Flexible magnetic disk recording apparatus

Claim 1

An apparatus for recording and/or reproducing binary information on a flexible magnetic disk having a magnetizable surface carrying a spiral track whereon said information is storable, said apparatus comprising: a rotating drive hub cooperative with said disk for rotation therewith, a plate connected to said hub for rotation therewith, said plate having a first surface carrying a first spiral guide associated with said spiral track and a second surface, opposite to said first surface, carrying a second spiral guide, a magnetic head assembly for recording and/or reproducing said information on said disk, said head assembly comprising first and second spaced arms between which said plate is located, a first element carried by said first arm, said first element normally in engagement with said first spiral guide to move said head from the periphery towards the center of said disk synchronously with the rotation thereof to follow the spiral track of said disk during the rotation of said plate, and a second element carried by said second arm and engageable with said second spiral guide for returning said head towards the periphery of said disk during the rotation of said plate, and means for alternately bringing said first element or said second element respectively into contact with said first spiral guide or with said second spiral guide.

Claim 2

An apparatus for recording and/or reproducing binary information on a flexible magnetic disk having a magnetizable surface carrying a spiral track whereon said information is storable, said apparatus comprising: a rotating drive hub cooperative with said disk for rotation therewith, a plate connected to said hub for rotation therewith, said plate having a first surface carrying a first spiral guide associated with said spiral track and a second surface, opposite to said first surface, carrying a second spiral guide, a magnetic head assembly for recording and/or reproducing said information on said disk, said head assembly comprising first and second spaced arms between which said plate is located, a first element carried by said first arm, said first element normally in engagement with said first spiral guide to move said head from the periphery towards the center of said disk synchronously with the rotation thereof to follow the spiral track of said disk during the rotation of said plate, and a second element carried by said second arm and engageable with said second spiral guide for returning said head towards the periphery of said disk during the rotation of said plate, and means for alternately bringing said first element or said second element respectively into contact with said first spiral guide or with said second spiral guide.

Claim 5

An apparatus for writing and/or reading binary information along a spiral path on a flexible magnetic disk, comprising: a direct-current electric motor for rotating said disk, a writing and/or reading head moving in operation, radially with respect to said disk from the periphery towards the center thereof, in synchronism with the rotation of said disk, first voltage generating means for continuously supplying said direct-current electric motor with a first voltage having a predetermined substantially constant threshold, start means for generating a start pulse responsive to the positioning of said head at the beginning of said spiral path, and second voltage generating means actuatable by said start pulse for supplying said direct-current electric motor also with a second voltage increasing as a function of time such that the angular speed of said disk increases during radial movement of said head from the periphery towards the center of said disk to maintain the relative speed between the spiral path of said disk and said head close to a nominal value whereby said information is written and/or read with a substantially constant density independent of the instantaneous radial position of said head.

Claim 6

An apparatus for writing and/or reading binary information along a spiral path on a flexible magnetic disk, comprising: a direct-current electric motor for rotating said disk, a writing and/or reading head moving in operation, radially with respect to said disk from the periphery towards the center thereof, in synchronism with the rotation of said disk, first voltage generating means for continuously supplying said direct-current electric motor with a first voltage having a predetermined substantially constant threshold, start means for generating a start pulse responsive to the positioning of said head at the beginning of said spiral path, and second voltage generating means actuatable by said start pulse for supplying said direct-current electric motor also with a second voltage increasing as a function of time such that the angular speed of said disk increases during radial movement of said head from the periphery towards the center of said disk to maintain the relative speed between the spiral path of said disk and said head close to a nominal value whereby said information is written and/or read with a substantially constant density independent of the instantaneous radial position of said head.

Claim 8

An apparatus for writing and/or reading binary information along a spiral path of a magnetic disk, comprising: electric motor means for rotating said disk, a writing and/or reading head moving radially with respect to said disk in synchronism with the rotation thereof, first supply means for continuously supplying said electric motor means with a first substantially constant voltage, start means for generating a start pulse responsive to the positioning of said head at the beginning of said spiral path, and second supply means actuatable by said start pulse for supplying said electric motor means also with a second variable voltage to increase the angular speed of the said disk during the radial movement of said head to write and/or read said information with a substantially constant density along said spiral path from the periphery to the center of the disk.

Claim 9

An apparatus for writing and/or reading binary information along a spiral path of a magnetic disk, comprising: electric motor means for rotating said disk, a writing and/or reading head moving radially with respect to said disk in synchronism with the rotation thereof, first supply means for continuously supplying said electric motor means with a first substantially constant voltage, start means for generating a start pulse responsive to the positioning of said head at the beginning of said spiral path, and second supply means actuatable by said start pulse for supplying said electric motor means also with a second variable voltage to increase the angular speed of the said disk during the radial movement of said head to write and/or read said information with a substantially constant density along said spiral path from the periphery to the center of the disk.

Claim 10

An apparatus for writing and/or reading binary information on a disk of the type having a central hole, a radial notch and a magnetizable surface defining a spiral track whereon said information is storable, said apparatus comprising: a rotating drive member, a magnetic head for writing and/or reading said information on said disk, means for moving said head radially with respect to said drive member in synchronism with the rotation of said member to follow the spiral track of said disk, an engaging member axially shiftable with respect to the hole of a disk positioned on said drive member with its central hole centered with respect to said drive member, and resilient means causing said engaging member to engage on the fly the notch of said positioned disk during rotation of said drive member to position said head automatically with respect to said spiral track.

Claim 11

An apparatus for writing and/or reading binary information on a disk of the type having a central hole, a radial notch and a magnetizable surface defining a spiral track whereon said information is storable, said apparatus comprising: a rotating drive member, a magnetic head for writing and/or reading said information on said disk, means for moving said head radially with respect to said drive member in synchronism with the rotation of said member to follow the spiral track of said disk, an engaging member axially shiftable with respect to the hole of a disk positioned on said drive member with its central hole centered with respect to said drive member, and resilient means causing said engaging member to engage on the fly the notch of said positioned disk during rotation of said drive member to position said head automatically with respect to said spiral track.

Claim 15

An apparatus for writing and/or reading binary information on a flexible magnetic disk having a central hole and a radial notch adjacent to said hole which together define a single opening in said disk, and a magnetizable surface carrying a spiral track whereon said information is storable, said apparatus comprising: a rotary drive hub, a transducer head assembly for writing and/or reading said information, means for radially moving said head assembly with respect to said hub, means synchronizing the radial movement of said head assembly with the rotation of said hub, means for supporting said disk between an inoperative position away from said hub enabling the insertion of said disk and an operative position positioning the central hole of said disk to couple said hub, and engaging means carried by said hub engageable with the radial notch of said disk for rotation thereof, said engaging means comprising a radial dog, guide means for rotating said radial dog bodily with said hub and for guiding said dog along an axis parallel to the axis of said hub, and elastic means for pushing said radial dog towards the operative position of said disk, so that said disk pushes said dog against the action of said elastic means to be engaged on the fly by said radial dog during the first rotations of said hub and then to be rotated therewith, when said supporting means positions the disk into the operative position thereof.

Claim 16

An apparatus for writing and/or reading binary information on a flexible magnetic disk having a central hole and a radial notch adjacent to said hole which together define a single opening in said disk, and a magnetizable surface carrying a spiral track whereon said information is storable, said apparatus comprising: a rotary drive hub, a transducer head assembly for writing and/or reading said information, means for radially moving said head assembly with respect to said hub, means synchronizing the radial movement of said head assembly with the rotation of said hub, means for supporting said disk between an inoperative position away from said hub enabling the insertion of said disk and an operative position positioning the central hole of said disk to couple said hub, and engaging means carried by said hub engageable with the radial notch of said disk for rotation thereof, said engaging means comprising a radial dog, guide means for rotating said radial dog bodily with said hub and for guiding said dog along an axis parallel to the axis of said hub, and elastic means for pushing said radial dog towards the operative position of said disk, so that said disk pushes said dog against the action of said elastic means to be engaged on the fly by said radial dog during the first rotations of said hub and then to be rotated therewith, when said supporting means positions the disk into the operative position thereof.