US3302664A

US3302664A - Safety cap assembly for pressurized founts of gasoline burning devices

Info

Publication number: US3302664A
Application number: US358016A
Authority: US
Inventors: William H Plamann
Original assignee: Coleman Co Inc
Current assignee: Coleman Co Inc
Priority date: 1964-04-07
Filing date: 1964-04-07
Publication date: 1967-02-07
Anticipated expiration: 1984-02-07

Description

Feb. 7, 1967 w. H. PLAMANN 3,302,664

SAFETY CAP ASSEMBLY FOR PRESSURIZED FOUNTS OF GASOLINE BURNING ICES Filed April 7, 1

W a W United States Patent 3,302,664 SAFETY CAP ASSEMBLY FOR PRESSURIZED FOUNTS 0F GASOLINE BURNING DEVICES William H. Plamann, Wichita, Kans., assignor to The Coleman Company, Inc., Wichita, Kans., a corporation of Kansas Filed Apr. 7, 1964, Ser. No. 358,016 3 Claims. (Cl. 138-89) This invention relates to a safety cap assembly for pressurized founts of gasoline burning devices. The safety cap assembly has particular utility for use with the founts or reservoir tanks of portable gasoline burning devices, such as gasoline lanterns, gasoline stoves, etc.

Such gasoline burning devices are provided with gasoline storage tanks or founts, which are an integral part of the complete lantern or stove, and which therefore are located in close proximity to the gasoline burning element, such as the stove burner or the illumination burner. It is necessary, of course, to provide a filler inlet in the top of upper portions of the founts, which inlet is equipped with a removable cap to permit the founts to be refilled with gasoline as required. Since the operation of the devices requires that the founts be pressurized, a hand pump being provided for creating the required pressure within the founts, the removal of the closure caps may involve a sudden release of pressure as the cap is unscrewed. This pressure release may cause the gasoline in the fount to froth or foam, and either liquid gasoline or gasoline froth may blow out and be ejected with the outward movement of air in the release of the fount pressure.

It is, therefore, a general object of the present invention to provide a safety cap assembly for pressurized founts of gasoline burning devices which overcomes the problems described above, while at the same time being simple and economical to manufacture and which performs satisfactorily under repeated use. More specifically, it is an object to provide a safety cap assembly of a type described which positively directs the released air and gasoline away from the burner element of the stove or lantern, and which therefore provides for a safe opening of the filler inlet even if the burner element is at a relatively high temperature or is still ignited. Other objects and advantages will be indicated in the following detailed specification.

This invention is shown in an illustrative embodiment in the accompanying drawing, wherein FIGURE 1 is an elevational view of a. gasoline lantern equipped with a pressurizedfount and a filler inlet of a kind with which the present invention is particularly applicable; 7

FIG. 2 is an enlarged fragmentary side elevational view of the fount of the lantern in FIG. 1, showing the safety cap assembly as it would appear in place during the normal operation of the lantern;

FIG. 3 is an enlarged detail view, partly in section, of the safety cap assembly;

FIG. 4 is a transverse sectional view of the safety cap assembly taken on line 44 of FIG. 3;

FIG. 5 is a bottom view of the cap and gasket members of the assembly; and

FIG. 6 is an enlarged fragmentary sectional view illustrating the method of functioning of the pressure release means of this invention.

In FIG. 1 of the drawings, there is shown a gasoline lantern 10 having a gasoline tank or fount 11 which is equipped with the usual hand pump 12 for creating pressure within the fount. Fount 11 is provided with a safety cap assembly constructed in accordance with the present invention, the assembly being designated generally by the 3,382,664 Patented Feb. 7, 1967 ice number 13. It will be understood, however, that the safety cap assembly of this invention is adapted for use in conjunction with other gasoline burning devices having pressurized founts, including particularly gasoline-burning camp stoves.

As shown more clearly in FIGS. 2 and 3, the safety cap assembly includes a filler bushing or sleeve 14 having a lower portion 15 adapted for attachment to the fount 11, and an externally threaded upper portion 16. In the illustration given, lower end 15 of the bushing is provided with an annular shoulder 16 which facilitates the uniting of the bushing to the fount through a ring of copper braze 17. It will be understood that other methods of attachment can be employed, such as Welding.

A closure cap 18 provided with internal threads 19 is received on the threaded upper end 16 of the bushing 14. The bushing threads 20 are in threaded engagement with the cap threads 19, as shown more clearly in FIGS. 3 and 6.

The cap assembly is provided with gasket means mounted within the cap 13 for establishing sealing engagement with the upper end of the bushing. In the illustration given, there is provided a gasket ring 21 which is held ina recess of a gasket carrier 22. To permit cap 13 to be rotated independently of gasket 21 and carrier 22, the carrier is supported by means of a retainer screw 23. This arrangement tends to minimize frictional wear on the gasket during the final stages of tightening the cap or the initial stages of removing the cap. The bottom face of the gasket 21 can thereby be engaged and disengaged with the outer end 24 of the bushing without a relative scrubbing action between the parts. This constrnction in itself is not new, and in fact is well known in the art, and it is not believed it will be necessary to further describe it herein.

As already indicated, this invention is particularly concerned with a means of achieving a safe release of the fount pressure when the cap 13 is unscrewed. Consequently, in accordance with the present invention, one of the engaging threaded portions of the bushing 14 and the cap 18 is provided with a plurality of circumferentially spaced, axially-aligned channels extending across the zone of threaded engagement between these parts. For achieving the results of the present invention, these channels are designed to provide open paths of communication between the exterior atmosphere at the bottom of the cap and the interior of the cap adjacent the level of sealing engagement between the bushing end 24 and the gasket 21. As shown in'FIGS. 3 and 6, the bushing end 24 and the gasket 21 seal at a level outwardly of the zone of threaded engagement between the bushing threads 20 and the cap threads 19.

Bushing threads 26 may advantageously be provided in a band area which is adjacent the outer end 24 of the bushing but spaced inwardly therefrom. As shown in FIGS. 3 and 6, this construction provides an annuular space 25 immediately adjoining the lower face of gasket 21 and the upper end 24 of the bushing. As indicated in FIG. 6, a separation of the gasket 21 from the bushing end 24 brings the annular space 25 into communication with the interior of the fount through the passage provided by the bushing 16. Thus, the pressurized air together with liquid gasoline or gasoline froth will first enter the annular space 25 after it passes between gasket 21 and bushing end 24 as these parts are separated in the unscrewing of the cap. Since space 21 extends entirely around the inside of the cap, the fluid under pressure can distribute itself around the circumference of the cap within the passage 25. The means for safely venting the pressurized fluid from the annular passage 25 will now be described.

In the illustration given, the inside of cap 18 is provided with a plurality of channels 26. The channels are axially aligned and extend upwardly from the lower end of cap 18 to a level adjacent the level of sealing engagement between the gasket 21 and the bushing end 24. As shown more clearly in FIGS. 3 and 6, the inner ends of the channels 26 communicate directly with the annular pressure relief space 25. Preferably, more than one of the channels 26 are provided in communication with the annular space 25, and the channels 26 may be circumferentially spaced around the inside of the cap. In the illustration given, four of the channels 26 are provided, and are equally spaced around the interior of the cap, as shown more clearly in FIGS. 4 and 5. In order that the pressure relief passages provided by the channels 26 are in open communication with the annular space 25 and the exterior atmosphere, the channels have a greater depth than the threads 19 across which the channels extend. More specifically, the bottoms of the channels 26 are outwardly of the root depth of the threads 19, as shown particularly in FIGURES 3 and 6.

In the manufacture of the caps 18, the channels 26 may be advantageously formed by a broaching operation prior to the cutting of the threads 19. Formation of the channels after threading might damage the threads. If desired, the channels 26 may extend upwardly further than shown in the drawings, although this would usually be unnecessary where the annular passage 25 is employed adjacent the inner ends of the channels.

There is an advantage in forming the pressure relief channels in the cap, especially where the cap is formed of a softer metal, such as brass, while the bushing is formed on a harder metal, such as steel. Where the member providing the channels is formed of a softer metal than the other member, there is much less tendency for the channels to act as thread chasers with resulting damage to the threads of the other member. It will be understood that the cap 18 may be formed of other relatively soft metals, such as aluminum or copper, While providing the same advantages. Alternatively, the bushing 14 may be formed of a relatively soft metal, such as brass, aluminum, copper, etc., while the cap 18 is formed of a relatively harder metal, such as steel. Where the bushing is formed of a softer metal than the cap, the broached channels should be formed in the bushing while the threads in the cap will be uninterrupted.

To facilitate gripping of the cap 18 with the fingers, it can be provided around its outside with a knurled surface 27.

Operation The operation of the safety cap assembly of this invention is illustrated particularly in FIGS. 3 and 6. In FIG- URE 3, the cap assembly is shown in closed position with the gasket 21 in sealing engagement with the upper end 24 of the bushing. In this condition, the gasoline in fount 11 will normally be under pressure as produced by the pump 12. As cap 18 is unscrewed by manually gripping the knurled surface 27, the gasket 21 will separate from the bushing end 24 with a breaking of the sealing engagement therebetween. The pressurized air from within the fount, together with any entrained liquid gasoline or gasoline froth, with then flow into the annular space 20, as indicated in FIG. 6, and from there outwardly through the channels 26. Since these channels are directed downwardly toward the upper surface of the fount 11, the entrained gasoline or gasoline foam is safely discharged, and is kept away from and out of contact with the burner element of the heating device. As will be noted, the direction of discharge is not dependent on the position of the cap 18 as it is being unscrewed. After the pressure has thus been safely released, the cap 18 can then be unscrewed the rest of the way and removed from the bushing 14.

While this invention has been described in the foregoing specification in relation to a specific embodiment thereof, it will be apparent to those skilled in the art that hte invention is susceptible to other embodiments without departing from the basic principles of the invention, and that many of the details described herein can be varied considerably while still achieving the objects of this invention.

I claim:

1. In a safety cap assembly, including a filler bushing having a lower portion for attachment to a pressurized fount of a gasoline burning device and an externally threaded upper portion, an internally threaded closure cap received on said bushing upper end portion in threaded engagement therewith, and gasket means mounted within said cap for establishing sealing engagement with the upper end of said bushing at a level outwardly of the zone of threaded engagement between said cap and bushing, the means for achieving a safe release of the fount pressure when said cap is unscrewed characterized by said cap being provided with a plurality of circumferentially spaced, axially aligned channels extending inwardly from the lower end thereof to the level of said sealing engagement, said cap being formed of a substantially softer metal than said bushing, said channels having a greater depth than the root depth of the threads in said cap, and providing open paths of communication for both liquid and vapor between the exterior atmosphere at the bottom of said cap and said level of sealing engagement adjacent said gasket.

2. The safety cap assembly of claim 1 wherein said cap is formed of brass and said bushing is formed of steel.

3. The safety cap assembly of claim 1 characterized further in that the threads on said bushing terminate at a spaced distance from the upper end thereof, and an annular space is provided around the outer end portion of said gasket, the upper portions of said channels communicating with said annular space.

References Cited by the Examiner UNITED STATES PATENTS 1,022,211 4/1912 Thomas 22()-29 1,228,285 5/1917 Bieker 220--29 1,649,587 11/1927 Halaby 220--44 2,202,185 5/ 1940 Broecker. 2,990,079 6/1961 Garvey 215-56 THERON E. CONDON, Primary Examiner.

JAMES R. GARRETT, Examiner.