CN1650132A - gas lighter - Google Patents

Abstract

A gas lighter, the lighter comprising: a fuel tank (2) made of rigid amorphous polymer material having a top wall (5) with a well (6) passing through it and intended to contain fuel at least partially in liquid phase; a threaded ring (7) screwed into a threaded portion (8) of the tank well; and a gas distribution device (10) comprising at least one tubular element (23) fitted in the threaded ring. The tubular element (23) extends through the threaded ring (7) and has a bottom (24) extending at least as far as the bottom end (6a) of the well and receiving a microporous membrane (25) ensuring a substantially constant gas flow rate.

Description

gas lighter

technical field

The present invention relates to gas lighters.

More particularly, the present invention relates to a gas lighter comprising: a fuel tank of rigid amorphous polymer material having a top wall with a well extending therethrough for a threaded ring screwed into a tapped portion of the well of the tank; and a gas distribution device comprising at least one tubular member fitted in the threaded ring.

Background technique

Rigid amorphous polymer materials have advantages in the manufacture of tanks for gas lighters, and specific examples worth mentioning are styrene acrylonitrile (such as SAN) or acrylonitrile-butadiene-styrene copolymers (such as ABS) class of materials. In practice, such polymers are generally inexpensive and easy to use. Additionally, certain rigid amorphous polymers such as SAN are transparent, which has the advantage of being able to see the level of liquid fuel remaining in the tank.

In general, since such amorphous polymers have low elongation at the elastic limit, typically less than 5%, they are relatively brittle at ambient temperature. Consequently, such polymers cannot withstand tensile stresses, since such stresses would lead to microcracks and thus to gas escape. Additionally, their mechanical properties deteriorate as the material ages.

Such fragility makes it impossible to fit the gas distribution device in the well of the tank by means of a press fit, since such a press fit would create micro-cracks and thus gas escape. For this type of lighter, for example, a gas dispensing device is used which may comprise the following parts (as shown in Figure 8 of PCT application WO 01/18452):

- a core rope 27 extending from the bottom of the tank 3 to a well in the top wall to feed liquid fuel by capillary action to the "wet" chamber;

- a piece of porous foam material 25 having one side in contact with the wet chamber and for enabling evaporation of the liquid fuel;

- a tubular element 12 provided with an annular gasket 31 to ensure a certain degree of sealing between the wall of the well and the wall of the tubular element facing radially outwards;

- a threaded ring 11 screwed into the tapped top of the well, in which the tubular piece of compressed foam fits; and

- A sleeve 13, usually made of brass, mounted to slide over a threaded ring and having a bottom cooperating with the tubular member to form a valve for controlling the gas flow rate.

The main disadvantage of this distribution device relates to the fact that the foam material piece cannot guarantee a constant gas flow rate and thus a constant flame height. The gas flow rate varies inter alia with the internal pressure and temperature of the tank. Thus, the threaded ring is usually provided with a manual control 37 to allow the user to adjust the flame by compressing the foam piece to different degrees. However, when the flame height device is operated accidentally or inadvertently, the flame height may vary considerably.

Contents of the invention

It is an object of the present invention to alleviate these disadvantages.

For this purpose, in the present invention, a lighter of said type is characterized in that the tubular member extends through the threaded ring and its bottom extends at least as far as the bottom of the well and receives a micrometer which ensures a substantially constant gas flow rate. Porous film.

By means of this microporous membrane forming an adjustment means for adjusting the gas flow rate, a constant flame height can be guaranteed. Such microporous membranes are provided with a plurality of pores of a size and angular position such that the gas flow rate can be precisely adjusted regardless of whether the inner side of the membrane is in contact with the gaseous or liquid phase of the fuel. Furthermore, the small size of these membranes facilitates the miniaturization of the lighter.

In addition, the location of the microporous membrane and the location of the bottom of the tubular member also help to ensure a controlled flame height.

In impact tests, when the bottom of the tubular member was positioned at an intermediate position between the top and bottom ends of the tank well, the inventors of the present invention found damage to the microporous membrane that would cause uncontrolled changes in flame height.

Such damage occurs in certain impact tests designed to simulate lighters being dropped from great heights, especially when tanks are made of rigid amorphous polymers such as SAN or similar , a shock wave may be generated in the tank, and due to the rigidity of the tank, said shock wave is completely transmitted to the top of the lighter and guided through the well of the tank to the microporous membrane.

The inventors of the present invention have found that, surprisingly, such damage does not occur when the tubular member is arranged as in the present invention.

In a preferred embodiment of the present invention, in addition, any of the following settings can optionally be used:

- an annular sealing gasket is arranged between the tubular member and the smooth-walled well middle part;

- the well is provided with a radially inwardly extending flange against which the threaded ring holds the annular sealing gasket;

- the tubular member is made of metal;

- holding the microporous membrane against an inner shoulder in the tubular member by pressing the microporous membrane against a retaining ring against which the bottom end of the tubular member is clamped;

- the tank comprises a bowl having a top end to which the top wall is bonded; and

- The storage tank is made of a material selected from ABS and SAN.

Description of drawings

Other characteristics and advantages of the invention can be seen on reading the following description, given by way of non-limiting example and with reference to the accompanying drawings. In the drawings, FIG. 1 is a vertical sectional view of a cigarette lighter according to an embodiment of the present invention.

Detailed ways

The gas lighter 1 shown in Figure 1 comprises a tank 2 for containing a fuel which is pressurized and partly liquid, for example a material such as isobutane.

In the embodiment shown, the tank is formed by a cross-sectionally shaped bowl 3 , the bottom of which is not shown in the figures, and whose annular side walls extend upwards from the bottom to a top end 4 .

The top end 4 is closed by a top wall 5, which in the example shown is a separate part fixed to the bowl 3, for example by gluing.

The entire storage tank 2 is made of at least one rigid amorphous polymer material, for example selected from the group consisting of acrylonitrile-butadiene-styrene copolymers (ABS) and styrene acrylonitrile (such as SAN). For example, the bowl 3 can be made of SAN and the top wall can be made of ABS, and these materials can be bonded together in a known manner, for example by ultrasonic sealing.

The advantage of such rigid amorphous polymers is, inter alia, that they are inexpensive and easy to implement. In addition, some of them, such as SAN, are transparent and allow the user of the lighter to see the level of liquid fuel remaining in the tank.

To accommodate the gas pressure prevailing inside the tank, the bowl 3 and the top wall 5 have relatively thick walls.

The top wall 5 of the bowl 5 is provided with a vertically extending well 6 which may advantageously be circularly symmetrical cylindrical.

A threaded ring 7 is screwed into a threaded portion 8 of the well. In the example shown, it is screwed into the top of the well.

The well 6 receives a gas distribution device 10 actuated by a control device 11 carried by a lighter head 12 located above the tank 2 .

The head 12 also forms a support structure on which an ignition device 14 and a cover 13 forming a barrier against the ventilation air flow are fitted.

Ignition means are well known and, for example, it may comprise a serrated friction wheel 15 and a flint 16 pressed against the saw gear by a spring 17 received in a circular cup 8 in the head 12. 15 on. A complementary cup 19 is formed in the top wall 5 of the tank to receive the cup 18 of the head. However, other types of ignition means may of course be used, eg devices such as piezoelectric means.

In the embodiment shown, the head 12 is held against the top wall 5 of the tank by means of clips 20 thereon which are snap-fastened to complementary clips integrally molded with the top wall 5 of the tank. 21 coordination.

The dispensing device 10 comprises a tubular member 23, advantageously made of metal, having the shape of a circularly symmetrical cylinder. This tubular piece 23 fits in the threaded ring 7 . Fitting therein is preferably by means of a press fit to ensure a good seal and to ensure that the tubular member remains immobile relative to the ring.

The bottom 24 of the tubular member receives a microporous membrane 25 which ensures a constant gas flow rate. The membrane may consist of a uniaxially stretched polypropylene film provided with slot-like holes as described in patent document US 4 496 309.

In the present invention, the bottom 24 of the tubular member 23 protrudes beyond the bottom end 6a of the well. In the embodiment shown, the base protrudes by about 1 mm. Surprisingly, such a configuration made it possible to avoid any damage to the porous membrane even in tests simulating dropping a lighter from a great height onto a hard surface. However, in tests carried out with the bottom 24 of the tubular member terminating in the well 6, it was found that the membrane could be damaged and in some cases even ruptured.

Tests have shown that it is sufficient for the end of the bottom 24 to be flush with the inside surface 5a of the tank top wall 5 to avoid damage to the membrane.

It should be noted that the cup 9 in the top wall 5 can extend towards the inside of the tank without changing the resistance to impact of the microporous membrane.

Preferably, the membrane 25 is held against an inner shoulder 26 of the tubular member 23 formed near the bottom 24 of said tubular member, and the membrane 25 covers an inner shoulder 26 formed at the center of the shoulder 26. holes 27 and the membrane is pressed against the bottom surface of said shoulder by a rigid ring 28 which is itself held at the bottom of the tube by clamping 29 the end of the bottom of the tube.

The dispensing device also comprises a valve formed by a tubular hollow body 31 fitted at its bottom with a closure means, such as an elastomer disk 32, suitable for closing the above-mentioned orifice 27. The hollow body forms a gas outlet duct 33 which communicates with the interior of the tubular member 23 via a slot 34 or similar structure arranged in said hollow body and opening in the vicinity of the ignition means 14 .

The hollow body 31 has an outer side wall which advantageously extends along a substantial part of the inner side wall of the tubular member 23 in order to limit gas leakage when the valve is open. It should be noted that the tubular member 23 advantageously passes through the ring 7 in order to increase the axial length of the outer wall of the hollow body in contact with the inner wall of the tubular member, thus improving the tightness between the tubular member 23 and the hollow body 31 . Furthermore, the tubular member runs through the ring, minimizing the height of the overall dimensions of the dispensing device 10 .

The control device 11 comprises a fork 35 mounted in an inclined position relative to a pin fixed integrally with the head 12 . The first end of the fork 35 cooperates with a recess formed at the top of the hollow body 31 to lift said hollow body when the user presses on the second end 38 of the fork. To keep the valve 24 closed in the rest position, a compression spring 39 is provided between the bottom surface of the second end 38 of the fork and the bottom 40 of a well formed in the top wall of the tank.

In order to make the tank leak-tight, an annular gasket 41 is provided between the tubular member 23 and the middle portion 42 of the smooth-walled well. The quality of the surface condition of the middle portion 42 of the well and the quality of the material used for the annular gasket 41 can be selected to obtain a satisfactory seal to the tank.

Furthermore, the sealing gasket 41 can be held in abutment by the threaded ring 7 against the radially inwardly extending flange 43 of the well, thereby improving the seal. However, the ring gasket cannot be pressed very hard against the flange 43 in order to avoid cracks in the top wall 5 of the tank.

Claims (7)

1. A gas lighter comprising: a fuel tank (2) made of rigid amorphous polymer material, the tank having a top wall (5) through which a well (6) passes , and is used to hold fuel that is at least partially in liquid phase; a threaded ring (7) screwed into a tapped portion (8) of the well of the tank; and includes at least one tubular member (23) fitted in the threaded ring ) of a gas distribution device (10), said lighter is characterized in that the tubular member (23) runs through the threaded ring (7), and its bottom (24) extends at least to the bottom end (6a) of the well, and receives the guarantee A microporous membrane (25) of substantially constant gas flow rate. 2. The lighter according to claim 1, characterized in that an annular sealing gasket (41) is provided between the tubular member (23) and the middle portion (42) of the smooth-walled well (6). 3. The lighter according to claim 2, characterized in that the well (6) is provided with a radially inwardly extending flange (43), and the threaded ring (7) keeps the annular sealing gasket (41) abutting against said Flange (43). 4. The lighter according to any one of claims 1 to 3, characterized in that the tubular member (23) is made of metal. 5. Lighter according to claim 4, characterized in that the microporous membrane (25) is held against the tubular member (23) by pressing the microporous membrane (25) against a retaining ring (28) and the bottom end (29) of the tubular member (23) is clamped on said retaining ring (28). 6. The lighter according to any one of claims 1 to 5, characterized in that the tank (2) comprises a bowl (3) with a top end (4), the top wall (7) being bonded to the above the top. 7. The lighter according to any one of claims 1 to 6, characterized in that the tank (2) is made of a material selected from ABS and SAN.