# Patent

## Title
Connector terminal and electrical connector

## Abstract

A socket terminal includes a movable portion that includes a first extension that extends from a position near a fixed housing in an insertion/extraction direction of a plug connector, a hairpin portion that is continuous with the first extension, and a second extension that is continuous with the hairpin portion and that extends in the insertion/extraction direction toward a movable housing. The movable portion elastically supports the movable housing in such a way that the movable housing is displaceable relative to the fixed housing. The second extension of the movable portion includes a spring portion that is bent in such a way that the width of a gap between the second extension and a base at one end portion of the second extension continuous with the hairpin portion is larger than that at the other end portion of the second extension continuous with the base.

## Background
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a connecter terminal and an electrical connector having a floating structure.
2. Description of the Related Art
As the performance and multifunctionality of automobile electronic appliances and consumer electronic appliances have increased, electrical connectors for connecting printed circuit boards (hereinafter, referred to as “boards”) to each other are increasingly used. Moreover, as electronic appliances have been reduced in size, boards have also been reduced in size and component packing density has increased. At the same time, it is necessary to connect the boards with high reliability.
A floating structure is a known technology for increasing the connection reliability of electrical connectors. In general, a floating structure includes a “fixed housing” mounted on a board, a “movable housing” to be fitted with a connection object, and “terminals”. Each of the terminals includes a movable portion that is elastic and that holds the fixed housing and the movable housing in such away that the fixed housing and the movable housing are displaceable relative to each other. With the floating structure, the movable portion, which is displaceable, can reduce the effect of an error in the positions of the boards are attached relative to each other. Moreover, the movable portion can absorb displacement of the boards relative to each other due to vibration or impact. Therefore, occurrence of poor contact between terminals and cracking and detachment of solder, which is used to join terminals to the board, can be reduced (see Japanese Unexamined Patent Application Publication No. 2007-109600).
Also regarding the electrical connectors having the floating structure and having high connection reliability, reduction in size is needed as electronic appliances have been reduced in size. However, the movable portion, which is a key component of the floating structure, is one of factors that limit reduction in size.
The reason for this is as follows. An electrical connector has a rectangular shape, and a large number of terminals are arranged side by side along the longitudinal direction of the housing in such a way that the plate surfaces of the terminals extend parallel to each other. Typically, the movable portions of the terminals are disposed between a fixed housing and a movable housing in the transverse direction of the housing. Accordingly, it is necessary to provide a movable space, in which the movable portions are disposed and are allowed to be elastically deformed, between the fixed housing and the movable housing. Moreover, the size of the movable space cannot be reduced beyond a certain limit so that the fixed housing and the movable housing can be displaced relative to each other by a sufficient amount in the movable space. Therefore, it is difficult to reduce the size of the entirety of the electrical connector by reducing the size of movable space while maintaining the existing connector structure.
SUMMARY OF THE INVENTION
An object of the present invention, which has been made to solve the problems of existing technologies described above, is to reduce the size of an electrical connector having a floating structure.
To achieve this object, the present invention provides an electrical connector structured as follows. A connector terminal includes a movable portion that elastically supports a movable housing in such a way that the movable housing is displaceable relative to a fixed housing that is fixed to a board, and a base that is attached to the movable housing and that is continuous with the movable portion. The movable portion includes a first extension located near the fixed housing, a hairpin portion, and a second extension located near the movable housing and adjacent to the base. The first extension, the second extension, and the base are arranged side by side. A width of a gap between the second extension and the base at one end portion of the second extension continuous with the hairpin portion is larger than that at the other end portion of the second extension continuous with the base.
In the connector terminal, the second extension may be inclined in such a way that the width of the gap between the second extension and the base increases from the other end portion toward the one end portion.
In the connector terminal, the second extension may include a spring portion that is bent in such a way that the width of the gap between the second extension and the base near the one end portion is larger than that near the other end portion.
In the connector terminal, the base may have a vertical edge that is shaped in such way that the width of the gap between the second extension and the base near the one end portion is larger than that near the other end portion.
With the connector terminal and an electrical connector including the connector terminal, without uniformly increasing the width of a gap between the first extension and the second extension along the longitudinal direction, it is possible to provide a large movable space between the first extension and the second extension in a region opposite the hairpin portion. In addition, without uniformly increasing the width of the gap between the second extension and the base along the longitudinal direction, it is possible to provide a large movable space between the second extension and the base in a region near the hairpin portion. Accordingly, even when the first extension becomes displaced toward the second extension, the first extension does not easily contact the second extension. Moreover, even when the second extension becomes displaced toward the base, the second extension does not easily contact the base.
In particular, in the case where the connector terminal includes the spring portion, the one end portion and the other end portion of the second extension, which are separated from each other with the spring portion therebetween, can be made to extend parallel to the first extension and the base.
Regarding the electrical connector, the cutout portion, which faces the second extension and the hairpin portion, is formed in the side surface of the base facing the movable portion and the movable portion is disposed in a recess formed by the cutout portion. Therefore, the size of the terminal in the width direction can be made smaller than that of a case where a base in which a cutout portion is not formed and a movable portion are arranged side by side in the width direction.
A state in which the movable portion is disposed in a recess formed by the cutout portion refers not only to a state in which the entirety of the movable portion is disposed in the recess formed by the cutout portion but also to a state in which part of the movable portion, such as the second extension and the hairpin portion, is disposed in the recess formed by the cutout portion.
In the electrical connector, a gap-forming portion may be provided between the fixed housing and the first extension of the movable portion, and the movable portion is separated from the fixed housing with the gap-forming portion therebetween.
By forming the gap-forming portion, when the board connection portion is soldered to the board, it is possible to suppress flowing up of flux through a space between the fixed housing and the first extension of the movable portion due to capillary action. Therefore, it is possible to suppress occurrence of defective contact caused by the flowing up of the flux to the contact-point portion.
In the electrical connector, a long-side wall that extends over and covers the hairpin portion of the movable portion may be provided in the movable housing. Because the protective portion extends over and covers the hairpin portion of the movable portion, the movable portion can be protected from, for example, contact from the outside.
In the electrical connector, each of the terminals may include a connection portion that is connected to a board surface of the board and a support portion that separates the fixed housing from the board.
In this case, when the electrical connector is soldered to the board, adhesion of flux to the fixed housing, entry of the flux into a gap between the board and the terminal, and the resulting flowing up of the flux to the terminal portion due to capillary action can be suppressed.
In the electrical connector, the terminal portion may include an elastic piece that elastically supports the contact-point portion, and the contact-point portion may include a front contact-point portion that slidably contacts a contact surface of the conductive connection portion and that wipes off a foreign substance adhering to the contact surface when the connection object is fitted into the electrical connector, and a rear contact-point portion that contacts the contact surface wiped by the front contact-point portion.
Because the contact-point portion includes the front contact-point portion and the rear contact-point portion, even when foreign substances adhere to the contact surface of the conductive connection portion, the front contact-point portion wipes off the foreign substances from the contact surface, and the rear contact-point portion can be conductively connected to the contact surface securely.
Examples of a terminal including a plurality of contact-point portions include a terminal having one elastic piece that elastically supports the plurality of contact-point portions and a terminal having a plurality of elastic pieces each of which elastically supports a contact-point portion. For either of these terminals, with the present invention, the size of the electrical connector can be reduced in the width direction of the terminal. However, for example, in the case of the former terminal, the effect of the present invention in reducing the size of the electrical connector is particularly effective in a case where the elastic piece is bent in the opposite direction so as to be separated from the conductive connection portion and plate surfaces are arranged in the width direction of the terminal. Likewise, in the case of the latter terminal, the effect of the present invention is particularly effective in a case where the plurality of elastic pieces are arranged in the width direction of the terminal.
In the electrical connector, each of the terminals may have a flat shape that is not bent in a plate surface direction.
In this case, as described above, the size of the terminal can be reduced in the direction parallel to the plate surface and in the thickness direction. Therefore, a large number of terminals can be arranged at a small pitch and it is possible to realize an electrical connector that is compact in a direction in which the terminals are arranged. The terminal may be formed by press-punching a flat electroconductive metal plate.
With the present invention, the size of the electrical connector can be reduced in the width direction of the terminal. Therefore, for example, the size of a floating connector, which includes a fixed housing and a movable housing, can be reduced in the width direction. By using the electrical connector, it is possible to mount components on a board with an increased density.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an electrical connector according to an embodiment.
FIG. 2 is a front view of the electrical connector seen in the direction of an arrow A in FIG. 1.
FIG. 3 is a sectional view of the electrical connector taken along line III-III in FIG. 2.
FIG. 4 is a sectional view of a plug connector illustrated in FIG. 3.
FIG. 5 is a sectional view of a socket connector illustrated in FIG. 3.
FIG. 6 is a sectional view of the socket connector taken along line VI-VI in FIG. 5.
FIG. 7 is an enlarged view of a region R in FIG. 5.
FIG. 8 is a perspective view of the socket connector illustrated in FIG. 6.
FIG. 9 is an enlarged view of a region S in FIG. 8.
FIG. 10 is an enlarged view of a region T in FIG. 5.
FIG. 11 illustrates a socket terminal of FIG. 3 in a displaced state.
FIG. 12 is a front view of a socket terminal according to a modification.
FIG. 13 is a front view of a socket terminal according to a modification.



DESCRIPTION OF THE PREFERRED EMBODIMENTS
Hereinafter, an embodiment of an electrical connector according to the present invention will be described with reference to the drawings. In the embodiment below, an example of an interboard connector having a floating function will be described.
As illustrated in FIGS. 1 and 2, an electrical connector 1 includes a plug connector 2 and a socket connector 3. As illustrated in FIGS. 2 to 5, the plug connector 2 is mounted on a board 4, and the socket connector 3 is mounted on a board 5. When the plug connector 2 is fitted into the socket connector 3, the board 4 and the board 5 become conductively connected to each other.
As illustrated in FIGS. 1 to 13, in the specification, claims, and the drawings, the longitudinal direction of the electrical connector 1 will be referred to as the X direction, the transverse direction of the electrical connector 1 will be referred to as the Y direction, and the insertion/extraction direction in which the plug connector 2 is inserted into/extracted from the socket connector 3 will be referred to as the Z direction. The plug connector 2 side in the insertion/extraction direction Z will be referred to as the “upper side”, and the socket connector 3 side in the insertion/extraction direction Z will be referred to as the “lower side”.
Plug Connector
As illustrated in FIGS. 3 and 4, the plug connector 2 includes a plug housing 6 and plug terminals 7.
Plug Housing
The plug housing 6 is made of an insulating resin and includes a body 6A and legs 6B. The legs 6B are disposed on both sides of the body 6A in the longitudinal direction X of the body 6A and are fixed to the board 4.
The body 6A includes a fitting portion 6a, a separation wall portion 6b, and a base 6c. The fitting portion 6a allows the socket connector 3 to be inserted thereinto when the electrical connector 1 becomes connected. The separation wall portion 6b separates the fitting portion 6a from the base 6c. In a connected state, the base 6c is located near the board 4.
Side walls 6a1, which extend in the longitudinal direction X, are disposed on both sides of the fitting portion 6a in the transverse direction Y (see FIG. 4). A center wall 6a2, which extends in the longitudinal direction X, is disposed between the side walls 6a1. Attachment grooves 6a3 are formed in the center wall 6a2 so as to be arranged side by side in the longitudinal direction X. Each of the plug terminals 7 is pressed into and held by a corresponding one of the attachment grooves 6a3.
Attachment holes 6b1, which are continuous with the attachment grooves 6a3, are formed in the separation wall portion 6b. Each of the plug terminals 7 is inserted into and held by a corresponding one of the attachment holes 6b1.
Side walls 6c1, which extend in the longitudinal direction X, are disposed on both sides of the base 6c in the transverse direction Y (see FIG. 4). Attachment grooves 6c2, which are continuous with the attachment grooves 6a3 and the attachment holes 6b1, are formed in inner surfaces of the side walls 6c1. The plug terminals 7 are held by the attachment grooves 6a3, the attachment holes 6b1, and the attachment groove 6c2, which serve as a terminal attachment portion of the plug housing 6. The base 6c includes bottom portions 6c3, which face the board 4. The bottom portions 6c3 are recessed so as to be separated from a board surface of the board 4 when the legs 6B of the plug housing 6 are fixed to the board 4. The plug terminals 7 are exposed from the bottom portions 6c3 and fixed to the board 4.
Plug Terminal
The plug terminals 7 are made by press-punching and bending a flat metal plate. As illustrated in FIG. 4, each of the plug terminals 7 includes a board connection portion 7a, a first separation portion 7b, a linear portion 7c, a second separation portion 7d, an insertion portion 7e, and a contact portion 7f. 
The board connection portion 7a includes a connection portion 7a1 and a support portion 7a2. The connection portion 7a1, which extends parallel to the board surface, is soldered to the board 4. The support portion 7a2, which is continuous with an end of the connection portion 7a1, is bent so as to extend perpendicularly from the board surface.
The first separation portion 7b is bent so as to extend from an end of the support portion 7a2 parallelly to the board surface. The first separation portion 7b is separated from the bottom portion 6c3 of the plug housing 6 so that a gap is formed between the first separation portion 7b and the bottom portion 6c3. As described below, the gap serves to suppress flowing of flux due to capillary action.
The linear portion 7c extends in the insertion/extraction direction Z of the plug connector 2 and is fixed to the inside of a corresponding one of the attachment grooves 6c2 of the base 6c of the plug housing 6.
The second separation portion 7d extends from an end of the linear portion 7c in a crank shape so as not to be in contact with inner walls of the base 6c and the separation wall portion 6b. The second separation portion 7d is separated from the inner walls of the base 6c and the separation wall portion 6b so that a gap is formed between the second separation portion 7d and the inner walls. As in the case of the first separation portion 7b, the gap serves to suppress flowing of flux due to capillary action.
The insertion portion 7e is inserted into and held by a corresponding one of the attachment holes 6b1 of the separation wall portion 6b of the plug housing 6.
The contact portion 7f, which is to be conductively connected to a corresponding one of socket terminals 9, is disposed in a corresponding one of the attachment grooves 6a3 of the center wall 6a2 of the fitting portion 6a. 
Socket Connector
As illustrated in FIGS. 3 and 5, the socket connector 3 includes a socket housing 8 and the socket terminal 9.
Socket Housing
The socket housing 8 includes a fixed housing 8a and a movable housing 8b. 
Movable Housing
The movable housing 8b, which has a structure as described below, includes a fitting portion 8c and a terminal holding portion 8d, which are arranged in this order in a direction from which the plug connector 2 is inserted. The plug housing 6 is fitted into the fitting portion 8c. The terminal holding portion 8d holds the socket terminals 9.
Long-side walls 8c1, which extend in the longitudinal direction X of the movable housing 8b, are disposed on both sides of the fitting portion 8c in the transverse direction Y. Short-side walls 8c2, which extend in the transverse direction Y, are disposed on both sides of the fitting portion 8c in the longitudinal direction X. Long inner walls 8c3, each of which faces a corresponding one of the long-side walls 8c1, are disposed in the fitting portion 8c. Partition walls 8c4, each of which insulates adjacent socket terminals 9 from each other, are disposed between the long-side walls 8c1 and the long inner walls 8c3 (see FIG. 5). A front wall 8c5 is formed at an end of the fitting portion 8c on the fitting side.
A space between the long inner walls 8c3, which face each other, is a plug insertion portion 8c6 into which the center wall 6a2 of the plug housing 6 is inserted (see FIG. 5).
The socket terminals 9 are disposed in containing portions, which are inner spaces defined by the long-side walls 8c1, the short-side walls 8c2, the long inner walls 8c3, the partition walls 8c4, and the front wall 8c5. In the fitting portion 8c according to the present embodiment, the containing portions are formed on both sides of the plug insertion portion 8c6.
The terminal holding portion 8d includes long-side walls 8d1 and short-side walls 8d2, which are respectively continuous with the long-side walls 8c1 and the short-side walls 8c2 of the fitting portion 8c. The long-side walls 8d1 protrude outward and each has a thickness smaller than that of each of the long-side walls 8c1 of the fitting portion 8c. The terminal holding portion 8d further includes a center wall 8d3 disposed between the long-side walls 8d1. The center wall 8d3 extends from the plug insertion portion 8c6. The center wall 8d3 extends in the insertion/extraction direction Z beyond the lower ends of the long-side walls 8d1 toward the board 5.
Partition walls 8d4, each of which is continuous with a corresponding one of the partition walls 8c4 of the fitting portion 8c, are formed between the long-side walls 8d1 and the center wall 8d3 (see FIG. 5). Thus, adjacent socket terminals 9 are structurally insulated from each other. According to the present embodiment, on the long-side wall 8d1 side of the movable housing 8b, the position of the lower end of the partition wall 8d4 coincides with the position of the lower end of the long-side wall 8d1; on the center wall 8d3 side, the positon of the lower end of the partition wall 8d4 coincides with the position of the lower end of the center wall 8d3.
The socket terminals 9 are disposed in containing portions, which are inner spaces defined by the long-side walls 8d1, the short-side walls 8d2, the center wall 8d3, and the partition walls 8d4. The term “terminal attachment grooves” refer to slit-like grooves formed by the containing portions of the terminal holding portion 8d and the containing portions of the fitting portion 8c. Each of the socket terminals 9 is inserted into and fixed to a corresponding one of the terminal attachment grooves.
As described above, each of the long-side walls 8d1 of the terminal holding portion 8d is formed so as to have a thickness smaller than that of each of the long-side walls 8c1 of the fitting portion 8c. One reason for this is increase the rigidity of the terminal holding portion 8d and to enable the terminal holding portion 8d to securely hold the socket terminal 9 when the socket terminal 9 is pressed into the terminal holding portion 8d. Another reason for this is to make the long-side walls 8d1 extend over a movable portion 11 of the socket terminal 9 and to enable the terminal holding portion 8d to function as a “protective wall” that protects the upper side of the movable portion 11 from a contact or an impact from the outside. In consideration of the function as a protective wall, as illustrated in FIG. 5, the long-side wall 8d1 has a thickness that allows the long-side wall 8d1 to extend over and beyond a first extension 11a of the movable portion 11 in the transverse direction Y when the long-side wall 8d1 is at rest and is not relatively displaced.
As illustrated in FIG. 6, the short-side wall 8d2 of the terminal holding portion 8d includes engagement portions 8d5 extending toward the board 5 and bent outward so as to be parallel to the board surface. As described below, the engagement portions 8d5 function as a stopper for restricting excessive displacement of the movable housing 8b relative to the fixed housing 8a. 
Fixed Housing
The fixed housing 8a is disposed so as to surround the outer periphery of a lower part of the movable housing 8b. The fixed housing 8a has long-side walls 8a1 and short-side wall 8a2. The long-side walls 8a1, which extend in the longitudinal direction X, are disposed on both sides of the fixed housing 8a. The short-side walls 8a2, which extend in the transverse direction Y, are disposed at both ends of the long-side walls 8a1. Fixing holes 8a3, to which the socket terminal 9 are fixed, are formed in the long-side walls 8a1. Each of the short-side walls 8a2 includes legs 8a4 and an engagement receiving portion 8a5. The legs 8a4 are fixed to the board 5. The engagement portions 8d5 described above, which function as a stopper of the movable housing 8b, become engaged with the engagement receiving portions 8a5, each of which is shaped like a hole, in the extraction direction of the insertion/extraction direction Z.
A movable space 14, in which the socket terminal 9 and the movable housing 8b are movable, is formed in the fixed housing 8a having the structure describe above. Structural elements of the movable housing 8b located in the movable space 14 are the center wall 8d3 and the partition walls 8d4 of the terminal holding portion 8d. The widths of the center wall 8d3 and the partition walls 8d4 are smaller than the distance between the outer surfaces of the pair of long-side walls 8d1 in the transverse direction Y. Accordingly, the width of the space occupied by the movable housing 8b in the fixed housing 8a in the transverse direction Y can be reduced and the volume of the movable space 14 can be increased.
An opening 15 is formed between an upper end of each of the long-side walls 8a1 of the fixed housing 8a and a lower end of a corresponding one of the long-side walls 8d1 of the movable housing 8b. The lower end of each of the long-side walls 8d1 of the movable housing 8b are not located inside the fixed housing 8a but is located diagonally above the upper end of a corresponding one of the long-side walls 8a1. Thus, the openings 15 each having a large size are formed, and therefore heat generated on the board 5 and accumulated in the fixed housing 8a can be released to the outside through the openings 15.
Socket Terminal
The socket terminals 9 are made by press-punching a flat metal plate and performing a predetermined finishing operation, such as chamfering, on the punched metal plate. The socket terminals 9 are so-called “punched terminals”, which maintain the shape of a flat metal plate and which are not bent in the thickness direction. The socket terminals 9 are disposed in such a way that the plate surfaces thereof extend in the transverse direction Y of the socket housing 8 and each pair of the socket terminals 9 face each other. As illustrated in FIGS. 3 and 5, each of the socket terminals 9 includes a terminal portion 10, a base 12, the movable portion 11, and a board connection portion 13, which are disposed in this order from the direction from which the plug connector 2 is inserted.
The socket terminals 9 are arranged side by side at a regular pitch in the longitudinal direction X of the socket housing 8. By forming each of the socket terminals 9 in a flat plate-like shape so as not to be bent in the thickness direction, the width of the socket terminal 9 in the longitudinal direction X can be reduced. Therefore, the socket terminals 9 can be arranged at a small pitch, and the size of the electrical connector 1 in the longitudinal direction X can be reduced. As a result, the size of the electrical connector 1 according to the present embodiment can be reduced also in the transverse direction Y as described below.
Board Connection Portion
Each of the board connection portions 13 includes a connection portion 13a, a support portion 13b, and a fixing piece 13c. The connection portion 13a protrudes outward from the fixed housing 8a and is soldered to the board 5. The support portions 13b are disposed on the upper side of the connection portion 13a and support the socket housing 8 at a position above the board surface of the board 5. When the board connection portions 13 have been soldered, a gap is formed between the support portion 13b and the board 5. The fixing piece 13c is formed on each of the support portion 13b so as to protrude in the insertion/extraction direction Z. When engagement protrusions 13d of the fixing pieces 13c engage with inner walls of the fixing holes 8a3 of the fixed housing 8a, the socket terminals 9 are fixed to the fixed housing 8a. 
Movable Portion
The movable portion 11 is a strip-shaped elastic member that is inversely U-shaped. The movable portion includes the first extension 11a, a hairpin portion 11b, and a second extension 11c. The first extension 11a, the second extension 11c, and a lower portion 12b of the base 12 (described below) are disposed side by side. The movable portion 11 is located in the movable space 14 in the fixed housing 8a and elastically supports the movable housing 8b so as to be movable relative to the fixed housing 8a. 
By providing the movable portion 11, for example, when the electrical connector 1 is vibrated or when the plug connector 2 is being fitted into the socket connector 3, the movable portion 11 becomes displaced in the movable space 14 and the movable housing 8b can be displaced relative to the fixed housing 8a. 
The first extension 11a extends in the insertion/extraction direction Z from an end of the board connection portion 13 in the horizontal direction. The first extension 11a is separated from the board connection portion 13 with a gap-forming portion 14c interposed between the first extension 11a and an inner surface 8a6 of the fixed housing 8a (see FIG. 10). Thus, even if flux flows up along the board connection portion 13 and reaches the movable portion 11, because the gap-forming portion 14c is present near the boundary between the movable portion 11 and the board connection portion 13 and the movable portion 11 is separated from the inner surface 8a6, flowing up of flux due to capillary action, which might occur if the first extension 11a were in contact the inner surface 8a6, can be suppressed. The hairpin portion 11b is disposed at the upper end of the first extension 11a so as to be continuous with the second extension 11c. 
As illustrated in FIG. 10, the second extension 11c extends substantially parallel to the first extension 11a. The second extension 11c is bent at a lower end thereof and connected to the base 12. The second extension 11c includes a spring portion 11d that is bent in a crank shape. Because the spring portion 11d is formed in the middle of the second extension 11c, the distance between the base and a gap-forming portion 11f above the spring portion 11d is larger than the distance between the base 12 and a gap-forming portion 11e below the spring portion 11d. In other words, a first movable space 14a, which is wide, is formed between the base 12 and the gap-forming portion 11f near the hairpin portion 11b; and a second movable space 14b, which is narrower than the first movable space 14a, is formed between the base 12 and the gap-forming portion 11e continuous with the base 12.
Base
As illustrated in FIGS. 3 and 5, the base 12 includes an upper portion 12a, which has a large width, and the lower portion 12b, which has a narrow strip-like shape. The upper portion 12a is held between the center wall 8d3 and the long-side wall 8d1 of the terminal holding portion 8d of the movable housing 8b. An upper end of the upper portion 12a is continuous with the terminal portion 10. The lower portion 12b, which has a narrow strip-like shape, protrudes to a positon below the long-side wall 8d1. A lower end of the lower portion 12b is continuous with the second extension 11c of the movable portion 11.
A recessed cutout portion 12c is formed along an edge of the lower portion 12b (of the base 12) facing the second extension 11c. Because the cutout portion 12c is formed, the width of the lower portion 12b in the transverse direction Y is about a half of the width of the upper portion 12a. The cutout portion 12c is defined by a vertical edge 12d, which extends in the insertion/extraction direction Z, and a horizontal edge 12e, which extends in the transverse direction Y. The second extension 11c is disposed in the recess formed by the cutout portion 12c. Thus, the width of the socket terminal 9 in the transverse direction Y can be reduced, and the socket connector 3 can be reduced in size. The horizontal edge 12e of the cutout portion 12c is substantially flush with the lower end surface of the long-side wall 8d1 of the movable housing 8b, which has a large thickness, and therefore heat can be smoothly dissipated from the inside of the movable space 14 through the opening 15.
An engagement portion 12a1 is formed in the upper portion 12a. When the engagement portion 12a1 engages with the center wall 8d3 of the movable housing 8b, the socket terminal 9 is fixed to the movable housing 8b. A pressure receiving portion 12b1 is formed at an end of the lower portion 12b near the board. When assembling the socket connector 3, the socket terminal 9 is pressed into the movable housing 8b by pressing the pressure receiving portion 12b1.
Terminal Portion
As illustrated in FIGS. 5 and 7, the terminal portion 10 includes a front terminal 16 and a rear terminal 17, each extending from the upper end of the base 12 like a cantilever.
Front Terminal
The front terminal 16 includes an elastic piece 16a and a contact portion 16b. The elastic piece 16a protrudes upward from the upper end of the base 12. The contact portion 16b is disposed at an end of the elastic piece 16a and protrudes in a direction from which the plug terminal 7 comes into contact. In a connected state, a front contact-point portion 16c at an end of the contact portion 16b contacts the plug terminal 7. The contact portion 16b includes a front edge 16d above the front contact-point portion 16c. The front edge 16d has a function of removing foreign substances adhering to the contact portion 7f of the plug terminal 7.
A recessed portion 16e is formed in a part of an edge of an end portion of the elastic piece 16a facing a contact portion 17b of the rear terminal 17. The width of the elastic piece 16a is partially reduced at the recessed portion 16e. When the plug connector 2 is fitted into the socket connector 3 and the plug terminal 7 presses the rear terminal 17 toward the front terminal 16, the end portion of the rear terminal 17 is moved into the recessed portion 16e. Therefore, the rear terminal 17 does not easily contact the front terminal 16.
Rear Terminal
The rear terminal 17 includes an elastic piece 17a and the contact portion 17b. The elastic piece 17a extends from an upper end of the base 12. The contact portion 17b is disposed at an end of the elastic piece 17a and protrudes in a direction from which the plug terminal 7 comes into contact. In a connected state, a rear contact-point portion 17c at an end of the contact portion 17b contacts with the plug terminal 7. The rear contact-point portion 17c is located deeper in the insertion/extraction direction Z than the front contact-point portion 16c. When the plug connector 2 is inserted into the socket connector 3, the plug terminal 7 first contacts the front terminal 16 and then contacts the rear terminal 17.
When the plug connector 2 has been connected, a protruding amount by which the rear contact-point portion 17c protrudes from the long inner wall 8c3 is larger than that of the front contact-point portion 16c. Thus, when the plug connector 2 is being connected and the plug terminal 7 presses the rear contact-point portion 17c and the front contact-point portion 16c, the amount of displacement of the rear contact-point portion 17c toward the long-side wall 8c1 is larger than the amount of displacement of the front contact-point portion 16c toward the long-side wall 8c1. In general, provided that the spring constant is the same, the contact pressure increases as the amount of displacement of the terminal increases. Accordingly, because the front contact-point portion 16c and the rear contact-point portion 17c are disposed as described above, the contact pressure of the rear terminal 17 is larger than that of the front terminal 16. Thus, the rear contact-point portion 17c, which is located deeper in the insertion/extraction direction Z than the front contact-point portion 16c, can conductively contact the plug terminal 7 securely.
The terminal portion 10 includes two contact-point portions, which are the front contact-point portion 16c and the rear contact-point portion 17c. Thus, even if a foreign substance, such as dust, enters a space between the contact portion 7f and one of the front and rear contact-point portions 16c and 17c, the other of the front and rear contact-point portions 16c and 17c can contact the plug terminal 7. As a result, the contact reliability can be increased.
Description of Operational Effects of Electrical Connector
Next, the operational effects of the electrical connector 1 according to the present embodiment will be described.
Reduction in Size of Electrical Connector
The socket terminals 9 each have a flat plate-like shape, which maintains the shape of a flat metal plate and which is not bent in the thickness direction. Therefore, a large number of socket terminals 9 can be arranged at a small pitch, and the socket connector 3 and the electrical connector 1, which are compact in the longitudinal direction X, can be realized.
In the base 12 of the socket terminal 9, the upper portion 12a, which is continuous with the terminal portion 10, has a large width in the transverse direction Y. This is because the terminal portion 10 has a multi-terminal multi-contact structure, including the front terminal 16 and the rear terminal 17, in order to obtain the advantages described above. For the terminal portion 10 of this type, it may be possible to form the lower portion 12b by extending the upper portion 12a in a direction toward the board so as to maintain the width of the upper portion 12a. In the present embodiment, however, the width of the lower portion 12b is reduced by forming the cutout portion 12c, and the second extension 11c and substantially a half of the hairpin portion 11b of the movable portion 11 are disposed in the recess formed by the cutout portion 12c. Thus, as compared with a case where the upper portion 12a and the lower portion 12b have the same width and the movable portion 11 is disposed so as to be parallel to the lower portion 12b, the size of the socket terminal 9 can be reduced in the transverse direction Y and the sizes of the socket connector 3 and the electrical connector 1 can be reduced. As a result, according to the present embodiment, the size of the electrical connector 1 having a floating structure can be reduced in both of the longitudinal direction X and the transverse direction Y. Furthermore, the electrical connector 1 can contribute to reduction in the size of electronic appliances and to high-density mounting of electronic components.
In the electrical connector 1, the movable portion 11 and the lower portion 12b of the base 12 are arranged side by side below the terminal portion 10. In some cases, the board 4 and the board 5 may need to be separated from each other by a considerable distance, depending on the types of components mounted thereon and the constraints on the design of various electronic appliances. In such cases, the electrical connector 1 according to the present embodiment can have a large height in the insertion/extraction direction Z while reducing the sizes in the longitudinal direction X and the transverse direction Y, because the terminal portion 10, the movable portion 11, and the lower portion 12b of the base 12 of the socket terminal 9 are vertically and serially arranged in the insertion/extraction direction Z.
When the plug connector 2 is being fitted into the socket connector 3, the plug terminal 7 presses the front terminal 16 and the rear terminal 17 outward. In order to prevent the rear terminal 17 from contacting the front terminal 16 at this time, it may be necessary that the rear terminal 17 be separated from the front terminal 16 by a large distance. However, in the electrical connector 1 according to the present embodiment, the recessed portion 16e is formed in the edge of the elastic piece 16a of the front terminal 16 facing the rear terminal 17. Thus, when the rear terminal 17 is pressed by the plug terminal 7, the contact portion 17b of the rear terminal 17 enters the recessed portion 16e, and therefore the front terminal 16 can be prevented from contacting the elastic piece 16a. Accordingly, even when the front terminal 16 is disposed close to the rear terminal 17 to reduce the width of the upper portion 12a of the base 12 in the transverse direction Y, a sufficient space in which the rear terminal 17 is movable can be formed between the front terminal 16 and the rear terminal 17. Therefore, the size of the socket terminal 9 can be reduced in the transverse direction Y.
In the present embodiment, for reasons of design and manufacturing, the distance between each pair of the front contact-point portions 16c that face each other is smaller than the distance between each pair of the rear contact-point portions 17c that face each other and the protruding amount by which the rear contact-point portion 17c protrudes from the long inner wall 8c3 of the movable housing 8b is larger than that of the front contact-point portion 16c. Accordingly, when the plug connector 2 is connected, an amount of displacement of the rear terminal 17 is larger than that of the front terminal 16. Therefore, in a connected state, the rear terminal 17 is located considerably close to the front terminal 16. However, because the front terminal 16 has the recessed portion 16e as described above, the size of the electrical connector 1 can be reduced in the transverse direction Y while avoiding contact between the rear terminal 17 and the front terminal 16.
The movable portion 11 includes the crank-shaped spring portion 11d. If the crank-shaped spring portion 11d were not provided, when the movable housing 8b becomes displaced toward the fixed housing 8a, an upper part of the second extension 11c might contact the base 12 or a lower part of the first extension 11a might contact a lower part of the second extension 11c. To prevent such contact, it would be necessary that the distance between the second extension 11c and the base 12 and the distance between the first extension 11a and the second extension 11c be large enough to avoid contact. In this case, however, the size of the socket terminal 9 in the transverse direction Y would be increased. For this reason, the crank-shaped spring portion 11d if formed in the movable portion 11, so that the first movable space 14a having a large size is formed between the base 12 and a part (the gap-forming portion 11f) of the second extension 11c near the hairpin portion 11b. Thus, the second extension 11c does not contact the base 12 when the movable housing 8b becomes displaced so as to approach the fixed housing 8a (see FIGS. 10 and 11). Moreover, although the second movable space 14b, which is narrow, is formed between the base 12 and a part (the gap-forming portion 11e) of the second extension 11c below the spring portion 11d, a third movable space 14d, which is wide, is formed between the gap-forming portion 11e and a part of the first extension 11a opposite to the base 12 and near the board. Accordingly, even when the movable housing 8b becomes displaced toward the fixed housing 8a, a part of the second extension 11c near the board (the gap-forming portion 11e) does not contact a part of the first extension 11a near the board (see FIG. 11).
Structure for Suppressing Flowing-Up of Flux
Because the plug terminals 7 include the support portions 7a2, the plug housing 6 is located above the board 4 when the plug housing 6 is mounted on the board 4. Thus, flux does not easily adhere to the plug housing 6, and the flux can be prevented from flowing along the plug housing 6 and from entering gaps between the plug housing 6 and the plug terminals 7. Moreover, because the plug terminals 7 include the first separation portions 7b and the second separation portions 7d, even if flux adheres to the plug housing 6, the first separation portion 7b or the second separation portion 7d can prevent the flux from flowing up through gaps between the plug housing 6 and the plug terminals 7 due to capillary action.
Because the socket terminals 9 include the support portions 13b, the fixed housing 8a is located above the board 5 when the socket terminal 9 is mounted on the board 5. Accordingly, flux does not easily adhere to the fixed housing 8a, and the flux is prevented from flowing along the fixed housing 8a and from flowing into gaps between the fixed housing 8a and the socket terminals 9. Even if flux flows into the gaps, the gap-forming portion 14c, which is disposed between the fixed housing 8a and the first extension 11a of the movable portion 11, can prevent the flux from flowing up due to capillary action. Because flowing up of flux can be prevented as described above, it is possible to suppress poor connection between terminals, which may occur due to flow of flux to the contact portion 7f of the plug terminal 7 and to the terminal portion 10 of the socket terminal 9.
Improvement of Insertability Due to Displaced Contact-Point Structure
As illustrated in FIGS. 6 to 9, in the socket connector 3, the socket terminals 9 are arranged side by side in the longitudinal direction X. As illustrated in FIG. 9, the front contact-point portions 16c of adjacent socket terminals 9 are disposed so as to be displaced from each other by a distance H1 in the insertion/extraction direction Z. Likewise, the rear contact-point portions 17c of adjacent socket terminals 9 are disposed so as to be displaced from each other by a distance H2 in the insertion/extraction direction Z. When the plug connector 2, which is a connection object, is fitted into the socket connector 3, the end of the plug terminal 7 first presses the contact portion 16b of the front terminal 16 to displace the contact portion 16b to an outer side of the socket housing 8 and to cause the contact portion 16b to pass over the front contact-point portion 16c. Subsequently, the end of the plug terminal 7 presses the contact portion 17b of the rear terminal 17 to displace the contact portion 17b in the same way and to cause the contact portion 17b to pass over the rear contact-point portion 17c. Thus, the front contact-point portion 16c and the rear contact-point portion 17c come into contact with the contact portion 7f of the plug terminal 7, thereby finishing connection of the plug connector 2 and the socket connector 3.
When an operator (not shown) presses the contact portion 16b of the front terminal 16 and the contact portion 17b of the rear terminal 17, the operator receives a resistance from the plurality of socket terminals 9 of the socket connector 3. Therefore, the operator has to apply a large force to fit the plug connector 2 into the socket connector 3. Moreover, when the end of the plug terminal 7 passes over the front contact-point portion 16c and when the end of the plug terminal 7 passes over the rear contact-point portion 17c, the operator feels a resistance with his/her hand. Accordingly, the operator may misunderstand that the plug connector 2 has been fitted into the socket connector 3 when the end of the plug terminal 7 has passed over the front contact-point portion 16c and may stop inserting the plug connector 2 in a semi-fitted state. Moreover, if the operator tries to forcibly insert the plug connector 2 into the socket connector 3 with a large force, the plug connector 2 may become obliquely fitted into the socket connector 3 or the socket terminal 9 may become buckled and damaged.
For this reason, with the electrical connector 1 according to the present embodiment, the plug terminals 7 come into contact with the socket terminals 9 at different timings, because adjacent front contact-point portions 16c are displaced from each other and adjacent rear contact-point portions 17c are displaced from each other in the insertion/extraction direction Z. Thus, the number of the socket terminals 9 that simultaneously contact the plug terminals 7 can be reduced, and the insertion force can be dispersed. Accordingly, an operator can fit the plug connector 2 into the socket connector 3 with a smaller force, so that occurrences of semi-fitting, oblique fitting, buckling, and the like can be suppressed.
Function of Removing Foreign Substance
When the plug connector 2 has been fitted into the socket connector 3, the plug terminal 7 comes into contact with and becomes conductively connected to the socket terminal 9. Foreign substances, such as fragments of the board or dust, may adhere to the contact portion 7f of the plug terminal 7. If the rear contact-point portion 17c contacts the contact portion 7f of the plug terminal 7 in such a state, the foreign substances may be interposed between the rear contact-point portion 17c and the contact portion 7f of the plug terminal 7. In this case, conductive connection between the rear contact-point portion 17c and the plug terminal 7 might become unstable. However, as illustrated in FIGS. 3, 5, and 7, the front contact-point portion 16c is disposed above the rear contact-point portion 17c, and, when the plug connector 2 is fitted into the socket connector 3, the front contact-point portion 16c and the rear contact-point portion 17c successively and slidably contact the contact portion 7f of the plug terminal 7. Thus, the front contact-point portion 16c and the front edge 16d thereof can wipe off foreign substances adhering to the contact portion 7f of the plug terminal 7. Moreover, the rear contact-point portion 17c contact parts of the contact portion 7f of the plug terminal 7 from which foreign substances have been wiped off, and therefore the rear contact-point portion 17c can be conductively connected to the plug terminal 7 with no foreign substances interposed therebetween. As a result, the contact reliability can be increased.
The electrical connector 1 according to the present embodiment has a small size in the transverse direction Y even though the electrical connector 1 includes the movable portion 11. Thus, by using the electrical connector 1, it is possible to realize reduction in the sizes of electrical appliances and high-density mounting of electronic components. By using the electrical connector 1 according to the present embodiment, occurrence of defective contact, which is caused by flowing up of flux and adhesion of flux to the terminal portion 10, can be reduced. Moreover, because the contact pressure of the rear terminal 17 is higher than that of the front terminal 16, the rear terminal 17 can securely contact the plug terminal 7. Furthermore, by displacing the positions of adjacent front contact-point portions 16c from each other or by displacing the positions of adjacent rear contact-point portions 17c from each other, the insertability of the electrical connector 1 can be improved. As a result, the electrical connector 1 has high contact reliability.
Modifications of the Embodiment
In the embodiment described above, the electrical connector 1 includes the front terminal 16 and the rear terminal 17. However, the electrical connector 1 may include only one elastic piece or only one contact-point portion, or one elastic piece may elastically support a plurality of contact-point portions. In any of these cases, the electrical connector 1 can be reduced in size in the transverse direction Y.
In the embodiment described above, the electrical connector 1 has two contact point portions, which are the front contact-point portion 16c and the rear contact-point portion 17c. Alternatively, the electrical connector 1 may have only one contact-point portion.
In the movable portion 11 according to the embodiment described above, the second extension 11c is disposed in the recess formed by the cutout portion 12c and the first extension 11a is disposed outside the cutout portion 12c. Alternatively, the first extension 11a may be also disposed in the cutout portion 12c. In this case, the electrical connector 1 can be made compact in the transverse direction Y.
In the embodiment described above, the horizontal edge 12e of the cutout portion 12c is flush with a lower end surface of the long-side wall 8d1 of the movable housing 8b. Alternatively, the lower end surface may be disposed above the horizontal edge 12e. In this case, the openings 15 are made larger and heat can be dissipated more efficiently.
In the embodiment described above, the second extension 11c includes the spring portion 11d. Alternatively, the spring portion 11d may be omitted, and the second extension 11c may be formed so as to become separated from the lower portion 12b of the base 12 with increasing distance from one end thereof near the base 12 to the other end thereof near the hairpin portion 11b (see FIG. 12). The second extension 11c may extend in the insertion/extraction direction Z, and the vertical edge 12d of the cutout portion 12c may be formed so as to become nearer to the center wall 8d3 from a lower part thereof toward an upper part thereof. For example, the vertical edge 12d of the cutout portion 12c may be inclined toward the center wall 8d3 from the lower part toward the upper part or may have a stepped shape (see FIG. 13). Also in these cases, the width of a gap between the second extension 11c and the cutout portion 12c at an upper end portion near the hairpin portion 11b can be made larger than that at a lower end portion that is continuous with the base 12.
In the embodiment described above, the contact pressure of the rear terminal 17 is higher than that of the front terminal 16. Alternatively, the contact pressure of the front terminal 16 may be higher than that of the rear terminal 17. In this case, the front contact-point portion 16c can be made to securely contact the plug terminal 7. Further alternatively, the contact pressure of the front terminal 16 may be substantially the same as that of the rear terminal 17.
In the embodiment described above, adjacent front contact-point portions 16c and adjacent rear contact-point portions 17c are respectively displaced from each other in the insertion/extraction direction Z. Alternatively, for example, sets of front contact-point portions 16c that are disposed adjacent to each other in the longitudinal direction X or sets of rear contact-point portions 17c that are disposed adjacent to each other in the longitudinal direction X may be respectively displaced from each other in the insertion/extraction direction Z. In this case, by disposing sets of, for example, three contact-point portions so as to be displaced from each other, concentration of resistance on specific positions can be avoided and an operation of connecting the connectors can be performed easily.
In the embodiment described above, the plug connector 2 is used an example of a connection object that is connected to the socket connector 3. Alternatively, the connection object may be any one of connectors, boards (hard boards and FPCs), cables (flexible flat cables and the like), as long as it can successively contact the front terminal 16 and the rear terminal 17 of the socket terminal 9 in the insertion direction and can be conductively connected to the front terminal 16 and the rear terminal 17. In this case, the structure of the socket connector 3 may be changed appropriately in accordance with the structure of the connection object.

## Claims

1. A connector terminal comprising:
a movable portion that elastically supports a movable housing in such a way that the movable housing is displaceable relative to a fixed housing that is fixed to a board, and
a base that is attached to the movable housing and that is continuous with the movable portion,
wherein the movable portion includes
a first extension located near the fixed housing,
a hairpin portion, and
a second extension located near the movable housing and adjacent to the base,

wherein the first extension, the second extension, and the base are arranged side by side, and
wherein a width of a gap between the second extension and the base at one end portion of the second extension continuous with the hairpin portion is larger than that at the other end portion of the second extension continuous with the base.

2. The connector terminal according to claim 1,
wherein the second extension is inclined in such a way that the width of the gap between the second extension and the base increases from the other end portion toward the one end portion.

3. The connector terminal according to claim 1,
wherein the second extension includes a spring portion that is bent in such away that the width of the gap between the second extension and the base near the one end portion is larger than that near the other end portion.

4. The connector terminal according to claim 1,
wherein the base has a vertical edge that is shaped in such way that the width of the gap between the second extension and the base near the one end portion is larger than that near the other end portion.

5. An electrical connector comprising:
the connector terminal according to claim 1.