Self actuating wallet alarm

Abstract

A wallet or the like having incorporated therewith an electronic circuit capable of emitting an audible alarm when the same is removed from an owner's purse or pocket.

Description

BACKGROUND OF THE INVENTION

This invention relates to a wallet, purse, or any other type of case in which persons usually carry valuables as they engage in their daily tasks in or about the public.

It is well recognized that pick-pockets are adept at taking one's wallet from a pocket or purse without causing the slightest disturbance of their victim.

The instant invention is directed to this problem by incorporating an alarm system in a wallet, billfold or the like such that when the same is removed from a pocket or purse a noticable signal will be produced to immediately bring to the owner's attention the fact that his valuable belongings are being removed from his person.

A general object of the invention is to provide a case having a self-actuating alarm system.

A further object of the invention is to provide a wallet or the like having an alarm system responsive to removal from an enclosure.

A still further object of the invention is to provide a wallet or the like having an audible alarm system which will actuate in response to variations of electromagnetic radiation.

A more specific object of the invention is that said alarm system be self-activated in response to exposure electromagnetic radiation within a particular range of wave-length.

A still further object of the invention is provide that the alarm system self-activate when exposed to increases in the levels of electromagnetic radiation.

A specific object of the invention is to provide that the alarm system self-activate when exposed to electromagnetic radiation within the light range.

A further specific object of the invention is that the alarm system comprise a solid state electronic oscillation circuit operable to produce an audible alarm.

The foregoing and other advantages and features of the invention will be apparent from the following more particular description of the preferred embodiment of the invention as illustrated in the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a view of the invention being removed from an enclosure;

FIG. 2 is a perspective view of the invention with parts cut away;

FIG. 3 is an elevational view in section taken substantially at line 3--3 of FIG. 2; and

FIG. 4 is a schematic electrical diagram of the alarm circuit.

DESCRIPTION OF THE PREFERRED EMBODIMENT

Turning attention to FIG. 1, the invention generally designated 10 is being shown removed from an enclosure 11.

Describing the invention in detail and having particular reference to FIGS. 2 and 3, the invention 10 comprises a case 12 and an alarm system 13. As illustrated in FIG. 2 the case 12 is shown as a wallet, billfold or the like comprising a main portion generally designated 15 and a pouch 16.

The pouch 16 comprises an outer wall 17 and a flap 18. The wall 17 is folded about to define a space 20 and is secured to the main portion 15 by way of stitching (not shown) or any other method commonly known in the construction of such cases. It can be seen in FIG. 2 that the outer wall 17 forms an enclosure having an opening 21 at one end thereof through which the alarm system 13 can be inserted into the pouch. The flap 18 folds over the opening 21 to securely retain the alarm system 13 within the space 20. The flap 18 is releasably connected to the wall 17 by a snap 23. The wall 17 also has an aperture 24 which will register with certain portions of the alarm system 13 as hereinafter described.

As can be seen in FIG. 3 the alarm system comprises a circuit board 26 on to which a photo-electric cell 27 and a speaker 28 are mounted. Covering the speaker 28 is a screen or mesh 29. Surrounding and secured to the photo-electric cell 27 is an opaque member 30. It can be seen that the opaque member 30 and the screen 29 are of such dimensions that they entirely fill the aperture 24 in the wall 17 of the pouch 16. It can also be appreciated that the dimensions of the circuit board 26 and the position of the photo-electric cell 27 and speaker 28 together with their associated opaque member 30 and screen 29 are so arranged such that when the alarm system 32 is inserted into the pouch 16 that the opaque member 30 and screen 29 will fully register with the aperture 24.

FIG. 4 illustrates an electronic circuit 35 of the alarm system 13. The circuit 35 has a conductor 36 which connects the positive terminal of a battery 37 to the collector terminal of an n-p-n transistor designated 38. The photo-electric cell 27 is serially connected between the conductor 36 and the base terminal of the transistor 38. A conductor 40 connects the emitter terminal of transistor 38 to the emitter terminal of a p-n-p transistor 41. The base terminal of the transistor 41 is connected to the collector terminal of a transistor 42. It can be seen that transistors 41 and 42 form a quasi-complimentary circuit providing a high output at relatively low cost without the need of well matching the output device to the circuit, the output device being the speaker 28. The collector circuit of transistor 41 is connected by means of conductor 43 to one terminal of the speaker 28. The other terminal of the speaker 28 is connected to the negative terminal of battery 37 by means of conductor 48. The emitter terminal of transistor 42 is also connected to the conductor 48. A resistor 49 is connected between conductor 40 and the base terminal of transistor 42; also connected to the base terminal of transistor 42 is one terminal of a capacitor 50. The other terminal of the capacitor is connected to resistor 51 which in turn is connected to conductor 43. It also can be appreciated that a switch (not shown) could be inserted in either conductor 36 or 48 in such a manner to selectively interrupt leakage current through the circuit 35 when it is contemplated that the alarm system would not be used for extended periods of time.

The operation of the invention is such that when it is placed in an enclosure such as a purse or a pocket the photo-electric cell 27 is shielded from light striking it. However, when it is removed from such enclosure any light striking the cell will cause the resistivity of that cell to decrease. When this occurs the transistor 38 is biased such that the decrease in resistivity of the photo cell 27 causes the transistor 38 to conduct. When this occurs the capacitor 50 is charged through resistor 49 and 51. When the charge on the capacitor 50 reaches a predetermined level the transistor 42 turns on which in turn switches on transistor 41, whereby a relatively low resistance circuit becomes coupled between the positive terminal of the battery 37 and the speaker 28 which as hereinbefore described is also connected to the negative terminal of battery 37. At this time a surge of current will flow through the speaker 28. However, when the transistor 41 conducts it can be seen that effectively a short circuit is placed across that portion of the circuit containing resistor 49 capacitor 50 and resistor 51. Whereby the capacitor 50 is rapidly discharged causing the voltage level at the base terminal of transistor 42 to decrease to the point where it ceases to conduct thereby shutting off transistor 41. Capacitor 50 then recharges again and the entire process is repeated. The circuit parameters are selected such that the current will oscillate in the circuit at a frequency between 2,000 to 4,000 Hertz. The current surge at this frequency through the speaker 28 will produce a loud audible sound thereby instantly warning a person that his wallet, billfold or alike has been removed from the enclosure which he placed it.

It is also contemplated that the photo-electric cell 27 may have characteristics which make it operative within selected and limited wave-length ranges; which may not only be between those wave-lengths associated with visible light but also those wave-lengths in the range of body heat emitted from a person, such that the alarm system would actuate upon being removed from the person.

It will be appreciated that the embodiment of the invention has been chosen for the purposes of illustration and description herein is that preferred based upon requirements for achieving the objects of the invention and developing the utility thereof in a most desirable manner. It will be understood, that the particular structure and functional aspect emphasized herein are not intended exclude but rather to suggest other such modifications and adaptations as fall within spirit and scope of the invention as hereinbefore described.

Claims

What is claimed is:

1. A wallet alarm device comprising:

an alarm system including alarm means operative to produce an alarm signal;

a case having a portion thereof for retaining said alarm means; and

said alarm system including receiving means responsive to sense pre-selected variations of electromagnetic radiation and effective to actuate said alarm means to product said alarm signal upon sensing said pre-selected variation of electromagnetic radiation; and

said alarm system comprising an electronic circuit having a pair of quasi-complementary coupled transistors coupled between said receiving means and said alarm means to provide a high out put to said alarm means notwithstanding substantial impedance mismatching between said circuit and said alarm means.

2. The invention as recited in claim 1 wherein said receiving means comprising a photo-electric cell coupled to said circuit and having electrical properties which vary in response to sensing pre-selected ranges of electromagnetic radiation.

3. The invention as recited in claim 2 wherein said electronic circuit comprises an oscillator actuated by said photo-electric cell; said alarm means comprises a speaker coupled to said oscillator, said oscillator driving said speaker to produce an audible signal upon said photo-electric cell sensing.

4. A wallet alarm device capable of being carried by a person in an enclosure, comprising:

an alarm circuit operative to produce an alarm signal;

a wallet having a pouch for releasably retaining said alarm circuit;

said alarm circuit comprising a photo-electric cell responsive to pre-selected variations in electromagnetic radiation and operative to actuate said circuit to produce said signal upon sensing said variations in electromagnetic radiation upon removal from said enclosure; and

said alarm circuit including alarm means and a pair of quasi-complimentary coupled transistors coupled between said photo-electric cell and said alarm means to provide a high out put to said alarm means notwithstanding substantial impedance mismatching between said circuit and said alarm means.

5. The invention as recited in claim 4 wherein said alarm circuit comprises an oscillator circuit and a speaker coupled to said oscillator; said photo-electric cell coupled to said oscillator circuit and effective to actuate said oscillator circuit upon sensing said pre-selected variations in electromagnetic radiation, and said oscillator circuit operative to drive said speaker to produce an audible alarm signal.

6. The invention as recited in claim 5 wherein said photo-electric cell has electric properties which vary in response to sensing changes in magnitudes of electromagnetic radiation within the visible light range, wherein said oscillator circuit is actuated in response to variation in said electrical properties of said photo-electric cell.

7. The invention as recited in claim 6 wherein said oscillator circuit comprises a charging circuit and a transistor operatively coupled to produce an oscillating electrical output within the audible frequency range.

8. The invention as recited in claim 7 wherein said charging circuit comprises at least one resistor and capacitor, said resistor and capacitor operatively coupled to said transistor and having parameters to effect said output within the audible frequency range.

9. The invention as recited in claim 7 where said pouch includes an aperature disposed to register with said photo-electric cell and said speaker to expose the same to the exterior thereof.

10. The invention as recited in claim 7 wherein said alarm circuit comprise a replacable battery operative to energize said circuit.