Chip or smart card reader

A contact element support for a smart card reader having a card support surface, a plurality of chambers formed in the contact element support in the area of the card support surface, contact elements forming a snap-in to co-operate with the contact element support in an operative or inserted position, an abutment surface provided at the contact element support for co-operation with the snap-in device such that shortly before reaching the end position a snap-in tongue formed by the snap-in device snaps into a snap-in opening of the contact element support so that the contact element is fixedly held in its inserted operative position.

TECHNICAL FIELD
 The invention relates to a chip or smart card reader as it is used for
 contacting so-called chip or a smart-cards. A smart-card reader is in
 substance a contacting apparatus into which a smart card is inserted such
 that the contacts on the smart card, i.e. card contacts, come in contact
 engagement with contact elements located in said contacting apparatus. The
 smart card can also be "SIM" card. SIM means subscriber identity module.
 Thus, the term SIM card relates to a card which can be used in a mobile
 telephone to identify a subscriber.
 BACKGROUND ART
 Smart card readers have been developed in many kinds of designs. Different
 methods are known to fixedly mount the contact elements of a smart card
 reader in said smart card reader and more specifically in a contact
 support of said smart card reader. Frequently, the contact elements of the
 smart card reader are fixedly mounted in the contact support of the smart
 card reader by surrounding the contact elements with the plastic material
 when injection molding the contact support.
 For instance DE-38 32 588 A1 discloses the mounting of contact elements on
 or in a contact support by detent means.
 Smart card readers are frequently built with contact elements having
 soldering contacts. These soldering contacts are adapted to be inserted
 into holes (for instance in a circuit board) and are then dipped in a
 supply of solder material for providing connection. In this context
 problems occur both with contact elements which are fixed in the contact
 support by molding (see FIG. 9) and with contact elements which are
 inserted into the contact support (see FIG. 10) and are held therein for
 instance by detent means. As far as the contact elements are concerned
 which are fixed in the contact support by molding (see FIG. 9), a good
 mechanical strength of the soldering contacts is achieved. However the
 automatic production of larger numbers of such contact supports or
 contacting apparatus is costly. If the contact elements are inserted into
 and frictionally held in the contact support as is shown in FIG. 10, then
 a load pulling on said soldering contacts could cause a destruction of the
 contact elements.
 It is an object of the present invention to provide a smart card reader,
 i.e. a smart card contacting apparatus as well as contact elements
 therefore, such that an automated insertion of the contact elements is
 easily possible.
 It is another object of the present invention to provide a contacting
 apparatus and contact support of said contacting apparatus, respectively,
 wherein after insertion of the contact elements the mechanical
 characteristics are similar to those of contact elements mounted by the
 injection molding process of the smart card reader and its contact
 support, respectively.
 It is another object of the present invention to increase the efficiency of
 the placement of the contact elements in the smart card reader.
 DISCLOSURE OF THE INVENTION
 The invention is directed to a smart card reader and a contact element
 support which preferably adapted to be used in a smart card reader. The
 contact support is preferably made of a plastic material. The contact
 support defines a card support surface and also a plurality of chambers,
 each chamber being adapted to receive each one contact element. The
 contact element has preferably the form of a contact spring and can be
 mounted in said contact element support in a snap-locked or detent
 position. Preferably, the contact elements can be inserted into said
 chambers in a direction parallel to the card support surface. Both the
 contact element and the contact element support define stop- or abutment
 surfaces which define and limit the path of insertion of each contact
 element. Said abutment surfaces are provided such that prior to reaching
 the end of the insertion path a snap- or detent tongue formed on the
 contact element snaps into a snap lock or detent opening formed by the
 contact element support. Thus, securing the contact element in said
 contact element support such that it can not become disassembled.
 In accordance with another aspect of the invention a method for
 manufacturing a smart card reader having a contact element support is
 provided. Contact elements are snapped into a snap-locked position when
 inserting said contact elements into said contact element support in a
 direction in substance parallel to the card support surface.
 In accordance with another aspect of the invention a contact element is
 provided which comprises a terminal or a contact section, a fastening
 section, a connection section, a seat section, a contact cusp or contact
 bump tip section as well as a snap tongue formed in the region of the
 fastening section. The fastening section further forms abutment or stop
 surfaces that are suitable for stopping or abutting against corresponding
 counter-stop or counter abutment surfaces. Preferably, the snap tongue is
 stamped out from the fastening section and is bent out of the plane formed
 by the fastening section, in particular in a direction opposite to the
 direction in which the connection section is bent relative to the plane
 formed by the fastening section.

BEST MODE FOR CARRYING OUT THE INVENTION
 Referring to the drawings and more specifically to FIG. 1 a smart card
 reader 10 is shown as comprising a contact support 11 which has generally
 the form of a frame in the embodiment shown.
 The upper surface 12 of the contact support 11 forms a card support surface
 13 which bordered or limited by side guide edges 14 and abutment edges 15
 for a smart card 9. In FIG. 1 the smart card 9 is shown to be partially
 inserted with the direction of insertion being referred to by the arrow C.
 Generally, a cover not shown in FIG. 1 is mounted on the contact support 11
 and covers the card support surface 13. The cover forms together with the
 card support surface 13 a card receiving space or slot. The cover serves
 as a counter support for the card 9, so that the card 9 located in its
 fully inserted reading position is held in contact engagement, i.e. its
 card contacts contact the contact elements 21.
 The contact elements 21 are formed in large numbers in the form of a metal
 strip which comprises of a plurality of contact elements. After
 manufacture of the contact elements 21 the individual contact elements 21
 are still connected by means of a pilot strip 18. Said pilot strip 18 is
 preferably present when mounting a certain number of contact elements 21
 and it is removed only after the contact elements 21 are properly mounted
 in the contact support 11.
 In FIG. 1 two contact element regions 16 and 17 are disclosed. The contact
 elements which can preferably be in the form of contact springs 21 are of
 an elongate shape and form two groups of each four contact elements 21.
 The contact elements 21 of the group forming the contact element region 16
 extend from the left (FIG. 1) lateral side of the contact support 11
 inwardly. The other group of four contact elements forming the second
 contact element region 17 extend inwardly from the right hand lateral side
 of the contact support 11.
 FIG. 2 discloses an enlarged detail of FIG. 1 where the pilot strip 18 has
 already been removed and terminate sections 22 (see also FIG. 5) of the
 contact elements 21 have already been bent by 90.degree.. In the
 representations of FIGS. 1 and 2 as well as FIGS. 3 and 4 the contact
 elements 21 are already inserted into their detent or snap-locked position
 and terminal or contact sections 22 project away from the bottom surface
 19 (see FIG. 3) of the contact support 11. These terminal sections 22 may
 extend for instance into contact holes of a printed circuit board with
 which the smart card reader 10 is to be used. FIG. 2 shows the card
 support surface 13 of the contact support (also called contact frame) 11.
 A plurality of parallel openings or slots 20 are formed in the card
 support surface 13 and in the contact support 11 adapted to receive each
 of said contact elements 21.
 FIG. 3 in particular also FIGS. 2, 5 and 6 disclose that each contact
 element 21 comprises besides the terminal section 22 a wide fastening
 section 23, a connection section 24 as well a seat section 25. Between
 connection section 24 and seat section 25 in a cusp section 27. A snap
 tongue or detent tongue 26 is formed in the area of the fastening section
 23. The snap tongue 26 is preferably stamped out of the widened fastening
 section 23 as is shown in FIG. 6. The tongue 26 forms an abutment surface
 260 (FIG. 5) at an end opposite to the direction of insertion A (see FIG.
 3). The snap-in tongue 26 is bent out of the plane defined by the
 fastening section 23 as is shown in FIG. 5. The snap-in tongue 26 acts
 like a spring arm.
 The connection section 24 is slightly bent upwardly with respect to the
 fastening section 23 (see FIG. 5) which extends substantially parallel to
 the card support surface 13. Thus, an angle .alpha.&lt;180.degree. (FIG. 5)
 is formed between the fastening section 23 and the connection section 24.
 Depending on how the angle a is chosen the contact element 21 is biased
 against an abutment surface 51 of a rib 50 of the contact element support
 11. The contact element 21 is preferably designed as a contact spring. The
 biasing force with which the seat section 25 is biased against the
 abutment surface 51 can be larger or smaller. The termination or terminal
 section 22 comprises an angled termination pin 221 (FIGS. 3, 4 and 5).
 As can be seen in FIG. 2 the contact element 21 has in the area of its
 fastening section 23 a wider shape compared with the terminal section 22
 and also compared with the connection section 24. Because of the greater
 width of the fastening section 23 abutment surfaces 28 and 29 are formed
 at the transition from the fastening section 23 to the connecting section
 24. These abutment surfaces 28, 29 are preferably provided opposite to
 each other at both sides of the transition from the fastening section 23
 to the connection section 24. Moreover, the connection section 24
 preferably tapers starting from said abutment surface 28, 29 towards the
 cusp section 27. Due to this design the contact element 21 has a
 homogeneous distribution of the tension occurring within the contact
 element 21 with the result that the force exerted by the contact element
 21 on a contact, for instance a card contact of an inserted smart card 9,
 is guaranteed to last for a long period of operation.
 Referring now in particular to FIGS. 2 through 4 the design of the contact
 support 11 will be discussed. The contact support 11 which has the form of
 a frame comprises as is shown in FIG. 2 a plurality of contact element
 chambers or slots 30 one of which is shown in FIG. 3 in a sectional view.
 Contact elements 21 are inserted into said chambers 30 in a direction
 parallel to the card support surface 13 in the direction of the arrow A in
 FIG. 3. After insertion of the contact elements 22 into said chambers 30
 they are locked in said inserted position by detent means, i.e., the snap
 tongue 26.
 FIG. 4 is a view in the direction of the arrow A in FIG. 3 onto four such
 chambers 30.
 In accordance with FIGS. 2 and 3 each chamber 30 comprises a termination
 area 31, a fastening area 32, an opening area 33 comprising an opening 20,
 and an abutment area 34. In the fastening area 32 (se e FIG. 3) the
 contact element support 11 comprises two rib portion 40, 41 which define
 an opening 42. The opening 42 forms an abutment member or abutment surface
 43 behind which the snap-in tongue can snap-in as shown in FIG. 3. When
 the snap-in tongue is in its snap-in or snap-locked position the abutment
 surface 260 (FIG. 5) of the snap-in tongue 26 is in engagement with the
 abutment surface 43. This snap-in engagement occurs when the abutment
 surfaces 28, 29 (FIG. 6) of the mounting or fastening section 23 abut
 against respective abutment surfaces 44 (FIG. 2) of the contact support
 11. Said abutment surfaces 44 are formed preferably by the rib or rod
 portion 41 of the contact element support 11; see FIG. 8.
 FIGS. 4 and 7 show the contact element support 11 seen from the direction
 of arrow A in FIG. 3. It is noted that the contact element support 11
 forms an insert incline 130 which simplifies the insertion of the contact
 elements 21 in the direction of A into the chamber 30. FIGS. 4 and 7
 disclose in particular that widening sections 60 of the fastening section
 23 extend into slots 61, 62 which are formed on both sides of the chamber
 and thus form a guide means for the contact element 21 when it is
 inserted. Also support of the contact element 21 is provided thereby after
 the contact element 21 is in its snap-in position. Moreover, this design
 avoids a rotation of the contact elements 21 beyond an admissible range.
 In FIG. 4 reference numeral 63 refers to one of the walls of the chamber
 30.
 FIG. 7 discloses the opening 42 together with the snap-in tongue 26 which
 is in its snap-in position in said opening 42. Each of said widening
 sections 60 comprises (see FIG. 8) guide edges 602, 807 which extend
 parallel to each other. Said guide edges 602, 807 together with the side
 walls 161, 162 (FIG. 8) of the slots 61, 62 assist in holding the contact
 elements 21 in the inserted position, also called operative position.
 INDUSTRIAL APPLICABILITY
 For manufacturing a smart card reader, i.e. a smart card contacting
 apparatus 10 the following steps are taken. Contact elements, preferably
 contact springs 21 are provided and inserted into said chambers 30 in a
 directions parallel to the card abutment surface 30. During insertion the
 smart card 9 is guided until it reaches its inserted or reading position
 where the card contacts are in contact engagement with the cusps 27 of the
 contact elements 21. The contact elements 21 are locked in said inserted
 position.
 For this purpose the contact element support 11 is provided with first
 locking means, i.e. abutment 43 and the contact elements 21 are provided
 second locking means, i.e. tongue 26. Said first and second locking means
 come into a locking engagement when the contact elements reach their end
 position.
 Due to the fact, that the contact elements 21 are pushed into said contact
 support 12 i.e. the chambers 13 thereof from the lateral side(s) of said
 contact element support 12, the contact elements 21 are securely fastened
 within said contact element support 12 even if the termination section 22
 of the contact element 21 is bent downwardly preferably by 90.degree. with
 respect to the fastening section 23.