Socket for electric part

Abstract: A socket for an electric part has a socket body (1) formed of an insulating material and a plurality of contacts (2) arranged on the socket body and adapted to contact with terminals of an electric part. The socket body has a conductive pin (64) implanted therein. The conductive pin has a current-collecting portion (6c)adapted to collect electric charge on a surface of the socket body, and a grounding portion (6b) directly connected to the current-collecting portion and projecting from the socket body.

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to a socket for an electric part, which makes it possible, on the socket side, to effectively eliminate static electricity which frequently exerts an adverse effect on an electric part. 2. Statement of the Prior Art As a measure for eliminating static electricity in the conventional socket for an electric part such as IC, etc., a conductive resin is employed as a material for forming a socket body or means for irradiating ion to the socket body is practised. However, the socket formed of a conductive resin has such a problem as that leak of electric current occurs due to irregularity of insulation resistance values, while the socket provided with the ion irradiation means has such a problem as that a large-scaled equipment for irradiating ion is required. EP-A-0,095,877 discloses a socket in accordance with the preambles of Claims 1 and 2. US-A-4,711,506 discloses a socket having the features of the preamble of Claim 3 and provided with an earth spring for grounding static electricity in a user's body before a plug is plugged into the socket. SUMMARY OF THE INVENTION It is therefore a general object of the present invention to provide, in order to obviate the above-mentioned problems, a socket for an electric part which is capable of effectively eliminating static electricity charged on the surface of the socket with simple and inexpensive means. The invention provides a socket in accordance with Claim 1 or Claim 2 or Claim 3. According to the present invention, the electric charge on the surface of the socket body formed of an insulating material is collected by the current-collecting portion disposed in such a manner as to contact with the surface of the socket body, and such collected electric charge is rapidly released through the grounding portion connected to a circuit board, etc. At that time, by slide-fitting the current-collecting portion of the conductive pin to the contacting and releasing movable plate, even the static electricity on the surface of the movable plate can satisfactorily be eliminated. Furthermore, by providing means for short-circuiting the current-collecting portion of the conductive pin to the shafts pivotally supporting the lateral movement operating lever of the movable plate, the electric part pressing cover, etc., the effect of elimination of static electricity can remarkably be enhanced. The present invention can be practiced at a low cost by such handy means as that the conductive pin having the above-mentioned elements is implanted into the socket body in such an arrangement as mentioned above and is capable of effectively achieving the originally intended object. The above object of and advantages obtained by the present invention will become apparent from the accompanying drawings and the detailed description of the invention to follow. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an exploded perspective view of a socket for an electric part shown in the first embodiment of the present invention; Fig. 2 is a side view, partly in section, of the socket for an electric part; Fig. 3 is a side view, partly in section, of the socket for an electric part showing the third embodiment of the present invention; Fig. 4 is an exploded perspective view of a socket for an electric part showing the fourth embodiment of the present invention; Fig. 5 is a side view, partly in section, of the socket for an electric part; and Fig. 6 is a side view, partly in section of a socket for an electric part showing the fifth embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS Several preferred embodiments of the present invention will now be described with reference to Figs. 1 through 6. First Embodiment (see Figs. 1 and 2) The numeral 1 denotes a socket body formed of an insulating material. The socket body 1 includes a plurality of contacts 2 arranged in such a manner as to be able to contact with an electric part such as IC, etc. The numeral 3 denotes a contacting and releasing movable plate closed on the surface of the socket body 1 and laterally movable along the surface. The movable plate 3 includes a plurality of through holes 4 adapted to permit terminals of an electric part placed on the movable plate to be inserted therein so as to contact with the corresponding contacts 2. The numeral 5 denotes a lateral movement operating lever of the movable plate 3. The lever 5 has a cam shaft 5a interposed between the closed ends of the movable plate 3 and the socket body 2, and an operating portion directly connected to an end portion of the cam shaft 5 and extending in parallel with the side surface of the socket body 1. Upon pivoting operation of the operating portion 5b either in its rising direction or in its collapsing direction, the cam shaft 5a is pivoted. Depending on the pivoting direction of the cam shaft 5a, an eccentric shaft portion causes the movable plate 3 to be laterally moved in one direction or in the other direction, so that the terminals of the electric part and contacts 2 are brought into contact with each other or released from each other. The above-mentioned socket for an electric part is suitably used as a socket for a pin grid array type IC having a plurality of terminals projecting from a lower surface of a flat IC body. The socket body 1 of such constructed socket for an electric part as mentioned above is provided with a conductive pin 6. The conductive pin 6 includes a current-collecting portion 6a and a grounding portion directly connected to a lower end of the current-collecting portion 6a. The current-collecting portion 6a is embedded in the socket body 1 in such a manner as either to be press-fitted into a hole 7 opened at the surface of the socket body 1 or to mold therein when the socket body 1 is molded. An upper end portion (see Fig. 2) of the current-collecting portion 6a projects upwardly from the surface of the socket body 1 to form a current-collecting head portion 6c, and the current-collecting head portion 6c is slide-fitted in an elongate hole 8 formed in the movable plate 3 and serving also as a guide for the movement of the movable plate 3. The grounding portion 6b of the conductive pin 6 projects downwardly of the socket body 1 so as to facilitate its easy contact with a circuit board, etc. Owing to the foregoing arrangement, the current-collecting portion 6a is contacted with the surface of the socket body 1 by means of its intimate contact with the edge portion and the inner wall of the hole 7, and the current-collecting portion 6a is further contacted with the surface of the movable plate 3 by means of the intimate contact between the current-collecting portion 6c and the hole 8 in order to collect electric charge on the surfaces of the socket body 1 and the movable plate 3. The current-collecting pin 6 is preferably formed in a round pin shape, for example, the current-collecting portion 6a being formed in a round pin of a large diameter and the grounding portion 6b being formed in a round pin of a small diameter, and therefore, the current-collecting pin 6 being formed in a two-stage pin. The implanting depth of the current-collecting pin 6 is set at the stage portions of the current-collecting portion 6a and the grounding portion 6b, and a wholesome contacting relation between the current-collecting portion 6a and the inner wall of the hole 7 is obtained. Preferably, by means of the setting of the implanting depth, the distal end face of the current-collecting head portion 6c is arranged to be a generally equal level with respect to the surface of the movable plate 3 to realize a favorable contacting relation with the surface of the movable plate 3, so that the effect of current collection is enhanced. The conductive pin 6 is operated to guide the lateral movement of the movable plate 3 and also functions as the current-collecting means. Second Embodiment (see Fig. 3) In this embodiment, the conductive pin 6 is embedded in the socket body 1 through the grounding portion 6b (or the current-collecting portion 6a), and the lower surface of the current-collecting portion 6a is arranged to sit on the surface of the socket body 1 in order to attain its contacting relation with the surface of the socket body 1. Further, it employs means for short-circuiting the current-collecting portion 6a to conductive shafts 11 and 12 adapted to pivotally support a pressing cover 9 or a lock lever 10. For example, the current-collecting portion 6a is provided with a groove 13 formed in an end face thereof, and the shafts 11 and 12 are fitted in the groove 13 to attain the contacting relation. The socket body 1 is provided at one end thereof with the pressing cover 9 and at the other end with the lock lever 10. The arrangement being such that the pressing cover 9 is closed to press an electric part 16 and the lock lever 10 is engaged with the free end of the pressing cover 9 to maintain the closed state and the contacted state. In the above embodiment, by utilizing the conductive shafts 11 and 12 pivotably supporting the pressing cover 9 or the lock lever 10, these shafts 11 and 12 and the current-collecting portion 6a are short-circuited with respect to each other, thus enabling them to cooperate with each other to provide means for eliminating the static electricity. The above embodiment can suitably be practiced as a leadless type IC socket. Third Embodiment (see Figs. 4 and 5) In this third embodiment, the current-collecting portion 6a is bifurcated, so that the shafts, etc. originally had by the socket are clamped by the forked parts of the current-collecting portion 6a. In this respect, this embodiment is in common with the third embodiment. More specifically, the cam shaft 5a of the lateral movement operating lever 5 of the movable plate 3 described in the first embodiment is clamp-contacted by the forked parts of the current-collecting portion 6a. That is, the socket body 1 has a groove 13a formed in the surface thereof and adapted to accommodate the cam shaft 5a therein. The conductive pin 6 is embedded in the socket body 1 such that the forked inner surfaces of the current-collecting portion 6a are exposed to the inner surface of the groove 13a. The arrangement being such that when the cam shaft 5a is fitted in the groove 13a, it is automatically fitted to and clamp-contacted by the forked parts of the current-collecting portion 6a. Further, the cam shaft 5a is contacted with the fork-shaped inner surfaces and pivoted to cause the movable plate 3 to move in the lateral direction. Fourth Embodiment (see Fig. 6) In this fourth embodiment, the socket for an electric part includes a contacting and releasing movable plate 3. As lateral movement operating means of the movable plate 3, one end of the lever 5 is pivotally supported by separate shafts 14 and 15 at one ends of the socket body 1 and movable plate 3. The arrangement being such that by pivotally rotating the lever 5 in the rising direction or in the collapsing direction about the shaft 14, the shaft 15 is caused to pivot in order to move the movable plate 3 in the lateral direction. On the other hand, the conductive pin 6 is bifurcated at the current-collecting portion 6a and implanted in the socket body 1, so that the shaft 14 is slide-fitted to and clamp-contacted with the forked inner surfaces of the current-collecting portion 6a, thus enabling to collect the static electricity. In the respect that the conductive pin 6 is short-circuited to the pivotable shaft, this embodiment is in common with the third and fourth embodiments in which the conductive pin 6 is short-circuited to the shafts 11, 12 and 5a of the pressing cover 9 and the lock lever 10 or the lateral movement operating lever 5 of the movable plate 3. As described in the foregoing, according to the present invention, the electric charge on the surface of the socket for an electric part can be collected by the current-collecting portion which is conductively connected to the surface of the socket and such collected electric charge can rapidly be released by the grounding portion. Accordingly, the socket for an electric part according to the present invention can effectively be practiced as a measure for eliminating static electricity which frequently exerts adverse affection to an electric part. Further, by utilizing the shafts of the pressing cover, the lateral movement operating lever of the movable plate, etc. originally had by the socket and by further providing means for short-circuiting the current-collecting portion of the conductive pin thereto, they can cooperate with each other to significantly enhance the effect of elimination of the static electricity. According to the present invention, the originally intended object can be achieved by such simple and inexpensive way as that the current-collecting pin is implanted in the socket body. While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from the scope of the invention as defined by the appended claims.

Claims: A socket for an electric part including a socket body (1) formed of an electric insulative material, a plurality of contacts (2) arranged on said socket body (1) so as to be able to contact terminals of an electric part (16), and a movable plate (3) capable of moving laterally along an upper surface of said socket body (1) so that the terminals of the electric part (16) and said contacts (2) can be brought into or out of contact with each other, characterized in that said socket body (1) having electric conductive pins (6) implanted therein, said pins (6) each including a current-collecting portion (6a) adapted to collect electric charge on the upper surface of said socket body (1) and a grounding portion (6b) connected directly to said current-collecting portion (6a) and projecting from said socket body (1), said current-collecting portions (6a) of said electric conductive pins (6) being slide-fitted into elongated holes (8) formed in said movable plate (3). A socket for an electric part including a socket body (1) formed of an electric insulative material, a plurality of contacts (2) arranged on said socket body (1) so as to be able to contact terminals of an electric part (16), and a movable plate (3) capable of moving laterally along an upper surface of said socket body (1) so that the terminals of the electric part (16) and said contacts (2) can be brought into or out of contact with each other, characterized in that said socket body (1) having electric conductive pins (6) implanted therein, said pins (6) each including a current-collecting portion (6a) adapted to collect electric charge on the upper surface of said socket body (1) and a grounding portion (6b) connected directly to said current-collecting portion (6a) and projecting from said socket body (1), said current-collecting portions (6a) of said electric conductive pins (6) being short-circuited to a shaft portion (5a or 14) of an electric conductive lever (5) adapted to laterally move said movable plate (3). A socket for an electric part including a socket body (1) formed of an electric insulative material, and a plurality of contacts (2) arranged on said socket body (1) so as to be able to contact terminals of an electric part (16), characterized in that said socket body (1) having electric conductive pins (6) implanted therein, said pins (6) each including a current-collecting portion (6a) adapted to collect electric charge on the upper surface of said socket body (1) and a grounding portion (6b) connected directly to said current-collecting portion (6a) and projecting from said socket body (1), said current-collecting portions (6a) of said electric conductive pins (6) being short-circuited either to an electric conductive shaft (11) for pivotably supporting a presser cover (9) for pressing the electric part placed in said socket body (1), or an electric conductive shaft (12) for pivotably supporting a lock lever (10).

Inventors: MATSUOKA NORIYUKI, URATSUJI KAZUMI C O YAMAICHI E, MATSUOKA, NORIYUKI, URATSUJI, KAZUMI, C/O YAMAICHI ELEC. MFG. CO., LTD
Applicants: YAMAICHI ELECTRONICS CO LTD, YAMAICHI ELECTRONICS CO., LTD.
Application year: 1991
Main classification: H01R13
IPC codes: H05F3, H01R33, H01R13, H05K7