Electrical connectors – With coupling movement-actuating means or retaining means in... – Including compound movement of coupling part
Reexamination Certificate
2003-01-17
2004-03-30
Nguyen, Truc T (Department: 2833)
Electrical connectors
With coupling movement-actuating means or retaining means in...
Including compound movement of coupling part
C438S259000, C438S268000
Reexamination Certificate
active
06712634
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention generally relates to a socket assembly that is designed to reduce bowing during actuation.
Pin grid array (PGA) sockets are used to accept electronic packages on printed circuit boards. PGA sockets facilitate electrical communication between a large number of pins born on an electronic processor and electrical components to which the PGA sockets are mounted (such as circuit boards). Zero insertion force (ZIF) PGA sockets utilize a cover that is slidably movable on a base between open and closed positions. The sliding movement may be actuated, for example, by a cam that is rotated by a hand tool. The cover has a hole array configured to match a pin array on a processor. Similarly, the base has an array of pin receiving chambers configured to accept the pin array of the processor. The processor is mated to the socket by first placing the processor such that its pins penetrate the holes of the cover. With the cover in the open position, the pins penetrate through the holes of the cover and into the pin receiving chambers of the base but are not electrically connected to the pin receiving chambers of the base. When the cover is slid to the closed position, the pins are electrically connected to the base via the pin receiving chambers.
Because there may be hundreds of pins in the array, moving the cover to the closed position can require a considerable force to move the pins into their fully mated position. This force can cause the socket assembly to bow, resulting in inadequate actuation and/or de-actuation.
FIG. 1
illustrates an example of a prior art socket system
10
with a cam actuation mechanism. The socket system
10
includes a cover
12
slidably mounted to a housing
14
. The housing
14
is mounted to a board (not shown) by solderballs
16
. The socket system
10
includes a cam
18
that is accepted by both the cover
12
and the housing
14
. Rotation of the cam
18
results in the cover
12
moving along direction A relative to the housing
14
. The cover
12
moves to the right in
FIG. 1
when closed (or actuation) and to the left when opened (or de-actuation). The socket system
10
also includes a housing wear plate
20
that nests in the housing
14
and contacts the cam
18
along a bearing surface of the cam
18
as the cam
18
is rotated, and a cover wear plate
21
that nests in the cover
12
and also contacts the cam
18
along a bearing surface as the cam
18
is rotated. The cam
18
includes an eccentric portion that contacts the cover wear plate
21
, causing the cover
12
to move laterally as the cam
18
is rotated.
When the cam
18
is rotated, resultant forces are exerted on the housing
14
from the cam
18
via the housing wear plate
20
. When the cover
12
is being actuated, a resultant force occurs at closing push surface
22
. When the cover
12
is being de-actuated, a resultant force occurs at opening push surface
24
. These resultant forces create a moment about the solderballs
16
at which the housing
14
is mounted. The horizontal portions of the moment arms are the opening moment arm
26
and the closing moment arm
28
, and correspond to the opening push surface
24
and closing push surface
22
, respectively. The moments caused by the resultant forces cause bowing and deflection along bowing direction B. Further, the resultant forces at the opening push surface
24
can cause wear and cracking at a back edge
30
of the housing
14
.
For the socket system
10
illustrated in
FIG. 1
, closing or actuation causes deflection downward along bowing direction B. In this circumstance, the socket system
10
may be supported by a board to which it is mounted and engagement may be achieved. However, opening or de-actuation causes bowing upward along bowing direction B. Because there is no support available above the socket system
10
, the resulting bowing can prevent disengagement of the socket.
A need remains for a socket assembly that overcomes the above-noted and other disadvantages of existing PGA sockets.
BRIEF SUMMARY OF THE INVENTION
At least one preferred embodiment of the present invention is provided including a socket assembly for receiving electronic packages. The socket assembly includes a cover and a base slidably engaging one another and movable between open and closed positions. The base includes a contact array. The socket assembly also includes a cam member received by the cover and base. Rotation of the cam member actuates a sliding motion between the cover and base. The socket assembly also includes a load bearing member mounted to one of the cover and base. The socket assembly further includes a wear plate mounted about the load bearing member. The wear plate has a cam reception hole accepting the cam member. The load bearing member and the cam member are located different distances from the contact array to reduce the moment caused by the sliding motion between the cover and base.
Optionally, the load bearing feature may extend from a wear plate cavity formed in the base. The distance between the cam member and the contact array is greater than the distance between the load bearing member and the contact array. The load bearing member may include an opening push surface and a closing push surface. The opening push surface transmits a resultant force when the cover is moved toward the open position, and the closing push surface transmits a resultant force when the cover is moved toward the closed position.
The load bearing member may include an oblong raised element including an opening push surface and a closing push surface on opposing sides of the load bearing member. The wear plate may include an opening forming an oblong slot accepting the oblong raised element. The opening includes an opening surface contacting the opening push surface of the load bearing member, and a closing surface contacting the closing push surface of the load bearing member.
In accordance with at least one preferred embodiment, a socket assembly is provided including a housing, a cover, a cam pin, and a housing wear plate. The housing includes an array of contacts. The contacts are mountable to a circuit board at a mounting feature. The housing also includes an opening push surface and closing push surface. The cover is slidably mounted to the housing and movable relative to the housing between an actuated and a de-actuated position. The housing includes a pin grid corresponding to the array of contacts. The cam pin is received by the housing and the cover, and rotation of the cam pin moves the cover between the actuated and de-actuated positions. The cam pin is located farther from the array of contacts than the opening and closing push surfaces. The housing wear plate includes a cam reception hole that receives the cam pin. The cam reception hole has a bearing surface that contacts the cam pin. The housing wear plate transfers actuation forces from the cam pin to the opening and closing push surfaces. The housing wear plate cooperates with the opening push surface and the closing push surface to reduce a resultant moment caused by a sliding motion between the cover and the base.
Optionally, the housing may include a load bearing member extending from a housing wear plate cavity that is formed in the housing. The load bearing member includes at least one of the opening push and closing push surfaces. The housing wear plate includes an opening including at least one of the opening and closing surfaces. The opening receives the load bearing member. The opening may extend through the housing wear plate.
In accordance with at least one preferred embodiment, a socket assembly is provided including a housing, a cover, a cam pin, a cover wear plate, and a housing wear plate. The housing includes an array of contacts that are mountable to a circuit board at a mounting feature. The housing also includes a housing wear plate cavity including a load bearing member extending from the housing wear plate cavity. The load bearing member has an opening push surface and a closing push surface. The co
Nguyen Truc T
Tyco Electronics Corporation
LandOfFree
Moment/bow reducing wear plate does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Moment/bow reducing wear plate, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Moment/bow reducing wear plate will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3285135