WO1998019267A1

WO1998019267A1 - Card reader

Info

Publication number: WO1998019267A1
Application number: PCT/US1997/019692
Authority: WO
Inventors: John W. Kaufman; John E. Knaub; Adam D. Cunningham
Original assignee: The Whitaker Corporation
Priority date: 1996-10-31
Filing date: 1997-10-29
Publication date: 1998-05-07
Also published as: JP2001503544A; AU5241598A; US5750973A

Abstract

A card reader (20) includes a housing (22), a plurality of resilient connector elements (70) disposed along the bottom wall (28) of the housing (22) and adapted to establish electrical connection between contact pads (104) of a circuit board (102) and contact pads (96) of a card (90) inserted into a card-receiving slot (40) of the reader (20), a horizontal plate (42) slidably mounted within the housing (22), and an actuator (54) for moving the plate (42). The horizontal plate (42) is proximate the top surface of the housing (22) and is movable upon actuation toward a card (90) inserted into the card receiving slot (40) beneath the plate (42) to exert pressure on and moving the card (90) toward the bottom wall (28) to effect electrical engagement between the contact pads (96) of the card (90) and the resilient connector elements (70) that, in turn, engage the contact pads (104) of the board (102).

Description

CARD READER

This invention is directed to card readers and more particularly to a card reader for cards having contacts on a surface thereof .

Electronic memory cards of the type having a plurality of contacts on one face thereof are widely used in electronic equipment, such as computers and the like. In some memory card readers, the card is inserted into the card reader such that the front edge of the card engages the curved portions of contacts as the card is inserted into the reader. This causes elastic deformation of the contacts and results in prolonged rubbing of the curved convex areas of the contacts during the time the card is being fully inserted into and removed from the housing. Repeated insertions and removals of cards into and out of the card reader causes wear to the contact surfaces, thus decreasing the quality of the electrical connection. It is desirable, therefore, to have a card reader wherein the card may essentially be fully inserted before the contacts in the card reader engage the conductive pads on the surface of the card.

One way to accomplish this result is to use a lever or other means to move the contacts into engagement with the card after the card has been fully inserted. With the increased use of more closely spaced contact pads on the card and the accompanying miniaturization of both the card reader and the contacts therein, it is more desirable to have a card reader in which pressure can be applied to a fully inserted card to move the card into engagement with the contacts rather than move the contacts into engagement with the card. It is desirable furthermore, to have a card reader that has a low vertical height, requires a minimum amount of space on a circuit board and has a minimum number of parts.

The present invention is directed to a card reader that overcomes deficiencies in the prior art. The card reader includes a dielectric housing, a plurality of resilient connector elements disposed along the bottom wall of the housing and adapted to establish electrical connection between the contact pads of circuit board. The housing defines a camming surface with the card receiving opening at least adjacent a top wall of the housing. A horizontal plate is slideably mounted within the housing proximate the top surface and is movable between first and second positions therein upon actuation. The plate includes a cooperating camming surface adjacent and engageable with the camming surface of the housing. The plate is adapted to be moved from a first position adjacent the top wall to a second position lower than the first position upon actuation thereof thereby moving the plate toward a card inserted into the card receiving opening beneath the plate. The plate exerts pressure on the top the card and moves the card toward the bottom wall to assure that the contact pads on the card are in electrical engagement with associated ones of the resilient contact elements, which in turn, electrically engage the contacts pads on a circuit board. The card reader further includes a actuator section exposed at least for actuation from outside of the housing for moving the plate between the first and second positions.

In one embodiment, the top wall of the housing includes at least one recess extending into an inside surface between the side walls and at a selected location therealong. The plate concomitantly includes at least one raised portion extending between its sides and dimensioned to be received in a respective recess of the top wall when the plate is in the first position. Preferably the top wall has a plurality of recesses spaced therealong and the plate has a corresponding plurality of raised portions, each dimensioned to be received in a respective recess.

In one embodiment the bottom wall of the reader has a plurality of slots extending therethrough parallel to the side walls and dimensioned to receive elongate resilient connector elements.

In another embodiment of the invention, individual resilient contact members are disposed in contact receiving apertures extending through the bottom wall.

The card reader may further include a shell member within the card receiving slot beneath the horizontal plate, the shell member being dimensioned to surround the top and side edges of a card inserted into the slot. The shell member is engaged by the plate when the plate is moved from the first to the second position. The shell and the card thus are simultaneously urged toward the bottom wall of the card reader such that contact pads on the card can engage the resilient connector element that, in turn, engages pads on a circuit board.

It is an object of the present invention to provide a card reader that minimizes wear on contact surfaces of a card reader.

It is a further object of the invention to provide a card reader having a low insertion force for the care.

Additionally it is an object of the invention to provide a card reader that may be included in a Type III PCMCIA card assembly to provide access to notebook computers and the like having the capability to use PCMCIA cards.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which like elements in different figures thereof are identified by the same reference numerals. FIGURE 1 is an isometric exploded view of a card reader made in accordance with the present invention.

FIGURE 2 is an isometric view of the card reader of Figure 1.

FIGURE 3 is a longitudinal sectional view of the card reader of Figure 1 having a card in the slot with the plate in its first position.

FIGURE 4 is a cross- sectional view of the card reader taken along line 4-4 of Figure 2 showing a card in the slot prior to moving the plate to its second position.

FIGURE 5 is a longitudinal sectional view similar to that of Figure 3 wherein the plate has been to its second position and the contacts are engaged between the card and circuit board.

FIGURE 6 is view similar to that of Figure 4 after the plate has been moved to the second position and the card is electrically engaged to contacts on the circuit board.

FIGURE 7 is an isometric view of the plate prior to overmolding of the dielectric material.

FIGURE 8 is an assembled view of the alternative embodiment of the card reader having one card receiving slot and a card disposed therein.

FIGURE 9 is a further alternative view of the card reader having an alternative embodiment of the resilient contact elements.

FIGURE 10 is a sectional view of the connector of Figure 9.

For purposes of illustrating the invention, the card reader 20 is being shown with two card reader slots 40, each dimensioned to receive a card having a plurality of contact elements on the major surface thereof. It is to be understood that the invention is also suitable for use with card reader having only a single slot 140, such as shown in Figure 8.

Referring now to Figures 1 through 7, card reader 20 includes a dielectric housing 22, a horizontal plate 42 and a plurality of resilient contact elements 70.

The dielectric housing includes a top wall 24, a bottom wall 28, opposed side walls 32, front face 36, a rear wall 38, and intermediate wall 33, together defining two card receiving slots 40. The inside surface 25 of top wall 24 includes a plurality of recesses 26 extending between side walls thereof at selected locations therealong. The inside surface 25 defines a camming surface that cooperates with the plate 42 as more fully explained below. In one embodiment, top wall 24 further includes a pattern of apertures 23 extending therethrough. Figure 1 shows the structure of one of the card- receiving slots 40 in conjunction with a card 90. Preferably housing 22 is molded from a high strength plastic such as, for example, a polycarbonate or the like. One suitable material is LEXAN available from General Electric Company, Pittsfield, Massachusetts . In a first embodiment of the invention, the bottom wall 28 includes a plurality of slots 30 dimensioned to receive elongate resilient contact elements 70. Suitable contact elements include, for example, AMPLIFLEX sold by AMP Incorporated of Harrisburg, Pennsylvania. Each AMPLIFLEX connector element 70 includes a thin flexible film member 72 having a plurality of lines of conductive circuitry 74. The film 72, in turn, is wrapped around a resilient core 76 and includes a tab 77 that is secured to the bottom of bottom wall 28 of the housing as best seen in Figures 4 and 6.

Plate 42 includes a top surface 44, a bottom surface 46, and a plurality of apertures 48 extending therebetween and a plurality of protrusions 50 extending upwardly therefrom as best seen in Figure 7. Plate 42 further includes a layer of dielectric material 60 molded over the surface of plate 42 and including a plurality of spaced raised portions 62 extending between the sides of the plate and essentially parallel to the forward and rearward ends 52, 56 respectively. Each raised portion 62 has tapered surfaces at the leading and trailing edges 63, 65 thereof and defines a camming surface 64 on the top thereof. The dielectric material 60 further forms an actuator 54 along arm 53 and rearwardly protruding compliant legs 58 having stop surfaces 59 thereon. Plate 42 preferably is stamped from stainless steel. Suitable dielectric materials include liquid crystal polymers or the like, such as E130 available from Hoechst-Celanese, Summit, New Jersey.

Upon inserting plate 42 into the card receiving slot 40, the raised portions 62 on the upper surface of the plate are received within respective corresponding recesses 26 of the top wall as best seen in Figures 3 and 4. The plate 42 is in its first position when the raised portions are in the respective recesses. As can be seen from Figure 2, the protruding compliant legs 58 extend through openings 27 at the rear of the housing 22 when the plate 42 is in its first position. The actuator 54 extends outwardly from the housing 22 along the front face 24 thereof to enable manual gripping of the actuator 54 to move the plate 42 relativity toward and away from the housing 22. Figures 3 through 6 further show the card reader 20 mounted to the circuit board 102. Bottom wall 28 further includes board locating posts 29 which are received in corresponding apertures 106 of circuit board 102. In Figures 5 and 6, the contact pads 104 on the circuit board are in electrical engagement with the corresponding contact pads 96 on the card 90.

In one embodiment, card reader 20 further includes a shell member 78 having a top surface 80, side walls 82 and outwardly extending wings 86 along the side walls 82 thereof. The leading edges 84 of the side walls 82 are curved inwardly. Shell member 78 includes apertures 83 extending through top surface 80. Shell member 78 preferably is stamped and formed from stainless steel or the like. Upon placing the shell member 78 within the card receiving slot 40, wings 86 along the side walls 82 are received in corresponding guide surfaces 34 of the housing side walls 32 and intermediate wall 33, as best seen in Figures 4 and 6. When the shell member 78 and plate 42 are in the first position, a card 90 having a top surface 92 and a lower surface 94 having a plurality of contact pads 96 thereon can be inserted into the card reader 20. The plate 42 and shell member 78 provide sufficient clearance for the card 90 to be freely received in card receiving slot 40 without engaging the resilient contacts elements 70 extending along the bottom wall 28 of the card reader 20. Upon full insertion of the card 90, the actuator 54 may be gripped by hand and pulled forwardly such that the camming surfaces 64 are moved out of the recesses 26 and into engagement with surface 25 of the top wall thus moving plate 42 to a lower or second position. The plate 42 is thus moved toward the shell member 78 and the card 90 therebeneath. The plate 42 and shell member 78 exert pressure on the top surface 92 of the card 90 thus moving the card 90 toward the bottom wall 28 to assure that the card contact pads 94 on the bottom surface thereof are brought into electrical engagement with the associated circuitry 74 of the resilient contact elements 70 that, in turn, are electrically engaged with contact pads 104 on the circuit board 102. The second position of plate 42 and shell member 78 are best seen by referring to Figures 5 and 6. As also can be seen from Figure 5, upon moving plate 42 to its second position, the resilient legs 58 are moved into the housing 22 until the stop surfaces 59 engage the rear wall 38 of the housing. As can be seen in Figures 4 and 6, the wings 86 of the shell member 78 ride vertically along the vertical guide surfaces 34 as the plate 42 is moved between its first and second positions . In one embodiment, as shown in Figure 1, top housing wall 24, plate 42, and shell member 78 include a pattern of apertures 23, 48, and 83, respectively, which permit testing for electrical continuity in the following manner. A special test card is inserted into the fully assembled card reader 20 and plate 42 and shell member 78 are then moved to their second position, thereby aligning the apertures 23, 48 and 83. A probe can then be inserted through each of the aligned apertures to test for electrical continuity between the contact members of the test card, the resilient contact elements and the circuit board pads prior to further assembly of a Type III PCMCIA card or other electrical device that includes reader 20.

Figure 8 illustrates an alternative embodiment 120 of the card reader which a includes a single card receiving slot 140 and plate 142 and having a card 190 disposed therein. Figures 9 and 10 illustrate embodiment 220 of a card reader in which the resilient contact elements 270 are individual contact members disposed in an array of apertures 230 that extend through the bottom wall 228 of housing 222. Each contact 270 includes a curved resilient portion 274 and a board engageable portion 276. Contacts 270 may be secured in the housing by retention barbs or other retention means as known in the art .

The present invention provides a cost effective connector that allows a card having contacts on the surface thereof to be inserted into a card reader without engaging the contacts of the card reader thereby minimizing wear on the contacts surfaces. The card is then brought into engagement with the contacts upon moving a actuator to increase pressure on the card thus enabling contacts of the card to be brought into electrical engagement with corresponding contacts 104 on circuit board 102. The card reader of the present invention may be used as an independent card reader or may be included in another electrical device such as a

Type III PCMCIA card frame. The card reader adapter for the PCMCIA card provides access to existing computers having the capability to access PCMCIA cards.

Claims

WE CLAIM :

1. A card reader (20) includes a housing (22) having at least one card- receiving slot (40) extending therein and a plurality of resilient connector elements (70) disposed along a bottom housing wall (28) and adapted to establish electrical connection between contact pads (104) of a circuit board and contact pads (96) of a card (90) inserted into the at least one card- receiving slot (40) ; the reader (20) being characterized in that: the housing (22) defines a camming surface (25) with the card receiving slot (40) at least adjacent a top wall (24) thereof; a horizontal plate (42) is slidably mounted within the housing (22) proximate a top surface (25) thereof and movable between first and second positions therein upon actuation, the plate (42) including a cooperating camming surface (64) adjacent and engageable with the housing camming surface (25) whereby the plate (42) is adapted to be moved from a first position adjacent the top wall (25) to the second position lower than the first position upon actuation thereof moving the plate (42) at least toward a card (90) inserted into the card receiving slot (40) beneath the plate (42) to exert pressure on a top (92) of the card (90) and moving the card (90) toward the bottom wall (28) to assure contact pads (96) thereof adjacent the bottom wall (28) are brought into electrical engagement with associated ones of the resilient connector elements (70) that, in turn, are electrically engaged with contact pads (104) on the board (102) ; and an actuator section (54) at least exposed for actuation from outside the housing (22) for moving the plate (42) between the first and second positions.

2. The card reader of claim 1 wherein the bottom wall (28) has a plurality of elongate slots (30) extending therethrough and parallel to side housing walls (32) and dimensioned to receive the resilient connector elements (70).

3. The card reader of claim 1 wherein the resilient connector elements (70) are elongate elastomeric members.

4. The card reader (20) of claim 1 wherein the actuator section (54) extends outwardly from the housing (22) to enable manual gripping thereof to move the plate (42) relatively toward and away from the housing (22).

5. The card reader of claim 1 wherein the top wall (24) includes at least one recess (26) extending into an inside surface (25) thereof between side walls (32) thereof and at a selected location therealong and the plate (42) includes at least one raised portion (62) extending between sides thereof and dimensioned to be received in a respective the at least one recess (26) when the plate (42) is in the first position.

6. The card reader of claim 1 wherein the top wall (24) includes a plurality of recesses (26) spaced along the wall (24) between a front face (36) and rear wall (38) of the housing (22) and the plate (44) includes a plurality of raised portions (62), each dimensioned to be received in a respective recess (26) when the plate (42) is in the first position.

7. The card reader of claim 1 further including a shell member (78) within the card- receiving slot (40) beneath the plate (42) and surrounding the top and side edges of a card (90) inserted into the slot (40) , and engaged by the plate (42), whereby the shell member (78) and the card therein are simultaneously urged toward the bottom wall (28) .

8. The card reader (20) of claim 7 wherein wings (86) of the shell member ride vertically along vertical guide surfaces spaced inwardly from the front wall.

9. The card reader of claim 1 wherein the bottom wall (28) has a plurality of apertures (23) extending therethrough and dimensioned to receive the resilient connector elements (170) .

10. The card reader of claim 1 wherein the housing ^• (22) further includes at least one intermediate (33) wall extending between the top and bottom walls (24,28) and parallel to the side walls (32), the at least one intermediate wall (33) dividing the housing (22) into at least two card receiving slots (40) .