Abstract: A right parallelepiped cassette is provided with a guide insert as a separate housing part which can be produced and machined separately and very precisely, contains important guide elements of the cassette and can be oriented in a predetermined manner on reference surfaces of the remainder of the cassette housing and fastened thereon. In a particular embodiment, the cassette contains detachably fastened spacing elements for measuring the alignment of the guide elements. The cassette can advantageously be used for any type of recording media in tape or strip form.

Abstract: A right parallelepiped cassette is provided with a guide insert as a separate housing part which can be produced and machined separately and very precisely, contains important guide elements of the cassette and can be oriented in a predetermined manner on reference surfaces of the remainder of the cassette housing and fastened thereon. In a particular embodiment, the cassette contains detachably fastened spacing elements for measuring the alignment of the guide elements. The cassette can advantageously be used for any type of recording media in tape or strip form.

Abstract: An adjusting means for tape guide elements or magnetic heads effects adjustment exclusively in a plane at right angles to a reference surface. A fine adjustment mechanism, in particular a micrometer screw device, provides high accuracy of adjustment over a sufficiently wide range. The adjusting means can be used in any kind of magnetic tape cassette. Advantageous embodiments of such magnetic tape cassettes also form part of the present invention. By using the novel adjusting means, azimuth and skew losses can be compensated for in a simple manner.

Abstract: A tape cassette comprising at least one print-through echo-erasing device in the form of at least one appropriately shaped magnetic member made of permanent magnet material which is conveniently arranged on a tape guide element or near the apertures in the front wall of the cassette housing for the admission of scanning means. Such echo-erasing device can be used with advantage in any kind of magnetic tape cassette or cassette containing a recording medium having at least one magnetic track.

Abstract: In a tape cassette possessing symmetrically arranged support liners, a compressive force dependent on the tape roll diameter is exerted by the liner and utilized for centering the roll and the tape. Force/diameter relationships, and embodiments of folded liners for achieving individual forces are described. A novel dynamic liner arrangement can be used in any tape cassette possessing high winding speeds and sensitive tapes, with frequently alternating rewind/playback operation.

Abstract: A tape cassette is provided with interlocking wall sections to protect it against mechanical and/or thermal deformation. Advantageous interlocking connecting means are stepped teeth, peg-and-hole connections and connections in the form of prism-shaped projections and matching recesses.Such interlocking connecting systems can be used with particular advantage in film, audio, video and data cassettes and all kinds of storage containers which are required to exhibit great flexural strength.

Abstract: The invention relates to a hub for magnetic tape cassettes, especially compact cassettes, and to magnetic tape cassettes possessing such hubs. In a first embodiment, spring means are provided on the inner periphery of the hub and exert radial pressures on the drive spindle, the spring means consisting, for example, of sprung teeth. In a further embodiment, the teeth have a spring rate of from about 1 P/mm to 40 P/mm. In another embodiment, the hub consists of an inner part and an outer part which can be coupled to one another and between which there is some play after coupling. A large number of specific examples of hubs are given to show possible shapes and arrangements of the teeth, and to show the types of material that can be used. In an advantageous embodiment, the inner part of the two-part hub can also be made a part of the drive spindle on the recorder, which inner part can be coupled with the outer part when the drive spindle enters the cassette.

Abstract: The invention relates to a hub for magnetic tape cassettes, especially compact cassettes, and to magnetic tape cassettes possessing such hubs. In a first embodiment, spring means are provided on the inner periphery of the hub and exert radial pressures on the drive spindle, the spring means consisting, for example, of sprung teeth. In a further embodiment, the teeth have a spring rate of from about 1 P/mm to 40 P/mm. In another embodiment, the hub consists of an inner part and an outer part which can be coupled to one another and between which there is some play after coupling. A large number of specific examples of hubs are given to show possible shapes and arrangements of the teeth, and to show the types of material that can be used. In an advantageous embodiment, the inner part of the two-part hub can also be made a part of the drive spindle on the recorder, which inner part can be coupled with the outer part when the drive spindle enters the cassette.

Abstract: A cassette system for any type of recording medium in strip or tape form, such as films and magnetic tapes, consists essentially of a housing whose external dimensions match those of a conventional type of cassette, and a protective holder for the recording medium which is wound into at least one roll. The housing and the holder are separate or separable members and can be fitted together. Both are provided with means for inserting the holder into the housing in the correct position, and for introducing the recording medium into the transport apparatus. The housing is provided with opening and closing means. The holder can be designed to be separable from the roll of recording medium. Preferably, the housing is a precision-made article and the holder a low-cost article.

Abstract: A method and apparatus for measuring the electroacoustic properties of magnetic tapes by means of recorded test signals of varying frequency and amplitude, wherein measured values of the reproduced signals which depend on the biassing current and correspond to predetermined parameters are obtained; for each of the relevant values of the biassing current the amplitude of the test signal to the recorded is varied until the predetermined value of the reproduced signal is attained, and the measured value of the reproduced signal obtained in this way is registered, an amplitude-modulated test signal is recorded and, by means of a test programming unit and upon the attainment of a parameter value which controls this programming unit, the relevant measured value of the reproduced signal to be determined is transmitted to an intermediate storage device for further evaluation and the biassing current is varied in order to determine the next value to be measured.