EP0435393A1

EP0435393A1 - Lamp/reflector unit

Info

Publication number: EP0435393A1
Application number: EP90203383A
Authority: EP
Inventors: Marcus Bernardus Damman; Winand Hendrik Anna Maria Friederichs
Original assignee: Philips Gloeilampenfabrieken NV; Koninklijke Philips Electronics NV
Current assignee: Koninklijke Philips NV
Priority date: 1989-12-27
Filing date: 1990-12-18
Publication date: 1991-07-03
Also published as: HUT56204A; CN1052972A; JPH04121945A

Abstract

The lamp/reflector unit comprises an electric lamp (1) having a seal (3) which is secured to a transverse wall (13) in the neck-shaped portion (12) of a reflector body (10) by means of a retaining member (20). The retaining member (20) comprises tags (22) and tongues (23) which bear on surfaces (14 and 15, respectively) of the transverse wall, the tongues (23) projecting through a rectangular opening (16) in this wall (13). During mounting, the tongues (23) are passed through this opening (16), while being directed towards the narrow edges (17) thereof, after which the retaining member (2) is rotated through 90° and the seal (3) is inserted in the opening (6) in order to fix the retaining member (20).

Description

The invention relates to a lamp/reflector unit comprising

an electric lamp provided with
- . a translucent lamp vessel having an axis and a seal whose cross-section cross to said axis is substantially rectangular,
- . an electric element in the lamp vessel,
- . current supply conductors extending from the electric element through the seal to the exterior,
a reflector body having a concave reflecting portion and a neck-shaped portion, the latter portion having a transverse wall with a first and a second surface, the current supply conductors extending through an opening in said wall,
a metal retaining member which is cementlessly connected to the seal of the lamp vessel and is secured in the neck-shaped portion of the reflector body.

Such a unit is known from US 4,829,210.
In the known unit the retaining member is dish-shaped and provided with an upstanding edge which is subdivided into tongues. These tongues bear with spring pressure on the inside of the neck-shaped portion of the reflector body.
A disadvantage of the known unit is that the retaining member may be positioned deeply or less deeply in the neck-shaped portion, so that the position the light source will take up inside the reflector body is uncertain.
Another disadvantage is that the reflecting surface of the reflector body can receive damage when the retaining member is put into position, chafing along said surface.
A further disadvantage is that the reflector body has an individual opening in the transverse wall for each of the current supply conductors, through which these conductors have to be threaded.
The known unit is closed with a glass disc and carries a lamp cap at the neck-shaped portion.
US 4,219,870 discloses a unit in which the current supply conductors emerge from a neck-shaped portion of a reflector body in the form of contact pins. The seal of the lamp vessel is secured with, for example, cement in a metal box, which box is inserted in the neck-shaped portion up to a stop and is fixed by means of a separate, latch-type member which is applied from the outside.
A similar unit is disclosed in US 4,376,967, in which again a metal box is secured around the seal with cement and in which this box comprises a hinging spring, which is pivoted and fastened after the lamp and reflector body have been joined together.
US 4,403,276 discloses a similar unit in which again a metal box is secured around the lamp vessel with cement and, after assembly of lamp and reflector body, springs at the metal box spring outwards in order to fix the lamp in the reflector body. In this unit as well as in the two preceding units the lamp is exchangeably mounted in the reflector body.
For exchangeability, however, it is necessary that the reflector body is open, i.e. not closed with a glass disc. This, however, may be hazardous from a safety point of view. There is in fact a risk of explosion at the end of the rated lamp life in the case of lamps operated at mains voltage. A glass disc then can catch the fragments. Furthermore, open units may present a fire hazard when used at a short distance from flammable materials.
The invention has for its purpose to provide a unit of the kind described in the opening paragraph which, among other characteristics, has a construction which is simple, easy to manufacture, and reliable.
According to the invention, this object is achieved in that

the opening in the transverse wall is substantially rectangular with narrow and wide edges,
the retaining member comprises a rectangular tubular portion which encloses the seal with clamping fit, and which comprises outwardly projecting tags which bear on a first surface of the transverse wall, and tongues which extend through the opening in the transverse wall and bear with an outwardly extending end portion on the second surface of the transverse wall, along the wide edges of the opening therein,
the opening in the transverse wall is so dimensioned that the tongues at the tubular portion can pass through the opening while being directed to its narrow edges during assembly of the unit.

Since the retaining member cooperates with the transverse wall, this member gets a pre-determined position inside the reflector body. This results in an accurately determined position of the electric lamp in the reflector body.
The retaining member can be easily applied in that it is directed with its tongues towards the narrow edges of the opening in the transverse wall and passed through this opening, upon which it is rotated, so that the tongues will grip around the transverse wall along the wide edges of this opening.
In a favourable embodiment, means are present which fix the retaining member.
These means may consist of, for example, a relief on the second surface of the transverse wall, so that an elevation is present at either side of a tongue, thus hampering rotation of the retaining member.
In a very favourable embodiment the electric lamp itself ensures the fixation of the retaining member. In this embodiment the seal of the lamp vessel projects into the opening of the transverse wall. This embodiment can be realised in that first the retaining member is mounted in the reflector body and then the electric lamp is inserted in the retaining member, the seal extending into the opening. Alternatively, it is possible to insert the electric lamp some way into the retaining member, to mount this member in the reflector body, and then to slide the lamp further until its seal projects into the opening.
This embodiment can have the further modification that the tongues press against the seal of the lamp vessel. The tongues may have such a position that they are directed towards one another before the lamp is put in its final position. When the lamp is slid into its final position, the seal presses the tongues apart. They are then pressed against the second surface of the transverse wall, so that a very rigid coupling is obtained.
In a variant of this embodiment, the seal extends through the opening beyond the tongues of the retaining member. This embodiment promotes the electrical safety of the lamp, since the seal forms an electrical insulation around the current supply conductors, thus ensuring that none of these conductors makes contact with the retaining member.
It is favourable for a proper coupling between the retaining member and the electric lamp if the tubular portion has tags which are bent inwards about lines which lie substantially in axial direction and which bear with clamping fit against said seal.
An indetachable connection between the retaining member and the lamp vessel is obtained if the retaining member has a tongue which faces away from the electric element, extends in axial direction, and bears against an elevation on the seal.
At an axial distance from the outwardly extending tags, the retaining member may be provided with a collar extending towards the neck-shaped portion, which can support the lamp in case of shocks or vibrations.
The electric element of the unit may be an incandescent body, for example of tungsten, e.g. in a gas containing halogen. The incandescent body may be arranged in the shape of an M. A relatively long incandescent body thus has a spatial arrangement of small dimensions, which is favourable for obtaining a light beam of high intensity. Alternatively, the electric element may be a pair of electrodes in an ionizable medium.
The reflector body may be closed with a glass disc, which may or may not be flat, or with a lens, and may be provided with a lamp cap. It may be desirable to position the transverse wall between the ends of the neck-shaped portion. Given a certain reflector body for embodiments of the unit according to the invention, a unit of smaller length can be obtained in this way.
Embodiments of the lamp according to the invention are shown in the drawing, in which

Fig. 1 shows a lamp/reflector unit, partly cut away, in side elevation,
Fig. 2 shows the reflector body in cross-section taken on II-II in Fig. 1,
Fig. 3 shows an axial section of the reflector body of Fig. 1 with the lamp and the retaining member during an assembly stage,
Fig. 4 shows the unit of Fig. 3 after a next assembly stage.

In Fig. 1, the lamp/reflector unit comprises an electric lamp 1 provided with a translucent lamp vessel 2 made of, for example, hard glass or glass having an SiO₂ content of at least 95% by weight, for example quartz glass, with an axis 4 and a seal 3 which is substantially rectangular in a cross-section transverse to said axis. An electric element 5, a tungsten incandescent body arranged in the shape of an M, is present in the lamp vessel 2. Current supply conductors 6 extend from the electric element 5 through the seal 3 to the exterior.
A reflector body 10 has a concave reflecting portion 11, which may be faceted, and a neck-shaped portion 12, which has a transverse wall 13 with a first 14 and a second surface 15. The current supply conductors extend through an opening 16 (Fig. 2) in this wall.
A metal retaining member 20 is connected cementlessly to the seal 3 of the lamp vessel 2 and secured in the neck-shaped portion 12 of the reflector body 10. In the Figure, the reflector body 10 is closed with a lens or glass disc 7 and carries a lamp cap 8 at the neck-shaped portion 12.
The opening 16 (see Fig. 2) in the transverse wall 13 is substantially rectangular with narrow 17 and wide edges 18.
The retaining member 20 has a rectangular tubular portion 21 (see also Fig. 3) which encloses the seal 3 with clamping fit. The tubular portion 21 comprises outwardly extending tags 22, which bear on the first surface 14 of the transverse wall 13, and tongues 23, which project through the opening 16 in the transverse wall 13 and bear on the second surface 15 of the transverse wall 13 with an outwardly extending end portion 24, along the wide edges 18 of the opening 16 therein. The opening 16 in the transverse wall 13 (see Fig. 3) is so dimensioned that the tongues 23 at the tubular portion 21 can pass through the opening 16 while being directed towards its narrow edges 17 during assembly of the unit.
After the lamp 1, in Fig. 3 with the retaining member 20 on its seal 3, has been applied in the reflector body, the lamp with the retaining member can be rotated through 90° about its axis 4. The tongues 23 will then bear with their end portions 24 on the second surface 15 of the transverse wall 13 along the wide edges 18 thereof (Fig. 4).
The unit shown comprises means which fix the retaining member 20 in the neck-shaped portion 12 of the reflector body. In the embodiment shown, these means are formed by the seal 3 of the lamp vessel 2. After the rotation from the position of Fig. 3 into the position of Fig. 4, the lamp vessel 2 is slid more deeply into the retaining member 20, so that the lamp seal 3 projects into the opening 16 in the transverse wall 13. It is thus impossible for the lamp 1 and the retaining member 20 to rotate anymore.
In Fig. 4, the seal 3 projects through the opening 16 beyond the tongues 23 of the retaining member 20, so that contact between the said member and the current supply conductors 6, which is still possible in Fig. 3, need no longer be feared.
The tongues 23 are still directed towards one another in Fig. 3. In Fig. 4, the seal 3 has pressed them apart. The tongues 23 now press both against the seal 3 and, as a consequence, against the second surface 15 of the transverse wall 13, so that a very rigid coupling is obtained.
In Fig. 4, the tubular portion 21 has lines 25 running in axial direction, about which lines tags 26 are bent inwards and bear with clamping fit on the seal 3, thus holding the lamp 1. The lamp is fixed in the retaining member and is thus indetachably connected to the reflector body by means of an axially extending tongue 27 which faces away from the electric element and which has moved over the elevation 9 on the seal 3 during assembly and now rests against it. The lamp cannot be pulled from the retaining member anymore, and the retaining member cannot be rotated in the reflector body anymore as a consequence.
A collar 28 at an axial distance from the outwardly extending tags 22 supports the lamp 1 in radial direction.
The transverse wall 13 is present between the ends of the neck-shaped portion 12.
The lamp has a construction which is simple, easy to realise, and reliable.

Claims

A lamp/reflector unit comprising
- an electric lamp (1) provided with
. a translucent lamp vessel (2) having an axis (4) and a seal (3) whose cross-section at right angles to said axis is substantially rectangular,

. an electric element (5) in the lamp vessel,

. current supply conductors (6) extending from the electric element through the seal to the exterior,

- a reflector body (10) having a concave reflecting portion (11) and a neck-shaped portion (12), the latter portion having a transverse wall (13) with a first (14) and a second surface (15), the current supply conductors extending through an opening (16) in said wall,

- a metal retaining member (20) which is connected cementlessly to the seal (3) of the lamp vessel (2) and is secured in the neck-shaped portion (12) of the reflector body (10),
characterized in that

- the opening (16) in the transverse (13) wall is substantially rectangular with narrow (17) and wide edges (18),

- the retaining member (20) comprises a rectangular tubular portion (21) which encloses the seal with clamping fit, and which comprises outwardly projecting tags (22) which bear on a first surface (14) of the transverse wall (13), and tongues (23) which extend through the opening (16) in the transverse wall (13) and bear on the second surface (15) of the transverse wall (13) with an outwardly extending end portion (24), along the wide edges (18) of the opening (16) therein,

- the opening (16) in the transverse wall (13) is so dimensioned that the tongues (23) at the tubular portion (21) can pass through the opening (16) while being directed to its narrow edges (17) during assembly of the unit.
A lamp/reflector unit as claimed in Claim 1, characterized in that means are present which fix the retaining member (20) in the neck-shaped portion (12) of the reflector body (10).
A lamp/reflector unit as claimed in Claim 2,
characterized in that the seal (3) of the electric lamp (1) projects into the opening (16) in the transverse wall (13).
A lamp/reflector unit as claimed in Claim 3,
characterized in that the seal (3) projects through the opening (16) beyond the tongues (23) of the retaining member (20).
A lamp/reflector unit as claimed in Claim 3 or 4,
characterized in that the tongues (23) press against the seal (3).
A lamp/reflector unit as claimed in Claim 1 or 3,
characterized in that the tubular portion (21) of the retaining member (20) has tags (26) which are bent inwards about lines (25) extending substantially in axial direction and which bear with clamping fit on the seal (3).
A lamp/reflector unit as cla med in Claim 1, 3 or 7,
characterized in that the tubular portion (21) of the retaining member (20) has a tongue (27) which faces away from the electric element (5), extends in axial direction, and rests against an elevation (9) on the seal (3).
A lamp/reflector unit as claimed in Claim 1, 3, 6 or 7,
characterized in that the retaining member (20) is provided with a collar (28) extending towards the neck-shaped portion (12) at an axial distance from the outwardly extending tags (22).
A lamp/reflector unit as claimed in Claim 3,
characterized in that the transverse wall (13) is present between the ends of the neck-shaped portion (12).