Abstract:
A mechanism for establishing the requisite drive tension in a magnetic tape cartridge, and, by means of the same mechanism effecting the ejectment of the cartridge at such time as the magnetic recording or transcribing operation is complete. In an alternative embodiment designed for use in situations where the magnetic tape cartridge is inserted and ejected in the vertical plane, an auxiliary spring is utilized to supplement the tensioning and ejectment forces otherwise operative.

Description:
BACKGROUND OF THE INVENTION 
     This is an extension of the disclosure comprising application Ser. No. 918,950 filed June 29, 1978 by Alexander Hunter entitled Tape Cartridge Receiving And Locking Mechanism. 
     In the aforementioned Hunter application there is disclosed a mechanism for receiving and locking a magnetic tape cartridge for purposes of recording or transcribing information thereon. The present invention supplements the aforementioned disclosure in that it provides means for establishing the requisite tension to both drive the magnetic tape and to eject the tape cartridge after completion of the recording or transcription of information thereon. 
     In the prior art devices, including the DGD-1 Data Cartridge Drive manufactured and distributed by the 3M Company, the means for establishing the desired tension to drive the magnetic tape is mechanically independent of the cartridge ejectment mechanism. In contrast, in a preferred embodiment of the subject invention a single mechanism is used for establishing both the requisite drive tension for the magnetic tape and for subsequently ejecting the tape cartridge. 
     SUMMARY OF THE INVENTION 
     As an extension of the basic design considerations embodied in the aforementioned Cartridge Receiving and Locking Mechanism application, an attempt has been made to simplify the cartridge handler embodying the principles of the present invention by eliminating all extraneous moveable parts and, insofar as possible, combining the functions served by each such part, thereby reducing to a minimum the total number of parts required to produce an operative unit. 
     In furtherance of this design criteria, applicant has produced a balanced system in which the forces imparted to the capstan used to drive the magnetic tape are also used to effect the ejectment of the magnetic cartridge. The manner in which the above outlined objective is effected will become more readily apparent upon reference to the following description when considered in conjunction with the detailed drawings, which drawings form a part of the specification. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 comprises a front perspective view of the tape cartridge tensioning and ejecting mechanism with a partial cut-away to show details of a capstan assembly; 
     FIG. 2 discloses in plan view, an alternative embodiment to the subject invention in which a supplemental spring is used to influence the ejection of the tape cartridge; 
     FIG. 3 shows a side view of the subject invention while 
     FIG. 3A depicts details of the supplemental spring of FIG. 2; 
     FIGS. 4A and 4B comprise side views of the subject invention with partial cut-aways to show details of the capstan assembly prior to insertion of the tape cartridge and with the cartridge moved into locked position; 
     FIG. 5 comprises a cross-sectional view taken along the lines 5--5 of FIG. 4 and depicts a biasing spring used to lock the tape cartridge in position. 
    
    
     DESCRIPTION OF THE INVENTION 
     Referring now to FIG. 1, therein is illustrated the preferred embodiment of the Tape Cartridge Tensioning and Ejecting Mechanism generally designated therein as member 10. The tensioning and ejecting mechanism comprises the three major components disclosed and claimed in the aforementioned Cartridge Receiving and Locking Mechanism patent application Ser. No. 918,950. These in turn comprise a front plate and table portion 12, a rocker arm 14 and a relatively straight biasing spring 16. The front plate portion of member 12 is shown as having an opening 20 designed to accommodate a magnetic tape cartridge 18 of conventional design. Above the opening 20 of the front plate 12 is a cut out portion 22 through which there projects a release button 24 which in turn comprises a projection of the rocker arm 14. 
     Projecting perpendicularly from the front plate portion of member 12 and comprising an integral part thereof is a table portion 12A upon which the magnetic cartridge 18 is supported as it rides into locking position. Elongated guides 30 bordering each side of the table 12A restrict relative motion of the cartridge 18 to a path parallel with that of the table 12A. The location and geometric configuration of the guides 30 are defined by the physical parameters of the cartridge 18 with respect to the other operative components of the tape cartridge tensioning and ejecting mechanism. As viewed in FIG. 2, these other components include a magnetic sensing and recording head 32, a microswitch assembly 34, a photoelectric emitter (not shown) and a tape drive motor and capstan assembly 38. 
     The releasing rocker arm 14 is pivotally mounted on the front plate and table 12 by means of projections 40 integrally moulded to member 12. The projections 40 cooperate with recesses 42 on the rocker arm 14 thus facilitating a limited rocking motion of member 14 relative to the front plate and table 12. 
     As will be noted upon further reference to FIG. 2, the rocker arm 14 has a bend occurring midway up the arms of the U shaped member, proximate to the point where the rocker arm pivots about the projections 40. On the extremities of the rocker arm extensions are located two stops 46 which are designed to cooperate with cutouts 50 located on the underside of the magnetic cartridge 18. The biasing spring 16 passes through the eye of a projection 48 attached to the bottom of the table 12A (See FIG. 5). The biasing spring 16 bridges the projecting arms of the rocker arm 14 at points 14B and 14B 1  near the periphery thereof. The effect of spring 16 is to normally tend to project the stops 46 above the surface of the table 12A such that upon insertion of a tape cartridge through the mouth located on the front portion of the table 12, the leading edge portion 18A thereof rides over the projecting stops 46 until the latter engage the recesses 50 located on the underside of the magnetic tape cartridge under the influence of the biasing spring 16, thus effectively locking the cartridge to the table 12A. For further details of the cartridge receiving and locking mechanism reference is made to the aforementioned co-pending application of the same inventor, Ser. No. 918,950. 
     Reference is now made to the embodiment of the present invention disclosed in FIG. 1. As seen therein, the tape cartridge 18 has been partially inserted through the opening of the front plate 12. In this position, the leading edge 18A of the magnetic cartridge has not yet come into contact with the operative components of the cartridge tensioning and ejecting mechanism comprising the capstan assembly 38. 
     As may be seen from FIGS. 3 and 4, the capstan assembly 38 comprises a drive wheel 49 mounted on a drive shaft 51 which also serves to carry the armature of a motor 55. The capstan assembly 38 is pivotally mounted by means of a bracket 53 operatively connected so as to pivot about point 52 under the influence of a spring 54. As may be seen from FIGS. 1 and 3, in the absence of a tape cartridge the drive wheel 49 projects into the path of a magnetic tape cartridge being inserted into the subject mechanism. Thus, as a tape cartridge is inserted through the opening 20 and is moved into locking position across the table portion 12A, it comes into contact with the drive wheel 49 of the capstan assembly 38. The pressure exerted upon the magnetic tape cartridge upon insertion must be sufficient to cause the capstan assembly 38 and its associated mounting bracket 53 to pivot about their common pivot point 52 against the restoring force of the spring 54. Thus, the insertion of the magnetic tape cartridge causes a compression force to be developed within the spring 54 which in turn holds the drive wheel 49 of the capstan assembly 38 under desired tension with respect to a driven wheel 57 of the magnetic tape cartridge 18. The driven wheel 57 comprises an integral part of the tape cartridge designed for use in conjunction with the subject system, an example of which is described in detail in U.S. Pat. No. 3,692,255. 
     As the magnetic tape cartridge approaches its locking position on the table portion 12A the projecting stops 46 on the rocker arm 14 move into engagement with the cutouts 50 (See FIG. 4B) located on the underside of the tape cartridge 18 thus restraining the tape cartridge against further motion relative to the table portion 12A and preventing the tape cartridge from automatically being ejected due to the compressive force now stored in the spring 54. At the same time as the tape cartridge reaches its locking position the surface of the magnetic tape comes into contact with a magnetic sensing and recording head 32. 
     Just before the tape cartridge reaches its locked position, the capstan assembly 38, which prior to the insertion of the tape cartridge assumed a slanted position and projected into the path of the oncoming tape cartridge, is engaged by the leading edge 18A of the tape cartridge and urged out of the path thereof. Thus, as the tape cartridge reaches its locked position the capstan assembly assumes an orientation relatively perpendicular to the plane defined by the table portion. This insures that the proper tension will be developed in the magnetic tape vis-a-vis the sensing and recording head 32. 
     It should be clear that the re-orientation of the capstan assembly 38 with respect to the table portion, is accomplished by reason of the forces being exerted to overcome the effect of the biasing spring 54. The energy which is stored in the compression of spring 54 will subsequently be utilized in ejecting the tape cartridge. Thus, upon depressing button 24, which in turn retracts the stops 46 from the indentations 50 located on the underside of the magnetic cartridge 18, the restoring force within the spring 54 is released causing the tape cartridge to be projected through the mouth 20 so as to facilitate the ready removal thereof. 
     As may be seen from FIG. 2 and 3, the alternative embodiment therein disclosed embodies a supplemental restoring device comprising a housing 56 integrally mounted with respect to the table 12A such that upon insertion into the mechanism 10 of a magnetic tape cartridge, the leading edge 13A portion of said cartridge will come into contact with a projection 58 the latter being an extension of a plunger, or piston, 60 which reciprocates within the housing 56. As the tape cartridge continues to be projected across the table 12A in the direction of the capstan assembly 38, the leading edge of the tape cartridge engages the projection 58 causing the restoring spring 62 to expand such that upon subsequent depression of the button 24 the restoring force of the spring 62, acting in concert with the restoring force of the biasing spring 54, will serve to eject the tape cartridge from the mouth 20. It should be noted that the supplemental restoring force of the alternative embodiment of the present invention disclosed in FIGS. 2 and 3 is particularly designed for vertical installations of the subject Tape Cartridge Tensioning And Ejecting Mechanism. 
     Although the specification defines a cartridge tensioning and ejecting mechanism of preferred design it will be appreciated that the invention is not limited thereto. Accordingly, any modifications, variations, or equivalent arrangement within the scope of the appended claims should be considered to be within the scope of the invention. Having thus described in detail my invention,