Battery Ignitable Cigarette Lighter

1. Field of the Invention

The present invention relates to a pocket, battery ignitable lighter and particularly to a switch mechanism in the ignition circuit for safely operating the lighter.

2. Description of the Prior Art

In a known type of a battery ignitable lighter, it is usual to provide a switch button for igniting a gaseous fuel. The switch is located on the exterior of the casing of the lighter and thus, inherently possesses the danger of an unwanted operation thereof.

It is therefore an object of the present invention to provide a battery ignitable lighter in which a switch is designed to prevent unwanted operation.

It is another object of the invention to provide a battery ignitable lighter in which a switch is arranged inside a lighter cap to prevent problems caused, for example, by dust, dirt or the like from the outside of the lighter.

It is a further object of the present invention to provide a battery ignitable lighter in which, when the lighter cap is opened, a switch is designed to project outside the casing so as to be easily actuated.

In the lighter according to the present invention, an ignition circuit of the lighter is operated by a switch which is arranged in the lighter cap and is designed to be outside the casing when the lighter cap is opened. Thus, the switch can not be actuated in the closed position of the lighter cap. Therefore, this lighter offers safety in the actuation of the lighter due to unwanted operation.

By way of example only, a preferred embodiment of the invention will now be described with reference to the accompanying drawings, in which:

FIG. 1 is an elevational view in section of an embodiment of a battery ignitable lighter according to the present invention.

FIG. 2 is an upper side view in section of the lighter of FIG. 1.

FIG. 3 is an upper elevational view in section of the lighter of FIG. 1 with the lighter cap in an open position.

FIG. 4 is an upper side view in section of the lighter of FIG. 3.

FIG. 5 shows an actuator of a switch of the lighter shown in FIG. 1.

FIG. 6 is a cross-sectional view taken on line A-A of FIG. 5.

FIG. 7 shows the actuator of FIG. 5 in the actuated position.

FIG. 8 is an exploded view in perspective of the switch means of the lighter shown in FIG. 1.

FIG. 9 is a circuit diagram used in the lighter of FIG. 1.

Referring to FIG. 1, there is shown an embodiment of a battery ignitable lighter comprising a lighter casing consisting of a casing 1 and a lighter cap 2; and a fuel tank 4 within the casing 1 having a burner valve 3. A wind shield 32 covers a burner nozzle 30 and switch means 12 is arranged above the opening 1a of the casing 1 and is fixed on a pillow 33 provided on the fuel tank 4 through a fixing axis 34. A circuit housing 7 is arranged side by side with the fuel tank 4 with an ignition circuit therein and a cell chamber 6 is provided for receiving a cell 5, as for example a mercury cell or silver oxide cell, therein. In an inner recess 8 of the casing 1, a supporting frame 9 is mounted such as shown in FIG. 8. The supporting frame 9 includes right and left side guide portions 10 having guide openings 10a for guiding the lighter cap 2 and supporting posts 11 for supporting an electrode support 29.

In FIGS. 2 to 8, a switch 12 for the ignition circuit is arranged between the guide portion 10 and the supporting post 11. The switch comprises a metallic switch cover 16 having first and second through-bores 13 and 14, a switch lever 22 made of metal, and an insulating member 18 which is arranged between the switch cover 16 and the switch lever 22 for providing insulation therebetween and for supporting the switch lever 22 through a lever axis 21. The switch lever 22 is pivotally mounted on the lever axis 21 in a supporting portion 19 of the insulating member 18 and is electrically connected to the ignition circuit through the lever axis 21 and a lead wire 20. A lever spring 23 around lever axis 21 is arranged to urge the switch lever 22. The first through-bore 13 of the switch cover 16 is used to fix the insulating member 18. The second through-bore 14 is used for an axis 15 by which switch cover 16 is rotatably fixed between the guide portion 10 and the supporting post 11 of the supporting frame 9.

A return spring 24 is arranged around the axis 15, one end of which engages fixing pin 17 and the other end of which engages the supporting frame 9 whereby the switch 12 is always urged inside the casing 1.

As shown in FIGS. 1 and 3, a telescopic cyclinder 25 is positioned under the switch means 12 to promote the movement of the lighter cap 2. The telescopic cylinder 25 engages a cap axis 26 of the lighter cap 2 and a supporting axis 27 is fixed in the side walls of the supporting frame 9 at the left and right ends thereof respectively and functions as a cap controlling means. A valve manipulator 31 engages a U-shaped cutout 9a of the supporting frame 9 and the telescopic cylinder 25 at the right and left ends thereof respectively and also engages a shoulder portion 30a of the burner valve 3. The telescopic cylinder 25 depresses the burner valve 3 through the valve manipulator 31 against the force of a valve spring arranged within the burner valve 3 so as to close the valve in the closed position of the lighter cap 2. The telescopic cylinder 25 also pushes the switch means 12 against the force of the return spring 24 so that the switch lever 22 moves outside the casing 1 in the open position of the lighter cap.

FIG. 9 shows and ignition circuit of the present invention which comprises a cell E whose positive pole is grounded, and switch SW is connected to the positive pole of the cell. A DC--DC converter I is provided which includes a transistor Tr, a transformer T1, and a rectifier D1. A triggering circuit is connected to the DC--DC converter, the triggering circuit comprising a zener diode D2 and resistor R. A discharge circuit comprising a capacitor C, a step-up transformer T2, and SCR D3, and ignition electrodes IE is connected to the triggering circuit.

The DC--DC converter I comprises a conventional blocking oscillator in which the transistor Tr functions in a known manner as a high-speed switch or vibrator. The current through the emitter-collector circuit is dependent on the current through the emitter-base circuit. Thus, if the bias voltage on the base drops to zero or becomes negative, current through the emitter-collector circuit is cut off. In other words, emitter-collector current is controlled by the bias voltage on the base. In this circuit, the emitter and collector are connected to the primary of the transformer T1 through the cell E, while the base is connected to the cell E through a resistor R1 and a feedback winding L. When the switch SW is closed, the fixed bias voltage on the base of the transistor permits a surge of current through the primary and as a result, a voltage is induced in the feedback winding L. This induced voltage reacts with the fixed bias voltage to change the voltage on the base of the transistor Tr. As a consequence, current in the emitter-collector circuit is affected and this, in turn, causes a change in the induced feedback voltage. As a result of these fluctuations, a pulsating DC current is set up in the primary which induces a high voltage in the secondary winding. In this way, the DC--DC converter I changes the cell voltage from a lever of a few volts to a level considerably greater. The half-wave voltage obtained through the DC--DC converter changes the capacitor C to a predetermined level and the zener diode breaks down to trigger the SCR D2 into a state of conduction to allow the capacitor C to discharge through the primary winding of the step-up transformer T2. The resultant current flow causes a high voltage pulse output from the secondary winding of the step-up transformer T2 which causes the ignition electrodes IE connected across it to spark over to ignite the fuel of the lighter.

In operation, when the lighter cap 2 is opened through the extending force of the telescopic cylinder 25, the burner valve 3 is opened to issue the fuel by the force of a spring (not shown) arranged in the valve at the predetermined point of the upward movement of the telescopic cylinder 25 where it ceases to depress nozzle 30 downward through the valve manipulator 31. At the same time, the cylinder 25 pushes the rear portion of the cover member 16 so that the switch lever 22 may appear outside the casing 1. Then the switch lever 22 is rotated horizontally at a small angle about its lever axis 21 to bring it into contact with the portion of the switch cover 16 thereby to close the ignition circuit. As long as the switch is closed, the spark discharge sequentially occurs at the ignition electrodes IE which are formed by the burner nozzle and the discharge electrode to form the spark gap in the above-mentioned operation.

The present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore to be embraced therein.