Abstract: A method for quickly and accurately positioning the rotary magnetic heads of a recorder/reader unit. The support for the magnetic heads includes a turntable and a countertable that are circular and that have a common axis of rotation, each including a peripheral support zone and a central support zone. The magnetic heads are situated around the periphery of the turntable. A screw enables the peripheral support zones to be brought into contact with each other and then the central support surfaces to be brought into contact with each other. The invention is applicable to recording and/or reading information on a magnetic tape.

Abstract: The invention relates to a method and to apparatus for quickly and accurately positioning the rotary magnetic heads of a recorder/reader unit. The support for the magnetic heads includes a turntable and a countertable that are circular and that have a common axis of rotation, each including a peripheral support zone and a central support zone. The magnetic heads are situated around the periphery of the turntable. A screw enables the peripheral support zones to be brought into contact with each other and then the central support surfaces to be brought into contact with each other. The invention is applicable to recording and/or reading information on a magnetic tape.

Abstract: A coupling for axially locking each reel of a cassette relative to the drive wheel of a magnetic recorder in which the drive wheel has an axial abutment against which the reel may bear. The reel is provided with a central recess having at least one rest projecting radially inward. The coupling includes a resilient locking device carried by the drive wheel and a controller slidably mounted within the drive wheel for actuating the resilient locking device between a retracted, rest position in which the reel can freely slide onto the drive wheel, and a working position in which the resilient locking device is pressed against the rest so that the reel can be axially locked against the axial abutment.

Abstract: A device for driving magnetic tape suitable for running from a pay-out spool to a take-up spool along a determined path during which the tape is wound through a given angle around a stationary element such as a cylindrical drum provided with rotary heads, and is caused to slip over the surface thereof, the device comprising first and second drive elements disposed respectively upstream and downstream from the element, wherein one of the drive elements includes a capstan and wherein the other one of the drive elements includes a wheel having the tape wound thereabout, the wheel being rotated so that its linear speed is greater than the linear speed of the tape and is in the same direction as the linear speed of the tape, and is suitable for enabling the tape to slip over the wheel.

Abstract: A device for guiding a magnetic tape suitable for being wound helically around a cylindrical drum and for running past at least one magnetic head driven in rotation around the periphery of a slot provided in an equatorial plane of the drum, the device being of the type comprising elongate bearing means linked to the drum and defining at least two bearing points against which one of the edges (bottom edge or top edge) of the tape may bear, the device including link means linking the bearing means to the drum and suitable for modifying the inclination of the bearing means as a function of temperature said link means suitable under the effect of differential thermal expansion to cause the bearing means to rotate about a radial axis (extending transversely to the axis of the drum) passing through a point which is invariant in rotation, and whose position is fixed regardless of temperature.