Variable Light Beam Flashlight

The present invention relates to a flashlight, and more particularly relates to a flashlight which can be intermittently turn on and off easily.

Flashlights having variable focus or having variable dispersion light beam are disclosed in U.S. Pat. No. 4,398,238 (Norman C. Nelson, "Variable focus flashlight", Ser. No. 303,418, filed Dec. 4, 1981) and U.S. Pat. No. 4,819,141 (Anthony Maglica, "Flashlight", Ser. No. 43,086, filed Apr. 27, 1987). The mechanism for producing light beam having variable dispersion are relatively complicate. Besides, no flashlights can be turn on and off intermittently.

The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional flashlights.

A primary objective of the present invention is to provide a flashlight which can be intermittently turned on and off easily.

Another objective of the present invention is to provide a flashlight whose structure is relatively simple and effective.

Further objects and advantages of the present invention will become apparent from a careful reading of the detailed description provided hereinbelow, with appropriate reference to the accompanying drawings.

FIG. 1 is an exploded perspective view of a flashlight in accordance with the present invention;

FIG. 2 is a cross-sectional view of the assembled flashlight of FIG. 1; and

FIG. 3 is a cross-sectional view similar to FIG. 2, illustrating that an electrical circuit of the flashlight is close.

Referring to FIGS. 1 and 2, the flashlight in accordance with the present invention generally comprises a cylindrical tube 1, a control ferrule 2, a slidable socket 3, a face cap 4, a tail cap 5, a sleeve 6, and batteries 7.

A reduced diameter portion 11 with an outer thread substantially occupied half the length thereof is formed at a front end of the cylindrical tube 1, and an inner thread 12 is formed in the rear end of the cylindrical tube 11. The batteries 7 are disposed within the cylindrical tube 1. A pair of opposite oblong openings 14 are formed on the reduced diameter portion 11. The control ferrule 2 with an inner helical groove or inner thread, e.g., round thread, is freely rotatably provided on the rear half of the reduced diameter portion 11 without thread. The slidable socket 3 has two longitudinal grooves 31, 32 for receiving a respective conductor 72 or 74. Two prongs 78 of a light bulb 76 are respectively inserted into the grooves 31, 32 to contact the conductors 72, 74. A free end of the conductor 72 is folded to bear against a bottom surface of the slidable socket 3 in order to be engaged with a center electrode of an adjacent battery 7. A transverse hole 33 is formed in the slidable socket 3. A guide means, such as a pin 8 penetrates through the oblong holes 14 and the transverse hole 33 so as to slidably hold the slidable socket 3. The longitudinal movement of the slidable socket 3 or the pin 8 is limited by the oblong holes 14. Both ends of the pin 8 are engaged in the inner thread of the control ferrule 2. The pin 8 is forced to move up and down along the oblong hole 14 by a relative rotational movement between the control ferrule 2 and the front end 11 of the cylindrical tube 1 so that the slidable socket 3 can slidably move up and down by means of the pin 8.

A parabolic reflector 82, a lens 84 and a sealing ring 86 are disposed in a front end of the face cap 4. The cap 4 with an annular inner flange 42 is threadedly engaged on the front end of the reduced diameter portion 11 until the annular flange 42 contacts the most forward end surface of the portion 11. Two longitudinal ribs 62 are oppositely formed in the sleeve 6. A short cylinder 52 with a pair of opposite slots 53 and an annular groove 54 is integrally formed on one end of the tail cap 5 so that an annular surface 56 is formed. The sleeve 6 which is generally made of insulating materials is engaged on the short cylinder 52 with the ribs 62 respectively engaged within the slots 53. The movement of the sleeve 6 on the short cylinder 52 is limited by a retaining ring 64 which is engaged with an inward flange 65 on the annular groove 54 of the tail cap 5. A small gap exist between the sleeve 6 and the tail cap 5 so that the sleeve 6 can move longitudinally on the short cylinder 52 for a small distance. The tail cap 5 is engaged on the rear end of the cylindrical tube 1 by means of the threaded engagement between the outer thread of the sleeve 6 and the inner thread 12 of the cylindrical tube 1.

Referring again to FIG. 2, the face cap 4 is disposed on the front end of the portion 11. The pin 8 is moved to a position near the top of the oblong hole 14. At this position, the foremost battery 7 bears against the shoulder between the reduced diameter portion 11 and the cylindrical tube 1; and the conductor 72 still contacts the center electrode of the adjacent battery 7. The tail cap 5 and the sleeve 6 are engaged with the sleeve 6 in the rear end of the cylindrical tube 1. The sleeve 6 is not completely threaded into the tube 1 so that a small gap separates the tail cap 5 and the sleeve 6. At this position, the annular surface 56 of the tail cap 5 does not contact the rear end of the cylindrical tube 1. The electrical circuit of the flashlight is open because the gap separates the tail cap 5 and the sleeve 6. The tail cap 5 is electrically connected to the case electrode of a rearmost battery 7 through the short cylinder 52 and/or the retaining ring 64 and the spring 66; and the cylindrical tube 1 is electrically connected to the center electrode of the foremost battery 7. When a pressure is applied to the tail cap 5 to push it forward, the annular surface 56 of the tail cap 5 contacts the rear end of the cylindrical tube 1 so that the electrical circuit of the flashlight is completed. Therefore, intermittently pressing the tail cap 5 produces an intermittent lighting of the light bulb 76 so that a signal can be easily signaled by the flashlight. Further rotation of the control ferrule 2 makes the socket 3 to move toward the front end of the flashlight so that the electrical connection between the conductor 72 and the center electrode of the nearest battery 7 can be separated so that the electrical circuit of the flashlight is open.

Referring next to FIG. 3, the tail cap 5 is completely threaded onto the cylindrical tube 1 so that the annular surface 56 of the tail cap 5 permanently connects the rear end of the cylindrical tube 1. Therefore, the electrical circuit of the flashlight is closed, and the light bulb 76 is on. A rotational movement of the control ferrule 2 makes the pin 8 move rearward along the oblong hole 14. Therefore, the socket 3 is pushed rearward by the pin 8 to rearward push the batteries 7. Consequently, the light bulb 76 longitudinally slides relative to the reflector 82 so as to produce a variable dispersion of the light beam.

Referring again to the drawings, normally, the outer surfaces of the cylindrical tube 1 and the tail cap 5 are applied with insulating materials except two ring portions 10, 50 respectively provided on the outer surfaces of the cylindrical tube 1 and the tail cap 5. The ring portion 10 electrically connects to the center electrode of the foremost battery 7 via the cylindrical tube 1 and the conductors 72, 74 and the light bulb 76. The other ring portion 50 connects to the casing electrode of the rearmost battery 7 via the tail cap 5 and the spring 66. When the sleeve 6 is not fully threaded into the rear end of the cylindrical tube 1, the spring 66 permanently urges the tail cap 5 rearward so that a gap is formed between the annular surface 56 of the tail cap 5 and the rear end of the cylindrical tube 1. Therefore, the electrical circuit of the flashlight is open. The ring portions 10, 50 can be respectively connected to the two electrode of a power supply of a charging apparatus (not shown) so as to recharge the batteries 7 without taking the batteries 7 out of the cylindrical tube 1. Alternatively, a ring portion 40 which is provided on the outer surface of the face cap and one of the two ring portions 10, 50 are connected to a power supply if the tail cap is electrically connected to the cylindrical tube and the conductor 72 is not connected to the center electrode of the battery 7.

Accordingly, the flashlight in accordance with the present invention has the following advantages:

(a) The light bulb 76 of the flashlight can be turned on and off intermittently in order to signal a signal.

(b) The structure of the flashlight is relatively simple and effective. The cost is thus reduced.

(c) The batteries of the flashlight can be recharged easily without the need to take it off.

While I have described a preferred embodiment of the present invention, numerous modifications, alterations, alternate embodiments, and alternate materials may be contemplated by those skilled in the art and may be utilized in accomplishing the present invention. It is envisioned that all such alternate embodiments are considered to be within the scope of the present invention as defined by the appended claims.