Electrical Connector Capable of Avoiding Incomplete Connection of a Connection Member

This invention relates to an electrical connector for connecting a flat connection member such as a flexible flat cable (FFC) and a flexible printed circuit (FPC) to a connection object such as a printed circuit board (PCB).

A first conventional electrical connector of the type is disclosed in Japanese Unexamined Utility Model Publication (JP-U) No. 6-77186 (77186/1994). The first conventional electrical connector comprises an insulator housing having a base, a plurality of contacts fixed to the housing and having contact portions exposed above the base, and a pressing member rotatably supported to the housing. A connection member or FPC is at first disposed at a predetermined connecting position on the contact points of the plurality of contacts. Then, the pressing member is rotated to press the FPC against the contact points so that the FPC is connected to the contacts. The contacts are, for example, soldered to a PCB so that the FPC is connected to the PCB.

A second conventional electrical connector of the type is disclosed in Japanese Unexamined Utility Model Publication (JP-U) No. 5-6759 (6759/1993). The second conventional electrical connector comprises an insulator with a receptacle hole formed therein, a plurality of conductive contacts fitted in the receptacle hole, and a slider member. Each of the contacts has a holding portion held by the insulator at a rear side of the receptacle hole, a fixing portion extending from the holding portion towards a front side of the receptacle hole, and a contacting spring portion extending from the holding portion towards the front side of the receptacle hole in parallel to the fixing portion with a space kept therefrom. The contacting spring portion has a contact point formed at its one end to protrude towards the fixing portion.

The slider member has a slider base portion and a pressing portion extending from the slider base portion along the fixing portion to be removably inserted into the receptacle hole.

In the second conventional electrical connector, a connection member is inserted between the fixing portion and the contacting spring portion of each contact until the connection member reaches a predetermined connecting position over the contact points of the contacts. Then, the pressing portion of the slider member is placed on the connection member. Thereafter, the slider member is inserted into the receptacle hole and slides from the front side towards the rear side until the slider member reaches a predetermined slide position. At this time, the pressing portion presses the connection member against the contact points so that a plurality of conductive portions of the connection member are electrically connected to the contact points in press contact therewith.

However, the first conventional electrical connector is disadvantageous in the following respects. Specifically, in case where the connection member is not rightly disposed at the predetermined connecting position and the pressing member is rotated, connection between the connection member and the contact points becomes incomplete.

Even if the connection member is completely inserted to the predetermined connecting position, the connection member may be undesirably released from the insulator due to external force or vibration before the pressing member is rotated to the predetermined pressing position.

On the other hand, the second conventional electrical connector is disadvantageous in the following respects. Specifically, in case where the connection member is not completely inserted to the predetermined connecting position and the slider member slides to the predetermined slide position, connection between the connection member and the contact points becomes incomplete.

In addition, the contacting spring portion is continuously subjected to reactive force from the pressing portion of the slider member so that spring force of the contacting spring portion is gradually decreased. Thus, it is impossible to keep stable and reliable connection over a long period of time.

Even if the connection member is completely inserted to the predetermined connecting position, the connection member may be undesirably released from the insulator due to external force or vibration before the slider member slides to the predetermined slide position.

In both of the first and the second conventional electrical connectors, whether or not the connection member is completely inserted to the predetermined connecting position is confirmed through visual observation by an operator. Such confirmation is difficult and unreliable and often fails to detect incomplete insertion.

In the first conventional electrical connector, the connection member is held or clamped between the contact points of the contacts and the pressing member. In the second conventional electrical connector, the connection member is held or clamped between the contact points and the slider member. In either event, clamping force is weak and the connection member may easily be released from the insulator.

It is an object of this invention to provide an electrical connector capable of detecting incomplete connection of a connecting member.

It is another object of this invention to provide an electrical connector capable of avoiding a connection member from being easily released during a connecting operation.

It is still another object of this invention to provide an electrical connector capable of confirming proper positioning of a connection member by a click feeling.

It is yet another object of this invention to provide an electrical connector capable of increasing clamping force to keep stable connection after a connection member is completely connected.

It is a further object of this invention to provide an electrical connector capable of improving reliability of connection without being affected by variation in shape or deformation of an insulator.

According to this invention, there is provided an electrical connector comprising a single connector unit which includes an insulator (101) having an opening portion (102) for receiving a forward end portion of a flat connection member with a pair of protruding ends formed on both sides of the forward end portion, a plurality of conductive contacts (103) fitted in the opening portion to face to a plurality of conductive portions (135) formed on one surface of the forward end portion of the connection member, and a pressing member (105) rotatably supported on the insulator so that, after the forward end portion of the connection member is inserted into the opening portion in an inserting direction to reach a predetermined connecting position, the pressing member is rotated to a predetermined pressing position to press the forward end portion of the connection member against the contacts so that the conductive portions and the contacts are connected to each other, wherein the pressing member and the insulator are provided with locking means (125, 128) for locking the pressing member to the insulator after the pressing member is rotated to the predetermined pressing position only when the forward end portion of the connection member is properly located at the predetermined connecting position, and detecting means (105d, 119) for inhibiting, when the forward end portion of the connection member is not properly located at the predetermined connecting position, the rotation of the pressing member to detect that the forward end portion of the connection member is not properly located.

According to this invention, there is also provided an electrical connector comprising a plurality of the above-mentioned connector units arranged offset from one another in the inserting direction and stacked in a plurality of stages in a vertical direction.

According to this invention, the insulator (101) has a fitting portion (151) for fitting and connecting a mating connection element. The fitting portion has a plurality of connecting portions (153b) to be connected to a plurality of mating contacts of the mating connection element.

According to this invention, there is also provided an electrical connector comprising a pair of the above-mentioned connector units with their insulators (101) integrally connected to each other at the rear sides. The opening portion (102) and the pressing member (105) of one of the insulators are formed at positions symmetrical with those of the other insulator. The insulators are provided with the contacts symmetrically arranged. Each of the contacts of the one insulator and each corresponding one of the other insulator are coupled back to back at the holding portions through a coupling portion (103y) extending from the holding portions.

FIG. 1 is a sectional view of a first conventional electrical connector with a connection member connected thereto;

FIG. 2 is a sectional view of a second conventional electrical connector with a connection member connected thereto;

FIG. 3 is a perspective view of a contact illustrated in FIG. 2;

FIG. 4 is a perspective view of an electrical connector according to a first embodiment of this invention before a connection member is connected;

FIG. 5 is a sectional view taken along a line V--V in FIG. 4;

FIG. 6 is a sectional view similar to FIG. 5 when the connection member is completely connected;

FIG. 7 is a partially-sectional perspective view for describing a contact illustrated in FIG. 4;

FIG. 8 is a perspective view of the contact illustrated in FIG. 4;

FIG. 9 is a perspective view of the electrical connector in FIG. 4 when the connection member is partly inserted;

FIG. 10 is a perspective view of the electrical

FIG. 10 is a perspective view of the electrical connector in FIG. 4 when the connection member is inserted to a predetermined connecting position;

FIG. 11 is a perspective view of the electrical connector in FIG. 4 when a pressing member is in the middle of rotation;

FIG. 12 is a perspective view of the electrical connector in FIG. 4 when the pressing member is rotated to a predetermined pressing position;

FIG. 13 is a plan view of the electrical connector in FIG. 9;

FIG. 14 is a plan view of the electrical connector in FIG. 10;

FIG. 15 is a perspective view of a modification of the connection member illustrated in FIG. 4;

FIG. 16 is a perspective view of an electrical connector according to a second embodiment of this invention before two connection members are connected;

FIG. 17 is a sectional view taken along a line XVII--XVII in FIG. 16;

FIG. 18 is a sectional view similar to FIG. 17 when the connection members are connected;

FIG. 19 is a sectional view of an electrical connector according to a third embodiment of this invention with a mating connector connected thereto;

FIG. 20 is a partially-sectional perspective view of the electrical connector illustrated in FIG. 19 before a connection member is connected;

FIG. 21 is a sectional view of the electrical connector illustrated in FIG. 19;

FIG. 22 is a sectional view of the electrical connector in FIG. 19 after the connection member is connected;

FIG. 23 is a perspective view of a contact illustrated in FIG. 19;

FIG. 24 is a perspective view similar to FIG. 23 with a part cut away;

FIG. 25 is a development of the contact illustrated in FIG. 19;

FIG. 26 is a partially-sectional perspective view of an electrical connector according to a fourth embodiment of this invention; and

FIG. 27 is a perspective view of a contact illustrated in FIG. 26.

For a better understanding of this invention, description will at first be made about conventional electrical connectors with reference to the drawing.

Referring to FIG. 1, a first conventional electrical connector comprises an insulator 1, a plurality of conductive contacts 3 (only one being illustrated in the figure) fitted to the insulator 1, and a pressing member 7 supported by the insulator 1.

The insulator 1 has a rotation support portion 5. The pressing member 7 is supported by the rotation support portion 5 to be rotatable between a predetermined pressing position closely adjacent to the contacts 3 and an open position apart from the predetermined pressing position. The pressing member 7 has a pressing protrusion 12 for pressing a connection member 11 against the contacts 3 when the pressing member 7 is rotated to the predetermined pressing position after the connection member 11 is located above the contacts 3 as will later be described.

Each of the contacts 3 has a holding portion 3a held by the insulator 1, a fixing portion 3b extending from the holding portion 3b towards an opening side of a receptacle hole la formed in the insulator 1, and a contacting spring portion 3c connected to the fixing portion 3b at the opening side of the receptacle hole la and extending in parallel to the fixing portion 3b. The contacting spring portion 3c has a contact point 3d formed at its one end to be connected to a conductive portion (not shown) of the connection member 11.

In the first conventional electrical connector mentioned above, the connection member 11 is at first inserted to a predetermined connecting position over the contact points 3d of the contacts 3. Then, the pressing member 7 is rotated from the open position to the predetermined pressing position to press the connection member 11 against the contact points 3d so that the connection member 11 is connected to the contact points 3d.

Referring to FIGS. 2 and 3, a second conventional electrical connector comprises an insulator 21 with a receptacle hole 21a formed therein, a plurality of conductive contacts 23 (only one being illustrated in the figure) fitted in the receptacle hole 21a, and an insulating slider member 25 removably coupled to the insulator 21.

Each of the contacts 23 has a holding portion 23a held by the insulator 21 at a rear side of the receptacle hole 21a, a fixing portion 23b extending from the holding portion 23a towards a front side of the receptacle hole 21a, and a contacting spring portion 23c extending from the holding portion 23a towards the front side of the receptacle hole 21a generally in parallel to the fixing portion 23b with a space kept therefrom. The contacting spring portion 23c has a contact point 23d formed at its one end to protrude towards the fixing portion 23b.

The slider member 25 has a slider base portion 25a and a pressing portion 25b extending from the slider base portion 25a along the fixing portion 23b to be removably inserted into the receptacle hole 21a.

In the second conventional electrical connector mentioned above, a connection member 27 is inserted between the fixing portion 23b and the contacting spring portion 23c of each of the contacts 23 until the connection member 27 reaches a predetermined connecting position over the contact points 23d of the contacts 3. Then, the pressing portion 25b of the slider member 25 is placed on the connection member 27. Thereafter, the slider member 25 is inserted into the receptacle hole 21a and slides from the front side towards the rear side until the slider member reaches a predetermined slide position over the contact points 23d. At this time, the pressing portion 25b presses the connection member 27 against the contact points 23d so that a plurality of conductive portions of the connection member 27 are electrically connected to the contact points 23d in press contact therewith.

However, the first conventional electrical connector is disadvantageous in the following respects. Specifically, in case where the connection member 11 is not completely inserted to the predetermined connecting position and the pressing member 7 is rotated to the predetermined pressing position, connection between the connection member 11 and the contact points 13d becomes incomplete.

Even if the connection member 11 is completely inserted to the predetermined connecting position, the connection member 11 may be undesirably released from the insulator 1 due to external force or vibration before the pressing member 7 is rotated to the predetermined pressing position.

On the other hand, the second conventional electrical connector is disadvantageous in the following respects. Specifically, in case where the connection member 27 is not completely inserted to the predetermined connecting position and the slider member 25 slides to the predetermined slide position, connection between the connection member 27 and the contact points 23d becomes incomplete.

In addition, the contacting spring portion 23c is continuously subjected to reactive force from the pressing portion 25b of the slider member 25 so that spring force of the contacting spring portion 23c is gradually decreased. Thus, it is impossible to keep stable and reliable connection over a long period of time.

Even if the connection member 27 is completely inserted to the predetermined connecting position, the connection member 27 may be undesirably released from the insulator 21 due to external force or vibration before the slider member 25 slides to the predetermined slide position.

In each of the first and the second conventional electrical connectors, whether or not the connection member 11 or 27 is completely inserted to the predetermined connecting position is confirmed by visual observation. Such confirmation is difficult and unreliable and often fails to detect incomplete insertion.

In addition, the connection member 11 is held or clamped between the contact points 3d of the contacts 3 and the pressing member 7 in the first conventional electrical connector while the connection member 27 is held or clamped between the contact points 23d of the contacts 23 and the slider member 25 in the second conventional electrical connector. In either event, clamping force is weak and the connection member 11 or 27 may easily be released from the insulator 1 or 21.

Now, description will be made about several preferred embodiments of this invention with reference to the drawing.

Referring to FIGS. 4 and 5, an electrical connector according to a first embodiment of this invention comprises an insulator 101 of a generally box-like shape, a plurality of conductive contacts 103 fitted in the insulator 101, and a pressing member 105 rotatably supported by the insulator 101.

When a connection member 130 is inserted into the insulator 101 in an inserting direction, the pressing member 105 serves to press the connection member 130 to connect the connection member 130 to the contacts 103. The connection member 130 has a pair of notches (locking portions) 133 formed in its forward end portion on both side edges in a widthwise direction perpendicular to the inserting direction. By presence of the notches 133, the forward end portion of the connection member 130 is provided with a pair of protruding edges 132 on both sides thereof. The connection member 130 has a plurality of conductive portions 135 formed on one surface of the forward end portion at a predetermined interval in the widthwise direction. Furthermore, an insulating backing plate 137 is attached to the other surface of the connection member 130 opposite to the one surface provided with the conductive portions 135.

The insulator 101 comprises a first plate portion 111 as a base, a second plate portion 113 located above the first plate portion 111 in parallel thereto, a rear plate portion 115 (FIG. 5) connecting rear ends of the first and the second plate portions 111 and 113 to each other, a pair of side plate portions 117 connecting side ends of the first and the second plate portions 111 and 113 to each other, and a pair of locking arms 119 each of which is connected to the rear plate portion 115 with a predetermined gap from an inner wall surface of each of the side plate portions 117.

The second plate portion 113 extends from the rear side towards the front side over a dimension shorter than that of the first plate portion 111. Each of the locking arms 119 extends from the rear side towards the front side in parallel to the inner wall surface of each of the side plate portions 117. The rear plate portion 115 is perpendicular to the first plate portion 111.

As described above, the second plate portion 113 has a shorter dimension as compared with the first plate portion 111. The insulator 101 has an opening portion 102 formed at the front side to receive the forward end portion of the connection member 130. In the first embodiment, the locking arms 119 are made of a material same as that of the insulator 101. The locking arms 119 are integral with the insulator 101.

Referring to FIG. 6, the pressing member 105 is rotatable from an open position illustrated in FIG. 5 to a predetermined pressing position illustrated in FIG. 6. The operation of the pressing member 105 will later be described in detail.

Referring to FIGS. 7 and 8 in addition to FIGS. 5 and 6, each of the contacts 103 has a contacting base 103a located on an inner surface of the first plate portion 111, a pair of holding portions 103c extending upward from both side edges of the contacting base 103a, a connecting portion 103b extending from the holding portions 103c to the outside of the insulator 101 and a contacting spring portion 103d connected to one longitudinal end of the contacting base 103a and extending therefrom towards the other longitudinal end.

The contacting spring portion 103d extends generally in parallel to the contacting base 103a. The contacting spring portion 103d has a contact point 103e formed at its extending end to be brought into contact with each of the conductive portions 135 of the connection member 130. The contact point 103e of the contacting spring portion 103d is formed by arcuately bending the extending end portion of the contacting spring portion 103d so as to be connected to the conductive portion 135 of the connection member 130.

The contacts 103 are arranged in one-to-one correspondence in a plurality of compartments defined by a plurality of vertical partition walls 111h formed on the inner surface of the first plate portion 111. The contact points 103e protrude upward to a level higher than upper ends of the partition walls 111h. The contacting spring portions 103d are arranged in the opening portion 102 of the insulator 101. Each of the holding portions 103c has a support arm portion 103m.

The contacting base 103a has an auxiliary spring portion 103g extending from the other longitudinal end towards the one longitudinal end in parallel to the contacting base 103a. The auxiliary spring portion 103g has an extending end located beneath the contact point 103e.

The support arm portion 103m has a generally semicircular arm pivot 103f formed at its free end to protrude towards the contacting spring portion 103d. The arm pivot 103f serves as an axis of rotation of the pressing member 105 in a range of a predetermined arc. The arm pivot 103f has a generally semicircular shape so as to allow the rotation of the pressing member 105. The arm pivot 103f receives reactive force from the contacting spring portion 103d.

The holding portion 103c is provided with a supporting notch 103k formed below the support arm 103m to receive the forward end portion of the connection member 130. A combination of the contacting base 103a, the contacting spring portion 103d, and the auxiliary spring portion 103g is generally flat and almost annular as seen from a lateral side.

The contacting base 103a and the connecting portion 103b are connected to each other through a coupling portion 103h. The connecting portion 103b is inserted into a through hole formed in a printed circuit board (not shown) and is soldered thereto.

The pressing member 105 is located between the side plate portions 117. The pressing member 105 has a pair of shaft portions 105a (FIG. 4) formed on outer surfaces of a pair of pressing plates 106, respectively. The shaft portions 105a are rotatably supported by the side plate portions 117 so that the pressing member 105 is rotated from the open position to the predetermined pressing position to open and close the opening portion 102 above the contacting spring portions 103d. Each of the pressing plates 106 has a detecting projection 105d which enters into a gap between the inner surface of the side wall portion 117 and the locking arm 119 when the pressing member 105 is rotated to the predetermined pressing position over the contacting spring portions 103d.

The pressing member 105 has a flat pressing surface 105b for bringing the conductive portions 135 into contact with the contact points 103e when the pressing member 105 is rotated to the predetermined pressing position as illustrated in FIG. 6. The pressing surface 105b of the pressing member 105 presses the conductive portions 135 of the connection member 130 located on the contacting spring portions 103d to provide tight contact therebetween.

When the pressing member 105 is rotated to the predetermined pressing position, the side plate portions 117 and the pressing plates 106 are engaged with each other to form a locking arrangement for preventing deformation of the locking arms 119 when the pressing member 105 is rotated to close the opening portion 102 above the contacting spring portions 103d.

The locking arms 119 and the detecting projection 105d of the pressing member 105 form a detecting arrangement for detecting whether or not the conductive portions 135 of the connection member 130 are properly positioned on the contacting points 103e.

The locking arrangement comprises a pair of locking portions 125 formed on the inner surfaces of the side plate portions 117, respectively, and a pair of engaging projections 128 formed on the outer surfaces of the pressing plates 106. The engaging projections 128 are engaged with the locking portions 125 when the pressing member 105 is rotated to the predetermined pressing position to completely close the opening portion 102 above the contacting spring portions 103d.

Each of the locking arms 119 has an arm projection 121 formed on its one end at the front side and an arm spring portion 123 extending from the arm projection 121 towards the rear side. The arm projection 121 serves to guide the connection member 130 to the predetermined connecting position over the contacting spring portions 103d. When the connection member 130 is inserted between the locking arms 119, the arm spring portions 123 are pressed by the both side edges of the connection member 130 to be widened and deformed. Thus, the distance between the locking arms 119 is designed to be smaller than the width of the forward end portion of the connection member 130, i.e., the distance between the side edges.

Each of the arm projections 121 has a guide groove 121a to guide each of the side edges of the forward end portion of the connection member 130. The guide groove 121a has a tapered shape narrowing from the front side towards the rear side.

Turning back to FIG. 4, the connection member 130 has a hook receiving hole 139 formed at its forward end portion. On the other hand, the pressing member 105 has a hook portion 127 formed at its center to be engaged with the hook receiving hole 139 when the pressing member 105 is rotated to the predetermined pressing position to close the opening portion 102 over the contacting spring portions 103d. The hooking portion 127 is formed in the vicinity of the pressing surface 105b to protrude above the pressing surface 105b.

The arm pivot 103f formed adjacent to the holding portion 103c of the contact 103 is brought into contact with an upper surface of the one end of the pressing member 105 to hold the pressing member 105 rotated to the predetermined pressing position.

Referring to FIGS. 9 through 14 in addition, an operation of connecting the connection member 130 to the electrical connector will be described.

At first referring to FIG. 9, the both side edges of the forward end portion of the connection member 130 are inserted into the guide grooves 121a of the arm projections 121. At this time, the arm spring portions 123 are deformed by the both side edges of the forward end portion of the connection member 130 to displace the arm projections 121 towards the inner surfaces of the side plate portions 117. In this state, a gap between the inner surface of the side plate portion 117 and the arm projection 121 becomes small to inhibit the detecting projection 105d of the pressing member 105 from entering into the gap between the inner surface of the side plate portion 117 and the arm projection 121. Thus, the pressing member 105 is inhibited from being rotated.

Thus, the detecting arrangement comprising the locking arms 119 and the detecting projections 105d prevents the pressing member 105 from being undesirably rotated when the connection member 130 is not completely inserted. In other words, the detecting arrangement comprising the locking arms 119 and the detecting projections 105d detects incomplete connection of the connection member 130.

When the connection member 130 is further inserted rearward, the arm projections 121 enter into the notches 133 of the connection member 130 as illustrated in FIG. 10. At this time, the connection member 130 is completely inserted to the predetermined connecting position in the insulator 101. Then, each of the arm spring portions 123 is returned from a deformed position into an initial position. Therefore, during the connecting operation, a click feeling is obtained when the arm spring portion 123 returns from the deformed position into the initial position. The connection member 130 is inhibited from being released because the notches 133 are engaged with the arm projections 121. Thus, the connection member 130 is locked in a provisional locking condition.

Thereafter, when the pressing member 105 is rotated, the detecting projections 105d enter into the gaps between the inner wall surfaces of the side plate portions 117 and the arm projections 121, respectively, as illustrated in FIGS. 11 and 12. At this time, the engaging projections 128 formed on the side surfaces of the pressing plates 106 pass across the locking portions 125 to be fitted into grooves 117g formed on the inner surfaces of the side plate portions 117. Now, the engaging projections 128 are engaged with the locking portions 125 to inhibit the rotation of the pressing member 105 towards the open position.

Referring to FIG. 13 corresponding to FIG. 9, the connection member 130 is partly inserted between the locking arms 119. As seen from FIG. 13, the detecting projections 105d are interfered by the arm projections 121 in hatched portions depicted by A. Thus, incomplete connection is detected by the detecting projections 105d.

Referring to FIG. 14 corresponding to FIG. 10, the connection member 130 is completely inserted. In this state, the arm projections 121 are displaced outwards and no longer interfere the detecting projections 105.

Turning back to FIG. 10, when the detecting projections 105d enter into the gaps between the side plate portions 117 and the arm projections 121, the hook portion 126 of the pressing member 5 is inserted into and engaged with the hook receiving hole 139 of the connection member 130. The engagement between the hook receiving hole 139 and the hook portion 126 inhibits the connection member 130 from being undesirably released from the insulator 101. In order to remove the connection member 130 from the insulator 101, the above-mentioned operation is carried out in a reverse order.

The forward end portion of the connection member 130 is inserted into the supporting notches 103k of the contacts 103. When the forward end of the connection member 130 reaches the bottoms of the supporting notches 103k, the connection member 130 is completely inserted to the predetermined connecting position. In this event, the conductive portions 135 are brought into contact with the contact points 103e. Thereafter, when the pressing member 105 is rotated around the arm pivot 103f as illustrated in FIG. 6, the pressing surface 105b presses the connection member 130 against the contacting spring portions 103d to deform the contacting spring portions 103d. The forward end of the connection member 130 and the one end of the pressing member 105 are received in the supporting notches 103k. Thus, the forward end portion of the connection member 130 is fixedly clamped by the arm pivots 103f and the contacting spring portions 103d under spring force and reactive force, respectively.

Since each of the contacting spring portions 103d is located between the holding portions 103c, the connection member 130 is stably clamped by the holding portions 103c and the contact point 103e. The contact 103 of the above-mentioned shape provides stable connection irrespective of the shape of the insulator 101 supporting the contacts 103.

Referring to FIG. 15, the connection member 130 is modified in shape. Specifically, the connection member 130 does not have the notches 133 in the foregoing description. As seen from the figure, the connection member 130 simply has a pair of protruding edges 134 formed at its forward end portion to protrude in the widthwise direction. By the presence of the protruding edges 134, the connection member 130 is provided with a pair of step portions (engaging portions) 138. The step portions 138 have a function equivalent to that of the notches 133.

In the electrical connector according to the first embodiment of this invention, a single connector unit is formed by the insulator 101, the contacts 103, and the pressing member 105 with the locking and the detecting arrangements.

Referring to FIGS. 16 through 18, an electrical connector according to a second embodiment of this invention comprises a plurality of (two in the illustrated example) connector units mentioned above.

As illustrated in FIGS. 16 through 18, the electrical connector comprises an additional insulator 101', a plurality of additional contacts 103', and an additional pressing member 105' in addition to the insulator 101, the contacts 103, and the pressing member 105 described in conjunction with the first embodiment.

The insulator 101 is integrally coupled with the additional insulator 101' (FIG. 17) comprising a first additional plate portion 111', a second additional plate portion 113', and an additional rear plate portion 115'. Specifically, the first plate portion 111 of the insulator 101 integrally connected with a base plate portion 114 extending rearward. The base plate portion 114 is greater in thickness than the first plate portion 111. The second plate portion 113 of the insulator 101 is integrally connected with the first additional plate portion 111' extending rearward. Above the first additional plate portion 111', the second additional plate portion 113' similar to the second plate portion 113 of the insulator 101 extends in parallel to the first additional plate portion 111'. The first and the second additional plate portions 111' and 113' are connected by the additional rear plate portion 115' similar to the rear plate portion 115.

On the first additional plate portion 111', the additional contacts 103' similar to the contacts 103 and the additional pressing member 105' similar to the pressing member 105 are arranged in the manner similar to the first embodiment.

Thus, in the electrical connector of the second embodiment, a pair of the connector units each of which is described in conjunction with the first embodiment are arranged offset in the inserting direction and stacked in two stages in the vertical direction.

In the lower connector unit, the connection member 130 is inserted into the insulator 101 and the pressing member 105 is rotated. In the upper connector unit, an additional connection member 130' is inserted into the additional insulator 101' and the additional pressing member 105' is rotated. The connection member 130 and the additional connection member 130' are pressed by the pressing member 105 and the additional pressing member 105' to be connected to the contacts 103 and the additional contacts 103', respectively.

In the second embodiment, the pressing member 105 and the additional pressing member 105' are provided with two hook portions 127 and two additional hook portions 127', respectively. On the other hand, the connection member 130 and the additional connection member 130' are provided with two hook receiving holes 139 and the additional hook receiving holes 139', respectively. The hook receiving holes 139 and the additional hook receiving holes 139' are engaged with the two hook portions 127 and the two additional hook portions 127' in one-to-one correspondence.

The contacts 103 and the additional contacts 103' of the second embodiment are slightly different in shape from the contacts 103 in the first embodiment. Specifically, the coupling portion 103h of each of the contacts 3 extends along the base plate portion 114 in the second embodiment. Similarly, an additional coupling portion 103h' of each of the additional contacts 103' is longer than the coupling portion 103h in the first embodiment.

Other structures of the additional insulator 101', the additional contacts 103', and the additional pressing members 105' are similar to those of the insulator 101, the contacts 103, and the pressing member 105 of the first embodiment. Similar parts are designated by like reference numerals and will not be described any longer.

Referring to FIGS. 19 through 25, an electrical connector according to a third embodiment of this invention is adapted to removably connect the connection member 130 and a mating connector. For this purpose, the electrical connector is different in structure from the first embodiment in that a fitting portion for fitting the mating connector is provided.

In the following, description will mainly be directed to the fitting portion and the mating connector. The remaining structure for connection of the connection member 130 is similar to the first embodiment. The similar parts are designated by like reference numerals and will not be described any longer.

Referring to FIGS. 19 and 20, the electrical connector of the third embodiment has the fitting portion 151 extending rearward from the insulator 101 comprising the first and the second plate portions 111 and 113 and the side plate portions 117. The fitting portion 151 comprises a first fitting plate portion 111a, a second fitting plate portion 113a, and a fitting base portion 115a and is opened at its rear side. The fitting portion 151 has a cavity 151a defined between a rear opening and the fitting base portion 115a. In the cavity 151a, a plurality of connecting portions 153b of the contacts 103 extend from the fitting base portion 115a towards the rear opening.

Thus, the contact 103 is different from that of the first embodiment in that the connecting portion 153b of a pin shape straightly extends rearwards from the holding portion 103c.

As illustrated in FIG. 19, the mating connector comprises a mating insulator 161, a receiving portion 161a formed in the mating insulator 161, and a plurality of conductive mating contacts 162 arranged in the receiving portion 161a.

The mating insulator 161 is provided with an engagement operating section 161b formed on its upper surface. The engagement operating section 161b has elasticity. One end of the engagement operating section 161b is connected to the upper surface of the mating insulator 161.

Each of the mating contacts 162 has a socket portion 162a for receiving the connecting portion 153b to be connected thereto, a mating holding portion 162b supported by the mating insulator 161, and a cable holding portion 162c holding and connecting a cable 164.

The engagement operating portion 161b has an operating portion 161c formed at its one end to be movable up and down when manipulated by an operator, and a projecting portion 161d to be engaged with the fitting portion 151 when the mating connector is completely coupled to the fitting portion 151.

Specifically, the projecting portion 161d is engaged with a receiving projection 113d formed inside of the top end of the second fitting plate portion 113a. As the engagement between the fitting portion 151 and the mating connector, various fitting structures are known. Therefore, no further description will be made herein.

As illustrated in FIGS. 21 and 22, the connection member 130 is connected to the contacts 103 by rotating the pressing member 105. The connecting operation is similar to that described in conjunction with the first embodiment and will not be described any longer.

Referring to FIGS. 23 and 24, the contact 103 in the third embodiment is similar to that of the first embodiment except that the connecting portion 153b straightly extends rearward.

Referring to FIG. 25, the contact 103 is formed by punching a conductive plate by the use of a press into a desired pattern illustrated in the figure and by bending the plate. The pattern illustrated in the figure is common to the contact 103 in the first embodiment except the connecting portion 153b.

As will readily be understood, the contact 103 in the first and the second embodiments can easily be made by slightly modifying the pattern illustrated in FIG. 25.

Referring to FIGS. 26 and 27, an electrical connector according to a fourth embodiment of this invention comprises a pair of the connector units each of which is described in conjunction with the first embodiment. These connector units are connected to each other at their rear ends. Thus, the connector units are coupled symmetrically in the inserting direction.

In the electrical connector, a pair of the connection members 130 illustrated in FIG. 15 can be used. The connection members 130 are inserted into the electrical connector from the front and the rear sides, i.e., into first and second connector units, respectively. The connection members 130 are connected to each other through the electrical connector.

As illustrated in FIGS. 26 and 27, the electrical connector comprises the first connector unit including the insulator 101, the contacts 103, and the pressing member 105 similar to the first embodiment, and the second connector unit including an additional insulator 101', a plurality of additional contacts 103', and an additional pressing member 105'.

The insulator 101 is integrally coupled at its rear end with the additional insulator 101 comprising a first additional plate portion 111' and a second additional plate portion 113'. The first plate portion 111 of the insulator 101 is connected to the first additional plate portion 111' extending rearward. The second plate portion 113 of the insulator 101 is connected to the second additional plate portion 113' extending rearward.

On the first additional plate portion 111' connected to the first plate portion 111, the additional contacts 103' similar to the contacts 103 formed on the first plate portion 111 and the additional pressing member 105' similar to the pressing member 105 are attached in the manner similar to the first embodiment.

Thus, the connector units each of which is similar to that described in the first embodiment are symmetrically coupled in the inserting direction.

In the above-mentioned electrical connector, the connection member 130 is inserted from the front side to a first predetermined connecting position over the contacts 103 and the pressing member 105 is rotated as illustrated in FIG. 18. In addition, an additional connection member 130' similar to the connection member 130 is inserted from the rear side to a second predetermined connecting position over the additional contacts 103' and the additional pressing member 105' is rotated. The connection member 130 and the additional connection member 130' are pressed by the pressing member 105 and the additional pressing member 105' to be connected to the contacts 103 and the additional contacts 103', respectively.

Each of the contacts 103 and each corresponding one of the additional contacts 103' are connected to each other through a coupling portion 103y extending from lower parts of the holding portion 103c of the contact 103 and an additional holding portion 103c' of the additional contact 103', respectively. The coupling portion 103y is formed by bending the lower parts of the holding portion 103c and the additional holding portion 103c'. The contact 103 and the additional contact 103' are symmetrical with respect to the coupling portion 103y.

Each of the contacts 103 and the additional contacts 103' is similar in structure to the contact 103 of the first embodiment except that the coupling portion 103h and the connecting portion 105b in the first embodiment are omitted. Therefore, the remaining structure of the electrical connector and the connection of the connecting member 130 will not be described any longer.

The additional insulator 101' and the additional pressing member 105' are similar in structure to the insulator 101 and the pressing member 105 in the first embodiment. Similar parts are described by like reference numerals and will not be described any longer.

As described above, when the connection member is not properly inserted to the predetermined connecting position in the insulator, the detecting arrangement inhibits the rotation of the pressing member. Therefore, according to this invention, a further progress of the connecting operation is inhibited in case where the connection member is incompletely inserted.

During the connecting operation, the connection member is temporarily held by the locking arms. Therefore, it is possible to prevent the connection member from being easily released from the insulator under external force or vibration before the pressing member is completely inserted and locked. Thus, the connecting operation is facilitated.

Upon insertion of the connection member into the insulator, click feeling is obtained by the displacement of the locking arms. Therefore, proper insertion of the connection member to the predetermined connecting position is readily confirmed.

After the pressing member is rotated to the predetermined pressing position, the movement of the locking arms is inhibited by the locking portions. Therefore, the connecting member can be held with increased holding force.

The forward end portion of the connection member is completely clamped by the arm pivot and the contacting spring portion under spring force and reactive force, respectively.

Since the contacting spring portion is located between a pair of the holding portions, the connecting member is stably supported to provide reliable connection.

Thus, the contacts of the above-mentioned shape are free from the influence of the shape of the insulator holding the contacts.

Furthermore, the contact has the arm pivot and the supporting notch so as to keep stable and reliable connection even if the connection member is deformed.