Abstract: A composite gun barrel 10 with active cooling having a breech end and a dharge end. The barrel includes an outer jacket 11 having radially inwardly projecting ports 15 proximate the breech end 25 extending inwardly from the outer diameter of the jacket, and an inner liner 13 inside the jacket and extending beyond the discharge end of the jacket prestressed by autofrettage to form a permanent integral assembly. The inner liner has a circumferentially located annular space 17, the ports being in operable communication with the annular space. A plurality of circumferentially spaced longitudinal channels 19 on the liner extend from the annular space to a location 21 beyond the discharge end of the jacket. The liner includes a shoulder 23 located between the breech end of the barrel and the inwardly projecting ports for locating the jacket on the liner.

Abstract: An electric horn has a diaphragm driven by a plunger which is vibrated by a coil having a pole piece. A small air gap between the plunger and the pole piece is required to assure that they will not touch during vibration. The gap is adjusted by assembling the horn with the gap small enough to permit the plunger to be pulled into contact with the pole piece by magnetic force when a preset direct current is applied to the coil. After assembly a calibration procedure is to apply the preset current to the coil, mechanically pull the pole piece away from the plunger until the diaphragm force overcomes the magnetic force causing the plunger and pole piece to separate, electrically detect the time of separation, and then stop or optionally pull the pole piece an additional fixed amount to set the required gap. Apparatus automatically performs the calibration procedure.

Abstract: An electric diaphragm horn includes a housing having a diaphragm mounted thereon defining a chamber, the chamber being vented to the atmosphere through the diaphragm.

Abstract: The invention pertains to electric horns for automobiles wherein a metal horn motor housing is assembled to a sound projector formed of synthetic plastic. A metal insert is molded into the projector having a metal flange extending from the projector adjacent a projector mounting surface whereby the insert flange is deformed upon the motor housing to produce an effective mechanical interconnection and assembly of the motor housing and projector.

Abstract: An electronic alarm particularly designed to indicate reverse movement of vehicles. The alarm utilizes a synthetic plastic housing having a cavity defined therein which intersects the housing at an exterior surface. A sound producing diaphragm, the motor for vibrating the diaphragm, and the electronic control circuit, are all mounted upon a diaphragm mounting assembly which is received within the housing cavity forming a cavity cover. The diaphragm is located in opposed relationship to a cavity sound reflective base, and an air passage surrounding the diaphragm mounting assembly transmits sound vibrations through the cavity, and through ports defined in the diaphragm assembly at the cavity opening.

Abstract: The invention pertains to an electric diaphragm horn and the method of air gap adjustment wherein the horn utilizes an electric coil mounted with a housing which includes a pole piece; a diaphragm being mounted upon the housing including a plunger to be spaced from the pole piece at a predetermined dimension to produce the desired sound output level. The housing bottom wall is deformed to an extent determined by measurements relative to the housing diaphragm mounting surface whereby assembly of the diaphragm to the housing produces a uniform gap between the pole piece and plunger resulting in a consistency of assembled dimensions. Further, the invention includes an electric horn construction utilizing a diaphragm wherein the motor chamber is vented to the atmosphere through a projector mounted upon the horn housing.