Abstract: A movable shutter is provided for protecting the head of an information playback and/or recording unit when de-activated, the shutter having head-covering and head-uncovering positions which are stable positions provided by a bi-stable actuating member for the shutter. The bi-stable actuating member is linked to move the shutter at any position of relative movement between the head and the information support. A circuit including the head and the bi-stable actuating member is connected to a power source and the actuating member is operated instantaneously responsive to the unit being switched on and off so that the shutter is moved to and kept at its stable head-covering position immediately and without delay at the location where it has been interrupted upon loss of power to the head. In one embodiment a mechanical bi-stable actuating member is provided for moving the shutter to protect the head of a cassette-tape recording/playback unit.

Abstract: Cassette changer apparatus for a machine for recording and playing back information on magnetic tape contained in a cassette when located in an operative position. The cassette changer apparatus has a cassette storage magazine and cassette loading apparatus for transporting cassettes between the magazine and the operative position in the machine.A turntable supports the magazine for rotation about an axis extending through the inverting axis for a cassette in the magazine, so that operating the turntable to rotate the magazine one-half revolution inverts a cassette therein and positions both sets of recording racks on tape in the cassette upon transport to the operative position for use with a mechanism providing playback and/or recording upon a single direction of tape movement. The magazine in preferred embodiment has a plurality of compartments and is translatable to bring any compartment and cassette therein to loading position.