Modular card read/write apparatus
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to modular magnetic card readers/writers, to be installed in associated mechanisms, and pertains, more particularly to a modular reader/writer assembly. The modular assembly is capable of reading cards of various sizes and configurations without modifications, and readily adapts to various path length constraints of associated mechanisms. 
     2. Description of the Prior Art 
     Magnetic card read/write assemblies are traditionally configured to accept one size card only. Applications requiring acceptance of multiple card sizes would require multiple readers. Further, cards having magnetic data encoded on different tracks are generally not processed by a single read/write assembly. Finally, applications requiring a specific card path length in order to allow ejection of the card into the associated mechanism require custom design and construction of a read/write assembly. 
     An object of this invention is to provide a magnetic card read/write apparatus in which magnetic cards of different sizes can be read or written on without modification of the apparatus. 
     It is a further object of this invention to provide a magnetic card read/write apparatus capable of reading magnetic data encoded on different card tracks without modification of the apparatus. 
     It is a further object of this invention to provide a modular read/write assembly to provide customized path lengths with the use of basic components. 
     SUMMARY OF THE INVENTION 
     To accomplish the foregoing and other objects of this invention there is provided a modular read/write apparatus. 
     Modular read/write assemblies are interlocked linearly by snap-lock projections to form the desired card path length, avoiding costly custom design. The card path length is the distance necessary to allow the apparatus to eject the card directly into the associated mechanism if desired. In addition, multiple read/write assemblies may also be constructed for the purpose of use of the multiple magnetic heads. Each head would be positioned to read data located along a particular track of the card, allowing one apparatus to read cards with magnetic data encoded at different locations on the card. 
     The module assembly includes a spring device to properly align a card for reading regardless of its size. This allows the use of various card sizes, typically CR-50 and CR-80 without modification of the apparatus. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is an exploded view of the read/write apparatus having a two read/write module construction. 
     FIG. 2 is an exploded view of a single read/write module. 
     FIG. 3 is a perspective view of the molded module bottom assembly. 
     FIG. 4 is a perspective view of the molded module top assembly. 
     FIG. 5 is a front view of two assembled read/write modules. 
     FIG. 6 is a top view of two assembled read/write modules. 
     FIG. 7 is a side view of two assembled read/write modules. 
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawings, there is shown a preferred embodiment for the read/write apparatus. 
     The magnetic card read/write apparatus 10, shown in FIG. 1 is encased by enclosure 26 assembled from top 28, back 32, base 36 and side 30, 30&#39; sections. Back section 32 includes a slot 34 for ejection of the card. The front adaptor 12 houses an LCD display 16 under lens 14. The display is illuminated by switch 18 which provides momentary backlight. Adaptor 12 further supports nose section 20 through which a magnetic card can be introduced into the apparatus 10. A control circuitry board 22 is located above the reader module 38, which is described in detail below. The read/write circuity 24 is located below the reader module 38. A standard bar code reader 21 is located at the card receiving end of the read/write module 38. The electronic circuitry utilized by the apparatus being conventional and well-known in the art it will not be discussed in detail. 
     The reader module 38 shown in FIG. 2 is constructed from a molded bottom assembly 40 and a molded top assembly 42. 
     The bottom assembly 40 shown in FIG. 3 includes a base portion 44 and side support portions 48, 50. The base portion 40 includes integral raised card track portions 46 to minimize friction and a depression 52 housing a felt dust collector 54. 
     Each side portion 48, 50 includes a u-shaped projection 56 extending outwardly from the side 48,50 at one corner, and a u accepting projection 58, including tapered portion 60, indentation 62, and bottom 64 portion, extending outward from the opposite corner to provide for modular interlock. Side 50 includes tapered inverted L-shaped projections 74, 74&#39; extending upwardly from bottom assembly 40. Side 48 includes two rectangular projections extending outwardly from bottom assembly 40 having tapered upper inner corners. 
     As seen in FIG. 2 aperture 70 provides access to the card for a driven roller 78. Drive roller 78 is mounted between drive bearings 88, 88&#39; on drive shaft 90 which is supported by bottom assembly side 50 through aperture 84. Drive gear 92, located on the exterior of side 50 turns the drive shaft 90 and roller 78 in response to turning of gears 86, 86&#39; on gear axles 94, 94&#39; initiated by the movement of motor gear 82 by motor 80. Motor 80 is supported by side 50 through aperture 68 and is mounted to side 50 through apertures 66, 66&#39;. Aperture 72 accommodates the magnetic head 100, which is supported by head holder 96 and holder retainers 98, 98&#39; mounted on bottom assembly base 44. Spring 102 having leading edge portion 104 is supported on bottom assembly 44 by supports 106, 106&#39;. 
     The top assembly 42 shown in FIG. 4 includes integral raised card track portions 111 to minimize friction, two elongated tapered hook projections 110, 110&#39; at side 43 and extending downwardly from assembly 42, and two tapered hook projections, 108, 108&#39; at side 43&#39; extending outwardly from top assembly 42. Sensor slots 113, 113&#39; provide access for use of a convention electronic sensing device to detect the presence of a card in the read/write module 38. As seen in FIG. 2, aperture 112 provides the roller idler 124 access to the card, and aperture 114 provides access to the anvil idler roller 120. The roller idler 124 and the anvil idler roller 118 move about axles 126 and 120 respectively, both axles being supported on assembly 42 by depressed notches 116, 116&#39;, and are held in place by idler spring 128 and idler anvil spring 122 respectively. 
     When assembled, top assembly 42 and bottom assembly 40 are aligned so that bottom assembly side 40 is in contact with top side 43. The assemblies are snapped into place so that bottom projections 74, 74&#39; are hooked together with top projections 108, 108&#39;, and top projections 110, 110&#39; are hooked under bottom projections 76, 76&#39;. When assembled, a card path is provided between the top and bottom assemblies. 
     To increase the path length of the card, two or more reader modules can be linearly assembled. Two modules are connected by holding the modules at a slight angle to each other so that each u-shaped projection 56 is resting above and against the tapered portion 60 of the u-accepting projection 58. The modules are then twisted into the same plane so that the u-shaped projections 56 expand over the tapered portions 60 of the acceptor projections 58 and lock into place against the indented portion 62 of the acceptor 58. 
     1. Operation of a One Module Assembly 
     The card to be read is introduced through the nose section 20. The leading edge 104 of card spring 102 urges the card into alignment by applying pressure against one edge of the card so that the opposite edge of the card is directed against one side of the read/write module 38. This allows various card sizes, typically CR-80 and CR-50 to be used without additional modifications by insuring that each card is moving along the same track. Once the card reaches the driven roller 78 the movement of the card is controlled by the read/write module 38. Roller 78 moves the card into position for the magnetic head 100 to read the data encoded on the card. The data is then transferred to the associated mechanism by the control circuitry 22. Upon receipt of directions from the associated mechanism, the control circuitry 22 may direct the magnetic head 100 to write on the card, after which motor 80 may be instructed to cause the roller 78 to either move the card in a forward direction thereby ejecting the card into the associated mechanism through slot 34 or reversing roller 78 direction and ejecting the card through the nose 20, returning the card to the user. 
     2. Operation of Two or More Modules 
     The card is introduced through nose section 20, aligned by spring 102 and moved into position for reading by magnetic head 100 as described for the operation of a one module assembly. After data transfer by control circuitry 22 several options exist. If data transfer is complete, the card can be ejected through the nose section 20 or ejected through the remaining module into the associated mechanism through slot 34. If the data read by the first module is insufficient, roller 78 can move the card into the second module for reading by a second magnetic head 100&#39;, typically located at a different position than magnetic head 100. At the completion of data transfer, the card can be ejected through the nose section 20 by travelling through the first module, or can be ejected directly into the associated mechanism by the second module 38&#39; through slot 34. 
     The number of modules to be connected is determined by one or both of the following conditions. The path length can be determined so as to allow the card to be ejected into the associated mechanism. The number of modules having read/write capabilities can be determined by the number of different configurations of magnetic cards necessary for the apparatus to be able to read or write on for the particular application. 
     From the foregoing description, those skilled in the art will appreciate that all the objects of the present invention are realized. A modular card read/write apparatus capable of accepting cards of different sizes without modification to the apparatus is provided. Further, the modular assembly provides a read/write apparatus capable of reading or writing on cards having magnetic data encoded on different card tracks, as well as provided customized card path length. 
     While a specific embodiment has been shown and described, many variations are possible. The read/write head and the dimensions of the modular components may be changed to allow use of a different read/write mechanism, including bar code, smart card and optical card read/write systems. 
     Having described the invention in detail, those skilled in the art will appreciate that modifications may be made of the invention without departing from its spirit. Therefore, it is not intended that the scope of the invention be limited to the specific embodiment illustrated and described. Rather, it is intended that the scope of this invention be determined by the appended claims and their equivalents.