Patent Grant
7025634
This invention relates to lamp sockets and more particularly to lamp sockets for bi-pin lamps. Still more particularly, it relates to lamp sockets utilizing novel electrical contacts.
Previous lamp sockets for bi-pin lamps have employed tangential contacts, which forced the contact points to change dramatically as the mating lamp pin was inserted, producing and increasing insertion force as the pin was inserted into the socket. This condition made it difficult to determine if the bulb was completely seated in the socket. Additionally, prior contacts often had to be plated to achieve the high conductance levels needed to transmit high current levels to the lamp. The plating was subject to wear, thus limiting the life of the socket.
It is, therefore, an object of the invention to obviate the disadvantages of the prior art.
It is another object of the invention to enhance the seating of bi-pin lamps into an appropriate socket.
It is yet another object of the invention to lengthen socket life.
These objects are accomplished, in one aspect of the invention, by the provision of an electrical contact comprising a substantially U-shaped body having an open end and a bight, the U-shaped body comprising a contact portion formed of a first material nested within a substantially contiguous spring portion formed of a second material. This two-piece contact design allows the contact to be compliant for an entire range of tolerances. Further, it allows the contact to have a material with a relatively high conductance for contacting the mating lamp pin. The terminal does not require plating, thus providing extremely long life.
The objects are further accomplished by the provision of socket for a bi-pin lamp. The socket comprises an electrically insulating primary housing including a receptacle, and a secondary housing formed to be received in the receptacle. The secondary housing has a body with a pair of recesses therein. The recesses have a floor including a pin-receiving aperture. A substantially U-shaped electrical contact is positioned in each recess with the open ends thereof facing the floor, each of the electrical contacts comprising a contact portion formed of a first material nested within a substantially contiguous spring portion formed of a second material.
For a better understanding of the present invention, together with other and further objects, advantages and capabilities thereof, reference is made to the following disclosure and appended claims taken in conjunction with the above-described drawings.
Referring now to the drawings with greater particularity, there is shown in
The contact portion 18 of the electrical contact 10 has a protrusion 22 formed in the bight 16a thereof, the protrusion 22 being fitted into a matching opening 24 in the bight 16b of the spring portion 26. The protrusion 22 can be formed during the formation of the contact portion 18 and be friction-fitted into the opening 24 or, preferably, it can be formed directly into the opening 24, as by a coining operation after the contact portion and the spring portion are nested together.
The bights 16a and 16b of the contact portion 18 and the spring portion 20 include first and second oppositely directed tabs 26, 28 that, in the case of tabs 26, fit into slots 60 in recesses 50 to aid in locating and stabilizing the contact 10 and allow it to float in the recess and, in the case of tabs 28, provide support for the projecting wire-engaging member 30 that is formed on bight 16a of the contact portion 18 as an extension of a tab 28. These features are illustrated in
The secondary housing 46 includes a through-hole 62 to receive a rivet 64 or other fastening device for securing an electrically insulating cover 66 formed, for example, of mica, to the housing 46 to maintain the contacts 10 within the recesses 50.
A gap 70 exists between the contact portion 18 and the spring portion 20 near the bight 16 to insure that spring portion 20 and contact portion 18 are touching at the pin engagement area 72.
Thus there is provided an enhanced bi-pin lamp socket whose dual cantilevered beam design provides two well defined points of contact for the mating pins. Further, the two-piece design allows the contact to be compliant through an entire range of tolerances while also allowing for the use of a contact material having a relatively high conductance mate with the pins. The contact does not require plating to achieve this effect thereby greatly extending the life of the contact.
While there have been shown and described what are 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 as defined by the appended claims.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4391485 | Urani | Jul 1983 | A |
| 4472018 | Urani | Sep 1984 | A |
| 5120242 | Greiler et al. | Jun 1992 | A |
