An instruction set for solving a specific mathematical problem includes a column of sheet material for manual entry of data in appropriate horizontal spaces as designated by the instruction set. The spaces include color indicia corresponding to color indicia appearing on function keys of an electronic calculator. A carrier is provided to receive the sheet material column with the carrier being slidably received within the calculator. The calculator includes an aperture which successively exposes...

A transistor integrated circuit particularly for use in transaction cards such as credit cards or payment cards comprises conductive film zones on the surface of the circuit having a shape and layout which makes it difficult or impossible to determine the layout of the circuit. Additional metal zones may be formed at the level or below the level of the transistor connection strips, which cannot be eliminated without eliminating the strips. Alternatively, instead of strips, metal zones extended i...

A plurality of nodes of split vibration of a diaphragm are driven by a plurality of voice coils to prevent split vibration of the diaphragm. The voice coils are inserted between three or more layers of magnetic poles respectively and driven by a magnetic circuit including a plurality of magnets magnetized in the same direction as the vibration of the voice coils.

An earphone comprising a housing formed on the outer periphery of the front face with a flange for preventing the housing from disengagement from the concha when the housing is received in a recess of the concha, said housing being sized to be received in the recess of the concha and having an electroacaustic transducer built in.

A time recorder having an assembly with structure for reading out a personal code recorded on an inserted time card, a memory provided corresponding to each personal code for storing status data expressing at least the distinction of either "arrival queuing" or "departure queuing", a print column control for making reference to status storage corresponding to the personal code read out by a read-out at the time of receiving of the time card and also for printing the time of receiving of the time...

A lock for securing a telephone instrument against unauthorized use includes a key-operated cylinder extending through a wall of the housing of the telephone instrument and including a cam movable between locked and unlocked positions for engaging the line switch of the telephone instrument in the locked position and maintaining the line switch in a disconnect position so long as the lock remains in the locked position.

An automatic bank note transaction apparatus comprises a first unit detachably mounted in a housing and including safes disposed at one side thereof and a second unit provided in the housing, adjacent to and detachably mounted on the first unit and connected to a bank note dispensing port of the housing. Since the first unit can be turned back to front with respect to the second unit, the most suitable operating mode, that is, a front-operation mode or a rear-operation mode, can be arbitrarily s...

Headphone earpieces which comprise each at least one electroacoustic transducer operating on the orthodynamic principle and including a small-mass diaphragm of an extension corresponding at least to that of an average auricle, with the coupling space of each of the earpieces being designed for a minimum reflection, are equipped with an ear cushion which, with the headphone in position of use, tightly encloses the coupling space toward the outside. The disadvantages of headphone with an orthodyna...

A loudspeaker horn is described, which produces good coupling of sound to the atmosphere, while avoiding perturbations in magnitude and phase that would produce large narrow-frequency losses or transient distortions. The horn includes a major sound-reflective portion of typical horn shape, and also includes a buffer extending around the large end of the horn. The buffer has a sound absorption coefficient about halfway between the almost zero absorption coefficient of the major portion of the bou...

An improved electronic key for use in combination with an electrical receptacle adapted to receive the key wherein switch contacts on the key are designed for making electrical contact with corresponding receptacle contacts when the key is turned in the receptacle to an "on" position only after the other key contacts make electrical contact with the corresponding receptacle contacts. Conversely, the switch contacts are the first to break electrical contact when the key is turned past the "on" po...