of the sections 26 and 27 and cooperates with the formation 46 to limit the distance the control head can be depressed.

The locking arrangement includes, in addition to the locking clip 16, a pair of parallel, grooves 51 and 52 formed in the top surface of the upper section 26, and a pair of apertures 54,55 and 56, 57 in the neck 11 aligned with each of the grooves 51. and 52 respectively.

Each of the grooves 51 and 52 respectively have a wide upper portion 58', 59 equal in width to the aperture in the neck 11, and a lower portion60, 61 which isnarrowed by the presthe groove along its inner edge.

The locking clip 16 has a pair of flat parallel arms 64, 65 and a flat connecting base portion 66. When the clip 16 is in place and the container pressurized, the arm 64 is positioned in the portion 61 of the grove 52, and the base portion 66 extends along the outer surface of the neck 11 at the front of the extinguisher. As shown in FIG. 3, the rear ends of the arms 64, 65 are provided with hook portions 67, 68 which extend inwardly along rear faces 70, 71 of the formations 62, 63. The neck 11 is also provided with an upwardly facing aligning slot 72, and the control head 12 is provided with a formation 74 which is received by the slot 72 to align the apertures with the grooves.

In operation, the unit is charged by pouring the liquid or dry powder chemical fire extinguishing agent into the container through the neck 11 before the control head 12 is placed in position. The control head is then slipped into the neck 11 with the formation 74 positioned within the slots 72, and is pushed downwardly until the upper portions 58 and 59 of the grooves 51 and 52 are in horizontal alignment with the apertures 54, 55 and 56, 57 respectively. The clip 16 is then inserted into the apertures from the front of the extinguisher.

The container is then pressurized, either through the discharge passageway 25 or through a separate charging port (not shown As the pressure builds up within the container 10, it acts upon the bottom surface of the control head 12 and moves the control head upwardly against the clip 16. The control head 12 is now in the position shown in the drawing with the O-ring 48 engaging the surface 47 to provide a gas tight seal between the control head and the neck.

The arms 64, 65 of the clip 16 are engaged by the substantial area of the bottom surfaces of the grooves 51 and 52. The pressure loading on the control head is thereby distributed over a sufficient area to reduce the loading per unit unit area to a value which allows the control head to be made of plastic.

The vertical movement of the control head, in response to the pressurizing of the extinguisher, places the formations 62 and 63 in vertical alignment with the clip 16. Therefore, the clip 16 cannot be withdrawn because the hook portions 67 and 68 would engage the rear surfaces 70 and 71 of the formations 62 and 63.

In order to withdraw the clip 16 so that the control head can be removed to refill or otherwise service the extinguisher, the person servicing the extinguisher manually pushes the control head down into the neck to place the groove portions 58 and 59in horizontal alignment with the clip 16.

The downward motion of the control head necessary to align the groove portions 58 and 59 with the clip 16, moves the O-ring 48 out of engagement with the surface 47 to break the pressure seal between the control head and the neck and allow any remaining pressure to vent to the atmosphere before the clip is withdrawn.

If the extinguisher being serviced has not been completely discharged and a substantial pressure remains therein, the service man will know this immediately from the force required to depress the control head. Under this condition, the service man will discharge the unit by operating the valve 14, before disassembling the extinguisher.

From the foregoing description it will be seen that the present invention provides apparatus of the class described having an improved threadless control head locking arrangement which permits extremely low cost construction.

As various changes may be made in the form, construction and arrangement of the parts herein, without departing from the spirit and scope of the invention and without sacrificing any of its advantages, it is to be understood that all matter herein is to be interpreted as illustrative and not in any limiting within said neck for vertical movement between an upper operational position and a lower venting positron, means on said members for providing a seal between saidmembers when said control head member is in said operational position and for breaking said seal when said control head member is in said venting position, said control head member having a cylindrical lower portion within said neck and a narrow upper portion extending upwardly from said lower portion, said lower portion being provided with an upper surface including an elongated surface area extending on each side of said upper portion, said neck being provided with an aperture at each end of each of said elongated areas, and a locking member having a pair of parallel arms each extending over one of said areas and being disposed in said apertures at the ends thereof.

2. Apparatus according to claim 1, wherein said control head member is provided with a formation extending upwardly from at least one of said areas and at least one of said arms is provided with a projection for engaging said formation to prevent withdrawal of said locking member when said control head member is in its operational positon, said formation having a vertical extent such that said locking member can be withdrawn only when said control head member is in its venting position.

3. Apparatus according to claim 1, wherein an upwardly extending formation is provided between each of said surface areas and said upper portion of said control head, and said arms of said locking member are provided with projections at the free ends thereof extending inwardly toward each other so as to be separated by a distance greater than the width of said upper control head portion and less than the distance between the outer edges of said formations whereby said locking member can be withdrawn only when said formations are moved downwardly out of alignment with said locking member, said formations having a vertical extent above said surfaces such that said formations are out of alignment with said locking member only when said control head is in said venting position.

4. Apparatus according to claim 3, wherein said neck member is provided with an alignment slot extending vertically downward from the upper edge thereof and said control head member is provided with an alignment formation to be received by said alignment slot when said control head member is properly positioned with respect to said neck member.

5. Apparatus according to claim 4, wherein said elongated surface areas are the bottom surfaces of a pair of parallel grooves provided in said upper surface of said lower control head portion on opposite sides of said upper portion of said control head.

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