Ribbon cassette with bi-color capability
BACKGROUND OF THE INVENTION 
     This invention relates to a cassette for storing an inked ribbon in which the cassette may be operated in a first mode when a single &#34;color&#34; ribbon is used, and a second mode when a &#34;bi-color&#34; ribbon is used so as to obtain, for example, bi-color printing capability. 
     Some of the problems with prior art ribbon shifting mechanisms which are used to obtain bi-color printing capability are that they are generally complex, expensive to manufacture, and have a large mass which must be shifted. Some prior art ribbon shifting mechanisms are shown in U.S. Pat. Nos. 3,897,867, 3,904,016 and 3,904,017. 
     The present invention obviates the problems mentioned in the previous paragraph in addition to realizing the usual benefits derived from ribbon cassettes, ie. low cost, ease and cleanliness of changing ribbons, etc. The cassette of this invention may be used with various business machines like accounting machines, printers, etc. 
     SUMMARY OF THE INVENTION 
     This invention relates to a ribbon cassette having a body portion, means for supporting a ribbon in an operating plane, and first and second means connecting the supporting means with the body portion. The second means is removable to enable the cassette to be operated in first and second modes. When operated in the first mode, the supporting means is fixed relative to the body portion for use with single &#34;color&#34; inked ribbons. Upon the removal of the second means, the cassette is enabled to permit the supporting means to shift or pivot relative to the body portion on the first means to obtain bi-color printing capability. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a general, exploded view, in perspective, of a ribbon cassette made according to the principles of this invention, showing a body portion, ribbon supporting means for supporting a ribbon in an operating plane, and a cover portion for the cassette; 
     FIG. 2 is a plan view of the body portion of the cassette, and first and second means connecting the ribbon supporting means to the body portion; and 
     FIG. 3 is a cross-sectional view, taken along the line 3--3 of FIG. 2, to show additional details of the first and second connecting means, and the means for connecting the cassette to a utilization device like a printer. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1 is a general, exploded view, in perspective, of a ribbon cassette designated generally as 10 and made according to the principles of this invention. The cassette 10 includes a body portion designated generally as 12, a ribbon supporting means 14, and a cover portion 16. 
     The body portion 12 (FIG. 1) includes a chamber 18 for storing a ribbon 20, which in the embodiment shown, is an endless ribbon which contains random convolutions or folds when stuffed into the chamber 18. The ribbon 20 exits from the chamber 18 around a post 22, is guided around the ribbon supporting means 14 (as will be described in detail hereinafter) and is returned to the chamber 18 via a feed means including a conventional drive wheel 24 and an idler wheel 26 which is resiliently biased into engagement with the drive wheel 24 by a cantilever type resilient lever spring 28. The drive wheel 24 is rotatably supported in arcuately shaped supports 30, and similarly, idler wheel 26 is rotatably supported in arcuately shaped supports 32 located on the free end of lever spring 28. The drive wheel 24 has a splined driving hole 34 therein which is aligned with a hole 36 in the body portion 12 to enable the drive wheel 24 to be driven by an external driving shaft (not shown) which is associated with the machine with which the cassette 10 is used. When the drive wheel 24 is rotated in a clockwise direction as viewed in FIG. 1, the ribbon 20 is pulled out of the chamber 18 at post 22, is pulled through the ribbon supporting means 14, and is pushed or stuffed back into the storage chamber 18. 
     The ribbon supporting means 14 (FIG. 2) is connected to the body portion 12 by a first means or hinge means including bar segments 38 and 40, and a second means which is a fracturable segment 42. The ribbon supporting means 14 has wall segments 44, 46 extending therefrom, and the bar segments 38 and 40 are integrally formed therewith as is best shown in FIG. 3. The opposite ends of the bar segments 38 and 40 are integrally formed with walls 48 and 50 which are part of the body portion 12. The fracturable segment 42 is planar, having a reduced, cross-sectional area 52 (FIG. 1), where it is joined to a connecting section 54, and also having a reduced, cross-sectional area 56 where it is joined to a connecting edge 58 of a joining section 60 on the body portion 12. 
     The ribbon supporting means 14 has channels formed on opposed sides thereof to enable the ribbon 20 to be guided to an operating plane (formed by the spaced, parallel edges 62, 64) as is best seen in FIG. 1. The channels are formed by laterally displaced walls 66, 68 (FIG. 1) and similar, laterally-displaced walls 70, 72 (FIG. 2) to enable the ribbon 20 to pass therebetween as is best shown in FIG. 2. The walls 68, 72 have lip portions 74, 76 respectively, extending slightly therefrom to support the lower edge of the ribbon 20 as it is pulled around the edges 62, 64 of these walls 68, 72 by the drive and idler wheels 24, 26. The connecting section 54 has similar lip portions 78, 80 (FIG. 1) extending from opposed sides thereof to similarly retain the upper edge of ribbon 20. The path of the ribbon 20 from post 22 in FIG. 2 is such that it passes around a post 82 (in which wall 46 terminates), inside wall 70, outside of wall 72, around the edges 64 and 62 (forming the operating plane where the ribbon 20 is supported in operative or printing relationship with a utilization device like a print means 84 and platen 86 as shown in FIG. 3), outside wall 68, inside wall 66, and around a post 88 (in which wall 66 terminates) and is then routed to the drive and idler wheels 24, 26. 
     The body portion 12, ribbon supporting means 14, bar segments 38 and 40 (forming the hinge means) and the fracturable segment 42 are integrally formed from a plastic material like phenelyene oxide into a single piece construction by conventional injection moulding techniques. Phenelyene oxide is a tough plastic which is manufactured, for example, by The General Electric Company and is sold under that company&#39;s trademark &#34;Noryl&#34;; it is a tough and flexible material without being brittle. Another satisfactory plastic material which may be used is a polycarbonate plastic which is sold under the trademark &#34;Lexan&#34;. 
     The cover portion 16 (FIG. 1) is shaped to cover the body portion 12 and thereby retain the ribbon 20 in the cassette 10. In the embodiment shown, the body portion 12 has an opening 90 therein to receive the print means 84 (FIG. 3) and the cover portion 16 has an arcuately shaped section 92 formed therein for the same reason. The cover portion 16 also has holes 94 and 96 therein which are aligned with the tubular posts 98, 100, respectively, which are integrally formed with the body portion 12 to enable a &#34;U&#34;-shaped member 102 to secure the cover portion 16 to the body portion 12 and to a mounting plate 104 (FIG. 3). The &#34;U&#34;-shaped member 102 has legs 106, 108 which are received by the holes 94, 96, and by tubular posts 98, 100 (located in the body portion 12) to detachably lock the cassette 10 to the mounting plate 104 when assembled thereon. The lower ends of the tubular posts 98, 100 have sections 110, 112 which pass through matching holes 105 in the plate 104. When the &#34;U&#34;-shaped member 102 is inserted in the tubular posts 98, 100, the lower ends of the legs 106, 108 (which have trapezoidally shaped sections 107, 109 thereon) cause the sections 110, 112 (FIG. 3) associated with each of the tubular posts 98, 100 to expand and detachably lock the cassette 10 to the plate 104. 
     The cover portion 16 also has resilient means extending therefrom which means is a cantilever type leaf spring 114. The leaf spring 114 (FIG. 1) is integrally formed with the cover portion 16 and biases the ribbon supporting means 14 in a downward direction (as viewed in FIG. 1) when the fracturable segment 42 is removed. 
     The cassette 10 can be operated in first and second modes. In the first mode, the fracturable segment 42 is not removed, and therefore, the ribbon supporting means 14 remains fixed relative to the body portion 12 as shown in FIG. 3. Usually, a single colored inked ribbon is installed in the cassette 10 when the cassette 10 is to be operated in the first mode. 
     When the cassette 10 is to be operated in the second mode, a bi-colored ribbon 20 is installed in the cassette 10 and the fracturable segment 42 is removed by fracturing it. When the segment 42 is removed, the ribbon mounting means 14 is enabled to pivot on the bar segments 38, 40 between first and second positions relative to the body portion 12. The leaf spring 114 biases the ribbon supporting portion 14 in a downward direction (as viewed in FIG. 3) to bring the top half 20A or first color of the ribbon 20 into operative proximity with the print means 84 (which may be a wire matrix printer for example). When it is desired to operate the ribbon supporting means 14 in the second position to utilize the bottom half 20B or second color of the ribbon 20, the ribbon supporting means 14 is merely pushed upwardly (as viewed in FIG. 3) by an external member like a solenoid 116. When the solenoid 116 is energized, its operating plunger 118 engages a contact area 120 on the underside of the ribbon supporting means 14 to push it upwardly. In the embodiment shown, the ribbon supporting means 14 is biased downwardly below the center line 122 to the first position by an angle of about 7 degrees, and is pushed above the center line 122 to a second position by an angle of about 3 degrees by the solenoid 116. The movement of the ribbon supporting means 14 in the downward direction (as viewed in FIG. 3) is limited by the lower end of wall 46 abutting against the lower end of wall 50. The upward pivoting movement of the ribbon supporting means 14 is correspondingly limited. 
     While the cassette 10 has been described with regard to an inked ribbon 20, it is conceivable that the cassette 10 may store other ribbon like materials like magnetic tape or film whenever shifting is required to obtain the benefits of this invention. Also, while a ribbon cassette 10 of the stuffed ribbon type is selected to portray the invention, reel type cassettes or cassettes employing mobius loops may be employed by simply conventionally adjusting the storage chamber 18 of the cassette 10.