Information
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Patent Grant
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6830471
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Patent Number
6,830,471
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Date Filed
Monday, June 9, 200321 years ago
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Date Issued
Tuesday, December 14, 200419 years ago
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Inventors
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Original Assignees
-
Examiners
Agents
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CPC
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US Classifications
Field of Search
US
- 439 342
- 439 263
- 439 884
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International Classifications
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Abstract
An electrical contact (1) includes a medial portion (10), two upper arm portions (11), and a lower solder portion (12). The medial portion includes two sidewalls (100), and an engaging portion (101) below one sidewall. The solder portion depends from the engaging portion. Each arm portion extends from a top of a respective sidewall, and is deflectable from a rest position to a deflected position by a corresponding horizontally actuatable mating pin (2). Each arm portion includes a top contact portion (110), and a guiding portion (111) extending obliquely from an end of the contact portion. The guiding portion has an inner convex side (1112) and a bottom edge (1110). The contact portion also has an inner convex side (1101). As each arm portion is deflected from the rest position to the deflected position, the pin contacts a contact section of the arm portion located above the bottom edge.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to electrical contacts, and particularly to electrical contacts used in electrical connectors for connecting electronic packages such as pin grid array (PGA) central processing units (CPUs) with circuit substrates such as printed circuit boards (PCBs).
2. Description of the Prior Art
Zero insertion force, low actuation force connectors are widely used for electrically connecting PGA CPUs with PCBs. Usually, these connectors comprise an insulative base and a plurality of contacts received in the base. Examples of such connectors are disclosed in U.S. Pat. No. 6,319,038 and TW Patent Issue No. 472962. Referring to
FIGS. 3 and 4
, each contact
6
comprises a medial portion
60
, a solder portion
62
depending from the medial portion
60
, and a pair of arm portions
61
extending upwardly from the medial portion
60
. The medial portion
60
has a U-shaped horizontal cross-section. The medial portion
60
comprises a pair of sidewalls
600
parallel to each other, and an engaging member
601
below one of the sidewalls
600
. The engaging member
601
has several protrusions, for engaging with an insulative base (not shown) and thereby mounting the contact
6
in the base. The solder portion
62
extends downwardly from a bottom of the engaging member
601
, for electrically connecting with a PCB (not shown). Each arm portion
61
extends upwardly from a top of a respective sidewall
600
, thereby defining a first line
602
at a junction of the sidewall
600
and the arm portion
61
. The arm portions
61
are bent obliquely toward each other, and are each deflectable from a rest position to a deflected position (as depicted with broken lines in
FIG. 4
) by a corresponding horizontally actuatable pin
8
of a CPU. Each arm portion
61
comprises a contact portion
610
at a top end thereof, and guiding portion
611
extending obliquely from an end of the contact portion
610
. The contact portions
610
of the arms
61
are parallel to each other, and define a first distance therebetween. A second line
613
is defined at a bottom edge of each contact portion
610
and its adjacent guiding portion
611
. The guiding portions
611
of the arms
61
extend obliquely away from each other, thereby defining a second maximum distance therebetween. The second distance is greater than the first distance.
Referring particularly to
FIG. 4
, in use, the pin
8
is inserted into a space between the free ends of the guiding portions
611
. The second distance is greater than a diameter of the pin
8
. Accordingly, the pin
8
is inserted with zero insertion force as between the contact
6
and the pin
8
, and each arm portion
61
remains in the rest position. Then the pin
8
is moved horizontally toward the contact portions
610
. Opposite side portions of a leading periphery of the pin
8
eventually contact insides of the guiding portions
611
, whereupon an actuation force is applied to drive the pin
8
further. Finally, the pin
8
is received between the contact portions
610
. During driving of the pin
8
, a desired radius of leverage corresponding to the actuation force is represented by distance ‘b’. However, in fact, as can be seen from the broken lines of
FIG. 4
, when the pin
8
contacts the insides of the guiding portions
611
, the arm portions
61
deflect outwardly with respect to the first lines
602
toward respective deflected positions. The pin
8
contacts a contact point of each guiding portion
611
which is located on the second line
613
, and the radius of leverage corresponding to the actuation force is in fact distance ‘b prime’ (‘b’). Thus, the actuation force required to drive the pin
8
into the contact
6
is greater than desired.
In view of the above, a new electrical contact that overcomes the above-mentioned disadvantages is desired.
SUMMARY OF THE INVENTION
Accordingly, an object of the present invention is to provide an electrical contact used in an electrical connector, whereby friction between the contact and a corresponding mating pin is minimized.
Another object of the present invention is to provide an electrical contact used in an electrical connector, whereby minimal actuation force is required to drive a corresponding mating pin into engagement with the contact.
To achieve the above-mentioned objects, an electrical contact in accordance with a preferred embodiment of the present invention is used in an electrical connector. The contact is for engaging with a corresponding horizontally actuatable pin of a CPU. The contact comprises a medial portion, a pair of arm portions extending from a top of the medial portion, and a solder portion depending from a bottom of the medial portion. The medial portion comprises an engaging portion for engaging with an insulative base of the connector. The solder portion depends from a bottom of the engaging portion, for engaging with a PCB. Each arm portion is deflectable from a rest position to a deflected position by the pin. Each arm portion comprises a contact portion at a top end thereof, and a guiding portion extending obliquely from an end of the contact portion. The guiding portion comprises an inner convex side and a bottom edge. The contact portion also has an inner convex side. As each arm portion is deflected from the rest position to the deflected position, the pin contacts a contact section of the arm portion, the contact section being located above the bottom edge.
Other objects, advantages and novel features of the invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings, in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1
is an isometric view of an electrical contact for an electrical connector in accordance with the preferred embodiment of the present invention;
FIG. 2
is a front side plan view of the electrical contact of
FIG. 1
, showing a corresponding mating pin (represented by broken lines) of a CPU engaging with the contact;
FIG. 3
is an isometric view of a conventional electrical contact; and
FIG. 4
is a front side plan view of the electrical contact of
FIG. 3
, showing a corresponding mating pin (represented by broken lines) of a CPU engaging with the contact.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION
Reference will now be made to the drawings to describe the present invention in detail.
Referring to
FIGS. 1 and 2
, an electrical contact
1
of the present invention is used in an electrical connector (not shown). The electrical connector is for electrically connecting an electronic package such as a pin grid array (PGA) central processing unit (CPU) with a circuit substrate such as a printed circuit board (PCB). The CPU comprises a plurality of horizontally actuatable pins
2
(only one shown). The electrical connector has an insulative base (not shown) for receiving a plurality of the contacts
1
therein.
Each contact
1
is stamped and formed from a metallic sheet. The contact
1
comprises a medial portion
10
, a pair of arm portions
11
extending from a top of the medial portion
10
, and a solder portion
12
depending from a bottom of the medial portion
10
. The medial portion
10
has a U-shaped horizontal cross-section. The medial portion
10
comprises two parallel sidewalls
100
, and an engaging portion
101
below one of the sidewalls
100
. The engaging portion
101
comprises several protrusions
1011
, for engaging with the base and thereby mounting the contact
1
in the base. The solder portion
12
depends from a bottom of the engaging portion
101
, for electrically connecting with the PCB. Each arm portion
11
extends from a top of a respective sidewall
100
, thereby defining a first line
112
at a junction of the sidewall
100
and the arm portion
11
. The arm portions
11
are bent obliquely toward each other, and are each deflectable from a rest position to a deflected position (as depicted with broken lines in
FIG. 2
) by a corresponding pin
2
. Each arm portion
11
comprises a contact portion
110
at a top end thereof, and a guiding portion
111
extending obliquely from an end of the contact portion
110
. The guiding portions
111
of the arm portions
11
extend obliquely away from each other. Each guiding portion
111
comprises an inner convex side
1112
, and a bottom edge
1110
. The contact portion
110
also comprises an inner convex side
1101
. The contact portions
110
of the arm portions
11
define a first minimum distance therebetween. The guiding portions
111
of the arm portions
11
define a second distance between respective free ends thereof. The second distance is greater than the first distance.
Referring particularly to
FIG. 2
, in use, the pin
2
is inserted into a space between the free ends of the guiding portions
111
. The second distance is greater than a diameter of the pin
2
. Accordingly, the pin
2
is inserted with zero insertion force as between the contact
1
and the pin
2
, and each arm portion
11
remains in the rest position. Then the pin
2
is moved horizontally toward the contact portions
110
. Opposite side portions of a leading periphery of the pin
2
eventually contact the convex sides
1112
of the guiding portions
111
, whereupon an actuation force is applied to drive the pin
2
further. The arm portions
11
deflect outwardly with respect to the first lines
112
toward respective deflected positions. As can be seen from the broken lines of
FIG. 2
, when the pin
2
contacts the convex sides
1112
of the guiding portions
111
, it contacts a medial contact point (not labeled) of each guiding portion
111
because each guiding portion
111
is convex. Further, when the pin
2
enters between the contact portions
110
, it contacts a medial contact point
1100
of each contact portion
110
because each contact portion
110
is convex. The contact points (not labeled) of the guiding portions
111
and the contact points
1100
are all located above the corresponding bottom edges
1110
. A radius of leverage corresponding to said actuation force is represented by ‘c’ in FIG.
2
. The radius c is greater than the corresponding radius b′ for the conventional contact
6
shown in FIG.
4
. Thus, said actuation force required to drive the pin
2
into the contact
1
is less than that required for the conventional contact
6
.
While a preferred embodiment in accordance with the present invention has been shown and described, equivalent modifications and changes known to persons skilled in the art according to the spirit of the present invention are considered within the scope of the present invention as defined in the appended claims.
Claims
- 1. An electrical contact for engaging with a transversely actuatable pin, the electrical contact comprising:a medial portion having a U-shaped horizontal cross-section and comprising two parallel sidewalls and an engaging portion extending from a lower section of one of the sidewalls; a pair of arm portions extending from an upper section of the sidewalls of the medial portion respectively and bending obliquely toward each other, each of the arm portions being deflectable from a rest position to a deflected position by the pin, each of the arm portions comprising a contact portion at an end thereof and a guiding portion extending obliquely from the contact portion, the guiding portion comprising an inner convex side and a bottom edge, tile contact portion comprising an inner convex side, wherein when each of the arm portions is deflected from the rest position to the deflected position, the pin contacts a contact section of the arm portion located above the bottom edge; and a solder portion extending from a lower section of the engaging portion of the medial portion.
- 2. The electrical contact as claimed in claim 1, wherein the engaging portion comprises a plurality of protrusions, for engaging with a base of an electrical connector.
- 3. An electrical connector adapted for electrically connecting a central processing unit (CPU) having a plurality of transversely actuatable pins with a printed circuit board (PCB), the electrical connector comprising:an insulative base; a plurality of contacts received in the base, each of the contacts comprising: a medial portion comprising a pair of sidewalls parallel to each other, and an engaging portion depending from a bottom of one of the sidewalls; a pair of arm portions each deflectable from a rest position to a deflected position by a corresponding pin, the arm portions extending from tops of the sidewalls respectively and bending obliquely toward each other, each of the arm portions comprising a contact portion at an end thereof and a guiding portion extending obliquely from an end of the contact portion, the guiding portion comprising an inner convex side and a bottom edge, the contact portion comprising an inner convex side, wherein when each of the arm portions is deflected from the rest position to the deflected position, the pin contacts a contact section of the arm portion located above the bottom edge; and a solder portion extending from a bottom of the engaging portion.
- 4. The electrical connector as claimed in claim 3, wherein the engaging portion of each of the contacts comprises a plurality of protrusions for engaging with the base.
- 5. An electrical contact assembly comprising:a conductive contact defining a U-shaped medial portion; a pair of arm portions integrally extending upwardly from upper portions of two parallel spaced side walls of said medial portion and bending obliquely toward each other; a pair of contact portion located on top portions of the pair of arm portions, respectively, a pair of guiding portions horizontally and obliquely extending forwardly from the corresponding pair of contact portions, respectively, and defining therebetween a first space larger than a second space defined between the corresponding pair of contact portions; at least said pair of contact portions being convexly coined toward each other along a horizontal direction thereof; and a pin moving between the pair of arm portions and along the guiding portions and the contact portions in a front-to-back direction to have the pair of arm portions outwardly deflected away from each other about fulcrums each located around a junction of the arm portion and the corresponding side wall; wherein engagement between the pin and the contact assuredly occurs only on the convexly coined contact portions rather than any other portions of the contact once the pin is moved to a final position between said pair of contact portions.
- 6. The electrical contact assembly as claimed in claim 5, wherein said pair of guiding portions are convexly coined toward each other along said horizontal direction to comply with said pair of contact portions.
- 7. The electrical contact assembly as claimed in claim 5, wherein said guiding portion is located at a same height with the corresponding contact portion.
Priority Claims (1)
Number |
Date |
Country |
Kind |
91218818 U |
Nov 2002 |
TW |
|
US Referenced Citations (12)