Basf Aktiengesellschaft

Karl Uhl

Eberhard Koester

Paul Deigner

Roland Falk

Dieter Schaefer

Klaus Manzke

Klaus Schoettle

Herbert Motz

Heinrich Wittkamp

Richard Schneider

Peter Hammerschmitt

Werner Steck

Dieter Mayer

Gerd Wunsch

Hans-Joerg Hartmann

Roland Brotzler

Peter Felleisen

Lambert Kohl

Gerhard Rotter

Gerhard Berg

Heinrich Hartmann

August Lehner

Werner Balz

Joachim Hack

Herbert Spoor

Guenter Vaeth

Peter Dobler

Rudolf Bachmann

Helmut Lewin

Werner Stumpfi

Werner Senkpiel

Georg Huber

Robert Gertz

Dieter Graw

Winfried Gutermann

Peter Gawlik

A device for magnetically orienting the magnetizable particles of magnetic recording media in a preferred direction, which media are obtained by applying a coating of anisotropically magnetic particles finely dispersed in a solution of an organic binder system and conventional additives to a non-magnetic base, and subsequently solidifying the coating, by the action, on the still fluid coating, of the magnetic fields produced by two E-shaped electromagnets arranged symmetrically with respect to, and in mirror-image relationship to, the plane of the said coating.

Device for magnetically orienting the magnetizable particles or magnetic

A device for positioning magnetic heads over preselected tracks on magnetic disks in memory processing units, the device consisting essentially of a linear electric motor, including a stationary, partially hollow magnetic device, and of a support member and a guide member which is mounted on the latter in an axially movable manner and is provided with at least one head mount for at least one head support, wherein the support member is mounted at one end of the magnetic device and is otherwise unsupported by the chassis of the memory processing unit.

Device for positioning magnetic heads in memory processing units

A drive apparatus for a magnetic disc, particularly a flexible magnetic disc in an envelope, distinguished by a compact design which is achieved by so designing and arranging the linkage between the drive's closure member and disc clamping member that they take up as little room as possible. By designing the linkage in the form of a roller and lever arrangement and arranging them substantially on the central longitudinal axis of the housing of the drive apparatus in the upper portion of the housing, the maximum amount of space is available on either side of the linking means for printed circuit boards and electronic components. In a very advantageous embodiment, the closure member, linkage and clamping member and part of the housing are assembled as a single unit which is ready for fitting. The drive apparatus of the invention can be used for any kind of flexible or rigid magnetic disc.

Drive apparatus for magnetic discs

An automatic loading/unloading device for at least one magnetic head, consisting essentially of a support for the head and a spring-like member incorporating a ramp, the head support being decouplable from the spring-like member during loading and recouplable thereto upon unloading. The loading/unloading device of the invention can be used with advantage in any type of magnetic storage system which employs rigid magnetic media and magnetic heads which can be positioned relative to said magnetic media.

Device for the automatic loading/unloading of at least one magnetic head

The invention relates to an improved apparatus for the manufacture of magnetic discs carrying very thin magnetic layers, by applying a fluid dispersion of magnetic materials in a binder mixture to rigid base discs by the spin-coating process. Above the side of the base disc which is to be provided with the magnetic layer, there are arranged means which produce an aerodynamic boundary layer above the discs during rotation of the latter. This avoids the formation of surface irregularities and of coating streaks during production of the layer by spin-coating.

Apparatus for spin coating in the production of thin magnetic layers for

The cartridge arrangement of the present invention enables recording and/or playback apparatus to be used with cartridges of various sizes, the cartridges being provided with releasable locking means and, after the release of such means, being able to be opened to permit the tape roll(s) to be rotated on the recording and/or playback apparatus. The cartridge arrangement is applicable to every type of recording medium in tape or strip form in systems employing cartridges in which there is a need for using cartridges of various sizes, especially in the case of the recording and playback of magnetic signals.

Cartridge arrangement comprising an adapter

A positioning device for a write/read magnetic head in a magnetic disc data storage device comprising a motor-driven guide disc, with a spiral-shaped guide wall arranged at right angles to the plane of the guide disc, for a guide element in the form of a ball-bearing on a magnetic-head support. Due to the greatly reduced friction it is possible to achieve highly accurate positioning within an extremely brief period of time and with an extremely low power requirement. This device may be used to position the heads in magnetic disc systems for the recording and/or reproduction of analog or digital signals.

Positioning device for a write/read magnetic head in a magnetic-disc

A positioning device for objects of low mass, particularly magnetic heads in memory processing units having at least one pivotable head support and at least one pivotable support for at least one coil, which coil support is located in the air gap of a magnet assembly, the magnet assembly comprising pairs of flat permanent magnets whose air gaps are arranged next to each other and whose poles are so arranged that poles of unlike polarity are opposite each other, and the coil(s) being of elongate shape, the longitudinal conductors of which coil(s) are always located inside the said air gaps and the transverse conductors are always located outside said air gaps. The device of the invention can be used for all positioning operations requiring a very high degree of accuracy, in particular to position write/read devices of every kind and measuring and testing probes in control engineering and the laboratory.

Magnetic head pivotal support with compact drive means

The invention concerns a system for recording and/or reproducing data signals on a magnetic recording medium, more particularly a new improved transducer locating system. The magnetic transducer is provided with an air gap for the data track and a second air gap for the reference track which latter is formed on a recording medium as a transition line between regions of varying magnetization and arranged within, or laterally of, the data track. As the transducer deviates from its desired track position, a correction signal is produced which is fed to a locating device to which the transducer is fitted, in order to adjust the position of the transducer.

Track-dependent transducer position control in magneto-dynamic storage

The invention relates to an improved process for the manufacture of magnetic discs carrying very thin magnetic layers, by applying a fluid dispersion of magnetic materials in a binder mixture to rigid base discs by the spin-coating process. Above the side of the base disc which is to be provided with the magnetic layer, there are arranged means which produce an aerodynamic boundary layer above the discs during rotation of the latter. This avoids the formation of surface irregularities and of coating streaks during production of the layer by spin-coating.

Manufacture of magnetic discs

The invention is directed to a tape transport mechanism for recording and playing back video signals comprising a contact winding mechanism with tape-guiding means at the capstan and a magnetic tape in which the substrate is a polyethylene terephthalate film. The coated side of the tape, during transport, is in contact with the guide surface of the guide means, and no part of the transport mechanism at which slip could occur during the tape transport is allowed to be in contact with the tape substrate. The tape is wound with its substrate on the inside and its coated side is preferably abrasive with respect to the guide surface, which latter may advantageously consist either of steel or a ceramic material. The bonding agent of the magnetic dispersion -- preferably a chromium dioxide dispersion -- may be prepared from a polyurethane/polyvinyl chloride mixture which imparts the desired hardness to the tape. The arrangement can be advantageously employed with any kind of record/playback apparatus for video signals which includes a stationary head and develops high tape advance speeds.

Tape transport mechanism for recording and playing back video signals

A change-over mechanism for disk-shaped recording media, especially for magnetic films in a sleeve, is provided with a magazine and with selector, transport and drive mechanisms which can provide any desired access to any recording medium and permit trouble-free operation. The mechanism can be used for floppy disks and any type of film-like or rigid recording media.

Change-over mechanism for recording media, especially for floppy disks

A magazine for transport and operation in a device for a plurality of film-like flat recording media, especially of floppy disks. Details of the magazine according to the invention relate to a part which receives the recording medium, a lid, a mechanism for locking the said parts together, and a guide and gripper part.

Magazine for a plurality of recording media

The invention relates to magnetic recording media comprising a non-magnetic base and, applied thereto, a firmly adhering magnetic coating based on a finely divided magnetic pigment dispersed in a binder which contains at least 50 percent by weight of a special polyurethane elastomer. This polyurethane elastomer is a thermoplastic polyurethane which is soluble in tetrahydrofuran and free from isocyanate groups, and which has been manufactured from (A) 1 mole of one or more hydroxyl-containing polyesters and/or hydroxyl-containing polyethers of molecular weight from 600 to 4,000, (B) from 3.5 to 15 moles of a branched-chain aliphatic diol of 4 to 10 carbon atoms or a mixture of aliphatic diols of 2 to 10 carbon atoms, of which at least 50 mole percent is a branched-chain aliphatic diol of 4 to 10 carbon atoms, (C) from 0 to 1 mole, but not more than 15 mole percent of the aliphatic diols according to B, of an aliphatic polyol with from 3 to 6 OH groups and 3 to 18 carbon atoms, and (D) from 4.5 to 18 moles of a diisocyanate of 6 to 30 carbon atoms, the amount of NCO groups being approximately equivalent to the amount of OH groups of the sum of the components A to C. Magnetic recording media which contain such a polyurethane in the magnetic coating are distinguished by high surface hardness coupled with a markedly improved orientation ratio, a higher packing density and more uniform dispersion of the magnetic particles in the coating.

Magnetic recording media containing elastomeric polyurethane binders in

The invention relates to a process for the manufacture of improved magnetic discs by applying a thin layer of a liquid dispersion of magnetic pigments and optionally further, non-magnetic, pigments in a binder mixture to a non-magnetic rigid base, and curing the magnetic coating which has been applied. The binder used is a mixture of polycondensates comprising 60 to 70% by weight of a solid curable polycondensate of 2,2-bis(4-hydroxyphenyl)-propane and epichlorohydrin having an epoxy equivalent weight from about 400 to 2,500 and a melting point from about 50.degree. to 150.degree. C, 10 to 30% by weight of a curable allyloxybenzene-formaldehyde condensate of the resol type with free methylol groups or with methylol groups etherified with a lower alcohol, and having a molecular weight of less than 1,000, and 10 to 30% by weight of a curable melamine-formaldehyde condensate with more than two methylol groups etherified with n-butanol or iso-butanol, and having a molecular weight of less than 2,500. A magnetic dispersion using such a binder allows the application of a firmly adhering magnetic coating, even in thicknesses of less than 4 .mu., to aluminum discs or pre-coated aluminum discs, and the magnetic coating produced has high resistance to mechanical wear.

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Frankenthal, Germany

Karl Uhl