Piezoelectric gas igniter

Abstract: A piezoelectric gas lighter (10), with a cartridge of the one-spark strike type, is formed by two complementary elements or bodies, a back body (12) and a front body (14), provided with means for the mutual quick connection. The front body (14) extends in the upper part into an integral tubular extension (28) wherein lead (18) of the piezoelectric unit (16) passes, and in the lower part into a protruding sector (36) which forms the activation push-button and extends inside the same body, circumscribing a seat (38) which houses said cartridge. The back body (12) is provided with a rib (20) against which the back end of the piezoelectric unit (16) abuts.

Description: This invention relates to a piezoelectric gas lighter. More particularly, this invention relates to a piezoelectric gas lighter comprising a mechanism with ceramic elements which, subject to strike, generate at each activation the formation of a spark in correspondence of an end electrode. Piezoelectric cartridge devices generating sparks have been known for a long time and are commonly utilized in house kitchen for lighting kitchen gas-rings. These devices, generically defined gas lighters, are of two different types, depending on whether they adopt multi-spark or one-spark piezoelectric mechanisms. It is known that the one-spark gas lighters of prior art have some serious drawbacks, especially as concerns their complicated structure, which gives rise consequently to construction and assembly difficulties, besides affecting their cost, as in FR-A-2 072 731. In fact, said gas lighters are formed by a plurality of components mutually connected to one another. Firstly, the container where the piezoelectric unit is housed, is generally formed by two half-shells, preferably from plastic material, connected through screws. The activating push-button, connected to said piezoelectric unit, comprises in the container special strikers and a sliding seat. The mechanism provided with ceramic elements which are subject to strike during the activation of the push-button must be stably fixed to said container. A further component is constituted by a small tube, preferably from metal, where the lead coming out of the piezoelectric unit passes and extends up to the front end of said tube, in correspondence of which the end electrode forming the sparks is obtained. Also this tube must be strongly connected to the container, which is provided for this purpose with special seats with guide and centering ribs. Conventional gas lighters require also an electric connection between the mass of the mechanism and the metal tube. It is obvious that this structure involves the preparation of specific equipments for the realization and the assembly of the many components that make up the gas lighter and which involve an overall increase in the production costs. Object of this invention is to obviate the aforementioned drawback. More particularly, object of this invention is to provide a piezoelectric gas lighter of the one-spark tipe formed by a reduced number of components, whose assembly can be performed in a quick a simple way, with no need for special equipments to connect the individual components. A further object of this invention is to provide a piezoelectric gas lighter such as to ensure a high degree of resistance and reliability in the time, and besides such as to be easily and economically realizable. According to this invention, these objects are achieved by the features in the characterizing part of claim 1. The piezoelectric gas lighter of this invention comprises an envelope housing the piezoelectric one-spark strike mechanism with the related lead, which envelope is formed by two complementary elements or bodies: a first back body and a second front body, provided each with means for the quick mutual connection. The first front body extends in its upper part into an integral tubular extention wherein the lead passes, and, in its lower part, into a protruding sector, slightly spaced from said tubular extension, which develops inside said body forming a seat in which the piezoelectric mechanism is fixed. The construction and functional characteristics of the piezoelectric gas lighter of this invention will be better stressed by the following detailed description, wherein reference is made to the figures of the attached drawing, which represent a preferred embodiment of the invention, and wherein: Fig. 1 shows the schematic, partly sectioned side view of the components of the piezoelectric gas lighter of this invention; and Fig. 2 shows the schematic view of a longitudinal section of the fully assembled gas lighter of Fig. 1. Unless otherwise explained in detail, the dimensions, dimensional proportions, construction materials and so forth are well within the understanding of those skilled in the art. The first back element or body (12) has, according to a preferred embodiment, a substantially glass-shaped configuration, whose open fore-front (12') circumscribes the engagement-seat of the second complementary element or body (14). Said first body (12) is formed by a sector having a more extended wall and a diametral sector having a wall less extended that the first one. In correspondence of the sector of body (12) having the more extended wall a rib (20) is obtained which extends starting from the internal back wall, forming a longitudinally extended flange of reduced thickness. Rib (20) extends in body (12) for a length equal to about two thirds of the most extended wall of said body, which in the representation illustrated by way of example in Figs. 1 and 2 corresponds to the upper diametral sector. In the lower diametral half-part, mouth (12') of body (12) is slightly lowered. Close to said mouth (12'), along the portion of body (12) having the most extended wall, a through-opening is formed (24), having, by way of example, a rectangular shape and a limited extension. Within said opening (24) a protrusion (26) snap-fits, which the second front element or body (14) is provided with. Said second front body (14) has a round section, with an open back front (14'), with a diameter slightly shorter than the diameter of the first complementary body (12), so that it can be engaged in said first body (12). The upper half-part of the second body (14) is frontally extended into an integral tubular extension (28). The front end of said tubular extension (28) is open and a drilled end-piece (30), of which more will be said in the following, is engaged in said front end. In correspondence of the opposite back end, the tubular extension (28) is provided with a through-opening (32) having, by way of example, a rectangular shape, circumscribed on the front by a protrusion (34). The second body (14) is provided with a substantially cylindrical portion which develops from its lower fore-front, under the tubular extension (28), circumscribing a protruding sector (36), slightly spaced from the above tubular extension (28). Said sector (36) forms an extension of the second body (14) in the part under the aforementioned extension (28) and extends inside said body, forming a substantially glass-shaped integral seat (38), without back wall. The internal diameter of said glass-shaped seat (28) is slightly greater than the diameter of the piezoelectric mechanism (16) which is inserted in the same. The fore-front of sector (36), slightly spaced from extension (28) is closed by a wall (40) having preferably a round shape. Said wall (40) forms the grip-point for the movement of the piezoelectric mechanism, as will be precised later on. The glass-shaped seat (38) is preferably provided with a through-milling (38'), longitudinally extended and substantially aligned with the axis of extension (28). Said milling (38') forms the guide wherein lead (18) abuts in its stating part which develops from the piezoelectric mechanism (16). The end-piece (30), which is pressure-fitted on the fore-front of the tubular extension (28), is formed by a core from pastic material, preferably analogous to the one that forms the first body and the second body (12, 14), and is provided with an axial hole (30') for the passage of the end of lead (18). On said extension (18) o small metal tube (42) is fitted, provided on its upper end with conventional openings (44) and an end electrode (46). Said end electrode (46) facing lead (18) causes the formation of the spark as a consequence of the activation of the piezoelectric mechanism (16). In the back part of tube (42) a through-opening (38) is formed wherein protrusion (34) fits in, said protrusion being obtained before opening (32). Sector (36) is provided, in its wall that exdends in the back in the inside of body (14), with a lowering (50) which forms a striking wall for the piezoelectric mechanism (16). The latter is inserted, during the assembly stage of the gas lighter, in seat (38) of the second body (14) and rests, with its front end, agsinst said lowering (50), facing the through-opening (32) obtained on the tubular extension (28). Wire (18), coming out of the piezoelectric mechanism (16), runs along the through-milling (38') of seat (38), which extends in the front part into the aforementioned tubular extension (28), protruding from the same for a reduced length. On the free front end of lead (18) the end-piece (30) is fitted on, which is provided with hole (30'), to house said end. The end-piece (30), which is then pressure-fitted into the mouth of extension (28),is the constant centering member of lead (18). Then, on extension (28) the metal tube (42) is fitted on which abuts, with its back end portion, the metal forefront of the piezoelectric mechanism (16) facing the through-opening (32), closing the electric circuit. Tube (42) is kept in position by protrusion (34) formed on the wall of extension (28), which elastically engages in the through-opening obtained on said tube. The second front element or body (14) is then fitten in mouth (12') of the first back element or body (12); the coupling is made in a very easy and quick manner, as protrusion (26) obtained on body (14) snap-inserts into the through-opening (24) obtained on the first body (12), as the latter has a diameter slightly greater than the diameter of the second body (14). The connection of the two bodies (12, 14) causes the back end of the cartridge or the piezoelectric mechanism (16) to strike rib (20) created inside the first back body (12). The through-opening (24) is sized according to the travel of the mobile part of said cartridge (16), so that protrusion (26) of body (14) abuts in its more advanced part and allows a suufficient backwards movement of said body during the activation of the gas lighter (10). During the use, cartridge (16) is activated by the pressure exercized on the protruding sector (36) which forms the activating push-button, causing the formation of the spark between the lower end of lead (18) and the end electrode (46). The extension of the through-opening (24) allows the suitable backwards movement of body (14). When the push-button is released, cartridge (16), Which is provided with a conventional spring, goes back to its starting position, pushing forwards the front body (14) up to the point where protrusion (26) meets the front end of the through-opening (24). As can be understood from the above, the advantages achieved by the gas lighter subject matter of this invention are obvious. In fact, it has an extremely simple structure and a limited number of components whose assembly is quick and does not need specific equipments or additional connection means. The complementary back and front bodies might have different configuration and section compared with what has been described and illustrated by way of example and be connected to one another by means of several protrusions and corresponding through-openings. Besides, the front body (14) wherein the seat of the piezoelectric mechanism is formed, might be obtained fully from metal, excluding the presence of the end-piece, the metal tube fitted on the tubular extension, and the through-opening facing said piezoelectric mechanism. Alternatively, an insulating bushing might be provided between the lead of the aforementioned mechanism and the internal surface of the tubular extension on which it rests.

Claims: A piezoelectric gas lighter (10), comprising an envelope in which a piezoelectric mechanism (16) of the one-spark strike type, with related lead (18), characterized in that said envelope is formed by two complementary elements or bodies (12,14), a back body (12) and a front body (14), provided with means for their quick mutual connection, the front body (14) extending in its back part into an integral tubular extension (28) wherein lead (18) passes and, in its lower part, into a protruding sector (36), slightly spaced from said tubular extension (28) which develops within said front body (14), forming a seat (38) in which the piezoelectric mechanism (16) is housed. The piezoelectric gas lighter according to claim 1, in which the envelope formed by the two complementary elements or bodies (12, 14) forms at the same time the seat housing the piezoelectric mechanism (16), the handle, the activation push-button of said mechanism and a tubular extension (21) for a lead (18). The piezoelectric gas lighter according to claim 1 or 2, characterized in that the back body (12) has a glass-shaped configuration in which the open fore-front (14) circumscribes the engagement seat of the complementary front body (14) having a substantially cylindrical back portion with a diameter slightly shorter than the diameter or the back body (22); said back body being provided with a rib (20) which develops starting from the back internal wall (22) and forms a longitudinally extended flange of reduced thickness. The piezoelectric gas lighter according to any of the preceding claims, characterized in that the back body (12) is provided, close to mouth (12'), with a through-opening (24), and the front body (14) is provided with a protrusion (26), which fits into said through-opening (24). The piezoelectric gas lighter according to any of the preceding claims, characterized in that the extension towards the inside of the second body (14) of the protruding sector (36) forms a substantially glass-shaped seat (38), without back wall and provided with a through-milling (38'), longitudinally extended and aligned with the axis of extension (28); a lowering (50) forming a striking wall for the piezoelectric mechanism (16) being obtained on said sector (36). The piezoelectric gas lighter according to any of the preceding claims, characterized in that the tubular extension (28) has, in correspondence of the back end, a through-opening (32) which is faced by or from which protrudes the mass element of the piezoelectric mechanism (16). The piezoelectric gas lighter according to any of the preceding claims, characterized in that a small metal tube (42) is fitted on the tubular extension (21); said tube being provided at the front end with one or several openings (44) and an end electrode (46), and at the back with a through-opening (48) wherein protrusion (34) abuts, formed before opening (32) of extension (28). The piezoelectric gas lighter according to any of the preceding claims 3-7, characterized in that the back body with the internal rib (20) and the front body (14) with the integral tubular extension (28), protruding sector (36) and internal seat (38) for the piezoelectric mechanism (16) are made from plastic material. The piezoelectric gas lighter according to any of the preceding claims from 3 to 7, characterized in that the back body with the internal rib (20) and the front body (14) with the integral tubular extension (28), protruding sector (36) and internal seat (38) for the piezoelectric mechanism (16) are made from metal.

Inventors: BONOMETTI SERGIO DR, BONOMETTI, SERGIO, DR.
Applicants: ELB S R L, ELB S.R.L.
Application year: 1996
Main classification: F23Q3
IPC codes: F23Q3