Lighter With Delayed Gas Release

The present invention relates to a lighter of the type normally used for cigarettes and cigars. More particularly this invention concerns such a lighter using gas as a fuel and equipped with a cutout to prevent operation by a child.

A standard lighter with delayed gas release such as described in U.S. Pat. No. 4,773,849 of F. Schachter and French patent 2,273,992 has a body forming a reservoir filled with a supply of a normally gaseous combustible stored as a liquid, a pressure-reducer/evaporator on an outlet of the reservoir, and a burner/valve that closes the gas outlet. This valve is operated by a lever pivoted about an axis orthogonal to that of the burner/valve and has a front end normally applied against a shoulder of the burner/valve and constantly maintaining the valve closed against a force exerted on it by the gas. The lever also has a rear operating end that is constantly acted on by a spring urging it pivotally in a direction corresponding to closing of the valve, that is pressing the valve shoulder axially downward. Such a lighter is lit by pressing down the rear end of the lever against the above-mentioned spring to free the valve so that it opens under the action of the pressurized gas and so as to operate slightly afterward a mechanism for producing a lighting spark.

It is easy to see that it is preferable that opening of the valve only take place at the end of actuation of the lever, not only in order that gas is only released at the instant of production of the spark in the case that this is after the starting of movement of the lever so as to favor lighting but also in order that the time the valve is opened is reduced as much as possible. Since in addition it is common that such a lighter is squeezed in the pocket of a garment or a bag it is possible that one of the conditions it is subject to tends to tip the lever somewhat in a direction opening the valve and, unless there is a neutral stroke, such tipping inherently leads to a useless loss of gas.

It is also particularly important that the valve only be opened at the end of the travel of its control lever when the lighter is a childproof lighter. Such a device, as described in copending patent application 651,332 filed Feb. 9, 1991, has a mechanism for blocking the control lever in the closed position of the valve that is capable of being maneuvered into an out-of-the-way position in order to permit lighting of the flame but that is automatically returned to the active blocking position after each actuation of the control lever.

This childproofing mechanism comprises movable abutments normally situated in the path of a part of the rear end of the control lever. In order that this mechanism perfectly performs its function it is necessary that it be opposed to any pivoting of the lever, even through a very short stroke, because as soon as it is released by the control lever the valve is pushed into the open position by the pressurized gas freed by the pressure- reducer/evaporator. However, manufacturing tolerances do not allow one to eliminate all play between the control lever and the movable abutments of the blocking mechanism and in addition the progressive deformation of the lever, in particular caused by heat of the lighter flame, tends to increase this play to the detriment of safety.

In French patent 2,280,029 of M. E. Coggiola a lighter of the above-described type is known in which opening of the valve by the control lever is delayed by the use of a second biasing means interposed between the first spring and the valve and set to act on the valve in series and in the same direction as the first spring, that is in the direction of closing of the valve but with a force less than that of the first spring but more than that caused by the pressure of gas and tending to open the valve. Thus when the lighter is in the rest position, that is when the valve is closed, the first spring maintains the second biasing means in maximum activated position, that is compressed, and the sum of the two forces is opposed to opening of the valve. It is only during actuation of the control lever in the direction of opening the valve that the second biasing means continues all alone, to start with, to oppose opening of the valve and it is only on further actuation of the control lever that there is a sufficient deactivation of the second biasing means to allow opening of the valve. Thus the presence of this second biasing means delays opening of the valve by a time corresponding to a predetermined fraction of the angular travel or free path in the closing direction of the valve of the control lever for opening and closing.

In the lighter of the above-cited French patent the second biasing means if formed by the control lever which to this end is shaped to have an elastically deformable section between its front end bearing on the burner/valve and its rear end. The front end of the control lever which completely or partially surrounds the upper end of the burner/valve is divided by a V-section notch into upper and lower sections connected to each other by a web of elastic material forming an elastic hinge. The lower section is normally inclined downward but can be pushed elastically toward the upper section with a force smaller than that caused by the first spring but greater than that caused by the pressure of the gas under the valve. While giving complete satisfaction as far as function is concerned, this lighter has the disadvantage of being expensive because of the price of its control lever.

It is therefore an object of the present invention to provide an improved lighter.

Another object is the provisions of such an improved lighter which overcomes the above-given disadvantages, that is which is provided with a child-safety cutout and a delayed gas release, but that is still inexpensive to manufacture.

A lighter according to the invention has a body forming a reservoir holding a supply of a flammable gas under pressure and a valve on the body openable to allow the gas to escape from the reservoir as a jet extending along an axis and normally urged open by the pressure of the gas. A pressure reducer is provided on the reservoir upstream of the valve and an igniter on the body can light the jet when the valve releases it. An operating lever pivoted on an axis orthogonal to the jet axis has a front end normally bearing axially downward on the valve and a rear end. A first spring braced between the body and the lever rear end rotationally biases the lever front end downward on the valve with a predetermined first force greater than the force exerted oppositely on the valve by the gas. An axially deformable annular element surrounding the burner/valve bears axially upward on the lever front end for exerting on the valve an axial downward force smaller than the first force of the first spring and greater than the opposite gas force.

According to another feature of this invention the annular element forming the second spring means is an elastically deformable ring, for instance a spring-steel washer, fixed on the valve. It can also be a ring of elastically compressible material, for instance of plastic or elastomeric foam, fitted over the valve. In another arrangement the annular element is a coil spring surrounding the valve.

The above and other objects, features, and advantages will become more readily apparent from the following, it being understood that any feature described with reference to one embodiment of the invention can be used where possible with any other embodiment and that reference numerals or letters not specifically mentioned with reference to one figure but identical to those of another refer to structure that is functionally if not structurally identical. In the accompanying drawing:

FIGS. 1 and 2 are partial vertical sections showing the upper portion of the gas lighter according to a simple embodiment of the invention, with the control lever for opening and closing of the burner/valve respectively in the rest position and the closed position of the burner/valve and immediately before opening the burner/valve;

FIGS. 3 and 4 are views similar to FIGS. 1 and 2 showing a variant of this embodiment;

FIGS. 5 and 6 are views similar to FIGS. 1 and 2 showing another embodiment of the lighter.

As seen in the drawing, the lighter has a body 2 formed with two communicating compartments 3a and 3b forming a supply reservoir normally at least partially filled with a gaseous combustible that is stored as a liquid. The upper part of the body 2 of the lighter supports on its front side, to the left in the drawing, a burner/valve 4 centered on a vertical axis 4a and having an upper end 4b movable axially and normally maintained in the lower closed position as illustrated in FIGS. 1, 3, and 5 of the drawing by a control lever 5 for opening and closing the burner/valve 4. A horizontal pivot axis 6 of the lever 5 is carried by a pivot whose one lug 7 is shown in the drawing.

The lever 5 has a front end 5a that is positioned to the left in the drawing and that is formed as a crown so as to surround the upper end 4b of the burner/valve 4 and also has a rear operating end 5b that is continuously subjected to the action of a helical spring 8 compressed between it and the upper part of the body 2 of the lighter. This spring 8, which constitutes the first spring or biasing means of the lighter, tries continuously to pivot the lever 5 in the direction of arrow 9, that is so that its front end 5a maintains the burner/valve 4 closed by pressing against a shoulder 4c of this burner/valve 4. Pressing axially downward on the rear end 5b of lever 5 pivots it in a direction opposite that of the arrow 9 so as to lift the burner/valve 4 to the open position under the effect of gas pressure.

The jet of gas that is emitted along the axis 4a by the valve 4 is ignited by a spark generated by an igniting mechanism here constituted by a standard ridged wheel 1 cooperating with a flint that is not illustrated. Thus when the rear lever end 5b is depressed and the wheel 1 is rotated the gas jet is ignited. As the lever 5 is held in the depressed condition the jet will continue to burn. This lighting mechanism which can be of any type, such as pyrophoric stone, piezoelectric quartz, or the like is set up to be operated at the same time, just before or just after the control lever 5 opens the burner/valve 4.

The force which the lever is continuously subjected to by the spring 8 tends to bend it in a direction corresponding to advancing the moment when the burner/valve 4 opens. In addition heat communicated by the burner/valve 4 to the lever 5 tends to deform it in the same direction. This premature opening of the burner/valve is to be avoided because it is a source of extra useless consumption.

In addition in childproof lighters of this type having underneath the rear operating end 5b of the lever 5 a movable stop serving to limit the pivoting in the direction of opening the burner/valve, requirements of automatic assembly of these lighters plus manufacturing conditions of their component parts make it inevitable that there will be some play between the lever 5 and the movable stops, this play making it possible to open the burner/valve 4 is spite of the presence of the stops. In this case this premature opening is to be avoided at all costs because it completely nullifies the precautions taken with respect to children.

This is why between the first biasing means serving to guarantee closing of the burner/valve 4 and formed in the examples illustrated in the drawing by the helical spring 8 and the burner/valve 4 there is provided a second spring or biasing means serving to create a second closing force for the burner/valve 4, independent of the first one and mounted in series with same in order to act in the same direction, but with a force that is less than that of the first one but greater than that caused by the pressure of the combustible trying to open the burner/valve 4. Thus even when the first biasing means is deactivated by action on the lever 5 serving to pivot it in the direction corresponding to freeing of the burner/valve 4, that is in the direction opposite to that of the arrow 9, the second biasing means assures that the burner/valve 4 is maintained in the closed position right up until it is actuated in turn by the pivoting of the lever 5 in the above-mentioned direction.

Naturally the angular travel of the lever 5 corresponding to opening the burner/valve 4, or the free path, depends on the deflection of the second biasing means corresponding to the balancing of its force with that caused by the pressure of gas upstream of the burner/valve 4. This deflection is easy to determine as a function of the type of the second biasing means.

According to the invention and in order to simplify the fabrication and to reduce the cost of the lighter, the second biasing means is formed by an axially deformable annular element surrounding the upper end of the burner/valve to which it is attached axially and on which it forms a shoulder against which is applied the front end of the control lever which, under the action of the first biasing means, normally maintains the burner/valve closed.

In the examples illustrated in FIGS. 1 and 2 the annular element forming the second biasing means is formed by an elastically deformable washer 11 of spring steel or other appropriate material fixed on the upper end 4b of the burner/valve 4 and having an upper face forming the shoulder 4c against which the front end 5a of the lever 5 is normally pressed by the force of the helical spring 8. In order to obtain a greater deformation of the ring 11 and consequently a longer free travel of the control lever 5, the front end 5a of same is formed with lower bumps 5'a that are diametrically opposed to each other.

The embodiment shown in FIGS. 3 and 4 differs from the first example in that the elastically deformable washer 11 is replaced by a washer 12 of a material that is elastically compressible and preferable nonflammable, such as a synthetic-resin foam or is formed by a helical spring. Functioning of this lighter is directly comparable to that of the first example.

In the example illustrated in FIGS. 5 and 6 the annular element forming the second biasing means is formed by a helical spring 13 surrounding the upper end 4b of the burner/valve 4 and normally compressed between a rigid shoulder 4c of this burner/valve and the front end 5a of the control lever 5.

In any case the force created by the washer 11 or 12 or by the spring 13 is smaller than that created by the spring 8 which deforms it or the maximum compression, but is greater than that created by the pressure of the combustible trying to open the burner/valve 4.