Abstract: A phonograph stylus protection mechanism includes a protective zone defining member and a stylus deflector. The deflector moves the stylus to the protective zone during lateral deflection of the stylus to prevent stylus and record damage.

Abstract: An attachment for a phonograph pickup cartridge capable of removing static and stabilizing vibration of the cartridge body. A brush comprising bristles capable of engaging the inside of the grooves of a disc-type phonograph record is coupled to the cartridge body through a bearing which provides a mechanical resistance capable of damping both vertical and lateral vibrations. The brush is made from an electrical conductor, such as carbon, and is connected to the shield of the cartridge to remove static electricity from the surface and grooves of the record.

Abstract: A stylus guard assembly for use with a phonograph pick-up cartridge, which assembly includes a cam member, a manually operated lever with a pivot operating arm and walls providing detent surfaces. The pivot operating arm is disposed at an angle to a lever which engages a curved cam slot on a stylus guard. When the lever is manually displaced through its designated travel, the movement at the end of the arm, through the action of the cam mechanism, causes the guard to rotate on its pivot from one position to another. In one position, the guard is retracted to expose the stylus. In both positions, the guard is held in place by the detent mechanism. The manually operated lever produces a visual indication of the stylus guard position, which shows whether the stylus guard is in the position to allow the stylus tip to engage with the recording or is in the position to protect the stylus when not in use.

Abstract: A communications headset in which a unidirectional microphone at the end of a support boom is adjustably secured in a position selected by the wearer. The support boom is clamped under adjustable compression in a ball-and-socket arrangement which, at reduced compression, allows the boom to be moved longitudinally, pivoted about its axis, or pivoted about the center of the ball. The wearer turns a knob to compress the ball-and-socket joint to secure the boom in the position desired. A tube transmitting sound from the receiver to an ear plug is adjustably attached to the headset by means of a second ball-and-socket joint. A pivoting clamp attached to a pivoting temple member permits the microphone support assembly to be switched from one side of the head to the other as desired.

Abstract: A miniature acoustical transducer. The transducer includes a diaphragm, spring member and electromagnetic coils secured within a substantially cylindrical housing. The coils are arranged on opposite sides of the spring member. The spring member carries a permanent magnetic member and is connected to the diaphragm. Movement of the magnetic member relative to the electromagnetic coils varies the reluctance of the magnetic circuit defined by the coil and an associated core member.

Abstract: The disclosure describes improved apparatus for adjusting a unidirectional microphone in order to reduce the electrical output due to mechanical shocks applied to the microphone casing. The microphone includes a diaphragm supported by a housing which is resiliently mounted on the casing. The adjustment apparatus includes a mounting diaphragm positioned between the outer casing and the housing, and an enclosed chamber provided with an air leak which can alter the compliance and resistance of the mounting diaphragm in a controlled manner. A method of balancing the size or value of the elements of the microphone to provide pneumatic shock cancellation is also described.