Incandescent Lamp With Mechanically Attached Base

The present invention relates to an incandescent lamp having a base shell mechanically secured thereto in the region of the press seal.

It is the object of the invention to provide an incandescent lamp with a base shell in the press seal region and whose mechanical base support is simpler, safer and less expensive than prior art devices, and especially which does not require adhesives or cement.

Briefly, the base shell and the lamp press are secured together by a sleevelike insert snugly matching the inner diameter of the base shell. The insert has an annular bottom. Diametrically opposite flaps formed by a diametrical cut, extend along the base shell. The end portions form in-turned wings. The wings are inwardly bent. A knob, or punch, in one of the flaps, engages a matching recess, or projection in the base shell to prevent relative rotation. The side ends of the wings resiliently abut the press seal.

FIG. 1 shows a halogen, incandescent lamp, partially in section with a mechanically secured base;

FIG. 2 shows the sleevelike insert partially in section,

FIG. 3 shows a cut through the lamp of FIG. 1 along the line A--A in top view.

An incandescent lamp 1, for instance a halogen cycle incandescent lamp, has a press seal 2. In accordance with the invention, a base shell 3 of essentially circular cross section, for instance a bayonet-type base shell is mechanically attached to and supported on the lamp by means of a sleevelike insert 4. The lead-in wires pass through the press seal 2 of lamp 1 to the exterior and terminate in the base contacts 5, 6 of the base insulator 14 as well known (FIG. 1). The sleeve-like insert 4 snugly matches the inner diameter of the base shell 3. The insert 4 is provided with an annular bottom 7. The tubular portion of the sleeve-like insert is longitudinally cut to form two part tubular portions or diametrically opposite flaps 9 which extend longitudinally of the lamp. The side ends 10 of the flaps 9 are formed as wings which are bent inwardly and include an angle .alpha. of between 30.degree. and 80.degree.. The wings 10 resiliently abut the press seal 2 of the lamp (FIGS. 2, 3). The wings 10 are shorter than the flaps 9, by being cut at the bottom as seen at 8.

In order to prevent changes in position, the insert 4 is secured by a bulge, bump or knob 11 in one of the flaps 9 and a matching recess 13 in the tubular portions, or base shell 3 which engage in interlocking manner. The insert 4 inserted in the base shell 3 extends close to the upper edge 12 of the base shell and is preferably flush with the base shell edge. The upper edges 10a of the wings 10 are partly beveled relative to the horizontal at an angle .beta. of less than about 80.degree.. The insert 4 is made of sheet brass having a thickness of from 0.2 to 0.4 mm.

Various changes and modifications may be made; for example, base 3 may be a screw base or prong cap or the like instead of the bayonet base.