Abstract:
A connector has a housing, a cover for covering the housing. The housing has, a card retention section, a plurality of contacts, a swing slider, and a lock mechanism. The card retention section has a card insertion port for accepting therein a memory card. The contacts face the card insertion port to electrically contact with a distal end side of the memory card. The swing slider is provided to freely swing to an insertion direction of the memory card, and engages with the distal end and a concave section on a side of the memory card to slide with the memory card in an insertion direction, when the memory card is inserted into the card insertion port of the card retention section. The lock mechanism for swinging the swing slider toward inside to retain the memory card when the memory card reaches a proximal end side of the housing.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2003-296730 filed on Aug. 20, 2003, the entire contents of which is incorporated herein by reference. 
   FIELD OF THE INVENTION 
   The present invention relates to a memory card connector for establishing an electrical connection with a memory card exemplified by a miniSD (Secure Digital) card based on the SDA (Standard Card Association) standard through insertion thereof and, more specifically, to a memory card connector with a lock mechanism for retaining a memory card at its inserted position. 
   BACKGROUND OF THE INVENTION 
   A memory card serving as a card storage unit includes flash memory for a storage medium. The memory card is very small in size, and thus consumes very little electricity for data reading and writing. With such advantages, the memory card has been popular especially as recording medium typically for camera-equipped mobile phones and PDAs (Personal Digital Assistances). 
   Compared with disk storage units exemplified by flexible disks (FDs) and magneto-optic disks (MOs), the memory cards are smaller in storage capacity and higher in price. With the recent technological progress and economies of scale in manufacturing observed for devices using memory cards, however, the storage capacity of the memory cards is increased up to about 128 MB, and the price thereof is reduced. 
   Moreover, unlike FDs and MOs, the memory cards require no drive for data reading and writing. With such an advantage, the memory cards are considered preferable as storage media for digital cameras, notebook PCs, and portable music players those placing prime importance on power-thriftiness and portability. 
   The miniSD card has the outer dimensions of 21.55 mm (length)×20 mm (width)×1.4 mm (thickness). On the other hand, the SD card has the outer dimensions of 32.2 mm (length)×24 mm (width)×2.1 mm (thickness). As such, compared with the SD card, the miniSD card is reduced in capacity about 60%. Another difference of the miniSD card from the SD card is the number of connector terminals provided on the surface, i.e., 11 pins for the miniSD card and 9 pins for the SD card. 
   For data reading and writing from/to such a memory card, a memory card connector has appeared in the market to serve as a connector for the purpose. The memory card connector is provided with a lock mechanism to prevent a memory card inserted into a housing from being detached or pulled out. As an example, refer to JP-A-2003-86296. 
   The above memory card connector includes the housing, a shield plate which is attached as to cover the housing upper surface and both side surfaces, the lock mechanism for locking the inserted memory card, and a connector pin retention section formed in one piece with the housing. The lock mechanism includes a lock member which is provided for engaging with the memory card inserted into a memory card insertion section to lock the memory card at its predetermined insertion position, a slider for supporting the lock member, an ejection coil spring for biasing the slider in the pull-out direction, and a lock pin which is provided for engaging with a heart cam formed to the slider to latch the slider at its attachment position. 
   The problem with such a conventional memory card connector is that when the coil spring is increased in compressive strength to pull out the memory card against the friction force between the memory card and a plurality of connector pins (contact terminals) which is making contact with terminals of the memory card, the memory card might pop out from the memory card connector. 
   SUMMARY OF THE INVENTION 
   To solve such problems, an object of the present invention is to provide a memory card connector capable of preventing a memory card from popping out therefrom. 
   To achieve such an object, the inventor accordingly invented a new connector as below. 
   A first aspect of the present invention is directed to A connector comprising, a housing, a cover for covering the housing, and wherein the housing includes, a card retention section of substantially a box shape having a card insertion port for accepting therein a memory card, a plurality of contacts which faces the card insertion port to electrically contact with a distal end side of the memory card, a swing slider which is provided to freely swing in a direction substantially orthogonal to an insertion direction of the memory card, and engages with the distal end and a concave section on a side of the memory card to slide with the memory card in an insertion direction when once the memory card is inserted into the card insertion port of the card retention section, and a lock mechanism for swinging the swing slider toward inside to retain the memory card when the memory card reaches a proximal end side of the housing. 
   According to a second aspect of the present invention, the connector according to the first aspect of the present invention, wherein the swing slider has a cam channel of a heart shape, wherein the lock mechanism includes a biasing member for biasing the swing slider toward inside of the card retention section and a guide rod engaged with the cam channel of the swing slider, and whereby the guide rod moves along the cam channel, and the swing slider is pulled by the biasing member and moves toward the card insertion port while engaging with the concave section and the distal end of the memory card when the memory card in a retained state is pushed in the insertion direction. 
   According to a third aspect of the present invention, the connector according to first or second aspect of the present invention, wherein the swing slider is provided with a first lug to be latched at the distal end of the memory card, and a second lug for engaging with the concave section of the memory card. 
   According to a fourth aspect of the present invention, the connector according to second or third aspect of the present invention, wherein a bottom surface of the cam channel is changed in level to prevent the guide rod from moving in a reverse direction, and wherein the cover includes a pressing piece for biasing the guide rod to the bottom surface of the cam channel. 
   According to a fifth aspect of the present invention, the connector according to any one of first to fourth aspect of the present invention, wherein the memory card is a mini SD card. 
   The memory card is formed by housing a memory chip in a card-shaped case. The memory card is provided with a storage unit including connector terminals on one side thereof. The memory card includes a miniSD card, an SD card, or a memory stick card. 
   The housing may be formed by an insulative synthetic resin material. The cover is preferably formed by a metal plate in contemplation of shielding the memory card. 
   The contact is a leaf spring contact, and can be a cantilever. 
   According to the present invention, when a memory card is inserted into the connector, the second lug abuts the side surface of the memory card. When the memory card is pushed further, the second lug slides in contact along the side surface of the memory card, then the second lug is engaged with the concave section thereof. At the same time, the first lug is engaged with the distal end of the memory card. Then, when the memory card is pushed still further, the swing slider moves toward the proximal end of the housing together with the memory card. Then, the guide rod moves in the heart cam channel so that the swing slider moves inward against the biasing member. Thereafter, one end of the guide rod is latched by the heart cam channel, and thus the swing slider retains the memory card. 
   When the memory card in the retained state is pushed in the insertion direction, the guide rod moves along the cam channel, and as a result, the swing slider moves toward the outside. In response thereto, the first lug also moves toward the outside so that the memory card is released and thus is not retained any more. Thereafter, the swing slider is pulled by the biasing member, and moves toward the card insertion port while engaging with the concave section and the distal end of the memory card. 
   With such a structure, during when the memory card is moving toward the card insertion port, the second lug remains engaged with the concave section of the memory card. Accordingly, the memory card is not accidentally popped out from the connector. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective external view of an exemplary memory card connector of the present invention. 
       FIG. 2  is a perspective external view of a connector  100  of the present invention with its cover removed. 
       FIG. 3  is a perspective external view of the cover of the present invention. 
       FIG. 4  is a perspective external view of a housing of the present invention. 
       FIG. 5  is a perspective external view of a swing slider of the present invention viewed from the surface side thereof. 
       FIG. 6  is a perspective external view of the swing slider of the present invention viewed from the back side thereof. 
       FIG. 7  is a perspective external view of a guide rod of the present invention. 
       FIG. 8  is a plan view of the memory card connector of the present invention, showing the state before a memory card is inserted thereinto. 
       FIG. 9  is a plan view of the memory card connector of the present invention, showing the state after the memory card is inserted thereinto, and the slanting section of the side surface of the memory card is abutting a slope section of a second lug. 
       FIG. 10  is a plan view of the memory card connector of the present invention, showing the state that the side surface of the memory card is pushing up the second lug against the biasing force of a tensile coil spring. 
       FIG. 11  is a plan view of the memory card connector of the present invention, showing the state that the second lug is engaged with the concave section. 
       FIG. 12  is a plan view of the memory card connector of the present invention, showing the state that the memory card is inserted thereto. 
       FIG. 13  is a plan view of the memory card connector of the present invention, showing the change from the state of  FIG. 12 . 
       FIGS. 14A to 14E  are all a diagram for illustrating the action of the swing slider of the present invention including a cam channel of a heart shape. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   In the below, the most preferred embodiment of the present invention is described by referring to the accompanying drawings. 
     FIG. 1  is a perspective external view of an exemplary memory card connector (hereinafter, simply referred to as connector) of the present invention. In  FIG. 1 , a connector  100  is provided with a housing  1 , and a cover  2  covering the housing  1 . 
   In  FIG. 1 , the housing  1  is formed rectangular using an insulative synthetic resin material. The cover  2  is made from a metal plate, and both blades thereof are bent into L-shape. The cover  2  is so attached as to cover the housing  1 . 
   Through attachment of the cover  2  to the housing  1 , the connector  100  is formed with a card insertion section  1 A, and a thin card retention section  1 B of a rectangular parallelepiped, wherein the card insertion section  1 A accepts a memory card  10  inserted thereinto. A plurality of cantilever contact  3  is provided, and arranged to the housing  1  at positions where opposed to the card insertion section  1 A. With this structure, the cantilever contacts  3  are to be electrically contacted with connector terminals (not shown) on the surface of the memory card  10 . 
     FIG. 2  is a perspective external view of the connector  100  with the cover  2  of  FIG. 1  removed. As shown in  FIG. 2 , a top-open concave section  11  serving as a card retention section includes guide walls  11 A and  11 B opposing to each other with a space therebetween slightly wider than the width of the memory card  10 . These guide walls  11 A and  11 B restrict the width of the memory card  10 , thereby allowing positioning the connector terminals on the memory card  10  and the cantilever contacts  3 . 
   As shown in  FIG. 2 , the cantilever contacts  3  are each a leaf spring contact, and can be a cantilever. These cantilever contacts  3  are arranged in the direction orthogonal to the insertion direction of the memory card  10 . 
   The cantilever contacts  3  are placed on the side of a stop wall  12  locating closer to the tail ends of the connector terminals arranged on the memory card  10 . Specifically, elastic sections  3 A of the cantilever contacts  3  are opposed to the card insertion port  1 A (refer to  FIG. 1 ), and each of fixation sections  3 B of the cantilever contacts  3  form a junction tab  3 C by their ends extending rearward of the stop wall  12  for soldering joint. 
   As shown in  FIG. 2 , a lock mechanism  1 R of the connector  100  includes a swing slider  4 , which is placed on one planar side of the top-open concave section  11 . The swing slider  4  is biased by a tensile coil spring  5  as a biasing member toward the opposite direction from the insertion direction of the memory card  10 . 
   On the planar side of the top-open concave section  11 , a first guide  13  of a square column extends from the side of the stop wall  12  of the housing  1  toward the side of the card insertion port  1 A (refer to  FIG. 1 ). At the tail end of the first guide  13 , a cylindrical protrusion  13 A is formed. 
   Moreover, the planar side of the top-open concave section  11  is formed with a second guide  14  of a square column to be parallel with the first guide  13 . Compared with the first guide  13 , the second guide  14  is placed closer toward the center of the top-open concave section  11 . 
   Moreover, referring to  FIG. 2 , the swing slider  4  is formed thereon with a cam channel  4 A of a heart shape. This heart cam channel  4 A is coupled to one end of the guide rod  6 . The other end of the guide rod  6  is retained on the side of the stop wall  12  to freely rotate. The swing slider  4  and the guide rod  6  follow the trail of the heart cam channel  4 A for relative displacement. 
   The swing slider  4  includes a first lug  41  which abuts the corner part of the memory card  10  on the insertion side. The swing slider  4  also includes a second lug  42  that is to be latched with the concave section  10 A formed on the side surface of the memory card  10 . The second lug  42  protrudes from the top-open concave section  11  to abut the side surface of the memory card  10  when the memory card  10  is inserted into the card retention section  1 B. 
   On the side of the guide wall  11 B of  FIG. 2 , a card detection switch  7  is provided to electrically detect whether the memory card  10  is correctly placed at its insertion position. The card detection switch  7  is formed by a movable plate  7 A and a fixed plate  7 B. 
   As shown in  FIG. 2 , the movable plate  7 A is partially bent, and the bending section is extended from the side of the guide wall  11 B. When the memory card  10  is correctly placed at its insertion position, the bending section of the movable plate  7 A is pushed toward the side surface part of the memory card  10 , and thus the tail end thereof abuts the fixed plate  7 B. That is, the movable plate  7 A and the fixed plate  7 B are electrically connected to each other. 
   Once the memory card  10  is ejected from the connector  100 , the bending section of the movable plate  7 A returns to its original position so that the electrical connection established between the movable plate  7 A and the fixed plate  7 B is cut off. Herein, the tail ends of the movable plate  7 A and the fixed plate  7 B are connected to a card detection circuit of a printed circuit onto which the connector  100  is incorporated. 
     FIG. 3  is a perspective external view of the cover  2 . By referring to  FIG. 3 , a pair of pressing pieces  2 A and  2 B are formed on the upper surface of the cover  2  with such a certain space therebetween as not to erase any printed letters or others on the memory card  10 . These pressing pieces  2 A and  2 B press the memory card  10  of  FIG. 2  toward the top-open concave section  11 . 
   By referring to  FIG. 3 , another pressing piece  2 C is formed to the rear part of the upper surface of the cover  2 . This pressing piece  2 C is provided for pressing the guide rod  6  of  FIG. 2  toward the bottom surface of the heart cam channel  4 A. Also to the rear part of the upper surface of the cover  2 , a window  2 D is provided to check the cantilever contacts  3  of  FIG. 2 , i.e., their contact state. 
     FIG. 4  is a perspective external view of the housing  1 . As shown in  FIG. 4 , the first guide  13  and the second guide  14  are both protruding from the bottom surface of the top-open concave section  11  so as to be one piece with the housing  1 . 
   At the rear end of the second guide  14 , a shaft hole  14 A is drilled to couple, through rotation, with the end part of the guide rod  6  of  FIG. 2 . To the side of the guide wall  11 A, formed is a stepped groove  11 C for latching the hook of the tensile coil spring  5  of  FIG. 2 . 
     FIG. 5  is a perspective external view of the swing slider  4  viewed from the surface side thereof. As shown in  FIG. 5 , on the left side of the swing slider  4 , the heart cam channel  4 A is formed. The vertex of the cam groove  4 A has a V-shaped groove  4 V. Here, the bottom surface of the cam channel  4 A is changed in level so that the guide rod  6  (refer to  FIG. 2 ) does not trail in the reverse direction. The details thereof are left for later description. 
   From the right side surface of the swing slider  4 , the first lug  41  is protruding. With the right side surface of the swing slider  4  and the first lug  41 , an L-shaped latch groove is so formed as to match in shape with the corner part of the memory card  10  on the insertion side. 
   From the right upper side surface of the swing slider  4 , the second lug  42  protrudes. To securely latch with the rectangular concave section  10 A (refer to  FIG. 2 ) on the memory card  10 , one corner part of the second lug  42  is formed to have a 90-degree angle. The other corner part of the second lug  42  is sloped to facilitate the slide-coupling with the side surface of the memory card  10 . 
   By referring to  FIG. 5 , the upper part of the swing slider  4  is formed with a stepped groove  43 , which latches the hook of the tensile coil spring  5  of  FIG. 2 . 
     FIG. 6  is a perspective external view of the swing slider  4  viewed from the back side thereof. As shown in  FIG. 6 , a countersunk long hole  4 B is formed at the bottom surface of the swing slider  4 . The countersunk long hole  4 B is provided to guide the cylindrical protrusion  13 A (refer to  FIG. 4 ) formed to the first guide  13  (refer to  FIG. 4 ). At the end part of the countersunk long hole  4 B, a groove  40 B is formed to slide-couple with the first guide  13 . The groove  40 B is open tapered toward its tail end. 
   By referring to  FIG. 6 , at the bottom surface of the swing slider  4 , a concave section  4 C is formed to slide-couple with the second guide  14  (refer to  FIG. 4 ) to freely swing. The concave section  4 C is also open tapered toward its tail end as is the groove  40 B. 
     FIG. 7  is a perspective external view of the guide rod  6 . As shown in  FIG. 7 , the guide rod  6  has such a shape that both ends thereof are bent to each have a 90-degree angle. As such, the guide rod  6  has two bending shafts  6 A and  6 A, and one of the bending shafts  6 A serves as a follower member of the heart cam channel  4 A of  FIG. 2 , and the other bending shaft  6 A is engaged with the shaft hole  14 A of  FIG. 4 . 
   The guide rod  6  can freely swing about the shaft hole  14 A, and a middle shaft section  6 B thereof is pressed against the pressing piece  2 C of  FIG. 3 . 
   The operation of attaching/detaching the memory card  10  to/from the connector  100 , and the operation of the lock mechanism  1 R are as will hereinafter be described in detail. 
     FIG. 8  is a plan view of the connector  100  before attached with the memory card  10 . In  FIG. 8 , the swing slider  4  is biased by the tensile coil spring  5  in the direction of arrow R. 
   In  FIG. 8 , the swing slider  4  does not move any further in the direction of arrow R because the guide rod  6  is latched into the heart cam channel  4 A. The second lug  42  of the swing slider  4  is so placed as to protrude from the guide wall  11 A to abut the side surface of the memory card  10 . 
     FIG. 9  is a view of the connector  100 .  FIG. 9  shows the state in which the memory card  10  is inserted into the connector  100 , and the slanting section of the memory card  10  on its side surface is abutting the slope section of the second lug  42 . 
   Under the state of  FIG. 9 , the corner part of the memory card  10  on the insertion side is not abutting the first lug  41 . Herein, the memory card  10  is inserted into the connector  100  in such a manner that the connector terminals come upside. 
   From the state of  FIG. 9 , when the memory card  10  is inserted a little in the direction of arrow F, the slanting section of the memory card  10  on its side surface slides over the slope section of the second lug  42 . Thereafter, the connector  100  will be in the state of  FIG. 10 . 
     FIG. 10  is a plan view of the connector  100 .  FIG. 10  shows the state in which the side surface of the memory card  10  is pushing up the second lug  42  against the biasing force of the tensile coil spring  5 . In the process of state change from  FIG. 9 to 10 , the swing slider  4  is rotating counter clockwise about the cylindrical protrusion  13 A (refer to  FIG. 4 ) formed to the first guide  13 . 
   From the state of  FIG. 10 , when the memory card  10  is inserted a little more into the direction of arrow F against the biasing force of the tensile coil spring  5 , the connector  100  will be in the state of  FIG. 11 . 
     FIG. 11  is a plan view of the connector  100 . In the process of state change from  FIG. 10 to 11 , the second lug  42  engages with the concave section  10 A by sliding over the slanting section of the memory card  10  on its side surface. In  FIG. 11 , the corner part of the memory card  10  on the insertion side is abutting the first lug  41 . 
   In the state of  FIG. 11 , the swing slider  4  rotates clockwise by the biasing force of the tensile coil spring  5 , and returns to the same position and posture as  FIG. 9 . If the memory card  10  is inserted a little more in the direction of arrow F against the biasing force of the tensile coil spring  5 , it will result in the insertion state of  FIG. 12 . 
     FIG. 12  is a plan view of the connector  100 . In the process of state change from  FIG. 11 to 12 , the swing slider  4  moves parallel following the first and second guides  13  and  14 . Then, the swing slider  4  follows the movement of the memory card  10  to be inserted. 
   In  FIG. 12 , one bending shaft  6 A of the guide rod  6  is moving toward the V-shaped groove  4 V formed to the heart cam channel  4 A. The swing slider  4  is biased to move in the direction of arrow R by the tensile coil spring  5 . However, the swing slider  4  is fixed in position due to the guide rod  6  latched into the V-shaped groove  4 V. 
     FIG. 12  shows the insertion state of the memory card  10 . In this insertion state, the connector terminals on the memory card  10  are contacting with the cantilever contacts  3 , thereby allowing data reading and writing from/to the memory card  10 . The second lug  42  is engaging with the concave section  10 A, and thus the memory card  10  is not easily popped out from the connector  100  even with vibration if occurred. With such a lock mechanism  1 R of the present invention, the memory card  10  can favorably remain inserted. 
   From the state of  FIG. 12 , when the memory card  10  is inserted a little more in the direction of arrow F against the biasing force of the tensile coil spring  5 , one bending shaft  6 A of the guide rod  6  is released from the V-shaped groove  4 V, and moves to the trail on the left side of the backward stroke. 
   Then, the memory card  10  moves in the direction of arrow R by the biasing force of the tensile coil spring  5 , and is put into the state of  FIG. 13 . That is, by being pushed toward the first lug  41 , the memory card  10  moves in the not-insertion direction, that is, in the ejection direction. 
     FIG. 13  is a plan view of the connector  100 . In  FIG. 13 , the position relationship between the connector  100  and the memory card  10 , and the state of the lock mechanism  1 R are both put back to the same as those of  FIG. 1 . Even moved, the memory card  10  never accidentally pop out from the connector  100 , because the second lug  42  remains engaged with the concave section  10  of the memory card  10 . 
   As shown in  FIG. 10 , the second lug  42  biased by the tensile coil spring  5  pulls the card memory  10  with such a strong force as sliding over from the concave section  10 A. Thus, after the state of  FIG. 9 , the memory card  10  can be ejected from the connector  10 . 
   By referring to  FIGS. 14A to 14E , described next is the action of the swing slider  4  including the heart cam channel  4 A. Specifically,  FIG. 14A  is a plane view of the swing slider  4 , and  FIG. 14B  is a cross sectional view cut along a B—B line of  FIG. 14A .  FIG. 14C  is a cross sectional view cut along a C—C line of  FIG. 14A .  FIG. 14D  is a cross sectional view cut along a D—D line of  FIG. 14A . And  FIG. 14E  is a cross sectional view cut along an E—E line of  FIG. 14A . 
   The cam system includes the swing slider  4  provided with the heart cam channel  4 A as a cam serving as a moving member, and the guide rod  6  (refer to  FIG. 2 ) as a follower member. The moving member and the follower member of the cam system relatively change in position. 
   In the present embodiment, the point where the swing slider  4  and the guide rod  6  are contacting will draw a plane curve, i.e., trail of heart. This contact point also draws a space curve of the continuous trail of the cam channel  4 A whose bottom surface is changed in level or sloped. The swing slider  4  and the guide rod  6  are structuring a so-called three-dimensional cam system. 
   As shown in  FIG. 14 , from a bottom surface A 1 , the cam channel  4 A starts to trail by the bending shaft  6 A of the guide rod  6 , and the bottom surface A 1  is a plane parallel to the bottom surface of the swing slider  4 . A bottom surface A 2  is sloped upward from the bottom surface A 1 . 
   After the bending shaft  6 A passes the sloped bottom surface A 2 , the bending shaft  6 A reaches a bottom surface A 3  locating upper than the bottom surface A 1 . After the bending shaft  6 A passes the bottom surface A 3 , the plane is changed in level, and the bending shaft  6 A reaches a bending bottom surface  4 A locating lower than the bottom surface A 3 . That is, in the process of state change from  FIG. 11 to 12 , i.e., in the process that the bending shaft  6 A (refer to  FIG. 12 ) of the guide rod  6  moves, once reached the bottom surface A 4 , the bending shaft  6 A cannot return therefrom to the bottom surface A 3 . 
   By referring to  FIG. 14 , after the bending shaft  6 A passes the bottom surface A 4 , the plane is changed in level again, and the bending shaft  6 A reaches a bottom surface A 5  locating lower than the bottom surface A 4 . A groove formed to the bottom surface A 4  and another groove formed to the bottom surface A 5  form the V-shaped groove  4 V. 
   In the process of state change from  FIG. 11 to 12 , i.e., in the process that the bending shaft  6 A (refer to  FIG. 11 ) of the guide rod  6  moves, once reached the bottom surface A 5 , the bending shaft  6 A of the guide rod  6  is not allowed to return therefrom to the bottom surface A 4 . Once the bending shaft  6 A reaches the V-shaped groove  4 V, it will be locked or attached as shown in  FIG. 12 . Here, the trail of the bending shaft  6 A from the bottom surface A 1  to A 5  may be referred to as “forward stroke”. 
   Thereafter, as described by referring to  FIG. 12 , when the memory card  10  is inserted a little more in the direction of arrow F against the biasing force of the tensile coil spring  5 , one bending shaft  6 A of the guide rod  6  is released from the V-shaped groove  4 V, and moves to the trail on the left side of the backward stroke. 
   By referring to  FIG. 14 , when the bending shaft  6 A passes the bottom surface A 5 , the plane is changed in level, and the bending shaft  6 A reaches a bottom surface A 6  locating lower than the bottom surface A 5 . That is, in the trail of the backward stroke, after reaching the bottom surface A 6 , the bending shaft  6 A (refer to  FIG. 12 ) is not allowed to return therefrom to the bottom surface A 5 . 
   By referring to  FIG. 14 , adjacent to the bottom surface A 6 , formed is a bottom surface A 7  that is sloped upward from the bottom surface A 6 . Once the bending shaft  6 A passes the sloped bottom surface A 7 , the bending shaft  6 A reaches a bottom surface A 8  locating upper than the bottom surface A 6 . After the bending shaft  6 A passes the bottom surface A 8 , the plane is changed in level, and the bending shaft  6 A returns to the bottom surface A 1  locating lower than the bottom surface A 8 . 
   As such, the contact point between the cam channel  4 A and the guide rod  6  (refer to  FIG. 2 ) draws a planar trail of a heart, and in the height direction, draws a trail partially irreversible. 
   According to the present invention, a second lug remains engaged with the concave section of the memory card, so that the second lug prevent a memory card from accidentally popping out from a connector on the way toward a card insertion port for ejection from the connector. With such a structure, the memory card can be ejected with reliability.