Abstract:
A loading mechanism for an apparatus for recording or reproducing information using an information disc, which mechanism includes guides for the disc edge. The guides include a supporting guide constructed as a support for the disc edge pressed against it and a loading guide constructed as a rotationally drivable transport wheel, which rolls the information disc into and out of the apparatus for the purpose of loading and unloading, respectively, the supporting guide and the loading guide guiding the information disc along a loading path. The loading mechanism has minimal dimensions and enables the information disc to be loaded and unloaded without the surface of the disc being touched. This is achieved by the supporting guide and the loading guide being supported so as to be movable in a loading plane.

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The invention relates to the field of mechanisms for loading and unloading disk-shaped record carriers in decks of information recording or reproducing equipment. 
     The invention relates to a loading mechanism for an apparatus for recording and/or reproducing information on/from an information disc, which mechanism includes guides for the disc edge. The guides include a supporting guide constructed as a support for the disc edge pressed against it and a loading guide constructed as a rotationally drivable transport wheel which rolls the information disc into and out of the apparatus for the purpose of loading and unloading, respectively. The supporting guide and the loading guide guide the information disc along a loading path. 
     Such a device is known from U.S. Pat. No. 5,163,040. The information disc is introduced into the apparatus through a slot. In the apparatus the information disc is guided at one side by a rigid curved and grooved guide member as a supporting guide and at the other side it is guided by a grooved rubber roller as a loading guide. The rubber roller can be driven by a motor. To introduce the information disc into the apparatus it is manually inserted into the slot of the apparatus and brought into engagement with the grooves of the supporting guide and the loading guide. Subsequently, the motor is started either by means of a manually actuated switch or by means of a detection member, which detects the information disc engaging the groove of the supporting guide and the groove of the loading guide. The rubber roller of the loading guide is motor driven during the loading process and rolls the information disc between itself and the supporting guide along a curved loading path in the apparatus. 
     However, a construction of this kind has several disadvantages. Owing to the use of the curved supporting guide, the information disc can be introduced into the apparatus only along a curved loading path, insertion along a straight path, however, being impossible. As compared with straight-line insertion of the information disc it requires a larger width of the loading mechanism and hence of the apparatus. Particularly for automotive uses this is a considerable drawback, because the room available for mounting of the apparatus is then limited. 
     The round information discs have a central positioning hole. In order to treat the disc surface with care, it is advantageous if a user touches the information disc only at the edge of the positioning hole and at the periphery of the information disc. In the known arrangement the center of the information disc must be inserted by hand up to at least the location of the center of the rubber roller of the loading guide into the position referred to below as the intermediate position, before the loading mechanism automatically takes over the insertion of the information disc. In this intermediate position the positioning hole is no longer situated outside the housing front and the user cannot hold the information disc in the desired manner at the edge of the positioning hole and at the periphery of the information disc. As a result, the user is forced to touch the information-disc surface in order to bring the information disc into the intermediate position. This results in increased wear of the information discs. The above citation is hereby incorporated in whole by reference. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide a loading mechanism of the type defined in the opening paragraph, which has minimal dimensions and which enables the information disc to be loaded and unloaded without the surface of said disc being touched. 
     According to the invention this object is achieved in that the supporting guide and the loading guide are supported so as to be movable in a loading plane. 
     The movability of the supporting guide and the loading guide allows these guides to move in accordance with the outline of the information disc and thus guide the disc edge of the information disc in a flexible manner. This enables the information disc to be loaded along substantially arbitrarily definable loading paths. Information discs not having a circular disc edge (for example having oval or other disc edges) can also be rolled into the apparatus by means of such a loading mechanism. A variety of constructions can be envisaged in order to obtain the movability of the supporting guide and the loading guide. For example, the supporting guide and the loading guide can be guided in grooves and can be urged against the disc edge in these grooves by spring force or by means of actuators. 
     The guides engage with the information disc at its edges only, whereas these guides remain clear of the signal-storage surface of the information disc. This precludes possible damage to the signal-storage surface. 
     In the intermediate position, into which the information disc is inserted by the user and from which the information disc is automatically rolled inward by the loading mechanism, the positioning hole of the information disc is situated outside the housing front. As a result of this, the user can bring the information disc by hand into the intermediate position in such a way that the hand of the user only touches said disc at the inner edge of the positioning hole of the information disc and at the periphery of the information disc. This precludes damage to the surface of the information disc by contact with the hand of the user. It is also possible to remove the information disc in the same way from the apparatus in an eject position. In the eject position the supporting guide and the loading guide also engage with the disc edge of the information disc and the information disc is held in a stable manner by the supporting guide and the loading guide, so as to prevent the information disc from inadvertendy rolling out of the apparatus. The loading mechanism can be constructed in such a manner that the information disc projects from the front of the housing over approximately 85% of its diameter. 
     A further advantageous embodiment of the invention is characterized in that the supporting guide and the loading guide are carried by pivotal arms which are supported at one end. 
     This is a particularly advantageous and low cost possibility of realizing the movability of the supporting guide and the loading guide. By arranging the guides on pivotal arms these guides can be pivoted in accordance with the outline of the information disc. 
     A further advantageous embodiment of the invention is characterized in that the supporting guide and the loading guide guide the information disc along a substantially rectilinear loading path during loading and unloading. 
     As a result of the straight-line insertion movement of the information disc the width required for the loading mechanism is essentially determined by the diameter of the information disc and the housing of the loading mechanism can be made correspondingly small. Particularly for automotive uses this is a great advantage, because the room available for mounting of the apparatus is then limited. 
     A further advantageous embodiment of the invention is characterized in that the two pivotal arms are each pretensioned towards the center of the loading plane. 
     The supporting guide and the loading guide arranged on the pivotal arms are urged against the disc edge by the pretension of the pivotal arms and can thus guide the disc edge in a flexible manner during loading and unloading of the information disc. 
     A further advantageous embodiment of the invention is characterized in that the pivotal arms are coupled to one another. 
     A further advantageous embodiment of the invention is characterized in that the two pivotal arms are coupled by means of a tension spring acting between the two pivotal arms. 
     A tension spring is a constructionally simple possibility of urging the ends of the pivotal arms towards one another. 
     A further advantageous embodiment of the invention is characterized in that the pivotal arms are coupled by a coupling rod, and at least one of the pivotal arms is retensioned towards the center of the loading plane. 
     The supporting guide and the loading guide arranged on the pivotal arms are urged against the disc edge by the pretension of at least one of the pivotal arms. The pivotal arm which is pretensioned towards a central point of the mechanism in the loading plane acts upon the non-pretensioned pivotal arm by means of the coupling rod, in such a manner that the latter is also subject to a force towards the center of the loading plane. Obviously, it is also possible to pretension both pivotal arms towards the center of the loading plane. 
     A further advantageous embodiment of the invention is characterized in that the coupling rod has at least two longitudinal grooves which are each engaged by a pivotal-arm pin mounted on the pivotal arm, and the coupling rod has at least one coupling-rod pin which engages a housing-cover groove which extends in a housing cover in the direction of the rectilinear loading path. 
     This construction ensures that the coupling rod moves along the straight-line loading path. As a result, the two pivotal arms are pivoted symmetrically and the supporting guide and the loading guide guide the information disc along the straight-line loading path during loading and unloading. 
     A further advantageous embodiment of the invention is characterized in that the supporting guide takes the form of a rotationally drivable transport wheel. 
     The rotatable construction of the supporting guide makes it possible to insert and remove the information disc into/from the apparatus without the information disc itself being rotated. If the transport wheel of the supporting guide and the transport wheel of the loading guide are grooved, the information disc will be moved into and out of the apparatus without rotation of the disc itself if the groove diameter of the transport wheel of the supporting guide and the transport wheel of the loading guide is the same and the transport wheel of the supporting guide and the transport wheel of the loading guide rotate with the same speed in opposite directions of rotation. 
     A further advantageous embodiment of the invention is characterized in that the transport wheel has a groove in which the disc edge of the information disc is engageable. 
     A further advantageous embodiment of the invention is characterized in that the supporting guide has a groove in which the disc edge of the information disc is engageable. 
     A groove is a particularly simple possibility of guiding the disc edge. 
     A further advantageous embodiment of the invention is characterized in that the transport wheel comprises a supporting surface adapted to support one side of the disc edge of the information disc, the transport wheel has a contact edge against which the edge of the information disc can be pressed, and there has been provided a pressure element adapted to be pressed against the other side of the disc edge of the information disc. 
     Such a construction enables a large holding force in a direction perpendicular to the loading plane to be applied to the disc surface at the location of the disc edge of the information disc. This is particularly important in an eject position, in which the information disc projects farthest from the housing and the information disc must be held only by means of the supporting guide and the loading guide to allow it to be removed by the user. 
     A further advantageous embodiment of the invention is characterized in that the supporting guide comprises a supporting surface adapted to support one side of the disc edge of the information disc, the supporting guide has a contact edge against which the edge of the information disc can be pressed, and there has been provided a pressure element adapted to be pressed against the other side of the disc edge of the information disc. 
     A further advantageous embodiment of the invention is characterized in that there has been provided an auxiliary guide which enables the disc edge of the information disc to be additionally guided in an intermediate stage of the loading process. 
     The auxiliary guide prevents the information disc from being tilted relative to the loading plane. The auxiliary guide is no longer operative in a final stage of the loading operation, so that the information disc can be lowered onto a turntable. 
     The loading mechanism is preferably used in a deck, in an apparatus for recording and/or reproducing of information on/from an information disc by means of a deck, and in a car radio comprising a deck. 
    
    
     Those skilled in the art will understand the invention and additional objects and advantages of the invention by studying the description of preferred embodiments below with reference to the following drawings which illustrate the features of the appended claims: 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Some embodiments of the invention will be described in more detail hereinafter, by way of examples, with reference to FIGS. 1 to  13 , in which: 
     FIG. 1 shows as a first embodiment the loading mechanism of an apparatus for recording and/or reproducing information on/from an information disc in a plan view, the loading mechanism having pivotal arms carrying guides for the edges of the information disc and being shown in an eject position in which the information disc is held in a stable manner by the guides and can be removed by hand by a user, 
     FIG. 2 shows the loading mechanism of FIG. 1 in an intermediate position in which the user has inserted the information disc up to a point at which the loading mechanism automatically takes over the further insertion of the information disc, 
     FIG. 3 shows the loading mechanism of FIG. 1 in a roll-in position with an information disc wholly rolled-in in a first loading direction, 
     FIG. 4 is a front view of the loading mechanism shown in FIG. 3, 
     FIG. 5 is a perspective view showing the loading mechanism with the information disc in the eject position and the roll-in position, 
     FIG. 6 shows as a second embodiment the loading mechanism of an apparatus for recording and/or reproducing information on/from an information disc in a plan view, the loading mechanism being shown in an eject position and the pivotal arms being coupled by a coupling rod, 
     FIG. 7 shows the loading mechanism of FIG. 6 in an intermediate position in which the user has inserted the information disc up to a point at which the loading mechanism automatically takes over the further insertion of the information disc, 
     FIG. 8 shows the loading mechanism of FIG. 6 in a roll-in position with an information disc wholly rolled-in in the first loading direction, the guides arranged on the pivotal arms being pivoted away from the disc edge to allow the information disc to be lowered onto a turntable by means of a lowering mechanism, not shown, 
     FIG. 9 is a front view of the loading mechanism shown in FIG. 8, 
     FIG. 10 is a perspective view showing the loading mechanism with the information disc in the eject position and the roll-in position, a supporting guide not being shown to illustrate the construction of an auxiliary guide more clearly, 
     FIG. 11 is a sectional view of a transport wheel, 
     FIG. 12 is a sectional view of another example of the transport wheel, 
     FIG. 13 is a side view of a further example of the transport wheel. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     A first embodiment of a loading mechanism of an apparatus for recording and/or reproducing signals/information shown in FIG. 1 is accommodated in a housing  1 . The loading mechanism serves for loading/unloading an information disc  2  which stores the signals/information. The information disc  2  has a circular edge  2   a  and has a circular positioning hole  3  with an edge  3   a.  The housing  1  has a front wall  4   a,  a rear wall  4   b  and side walls  4   c  and  4   d.  As is shown in FIG. 4, the housing comprises a bottom plate  4   e  and a cover plate  4   f.  The front wall  4   a  has a loading slot  5 , visible in FIG. 4, through which the information disc  2  can be inserted. As is shown in FIG. 1, a pivotal spindle  8  is mounted on the bottom plate  4   e  in the proximity of the side wall  4   c,  about which spindle a first pivotal arm  7  is pivotable. The pivotal arm  7  carries a supporting guide  9  having a groove  10 . The supporting guide  9  can, for example, be made of rubber. A further pivotal spindle  13  is mounted on the bottom plate  4   e  in the proximity of the side wall  4   d , about which spindle a second pivotal arm  12  is pivotable. The pivotal arm  12  carries three toothed wheels  14 ,  15  and  16  which mesh with one another. The toothed wheel  14  is rotatably journaled on the spindle  13 . The toothed wheels  15  and  16  are journaled on spindles  17  and  18  mounted on the pivotal arm  12 . In FIG. 4 a  transport wheel in the form of a rubber roller  21  is connected to the toothed wheel  16  by a connecting member  20 . The rubber roller  21  has a groove  22 . The groove  22  of the rubber roller  21  and the groove  10  of the supporting guide  9  extend in a loading plane  43 . The rubber roller  21  may also consist of another material. 
     A motor  24 , whose shaft  25  carries a worm  26 , is mounted on the bottom plate  4   e  of the housing  1 . The motor  24  can be driven in two directions. By means of the worm  26  a toothed wheel  27  can be driven, which toothed wheel is rotatably mounted on a spindle  28  carried by the bottom plate  4   e.  The toothed wheel  27  is in mesh with the toothed wheel  14 . Thus, the rubber roller  21  can be driven in two directions by means of the motor  24 , the shaft  25 , the worm  26  and the toothed wheels  27 ,  14 ,  15  and  16 . 
     The free ends  7   a  and  12   a  of the pivotal arm  7  and the pivotal arm  12  are connected to one another by means of a tension spring  30 , as a result of which a force directed towards the center of the housing  1  is exerted on the free ends  7   a  and  12   a  of the pivotal arms  7  and  12 . 
     Moreover, two stops  31  and  32  are disposed on the rear wall  4   b  of the housing  1  at the level of the loading plane  43 . 
     The insertion of the information disc  2  into the housing  1  will now be explained with reference to FIGS. 1 to  4 . 
     When the information disc  2  is to be loaded into an apparatus, a user holds the information disc  2  at the edge  3   a  of the positioning hole  3  and at the periphery  2   a  of the information disc  2 . The information disc  2  thus held is inserted into the grooves  10  and  22  of the supporting guide  9  and the rubber roller  21  through the slot  5  in the front wall  4   a  of the housing  1 . This position of the information disc  2  is shown in FIG.  1  and is referred to as the eject position. The user then moves the information disc  2  by hand in the direction indicated by an arrow  35  into a position referred to hereinafter as the intermediate position over a length indicated by  36  in FIG.  1 . This length is of the order of magnitude of 40 mm, i.e. approximately ⅓ of the diameter of the information disc, but other lengths are also possible. The information disc  2  is then laterally guided by the groove  10  of the supporting guide  9  at one side and by the groove  22  of the rubber roller  21  at the other side, the surface of the information disc  2  not being touched by the user&#39;s hand. The pivotal arm  12  is then pivoted about the spindle  13  and the pivotal arm  7  about the spindle  8 . The pivoting angle is determined by the outline of the information disc  2 . 
     FIG. 2 shows the position of the information disc  2  in the intermediate position. In this intermediate position the information disc  2  and, consequently, the positioning hole  3 , projects from the front  4   a  of the housing  1  over approximately ⅔ of the diameter of the information disc. As a result of this, the user can also hold the information disc  2  at the edge  3   a  of the positioning hole  3  and at the periphery  2   a  of the information disc  2  in this intermediate position. 
     When the information disc  2  has been inserted into the apparatus up to this intermediate position, the motor  24  is energized via a switch, not shown, and the loading mechanism automatically performs further insertion of the information disc  2 . 
     The switch can be, for example, a mechanical switch or an optical switch (light barrier). It is also possible to start the motor at an earlier instant. 
     The motor now begins to rotate so as to drive the rubber roller  21  clockwise via the shaft  25 , the worm  26 , the toothed wheels  27 ,  14 ,  15  and  16 . The rubber roller  21 , which rotates clockwise, then exerts a tangential force on the edge of the information disc  2 , as a result of which the information disc  2 , which is supported between the supporting guide  9  and the rubber roller  21 , is automatically rolled into the housing along a straight loading path  45 . The pivotal arm  12  is then pivoted about the spindle  13  and the pivotal arm  7  about the spindle  8 . 
     The roll-in operation is stopped in that the edge of the information disc  2  abuts against the two stops  31  and  32  arranged on the rear wall  4   b  of the housing  1 . This position of the information disc  2  is shown in FIG.  3  and is referred to hereinafter as the roll-in position. The motor  24  is now switched off by means of a switch, not shown. Again, the switch can be, for example, a mechanical switch or an optical switch (light barrier). 
     Thus, the automatic roll-in operation of the information disc has ended and a positioning process can be started, in which the information disc  2  is lowered with its positioning hole  3  onto holding elements  37  of a turntable (similar to  91  in FIG. 9 for another embodiment). The information disc  2  is then clamped onto the turntable by means of a clamping device (similar to  90  in FIG. 9 for another embodiment), and the information disc  2  now occupies a position, not shown and referred to hereinafter as the play position. The positioning process during loading can be as described comprehensively in (EP 273,510) hereby incorporated in whole by reference), but different positioning processes are also possible. 
     The ejection process now proceeds as follows. First of all, the information disc  2  is lifted from the play position into the roll-in position by means of the positioning mechanism. 
     The motor  24  is now started and is rotated so as to drive the rubber roller  21  counter-clockwise. The rubber roller  21 , which rotates counter-clockwise, exerts a tangential force on the edge  2   a  of the information disc  2 , as a result of which the information disc  2 , which is supported between the supporting guide  9  and the rubber roller  21 , is automatically rolled out of the housing along the straight loading path  45 . The information disc  2  is then laterally guided by the groove  10  of the supporting guide  9  at one side and by the groove  22  of the rubber roller  21  at the other side and the pivotal arm  12  is pivoted about the spindle  13  and the pivotal arm  7  about the spindle  8 . The information disc  2  is now automatically moved outward into the eject position shown in FIG.  1  and the motor  24  is switched off by the switch, not shown. 
     In this eject position the information disc  2  is held in a stable manner by the rubber roller  21  and the supporting guide  9  so as to prevent the information disc  2  from inadvertently rolling out of the housing  1 . In this eject position the user can remove the information disc  2  by hand at the edge  3   a  of the positioning hole  3  and at the periphery  2   a  of the information disc  2 . 
     FIG. 5 is a perspective view of the loading mechanism, the information disc  2  being shown in the eject position and the roll-in position. 
     FIG. 6 shows a second embodiment of a loading mechanism in accordance with the invention in the eject position. The loading mechanism shown in FIG. 6 is accommodated in a housing  51 . The loading mechanism serves to move an information disc  52  into the housing  1  in a first loading direction  55  along a straight loading path  54  and out of the housing  1  in a direction opposite to the first loading direction  55  along the straight loading path  54 . The information disc  52  has a circular edge  52   a  and has a circular positioning hole  53  with an edge  53   a.  The housing  51  has a front wall  56   a , a rear wall  56   b  and side walls  56   c  and  56   d,  as well as a bottom plate  56   e  (see FIG. 9) and a housing cover  56   f  (see FIG.  9 ). A pivotal spindle  58  is mounted on the bottom plate  56   e  in the proximity of the side wall  56   c,  about which spindle a first pivotal arm  57  is pivotable. A spindle  60  is mounted on the housing bottom  56   e  in the proximity of the side wall  56   d,  about which spindle a second pivotal arm  59  is pivotable. The first pivotal arm  57  carries a pivotal-arm pin  61  and a supporting guide  62  having a groove  63 . The second pivotal arm  59  carries a transport wheel  66  which is rotatable about a spindle  67 . The transport wheel  66  has a groove  68 . A motor  69 , whose shaft  69   a  carries a worm  70 , is mounted on the bottom plate  56   e  of the housing  51 . The motor  69  can be driven in two directions. By means of the worm  70  a toothed wheel  71  can be driven, which toothed wheel is rotatable about a spindle  71   a  carried by the bottom plate  56   e.  The toothed wheel  71  is in mesh with a toothed wheel  72 , which is rotatable about the pivotal spindle  60  of the second pivotal arm  59 . The second toothed wheel  72  is in mesh with a third toothed wheel  73 , which is rotatable about a spindle  73   a  carried by the second pivotal arm  59 . The third toothed wheel  73  meshes with a toothed ring  74  arranged on the transport wheel  66 . Thus, the transport wheel  66  can be driven in two directions by means of the motor  69 , the motor shaft  69   a,  the worm  70 , the first toothed wheel  71 , the second toothed wheel  72 , the third toothed wheel  73  and toothed ring  74  on the transport wheel. 
     A T-shaped coupling rod  76  has a first coupling-rod groove  77 , which extends perpendicularly to the first loading direction  55 , a second coupling-rod groove  78 , which extends perpendicularly to the first loading direction  55 , a first coupling-rod pin  79  and a second coupling-rod pin  80 . The first coupling-rod pin  79  and the second coupling-rod pin  80  engage a housing-cover groove  81  formed in the housing cover  56   f  and extending in the first loading direction  55 . The pivotal-arm pin  61  of the first pivotal arm  57  engages the first coupling-rod groove  77  and the pivotal-arm pin  64  of the second pivotal arm  59  engages the second coupling-rod groove  78 . 
     The first pivotal arm  57  is pretensioned in the direction indicated by an arrow  82  about the pivotal spindle  58  by means of a spring, not shown. The second pivotal arm  59  is pretensioned in the direction indicated by an arrow  83  about the pivotal spindle  60  by means of a spring, not shown. It is also possible to pretension only one of the two pivotal arms. 
     The rear wall  56   b  of the housing  51  carries two stops  84  and  85 . 
     The side wall  56   c  of the housing  51  carries an auxiliary guide  86 . This auxiliary guide  86  has a lower supporting surface  86   a,  which extends in a loading plane  75 , and an upper guide surface  86   b,  which extends in the loading plane  75 . The upper guide surface  86   b  is longer than the lower supporting surface  86   a  in the first loading direction  55 . 
     In the eject position shown in FIG. 6 the user has brought the information disc  52  by hand into engagement with the groove  63  of the supporting guide  62  and the groove  68  of the transport wheel  66 . For this purpose, the user holds the information disc  52  by the edge  52   a  of the disc  52  and by the edge  53   a  of the positioning hole  53 . The information disc  52  thus held is moved from the eject position shown in FIG. 6 into the intermediate position shown in FIG.  7 . During this movement from the eject position shown in FIG. 6 into the intermediate position shown in FIG. 7 the first pivotal arm  57  is pivoted about the spindle  58  and the second pivotal arm  59  is pivoted about the spindle  60 . The pivoting force required for this is exercised by the user. The information disc  52  is then laterally guided by the groove  63  of the supporting guide  62  at one side and by the groove  68  of the transport wheel  66  at the other side. The user does not touch the surface of the information disc  52 . 
     In the intermediate position of the loading mechanism shown in FIG. 7 the information disc  52  projects from the front  56   a  of the housing  51  over approximately ⅔ of its diameter. As is shown in FIG. 7, it is possible to mount a control panel  88  on the front wall  56   a  of the housing  51 . This control panel  88  can be, for example, the control panel of a car radio which incorporates an apparatus for recording and/or reproducing information on/from the information disc  52 . The positioning hole  53  of the information disc  52  projects from the front side  88   a  of the control panel  88 . Consequently, the user can also hold the information disc  52  by the edge  53   a  of the positioning hole  53  and by the edge  52   a  of the information disc  52  in this intermediate position. 
     When the user has inserted the information disc  52  by hand into the housing  51  up to the intermediate position, the motor  69  is energized via a switch, not shown, and the loading mechanism automatically completes the loading process. 
     The switch can be, for example, a mechanical switch or an optical switch (light barrier). It is also possible to start the motor at an earlier instant. 
     The motor  69  now begins to rotate so as to drive the transport wheel  66  clockwise via the motor shaft  69   a,  the worm  70 , the first toothed wheel  71 , the second toothed wheel  72 , the third toothed wheel  73  and toothed ring  74  on the transport wheel. The transport wheel  66 , which rotates clockwise, then exerts a tangential force on the edge  52   a  of the information disc  52 , as a result of which the information disc  52 , which is supported between the supporting guide  62  and the transport wheel  66 , is automatically rolled into the housing  51  along a straight loading path  54 . The first pivotal arm  57  is then pivoted about the spindle  58  and the second pivotal arm  59  about the spindle  60 . 
     FIG. 8 shows the loading mechanism in a roll-in position, in which the information disc  52  has been moved up to the stops  84  and  85  in the first loading direction  55 . The pivotal arms  57  and  59  have been pivoted away from the disc edge  52   a  with the transport wheel  66  and the supporting guide  62  and the lower supporting surface  86   a  of the auxiliary guide  86  no longer acts upon the information disc  52 , so that by means of a lowering mechanism, not shown, this information disc can be lowered with its positioning hole  53  onto a clamping device  90  of a turntable  91  shown in FIG. 9 into a play position, not shown. In this play position, not shown, the information disc  52  can be rotated by means of the turntable  91 , which is drivable by drive means  96  shown in FIG. 9, and the information stored on the information disc  52 , for example music information, can be reproduced. 
     The transfer from the intermediate position shown in FIG. 7 to the roll-in position shown in FIG. 8 will be described in detail hereinafter. 
     The transport wheel  66 , which rotates clockwise, exerts a tangential force on the edge  52   a  of the information disc  52 , as a result of which the information disc  52 , which is supported between the supporting guide  62  and the transport wheel  66 , is rolled into the housing  51  along a straight loading path  54  in the first loading direction  55 . 
     During the movement from the intermediate position to the play position the edge  52   a  of the information disc  52  is partly guided by the auxiliary guide  86 , which as a third guide in addition to the supporting guide  62  and the transport wheel  66  forming the loading guide which ensures a better guidance of the information disc  52 . 
     In a first part  92  of the auxiliary guide  86 , indicated in FIGS. 7 and 8, the edge of the information disc  52  is then guided both by the lower supporting surface  86   a  of the auxiliary guide  86  and by the upper guide surface  86   b  of the auxiliary guide  86 . In a second part  93  of the auxiliary guide  86  the information disc  52  is guided only by the upper guide surface  86   b  of the auxiliary guide  86 . During the movement of the information disc  52  in the first loading direction  55  rolling-in along the straight loading path  54  is achieved in that the first coupling-rod pin  79  and the second coupling-rod pin  80  are guided in the first loading direction  55  in the housing-cover groove  81 . The loading process in the first loading direction  55  is terminated in that the information disc  52  abuts against stops  84  and  85  on the rear wall  56   b  of the housing  51 . Once the information disc  52  has been moved against the stops  84  and  85  in the first loading direction  55 , a drive mechanism, not shown, is activated in a manner, not shown, which mechanism acts upon the first pivotal arm  57  in such a manner that this arm is pivoted clockwise about the pivotal spindle  58  and upon the second pivotal arm  59  in such a manner that this arm is pivoted counter-clockwise about the spindle  60 . 
     As a result, the groove  68  of the transport wheel  66  and the groove  63  of the supporting guide  62  are disengaged from the edge  52   a  of the information disc  52 . In this position the information disc  52  is no longer guided by the lower supporting surface  86   a  of the auxiliary guide  86 . This enables the information disc  52  as shown in FIG. 9 to be lowered onto the clamping device  90  of the turntable  91  in a manner, not shown, by a lowering mechanism, not shown, in a second loading direction  95  perpendicular to the loading plane  75 . The unloading process is exactly the inverse of the loading process. 
     FIG. 9 shows the loading mechanism in the roll-in position of FIG. 8 in a front view at the front wall  56   a  of the housing  51 . The turntable  91  can be driven by means of a disc-drive motor  96 , so that the information disc  52 , when it has been clamped onto the clamping device  90  of the turntable  91  with its positioning hole  53 , can also be rotated by means of the disc-drive motor  96 . 
     FIG. 10 shows the loading mechanism in a perspective view with the information disc  52  in the eject position and in the roll-in position. The first pivotal arm  57  is not shown to illustrate the construction of the auxiliary guide  86  with the lower supporting surface  86   a  and the upper guide surface  86   b  more clearly. 
     FIG. 11 is a sectional view of an example of the transport wheel  66 . The transport wheel  66  comprises a rubber body  97  in which the groove  68  of the transport wheel  66  has been formed. The rubber body  97  surrounds a spindle  98 , which may for example consist of a metal or a plastic. 
     The rubber body  97  further has a toothed ring  74 , which has for example been pressed onto the rubber body  97  or which has for example been secured to the spindle  98 , thereby enabling the transport wheel  66  to be rotated by a toothed wheel, not shown in FIG. 11, which toothed wheel meshes with the toothed ring  74 . 
     FIG. 12 shows a slightly different construction of the transport wheel  66  of FIG.  11 . The rubber body  97  of the transport wheel  66  has two oil-filled oil chambers  100  and  101  adjoining the groove  68 . 
     When an information disc not shown in FIG. 12 is inserted into the grooves  68 , the oil chambers  100  and  101  of the rubber body  97  can engage with the disc edge. This enables larger forces for holding the information disc to be applied. 
     FIG. 13 shows a transport wheel  103  having a supporting surface  104 , which supports the surface  102   a  of an information disc  102 . The transport wheel  103  has a contact edge  105  against which the edge  102   c  of the information disc  102  bears. A pressure element  106  has been provided, which is mounted on a member  107  so as to be movable in the direction indicated by an arrow  108 . The pressure element  106  is pretensioned relative to the member  107  in the direction indicated by the arrow  108 . As a result of this pretension, which can for example be obtained by means of a spring not shown, the pressure surface  106   a  of the pressure element  106  is pressed against the surface  102   b  of the information disc  102 . 
     By means of such a construction a larger clamping force can be exerted on the information disc  102  than is possible by means of a groove  68  of the transport wheel  66  as shown in FIGS. 11 and 12. Such a larger clamping force is of particular importance in the eject position. Obviously, it is also possible to use the construction shown in FIG. 13 for the supporting guide  62 . 
     The invention has been disclosed with reference to specific preferred embodiments, to enable those skilled in the art to make and use the invention, and to describe the best mode contemplated for carrying out the invention. Those skilled in the art may modify or add to these embodiments or provide other embodiments without departing from the spirit of the invention.