Abstract:
A lifting mechanism for a floppy disc device and including a base, a carrier pivotally mounted to the base, a collet arm pivotally mounted to the carrier and having an end biased in a clockwise direction, a collet attached to the collet arm, a pad arm having an end biased in a counterclockwise direction and a pad, the pad arm engaging under pressure the collet arm, a head carriage pivotally receiving the pad arm, and components for vertically moving the collect arm engaging the pad arm in synchronism with vertical movement of the carrier.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to a floppy disc device, and more particularly to a pad lifting mechanism which serves to maintain contact between a magnetic disc and a magnetic head, and aims to provide a pad lifting mechanism of simple structure which detachably attaches a magnetic disc housed in a case to the device. 
     Recently, magnetic memory devices have been rapidly developed in the field belonging to information machinery such as personal computers, word processers and others, and so-called floppy disc devices have been remarkable, and make use of flexible magnetic disc as a magnetic recording medium. 
     The floppy disc is inserted therein with a sheet like flexible magnetic disc supported in a jacket or a case such as hard case. The magnetic disc is held at its center under a predetermined pressure by means of a drive hub and a collet, and rotates it at a high speed by a drive motor connected to the drive hub. The device presses under the predetermined pressure the magnetic head at an exposed portion of the magnetic disc by means of the pad so as to move it in the radial direction of the disc for carrying out the record and reproduction. 
     Since each of the magnetic disc, the magnetic head and the case is effected with pressing force, they would be scratched when the case is attached to the device. Especially when the hard case is used such occasions would be remarkable. For avoiding them, the pressing force should be removed when the case is detached or attached. 
     SUMMARY OF THE INVENTION 
     For removing the pressure, the floppy disc device is provided with a mechanism which lifts the collet and the pad. The existing device utilizes a solenoid as such a mechanism, or employs a mechanism which separately lifts the collet and the pad. These mechanisms are rather complicated in structure. 
     In view of the above mentioned circumstances, the present invention has been realized to develop a pad lifting mechanism which is simple and smoothly detachably attached to the magnetic disc. That is, the invention is to provide a pad lifting mechanism comprising a carrier which is pivoted to a base of the device with its one end and is attached with a magnetic disc housed in a case, a collet arm which is pivoted on an upper surface of the carrier with its one end under biasing force in the clockwise direction and is attached with a collet at its center and lower side, a pad arm which is pivoted to a head carriage with its one end under biasing force in the counterclockwise direction and engages under pressure the end portion of the collet arm at its engaging end and is provided with a pad on its front end, and a means which vertically moves the collet arm engaging the pad arm in synchronism with vertical movement of the carrier. It is therefore an object of the present invention to maintain the collet and the pad in a position completely out of the guide path of the disc carriage when the disc carriage is in the released position. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a plan view of a floppy disc device according to the present invention; 
     FIG. 2 is a side cross sectional view showing the condition of record and reproduction of the device of FIG. 1; and 
     FIG. 3 is a view of the preparation of the record and reproduction condition of the device of FIG. 1. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An explanation will be made to an outline of the present device in reference to the attached drawings. A base 1 is fixed with an attaching plate 2, and the plate 2 is pivoted with a carrier 3 thereon. The carrier 3 is attached with a cassette disc 4, and a hard case 5 of the disc 4 is housed therein with a flexible magnetic disc 6. 
     The carrier 3 is provided at its end part with a hook 9. When the carrier 3 is pushed down, the hook 9 is caught by a catching portion 8a of a release button 8, and the condition of record and reproduction is achieved. On the other hand, when the release button 8 is pushed, the engagement is released and the carrier 3 is moved upward by the action of a spring 10, and the preparation for the record and reproduction is achieved. Under this condition, the cassette 4 is detachably attached to the carrier 3. The carrier 3 is formed with a bending portion 3a for contacting the case 5 when the cassette disc 4 is attached. 
     The carrier 3 is implanted thereon with bearings 11, 11a in parallel. The bearings 11, 11a are formed with holes into which a twist spring 13 is inserted. The twist spring 13 is coiled on a collet arm shaft 12, so that a collet arm 14 pivoting on the carrier 3 is biased in a clockwise direction. 
     The collect arm 14 is formed with a hole at its center part, and a collet attaching arm 17 is inserted therein. The arm 14 is mounted with a stopper ring 18 at its upper projection with respect to the collet arm 14, and at its lower projection with a collet 15 via a spring 16. 
     A head carriage 19 is implanted with bearings 21, 21a. A twist spring 22 is inserted into bearing holes formed in the bearings 21, 21a. Spring 22 is coiled on a pad arm shaft 23 so that a pad arm 24 is biased in the counterclockwise direction. 
     The pad arm 24 has a pad 25 at its end portion and lateral projections 26, 26a at its both sides. Due to the projections 26, 26a, the pad arm 24 is engaged under pressure with forked end portions 14, 14a of the collet arm 14. 
     The head carriage 19 has a magntic head 27 and is pivoted with the pad arm 24. The head carriage 19 is moved forward by the rotation of a step motor 28 along guide shafts 20, 20a by means of a drive mechanism, and slides in the radial direction of the magnetic disc 6 for performing the recording and reproduction of data. The above drive mechanism comprises a lead screw 29 fixed on a motor shaft of the step motor 28 and a follower 30 whose front end portion is inserted in a groove of the lead screw 29 and whose rear end portion is inserted in the head carriage 19. 
     The magnetic disc 6 is supported by the collet 15 and a spindle hub 32 whose spindle shaft 31 is secured on its upper portion with a center disc hub 7. The disc 6 is rotated at the high speed of the spindle shaft 31 by a drive motor 33. The disc 6 is pressed by the magnetic head 27 and the pad 25 while its record and reproduction part is in contact with its exposed portion, with the magnetic head 27 and the pad 25. 
     The lift lever 34 which is shaped is inserted with its end portion that is bent at a right angle into holes provided in both bent sides of the collet arm 14. The lift lever 34 has its center part in contact with the bending part 3a of the carrier 3 and has its rear part inserted into a square hole in a pulse motor attaching plate 35. 
     The floppy disc device of the present invention is composed as having stated above, and actuation thereof will be discussed in FIG. 2 with respect to record and reproduction. When the cassette disc 4 is attached to the carrier 3 and the latter 3 is pushed down, the hook 9 of the carrier 3 is engaged with the engaging portion 8a of the release bottom 8, and the disc hub 7 at the center of the flexible magnetic disc 6 is pushed by the collet 15 and engages the spindle 31. The flexible magnetic disc 6 contacts the magnetic head 27 at the exposed portion under pressure due to the pad 25. 
     When an order for the record and reproduction is given under the groove mentioned condition, the flexible magnetic disc 6 is rotated at high speed by the rotation of the spindle 31. The magnetic head 27 secured to the head carriage 19 contacts the flexible magnetic disc 6 and by the driving of the head carriage 19, by means of the step motor 28, moves it in its radial direction, and thereby making the recording and reproduction. 
     A further reference will be made to the preparing condition of the record and reproduction in FIG. 3. When the release button 8 is pushed at the completion of the record and reproduction, the hook 9 of the carrier 3 is released from the engaging portion 8a of the release button 8, and the carrier 3 is lifted upward along the guide path direction arrow 36 of the disc carriage 3 shown in FIG. 2, indicating the direction of the path in which the disc carriage 3 must travel in order to reach the released position depicted in FIG. 3 from the set position of FIG. 2. At this time, since the straight portion of the lift lever 34 contacts the bent part of the carrier 3 at its center part, the center part is also moved upward with the upward movement of the carrier 3. The lift lever 34 is restrained with respect to upward movement by having its rear end engaged with the pulse motor attaching plate 35 and being rotated in the clockwise direction around the fulcrum of the engaging portion of this rear end. 
     Since the lift lever 34 is engaged with the collet arm 14 at its end portion, the collet arm 14 is lifted upward with the movement of the lift lever 34 as mentioned above. At the same time, the pad arm 24 is also lifted upward, and the collet 15 attached to the collet arm 14 as well as the pad 25 attached to the pad arm 24 are lifted upward as shown in FIG. 3. 
     Attaching of the cassette disc 4 to the carrier 3 may be smoothly made without making scratches on the flexible magnetic disc 6, the magnetic head 27 or the hard case 5. 
     As having mentioned above, this invention is to provide a simple mechanical means which engages the collet arm for attaching the collet with the pad arm attached with the pad, and vertically moves the collet arm in accompany with vertical movement of the carrier for attaching the cassette disc. Thereby attaching of the cassette disc to the carrier may be smoothly made without making scratches on the flexible magnetic disc, the magnetic head or the hard case.