Abstract: A system for detecting abnormalities in a gas engine comprises: a pressure measuring device for measuring the pressure within each engine cylinder to generate corresponding signals; a device for determining from these signals the maximum pressure for every cycle of the engine operation; a comparator circuit for comparing each maximum pressure with reference values of a specific range and, when the maximum pressure is outside of that range, generating a corresponding signal indicating the existence of an abnormality; and an actuator operating in response to this signal to actuate and close a shut-off valve in the fuel gas supply line of the engine, an alarm device being simultaneously activated by this signal.

Abstract: A casing for holding a magnetic tape cassette which is formed into a box shape by bending and joining a blank of a transparent blastic plate material which has one surface, constituting the inner surface of a casing, on which grooves and a minutely roughened area are provided except for on a predetermined portion including at least one transparent window and the other surface, constituting the outer surface of said casing, on which printing and/or an uneven surface pattern is provided in a predetermined portion except for said transparent window.

Abstract: Apparatus for storing and retrieving individual file folders including a pair of symmetrical shelf units, positioned face to face and having a moveable column designed to move horizontally between the shelf units. A carriage is attached to the moveable column and is designed to move vertically between the shelf units. Store or retrieve commands are placed into the system via an operations table and in response to the commands individual file folders are stored and retrieved. Individual storage and retrieval is accomplished by apparatus designed to push aside adjoining file folders to gain access to a storage position and by code marks included on the shelf units to identify individual storage positions.