Key chain alarm and light

• US 5,475,368 A
• Filed: 07/01/1994
• Issued: 12/12/1995
• Est. Priority Date: 07/01/1994
• Status: Expired due to Fees

• Current Assignee: DAC Technologies of America
• Original Assignee: DAC Technologies of America, Inc. (DAC Technologies Group International Incorporated)
• Inventors: Collins, David A.
• Primary Examiner(s): Peng, John K.
• Assistant Examiner(s): Lee, Benjamin C.
• Application Number:
  US08/269,784
• Time in Patent Office: 529 Days
• Field of Search: 340/573, 340/574, 340/691, 340/693, 340/321, 340/326, 340/384, 340/391.1, 340/388.4, 310/321, 310/323, 310/334, 310/335
• US Class Current: 340/574
• CPC Class Codes: G08B 15/004 using portable personal devices hand-held or body-worn self-defence devices using repellent gases or chemicals F41H9/10

Abstract

A key chain alarm and light is disclosed that overcomes the problems associated with prior art personal alarms. The invention combines the functionality of a key chain, flashlight and an alarm into a unitary assembly. The invention is physically diminutive in size and ergonomically shaped to facilitate its handling. However, it produces an audible alarm significantly louder than other prior art devices. The invention utilizes a unique speaker assembly to produce an extremely loud alarm signal. A piezoelectric transducer provides the vibratory medium. The vibrations produced by the transducer are acoustically focused and harmoniously amplified by an acoustic chamber before passing into a reverberation chamber. The reverberation chamber also increases the amplitude of the sound waves before selectively releasing them to produce the alarm signal. This signal immediately draws attention to the user in emergency situations. The alarm is easily activated by simply moving a switch to activate the alarm. The alarm can also be easily deactivated by reversing the switch. The switch also cooperatively activates the light. A push button on the exterior of the casing of the key chain alarm and light must also be depressed to activate the light.

Claims

1. A key chain alarm and light assembly comprising:

a portable ergonomic casing adapted to be transported by a user, said casing comprising a first half and a second half adapted to be coupled together, said halves having perimeters that are substantial mirror images of one another, said coupled halves defining an interior, an exterior, and a portion adapted to be coupled to a key chain or an eyelet;

a piezoelectric transducer disposed within said casing for acoustically vibrating air and producing loud sounds calling attention to the user;

a resonator for mounting said transducer, said resonator comprising a biconcave plate spaced apart from said transducer and surrounded by a peripheral ring;

an acoustic chamber formed within said resonator between said transducer, said plate, and said ring;

an annular housing within said casing for receiving said resonator, said ring coaxially fitting within said housing;

a reverberation chamber defined within said housing beneath said plate, said reverberation chamber bounded by an annular reflective surface formed in said casing and spaced apart from said plate;

a transmission orifice defined in said plate for connecting said acoustic and reverberation chambers in fluid flow communication;

an outlet orifice defined in said casing adjacent said housing for connecting said reverberation chamber in fluid flow communication with the exterior of said casing, said outlet orifice generally concentric with said transmission orifice and said annular reflective surface, said outlet orifice having a circular periphery;

a reflector disposed within said outlet orifice for reflecting sound within said reverberation chamber;

circuit means for activating said alarm means, said circuit means comprising a circuit board captivated between said casing halves;

light means projecting from said casing for selectively illuminating said key chain or an eyelet; and

,

switch means for selectively activating said circuit means or said light means, said switch means comprising a primary switch slidably captivated between said casing halves within a slot formed on the perimeter of both halves.

2. The key chain alarm and light assembly as described in claim 1 wherein said switch means further comprises a push button switch controlled by said primary switch and operable to activate said light means.

3. The key chain alarm and light assembly as described in claim 2 wherein the ratio of the transducer diameter to the transmission orifice diameter to the outlet orifice diameter is 5 to 1 to 3.

4. The key chain alarm and light assembly as described in claim 3 wherein said transducer diameter is between one quarter of an inch and three inches.

5. A key chain alarm and light assembly comprising:

a portable ergonomic casing adapted to be transported by a user, said casing comprising an interior, an exterior, and a portion adapted to be coupled to a key chain;

a piezoelectric transducer disposed within said casing for acoustically vibrating air and producing audible sounds calling attention to the user;

a resonator for mounting said transducer, said resonator comprising a biconcave plate spaced apart from said transducer and surrounded by a peripheral ring;

an acoustic chamber formed within said resonator between said transducer, said plate, and said ring;

an annular housing within said casing for receiving said resonator, said ring coaxially fitting within said housing;

a reverberation chamber defined within said housing beneath said plate, said reverberation chamber bounded by an annular reflective surface formed in said casing and spaced apart from said plate;

a transmission orifice defined in said biconcave plate for connecting said acoustic and reverberation chambers in fluid flow communication;

an outlet annulus defined in said casing adjacent said housing for connecting said reverberation chamber in fluid flow communication with the exterior of said casing, said outlet annulus generally concentric with said transmission orifice and said annular reflective surface, said outlet annulus having a circular periphery;

a reflector surrounded by said outlet annulus for reflecting sound within said reverberation chamber, said reflector having a concave inner surface facing said transmission orifice and a convex outer surface projecting outwardly from said casing for distributing sound emanating from said outlet annulus;

circuit means for activating said alarm means;

light means projecting from said casing for selectively illuminating said key chain; and

,

switch means for selectively activating said circuit means or said light means.

6. The key chain alarm and light assembly of claim 5 wherein said outlet annulus is subdivided into a plurality of radially spaced apart, arcuate radiation slots.

7. A battery powered personal key chain alarm and light adapted to selectively function as a light or an alarm, said alarm and light comprising:

an ergonomic casing that facilitates handling of the alarm, said casing comprising a first and a second halves, the perimeters of said halves being substantially mirror images with a slot formed between said halves;

a switch partially slidably captivate within said slot and a complementary push button partially housed between said first half and a circuit board, said push button penetrating an orifice formed in said first half, said switch and said push button adapted to cooperatively activate a light to illuminate objects, said light physically mounted on said circuit board housed inside said casing;

an annular collar formed between said circuit board and said second half;

a speaker assembly partially housed within said collar and captivated by said collar, said speaker assembly adapted to produce an audible alarm signal and comprising;

a transducer for acoustically vibrating to produce sound waves;

a spaced apart biconcave, circular plate adjacent said transducer and forming an acoustic chamber therebetween, said acoustic chamber resonating said sound waves;

a circular transmission orifice penetrating said plate at the center thereof and permitting the transmission of said sound waves from said acoustic chamber;

a concave reflector integrally attached to one of said halves and concentrically spaced apart from said transmission orifice, said reflector preventing the immediate escape of at least some of said sound waves; and

,

a reverberation chamber between said plate and said reflector, said reverberation chamber harmoniously amplifying said sound waves;

said circuit board adapted to selectively activate said speaker assembly or said light; and

,

at least one battery housed within said casing and adapted to provide electrical power to activate said circuit board.