Receptacles – Closures – Key controlled
Reexamination Certificate
1998-02-17
2001-05-01
Shoap, Allan N. (Department: 3727)
Receptacles
Closures
Key controlled
C070S173000, C070S221000, C220S086200, C220S203220, C220S231000, C220S746000
Reexamination Certificate
active
06223923
ABSTRACT:
FIELD OF THE INVENTION
This invention relates generally to the field of gas caps of the sort that attach to the mouths of filler tubes of gas tanks, for example, of automobiles. More particularly, this invention relates to gas caps of the type that are lockable to prevent third party access to the gas tank, and include a mechanism to permit vapour pressure built up in the gas tank to be safely vented.
BACKGROUND OF THE INVENTION
Many of our modern devices make use of internal combustion engines. Typically associated with an internal combustion engine, will be a fuel reservoir such as a gas tank. In many applications, unwanted third party access to the gas tank is to be prevented. Therefore, especially in the automotive field, there have been developed what are generally referred to as lockable gas caps.
A lockable gas cap is a gas cap which includes a plug element, for plugging the filling tube of the gas tank, and, a handle element which may be gripped to remove the plug element from the mouth of the filling tube. Typically, a lock is mounted between the handle and the plug element for selectively locking the two components together. Thus, when the handle is locked to the plug element, the handle and the plug element may be rotated together, and therefore, the plug may be removed from the mouth of the filler tube. Similarly, where the lock is disengaged, the handle will be free to rotate relative to the plug element. Where the plug element for example is threaded into the filler tube, without an operative or drive connection between the handle and the plug element, the plug element cannot be removed from the filler tube. This therefore prevents unwanted third party access to the filler tube and attendant gas tank.
Under vehicular codes, there is a requirement that the gasoline storage tanks of automobiles and the like be made vapour tight to prevent the escape of gas vapours into the atmosphere. Typically, the requirement is that the gas tank be capable of withstanding pressure build up of at least one half an atmosphere above ambient pressure conditions. Such a pressure build up can be hazardous. More particularly, upon removal of a plug element from a pressurized gas tank, there is a risk of a rush of gas vapour and liquid, which can spill onto the person removing the gas cap. Gasoline may then come into contact with clothing and skin, which is less than ideal. Gasoline, being highly flammable, should not be allowed to soak a person's clothes. Also, staining is a problem.
To overcome this problem, some manufacturers have developed pressure release mechanisms associated with their locking gas caps. For example, U.S. Pat. No. 5,520,300 shows a lockable pressure relief fuel cap in which the pressure relief mechanism is associated with the locking mechanism. However, the means for actuating the vent, to release the overpressure in the fuel tank, operates only in response to movement of the lock from the locked position to the unlocked position. In other words, during the act of unlocking, the internal mechanism of this prior gas cap, causes a vent to open, to create a pressure release. This invention therefore includes a complicated series of posts, ramps and biasing elements to effect the translation of rotational movement into vent release movement. This is somewhat complicated and expensive to implement because of the number of parts required.
Other solutions, include a lockable pressure release mechanism for a radiator cap for a vehicle engine such as shown in U.S. Pat. No. 3,945,454. Radiator caps are substantially different from gas caps, and therefore are constructed according to different standards. Most particularly, radiator caps must stand significantly greater pressure build ups than one half of one atmosphere above ambient, which is the design level for gas caps.
U.S. Pat. No. 3,945,454, shows a radiator cap having a locking element which is a combination locking and unlocking device and pressure release device. However, according to this prior patent it is necessary, once the key is inserted to depress the key cylinder in the radiator cap sufficiently to permit a locking pin
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to move a slider into locking engagement. The locking engagement connects the plug element to the handle element. Turning the key in the lock cylinder, without axial movement of the lock cylinder results in the locking pin idly turning and no locking engagement being made. This patent teaches that the lock cylinder must be moved axially a predetermined amount in order to lock the plug element to the handle. A pressure relief valve is located so that the valve is open when the locking element is moved axially enough to lock the plug element and the handle together.
Of course, in a radiator cap environment, where significant pressures are built up behind the cap, requiring a predetermined amount of axial movement of the lock cylinder, in order to open the valve a predetermined amount, is required. In the absence of such a requirement, a user would likely not provide sufficient force to act against the pressure built up within the radiator, to cause a pressure relief prior to removing the cap. Failing to adequately relieve the pressure prior to removing the radiator cap, could result in hot radiator fluid spewing out over the person removing the cap which is both unsafe and undesirable. However, requiring the movement of the locking element to be connected to the movement of the valve for the pressure release, requires extra components, and is complicated and expensive to implement.
Lefevre
U.S. Pat. No. 5,667,093
Issue Date September 16, 1997
Wheat et al.
U.S. Pat. No. 5,000,339
Issue Date March 19, 1991
Fukuta
U.S. Pat. No. 4,579,244
Issue Date April 1, 1996
SUMMARY OF THE INVENTION
What is desired is an inexpensive way to reliably provide pressure relief for a gas tank, while at the same time providing a reliable locking and unlocking mechanism for a lockable gas cap. Most preferably, the pressure relief mechanism and locking mechanism should be simply and elegantly configured, with a minimum of extra parts and requirements on the part of the user. Also, it should provide a safe pressure release reliably, without any extra effort on the part of the user. What is desired is to make the pressure release step essentially invisible to the user. Therefore, there is provided according to the present invention, a lockable gas cap for closing the mouth of a filling tube of a gas tank, the filling tube having internal threads, the gas cap comprising:
a plug element having external threads sized and shaped to engage the internal threads of the filling tubes;
a handle element mounted on said plug element; and
a lock movably housed in said plug element, said lock having a first and a second manner of movement within said plug element, said first manner of movement being between a locked and an unlocked position, and said second manner of movement being between a pressure containing and a pressure release position
wherein said first manner of movement is independent from said second manner of movement.
REFERENCES:
patent: Re. 27303 (1972-03-01), Durso et al.
patent: Re. 27307 (1972-03-01), De Lalio
patent: 1453299 (1923-05-01), Wetzel
patent: 1847117 (1932-03-01), Lantero
patent: 1985787 (1934-12-01), LeBourveau
patent: 2010200 (1935-08-01), Rufener et al.
patent: 2437674 (1948-03-01), Armbruster
patent: 2679946 (1954-06-01), Friend
patent: 2793777 (1957-05-01), Lewis
patent: 2867342 (1959-01-01), Baars et al.
patent: 3682343 (1972-08-01), Landen
patent: 3703245 (1972-11-01), Brewer
patent: 3735887 (1973-05-01), Morris
patent: 3856316 (1974-12-01), Badberg
patent: 3907155 (1975-09-01), Smith et al.
patent: 3915335 (1975-10-01), Shanklin et al.
patent: 3937357 (1976-02-01), Burgess
patent: 3938692 (1976-02-01), Crute
patent: 3945454 (1976-03-01), Kinoshita et al.
patent: 3998078 (1976-12-01), Detwiler
patent: 4000632 (1977-01-01), Summan
patent: 4000633 (1977-01-01), Evans
patent: 4013191 (1977-03-01), Gerdes
patent: 4036399 (1977-07-01), Gerdes
patent: 4049152 (1977-09-01), Treanor
patent: 405
Eloshway Niki M.
Shoap Allan N.
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