Electric lamp

Abstract: The electric lamp has a lamp vessel (1) having seals (4, 5) onto which respective bases (20, 21) are secured. Each base comprises a cylindrical insulator body (22) in a free end of which a contact member (30) is accommodated, having a contact face (31) and a protruding portion (33) which has a connection area (32) to which a current supply conductor (8) of the lamp is secured. The contact member (30) is a body made from metal foil.

Description: The invention relates to an electric lamp comprising a lamp vessel which is closed in a vacuumtight manner, in which an electric element is arranged, and which has a first and a second seal, current supply conductors connected to the electric element and issuing from the lamp vessel to the exterior through the first and second seal, respectively, lamp caps fastened to the first and second seal, respectively, and comprising a cylindrical insulator body having a centreline, in a free end of which body a contact member is accommodated which has a contact face and a protruding portion with a connection area where a relevant current supply conductor is fixed. Such an electric lamp is known from US-3 001 096. The contact members therein consist of solid nickle bodies. A disadvantage of this is that the contact members are difficult to manufacture by means of operations such as pressing and cold deformation, and that machining operations such as milling, drilling and grinding may be necessary. An electric lamp is known from CA-828 294 in which the contact member is a disc of metal plating against which the current supply conductor is fastened with solder in a butt joint. A disadvantage of this lamp is the use of solder, both because of the long process time in making the joint and because of the low heat resistance of this joint. A welded joint, however, would involve the risk of the contact face having a deformation owing to welding. The invention has for its object to provide an electric lamp of the kind described in the opening paragraph which has improved contact members. According to the invention, this object is achieved in a lamp of the kind described in the opening paragraph in that the contact member is a body formed from metal foil with a cylindrical flanged rim at the contact face, which rim supports the connection area. The lamp according to the invention has the advantage that its contact members can be shaped in a deep-drawing process and that the connection area may have various shapes. The contact members may consist of, for example, nickle, nickle-plated CrCu, or nickle-plated CuZn. In the case of nickle-plated contact members, nickle-plating may be realised before or after they have been shaped. In a favourable embodiment, the cylindrical flanged rim has one or more, for example, two tongues as the connection area(s). Such a tongue may be bent away from the cylindrical rim and extend, for example, along the contact face. A current supply conductor may then be fastened by means of, for example, a butt weld. The tongue may alternatively have an end portion as the connection area, extending along the centreline of the insulator body, e.g. of ceramic. A current supply conductor may then be fastened laterally to this end portion. Resistance welding or laser welding, for example, are suitable for this purpose. Alternatively, the conductor may be clamped or, if the lamp has a comparatively low operating temperature, soldered. It may be favourable if the current supply conductor is a U-shaped bent wire, or is obtained therefrom by separating the bend. The contact member may then be connected to the current supply conductor in two spots situated laterally next to one another. The contact member may for that purpose have two separate connection areas. In another embodiment, the contact member has a strip formed from the cylindrical flanged rim which is created by an incision transverse to the centreline and which is bent towards this centreline to form the connection area. The strip may be folded in order to form a discrete location for a current supply conductor in a fold. Two such strips may alternatively be present in lamps having a current conductor with parallel portions, one for each portion. The electric element of the lamp is of no importance for the principle of the invention. It may be an incandescent body, or a pair of electrodes, possibly in an inner envelope. This and other aspects of the lamp according to the invention are shown in the drawings. In the drawings Fig. 1 shows a lamp in side elevation; Fig. 2 shows an embodiment of a contact member in longitudinal section; Fig. 3 shows the contact member of Fig. 2 taken on the line III; Fig. 4 is a side elevation of an alternative embodiment of a contact member; Fig. 5 shows the contact member of Fig. 4 taken on the line V; Fig. 6 is a side elevation of a further embodiment; Fig. 7 shows the embodiment of Fig. 6 taken on the line VII; Figs. 8 and 9 show a modification of Figs. 6 and 7; Fig. 10 shows a next embodiment in side elevation; Fig. 11 shows the contact member of Fig. 10 taken on the line XI. In Fig. 1, the electric lamp has a lamp vessel 1 which is closed in a vacuumtight manner and in which an incandescent body 3 is positioned as the electric element. The lamp vessel 1 has a first and a second seal 4, 5 through which current supply conductors 8 are passed from the incandescent body 3 to the exterior. Lamp caps 20, 21 are fastened to the first and the second seal, respectively, for example with cement, such as lamp cement. The lamp caps 20, 21 each have a cylindrical insulator body 22, e.g. of ceramic, which has a centreline 23, in a free end of which body a contact member 30 is accommodated. This member has a contact face 31 (Figs. 2, 3) in order to effect an electrical connection with a lampholder through the open free end of the insulator body, and a protruding portion 33 with a connection area 32 to which the current supply conductor 8 is fastened. The contact member 30 is a body formed from metal foil and having as a protruding portion a cylindrical flanged rim 33 at the contact face 31 which carries the fastening area 32. The contact member 30 in Figs. 2 and 3 has a concave, spherical contact face 31. The flanged rim 33 has a tongue 34 which extends along the contact face 31 and which has an end portion 35 which runs alongside the centreline 23 and comprises the connection area 32. The end portion 35 is split and has two concave curved connection areas 32 as predetermined seats on which parallel portions 81, 82 of a current supply conductor are fastened, for example, by laser welding. In Figs. 4, 5, corresponding parts of the contact member have reference numerals which are 10 higher than those in Figs. 2, 3. The member has two tongues 44 with concave end portions 45 which face one another. A current supply conductor 8 is brought between them and, owing to a relative rotation, takes up a position between these end portions 45 where the interspacing of these end portions corresponds to the external dimension of the U-shaped current supply conductor 8. In Figs. 6, 7, the contact member 50 has a contact face 51 with a cylindrical flanged rim 53 from which a strip 56 is formed by an incision 58 transverse to the centreline 23, which strip is bent towards the centreline 23 to form the connection area 52. The strip has a bend 57 in order to form discrete connection areas 52 for current supply conductor portions 81, 82. Figs. 8, 9 show a modification with reference numerals which are 10 higher than those in Figs. 6, 7. The strip 66 has bends 67 of such a nature that a discrete connection area for a current supply conductor is created, but also for parallel portions 81, 82. In Figs. 10, 11, parts have reference numerals which are 10 higher than corresponding parts in Figs. 8, 9. The contact member 70 has two strips which comprise the connection areas 72. Their interspacing is smaller than the external dimension of the current supply conductor 81, 82. This conductor is brought between the strips 76 and rotated relatively until both parallel portions 81, 82 hit against a respective strip. They are then fixed.

Claims: An electric lamp comprising a lamp vessel (1) which is closed in a vacuumtight manner, in which an electric element (3) is arranged, and which has a first and a second seal (4, 5, respectively), current supply conductors (8) connected to the electric element (3) and issuing from the lamp vessel (1) to the exterior through the first and second seal (4, 5), respectively, lamp caps (20, 21) fastened to the first and second seal (4, 5), respectively, and comprising a cylindrical insulator body (22) having a centreline (23), in a free end of which body a contact member (30) is accommodated which has a contact face (31) and a protruding portion (33) with a connection area (32) where a relevant current supply conductor (8) is fixed, characterized in that the contact member (30) is a body formed from metal foil with a cylindrical flanged rim (33) at the contact face (31), which rim supports the connection area. An electric lamp as claimed in Claim 1, characterized in that a tongue (34) is present at the flanged rim (33), to which tongue a current supply conductor (8) is fastened. An electric lamp as claimed in Claim 2, characterized in that the tongue (34) extends along the contact face (31). An electric lamp as claimed in Claim 3, characterized in that the tongue (34) has an end portion (35) as the connection area (32) which runs alongside the centreline (23). An electric lamp as claimed in Claim 1, characterized in that a strip (56), which is bent towards the centreline (23) to serve as the connection area (52), is formed from the cylindrical flanged rim (53) by means of an incision (58) transverse to the said centreline. An electric lamp as claimed in Claim 1, 4 or 5, characterized in that the current supply conductor (8) is a wire bent into a U-shape. An electric lamp as claimed in Claim 1, 4 or 5, characterized in that the current supply conductor (8) comprises a first (81) and a second (82) parallel wire. An electric lamp as claimed in Claim 1, 4 or 5, characterized in that the current supply conductor (8) is fixed to the connection area (32, 52) with two parallel portions (81, 82). An electric lamp as claimed in Claim 1, characterized in that the contact member (70) has two connection areas (72) and that the current supply conductor (8) is fixed to respective connection areas (72) with two parallel portions (81, 82).

Inventors: HOHAUS KARL-HEINZ, MEERTENS JOSEPH ANTONIUS, VAN DULMEN HENDRIKUS ALBERTUS, HOHAUS, KARL-HEINZ, MEERTENS, JOSEPH ANTONIUS, VAN DULMEN, HENDRIKUS ALBERTUS MARIA
Applicants: PHILIPS ELECTRONICS NV, PHILIPS PATENTVERWALTUNG, PHILIPS ELECTRONICS N.V., PHILIPS PATENTVERWALTUNG GMBH
Application year: 1992
Main classification: H01J5
IPC codes: H01K1, H01J5