US3530941A

US3530941A - Fire extinguisher with a pin connected control head

Info

Publication number: US3530941A
Application number: US760584A
Authority: US
Inventors: Arne Hansen; Lester V Hebenstreit
Original assignee: Walter Kidde and Co Inc
Current assignee: Kidde Inc
Priority date: 1968-09-18
Filing date: 1968-09-18
Publication date: 1970-09-29
Anticipated expiration: 1987-09-29

Description

United States Patent [72] Inventors Arne 8r Hansen,

New City, New York; Lester V. Ilebenstreit, Bloomfield, New J y Appl. No. 760,584

Filed Sept. 18, 1968 Patented Sept. 29, 1970 Assignee Walter Kidde & Company, Inc.

Belleville, New Jersey a corporation of Delaware FIRE EXTINGUISIIER WITH A PIN CONNECTED CONTROL HEAD References Cited Primary Examiner- Lloyd L. King 7 Assistant ExaminerThomas C. Culp, Jr. 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 congcmmsanrawing Figs tainer by a U-shaped pin extending through vertically elon- U.S. 169/31, gated slots in the neck and control head. The pin is capable of l69/30 being withdrawn, to remove the control head only when the I t. Cl A62c 13/00 control head is depressed into the neck sufficiently to render Field of Search 169/30, 31; the sealing arrangement between the neck and control head 222/ I45, 545; 220/46 ineffective and allow pressure within the container to vent.

38 33 0 2 l I I 4 I l l 2 1 40 i 1 7 2 2 1 I i 1 I i i s 15 FIRE EXTINGUISI-IER- WITH A PIN CONNECTED CONTROL HEAD BACKGROUND OF THE INVENTION l. Field of the Invention The present invention relates to apparatus for confining and dispensing fluid medium under pressure, such as portable fire extinguishers, insecticide spraying apparatus 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 In apparatus of the class described, it has been common practice to utilize a metal control head which is threaded onto or into the neck of the container.

While this type of construction has proven to be completely satisfactory from a functional point of view, the cost of the metallic materials used in the control heads and the cost of machining these materials are factors which have severely limited attempts at price reduction in this type of apparatus.

SUMMARY Accordingly, an object of the present invention is to provide apparatus of the class described having an improved control head locking arrangement enabling low cost construction.

Another object is to provide such improved apparatus which can be serviced rapidly without tools and without hazard.

Other and further objects of the invention will be obvious upon an understanding of the illustrative embodiment about to bedescribed, or will be indicated in the appended claims, and various advantages not referred-to herein will occur to one skilled in the art upon employment of the invention in practice. I

In accordance with the present invention, the foregoing objects are generally accomplished'by providing in fluid medium dispensing apparatus the combination of a container for storing fluid medium under pressure having an opening, a tubular neck member at the opening of the container, a removable control head member slidably mounted in the neck member and having an outer operational position and an inner venting position, a sealing arrangement for providing a seal betweenthe members only when the control head member is in its operational position, and a disengageable locking arrangement for preventing outward movement of the control head past the operational position, the locking arrangement being disengageable only when the control headis in its venting position.

BRIEF DESCRIPTION OF THE 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 longitudinal sectional view partly in elevation 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 2-2 on FIG. 1.

FIG. 3 is a sectional view taken along the line 3-3 on FIG. 2.

DESCRIPTION OF THE PREFERRED EMBODIMENT 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 arrangement 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 I0, and a locking arrangement including a U-shaped locking pin 16.

'The extinguisher shown herein is of the type adapted to be partially filled with a fluid medium, such as water or dry chemical powder, and'then pressurized with a gas for the purpose of forcing the 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 extending above the neck, an axial bore 24 in the portion 20 for receiving the syphon tube, and a discharge passageway 25 in the portion 23 connecting with the bore 24.

The discharge passageway 25 includes an axial bore 26 in communication with the bore 24 and a lateral bore 27 intersecting the bore 26. A bore 29 of smaller diameter than the bore 26 extends coaxiallywith the bore '26 from the intersection of the bore 27 upwardly through the upper surface of the control head.

The valve 14 includes a valve seat 30 formed at the junction of the bore 26 with the bore 24, and a valve member 31 having a head portion 32 positioned in the bore 24 and a stem portion 34 extending upwardly therefrom through the

bores

26 and 29 past the upper surface of the control head. An O-ring 35 is mounted on the stem 34 to provide a seal between the stem and the bore 29, a collar 36 is mounted near the upper end of the stem above the control head, and a spring 37 is positioned between the upper surface of the control head and the collar 36 to hold the valve closed.

A metal handle 38 is riveted or otherwise rigidly secured to the control head portion 21, and a valve operatinglever 39 is pivotally mounted at 33 on the control head and extends over the handle 38 so that the valveis operated when the lever and, the handle are grasped in one hand and squeezed. I

The sealing arrangement 13 includes an annular formation 40 at the bottom of the neck 11 providing a cylindrical surface 41, and an O-ring seal 42 which is mounted in an annular recess 48 formed in the section 22 of the control head to seal against the surface 41. V

The section 21 of the lower control head portion 20 has an outside diameter which is slightly less than the inner diameter of the neck 11 and the section 22 has an outside diameter which is slightly less than the inside diameter of the formation

gated slots

44 and 45 extending through the control head portion 20, a pair of vertically

elongated slots

46 and 47 in the neck 11 aligned with the slot44, and a pair of vertically

elongated slots

49 and 50 in the neck 11 aligned with the slot 45.

The slots have upwardly and downwardly facing end surfaces for engaging the locking pin.

The locking pin 16 is provided with a pair of

parallel arms

51 and 52 and a connecting base section 54. The arm 51 extends through the

slots

44, 46 and 47, and the arm 52 extends through the

slots

45, 49 and 50. In this manner, the locking pin extends perpendicularly with respect to the longitudinal axis of the neck. The

arms

51 and 52 are of sufficient length to pass through the control head and the neck and extend outwardly beyond. As shownin FIG. 3, the arms 51 and '52 are bent where they emerge from the neck 11 to form obstructing

sections

55 and 56 which prevent withdrawal of the pin'l6 when the control head 12 is in the position illustrated in thedrawing.

The slots in the control head 12 and the slots in the neck 11 are vertically oriented with relationship to the sealing arrangement 13 so that the slots are in perfect alignment to allow. the

withdrawing of the pin only when the control head is moved downwardly sufficiently to place the O-ring 42 below the surface 41.

In operation, the apparatus 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 ll and the pin 16 is inserted. The container is pressurized either through the discharge passageway or through a separate charging port (not shown). As pressure builds up within the container 10, it acts upon the bottom surface of the control head 12 and moves the control head 12 upwardly. The bottom surfaces of the

slots

44 and 45 in the control head engage the

arms

51 and 52 of the pin 16 and the pin is lifted until the

arms

51 and 52 engage the upper surfaces of the

slots

46, 47, 49, 50 in the neck 11. The control head 12 is now in the position shown in the drawing with the O-ring 43 engaging the surface 41 to provide a gas tight seal between the control head and the neck.

The pin 16 which locks the control head to the neck is engaged by the substantial area of the lower surfaces of the

grooves

44 and 45. The pressure loading on control head is thereby distributed over a sufficient area to reduce the loading per unit area to a value which allows the control head to be made of plastic.

When the extinguisher is pressurized, the pressure acting on the control head squeezes the pin 16 between the control head and the neck, and the bent end 55 of the pin arm 51 forms an obstruction which engages the neck 11 to positively prevent the pin from being withdrawn while there is any substantial pressure within the container. The end 56 is bent in the opposite direction to provide an obstruction should the pin 16 be inverted.

In order to withdraw the pin 16 so that the control head can be removed, to refill or otherwise service the extinguisher, the control head must be pushed by hand down into the neck to place the control head slots and the neck slots in vertical alignment.

The downward motion of the control head necessary to align the slots, moves the O-ring 42 out of engagement with the surface 41 and breaks the pressure seal between the control head and the neck to allow any pressure remaining in the container to vent to the atmosphere before the pin is withdrawn.

After the

slots

44 and 45 are aligned with the

slots

46, 47 and 49, 50 respectively, the pin is twisted slightly to place the arm 51 at the bottom of the slot 44 and the am 52 at the top of the slot 45 and is pulled laterally out of the slots. The control head is now free and can be lifted out of the neck 11.

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

From the foregoing description, it will be seen that the present invention provides apparatus of the class described having an improved control head locking arrangement which enables low cost construction and allows the apparatus to be serviced without hazard.

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 sense.

We claim:

1. ln fluid medium dispensing apparatus, the combination of a container for storing fluid medium under pressure having an opening, a tubular neck at said opening, a removable control head slidably mounted within said neck and having an operational position and a venting position inwardly of said operational position, means on said neck and said control head for providing a seal therebetween when said control head is in said operational posltlon and for breaking the seal when said control head is in said venting position, and disengageable locking means for limiting outward movement of said control head to said operational position, said locking means being disengageable only upon inward movement of said control head to said venting position.

2. Apparatus according to claim 1 wherein said locking means includes a locking member extending perpendicularly to the longitudinal axis of said neck.

3. Apparatus according to claim 2, wherein said locking means includes an inwardly facing surface on said neck and an outwardly facing surface on said control head, said locking member removably engaging said surfaces to limit outward movement of said control head with respect to said neck.

4. Apparatus according to claim 3, wherein said locking member is slidably positioned between said inwardly and outwardly facing surfaces.

5. Apparatus according to claim 4, wherein said locking means includes at least one obstructing formation for preventing removal of said locking member when said control head is in a position other than said venting position.

6. Apparatus according to claim 5 wherein said locking member is a U-shaped pin having parallel arms and said neck member is provided with openings for receiving said arms of said pin, said parallel arms of said pin being separated by a distance less than the width of said control head.

7. Apparatus according to claim 6 wherein said control head is provided with slots for receiving said arms of said pin, said slots in said control head being elongated to allow inward movement of said control head to said venting position.

8. Apparatus according to claim 7 wherein said obstructing formation is provided on the end of at least one of said arms and extends outwardly in the plane of said slots and said openings in said neck are elongated to allow passage of said formation when said control head is in said venting position.

9. Apparatus according to claim 8 wherein at least one of said arms is provided with an obstructing formation extending inwardly in the plane of said slots to allow said pin to be inverted.