EP0074956B1 - Liquid gas operated lighter, particularly pocket lighter - Google Patents

Abstract

The lighter comprises a valve connected with a burner head and arranged at the outlet of a drilling (11) of the valve and a fuel container. A non adjustable dimensioning device for the height of the flame is located between the container and said drilling. This device is provided with a metering disc of porous material, pervious to the fuel, this disc being pressed to the side of the fuel container by a piece having a flow opening for the fuel, on the other side, and on its edge, the disc is sealingly pressed against an annular surface, having preferably the shape of a circular crown. The annular surface (13) contains a hollow (16) which, with the metering disc (14), forms a metering volume (16) which communicates exclusively with the head of the burner (4) by the drilling (11) of the valve. The face (2') of the hollow (16) is provided, partially or completely, with a structure formed by prints, optionally bossings, thereby communicating the metering volume (16) with the drilling of the valve. On this face (2') of the hollow the valve is arranged in an open position, the metering disc with its microscopic pores consists of a microporous lamella so as to close more and more the pores, as the pressure differential increases in relation to the temperature.

Description

The invention relates to a lighter operated with liquefied petroleum gas, in particular a pocket lighter, which comprises a closable valve connected to a burner head at the outlet of a valve bore, a fuel tank and an adjustable measurement device for the flame height arranged between the fuel tank and the valve bore, which has a fuel-permeable metering disc made of porous material Material is provided, which is pressed on its side facing the fuel tank by means of a component having a passage opening for the fuel in its edge region tightly against an annular, preferably circular surface which encloses a recess.

Another object of the invention is a method for producing a lighter of the type mentioned above and includes a computer or microcomputer-controlled measurement as an integral method step.

A lighter of the type mentioned is known from FR-A-2397599. This known lighter is a further development of the lighter known from FR-A-2313638, the maximum throughput being limited upwards by providing elastically deformable components upstream of the porous metering membrane, which cover parts of the porous membrane and thus the flow through this membrane limit.

In the case of the lighters known hitherto, production variations occur which cause larger deviations in the flow rate of the fuel from the desired value within a series. Furthermore, it has so far been accepted that as the temperature increases, the influence of the gas vapor pressure has a proportional or even stronger than proportional effect on the flame height. Since the production spread of the metering disc material and the temperature influence overlap, the user is often surprised by an unexpectedly high flame. This is a major safety issue as a user fright could cause accidents. Therefore, even the majority of the disposable lighters on the world market at the cheapest prices have a mechanism that allows the owner to regulate the flame height. This significantly increases the cost of production, and still does not solve the safety problem, since the need to reduce the flame is only recognized after the startling reaction. Various states are therefore considering introducing legal restrictions on pocket lighters, whereby maximum flame heights must not be exceeded. In mass production of lighters without a flame control device, it is therefore an important problem to keep the flame height under control in such a way that it does not deviate by more than - 10% from a setpoint under the same temperature conditions. As a result of the temperature dependency of the vapor pressure, however, the amount of gas flowing out and thus the flame height increase unavoidably with increasing temperature, the flame height also having to comply with the legal regulations at the highest vapor pressure to be expected in practical use.

At a height of 25 mm at 25 ° C and 2.5 bar pressure when using isobutane gas. assumed normal flame, for example in the case of known lighters, the pressure increases to 5 bar when the temperature rises to 50 ° C. Due to this, as well as an additional, non-linear, increased metering disc permeability caused by thermal expansion, the flame increases to 50 to 70 mm. If you define the change in flame height at a defined change in temperature as a flame index, and arrange it. with an increase in temperature from 25 ° to 50 ° C, an increase in flame from 25 to 50 mm to index value 1, an increase in flame from 25 to 70 mm would correspond to a flame index of 1.8.

Experience has shown that, in the case of known small burners, aging in the unused state also causes an irreversible change in the originally set flame characteristic. This is particularly the case when they are exposed to changing or extreme environmental conditions and the clamping elements for the metering disc are made of materials with different thermal expansion.

Flickering of the flames can also often be observed. This applies in particular to pocket lighters, which are often exposed to very different temperatures and are usually in completely undefined transport positions immediately before use.

Some of these shortcomings are not as disadvantageous in pocket lighters which are provided with a flame regulating device as in lighters in which an unadjustable measuring device for the flame height is provided.

Flame regulators are known, US-A-3766946, in which an elastic body against a porous body, e.g. B. sintered metal, can be pressed and deforms itself depending on the size of the contact pressure and creates a larger or smaller surface area on the porous body and thus changes the flow cross section in the porous body.

It is also known to use a porous membrane for the controlled limitation of the gas flow. Such devices are disclosed in FR-A-2 313 638 (with flame regulator) and FR-A-2 313 639 (without flame regulator). In one Between the liquid gas tank and the burner, the metallic valve body is inserted on the side facing the liquid gas tank, the porous membrane, which is covered at least on the side facing away from the tank with a fiber layer, and is arranged gas-tightly clamped in the valve body by means of a pressure body consisting of poorly heat-conducting plastic material. The device is based on the idea that, for a satisfactory function, the side of the membrane facing the liquid gas tank should be constantly filled with the liquid phase of the gas in an exempted area, and that this liquid gas flows through the pores of the membrane to the other Evaporate the side of the liquefied gas tank with the participation of the fiber layer. For this purpose, a wetting chamber is provided on the side of the membrane facing the tank, to which liquid gas is continuously supplied from the liquid gas tank via an immersion tube. An evaporation chamber is provided on the side of the membrane covered with the fiber layer, in which the evaporation takes place when the shut-off valve located above it is opened. In order to avoid evaporation in the wetting chamber and thus a flickering, restless burning of the flame, it is proposed in the above-mentioned FR-A-2 313 639 to produce the pressure body from a poorly heat-conducting plastic material.

This disclosed device does not produce fully satisfactory results by adding together several factors influencing the amount of gas actually let through, such as the inevitable fluctuations in the porosity of the membrane material and the structural scattering of the fiber material, and by the deformation of the wetting chamber diameter as a result of the contact pressure when installing the device . In addition, the dip tube can form vapor bubbles in the liquid column, which, for. B. caused by changing the position of a pocket lighter, do not rule out, which among other things, a flickering of the flame or a sudden diminution of the flame occurs. To improve the latter circumstance, a precision wick is therefore used in practice in the known lighters instead of the dip tube, the manufacturing costs being significantly increased by the high cost of the wick. Despite this increase in price, the differences in the flame height are still unsatisfactory, since the space encompassed by the evaporation chamber and the valve bore has a relatively large volume, and the liquid gas collecting there is therefore responsible for a dangerously high, albeit very brief, flash flame immediately after ignition . This applies in particular to the lighter according to FR-A-2 313 638, whose membrane porosity is matched to a relatively high flame, which is appropriate in such lighters with a flame control device.

When using an immersion tube or a precision wick, a voluminous, poorly heat-conducting plastic part of great rigidity is required for fastening the same and for clamping the membrane. As a result, the dimensions of the metal part surrounding it become relatively large. The large volume of the required parts causes relatively high manufacturing costs.

Due to the differences in thermal expansion between the plastic material proposed for the pressure body due to its poor heat conduction and the metallic valve body receiving it, the clamping forces acting on the membrane change with temperature and can experience irreversible weakening. The use of ultrasound to cut out the metering disc from a film and then fasten it to the clamping body, then insert this preassembled unit into the deep blind hole of the metallic valve body and gas-tight flaring is difficult and can easily result in faulty valve units, which then lead to unusable rejects are.

The generic FR-A-2397599 is, as mentioned, a further development of the aforementioned FR-A-2 313 638, but is only able to limit the maximum throughput but does not guarantee a constant gas passage.

The present invention has for its object to provide a device that enables better constancy of the gas passage. When using the device for lighters, the flame index should be less than 0.9 and the flash of the flame should be avoided, which increases safety and improves the economic use of the fuel. The invention should also ensure a substantial reduction in the tendency of the flame to flicker, enable a significant reduction in manufacturing costs, and moreover the device according to the invention should be easier to assemble than the previously known solutions.

This is solved in the lighter of the type mentioned above in that the recess with the metering disc forms a metering chamber which is connected to the burner head exclusively by means of the valve bore and the end face of the recess in whole or in part with a permanent connection between the metering chamber and valve bore maintaining structure, which has depressions and optionally elevations, to which, when the valve is open, the microscopic single-pore metering disc made of microporous film with increasing pressure difference, which is temperature-dependent, closes more and more pores, is applied.

In an advantageous manner, the structure of the end face contains radially extending grooves with a wedge-shaped cross section, which subsequently have peaks on their side edges, wherein the depth of the grooves based on the surface level of the unstructured surface areas (anti-glare surfaces) is a multiple, preferably five to twelve times the height with which the projections tower above this surface level.

The metering disc is provided with a very large number of submicroscopic, closely adjacent, preferably non-contiguous pores of slit-shaped cross section, and preferably consists of a material which, when the device is used, has its temperature-proportional properties within a temperature range from minus 30 ° to plus 70 ° C maintains fuel permeability unchanged.

Several embodiments of the invention are illustrated below with the aid of the drawings, without restricting them to these embodiments.

Fig. 1 shows a partial section through a lighter, which is equipped with a measuring device according to the invention. For the sake of clarity, all parts that are not essential for the explanation of the invention are not shown. FIG. 2 shows a view of the metering space from below, on a larger scale, with the clamping disk and the metering disk removed, the FIG Section along the line III-III in Fig. 2 on a larger scale, Fig. 4 shows a longitudinal section of part A of Fig. 1 on a larger scale. 5, 6 and 7 represent longitudinal sections through different embodiments of the dimensioning device according to the invention, FIG. 1 shows a testing and flanging device.

In Fig. 1 that part of a lighter is shown in cross section, which receives the measuring device according to the invention to achieve a constant flame height. A valve body 2 is pressed gas-tight into the upper wall of the liquid gas tank 1 and receives a displaceable burner tube 3 in a bore on the side facing away from the liquid gas tank. The burner tube 3 has at its upper end a burner head 4, under which an operating lever 5 engages. The burner tube 3 is penetrated through an axial gas outlet bore 8 opening into the burner nozzle 6 up to a transverse hole 7. At the lower end of the burner tube 3, an elastic sealing disc 9 is arranged, which cooperates with a valve seat 10 of the valve body 2. When the lighter is not in use, a spring (not shown) presses the burner tube 3 down against the valve seat 10 and thus closes the valve bore 11.

On the side facing the liquid gas tank 1 of the valve body 2, which preferably consists of Ms 58 with approx. 2% lead, a blind hole-like recess 12 is expediently machined, in which a metering disc 14 is pressed by a clamping disc 15 against a preferably flat annular surface 13 of the recess 12 is that the metering disc 14 is compressed to about half its thickness and thereby the clamping surface is gas-tight. The clamping disk 15 and the metering disk are fixed in this state by flanging the edge 2a of the valve body 2.

The clamping disc 15 has, at least in the clamping region, a surface which geometrically matches the annular surface 13 and which ensures gas-tight clamping of the edge of the metering disc, and is connected to the liquid gas tank 1 via a gas passage opening 17.

The recess 12 in the valve body 2 is provided with a recess 16, the end face 2 'of the annular surface 13 of the recess 12 a distance of z. B. 0.1 mm. The side of the metering disk 14 facing away from the liquid gas tank 1 forms with the recess 16 a metering space, the depth of which is two to eight times, preferably three to four times the thickness of the metering disk 14. The cross section of the metering chamber 16 perpendicular to the axis of the metering disk 14 determines the size, position and shape of the area of the metering disk 14 which can be acted upon by the fuel. In general, this area will be a circular area. But it can also have a different shape. In the latter case, the diameter of an equally large circular area is referred to as the hydraulic diameter of the area deviating from the circular shape.

The gas passage opening 17 in the clamping disc 15 must be smaller than the hydraulic diameter of the metering chamber 16. The thickness of the clamping disc 15 is smaller than the hydraulic diameter of the metering chamber 16, preferably less than a third of the hydraulic diameter.

It is advantageous to design the clamping disk from a metallic material, preferably from what is known as automatic brass - an alloy of 58% Cu, 2% Pb, rest Zn - since the metering disk 14 is reliably clamped due to the high pressure rigidity of such materials. The valve body 2 is preferably also made of the same material, so that the thermal expansion of the parts surrounding the membrane remains the same when exposed to different temperatures.

The metering disc 14 consists of a microporous plastic film, the transport of liquid gas in the liquid and / or gaseous phase through the disc taking place essentially perpendicular to the surface. In particular, a microporous, uniaxially stretched polypropylene film with a thickness between 15 and 40 micrometers, preferably between 22 and 27 micrometers, and with slit-shaped pores with a cross section of approximately 0.04 by 0.4 micrometers, which are formed in the extrusion direction during the stretching, are suitable. At a gas vapor pressure of 1 to 6 bar, the amount of fuel flowing through is essentially linear to the pressure. Such a product z. B. currently marketed by Celanese Plastics Company, SC, USA, under the brand name «Celgard ^R 2500.

The valve body 2 is structured in FIGS. 4 and 5 on the end face 2 ', which forms the base of the metering space 16, with the exception of a peripheral region 23. The structure 22 can have any relative elevations and depressions. The structure can advantageously consist of radial grooves 21. 2, a four-armed slot star is shown as an exemplary embodiment. However, it is within the scope of the invention to choose any number of arms. For example, five, six or eight arms can be provided. These grooves 21 are preferably embossed in a single stamping process, u. by means of an embossing tool, which has a plurality of wedge-shaped cross-sections, corresponding to the number of cups, arranged in a radial manner. As shown in FIG. 3 on an enlarged scale, the depth 1 of the grooves 21 can be 0.09 mm, the opening a width k of 0.14 mm and the root m 0.03 mm. The raised edge regions 22, which adjoin the edges of the grooves 21, are somewhat rough, since the structure of brass (with about 2% lead for good machinability) breaks open somewhat when it is dipped away, i. H. the grain structure is disturbed. The resulting height n is approximately 0.01 mm. However, the slot star can also be embossed by means of an embossing tool which has at least one cutting edge, the embossing tool being rotated about its longitudinal axis at a defined angle between the individual embossing processes until the desired number of arms is formed.

Of course, other manufacturing methods, e.g. B. etching, sandblasting, electroerosion or the like can be used.

The task of the diameter of the metering chamber 16 is to clear a defined cross section of the metering billets for the gas passage. The depth of the metering chamber 16 is so matched to the flexibility of the elastically deformable metering disk 14 that the desired amount of gas is let through. For example, the depth of the metering space can be matched to the unstructured surface area 23 such that if the gas pressure in the tank increases due to the temperature rise and the membrane contacts the area 23, a proportion of the pores that increases proportionally with increasing pressure is blocked, which is further reinforced by the thermal expansion of the membrane material. The flame height increases to a lesser extent than the increase in gas pressure would otherwise have caused. The flame index can thus be kept below 0.9. With a thickness of the metering disc material of 25 micrometers, for example, a depth of the metering chamber 16 of 0.08 to 0.12 mm is advantageous, with a diameter of 1.8 to 1.9 mm of the metering chamber and a star diameter of 1.3 mm . The above information relates to a quality of "Celgard ^R 2500 _" whose porosity gives a measured value of 7.5 Gurley seconds, according to ASTM test method D-726, model B.

Due to its small thickness, the metering disc 14 is flexible, so that it dodges in the direction of the valve bore 11 due to the flow pressure and thereby lies against the end face 2 '. At higher temperatures and increasing pressure, due to their thermal expansion coefficient, an increasingly larger part of the metering disc 14 also lies on the non-structured area 23 of the end face 2 'without the material's yield strength being exceeded, as a result of which a portion of the pores is blocked , which is larger than a proportional portion, while the grooves 21 and the structure 22 allow the gas to flow into the valve bore 11. After returning to normal pressure, the membrane lifts again from the anti-glare region 23, after which the flow rate again corresponds exactly to the original one, since, with the correct design of the conditions, no irreversible stretching and thus change in the porosity has taken place (FIGS. 3 and 4).

A device according to the invention for a lighter burner results when using a "Celgard ^R 2500 _" membrane with a Gurley measured value of 7.5, installed in a valve body with an outer diameter of 3.5 mm, a clamping disk with an outer diameter of 3 mm and a metering space with a diameter of 1.8 mm, a depth of 0.1 mm and a six-armed star with a diameter of 1.3 mm, at 25 ° C ambient temperature a flame height of 25 mm (normal flame), with about 1 milligrams of fuel per second A change in the metering chamber diameter causes a proportional change in the flame height, which means that if the membrane material corresponds exactly to the desired value, a different flame height can be achieved or a corresponding one can be achieved after a deviation in the Gurley value of the membrane material batch to be used Dosing chamber diameter can be determined to achieve a desired flame height.

Surprisingly, the device according to the invention for the liquid and the gaseous phase of the gas tank filling does not have a very large difference in weight of the amount of fuel passed.

The lighters according to the invention without an immersion tube or wick therefore permit oblique handling (for example for the purpose of lighting a tobacco pipe), the flame only becoming insignificantly larger despite the liquid tank contents coming into contact with the gas passage opening 17.

A calm and uniform burning of the flame in the normal upright operating position is further achieved by an arrangement of the measuring device, which means that the metering disc 14 is in direct contact with the excludes liquid phase of the container filling. When the lighter is lit from an undefined, for example lying, transport position into an upright position, the liquid fuel flows down to a residual amount retained by surface forces from the space in front of the metering disc 14 into the container 1, so that the metering disc 14 is separated from the liquid level 24 of the fuel.

Since the thickness of the clamping disc 15 is not greater than the hydraulic diameter of the metering space 16, the volume of the upstream space is small. Since the low surface tension and viscosity of the liquid phase of the fuel mean that the flow resistance during the outflow is low, the residual amount of fuel that may be retained, based on the cross section of the metering disc available for gas passage, is so small that it can be e.g. B. runs off, evaporated or burned in about 1 second. If a spontaneous, bubble-forming boiling of liquid fuel occurs at all on the side of the metering disk 14 facing the container 1, the amount available for this is evaporated after a short time. The gas passage through the metering disc 14 therefore takes place, apart from a very short start-up time, exclusively from the gaseous phase of the fuel, as a result of which a calm and evenly burning flame is achieved.

The effect can easily be enhanced by various measures.

The most complete possible drainage of the liquid phase when the burner is erected is favored if the surface of the clamping disk 15 is not equipped to be wettable. This can be done, for example, by coating with fluorinated hydrocarbon compounds, for example polytetrafluoroethylene.

If the clamping disk 15 is not wettable, it is advantageous to make the diameter of the gas passage opening 17 so small in relation to the hydraulic diameter of the metering chamber 16 that capillary forces promote the outflow of the fuel from the metering chamber 16 and only small residual amounts of the liquid phase can remain . The space of the gas passage opening 17 is not filled with liquid gas at all, since if the valve, as usual, was still closed when the lighter was in the upright position, no liquid gas would get into the opening, even with any pocket position that followed.

However, if the clamping disc 15 has a wettable surface, the effect according to the invention can be enhanced if the opening 17 is designed geometrically in such a way that capillary effects are avoided.

The stabilization of the flame after ignition also takes place particularly quickly if the valve body 2 projects into the liquid gas tank in such a way that the size of the projection corresponds approximately to the depth of the depression 12, so that the metering disc 14 is approximately in the plane of the liquid gas tank cover 20 of the liquid gas tank 1 lies.

While a preferably inventive design effects the intended effect by dosing from the gas phase. the previously known solutions strive for the most complete and constant wetting or exposure of the porous membrane to the liquid phase. Due to the thermodynamic conditions, boiling with spontaneous or periodic bubble formation cannot be avoided, even if, according to the proposal of FR-PS-2 313 639, the pressure body is designed to be heat-insulating. A flame index of 1.1 to 1.3 is expected.

The saturation vapor pressure of the liquid gas depends on the use of e.g. B. Iso-butane not from the level of the liquid gas tank 1. Since the present invention extracts the gas from the gaseous phase of the tank filling, its effect is completely independent of the filling level of the liquid gas tank 1.

Further advantageous embodiments of the invention are explained with reference to FIGS. 5 to 7, each of which represents a cross section through the lower part of the valve body 2 in the region of the depression 12. All reference numbers are chosen in accordance with FIG. 1 and FIG. 2.

1, the metering chamber 16 is formed by a recess in the recess 12, in the embodiment according to FIGS. 5 and 6 it is laterally delimited by a spacer ring 18 which, like the metering disk 14, is clamped gas-tight by the clamping disk 15 is. The spacer ring 18 consists of a plastic material of high rigidity, compressive strength, heat resistance and preferably low thermal conductivity. Components made of polyimide, for example a type manufactured by Du Pont under the brand name “Kapton ^R ”, are particularly suitable for this. This material has the particular advantage that it has approximately the same thermal expansion as brass, so that when the valve body 2 and the clamping disk 15 are made of automatic brass, no thermal stresses interfere with the function of the device according to the invention. The spacer ring 18 can simply be punched out of commercially available foils, which enables very cheap production and allows the diameter of the metering space to be changed comfortably. The plastic material of the spacer ring 18 also promotes the sealing of the clamping surface and reduces the risk of unintentional squeezing of the metering disc 14 at the edge of the metering space 16 during assembly.

The embodiments according to FIGS. 6 and 7 correspond essentially to those according to FIG. 5, but an intermediate layer 18 '(FIG. 6) is arranged between the metering disc 14 and the bottom of the recess 12, the distance between the two position 18 'formed bottom of the metering chamber 16 has the structure. The intermediate system 18 'is preferably made of the same plastic material as the spacer ring 18 and is structured on its side facing the metering disc.

In the embodiment according to FIG. 7, the recess 16 is formed in a body 18 ″, which at the same time has the function of the spacer ring 18 from FIG. 5 and the intermediate layer 18 ′ from FIG. 6.

Finally, there is the possibility of forming the structure 22 in any combination of the shapes of the elevations and depressions. The manufacturing costs of the device according to the invention are significantly reduced by the fact that no voluminous components are used which cause high material costs. The costs for the mechanical processing of the components are also low, since no large quantities of material have to be removed or no machining with high requirements is to be carried out in places that are difficult to access, for example in deep blind holes.

Since the required small parts are all arranged in very shallow recesses, their installation is also easy and can be managed with relatively simple devices. This makes z. B. the pre-assembly of the membrane by means of ultrasonic welding, as described in FR-PS-2313638.

The small dimensions of the components also prevent the occurrence of larger thermal expansions or thermal stresses, which impair the thermal stability of the flame height. This effect can be further improved by selecting a suitable material, which ensures the same thermal expansion coefficient for all rigid components. The arrangement of thermally insulating components, such as the spacer ring 18, ensures a further improvement in the thermal stability.

• Nach dem losen Einsetzen der Dosierscheibe 14 und der Klemmscheibe 15 in die Vertiefung 12 des Ventilkörpers 2 wird ein Meßrohr 30 (Fig. 8) durch dessen Inneres ein Gas, z. B. Luft, unter genauer Druck- und Temperatur-kontrolle geleitet werden kann, gegen die Klemmscheibe mit etwa 200 N gedrückt, wobei die Peripherie der Dosierscheibe im Bereich der Ringfläche 13 komprimiert und gasundurchlässig wird, wodurch der Gasdurchfluß nunmehr dem hydraulischen Durchmesser des Dosierraumes 16 entspricht. Dabei liegt vorzugsweise der Ventilsitz 10 auf einem Auflagerohr 31 auf, welches über ein Verbindungsrohr 32 mit einem Durchflußmengensensor 33 verbunden ist. Die durch den Sensor erfaßten Meßwerte werden von einem Rechner aufbereitet, der einen Elektroorientierungsmechanismus 35 der Montiermaschine steuert. Die Messung wird bei einer Temperatur von 25 °C durchgeführt, wodurch der bereits geschilderte Abblendeffekt eines Teils der Poren noch nicht wirksam wurde. Konzentrisch um das Meßrohr 30 ist ein axial bewegbares Bördelwerkzeug 36, dessen axiale Bewegung durch den Mechanismus ausgelöst werden kann, angeordnet, welches den Rand 2a des Ventilkörpers 2 während der Messung noch nicht beaufschlagt. Mit Hilfe des sehr rasch reagierenden Durchflußmengensensors 33 wird in weniger als 0,2 Sekunden gemessen, welche Gasmenge die Dosierscheibe 14 durchströmt und dadurch ein genauer Rückschluß auf die Flammenhöhe ermöglicht. Die Messung wird durch den Rechner überwacht, der die Abweichungen vom Sollwert verarbeitet und entscheidet, ob bei Teilen, die angenommen werden, die Bördelung vorgenommen wird, oder ob auf einer nachfolgenden Arbeitsstation die Dosierscheibe und die Klemmscheibe ausgeworfen werden, und das wertvollere Ventilkörperteil wieder mit einer neuen Dosierscheibe bestückt zur Prüfstation gelangt. Die ausgeworfenen Klemmscheiben werden gesammelt, und können auch wieder verwendet werden, während, die Dosierscheiben mit zu großem oder zu kleinem Gasdurchlaß unverwendbar sind. Es ist wesentlich, daß vom Augenblick der Beaufschlagung der Dosierscheibenperipherie durch die unter dem Druck des Meßrohres 30 stehende Klemmscheibe 15 bis zur Fertigstellung der Bördelung des Randes 2a der Beaufschlagungsdruck nicht verringert wird, da sonst das Material der Dosierscheibe auf Grund der einachsigen Verstreckung seine ursprüngliche, z. B. kreisrunde Form verliert, und ein unbestimmbarer Teil der Dosierscheibenperipherie nach Verlust seiner Porosität durch Schrumpfen über den Dosierraumquerschnitt zu liegen kommen würde, wodurch die Gasmenge während und nach der Messung nicht übereinstimmen wü rde.

The production scatter usually occurring, which can cause considerable differences in the flame height within a production series, can be significantly improved in a rational manner with the device according to the invention. The simplicity of the required components enables high quality consistency. The arrangement of all small parts in easily accessible, shallow recesses also considerably reduces the likelihood of assembly errors. However, it also enables the gas permeability of the metering disc 14 to be checked in an easy manner and a selection based on the scatterings found. This can be done in the following ways, for example:

• After the loose insertion of the metering disc 14 and the clamping disc 15 into the recess 12 of the valve body 2, a measuring tube 30 (FIG. 8) through the inside of which is a gas, e.g. B. air, can be passed under precise pressure and temperature control, pressed against the clamping disc with about 200 N, the periphery of the metering disc in the area of the annular surface 13 is compressed and impermeable to gas, whereby the gas flow now the hydraulic diameter of the metering chamber 16th corresponds. The valve seat 10 preferably rests on a support tube 31, which is connected to a flow rate sensor 33 via a connecting tube 32. The measured values detected by the sensor are processed by a computer which controls an electrical orientation mechanism 35 of the assembly machine. The measurement is carried out at a temperature of 25 ° C., as a result of which the above-described dimming effect of part of the pores has not yet become effective. An axially movable flanging tool 36, the axial movement of which can be triggered by the mechanism, is arranged concentrically around the measuring tube 30 and does not yet act on the edge 2a of the valve body 2 during the measurement. With the aid of the very quickly reacting flow rate sensor 33, the amount of gas flowing through the metering disc 14 is measured in less than 0.2 seconds and thereby enables an exact conclusion to be drawn about the flame height. The measurement is monitored by the computer, which processes the deviations from the target value and decides whether the flared part is to be accepted for parts that are accepted or whether the metering disc and the clamping disc are ejected at a subsequent work station, and the more valuable valve body part equipped with a new metering disc arrives at the test station. The ejected clamping disks are collected and can also be used again, while the metering disks with too large or too small a gas passage are unusable. It is essential that from the moment the metering disk periphery is acted upon by the clamping disk 15, which is under pressure from the measuring tube 30, until the completion of the flanging of the edge 2a, the application pressure is not reduced, since otherwise the material of the metering disk, due to the uniaxial stretching, will restore its original, e.g. B. loses circular shape, and an indeterminable part of the metering disk periphery would come to lie after loss of its porosity by shrinking over the metering space cross-section, whereby the amount of gas would not match during and after the measurement.

In previously known embodiments, measures for controlling flow scattering are considerably more complex, and unsuitable parts cannot be separated from usable parts by the processing and assembly that took place before they were determined to be unusable.

Another advantage of the device according to the invention relates to the change in the originally set flame characteristic as a result of aging, which often occurs even without use. The use of a microporous, uniaxially stretched polypropy Len film, preferably made of Celgard ^R 2500 as a material for the metering disc 14 without the use of a fiber layer or the need for a wick, brings a very high aging resistance of the device according to the invention in relation to the constancy of the flame characteristic.

The uniaxially stretched polypropylene film is deformable in the undrawn direction, which could inadvertently affect the flow rate. It is therefore advisable to make the diameter of the valve bore 11 very small (for example 0.35 to 0.5 mm) so that the metering disc cannot be pressed in by the gas pressure.

As already mentioned, a preferred embodiment of the device according to the invention uses neither a dip tube nor a wick for transporting the liquid gas to the membrane, but rather ensures a space filled with gas vapor between the liquid gas level and the underside of the valve body, the pressure body used for clamping the metering disk preferably being used as Thin clamping disc is designed to keep the volume of the gas passage opening adjoining the metering disc on the tank side small, so that the residual liquid gas retained by the surface forces runs off immediately when the lighter is brought from an undefined, for example lying transport position to ignite into an upright position.

In the production of lighters such. B. not refillable pocket lighters, the amount of liquid gas must be limited to about 80% of the volume of the fuel tank, the ambient temperature during the filling process is about 20 ° to 25 ° C. This limitation is necessary for safety reasons, since the liquid fuel in later storage or when using the lighters at much higher temperatures, such as. B. 60 ° C, could cause an explosive bursting of the container.

The fact that about 20% of the capacity of the container must be taken up by the gaseous phase of the fuel is used in the lighters of the preferred embodiment to ensure that the metering disc and the components used to clamp it do not when the lighter is handled properly can come into contact with the liquid level of the fuel.

Claims (11)

1. Lighter, in particular cigarette lighter operated by liquid gas, which comprises a valve at the outlet of a valve bore (11), which valve can be closed and is connected to a burner head (4), a fuel reservoir (1) and a non-adjustable regulating device for the height of the flame located between the fuel reservoir (1) and valve bore (11), which device is provided with a metering disc (14) of porous material which is permeable to the fuel, which on its side facing the fuel reservoir (1) is pressed by means of a component (15) comprising an opening (17) for the fuel, in its edge region in a tight manner against an annular, preferably circular surface (13), which surrounds a recess, characterised in that the recess with the metering disc (14) forms a metering chamber (16), which is connected exclusively by means of the valve bore (11) to the burner head (4) and the end face (2') of the recess is provided completely or partially with a structure comprising recesses (21) maintaining a permanent connection between the metering chamber (16) and valve bore (J1) and possibly projections, bearing against which, when the valve is open, is the metering disc (14) of microporous film comprising microscopically small individual pores, closing off more and more pores with an increasing pressure difference, which is temperature-dependent.

2. Lighter according to Claim 1, characterised in that in the case of an end face (2') provided only partly with a structure, as a result of the position of the unstructured surface areas (stopping-down surfaces 23) the metering disc (14) first of all adapts itself to the latter.

3. Lighter according to Claim 1, characterised in that the depth of the metering chamber (16) amounts to two to eight times, preferably three to four times the thickness of the metering disc 14.

4. Lighter according to Claim 1, 2 or 3, characterised in that the structure contains channels (21) extending radially from the valve bore (11).

5. Lighter according to Claim 4, characterised in that the channels are grooves (21) with a wedge-shaped cross section. which then comprise mounds (22) at their side edges, in which case the depth of the grooves, with respect to the surface level of the stopping-down surfaces (23), . . amounts to many times, preferably five to twelve times the height by which the mounds project above this surface level.

6. Lighter according to Claim 4 or 5, characterised in that at least two, preferably between four and eight channels or grooves (21) are provided.

7. Lighter according to one of Claims 1 to 6, characterised in that the metering chamber (16) is located in an annular spacer disc (18).

8. Lighter according to one of Claims 1 to 6, characterised in that the end face (2') of the recess is formed by a washer (18').

9. Lighter according to one of Claims 1 to 8, characterised in that the pores of the metering disc (14) are constructed in the form of slots and preferably have a cross section which amounts to 0.04 x 0.4 wm.

10. Method for the manufacture of a lighter according to. Claim 4, 5 or 6, characterised in that the channels (21) of the structure of the end face (2') are embossed by means of an embossing tool, which comprises at least one cutting edge constructed in the shape of a wedge, in which case the embossing tool is rotated by a defined angle about its longitudinal axis between the individual embossing processes.

11. Method for the manufacture of a lighter according to one of Claims 1 to 9, characterised in that after loosely inserting the metering disc (14) and the component (15) serving as the clamping disc in a recess (12) of a valve body (2), a measuring tube, through the inside of which a gas, for example air is supplied with exact control of the pressure and temperature, is pressed against the clamping disc (15) and the metering disc (14) is pressed in a tight manner at its edge against the annular surface (13), in which case the rate of flow is monitored by means of a connected sensor and after evaluation by a computer, either the edge of the reinforcement is flanged over the clamping disc, due to which the metering disc and the clamping disc are fixed in their position corresponding to the measuring operation, or the metering disc and the clamping disc are ejected.

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