Disk-cassette loading mechanism

Abstract: In a disk-cassette loading mechanism having such cassette withdrawing means (33) as to be engaged with an inserted disk cassette (1) to automatically withdraw the inserted disk cassette (1) into a predetermined position, the cassette withdrawing means (33) can be disengaged from the disk cassette (1) to easily draw out the cassette (1) from the mechanism (33) when the disk cassette (1) is drawn by hand in opposition to a direction for withdrawing the disk cassette (1) after an engaging portion (36) of the cassette withdrawing means (33) is engaged with an engaged portion (6) of the inserted disk cassette (1).

Description: Field of the Invention This invention relates to a disk-cassette loading mechanism, which has cassette withdrawing means to be engaged with an inserted disk cassette, and automatically withdraw it into a predeterminted position. Description of the Prior Art Disclosed in Japanese Laid Open Patent No.63-71975 is a disk-cassette loading mechanism, in which an engaging portion of a cassette withdrawing arm is engaged with an engaged recess of the disk cassette when a disk cassette is inserted toward a disk drive, and then, the cassette withdrawing arm is moved in a direction for withdrawing the disk cassette by the help of cam means driven by a motor. Thus, the disk cassette is located in the cassette loading position. In such disk-cassette loading mechanism, the inserted disk cassette is withdrawn into the mechanism and automatically loaded in the cassette loading position, but the disk cassette can not be drawn out from the mechanism without depending upon a regular ejecting operation, after the motor begins to rotate. In the meantime, it is often desired to change an inserted disk cassette to another one in the course of inserting the disk cassette into the mechanism, so that the above disk-cassette loading mechanism will be inconvenient for use. In EP 0 156 569 A1 describes a disk-cassette loading mechanism having a cassette withdrawing means. In this mechanism the cassette abuts against one of two arms of an L-shaped withdrawing means during insertion, and the L-shaped withdrawing means is thereby rotated against the force of a torsion spring. At the free end of the second arm of the L-shaped withdrawing means a projection is provided. The rotation of said withdrawing means causes an engaging of the projection in a recess provided in a corresponding position in the cassette. Due to the engaging the cassette is now withdrawable by moving the withdrawing means. In order to keep the L-shaped withdrawing means engaged in the recess of the cassette a slidable bolt is provided which is slided up from a lower bolt position to an upper bolt position as soon as the L-shaped withdrawing means has begun withdrawing the cassette into a final position. The bolt is moved together with the withdrawing means so that the latter is kept bolted against the force of the torsion spring. For ejecting the cassette it is moved together with the withdrawing means in an ejecting direction, the withdrawing means still being kept bolted by the bolt which is also moved back together with the withdrawing means. In an ejecting position the bolt is slided back in the lower bolt position releasing the withdrawing means in order to disengage the projection. Simultaneously, the first arm of the withdrawing means pushes the cassette outwards to complete the ejection. OBJECTS AND SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a disk-cassette loading mechanism in which an engaging portion of cassette withdrawing means for automatically withdrawing an inserted disk cassette into a predetermined position is reliably disengaged from an engaged portion of the disk cassette, even if when the disk cassette is drawn by hand in opposition to a direction for withdrawing the disk cassette. In accordance with an aspect of this invention, in a disk-cassette loading mechanism having cassette withdrawing means to be engaged with an inserted disk cassette and to withdraw it automatically into a predetermined position, the cassette withdrawing means is so provided as to be rotatable on a pivot which is provided in driving means; biased urging means for rotatively urging the cassette withdrawing means in a direction for engaging an engaging portion of the cassette withdrawing means with an engaged portion of the disk cassette; the pivot driven by the driving means is moved in a direction for withdrawing the inserted disk cassette so as to automatically withdraw the disk cassette into the predetermined position after the engaging portion of the cassette withdrawing means is engaged with the engaged portion of the disk cassette; and whereby disengaging means for disengaging the engaging portion of the cassette withdrawing means from the engaged portion of the disk cassette is provided comprising a stationary stopper which abuts a part of the cassette withdrawing means such that the cassette withdrawing means is rotatively moved against the biased force of the urging means by a force exerted on the cassette withdrawing means, when the disk cassette is drawn in opposition to the direction for withdrawing the inserted disk cassette. Due to the fact that during ejection of a cassette the withdrawing means pushes against the stationary stopper such that the cassette withdrawing means is rotatively moved against the biased force of the urging means, the engaging portion is reliably disengaged from an engaged portion of the disk cassette even if the disk cassette is drawn by hand in an ejection direction. Moreover, in an advantageous embodiment the driving means is so provided as to be rotatable on a shaft; second urging means is provided for rotatively urging the driving means to move the pivot in the direction for withdrawing the disk cassette; locking means is provided to lock the driving means in a position from which the driving means begins to withdraw the cassette withdrawing means; and when the driving means is unlocked, the pivot, which is integral with the driving means, is moved in the direction for withdrawing the disk cassette due to force of the second urging means. The driving means is unlocked due to a motion of the locking means which is caused by a push given by the inserted disk cassette, and it is substantially simultaneous with the engagement of the cassette withdrawing means with the disk cassette. Further, shutter opening and shutting means is provided to open a shutter, which is secured to the disk cassette, as the disk cassette is inserted, and shut the shutter on the one hand and push out the disk cassette on the other hand as the disk cassette is ejected; and the engaged portion of the disk cassette is engaged with the engaging portion of the cassette withdrawing means and substantially at the same time, the locking means is moved by the shutter opening and shutting means in a direction for unlocking the drive means. In addition, in the cassette loading mechanism, a slider is so provided as to be slidingly driven by the driving means to be lowered from the upper position to the lower position thereof while the driving means moves the pivot in the direction for withdrawing the disk cassette, so that in the lower position, a recording disk accommodated in the disk cassette is mounted on a turntable and simultaneously, faces a reader. The above, and other objects, features and advantages of this invention, will be apparent from the following detailed description of illustrative embodiments thereof to be read in connection with the accompanying drawings wherein like reference numerals identify the same or corresponding parts in the several views. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a plan view of a disk-cassette loading mechanism according to an embodiment of this invention; Figure 2 is a plan view, partly broken away, of the disk-cassette loading mechanism of Figure 1; Figure 3 is a sectional view on an enlarged scale and taken along the line III-III on Figure 1; Figure 4 is a bottom plan view, partly omitted, of the disk cassette loading mechanism of Figure 1; Figure 5A to 5F are plan views for illustrating in turn the operation of the cassette loading mechanism of Figure 1; Figure 6 is a sectional view taken along the line VI-VI on Figure 5F; Figure 7 is a schematic plan view for illustrating positional relationships among principal parts of the disk-cassette loading mechanism of Figure 1; Figure 8 is a schematic plan view for illustrating an operation of the disk-cassette loading mechanism of Figure 1 at the time when the disk cassette is drawn out from the mechanism in opposition to a direction for withdrawing the disk cassette; and Figure 9 is a schematic plan view for illustrating an operation of the disk-cassette loading mechanism of Figure 1 at the time when the disk cassette is regularly unloaded. DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT Referring to the drawings in detail, a disk-cassette loading mechanism embodying the present invention will be described. A disk cassette 1 supplied to the loading mechanism is of flat shape and accommodates a recording disk 2 as shown in Figure 5F. A shutter 3 is slidably secured to one end of the disk cassette 1, and held in the shut position thereof by resilent means (not shown) as illustrated in Figure 1. When the shutter 3 is moved to the open position thereof, an opening 4 provided in the bottom of the disk cassette 1 is opened, and through the opening 4, the recording disk 2 is exposed. Reference numerals 5 and 6 in Figure 1 denote a groove and a recess, respectively. A further detailed description of the disk cassette will be omitted, as there is hardly any point in relation to the subject matter of this invention (if necessary, see U.S.P. No.4,746,013, for example). As shown in Figure 1, mounted on a chassis 7 of the disk-cassette loading mechanism are a turntable 8 on which the disk 2 is mounted so as to be turned, an optical reader 9 for reading information from the disk 2, and so forth. Four guide pins 10 which uprightly project from the chassis 7 are fitted into respective insertion holes 14 provided in a cassette table 13, so that the cassette table 13, which is horizontally positioned in parallel with the chassis 7, is movable to be approached to, and separated from the chassis 7 along the guide pins 10. Further, four tension springs 15 are stretched between the chassis 7 and the cassette table 13 so that the cassette table 13 may be urged in a direction for being approached to the chassis 7. It is noted that the cassette table 13 is substantially a box frame (Figure 1). As shown in Figure 3 and 1, between the chassis 7 and the cassette table 13, there is placed a slider 45 which is substantially a box frame comprising two longitudinal beams 47 and 48 and two cross beams 46 and 49, and is formed by press working of sheet metal. In the slider 45, there are three elongate holes 50 extending along the longitudinal beams 47 and 48, and in the elongate holes 50, three guide pins 51, which project downwards from the cassette table 13, are loosely fitted, respectively, and the free ends of the guide pins 51 are enlarged lest the guide pins 51 should come out. Thus, the slider 45 is slidable on the lower face of the cassette table 13 within a movable extent of the pin 51 in the elongate hole 50. As shown in Figure 3 and 1, the slider 45 has four brackets 52 on the lower face thereof to rotatably support respective rollers 53. The brackets 52 are made of synthetic resin, and the rear faces 52 a of the brackets 52 are formed into a slope. The rollers 53 roll on the upper face of the chassis 7, and as shown in Figure 6, can roll down on slopes 12 provided in the chassis 7. The slopes 12 are formed so as to be inclined downwards in respective elongate holes 11, which are provided in the chassis 7 (Figure 1). Thus, when the rollers 53 are not on the slopes 12 (Figure 3), the cassette table 13 mounted on the slider 45 is located in a first position which is spaced away upwards from the chassis 7, and when the rollers 53 are on the slopes as shown in Figure 6, the cassette table 13 is located in a second position which is adjacent to the chassis 7. A cassette guiding portion 16 shown in Figure 1 has a pair of right and left guide ways 17 which are connected with each other through a connecting plate 18, and are disposed on the upper face of the cassette table 13 to guide the disk cassette 1, which is supplied to the disk-cassette loading mechanism. A shutter opening lever 19 is rotably secured to the upper face of the cassette table 13 at the proximal end thereof, and is urged clockwise in Figure 1 due to force of a torsion spring 20 so far that the lever 19 abuts against a stop 21 (Figure 2). In such position, the lever 19 inclines inwardly as shown in Figure 1. Further, a roller 22 is rotatably secured to the distal end of the lever 19. A holding means for holding the cassette 1 comprises a cassette withdrawing arm 33 which has a convex 36 provided at the distal end of the arm portion 34 thereof and capable of engaging the recess 6 of the cassette 1, a cassette withdrawing lever 24 which is rotatably secured to the cassette table 13 and has a pivot 32, on which the cassette withdrawing arm 33 rotates, and a locking lever 40 for locking the cassette withdrawing lever 24. The cassette withdrawing lever 24 is made of sheet metal, and substantially has the shape of the letter "T": a central projection 25, a right projection 27, and a left projection 26. The projections 26 and 27 are gradually widened toward the proximal end thereof, as if a gusset were inserted between the central projection 25 and each of the right and left projections 26 and 27. The lever 24 is rotatably supported in the intermediate position of the left projection 26 by a shaft 28 which projects from the upper face of the cassette table 13, and is urged counterclockwise in Figure 1 by the force of a tension spring 29 which is stretched between the free end of the central projection 25 and the rear end of the cassette table 13. The free end of the left projection 26 of the cassette withdrawing lever 24 abuts against a pin 30 which projects upwards from the slider 45, and passes through a slot 31 which is provided in the cassette table 13. The cassette withdrawing arm 33 has a projection 35 at the proximal end thereof, and is urged clockwise in Figure 1 by the force of a tension spring 37, which is stretched between the free end of the projection 35 and a spring anchor 38 projecting from substantially the midst of the central projection 25, so far that the free end of the projection 35 abuts against a stop 39. The spring constant of spring 29 is much larger than that of spring 37. The locking lever 40 is rotatably supported by a shaft 41 in the intermediate position thereof, and urged clockwise an in Figure 1 by the force of a torsion spring 42. The shaft 41 projects from the upper face of the cassette table 13. At the rear end of the locking lever 40, there is a steplike notch 43, and at the forward end of the locking lever 40, there is a pin 44, which can abut the shutter opening lever 19. When the holding means 23 is in its initial position as shown in Figure 1, the pin 30 is sandwiched between the free end of the left projection 26 of the cassette withdrawing lever 24 and the steplike notch 43 of the locking lever 40, and the cassette table 13 is in the first position thereof, because the rollers 53 of the slider 45 are not on the slopes 12 of the chassis 7. As shown in Figures 1 and 4, a damper 57 is secured to the cassette table 13, and a pinion 58 is secured to a shaft 57a which projects from the damper 57. The pinion 58 is meshed with a rack 56 which projects rearwards from the rear cross beam 46 of the slider 45. As shown in Figures 1 and 2, an unloading mechanism 59 comprises a gear 60 which is rotatably supported by the cassette table 13, a motor 61 by which the gear 60 is driven, and an inverse cam means 54 which comprises an eccentric pin 62 projecting from the gear 60, and a cam face 55 provided in the slider 45. The cam face 55 comprises a first straight portion 55 a , a second straight portion 55 b , and an intermediate curved portion 55 c . The function of the disk-cassette loading mechanism will be hereinafter described. When loaded, the disk cassette 1 is inserted into the cassette guiding portion 16 of the cassette table 13 as shown in Figure 5A, and at that time, the cassette table 13 is in the first position thereof. As the cassette 1 is advanced, the roller 22 of the shutter opening lever 19 is fitted into the groove 5 of the cassette 1 (Figure 5B) to move the shutter 3 in a direction of arrow a . Soon after, the convex 36 of the cassette withdrawing arm 33 comes in contact with a corner of the cassette 1, and is pushed by the cassette 1, so that the arm 33 is rotated a little counterclockwise in Figure 5C against the force of the tension spring 37, and abuts against a side of the cassette 1, which is parallel to the advance direction of the cassette 1. Then, the convex 36 of the cassette withdrawing arm 33 is fitted in the recess 6 of the cassette 1 (Figure 5D), and simultaneously, the free end of the shutter opening lever 19 is abutted the pin 44 of the locking lever 40. Due to successive rotation of the shutter opening lever 19, the locking lever 40 is rotated to disengage the steplike notch 43 thereof from the pin 30, so that the slider 45 and the cassette withdrawing lever 24 of the holding means 23 are unlocked (Figure 5E). Thus, the cassette withdrawing lever 24 is rotated in the direction of arrow c in Figure 5E due to force of the tension spring 29, and the pivot 32 is revolved around the shaft 28 to withdraw the cassette 1 in the direction of arrow b through the cassette withdrawing arm 33 (Figure 5F). On the other hand, the slider 45 is moved in the direction of arrow b ′ in relation to the cassette table 13 and the chassis 7, because the pin 30 of the slider 45 is pushed by the cassette withdrawing lever 24, so that the cassette table 13 descends to the second position thereof as shown in Figure 6. When the cassette table 13 reaches the second position thereof, the shutter 3 is completely opened by the shutter opening lever 19. As the result, the disk 1 is mounted on the turntable 8, and the reader 9 faces the disk 1, so that the cassette loading operation is accomplished. When the cassette 1 is unloaded, the gear 60 is driven in a direction of arrow d in Figure 2 in response to a command signal, and the eccentric pin 62 comes in contact with the first straight portion 55 a of the cam face 55 as indicated in dotted lines in Figure 9, and pushes the slider 45 in the direction of arrow b through the inverse cam means 54 of the slider 45. Thus, the slider 45 moves toward the position shown in Figure 3, and the cassette table 13 is spaced away from the chassis 7. At that time, the left projection 26 of the cassette withdrawing lever 24 is pushed by the pin 30 of the slider 45, so that the cassette withdrawing lever 24 is rotated clockwise in Figure 9 to revolve the pivot 32 around the shaft 28, and thus, the disk cassette 1 is moved in a direction of arrow b ′ by the cassette withdrawing arm 33 which is driven by the pivot 32. After the slider 45 is returned to the position shown in Figure 1, the slider 45 passes the above position in a short distance due to contact of the pin 60 with the first straight portion 55 a of the cam face 55, and thereby, the cassette withdrawing lever 24, which is pushed by the pin 30 of the slider 45, passes the position shown in Figure 1 in a short distance, so that the free end of the projection 35 of the cassette withdrawing arm 33 is pushed against the stop 39 and the cassette withdrawing arm 33 is rotated in the direction of arrow e as indicated in two-dots-and-dash lines in Figure 9. Thus, the convex 36 of the cassette withdrawing arm 33 is disengaged from the recess 6 of the disk cassette 1. Thereafter, the disk cassette 1 is ejected by the shutter opening lever 19 which is urged by the torsion spring 20. The pin 30 of the slider 45 is engaged with the steplike notch 43 of the locking lever 40, because the eccentric pin 62 is disengaged from the cam face 55 of the inverse cam means 54, and returned to the position shown in Figure 1. In the meantime, when the convex 36 of the cassette withdrawing arm 33 is engaged with the recess 6 of the disk cassette 1 as shown in Figure 7, and thereafter, the cassette withdrawing arm 33 is withdrawn in the direction of arrow b , a contact force F is produced at a contact point of the rear side face 6 a of the recess 6 with the convex 36. If the tangent line 63 and the normal 64 are drawn at the contact point, the normal 64 coincides with the line of action of the contact force F , and if the pivot 32 of the cassette withdrawing arm 33 is not on a side, near to the center of the mechanism, of the normal 64, the convex 36 is easily disengaged from the recess 6, because a moment of the contact force F is exerted on the cassette withdrawing arm 33 counterclockwise in Figure 7. However, in this invention, the pivot 32 is on the side, near to the center of the mechanism, of the normal 64, so that the convex 36 is not disengaged from the recess 6 during the withdrawal by the cassette withdrawing arm 33. Moreover, in this invention, the stop 39 and the projection 35 of the cassette withdrawing arm 33 are provided besides, so that the disk cassette 1 can be drawn out from the mechanism even after the convex 36 is engaged with the recess 6, because the pivot 32 is moved in the direction of arrow b ′ when the disk cassette 1 is drawn by hand in the same direction, so that the cassette withdrawing lever 24 is rotated clockwise in Figure 7 against the force of the tension spring 29, and after the projection 35 of the cassette withdrawing arm 33 abuts against the stop 39, the cassette withdrawing arm 33 is rotated counterclockwise in Figure 7 against the force of the tension spring 37 to disengage the convex 36 of the cassette withdrawing arm 33 from the recess 6 of the disk cassette 1. It is noted that recess 6 has a pair of side faces 6 a and 6 b which form an angle of 15° with the central line thereof as shown in Figure 2.

Claims: A disk-cassette loading mechanism having cassette withdrawing means (33) to be engaged with an inserted disk cassette (1) and to withdraw it automatically into a predetermined position, wherein: the cassette withdrawing means (33) is so provided as to be rotatable on a pivot (32) which is provided in the driving means (24), biased urging means (37) is provided for rotatively urging the cassette withdrawing means (33) in a direction for engaging an engaging portion (36) of the cassette withdrawing means (33) with an engaged portion (6) of the disk cassette (1), the pivot (32) driven by the driving means (24) is moved in a direction for withdrawing the inserted disk cassette (1) so as to automatically withdraw the disk cassette (1) into the predetermined position after the engaging portion (36) of the cassette withdrawing means (33) is engaged with the engaged portion (6) of the disk cassette (1), and wherein disengaging means for disengaging the engaging portion (36) of the cassette withdrawing means (33) from the engaged portion (6) of the disk cassette (1) is provided comprising a stationary stopper (39) which abuts a part of the cassette withdrawing means such that the cassette withdrawing means (33) is rotatively moved against the biased force of the urging means (37) by a force exerted on the cassette withdrawing means (33) when the disk cassette (1) is drawn in opposition to the direction for withdrawing the inserted disk cassette (1). A disk cassette loading mechanism according to claim 1, wherein: the driving means (24) is so provided as to be rotatable on a shaft (28); second urging means (29) is provided for rotatively urging the driving means (24) to move the pivot (32) in the direction for withdrawing the disk cassette (1); locking means (40) is provided to lock the driving means (24) in a position from which the driving means (24) begins to withdraw the cassette withdrawing means (33); and when the driving means (24) is unlocked, the pivot (32), which is integral with the driving means (24), is moved in the direction for withdrawing the disk cassette due to force of the second urging means (29). A disk cassette loading mechanism according to claim 2, wherein the driving means (24) is unlocked due to a motion of the locking means (40), which is caused by a push given by the inserted disk cassette (1). A disk cassette loading mechanism according to claim 2 or 3, wherein shutter opening and shutting means (19) is provided to open a shutter (3), which is secured to the disk cassette (1), as the disk cassette (1) is inserted into the mechanism, and during ejection of the disk cassette (1), to shut the shutter (3) on the one hand and push out the disk cassette (1) on the other hand, and substantially at the same time when the engaged portion (6) of the disk cassette (1) is engaged with the engaging portion (36) of the cassette withdrawing means (33), the locking means (40) is moved by the shutter opening and shutting means (19) in a direction for unlocking the drive means (24). A disk cassette loading mechanism according to anyone of claims 1 to 4, wherein: a slider (45) is so provided as to be slidingly driven by the driving means (24) to be lowered from the upper position to the lower position thereof while the driving means (24) moves the pivot (32) in the direction for withdrawing the disk cassette (1), so that in the lower position, a recording disk (2) accommodated in the disk cassette (1) is mounted on a turntable (8) and simultaneously, faces a reader (9).

Inventors: SOGA RYO, SOGA, RYO
Applicants: SONY CORP, SONY CORPORATION
Application year: 1990
Main classification: G11B17
IPC codes: G11B17