Patent Grant
7321189
1. Field of the Invention
The invention relates to electric lamps and particularly to electric lamps with press-seals. More particularly the invention is concerned with press-seals to be fitted in wedge type sockets.
2. Description of the Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Prior art wedge lamps have a relatively small press-seal thickness. The leads are also thin and are easily bent. The combination allows the lead wires to be bent back over the press-seal. The total thickness is not great and a wedge type sockets have been developed to receive these lamps with bent over lead wires. Larger lamps have a thicker press-seal dimension and have heavier wires. The lead wires are not easily bent over the press-seal, and even if they could be, the combined thickness is too large to be received in the existing wedge type sockets. As a result, brighter and more efficient tungsten halogen type lamps have not been used in standard wedge type sockets. There is then a need for a larger lamp or tungsten halogen lamp that can be fitted to existing wedge type sockets.
A larger, more efficient incandescent lamp may be adapted to a wedge type socket by restructuring the lead connections. The lamp includes a light transmissive envelope defining an enclosed volume; and has a press-sealed end. A filament type light source is positioned in the defined volume. A first electrical lead passes through the press-sealed end, and has a first end electrically coupled to the filament and has a second end extending along a first axis away from the press-seal, and is exposed on the lamp exterior for electrical connection. A second electrical lead passes through the press-sealed end, having a first end electrically coupled to the filament and having a second end extending along a second axis away from the press-seal, and is exposed on the lamp exterior for electrical connection. The second end of the first lead includes a first contact face and a second contact face. The first contact face and the second contact face are offset one from the other, and each contact face is approximately parallel to the other and to the first lead axis. The second end of the second lead may include a similar first contact face and a similar second contact face.
The preferred lamp 10 is an incandescent lamp, such as a tungsten halogen lamp capsule, with a light transmissive envelope 12 defining an enclosed volume 14. The envelope 12 may have any convenient shape, although the Applicant prefers an axially aligned tube. The envelope 12 includes a press-sealed end 16.
Positioned in the defined volume 14 is a filament that serves as the preferred type light source 18. It is understood that any other convenient light could be used, such as a high or low-pressure discharge, LED, glow discharge or other light source.
The light source 18 is electrically powered through two lead connections. The first electrical lead 20 passes through the press-sealed end 16. The first electrical lead 20 has a first end 24 electrically coupled to the light source 18 (filament) and has a second end 26 that is extended along a first axis 27 through the press-seal 16 and then axially away from the press-seal 16, and where second end 26 is exposed on the lamp 10 exterior for electrical connection.
Similarly a second electrical lead 22 passes through the press-sealed end 16, and has a similar first end electrically coupled to the light source (filament) and has a second end extended through the press-seal 16 and then along a second axis 30 and away from the press-seal 16, where the second lead end is also exposed on the lamp 10 exterior for electrical connection.
The second end 26 of the first lead 20, the portioned exposed on the lamp exterior includes two contact faces 32, 34. The first contact face 32 and a second contact face 34 are offset one from the other, generally having a width and breadth sufficient to make good electrical contact in a wedge type socket, and generally planar in form (or modified planar as described below). Each of the two contact faces 32, 34 is approximately parallel to each other. Approximately parallel here means, actually parallel or within about 25 degrees of being parallel. The two contact faces 32, 34 may be frictionally wedged in contact with corresponding socket faces. When the contact faces 32, 34 are actually closely parallel; the socket may be formed with corresponding faces to frictionally pinch the second lead end along the two exposed contact faces 32, 34. As the angle of inclination between the two contact faces 32, 34 increases, it becomes more difficult to securely pinch the two contact faces 32, 34 in electrical and mechanical contact. The preferred contact faces 32, 34 are approximately planar, as they are easily manufactured that way, but they may be curved, toothed, staircased, rippled or similarly shaped. It is only important the contact faces 32, 34 slidingly pass against corresponding mating faces formed on a retaining socket, and are subsequently reasonably retained in position mated to the corresponding socket faces. The preferred second end of the second lead 22 similarly includes a similar first contact face and a second contact face, the first contact face and the second contact face of the second lead 22 are also offset one from the other with each being approximately parallel to each other and to the second lead axis. In the preferred embodiment the contact faces 32, 34 of the first lead 20 and the similar faces of the second lead 22 are all approximately parallel with the broad faces of the press-seal 16.
In a preferred embodiment, each second lead end (26) is formed as a cylindrical rod that extends from the press-seal 16, approximately parallel to the other second lead end (shaft). Welded to each of the distal ends of the shafts are U shaped resilient pieces 40, 42 formed from flat stock metal. The first U piece 40 has an interior face 44 that is welded to the exposed lead end 26. The first U piece 40 has a second interior face 46 that offset from the lead end 26 with a gap 48 formed between the lead end 26 and the second U interior face 46. The exterior faces the U shape piece 40 form the contact faces 32, 34. The U shape piece 40 has a bottom side 50 that forms a wedge that initially enters and centers the contact faces 32, 34 against corresponding socket faces. In the preferred embodiment, the U piece 40 is anchored to the exposed lead end 26, for example by welding. The second side of U piece 40, between faces 34 and 46 acts as resilient spring tensioning the contact faces 32, 34 against corresponding socket faces. It is understood that the socket faces may include resilient mating faces for contacting the contact faces 32, 34. In this way the lamp 10 may be wedged into the socket, and held in place by friction or spring tension.
The wedge contacts may be applied to the ends of heavier lead wires typical of larger lamps, thereby enabling the use of larger lamps in existing wedge type sockets. The more efficient, or longer-lived, albeit larger lamps including tungsten halogen type lamps may then be used in wedge type sockets. While there have been shown and described what are at present considered to be the preferred embodiments of the invention, it will be apparent to those skilled in the art that various changes and modifications can be made herein without departing from the scope of the invention defined by the appended claims.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4429249 | Tyler et al. | Jan 1984 | A |
| 5093601 | Watanabe et al. | Mar 1992 | A |
| 6411021 | Izawa et al. | Jun 2002 | B1 |
| Number | Date | Country | |
|---|---|---|---|
| 20060145583 A1 | Jul 2006 | US |
