Electrical connectors – With insulation other than conductor sheath – Metallic connector or contact secured to insulation
Reexamination Certificate
2002-01-08
2004-10-19
Luebke, Renee (Department: 2833)
Electrical connectors
With insulation other than conductor sheath
Metallic connector or contact secured to insulation
C439S856000
Reexamination Certificate
active
06805591
ABSTRACT:
BACKGROUND OF THE INVENTION
Certain embodiments of the present invention generally relate to electrical contacts and to connector housings for electrical contacts, and more particularly, to apparatus for securing power contacts in connector housings.
Connector housings are designed to hold various types of contacts, including power and signal contacts. Power contacts are used for mid- to high-range servers (e.g., for power applications). Individual power contacts can accommodate up to 48 amps and 600 volts. When eight power contacts are aligned adjacent to one another in a connector housing, each power contact can accommodate 30 amps. Installed power contacts, as well as signal contacts, have solder tails that protrude downward from and out of the connector housing in a predefined pattern. Typically the connector housing and contacts are loaded or dropped onto printed circuit boards such that the solder tails fit through a corresponding pattern of holes in the printed circuit board and may protrude from the opposite side of the printed circuit board. The solder tails are then wave soldered to the printed circuit board.
Power contacts are presently manufactured with a latch that loosely secures the power contacts into a connector housing. The power contact is designed to only be loosely secured in the connector housing due to the combination of expected tolerances in the power contact and in the connector housing. When a power contact is installed, the latch moves into a window on the connector housing, thereby loosely securing the power contact in the connector housing. The tolerances allow for the power contact to travel into the connector housing beyond the final resting position of the power contact so that the latch can pop up into the window. Once the latch enters the window, the power contact can only slightly move rearward until the latch engages the window. The latch, upon engaging the window, restricts any further rearward movement of the power contact.
However, several disadvantages exist with the above noted power contact design, primarily stemming from the fact that the power contact, being loosely secured in the connector housing, remains free to move about within the connector housing after installation. First, the power contact moves within the connector housing when the connector housing is loaded onto the printed circuit board. Because of this movement, the solder tails of the power contacts may not properly align with and fall into the corresponding pattern of receiving holes on the printed circuit board. If loading the connector housing onto the printed circuit board is an automated process, then failure of the solder tails to properly align and fall into the corresponding pattern of receiving holes can result in defective products. If loading the connector housing onto the printed circuit board is a manual process, then failure of the solder tails to properly align and fall into the corresponding pattern of receiving holes, results in delays until the solder tails can be properly placed into the corresponding pattern of receiving holes.
Secondly, movement of the power contact interferes with wave soldering of the solder tails to the printed circuit board. During wave soldering, a wave of solder engages the ends of the solder tails that protrude through the underside of the printed circuit board. As the solder wave engages the solder tails, the solder tails are free to move up and down relative to the printed circuit board. Consequently, solder tails can be displaced upward and then be soldered to the printed circuit board without the ends of the solder tails fully protruding through the underside of the printed circuit board. If the ends of the solder tails do not fully protrude through the underside of the printed circuit board, it is harder to determine by visual inspection whether or not solder connections between the solder tails and the printed circuit board are defective.
The third problem is movement of the power contacts during mating and unmating of connector housings. Movement of the power contacts relative to the connector housing during mating or unmating can result in increased normal forces on the power contacts that can reduce the lifespan of the power contacts.
A need remains for an improved power contact and connection between the power contact and connector housing.
BRIEF SUMMARY OF THE INVENTION
An embodiment of the present invention provides a connector housing and a contact secured therein. The connector housing includes inner walls that define a contact-receiving chamber. The contact-receiving chamber includes a channel along at least a portion of one of the inner walls. The channel is tapered wider at its receiving end, allowing the channel to easily receive a contact retention member portion of the contact. The contact is configured to connect to a mating contact of a mating connector housing. The contact includes a body section having a contact retention member thereon. The contact retention member includes a bulge portion flared outward in a direction transverse to the body section. When the contact is loaded into the housing and the contact retention member is received by the channel, the bulge portion frictionally engages at least one of the inner walls of the contact-receiving chamber. The frictional engagement of the bulge portion to at least one of the inner walls secures the contact within the connector housing. The bulge portion may define an outer envelope of the contact retention member that is both greater than a predetermined thickness of the body section and wider than the channel in the contact-receiving chamber.
Optionally, the contact retention member can have multiple bulge portions flared in opposite directions form one another, or, alternatively, the contact retention member can have a series of rectangular boxes punched in opposite sides of the body section.
The connector housing may have multiple contact-receiving chambers with multiple contacts secured therein. Also, any of the contacts may have a pair of body sections aligned parallel to one another. Correspondingly, the contact-receiving chamber may have two channels separated by a rail for receiving the two contact retention members on the pair of body sections.
The main advantageous feature of certain embodiments of the invention is that the contact can be securely installed in the connector housing. The contact cannot move freely within the connector housing. The connector housing with the contact can be dropped onto a printed circuit board without the contact moving relative to the connector housing, thus, allowing solder tails of the contact to properly fit into corresponding holes on the printed circuit board. Also, the contact remains fixed in place during wave soldering of the solder tails to the printed circuit board, allowing for good solder connections that easily can be identified by visual inspection. Additionally, because the contact remains fixed in place, there is less wear and tear of the power contact from normal forces during mating and unmating of connector housings.
These and other features and embodiments of the present invention are discussed or apparent in the following detailed description of embodiments of the invention.
REFERENCES:
patent: 4018177 (1977-04-01), McKee et al.
patent: 4317609 (1982-03-01), Lapraik
patent: 6383039 (2002-05-01), Yoneyama et al.
Garland Michael Stephen
Ringler Daniel Robert
Shiffler James Charles
Luebke Renee
Tyco Electronics Corporation
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