Head load/unload mechanism for rotating magnetic memories

#This invention relates to head load/unload mechanisms for rotating magnetic memories and, more particularly, to solenoid controlled head load/unload mechanisms for loading and unloading the read/write head or heads of single or double sided floppy disk drives into and out of data transfering relationship with a magnetic recording medium.

#Floppy disk drives customarily employ a recording medium comprising a thin, pliant, disk-shaped substrate which has a magnetic oxide surface coating. Such a recording medium is conventionally encased within a protective outer jacket, but there normally are radially extending access slots which pass through the opposing faces of the jacket so that the read/write head or heads of a drive can be compliantly loaded directly against the recording medium to transfer data thereto or therefrom. In operation, the recording medium is inserted into a drive where it is clamped on a spindle for rotation at a substantially constant rate within its protective jacket. The head or heads of the drive are aligned with the access slots in the jacket and are mounted for movement radially of the recording medium so that any selected one of a plurality of concentric data tracks may be accessed. As will be appreciated, a double sided drive provides access to the data tracks on either side of the recording medium, while a single sided drive only has access to the data tracks on one side of the recording medium.

#To avoid excessive head/media wear, most single and double sided floppy disk drives have a solenoid controlled head load/unload mechanism for selectively "loading" and "unloading" the read/write head or heads depending on whether the drive is operating in an active data transferring mode or not. When the drive is selected for a data transfer with, say, a host computer, the heads are "loaded" against the recording medium. Otherwise, however, the head or heads are displaced or "unloaded" from the recording medium to prevent any significant head/media wear from occurring, even if the drive is operated for extended periods of time in a standby mode.

#Still further objects and advantages of this invention will become apparent when the following detailed description is read in conjunction with the attached drawings, in which:

#FIG. 1 is a cut-away perspective view of a double sided floppy disk drive having a head load/unload mechanism constructed in accordance with the present invention;

#FIG. 2 is an enlarged perspective view of the head load/unload mechanism;

#While the invention is described in detail hereinbelow with reference to a particular embodiment, it is to be understood that there is no intent to limit it to that embodiment. On the contrary, the intent is to cover all modifications, alternatives and equivalents which fall within the spirit and scope of the invention as defined by the appended claims.

#Turning now to the drawings, and at this point especially to FIG. 1, there is a double sided floppy disk drive 11 having a solonoid controlled head load/unload mechanism 12 for selectively loading and unloading a pair of read/write heads 13 and 14 (see FIGS. 5-7) into and out of data transferring relationship with the opposite sides of a magnetic recording medium 15. As previously mentioned, the recording medium 15 typically comprises a thin, pliant substrate which is coated with a magnetic oxide. Accordingly, the recording medium 15 is housed within a protective outer jacket 16 which is slidably supported by card guides 17 and 18 so that the jacket protected recording medium 15 may be easily and safely inserted into and removed from the drive 11. The card guides 17 and 18 are secured to the base frame 19 of the drive 11.

#In operation, the recording medium 15 is clamped on a spindle 21 (by means not shown) for rotation within its protective jacket 16. A carriage 22, which has an upper arm 23 for supporting the upper or side-1 read/write head 13 and a lower arm 24 for supporting the lower or side-0 head 14, is mounted on a guide rail 25 for movement radially relative to the recording medium 15. Radially extending access slots 26 (only one can be seen) are cut through the opposite faces of the protective jacket 16 and are aligned with the read/write heads 13 and 14. Furthermore, there is an actuator 27 (such as the band drive disclosed in U.S. Pat. No. 4,161,004, which issued July 10, 1979 for a "Head Positioning Mechanism for Recording/Playback Machine") which is coupled to the carriage 22 for precisely controlling the positioning of the heads 13 and 14 radially relative to the recording medium 15. Consequently, data may be selectively transferred to or from any one of a plurality of concentric data tracks on either side of the recording medium 15.