Illumination – With implement or hand held holder therefor – Firearm
Reexamination Certificate
2000-05-31
2001-11-27
Cariaso, Alan (Department: 2875)
Illumination
With implement or hand held holder therefor
Firearm
C362S369000, C362S208000
Reexamination Certificate
active
06322231
ABSTRACT:
FIELD OF INVENTION
The invention is generally related to light emitting devices and is more specifically directed to flashlights having improved vibration resistance.
BACKGROUND OF INVENTION
Law enforcement and military personnel commonly use flashlights and lasers. In use, they may be exposed to harsh operating conditions, including subjection to a great deal of vibration. For example, swat teams, military units, and Special Forces often use lights in the form of flashlights, scopes, laser guidance systems, and other light sources (collectively referred to herein as “flashlights”) attached to firearms such as high powered automatics, rifles, and sub-machine guns. Weaponry with attached light sources are often used during hostage situations, terrorist suppression, and combat to improve visibility typically found in dark, foggy, smoky, or other low visibility settings. It is desirable for these light sources to provide an uninterrupted source of light when subjected to vibration. For instance, a light attached to a firearm experiences immense vibration during firing which may cause the light to flicker. In the case of automatic weapons, the vibrations are extremely intense. In these environments, an uninterrupted source of light is desirable.
Flashlights producing an uninterrupted source of light arc also desirable in other settings having similar harsh operating conditions, including subjection to vibration. In settings such as mining, construction, and manufacturing there may be a need for an uninterrupted and targeted light source. For instance, a reciprocating saw may be used to cut construction materials in poorly lit areas. Some prefer to have a light source illuminating the cutting surface, thereby making the cutting surface easier to see. A flashlight attached to the reciprocating saw will undergo vibration possibly causing the attached light source to flicker, leading to increased chance of operator error and bodily injury. Other applications, including vehicles such as cars, trucks, and motorbikes may have a need for an uninterrupted light source to improve visibility. Consequently, it is desirable for any flashlight attached to or near equipment that is subjected to such harsh operating conditions to provide an uninterrupted source of light and resist the detrimental effects of vibration.
Generally, lights attached to firearms typically include a housing that is formed of a body section and a head section. The head section typically houses a lens, a reflector, and a lamp assembly. These may be secured in the head section by a lens ring that is threadingly engaged with the head section. The body section typically houses a power source such as batteries for energizing the lamp. A switch assembly to control the operation of the lamp is also provided either on the light or on the firearm.
Currently, flashlight designs have certain disadvantages when the light undergoes heavy vibration, which is experienced by the light when attached to a firearm and in other settings where vibration is experienced. The electrical circuit in a flashlight typically includes several points of electrical contact between various components of the flashlight. The integrity of the circuit is dependent on the mating of each point of contact. For example, under heavy vibration the electrical contacts may be momentarily lost thus causing the light to flicker. Even worse, extreme vibration may result in the breakage of a light bulb and an interruption in light. A flickering light, or interrupted source of light, is undesirable and can impair efforts of law enforcement personnel and possibly make the difference between a successful operation and an unsuccessful one.
Thus, there is a need to provide a light source having improved operation when exposed to vibration.
SUMMARY
The present invention overcomes the drawbacks of prior flashlights and the electrical circuits used therein by providing a flashlight with an improved electrical circuit having a point of electrical contact between a lamp assembly and the head section as part of the electrical circuit. Prior flashlights have included a point of electrical contact between a lamp assembly and the head section as part of the electrical circuit. An example is shown in detail in a commonly owned U.S. patent application Ser. No. 08/738,858 incorporated by reference herein, where an electrical contact exists between the lamp assembly and the head section of the flashlight. A lens ring is used to hold the lamp assembly in close contact to the head section to provide a point of electrical contact. This point of contact, as well as other points of contact, is prone to electrical interruption during vibration and may result in undesirable flicker. The present invention includes the use of an electrically conducting contact spring to establish a continuous electrical contact point between the lamp assembly and the head section.
The contact springi, maintains an electrical connection between the head section and the lamp assembly even when the flashlight is subjected to vibration. The head section preferably includes an electrically conducting annular channel that may be found in an extension of the head section. The contact spring is preferably placed in the electrically conducting annular channel. In operation, the use of the contact spring maintains an uninterrupted electrical contact point between the head section and the lamp assembly within the electric circuit and eliminates or reduces the undesirable flicker.
Furthermore, the contact spring absorbs vibration and protects the lamp assembly from vibration that would otherwise be transferred from the head section to the lamp assembly. Thus, the contact spring prevents damage to the lamp assembly, which can lead to a reduced lamp life, a broken lamp, a cracked lens, or a pennanently disabled circuit.
Additionally, an embodiment of the present invention eliminates a contact point within the power source by effectively joining two voltage sources commonly used to power the circuit. The power source, typically two voltage sources in series, are assembled in an embodiment such that only one positive and one negative voltage output contact point are necessary to provide power to the circuit, thereby reducing flicker. By eliminating this contact point, a point of potential electrical interruption, further reduction in flicker is provided.
REFERENCES:
patent: 4313272 (1982-02-01), Matthews
patent: 4740876 (1988-04-01), Roller
patent: 4856218 (1989-08-01), Reyolds, Jr.
patent: 5601359 (1997-02-01), Sharrah
Parsons Kevin L.
Reeves W. Clay
Armament Systems & Procedures, Inc.
Cariaso Alan
Conte Robert F. I.
Lee Mann Smith McWilliams Sweeney & Ohlson
Sawhaney Hargobind S.
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