Abstract:
A cam structure is pivotally moving between electronic parts to act on the other parts, which enables the action on said other parts upon pivotal movement to be varied by partly modifying a cam shape of the cam structure. For example, when the cam structure is pivotally moved in a connector to bring contacts into contact with a connecting object inserted in the connector, contact pressure of the contacts is controlled by partly modifying the cam shape of the cam structure. The cam structure has advantages that its cam portion can be pivotally moved by a slight force without requiring any large force and being capable of shifting the timing at which the cam contacts the mating parts depending upon customers specifications.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention relates to a cam structure for use in electric and electronic appliances and being capable of varying forces and actions to be applied to a mating object by modifying its cam shape, and more particularly to a connector using such a cam structure.  
         [0002]     In the art of mechanical structures, it has long been used to vary a cam shape as a cam mechanism to change the timing of action caused by the cam mechanism. In the art of electric and electronic appliances, however, aside from miniaturization of such appliances, it have not been performed to vary a cam shape for changing the timing.  
         [0003]     In general, connectors for use in, for example, mobile phones, charge coupled device (CCD) cameras and the like are much thinner and having contacts arranged in extremely narrow pitches (so-called lighter and more compact connectors). These connectors each mainly comprise a housing, contacts and a pivoting member so that after a flexible printed circuit board has been inserted into the housing, the pivoting member is rotated on a fitting side or opposite side thereto, thereby bringing contact portions of the contacts into contact with the flexible printed circuit board. The housing is provided with a required number of inserting holes for inserting the contacts and also a fitting opening into which the flexible printed circuit board is inserted. The contacts each mainly comprise a contact portion adapted to contact the circuit board, a connection portion to be connected to a substrate or the like, and a fixed portion to be fixed to the housing. The contacts are fixed to the housing by means of press-fitting or the like.  
         [0004]     By way of example, described hereafter are Patent Literature 1 (Japanese Patent Application Opened No. 2003-297,489) as an example of a connector of zero-insertion force (ZIF) type, a so-called “back-lock type”, Patent Literature 2 (Japanese Patent Application Opened No. H11-307,198/1999), and Patent Literature 3 (Japanese Patent Application Opened No. 2004-71,160) proposed by the applicant of the present application. Moreover, described as examples of locking structures for a flexible printed circuit board are Patent Literature 4 (Japanese Utility Model Application Opened No. H6-82,783/1994), Patent Literature 5 (Japanese Patent Application No. 2003-422,258) proposed by the applicant of the present application, Patent Literature 6 (Japanese Patent Application No. 2004-307,793), and Patent Literature 7 (Japanese Patent Application No. 2005-178,666).  
         [0005]     Patent Literature 1  
         [0006]     According to the Abstract of the Japanese Patent Application Opened No. 2003-297,489, the invention has an object to provide a connector having a reduced overall height including an actuator to be operated by a slight actuating force and enabling contacts to move large distances to ensure reliable connection of the contacts. In the disclosed connector, the actuator includes a cam portion and an actuating portion and is formed between the cam portion and the actuating portion with relief grooves into and from which the forward ends of spring portions of the contacts are inserted and removed. The actuator is rotated clockwise about a fulcrum so that the cam portion causes the spring portions and jointing spring portions of the contacts to be elastically deformed to embrace a flexible printed circuit board between projections of contact portions of the contacts, with the result that patterns of the circuit board are connected through terminal portions of the respective contacts to a printed substrate. An insulator includes a ceiling portion for covering the contact portions of the respective contacts and a guide portion formed forwardly of and below the ceiling portion for guiding the flexible printed circuit board being inserted into the connector.  
         [0007]     Patent Literature 2  
         [0008]     According to the Abstract of the Japanese Patent Application Opened No. H11-307,198 (1999), the invention has an object to provide a connector for a printed circuit board, connecting a plurality of terminals and holding the flexible printed circuit board, which achieves improved operationality and holding performance. The disclosed connector includes a housing having an inserting groove for inserting a flexible printed circuit board or the like, a plurality of contacts arranged side by side so as to permit their contact portions to extend into and retract from the inserting groove, and an actuating member having a plurality of cams and being pivotally movable between a connecting position and a release position. When the actuating member is in the connecting position, operated portions of the contacts are urged by the cams to cause the contact portions to extend into the inserting groove so that the contact portions are pressed against terminals of the flexible printed circuit board or the like, thereby electrically connecting the terminals to the contacts and holding the circuit board or the like. When the actuating member is in the release position, operated portions of some contacts are urged by the cams to cause the contact portions to slightly extend into the inserting groove so that the contact portions abut against the flexible printed circuit board to temporarily hold the circuit board, and the contact portions of the remaining contacts are caused to retract relative to the inserting groove.  
         [0009]     Patent Literature 3  
         [0010]     According to the Abstract of the Japanese Patent Application Opened No. 2004-71,160, the invention has an object to provide a connector being capable of securely pressing a flexible printed circuit board or flexible flat cable against contact portions of contacts by means of a slider without degrading strengths and specifications of respective components, and being superior in operationality, and achieving narrow pitches of conductors and reduced overall height of the connector. Disclosed is the connector whose contacts each comprise a contact portion, and a connection portion, and further an elastic portion and a fulcrum between the contact portion and the connection portion, and the contact portion, the elastic portion, the fulcrum and the connection portion are arranged substantially in the form of a crank. Further, the contacts are each provided with a pressure receiving portion extending from the elastic portion at a location facing to the connection portion. The slider is provided with urging portions continuously arranged side by side in a row in its longitudinal direction, and is mounted on a housing so as to permit the urging portions to be pivotally moved between the connection portions and pressure receiving portions of the contacts.  
         [0011]     Patent Literature 4  
         [0012]     According to the Abstract of the Japanese Utility Model Application Opened No. H6-82,783 (1994), the utility model has an object to provide a connector being capable of easily anchoring by pawls of a slider a flexible flat cable even having a rigid reinforcement plate attached to its rear face. Disclosed is a connector construction comprising a housing including contact pins therein and formed with a fitting space into which a flat cable is inserted, and a slider mounted on the housing so that the slider can be detachably inserted into the fitting space of the housing and is pivotally movable outside of the housing upon removal, thereby bringing the flat cable into electrical contact with the contact pins by forcing the slider into the fitting space after the flat cable has been inserted into said fitting space, wherein said slider is provided with on its flat cable abutting surface with anchoring protrusions adapted to be inserted into and anchored in anchoring portions formed in the flexible cables and formed in a reinforcement plate attached to the rear face of the flexible cable.  
         [0013]     Patent Literature 5  
         [0014]     In Japanese Patent Application No. 2003-422,258 proposed by the applicant of the present application as a construction for locking a flexible printed circuit board, the invention has an object to provide a connector ensuring a required holding force for a flexible printed circuit board, even if the number of conductors is small, without causing any defective connection. According to this invention, the connector to be detachably fitted with a flexible printed circuit board includes a required number of contacts each having a contact portion adapted to contact a flexible printed circuit board, and a housing holding and fixing the contacts therein and having a fitting opening into which the flexible printed circuit board is inserted, wherein the flexible printed circuit board is provided with anchoring portions and a locking member having engaging portions adapted to engage the anchoring portions is mounted on the housing so that the flexible printed circuit board is fixed so as not to be removed from the housing by causing the engaging portions of the locking member to be engaged with the anchoring portions of the printed circuit board, and a further reliable locking can be achieved by providing grooves in positions corresponding to the engaging portions.  
         [0015]     Patent Literature 6  
         [0016]     In the Abstract of Japanese Patent Application No. 2004-307,793 proposed by the applicant of the present application in order to improve dust-proof property, the invention has an object to provide a connector with high dust-proofing capability and requiring little or no insertion force for a flexible printed circuit board. The connector includes a required number of contacts, a housing, and a pivoting member, wherein the contacts each comprise at least a contact portion, a connection portion, a fulcrum portion, a jointing portion and a pressure receiving portion, and are substantially H-shaped, and when urging portions of the pivoting member are pivotally moved between the connection portions and the pressure receiving portions to bring the contact portions into contact with a connecting object, and wherein the housing comprises a ceiling portion for covering the contact portions of the contacts and an upper wall for covering the pressure receiving portions of the contacts, and the pivoting member comprises an actuating portion, the urging portions, anchoring holes, and a cover portion which covers the tail portions of the contacts after the pivoting member has been pivoted.  
         [0017]     Patent Literature 7  
         [0018]     According to the Abstract of Japanese Patent Application No. 2005-178,666, proposed by the applicant of the present application for the purpose of improving dust-proofing, the invention has an object to provide a connector improved in dust-proofing and achieving no insertion force for flexible printed circuit board. A connector includes a required number of contacts, a housing, and a pivoting member, wherein the contacts each at least having a contact portion, a connection portion, a fulcrum portion, a jointing portion, and a pressure receiving portion, these portions being arranged substantially in the form of an H-shape, and the pivoting member is so constructed that upon pivotal movement of urging portions of the pivoting member between the connection portions and the pressure receiving portions of the contacts, the contact portions are brought into contact with a connecting object, and wherein the housing has a ceiling portion for covering the contact portions of the contacts and an upper wall for covering the pressure receiving portions of the contacts, and the pivoting member has an actuating portion, urging portions, anchoring holes, and a cover portion so that upon pivotal movement of the pivoting member, gaps between the tip of the upper wall and the actuating portion and between the upper wall and the tip of the pivoting member opposite from the side of the actuating portion of the pivoting member are made as narrow as possible within a range which does not allow the pivotally moving pivoting member to touch the upper wall of the housing.  
         [0019]     In the art of the connectors also, constructions have been increasingly used, whose contacts are brought into contact with a connecting object such as a flexible printed circuit board and the like by utilizing a cam structure as in the Patent Structure 1 to 7. In the connectors having the comparatively large numbers of conductors of the Patent Literatures 1 to 7, there are ones having more of eighty conductors. In order to bring more of eighty contacts into contact with a flexible printed circuit board by rotating a cam at a time, a comparatively great force in excess of approximately 90N would be needed. On the other hand, connectors have been miniaturized so that parts to be operated for rotating the cam have also been miniaturized, which makes it impossible to rotate the cam manually.  
       SUMMARY OF THE INVENTION  
       [0020]     In view of the problems of the prior art described above, the invention has an object to provide a cam structure allowing its cam portion to be rotated without requiring any large force and being capable of shifting the timing at which the cam contacts mating parts depending upon customer&#39;s specifications.  
         [0021]     The above object can be achieved by the cam structure pivotally moving between electronic parts to act on the other parts, which enables the action on the other parts upon pivotal movement to be varied by partly modifying a cam shape of the cam structure.  
         [0022]     In the cam structure pivotally moving in a connector  10  to bring contacts  14  and  16  into contact with a connecting object inserted in the connector  10 , contact pressure of said contacts  14  and  16  can be controlled by partly modifying a cam shape of said cam structure.  
         [0023]     In the connector  10  recited in claim  3  detachably fitting with a connecting object, including a required number of contacts  14  and  16  each having a contact portion  26  adapted to contact said connecting object, a housing  12  holding and fixing said contacts  14  and  16  therein and having a fitting opening  20  for inserting said connecting object thereinto, and a pivoting member  18  having a cam portion  54  which urges said contacts  14  and  16 , said contact  14  and  16  each have at one end the contact portion  26  adapted to contact said connecting object and at the other end a pressure receiving portion  32  adapted to be urged by said cam portion  54  of said pivoting member  18 , and said pivoting member  18  is pivotally mounted on said housing  12  so as to urge the pressure receiving portions  32  of said contacts  14  and  16  upon pivotal movement of said pivoting member  18 , while contact pressure of said contacts  14  and  16  against said connecting object is controlled by partly modifying a cam shape of said cam portion  54 .  
         [0024]     In the connector  10  recited in claim  4 , said contacts  14  and  16  each comprise a first piece  22  including at one end the contact portion  26  adapted to contact said connecting object and at the other end the pressure receiving portion  32  to be urged by the cam portion  54  of said pivoting member  18 , a second piece  24  including at one end an extension portion  36  having a further contact portion  26  or a fixed portion  38  and at the other end a connection portion  40  to be connected to a substrate, and a jointing fulcrum  30  for connecting said first and second pieces  22 ,  24 , and said housing  12  having a ceiling portion  50  for covering the contact portions  26  of said contacts  14  and  16 , while said pivoting member  18  comprises an actuating portion  56  for pivotally moving the pivoting member  18 , the cam portion  54  having longitudinally continuous cam parts, and anchoring holes  58  provided independently from one another into which said pressure receiving portions  32  can be inserted, said pivoting member  18  being pivotally mounted on said housing  12  so that said cam portion  54  is pivotally movable between the connection portions  40  and the pressure receiving portions  32  of said contacts  14  and  16 .  
         [0025]     In the connector recited in claim  5 , said contacts  14  and  16  each comprise a first piece  22  including at one end the contact portion  26  adapted to contact said connecting object and at the other end the pressure receiving portion  32  to be urged by the cam portion  54  of said pivoting member  18 , a second piece  24  including at one end a connection portion  40  to be connected to a substrate and at the other end an extension portion  36 , and a jointing fulcrum  30  for connecting said first and second pieces  22 ,  24 , and said housing  12  having a ceiling portion  50  for covering the contact portions  26  of said contacts  14  and  16 , while said pivoting member  18  comprises an actuating portion  56  for pivotally moving the pivoting member, the cam portion  54  having longitudinally continuous cam parts, and anchoring holes  58  provided independently from one another into which said pressure receiving portions  32  can be inserted, said pivoting member  18  being pivotally mounted on said housing  12  so that said cam portion  54  is pivotally movable between the connection portions  40  and the pressure receiving portions  32  of said contacts  14  and  16 .  
         [0026]     In the connector  10  recited in claim  6 , each of said contacts  14  and  16  is provided with a further contact portion  26  between said connection portion  40  and said jointing fulcrum  30 . In the connector  10  recited in claim  7 , angle of said cam portion  54  starting from 10° is varied in increments of 5° for 10 to 20 contacts.  
         [0027]     As can be seen from the above description, the cam structure according to the invention and the connector using the cam structure can bring about the following functions and effects.  
         [0028]     (1) In the cam structure pivotally moving between electronic parts to act on the other parts, upon pivotal movement, the action on said other parts is varied by partly modifying a cam shape of said cam structure. Therefore, the timing at which the cam contacts the other parts can be easily shifted.  
         [0029]     (2) In the cam structure pivotally moving in a connector  10  to bring contacts  14  and  16  into contact with a connecting object inserted in said connector  10 , contact pressure of said contacts  14  and  16  is controlled by partly modifying a cam shape of said cam structure. Consequently, the contacting timing for the contacts can be easily shifted.  
         [0030]     (3) The connector  10  recited in claim  3  detachably fitting with a connecting object, includes a required number of contacts  14  and  16  each having a contact portion  26  adapted to contact said connecting object, a housing  12  holding and fixing said contacts  14  and  16  therein and having a fitting opening  20  for inserting said connecting object thereinto, and a pivoting member  18  having a cam portion  54  which urges said contacts  14  and  16 , wherein said contacts  14  and  16  each have at one end the contact portion  26  adapted to contact said connecting object and at the other end a pressure receiving portion  32  adapted to be urged by said cam portion  54  of said pivoting member  18 , and wherein said pivoting member  18  is pivotally mounted on said housing  12  so as to urge the pressure receiving portions  32  of said contacts  14  and  16  upon pivotal movement of said pivoting member  18 , while contact pressure of said contacts  14  and  16  against said connecting object is controlled by partly modifying a cam shape of said cam portion  54 . Accordingly, the contacting timing for the contacts can be easily shifted, and the force by which the cam is rotated can be easily changed.  
         [0031]     (4) In the connector  10  recited in claim  4 , said contacts  14  and  16  each comprise a first piece  22  including at one end the contact portion  26  adapted to contact said connecting object and at the other end the pressure receiving portion  32  to be urged by the cam portion  54  of said pivoting member  18 , a second piece  24  including at one end an extension portion  36  having a further contact portion  26  or a fixed portion  38  and at the other end a connection portion  40  to be connected to a substrate, and a jointing fulcrum  30  for connecting said first and second pieces  22 ,  24 , and said housing  12  having a ceiling portion  50  for covering the contact portions  26  of said contacts  14  and  16 , while said pivoting member  18  comprises an actuating portion  56  for pivotally moving the pivoting member  18 , the cam portion  54  having longitudinally continuous cam parts, and anchoring holes  58  provided independently from one another into which said pressure receiving portions  32  can be inserted, said pivoting member  18  being pivotally mounted on said housing  12  so that said cam portion  54  is pivotally movable between the connection portions  40  and the pressure receiving portions  32  of said contacts  14  and  16 . Consequently, the contacting timing for the contacts can be easily shifted, and the force by which the cam is rotated can be easily changed. A reduced overall height and miniaturization of the connector can also be accomplished.  
         [0032]     (5) In the connector recited in claim  5 , said contacts  14  and  16  each comprise a first piece  22  including at one end the contact portion  26  adapted to contact said connecting object and at the other end the pressure receiving portion  32  to be urged by the cam portion  54  of said pivoting member  18 , a second piece  24  including at one end a connection portion  40  to be connected to a substrate and at the other end an extension portion  36 , and a jointing fulcrum  30  for connecting said first and second pieces  22 ,  24 , and said housing  12  having a ceiling portion  50  for covering the contact portions  26  of said contacts  14  and  16 , while said pivoting member  18  comprises an actuating portion  56  for pivotally moving the pivoting member, the cam portion  54  having longitudinally continuous cam parts, and anchoring holes  58  provided independently from one another into which said pressure receiving portions  32  can be inserted, said pivoting member  18  being pivotally mounted on said housing  12  so that said cam portion  54  is pivotally movable between the connection portions  40  and the pressure receiving portions  32  of said contacts  14  and  16 . Accordingly, the contacting timing for the contacts can be easily shifted, and the force by which the cam is rotated can be easily changed. A reduced overall height and miniaturization of the connector can also be accomplished.  
         [0033]     (6) In the connector  10  recited in claim  6 , each of said contacts  14  and  16  is provided with a further contact portion  26  between said connection portion  40  and said jointing fulcrum  30 . Accordingly, the contacting timing for the contacts can be easily shifted, and the force by which the cam is rotated can be easily changed. A reduced overall height and miniaturization of the connector can also be accomplished.  
         [0034]     (7) In the connector  10  recited in claim  7 , angle of said cam portion  54  starting from 10° is varied in increments of 5° for 10 to 20 contacts. Therefore, the force by which the cam is rotated can be distributed or dispersed so that the cam can readily be rotated (pivotally rotated), thereby achieving stable electrical connection. These values such as angles and number of contacts are obtained by reasonable analysis as described later in the descriptions of the embodiments, but are not mere design matters.  
         [0035]     The invention will be more fully understood by referring to the following detailed specification and claims taken in connection with the appended drawings. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0036]      FIG. 1A  is a perspective view illustrating a cam shape for mitigating turning force according to the invention;  
         [0037]      FIG. 1B  is a side view illustrating the cam shape for mitigating turning force according to the invention;  
         [0038]      FIG. 2A  is a perspective view of the connector according to the invention with the pivoting member opened, viewed from the side inserting a flexible printed circuit board;  
         [0039]      FIG. 2B  is a perspective view of the connector shown in  FIG. 2A  with the pivoting member closed;  
         [0040]      FIG. 3  is a perspective view of the pivoting member;  
         [0041]      FIG. 4  is a perspective view of a housing of the connector according to the invention;  
         [0042]      FIG. 5A  is a perspective view of a contact of one kind used in the connector according to the invention;  
         [0043]      FIG. 5B  is a perspective view of a contact of the other kind used in the connector according to the invention;  
         [0044]      FIG. 6A  is a sectional view of the connector according to the invention with the pivoting member opened, taken along one contact of the one kind;  
         [0045]      FIG. 6B  is a sectional view of the connector according to the invention with the pivoting member closed, taken along one contact of the one kind;  
         [0046]      FIG. 7A  is a sectional view of the connector according to the invention with the pivoting member opened, taken along one contact of the other kind;  
         [0047]      FIG. 7B  is a sectional view of the connector according to the invention with the pivoting member closed, taken along one contact of the other kind;  
         [0048]      FIG. 8A  is the connector according to the invention and a flexible printed circuit board before being inserted into the connector;  
         [0049]      FIG. 8B  is the connector according to the invention with the flexible printed circuit board inserted; and  
         [0050]      FIG. 9  is a graph illustrating analysis results of reaction forces of a cam whose angles are changed. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0051]     One embodiment of a connector using a cam structure according to the invention will be explained with reference to FIGS.  1  to  9 .  FIG. 1A  is a perspective view illustrating a shape of the cam for mitigating turning force, and  FIG. 1B  is a side view of the cam shown in  FIG. 1A .  FIG. 2A  is a perspective view of the connector with a pivoting member opened, viewed from the inserting side of a flexible printed circuit board, while  FIG. 2B  is a perspective view of the connector of the  FIG. 2A  with the pivoting member closed.  FIG. 3  is a perspective view of the pivoting member.  FIG. 4  is a perspective view of the housing of the connector.  FIG. 5A  is a perspective view of a contact of one kind, and  FIG. 5B  is a perspective view of a contact of the other kind.  FIG. 6A  is a sectional view of the connector taken along a contact of the one kind with the pivoting member opened, while  FIG. 6B  is a sectional view of the connector shown in  FIG. 6A  with the pivoting member closed.  FIG. 7A  is a sectional view of the connector taken along a contact of the other kind with the pivoting member opened, while  FIG. 7B  is a sectional view of the connector shown in  FIG. 7A  with the pivoting member closed.  FIG. 8A  is a perspective view of the connector and a flexible printed circuit board before being inserted, and  FIG. 8B  is a perspective view similar to  FIG. 8A  but with the board inserted.  FIG. 9  is a graph illustrating analysis results of reaction forces of a cam whose angles are changed.  
         [0052]     The connector of the illustrated embodiment mainly comprises a housing  12 , a pivoting member  18  and contacts  14  and  16 . With the connector  10 , the contacts  14  and  16  of the two kinds are inserted into the housing  12  alternately in different or opposite directions so that the contacts  14  and  16  are alternately staggered relative to each other, thereby achieving a narrower pitch and a reduced overall height of the connector.  
         [0053]     First, the cam structure of the subject feature of the invention will be explained together with analysis results according to ANSYS with reference to  FIGS. 1A and 1B .  FIG. 9  is a graph illustrating the analysis results of reaction forces of a cam whose angles are changed as 0° (standard surface), 10°, 15°, 20°, 25° and 30° for the contacts. As can be seen in the graph shown in  FIG. 9 , starting points of respective curves to which reaction forces are initially applied are generally shifted, but terminal points of the respective curves substantially coincide with one another, and the reaction forces of the cam at the terminal points become substantially 1.1N per one contact. From these results, it will be understood that the timing of the reaction forces can be delayed by changing the angles of the cam and that when the number of contacts is n, the total of the reaction forces amounts to n times 1.1N (n×1.1N). This value is preferably of the order of 10N to 20N in order to facilitate manual rotation of the cam or the pivoting member. In the illustrated embodiment, starting from 10° the angle is increased in increments of 5° for 15 contacts as shown in  FIG. 1B . In other words, the number of the contacts is 80, and the cam part of angle 10° is for the first to the fifteenth contacts, the cam part of angle 15° for the sixteenth to thirtieth contacts, the cam part of angle 20° for the thirty-first to the forty-fifth contacts, the cam part of angle 25° for the forty-sixth to the sixtieth contacts, the cam part of angle 30° for the sixty-first to the seventy-fifth contacts, and the cam part of standard surface (0°) for the seventy-sixth to the eightieth contacts. Continuing with the description of the changing the angles for the contacts referring to the perspective view of  FIG. 1A , the standard surface (0°) of the cam portion  54  is shown at its left end, and the cam parts of 10°, 20°, and 30° are located side by side in this order toward its right end. Reference numerals  55  in  FIG. 1A  denote such cam parts of various angles.  
         [0054]     The contacts  14  and  16  of the two kinds will be explained with reference to  FIGS. 5A and 5B . The contacts  14  and  16  of the two kinds are made of a metal and formed by means of the press-working of the known technique. Preferred metals from which to form the contacts  14  and  16  include brass, beryllium copper, phosphor bronze and the like which comply with the requirements such as springiness, electric conductivity and the like.  
         [0055]     First, the contact  14  of the one kind shown in  FIG. 5A  will be explained. Said contact  14  of the one kind is of substantially an H-shape as shown in  FIG. 5A  and at least comprises a contact portion  26  (at the upper part viewed in  FIG. 5A ) adapted to contact said flexible printed circuit board  64 , a connection portion  40  to be connected to a substrate or the like, a fixed portion  38  to be fixed to said housing  12 , a jointing fulcrum  30 , and a pressure receiving portion  32  adapted to be urged by the pivoting member  18 . Said contact portion  26  and said pressure receiving portion  32  are provided at both the ends of a first piece  22  substantially in the form of a crank. Said pressure receiving portion  32  is provided at its end with a projection  42  inwardly extending. The contact  14  comprises a second piece  24  including on the side of one end an extension portion  36  having the fixed portion  38  to be inserted into said housing  12 , and on the side of the other end the connection portion  40  to be connected to the substrate. Said first piece  22  and said second piece  24  are connected to each other substantially at their mid portions by the jointing fulcrum  30 . Said contact portion  26 , said jointing fulcrum  30  and said connection portion  40  are arranged substantially in the form of a crank. Said connection portion  40  is provided with a protrusion base  44  extending toward said pressure receiving portion  32  so that a cam portion  54  of said pivoting member  18  can be pivotally rotated between said pressure receiving portions  32  and said protrusion bases  44  of the contacts  14 . In the illustrated embodiment, said contact  14  is provided in the proximity of the jointing fulcrum  30  with an inclined portion  28  facing to the fitting opening  20  of the housing  12  for contributing to a reduced overall height of the connector. Moreover, said protrusion base  44  serves to adjust the distance between the pressure receiving portion  32  and the connection portion  40  for achieving the stable pivotal movement of the cam portion  54  of said pivoting member  18 . The extending height of the protrusion base  44  may be suitably designed in consideration of such a function of the protrusion base  44 .  
         [0056]     The location of said connection portion  40  may be suitably designed in consideration of positions of lands and patterns of a substrate, narrow spaces and the like. In other words, said connection portion  40  may be provided on the side facing to said contact portion  26  or to said pressure receiving portion  32  depending on requirements and specifications of customers. Moreover, said connection portions  40  of said contacts may be arranged to be staggered relative to each other depending on positions of lands of a substrate. In said contact  14  of the one kind, said connection portion  40  is provided in the position facing to said pressure receiving portion  32 . Said contact portion  26  is in the form of a protrusion for the purpose of facilitating the contact with the flexible printed circuit board  64 . Although said connection portions  40  are of a surface mounting type (SMT) in the illustrated embodiment as shown in  FIG. 5A , it is to be understood that they may be of a dip type. A further contact portion  26  may be provided on the position facing to said first mentioned contact portion  26  so that a flexible printed circuit board  64  is embraced by the two opposite contact portions  26  depending upon specifications of said flexible printed circuit board  64 . In the illustrated embodiment, furthermore, said contact  14  of the one kind is provided with the extension portion  36  extending from said jointing fulcrum  30  in a manner facing to said contact portion  26 , and the extension portion  36  is provided thereon with the fixed portion  38  for fixing the contact  14  to said housing  12 . The size and shape of said fixed portion  38  may be suitably designed in consideration of the holding force for the contact  14 , the strength of said housing  12  and the like.  
         [0057]     Said jointing fulcrum  30  and said pressure receiving portion  32  will perform the following functions upon insertion of said flexible printed circuit board  64  into the housing  12 . After said flexible printed circuit board  64  has been inserted into the fitting opening  20  of said housing  12 , when the cam portion  54  of said pivoting member  18  is pivotally moved between the pressure receiving portions  32  and the protrusion bases  44  of the connection portions  40  of said contacts  14 , said pressure receiving portions  32  are raised by the cam portion  54  so that the upper ends of the jointing fulcrums  30  are tilted toward said contact portions  26  about the lower ends (viewed in  FIG. 5A ) of the jointing fulcrums  30 , thereby causing said contact portions  26  to be urged or pressed against said flexible printed circuit board  64 . Sizes and shapes of said jointing fulcrums  30  and said pressure receiving portions  32  may be suitably designed so as to be able to perform such functions described above. The pressure receiving portion  32  of said contact  14  is preferably provided at its distal end with the projection  42  as described above which is brought into engagement with one of anchoring holes  58  of said pivoting member  18  when the cam portion  54  of the pivoting member  18  is pivotally moved between the pressure receiving portion  32  and the protrusion base  44  of the connection portion  40  of the contact  14 . The engagement of the projections  42  with the anchoring holes  58  of said pivoting member  18  will resist to strong reaction force against the pivotal movement of the pivoting member  18 . The size of said projection  42  may be any one insofar as it serves to achieve the purpose described above, and may be suitably designed so as to engage the anchoring hole of the pivoting member  18 .  
         [0058]     The contacts  16  of the other kind will then be explained. Differences from the contacts  14  already described will only be explained. As is also the case in said contact  14  of the one kind, said contact  16  of the other kind is of substantially an H-shape as shown in  FIG. 5B . The contact  16  mainly comprises a contact portion  26  (at the upper part viewed in  FIG. 5B ) adapted to contact the flexible printed circuit board  64 , a connection portion  40  to be connected to the substrate, a fixed portion  38  to be fixed to the housing  12 , a jointing fulcrum  30 , and a pressure receiving portion  32  to be urged by said pivoting member  18 . Said contact portion  26 , said jointing fulcrum  30  and said connection portion  40  are arranged substantially in a U-shape. While said connection portions  40  are of a surface mounting type (SMT) similar to the contact  14  of the one kind, it will be apparent that they may be of a dip type.  
         [0059]     The differences between said contacts  14  and  16  of the two kinds lie in the fact that the connection portions  40  and the extension portions  36  are reversely positioned to each other in the two kinds, aside from some geometric differences. In other words, with said contact  14  of the one kind, said connection portion  40  is located on the side facing to said pressure receiving portion  32  and said extension portion  36  is located on the side facing to said contact portion  26 . In contrast herewith, with said contact  16  of the other kind, said connection portion  40  is located on the side facing to said contact portion  26  and said extension portion  36  is located on the side facing to said pressure receiving portion  32 . The extension portion  36  of said contacts  16  of the other kind is provided with the fixed portion  38  for fixing the contact  16  to said housing  12 .  
         [0060]     The pivoting member  18  will then be explained. The pivoting member  18  is formed from an electrically insulating plastic material by means of the injection molding of the known technique. The materials for the pivoting member may be selected in consideration of dimensional stability, workability, manufacturing cost and the like and generally include polybutylene terephthalate (PBT), polyamide (66PA or 46PA), liquid crystal polymer (LCP), polycarbonate (PC) and the like and combination thereof.  
         [0061]     Said pivoting member  18  mainly comprises axles for pivotally mounting the pivoting member  18  on the housing  12 , the cam portion  54  for urging or pressing the pressure receiving portions  32  of said contacts  14  and  16 , the anchoring holes  58  adapted to engage the projections  42  of said contacts  14  and  16 , respectively, and an actuating portion  56 . In the illustrated embodiment, said pivoting member  18  has a substantially U-shaped cross-section. Said axles are a fulcrum for the pivotal movement of the pivoting member  18  and suitably fitted in bearings or holes at the longitudinal ends of the housing  12  to allow the pivoting member to be pivotally moved. There are clearances in the bearings of the housing  12  in relation to the axles of the pivoting member  18  in order to move the axis  72  of rotation of its cam portion  54  being pivotally moved. Moreover, the pivoting member  18  is provided at its longitudinal ends with locking portions adapted to engage the housing  12  for the purpose of preventing the pivoting member  18  from being raised (in the direction of height viewed in the drawings) when the pressure receiving portions  32  of said contacts  14  and  16  are urged or pressed. The shape and size of the locking portions may be arbitrary insofar as they can engage the housing  12  and may be suitably designed in consideration of their function described above, the size and strength of the connector, and the like.  
         [0062]     Said cam portion  54  of said pivoting member  18  serves to urge or press said pressure receiving portions  32  of the contacts  14  and  16 , and is preferably of an elongated shape and has a substantially elliptical cross-section in the illustrated embodiment. With such an elliptical cross-section of the cam portion  54 , upon rotation of the cam portion  54  between the pressure receiving portions  32  and the protrusion bases  44  of the connection portions  40  of the contacts  14  and  16 , the pressure receiving portions  32  of the contacts  14  and  16  are raised with the aid of the variation in height of contact points caused by the cross-section of the cam portion  54 , thereby urging the contact portions  26  of the contacts  14  and  16  against the flexible printed circuit board  64 . The shape of the cam portion  54  may be any shape so long as the following functions can be achieved. That is, the cam portion  54  can be rotated between the pressure receiving portions  32  and the protrusion bases  44  of the connection portions  40  of the contacts  14  and  16 , and the pressure receiving portions  32  of the contacts  14  and  16  can be raised with the aid of the variation in height of contact points between the cam portion  54  and the pressure receiving portions  32  caused by the variation in size such as major and minor axes of an ellipse. In addition, the turning force of said pivoting member  18  can be mitigated, and timing can be shifted, by means of the cam angles of the cam portion  54  which are varied for the fifteen contacts as shown in  FIG. 1A . The shape and size of said cam portion  54  may be suitably designed in consideration of these functions. In the illustrated embodiment having eighty contacts, starting from the angle 10°, the angle is varied in increments of 5° for the fifteen contacts. In more detail, the cam portion  54  has the angle 10° for the first to the fifteenth contacts, the angle 15° for the sixteenth to the thirtieth contacts, the angle 20° for the thirty-first to the forty-fifth contacts, the angle 25° for the forty-sixth to the sixtieth contacts, the angle 30° for the sixty-first to the seventy-fifth contacts, and 0° (the standard surface) for the seventy-sixth to the eightieth contacts.  
         [0063]     Moreover, said pivoting member  18  is provided with the actuating portion  56  for improving its operationality. The particular feature of the pivoting member is that the cam portion  54  is pivotally moved between the pressure receiving portions  32  and the protrusion bases  44  of said contacts  14  of the one kind so that the pressure receiving portions  32  of said contacts  14  and  16  of both the kind are raised, thereby bringing the contact portions  26  of said contacts  14  and  16  of both the kinds into contact with the flexible printed circuit board  64 .  
         [0064]     Said pivoting member  18  is formed with the anchoring holes  58  provided independently from one another, into which the projections  42  of said contacts  14  and  16  to resist to the strong reaction forces against the pivotal movement of the pivoting member  18 . By providing the anchoring holes  58  independently from one another, the strength of the pivoting member  18  can be improved to prevent its deformation upon its pivotal movement.  
         [0065]     Said pivoting member  18  is pivotally mounted on said housing  12  on the side opposite from the fitting opening  20 , that is, on the side of the connection portions of the contacts  14  of the one kind. After the contacts  14  and  16  of both the kinds have been fixed in said housing  12 , said pivoting member  18  is inserted from the side of the connection portions  40  of the contacts  14  of the one kind and held.  
         [0066]     The housing  12  will then be explained. The housing  12  is formed from an electrically insulating plastic material by means of the injection molding of the known technique. The materials for the housing may be selected in consideration of dimensional stability, workability, manufacturing cost and the like and generally include polybutylene terephthalate (PBT), polyamide (66PA or 46PA), liquid crystal polymer (LCP), polycarbonate (PC) and the like and combination thereof.  
         [0067]     Said housing  12  is formed with inserting grooves  48  into which a required number of the contacts  14  and  16  are fitted and fixed by press-fitting, hooking (lancing), welding and the like. Moreover, said housing  12  is provided with the fitting opening  20  for inserting said flexible printed circuit board  64  thereinto. The size of said fitting opening  20  may be suitably designed such that said flexible printed circuit board  64  can be inserted into the opening  20  and can be brought into contact with said contacts  14  and  16  by means of the pivoting member  18  after the board  64  has been inserted. Said housing  12  is provided at both the longitudinal ends with the bearings into which the axles of said pivoting member  18  are fitted to be pivotally moved. As described above, the bearings have clearances in relation to said axles of the pivoting member so that the cam portion  54  of said pivoting member  18  can be compactly rotated. The shape and size of the bearings may be arbitrary so long as the pivoting member  18  can be pivotally moved and its cam portion  54  can be compactly rotated, and may be suitably designed in consideration of their functions, strength and size of the housing  12 , and the like.  
         [0068]     Said housing  12  is provided with a ceiling portion  50  for covering the contact portions  26  of said contacts  14  and  16  for the purpose of improving the dust-proof property for said contacts  14  and  16 . The size and shape of the ceiling portion may be suitably designed in consideration of its function, the strength of said housing  12 , pivotal movement capability and strength of said pivoting member  18 , and the like. Thicknesses of said housing  12  are made as thin as possible in order to achieve the reduced overall height of the connector.  
         [0069]     Examples of applications of the invention include connectors using a flexible printed circuit board for use in electric and electronic appliances such as flat-screen televisions, rear projection screens and the like, and more particularly cam structures with variant cam shapes being capable of varying forces and actions to be applied to mating objects.  
         [0070]     While the invention has been particularly shown and described with reference to the preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details can be made therein without departing from the spirit and scope of the invention.