MAGNETIC DISK DRIVING DEVICE

Abstract: A magnetic disk driving device is adapted such that by closure of an outer cover, a magnetic disk is press-fitted on a spindle by a push of push members without producing any play and the rotating surface of the magnetic disk is fixed by a regulating member, and by clamping of the outer cover, which is effected when the outer cover has once reached the position closest to a base and then slightly retreated therefrom, the push members are separated from the magnetic disk by means of relative movements of the outer cover and a plate with the positional relationship between the magnetic disk and the regulating member kept as it is.

Description: The present invention relates to a magnetic recording and reproducing apparatus in which a magnetic head is shifted radially with reference to a magnetic disk contained in a hard case for making magnetic record and reproduction and more particularly to a magnetic disk driving device for driving the disk in the hard case to rotate. Hitherto, magnetic recording and reproducing apparatus has comprised a disk supporting member, called a diskette base or basket, for supporting a magnetic disk and an outer cover for covering the disk supporting member rotatably attached to a base having a spindle and a magnetic head thereon, said magnetic disk being adapted to be loaded onto the spindle when the disk supporting member and the outer cover are closed. Such a structure as described above is arranged such that, while the magnetic disk is driven by the spindle, the magnetic head is shifted radially with reference to the magnetic disk thereby to process data. In the above apparatus, there is included a push member for pushing the centre portion of the magnetic disk to the side of the spindle and a regulating member for pressing the magnetic disk to the magnetic head. The push member is required for the reason that the magnetic disk must be put on the spindle in a tight engagement therewith and the regulating member is required for the reason that reliable processing of data cannot be achieved if the condition of contact between the rotating surface and the magnetic head is unsteady. In addition, it is necessary that the regulating member and push member are detached from the magnetic disk when the outer cover and disk supporting member are rotated to their opening direction. Such a construction has suffered from a number of disadvantages, namely when the push member and the regulating member are fitted to different supporting members, when the outer cover is being opened, these supporting members must be interlinked therewith in separating the head from the magnetic disk. The adjustments of operating timing for various parts to have such an operation are difficult, and hence, pertinent structure and assembly work thereof are complex and a large number of parts were required. Furthermore French Patent Application 2 497 993 discloses a floppy disk driving device comprising a base, a disk supporting member hingedly attached to said base, a removable magnetic disk, a spindle, a magnetic head, an outer cover, a plate elastically attached to the interior of said cover, plate supports attached to the base for the purpose of fixing the plate distance and a regulating member attached to said plate for the purpose of fixing the rotating surface of the disk. And German Patent Application 3 415 412 discloses a disk recording and reproducing device comprising a clamp mechanism for an outer cover, in a position where the outer cover is slightly retreated from the position close to the base which has been reached by the outer cover. The outer cover pushes the central part of the disk against the spindle by elastic means. SUMMARY AND OBJECTS OF THE INVENTION The invention is set out in Claim 1. The present invention is characterised in that there is provided a clamp mechanism for clamping said outer cover, when the outer cover is moved to the side of said base, in a position whereto the outer cover has slightly retreated from the position closest to the base which has been reached by the outer cover; push members attached to said plate through a plate spring and facing the centre portion of said magnetic disk with a small distance kept therefrom when said plate has abutted on said plate supports; and a spring support attached to the interior of said outer cover for pushing said plate spring thereby to cause said push members to push the centre portion of said magnetic disk in snap action when the outer cover has made the maximum displacement in the direction of said base, and for causing said push members to retreat from said magnetic disk when said outer cover is clamped. The essential feature introduced by the invention is that the push members attached to the plate and spring support attached to the interior of the outer cover are not shown in the previously mentioned prior art in the French and German patent applications. These features have benefits in practice. Thus, in one aspect, the present invention seeks to obtain a magnetic disk driving structure to push the magnetic disk to the side of the spindle and to simultaneously fix the rotating surface of the magnetic disk such that said structure will be simply provided and its assembly work will be easily made. In another aspect of the invention, the magnetic disk driving device structure makes a push member push the centre portion of the magnetic disk to the side of the spindle and ensures that the push member separates from the magnetic disk in an easy manner and that assembly work of said structure will be easily made. Furthermore, the invention seeks to provide a magnetic disk driving device operation whereby the push member moves the magnetic disk to the side of the spindle and at the same time has the rotating surface of the magnetic disk control the separation of the push member from the magnetic disk. When the disk supporting member with a magnetic disk loaded therein and the outer cover are rotated toward the side of the base as far as the maximum limit, the plate is adapted to be supported by the plate supports, whereby the plate spring pushed by the spring support is bent so that the push members are caused to push the centre portion of the magnetic disk. Thus, the centre portion of the magnetic disk is certainly press-fitted on the spindle. Simultaneously, the rotating surface of the magnetic disk is fixed by the regulating member and when the outer cover is clamped by the clamp mechanism, the spring support slightly retreats from the plate spring with the positional relationship between the magnetic disk and the clamp kept as it is, and the push member is thereby separated from the magnetic disk. The movement of the push members to push the magnetic disk and, when the outer cover is clamped, to separate from the magnetic disk and that of the regulating member to fix the rotating surface of the magnetic disk are achieved only by means of relative motion between the outer cover and the single plate. Therefore, the structure for such movements can be simplified and hence the assembling work thereof can be made easier. Since the operation therefore is only to rotate the outer cover to the maximum limit and then allow the outer cover to be clamped, the operability is made better. Besides the number of parts can be reduced. DESCRIPTION OF A PREFERRED EMBODIMENT Following is a description by way of example only and with reference to the accompanying drawings of a device according to the present invention. In the drawings:- Figure 1 is a partially enlarged vertical cross-sectional front view of an embodiment of the present invention wherein interlocked operation of a magnetic disk to be connected to a spindle following the closing motion of the outer cover is shown. Figure 2 is a partially enlarged vertical cross-sectional front view of the same in another state. Figure 3 is a partially enlarged vertical cross-sectional front view of the same in still another state. Figure 4 is a side view showing operation of a clamp mechanism. Figure 5 is a side view showing the same in another state. Figure 6 is a side view showing the same in still another state. Figure 7 is a perspective view of the whole body; and Figure 8 is an exploded perspective view showing the state of fitting of a plate to an outer cover. A preferred embodiment of the present invention will be described below referring to the accompanying drawings, wherein 1 denotes a base and the same is provided thereon with a spindle 2a directly coupled with a spindle motor 2, and at a side of the base 1, there is provided a gear 3, directly coupled with a step motor (not shown), and a segment gear 4 in engagement with each other. A rack 6 in engagement with a gear 5 integrally rotating with the segment gear 4 is constituting a part of a carrier 8 travelling along a carrier shaft 7. A head mounting plate 9 attached to the carrier 8 through a connecting plate 8a is provided with an adjustment screw 10 rotatably, though prevented from axial movement, fitted thereon, the adjustment screw being arranged perpendicularly to the carrier shaft 7. The adjustment screw 10 is put in thread engagement with a head base 12 constituting a portion of a magnetic head 11. To the base 1 are rotatably fitted a disk supporting member 13 and an outer cover 14 through a support shaft 15. By the disk supporting member 13, a hard case 17 containing a magnetic disk 16 is removably supported. The magnetic disk 16 is provided with a flange 19 with a connecting hole 18 for connection with the spindle 2a made in the centre portion thereof. On the right side of the hard case 17, there is provided a shutter 20 for exposing a portion of the magnetic disk 16 operably attached to the right side periphery thereof for sliding along the same, and there is also provided a lock claw 21 for locking the movement of the shutter 20 operably attached to the same for displacement being urged outwardly. On the right side of the disk supporting member 13, there is provided an engagement portion (not shown) to cause the lock claw 21 to retreat inward when the hard case 17 is inserted thereby to open the shutter 20 and a wire 22 to be put in engagement with the shutter 20. On a plate 23 formed substantially in a triangular shape, there is provided fixed thereto a regulating member 24 opposing to the magnetic head 11 and there is also provided an index sensor 25 fixed thereto opposing to a magnetic member (not shown) formed in a minimum dot shape on the magnetic disk 16 slightly apart from the centre thereof and two push members 27 in the form of pins supported by a plate spring 26 and urged toward the side of the outer cover 14. The plate spring 26 is urged to separate from the plate 23 by its own spring force but is supported by a spring support 26a formed on the interior of the outer cover 14. In the plate 23, there are made two engagement holes 28, openings 28a, 29 and two positioning holes 30. On the outer cover 14, there are provided two bosses 31 slidably fitting in the engagement holes 28, a boss 32 opposing the hole 28a, and a window 33. Further on the interior of the outer cover 14, there are provided three bosses 34 one of which is to stick out from the hole 29 and the other two are to be disposed outside the outer edges of the plate 23, and these bosses 34 are provided with springs 35 pressed therein. The plate 23 is operably supported for displacement toward the side of the base 1 with its one side engaged with the window 33 and its engagement holes 28 inserted by screws 36, the screws 36 being threaded in the bosses 31. The plate 23 is urged toward the side of the base 1 by means of springs 37 as elastic members put on the periphery of the bosses 31. On the base 1, there are set up three plate supports 38 for supporting the plate 23, and on the top of the two of these plate supports 38, there are formed protrusions 39 to be put in engagement with the positioning holes 30 in the plate 23. On the base 1, there are also set up a pin 41 to be engaged with a hole 40 made in the hard case 17 and a pin 42 to support the bottom face of the hard case 17. A clamp shaft 51 disposed on the base 1 is provided at its right end fixed thereto with a clamp claw 43 and on the left end fixed thereto with a clamp claw 44 having a handle 44a. On both sides of the outer cover 14, there is provided integrally formed therewith protruded pieces 45 to engage with the clamp claws 43, 44. On the left-hand side of the base 1, there is operably provided a hook 46 for rotation around a shaft 47, which hook 46 is adapted to cause the clamp claw 44 to retreat from the protruded piece 45. There is stretched a spring 48 between the hook 46 and the clamp claw 44. On the left-hand side of the outer cover 14, there is formed a protruded piece 49 which is adapted to abut against the hook 46. Thus, a clamp mechanism 50 is made up of the clamp shaft 51, clamp claws 43, 44 and the hook 46. Within the above described arrangement, the clamp claw 44 is urged to the direction to cause locking by the spring 48. The support shaft 15 is provided around the same with a torsion spring (not shown) for urging the same to its opening direction. The disk supporting member 13 is provided with empty spaces at places so as not to interfere with such as the spindle 2a, magnetic head 11, regulating member 24, index sensor 25, push member 27 and springs 35. With the structure as described above, the shutter 20, in the process of insertion of the hard case 17 into the disk supporting member 13, is caused to slid backward by means of the engagement portion on the right of the disk supporting member 13, whereby a portion of the magnetic disk 16 is exposed to the magnetic head 11 and the regulating member 24. The closing operation of the outer cover 14 will be described. Figures 1 and 4 show the apparatus in the state where the outer cover 14 is opened. The plate 23 there is positioned at a large distance from the interior of the outer cover 14 by means of the pressure of the springs 37, and the plate spring 26 is raised up from the plate 23. Figures 2 and 5 show the apparatus in the state where the outer cover 14 have been rotated toward the side of the base 1 to the maximum limit, whereby the hook 46 is pushed by the protruded piece 49 and the clamp claw 44 is released from the hook 46. In the meantime, the plate 23 is supported by the plate supports 38 and the plate spring 26 is bent by being pushed by the spring support 26a, and thereby the push members 27 are caused to push the flange 19 of the magnetic disk 16. Thus the magnetic disk 16 is certainly press-fitted on the spindle 2a without producing any play. Figures 3 and 6 show the apparatus in the state where the outer cover 14 is released from the press of a hand. In this state, the outer cover 14 has been slightly retreated from the position closest to the base 1 by means of the pressure of the springs 37 and clamped by the clam claws 44, 43. By a slight retreat of the spring support 26a from the plate 23, the plate spring 26 is slightly raised from the plate 23 and the push members 27 are separated from the magnetic disk 16. Thereupon, the magnetic disk 16 is rotated driven by the spindle motor 2 through the spindle 2a and the magnetic head 11 is shifted radially with reference to the magnetic disk 16 being carried by the carrier 8 which is driven by driving force from rotation of the step motor transmitted through gears 3, 4 and 5 and the rack 6, and thus data are processed. At this time, since the centre portion of the magnetic disk 16 is certainly press-fitted on the spindle 2a, a correct truck search is ensured. Since the push members 27 have been retracted and the rotating surface of the magnetic disk 16 is kept from the hard case 17 by being regulated by the regulating member 24, the magnetic disk 16 is assured of making smooth rotation. When taking out the hard case 17, the handle 44a is pressed to rotate the clamp claws 43, 44. Thereby the outer cover 14 is rotated in its opening direction by means of the spring force of the torsion spring and, interlinked with this motion, the disk supporting member 13 is rotated in the direction to be released. In Figure 7, in order to indicate the internal arrangement, the angle of rotation of the outer cover 14 is illustrated wider than reality. In reality the same is as narrow as illustrated in Figure 4. According to the present embodiment, as described above, the operation to push the magnetic disk 16 by means of the push members 27 against the spindle 2a so that the same is press-fitted on the spindle 2a without producing any play and the operation to fix the rotating surface of the magnetic disk 16 by means of the regulating member 24 are performed by relative movement between the outer cover 14 and the single plate 23. Besides, since the outer cover 14 and the plate 23 are connected through springs 37, strict accuracy is not required in the positioning of both the members. Therefore, they can be arranged in simpler structure and assembled by simplified work. At the time of the clamping of the outer cover 14, the operation to separate the push members 27 from the magnetic disk 16 is also achieved by relative movement between the outer cover 14 and the plate 23 coupled with each other through the springs 37. Therefore, the structure to cause such operation is also made simpler leading likewise to simplified assembly work therefor. Furthermore, the operation to mount the magnetic disk 16 in place as described above is achieved by once rotating the outer cover 14 to the maximum limit and then allowing the outer cover 14 to be clamped, so that the operability therefor is made better. In addition, the number of required parts can be decreased and therefore both manufacturing cost and parts cost can be reduced.

Claims: A magnetic disk driving device comprising: a base (1); a disk supporting member (13) attached at one side thereof to said base through a shaft (7) operably for raising up from and laying down on said base; a magnetic disk (16) removably supported by said disk supporting member; a spindle (2a) supported by said base for driving said magnetic disk; a magnetic head (11) supported by said base for reciprocating in a radial direction of said magnetic disk; an outer cover (14) disposed outside the rotation of said disk supporting member and operably attached to said base for raising up from and laying down on said base through the same shaft and in the same position as the disk supporting member is attached; a plate (23) operably attached to the interior of said outer cover through elastic members (37) for replacement; plate supports (38) attached to said base, when said outer cover is moved in the direction of said base, for fixing opposition distance between said plate and said base; a regulating member (24) attached to said plate for fixing the rotating surface of said magnetic disk when said outer cover is clamped; characterised by a clamp mechanism (50) for clamping said outer cover, when the outer cover is moved to the side of said base, in a position whereto the outer cover has slightly retreated from the position closest to the base which has been reached by the outer cover; push members (27) attached to said plate through a plate spring and facing the centre portion of said magnetic disk with a small distance kept therefrom when said plate has abutted on said plate supports; and a spring support (26a) attached to the interior of said outer cover for pushing said plate spring thereby to cause said push members to push the centre portion of said magnetic disk in snap action when the outer cover has made the maximum displacement in the direction of said base, and for causing said push members to retreat from said magnetic disk when said outer cover is clamped. A magnetic disk driving device according to claim 1, wherein a protruded piece (49) is formed on said outer cover and a clamp claw (44) is rotatably attached to said base which is engaged with said protruded piece when the same is rotated in a predetermined direction, said clamp claw being adapted, when said outer cover is displaced to the maximum in the direction of said base, to be rotated in the direction to be disengaged from said protruded piece, and, when said outer cover, after being displaced to the maximum in the direction of said base, is slightly retreated from said base, to be rotated in the direction to be engaged with said protruded piece. A magnetic disk driving device as claimed in claim 1 or claim 2 wherein said elastic members between said outer cover and plate are formed of springs. A magnetic disk driving device as claimed in any preceding claim, wherein said push members are formed in such shapes that the same cause the spindle to fit in the centre portion of said magnetic disk and push portions on said magnetic disk disposed opposite to each other with said spindle between. A magnetic disk driving device as claimed in any preceding claim wherein said outer cover is always urged in the direction to be opened away from said base.

Inventors: AOKI, CHIHIRO, KAWAHIRA, MASAYOSHI, MURAKAMI, KEISUKE
Applicants: TOKYO ELECTRIC CO., LTD.
Application year: 1986
Main classification: G11B17
IPC codes: G11B17