Electric lamp

Abstract: The electric lamp has a lamp vessel (1) provided with a seal (2), and a metal sleeve (10) in a first end (11) of which said seal (2) is secured. In a second end (12) of the sleeve (10) an insulator body (20) through which a contact member (30) extends is rigidly secured. To that end the sleeve (10) has a constriction (14) cooperating with the insulator body (20) at a second end face (26) thereof, and a inward projection (13) into a recess (27) in a side face (21) of the insulator body (20). The recess (27) extends to a first end face (25) of the insulator body (20). The lamp is of an easily producible construction.

Description: The invention relates to an electric lamp comprising: a lamp vessel which is sealed in a gastight manner and in which an electric element is accommodated, which element is connected to first and second current conductors which issue to the exterior through a seal of the lamp vessel; a substantially rectangular metal sleeve which is fixed with a first end portion around the said seal and which is electrically connected to the first current conductor; an insulator body provided with side faces and first and second end faces fixed in a second end portion of the sleeve; a contact tongue fixed in the insulator body, which tongue runs from outside the sleeve via the end faces through the insulator body and is connected to the second current conductor inside the sleeve; the insulator body having a recess in a side face in which an inward projection of the sleeve is accommodated. Such an electric lamp is known from GB 2 093 632 A and can be used as a vehicle headlamp. The lamp may be constructed, for example, as an H-1 lamp and have an incandescent body arranged in the direction of the sleeve inside the lamp vessel in a halogen-containing gas. The insulator body of the known lamp has a hole in a side face between the end faces, which hole runs on to the opposing side face and into which the sleeve enters with an inward projection so as to fix the insulator body in the sleeve. Since the formation of such a hole necessitates a more expensive, multiple mould for the manufacture of the insulator body, it is more attractive in the case of an insulator body made of synthetic resin to provide the hole therein through drilling after the manufacture of the body. The use of synthetic resin, however, involves a risk, i.e. when the lamp is used in an optical system, for example a reflector, volatile components originating from the resin may be deposited in that system and pollute it. This is why a ceramic insulator body is preferred. A disadvantage of the ceramic insulator body of the known lamp is that a multiple mould is necessary for manufacturing the insulator body. This is because it is not possible to provide a hole in a formed ceramic body in an industrially attractive manner afterwards. It is an object of the invention to provide an electric lamp of the kind mentioned in the opening paragraph which has a construction that is easy to manufacture. In particular, it is an object to provide such an electric lamp which has an insulator body which is easier to manufacture. According to the invention, this object is achieved in that the recess in the insulator body extends to in the first end face and the sleeve has a constriction which cooperates with the insulator body at the second end face, the inward projection and the constriction keeping the insulator body securely fixed in the sleeve. Since the recess in the lamp according to the invention extends from the first end face, the insulator body can be manufactured in a simple, two-part mould of which the mould part forming the first end face also forms the recess. The continuation of the recess into the first end face, however, means that the inward projection of the sleeve forms a stop for the insulator body in one direction only. Therefore, a constriction is present in the sleeve which cooperates with the insulator body near the second end face in order to block this body in the opposite direction. The recess may extend away from the first end face only so far that the inward projection lies at the end of the sleeve. In a favourable embodiment, the recess is a hole in the insulator body. The recess then continues up to the contact tongue. In an alternative embodiment, the insulator body has a corresponding recess in each of two opposing side faces. In a modification of this embodiment, the insulator body has a recess which runs as a hole from one side face into an opposing side face. The sleeve may then be made to project into each of these opposing side faces. A hole in the insulator body has the advantage over a shallow recess that the tools with which the inward projection is made can perform a larger stroke during this operation, so that the wall of the sleeve during making of the projection is broken through and little elastic deformation of the sleeve, and thus a very secure coupling are obtained. It is favourable to give the contact tongue at the area of the inward projection a hole which is wider than this projection, for example, wider than the recess in the insulator body. This hole may be, for example, semi-circular. This hole also increases the said stroke of the deforming tool and ensures that the sleeve with the projection does not touch the contact tongue. The constriction of the sleeve may be realised in various ways, for example, by means of a tag bent inwards from the sleeve. Convenient, however, is an indentation, or several indentations. In a favourable embodiment, the insulator body has a second recess in a side face near the second end face, with which recess the constriction cooperates. A sufficient spacing between the contact tongue and the constriction is then ensured. The first end face of the insulator body may lie inside the sleeve, but it is favourable if the second end face is situated there. The sleeve may then be provided with the constriction beforehand and the inward projection may be provided for fixation after the sleeve and the insulator body have been joined together. The contact tongue may be fixed in the insulator body in various ways, for example, by flattening the contact tongue in a known manner. An embodiment of the electric lamp according to the invention is shown in the drawing, in which Fig. 1 shows a lamp in side elevation; Fig. 2 shows a modification of the sleeve of Fig. 1 in side elevation; and Fig. 3 shows the insulator body with the contact tongue of Fig. 1 in side elevation. In Fig. 1, the electric lamp has a lamp vessel 1 which is sealed in a gastight manner and in which an electric element 3 is accommodated, in the Figure an incandescent body, for example, in a halogen-containing gas, which element is connected to first and second current conductors 4, 5 which issue to the exterior through a seal 2 of the lamp vessel. A substantially rectangular metal sleeve 10 is fixed with a first end portion 11 around the said seal 2 and electrically connected to the first current conductor 4. An insulator body 20 provided with side faces 21-24 and first 25 and second 26 end faces is fixed in a second end portion 12 of the sleeve 10. A contact tongue 30 which is fixed in the insulator body 20 runs from outside the sleeve 10 via the end faces 25, 26 through the insulator body 20 and is connected to the second current conductor 5 inside the sleeve 10. The insulator body 20 has a recess 27 in a side face 21, into which recess the sleeve 10 enters with an inward projection 13. The recess 27 in the insulator body 20 extends to in the first end face 25, and the sleeve 10 has a constriction 14 which cooperates with the insulator body 20 near the second end face 26. The projection 13 and the constriction 14 keep the insulator body 20 securely fixed in the sleeve 10. In the Figure, the second end face 26 lies inside the sleeve 10 and the first end face 25 outside it. In an alternative embodiment, this may be geometrically reversed. In Fig. 2, portions of the sleeve corresponding to portions in Fig. 1 have the same reference numerals. The first end portion 11 has rigid, resilient tags 15 for gripping the seal of the lamp vessel. In a window 16, mutually facing tongues 17 extend between which the first current conductor 4 can be fixed by welding. Indentations 14 forming a constriction of the sleeve are present for blocking the insulator body 20 against inward shifting in the sleeve. An elongate depression 18 is present for pressing against a side face of the insulator body in order to close in the latter sideways. An electrical connection of the second current conductor 5 with the contact tongue 30 may be made in the window 16. In Fig. 3, the recess 27 is a hole in the ceramic insulator body 20. A hole 27 is present in two opposing side faces 21, 23, so the body in the Figure has a continuous hole from side face 21 to side face 23. A hole 31 is present in the contact tongue 30 at the area of the inward projection 13, which hole is wider than the recess 27 at the area of the protrusion 13. The insulator body 20 has near its second end face 26 a second recess 28 which cooperates with the constriction 14 of the sleeve 20. The inward projection 13 in Fig. 1 is round. The recess 27 in Fig. 3, however, may extend only so far away from the end face 25 that the projection 13 lies at the end of the sleeve and is as a result, for example, semicircular.

Claims: An electric lamp comprising: a lamp vessel (1) which is sealed in a gastight manner and in which an electric element (3) is accommodated, which element is connected to first (4) and second (5) current conductors which issue to the exterior through a seal (2) of the lamp vessel; a substantially rectangular metal sleeve (10) which is fixed with a first end portion (11) around the said seal (2) and which is electrically connected to the first current conductor (4); an insulator body (20) provided with side faces (21 - 24) and first (25) and second (26) end faces fixed in a second end portion (12) of the sleeve 10); a contact tongue (30) fixed in the insulator body (20), which tongue runs from outside the sleeve (10) via the end faces (25, 26) through the insulator body (20) and is connected to the second current conductor (5) inside the sleeve (10); the insulator body (20) having a recess 27) in a side face (21) in which an inward projection (13) of the sleeve (10) is accommodated, characterized in that the recess (27) in the insulator body (20) extends to in the first end face (25) and the sleeve (10) has a constriction (14) which cooperates with the insulator body (20) at the second end face (26), the inward projection (13) and the constriction (14) keeping the insulator body (20) securely fixed in the sleeve (10). An electric lamp as claimed in Claim 1, characterized in that the recess (27) is a hole in the insulator body (20). An electric lamp as claimed in Claim 1 or 2, characterized in that a recess (27) is present in two opposing side faces (21, 22). An electric lamp as claimed in Claim 2 or 3, characterized in that a hole (31) is present in the contact tongue (30) at the area of the inward projection (13), which hole is wider than the recess (27) at the area of the inward projection (13). An electric lamp as claimed in Claim 1, characterized in that the insulator body (20) has near its second end face (26) a second recess (28) which cooperates with the constriction (14) of the sleeve (20). An electric lamp as claimed in Claim 1 or 5, characterized in that the constriction (14) consists of at least one indentation. An electric lamp as claimed in Claim 1, characterized in that an elongate depression (18) is present in the sleeve (20), pressing against a side face (24) of the insulator body (20).

Inventors: KRINGS WILFRIED HEINRICH, KRINGS, WILFRIED HEINRICH
Applicants: PHILIPS ELECTRONICS NV, PHILIPS PATENTVERWALTUNG, PHILIPS ELECTRONICS N.V., PHILIPS PATENTVERWALTUNG GMBH
Application year: 1992
Main classification: H01J5
IPC codes: H01J5, H01K1