LOW PROFILE MEMORY CARD CONNECTOR
FIELD OF THE INVENTION This invention generally relates to the art of electrical connectors and, particularly, to a memory card connector.
BACKGROUND OF THE INVENTION Memory cards are known in the art and contain intelligence in the form of a memory circuit or other electronic program. Some form of card reader reads the information or memory stored on the card. Such cards are used in many applications in today's electronic society, including video cameras, digital still cameras, smartphones, PDA's, music players, ATMs, cable television decoders, toys, games, PC adapters, multi-media cards and other electronic applications. Typically, a memory card includes a contact or terminal array for connection through a card connector to a card reader system and then to external equipment. The connector readily accommodates insertion and removal of the card to provide quick access to the information and program on the card. The card connector includes terminals for yieldingly engaging the contact array of the memory card. The memory card, itself, writes or reads via the connector and can transmit between electrical appliances, such as a word processor, personal computer, personal data assistant or the like. The card may be used in applications such as mobile or cellular telephones which are actuated and permit data access after identifying an identification code stored on a SIM (subscriber identification module) card. The SIM card has a conductive face with an array of contacts, and the mobile phone has a SIM card connector with terminals for electrical connection with the contacts of the SIM card to ensure the subscriber identification confirmation. A typical memory card connector includes some form of dielectric housing which is covered by a metal shell. The metal shell may be stamped and formed of sheet metal material and formed substantially into a box-shape. The metal shell and the housing combine to define a card-receiving cavity. One end of the cavity is open to form a card- insertion opening. The dielectric housing may be generally L-shaped or U-shaped and includes a rear terminal-mounting section at the rear of the cavity, and at least one longitudinal side wall section extends forwardly from one or both ends of the rear section
at one or both sides of the cavity. The metal shell has a top plate substantially covering the dielectric housing, with side plates extending downwardly over the side wall sections of the housing. One or both of the side wall sections of the housing define the sides of the card-receiving cavity. An example of this type of memory card connector is shown in Japanese Patent Laid-Open No. 2002-329553. Some card connectors include a card eject mechanism whereby the memory card is simply inserted into the connector, and the eject mechanism is used to facilitate removal of the card from the connector. Some eject mechanisms include slider members which engage the memory card for movement therewith into and out of the connector. Latches, cams, eject devices and other operative components then are operatively associated with the slider rather than the memory card itself. An example of a memory card connector with a "push/push" type eject mechanism is shown in Japanese Patent Laid-Open No. 2002-343468. Such electrical appliances as video cameras, digital cameras, cellular telephones, PDA's and other small-sized electronic devices have been remarkably decreasing in size. Many such miniaturized devices are equipped with push/push or other types of card eject mechanisms which also must be miniaturized in order to maintain a low profile for the connector. The dielectric housing of the connector, however, makes it quite difficult to reduce the size of the card connector, particularly the height of the connector. The dielectric housing typically is molded of insulative plastic material and includes a floor plate or wall which is relatively large in area but cannot be reduced in thickness below a certain limit (approximately 0.2 millimeters) within the limitations of an ejection molded process. Reducing the size and/or height of the dielectric housing further is limited because the eject mechanism is mounted on the housing, such as on a longitudinal side wall section of the housing which also cannot be reduced in size within fabrication limitations. The present invention is directed to solving these problems and allowing a memory card connector to be provided with a reduced size and particularly a very low profile. SUMMARY OF THE INVENTION An object, therefore, of the invention is to provide a new and improved, low profile memory card connector.
In the exemplary embodiment of the invention, the connector includes a metal shell having a top wall and at least one generally L-shaped side wall depending along a side edge of the top wall to at least in part define a card-receiving cavity for receiving a memory card. An insulative housing is provided at a rear of the cavity and mounts a plurality of conductive terminals which have contact portions extending forwardly into the cavity for engaging appropriate contacts on the memory card. A card eject mechanism is provided for ejecting the memory card from the cavity. The card eject mechanism is located in an inner space defined by the L-shaped side wall of the metal shell. According to one aspect of the invention, the metal shell includes a pair of the L- shaped side walls depending along opposite sides edges of the top wall and defining opposite sides of the card-receiving cavity. The insulative housing comprises an elongated terminal block which extends along a rear edge of the top wall of the metal shell between the side walls of the shell. The one L-shaped side wall includes a guide rail for guiding movement of the card eject mechanism. According to another aspect of the invention, the card eject mechanism includes a slider engageable with the memory card for movement with the card into and out of the cavity. The slider is movably mounted within the inner space of the one L-shaped side wall. According to a further aspect of the invention, the slider includes a cam slot and the eject mechanism includes a cam pin operatively associated with the cam slot. A card-insertion guide piece is mounted at a front end of the one L-shaped side wall at one side of a front insertion opening of the cavity. One end of the cam pin is caught by the cam slot in the slider, and an opposite end of the cam pin is fixed to the card-insertion guide piece. Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals
identify like elements in the figures and in which: FIG. 1A is a top perspective view of a memory card connector embodying the concepts of the invention, with a memory card shown inserted into the connector; FIG. IB is a perspective view looking at the bottom of FIG. 1; FIG. 2 is a bottom perspective view of the connector, with the memory card removed; FIG. 3 is a top perspective view of the metal shell of the connector; FIG. 4 is a perspective view of the card-insertion guide piece; FIG. 5 is a perspective view of the elongated terminal block; FIG. 6 is an enlarged, fragmented perspective view of one side of the connector, with the metal shell removed to show the card eject mechanism; FIG. 7 is a fragmented, top perspective view of a portion of the connector showing the card eject mechanism and a memory card in an initial position of insertion; FIG. 8 is a view similar to that of FIG. 7, with the memory card in its extreme inserted position; FIG. 9 is a view similar to that of FIGS. 7 and 8, with the memory card in its locked/connected position; and FIG. 10 is a view similar to that of FIGS. 7-9, with the memory card being pushed back to its extreme inserted position and the card eject mechanism about to be released to eject the card.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings in greater detail, and first to FIGS. 1A-2, the invention is embodied in a memory card connector, generally designated 12, which includes a metal shell, generally designated 14, and an insulative housing, generally designated 16, which mounts a plurality of terminals, generally designated 18. A card eject mechanism, generally designated 20, is mounted within one side of the metal shell, and a card- insertion guide piece, generally designated 22, is mounted within one front corner of the metal shell. A memory card, generally designated 24, is insertable into the connector in the direction of arrow "C" (FIG. 1A). More particularly, referring to FIG. 3 in conjunction with FIGS. 1 A-2, metal shell 14 is stamped and formed of thin sheet metal material. The metal shell defines a card- receiving cavity, generally designated 26 (FIG. 2), for receiving memory card 24. The
metal shell includes a top plate or wall 28 and a pair of generally L-shaped side walls 30 and 32 depending along opposite side edges of the top wall and combining therewith to define the top and sides of cavity 26. The cavity has a front insertion opening 34. As best seen in FIGS. IB and 2, the L-shaped side wall 30 has a vertical section 30a bent at a right-angle to top wall 28, and a horizontal bottom section 30b bent at a right angle to the vertical section and extending inwardly therefrom. A bottom-section guide piece 30c is formed at a front end of side wall 30 to guide memory card 24 into cavity 26. Side wall 30 has a stamped and formed mounting flange 30d which projects outwardly for securing the metal shell to a mounting pad on a printed circuit board, as by soldering. Finally, a window 30e is formed in side wall 30 at a rear end thereof. Similarly, the L-shaped side wall 32 includes a vertical wall section 32a bent at a right-angle along an edge of top wall 28 of the metal shell. A horizontal bottom section 32b is bent at a right angle to the vertical section and extends inwardly therefrom. A mounting flange 32c is stamped and formed out of the side wall for mounting to the printed circuit board. An elongated guide rail 32d is stamped and formed out of horizontal section 32b of the L-shaped side wall 32. The guide rail projects upwardly from the horizontal section for guiding a slide member of eject mechanism 20 as will be described hereinafter. As best seen in FIG. 2, an engagement flange 36 is bent downwardly at the rear of the metal shell. The engagement flange has an engagement opening 36a, along with a mounting flange 36b for mounting to the printed circuit board. As best seen in FIG. 3, an engagement flange 38 is bent downwardly at the front of the metal shell inside side wall 32. Finally, a resilient leaf spring 40 is stamped and formed out of top wall 28 of the metal shell, immediately inside side wall 32. Referring to FIG. 4 in conjunction with FIGS. 1A-3, guide insertion piece 22 is mounted inside the front end of the L-shaped side wall 32 of metal shell 14 at one side of front insertion opening 34. Engagement flange 38 (FIG. 3) which depends from top wall 28 of the metal shell, is press-fit into a catch hole 22a (FIG. 4) in the top of the guide piece which may molded of plastic material. A cam pin engagement hole 22b also is formed in the top of the guide piece, for purposes described hereinafter. Finally, the guide piece has an inwardly directed guide plate 22c which is contiguous with bottom wall 32b of side wall 32, whereby memory card 24 is guided into cavity 26 by guide plate 22c and a chamfered inside surface 22d of the card-insertion guide plate 22.
Referring to FIG. 5 in conjunction with FIGS. 1A-2, dielectric housing 16 is a one-piece structure molded of plastic material or the like in the form of an elongated terminal block which mounts terminals 18. The terminals are mounted within a plurality of through holes 16a in the terminal block. The terminals have contact portions 18a which are cantilevered forwardly into cavity 26 for engaging appropriate contacts on memory card 24. The terminals have tail portions 18b (FIGS. IB and 2) for connection, as by soldering, to appropriate circuit traces on the printed circuit board. Tail portions 18b of the terminals are coplanar with mounting flanges 30d, 32c and 36b of the metal shell for simultaneous soldering to the circuit board. The terminal block has an engagement boss 16b at one end thereof for engagement within window 30e of side wall 30 of the metal shell, as seen in FIG. 2. The terminal block has a rear engagement boss 16c (FIG. 2) for engagement within opening 36a of engagement flange 36 of the metal shell. FIG. 5 shows that the terminal block has an abutment wall 16d at one end thereof, with a spring keeper boss 16e projecting forwardly from the abutment wall. In essence, elongated terminal block 16 is mounted between the side walls of metal shell 14, spanning the side walls of the shell, and forming the rear of card-receiving cavity 26. Referring to FIG. 6, card eject mechanism 20 is fitted into an inner space defined by the L-shaped side wall 32 (FIG. 2) of metal shell 14. The card eject mechanism is of a push/push type as is known in the art and includes a cam slider 44, a coil spring 46 and a cam pin 48. The slider has a slide slot 44a which receives guide rail 32d to guide movement of the slider in a front-to-rear direction as indicated by double-headed arrow "D". Coil spring 46 is positioned over spring keeper boss 16e (FIG. 5) of terminal block 16 and constantly biases the slider in a forward or eject direction indicated by arrow "E". The slider moves back and forth on top of horizontal section 32b of the side wall of the metal shell. It can be seen in FIG. 6 that the horizontal section of the side wall can be of a substantial size or area and not increase the height profile of the connector because the sheet metal material from which the shell is stamped and formed, is quite thin. The slider has an angled surface 44b which engages an angled polarizing edge of memory card 24. The slider has an arm 44c which projects forwardly and terminates in a hook portion 44d which engages in a side edge of the memory card whereby, when the card is inserted into cavity 26, the hook portion "snaps" into engagement with the card recess and the card and slider 44 move in unison within the connector. Cam pin 48 has a forward end fixed within the cam pin engagement hole 22b of the card-insertion guide
piece 22. An opposite end of the cam pin is inserted into and is operatively associated with a heart-shaped cam slot in the top of slider 44, as will be seen below. FIGS. 7-10 show the operation of card eject mechanism 20 as memory card 24 is inserted into and ejected from connector 12. But first, FIG. 7 shows that memory card 24 has a recess 50 in a side edge thereof for receiving hook portion 44d of slider 44 and for conjoint movement of the memory card with the slider. The memory card has a plurality of contacts 52 recessed in the top of the card along a leading edge of the card, for engaging the forwardly cantilevered contact portions 18a of terminals 18. One corner of the card has an angled polarizing surface 54 for engaging angled surface 44b of slider 44. The slider has a heart-shaped cam slot 56 in the top thereof, as is known in the art, for receiving one end 48a of cam pin 48. An opposite end 48b of the cam pin is inserted into hole 22b of guide piece 22, as described hereinafter. Leaf spring 40 (FIG. 3) which is stamped and formed out of top wall 28 of metal shell 14 pushes downwardly on the cam pin and maintains the cam pin in its operative position as shown in FIG. 7. FIG. 7 shows memory card 24 inserted into connector 12 in the direction of arrow
"C" to an initial position of insertion. It can be seen that contacts 52 on the memory card are not yet engaged with contact portions 18a of terminals 18. However, hook portion 44d of slider 44 has resiliently "snapped" into recess 50 in the side edge of the memory card. Therefore, the memory card and the slider are joined for conjoint movement further into the connector. FIG. 8 shows memory card 24 and cam slider 44 having been inserted in the direction of arrow "C" to an extreme inserted position of the memory card, whereat the leading edge of the card abuts against terminal block 16. This sometimes is called a state of being over-inserted to allow the heart-shaped cam slot 56 to operationally position cam pin 48 as is known in the art. After memory card 24 is inserted to its extreme inserted position shown in FIG. 8, the card is released, whereupon coil spring 46 pushes slider 44 and the memory card back forwardly in the direction of arrow "E" to a locked/connected position shown in FIG. 9. In this position, the one end 48a of cam pin 48 catches within a portion of the heart-shaped cam slot 56 to hold the slider and the memory card in this locked/connected position whereat contacts 52 are maintained in engagement or connected to contact portions 18a of terminals 18.
When it is desired to eject memory card 24 form the connector, the card again is pushed inwardly in the direction of arrow "C" in FIG. 10 so that the card moves back to its extreme inserted position. During this second pushing operation, the one end 48a of cam pin 48 is moved out of its catching position within cam slot 56 and is now free to move lengthwise within the slot. Coil spring 46 then becomes operational to push slider 44 and memory card 24 back outwardly in the direction of arrow "F" (FIG. 10) to the initial position of insertion as shown in FIG. 7. The card then can be removed from the connector. It can be seen from the above that card eject mechanism 20 is fully operational as in the prior art, but the eject mechanism is not mounted on any bulky portions of the connector, such as on bulky side wall sections of a dielectric molded plastic housing. The eject mechanism of the invention is mounted entirely within an inner space of the L- shaped side wall 32 of metal shell 14. Like the entire metal shell, the side wall is stamped and formed of thin sheet metal material and takes up little space in a vertical direction because of the thinness of the metal material, itself. Therefore, the height profile of the connector can be reduced significantly. In fact, the width of the connector is significantly reduced because there are no side wall sections whatsoever of any bulky dielectric or plastic housing. It will be understood that the invention may be embodied in other specific forms without departing from the spirit or central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein.