GB2093632A

GB2093632A - A lamp base

Info

Publication number: GB2093632A
Application number: GB8202479A
Authority: GB
Original assignee: Patent Treuhand Gesellschaft fuer Elektrische Gluehlampen mbH
Current assignee: Osram GmbH
Priority date: 1981-02-20
Filing date: 1982-01-28
Publication date: 1982-09-02
Also published as: DE8104771U1; GB2093632B

Abstract

A lamp base comprises a ceramic insulating member 1 which has a through opening for the reception of conductive contact tongue 4, which is retained by a part 9 thereof which is upset. The top of tongue 4 is arranged to contact one lead-wire of an inserted lamp and a conductive base sleeve, which is attached to member 1, is arranged to contact the other lead wire. <IMAGE>

Description

SPECIFICATION Lamp base The present invention relates to a lamp base and more particularly to a base for a single filament halogen cycle incandescent lamp (HItype).

It is known to embed the contact tongue of the base of a single filament halogen cycle incandescent lamp (Hl-type) in the base insulation of a rapid-mould polyester compound while the base insulation is formed. Although this ensures a reliable joint, free from play between the contact tongue and the base insulation, it may happen during the manufacture that the contact tongue is oxidized because the mould component is compressed about it in the hot state. As a result, the lamp makes a poor contact. The heat generated during operation of the lamp also may cause vapour to be released from the base insulation. The vapour will be deposited on the reflector or on the front lens of a headlamp or on the lamp bulb itself so that the light emission from the headlamp is reduced.

It is known to use a material of mica and glass for the base insulation in order to prevent evaporation of the base insulation during the operation of such lamps. Like the rapid mould polyester compound, this material, too, is compresses about the contact tongue in the hot state (about 350"C). For this reason it is highly probable that the contact tongue will oxidize in the manufacture of the base with these lamps, too.

It is an object of the present invention to prevent oxidation of the contact tongue during the manufacture of the base of a single filament halogen cycle incandescent lamp (HItype) and and evaporation of the material from the base insulating during operation of the lamp. It is also an object of the present invention to provide simplified manufacture of the lamp and therefore lower manufacturing costs.

According to the present invention there is provided a lamp base comprising a base shell which is arranged to be connected in electrically conductive manner to one of two lead-in wires of a lamp inserted in the base, a ceramic base insulating member comprising a slot-like opening which extends in the direction of the axis of an inserted lamp, and a contact tongue which is arranged to be connected in electrically conductive manner to the other of said lead-in wires, the contact tongue comprising a contact lug and an integrally formed flap portion, the flap portion being passed through said slot-like opening and being upset at the part thereof where it emerges from the base insulating member.

A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings of which: Figure 1 shows a sectional view of the base insulation of the lamp base of a single filament halogen cycle incandescent lamp in accordance with the present invention; Figure 2 shows a side view of the base insulation of Fig. 1 with the contact tongue passed therethrough; Figure 3 shows on a smaller scale a side view of the completely assembled base of the single filament halogen cycle incandescent lamp; and Figure 4 shows a side view turned through 90 of the base along the line A-A of Fig. 3, partially in section.

In Fig. 1, the numeral 1 designates the substantially right parallelepipedal base insulating member of the lamp base of a single filament halogen cycle incandescent lamp (HItype) in accordance with the present invention. The base insulation or insulating member 1 consists of a ceramic which does not emit vapour and has a narrow slot-like opening 2 in the axial direction of the lamp which in its lower portion 3, however, extends over nearly the entire width of the base insulation 1. The opening 2 is provided for the reception of the contact tongue 4 (see Fig. 2). Advantageously, the narrow portions of the slot-like opening 2 is laterally offset from the middle line M of the base insulation 1 so that sufficient space is provided in the remaining, solid part of the base insulation. 1 for the base shell or sleeve 6 to be affixed (see Figs. 3 and 4).

Fig. 2 illustrates the base insulation 1 together with the contact tongue 4. The contact tongue 4 consists of a contact lug 7 and a flap 8 integrally formed on the contact lug 7.

The contact tongue 4 is inserted into the slot iike opening 2 from below until the lower portion 3 of the opening 2 is completely filled by the contact lug 7 and the narrow portion 5 of the opening 2 is filled by the flap 8. The major portion of contact lug 7 still extends from the underside of the base insulation 1, and nearly half of the flap 8 extends from the upper side of the base insulation 1. The contact tongue 4 is anchored in the base insulation 1 by the flap 8 which is upset in a narrow region 9 immediately above the base insulation 1.

The base shell 6 of the Figs. 3 and 4 corresponds largely to known base shells of single filament halogen cycle incandescent lamps (Hl-type) and therefore needs not be described in more detail. The attachment of the base shell 6 is conventional, too. The base insulation 1 has within its solid part, through which the slot-like opening 2 does not pass, a bore 10 in which the base shell 6 is anchored by a rivet 11.

1. A lamp base comprising a base shell which is arranged to be connected in electri

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Lamp base The present invention relates to a lamp base and more particularly to a base for a single filament halogen cycle incandescent lamp (HItype). It is known to embed the contact tongue of the base of a single filament halogen cycle incandescent lamp (Hl-type) in the base insulation of a rapid-mould polyester compound while the base insulation is formed. Although this ensures a reliable joint, free from play between the contact tongue and the base insulation, it may happen during the manufacture that the contact tongue is oxidized because the mould component is compressed about it in the hot state. As a result, the lamp makes a poor contact. The heat generated during operation of the lamp also may cause vapour to be released from the base insulation. The vapour will be deposited on the reflector or on the front lens of a headlamp or on the lamp bulb itself so that the light emission from the headlamp is reduced. It is known to use a material of mica and glass for the base insulation in order to prevent evaporation of the base insulation during the operation of such lamps. Like the rapid mould polyester compound, this material, too, is compresses about the contact tongue in the hot state (about 350"C). For this reason it is highly probable that the contact tongue will oxidize in the manufacture of the base with these lamps, too. It is an object of the present invention to prevent oxidation of the contact tongue during the manufacture of the base of a single filament halogen cycle incandescent lamp (HItype) and and evaporation of the material from the base insulating during operation of the lamp. It is also an object of the present invention to provide simplified manufacture of the lamp and therefore lower manufacturing costs. According to the present invention there is provided a lamp base comprising a base shell which is arranged to be connected in electrically conductive manner to one of two lead-in wires of a lamp inserted in the base, a ceramic base insulating member comprising a slot-like opening which extends in the direction of the axis of an inserted lamp, and a contact tongue which is arranged to be connected in electrically conductive manner to the other of said lead-in wires, the contact tongue comprising a contact lug and an integrally formed flap portion, the flap portion being passed through said slot-like opening and being upset at the part thereof where it emerges from the base insulating member. A preferred embodiment of the present invention will now be described, by way of example only, with reference to the accompanying drawings of which: Figure 1 shows a sectional view of the base insulation of the lamp base of a single filament halogen cycle incandescent lamp in accordance with the present invention; Figure 2 shows a side view of the base insulation of Fig. 1 with the contact tongue passed therethrough; Figure 3 shows on a smaller scale a side view of the completely assembled base of the single filament halogen cycle incandescent lamp; and Figure 4 shows a side view turned through 90 of the base along the line A-A of Fig. 3, partially in section. In Fig. 1, the numeral 1 designates the substantially right parallelepipedal base insulating member of the lamp base of a single filament halogen cycle incandescent lamp (HItype) in accordance with the present invention. The base insulation or insulating member 1 consists of a ceramic which does not emit vapour and has a narrow slot-like opening 2 in the axial direction of the lamp which in its lower portion 3, however, extends over nearly the entire width of the base insulation 1. The opening 2 is provided for the reception of the contact tongue 4 (see Fig. 2). Advantageously, the narrow portions of the slot-like opening 2 is laterally offset from the middle line M of the base insulation 1 so that sufficient space is provided in the remaining, solid part of the base insulation. 1 for the base shell or sleeve 6 to be affixed (see Figs. 3 and 4). Fig. 2 illustrates the base insulation 1 together with the contact tongue 4. The contact tongue 4 consists of a contact lug 7 and a flap 8 integrally formed on the contact lug 7. The contact tongue 4 is inserted into the slot iike opening 2 from below until the lower portion 3 of the opening 2 is completely filled by the contact lug 7 and the narrow portion 5 of the opening 2 is filled by the flap 8. The major portion of contact lug 7 still extends from the underside of the base insulation 1, and nearly half of the flap 8 extends from the upper side of the base insulation 1. The contact tongue 4 is anchored in the base insulation 1 by the flap 8 which is upset in a narrow region 9 immediately above the base insulation 1. The base shell 6 of the Figs. 3 and 4 corresponds largely to known base shells of single filament halogen cycle incandescent lamps (Hl-type) and therefore needs not be described in more detail. The attachment of the base shell 6 is conventional, too. The base insulation 1 has within its solid part, through which the slot-like opening 2 does not pass, a bore 10 in which the base shell 6 is anchored by a rivet 11. CLAIMS

1. A lamp base comprising a base shell which is arranged to be connected in electri cally conductive manner to one of two lead-in wires of a lamp inserted in the base, a ceramic base insulating member comprising a slot-like opening which extends in the direction of the axis of an inserted lamp, and a contact tongue which is arranged to be connected in electrically conductive manner to the other of said lead-in wires, the contact tongue comprising a contact lug and an integrally formed flap portion, the flap portion being passed through said slot-like opening and being upset at the part thereof where it emerges from the base insulating member.

2. A lamp base according to claim 1 wherein the base shell is of substantially rectangular cross-section and said base insulating member is a substantially right parallelepiped.

3. A lamp base substantially as herein described with reference to the accompanying drawings.

4. A single filament halogen cycle incandescent lamp having a lamp base according to any one of the preceding claims.