Magnetic disc apparatus

Claim 2

A random access disc memory system comprising: a plurality of interchangeable disc modules, each said module being characterized by an enclosing means enclosing: at least one magnetic disc rotatably mounted, at least one magnetic head associated with each side of each of said discs, an arm for carrying at least one of said magnetic heads, mounting means for supporting said arm for planar angular movement about a fixed axis where said fixed axis is at the center of gravity of said arm, and a motor connected to said arm, said motor dedicated solely for simultaneously selectively positioning one or more of said magnetic heads to any one of a plurality of concentric tracks located on said rotatable magnetic discs, said motor comprising a hollow coil carried by said arm and located So as to perform a translation movement along a curved path causing said arm to perform angular movement and a stator having magnetic pole pieces defining a magnetic flux gap therebetween and with said coil performs said translation movement, at least one of said pole pieces extending within the coil and at least one of said pole pieces extending outside the coil, so as that when current passes through said coil, magnetic flux crossing said gap will link said coil causing said coil to experience a force which causes said coil to perform said translational movement and move said arm angularly; a housing unit for accepting any one of said disc modules, said housing unit comprising; a first means mechanically connectable to said disc module for transmitting mechanical energy into said module only for rotating said discs within said module; and a second means electrically connectable to said disc module for controlling the operation of said motor with said module and for controlling the reading and writing of information on said discs by means of said heads.

Claim 3

A random access disc memory system as set forth in claim 1 wherein said disc, said arm with said head, and said electromagnetic actuator are contained together in said hollow enclosing means, the enclosing means having, and being designed to maintain, a substantially particle-free atmosphere therein constantly throughout the operational life of said enclosing means and its contents considered as a unit, during which time said disc, said arm with said head, and electromagnetic actuator remain continuously in said atmosphere in said enclosing means, said disc having coupling means associated therewith whereby the disc can be driven to rotate from the exterior of said enclosing means and said head and said electromagnetic actuator being operatively associated with signal communication means whereby head signals and actuator signals can be communicated between the exterior and interior of said enclosing means.

Claim 4

A random access disc memory system as set forth in claim 2 in which said disc is rotatably mounted via a spindle supported by bearing means carried by said enclosing means, said spindle extending to the exterior of said enclosing means.

Claim 5

A random access disc memory system as set forth in claim 3 wherein said arm during operation has, substantially no resultant aerodynamic force arising due to air being swept off said disc because of said disc rotation for causing said arm to tend to move said arm angularly.

Claim 6

A random access disc memory system as set forth in claim 4 wherein said discs are unidirectional driven, the positioning apparatus being so arranged that said arm, in the direction from the electromagnetic actuator to the head, extends generally opposite to the direction of motion of said discs past the heads.

Claim 7

A random access disc memory system as set forth in claim 5 wherein said discs are driven to rotate by a pulley and belt drive.

Claim 8

A random access disc memory system as set forth in claim 5 wherein said discs are driven to rotate by a clutch coupling between two clutch elements one of which is resiliently displaceable to allow non-coaxial driving engagement between the clutch elements.

Claim 9

A random access disc memory system as set forth in claim 2 wherein, said enclosing means being mounted on a sub-frame, which in turn is mounted on said housing such that removal of said enclosing means from said housing requires the sub-frame and enclosing means first to be removed as a unit from said housing.

Claim 10

A random access disc memory system as set forth in claim 8 wherein said second means includes actuator signal generating means connected to deliver said actuator signals via said signal communication means to said electromagnetic actuator, and head signal circuitry connected to deliver and/or receive said head signals via said signal communication means to and/or from said head.

Claim 11

A random access disc memory system as set forth in claim 2 further including sErvo-control means, for controlling movement of said arm so that said heads follow any addressed one of a plurality of concentric tracks on said discs, said servo-control means including within each said disc module servo-tracks recorded on one of said disc and an electromagnetic servo-track sensing head carried by said arm.

Claim 12

An interchangeable disc module as set forth in claim 1 wherein said arm has a section which is further from where said arm is mounted for said angular movement than said coil, causing said section to be moved a greater distance than said coil when said coil performs a translational movement within said gap of said motor.

Claim 13

An interchangeable disc module as set forth in claim 11 wherein said section of said arm carries said magnetic transducers to be positioned.

Claim 14

An interchangeable disc module as set forth in claim 12 wherein said coil of said motor is at the opposite end of said arm than said magnetic transducers, said arm being mounted for said angular movement intermediately between said magnetic transducers and said coil of said motor.

Claim 15

An interchangeable disc module as set forth in claim 1 wherein said pole pieces are constructed of permanent magnets.

Claim 16

An interchangeable disc module as set forth in claim 14 wherein the data of said motor is said ''''E''''-shaped, the three ends of said arms of the ''''E'''' being said pole pieces, said central arm of said ''''E'''' extending inside said coil and said two outer arms extending outside said coil.

Claim 17

An interchangeable disc module as set forth in claim 15 wherein said pole pieces have flat pole faces which face towards each other and said coil has a rectangular former, said former having two opposite sides of which extend parallel to said flat pole faces.

Claim 18

An interchangeable disc module as set forth in claim 16 wherein the winding density of said coil is concentrated towards the outer axial ends thereof causing the characteristic of said force against current passing through said coil for different angular positions of said arm to be substantially linear.

Claim 19

An interchangeable disc module for use with any one of a plurality of like disc drives, said module having a first set of interfaces adapted to coact with a second set of interfaces on each of said drives, said module comprising in combination; a base casting; a cover connecting to said casting to form a hollow enclosing means; a spindle assembly mounted in said base casting and having a first portion extending into said enclosing means and a second portion extending out of said enclosing means, said second portion being the first mechanical interface of said first set of interfaces; at least one magnetic disc mounted on said first portion of said spindle for rotation with said spindle; transducing means including at least one magnetic transducer located within said enclosing means; a motor within said enclosing means connected to said transducing means solely for selectively positioning said transducers to different concentric tracks of said magnetic disc; a first means connected to said transducer for controlling the transducing operations of said transducer, said first means including a portion, physically accessible outside said enclosing means, for carrying electrical signals, said portion being a first electrical interface of said first set of interfaces; a second means connected to said motor for controlling the operation of said motor, said second means including a portion, physically accessible outside said enclosing means for carrying electrical signals, said portion being the second electrical interface of said first set of interfaces; said first mechanical and said first and said second electrical interfaces of said first set of interfaces being in a constant fixed space relationship to each other and located in the same position in all disc modules of this type, so that disc modules will be interchangeable among a plurality of like disc driVes allowing data recorded on one disc module when coacting with a first one of said disc drives to be effectively read when said data module is coacting with the same or any second one of said disc drives.

Claim 20

An interchangeable disc module for use with any one of a plurality of like disc drives, said module having a first set of interfaces adapted to coact with a second set of interfaces on each of said drives, said module comprising in combination; a base casting; a cover connecting to said casting to form a hollow enclosing means; a spindle assembly mounted in said base casting and having a first portion extending into said enclosing means and a second portion extending out of said enclosing means, said second portion being the first mechanical interface of said first set of interfaces; at least one magnetic disc mounted on said first portion of said spindle for rotation with said spindle; transducing means including at least one magnetic transducer located within said enclosing means; a motor within said enclosing means connected to said transducing means solely for selectively positioning said transducers to different concentric tracks of said magnetic disc; a first means connected to said transducer for controlling the transducing operations of said transducer, said first means including a portion, physically accessible outside said enclosing means, for carrying electrical signals, said portion being a first electrical interface of said first set of interfaces; a second means connected to said motor for controlling the operation of said motor, said second means including a portion, physically accessible outside said enclosing means for carrying electrical signals, said portion being the second electrical interface of said first set of interfaces; said first mechanical and said first and said second electrical interfaces of said first set of interfaces being in a constant fixed space relationship to each other and located in the same position in all disc modules of this type, so that disc modules will be interchangeable among a plurality of like disc driVes allowing data recorded on one disc module when coacting with a first one of said disc drives to be effectively read when said data module is coacting with the same or any second one of said disc drives.