Abstract: An apparatus for selectively recirculating, conditioning, sorting and collecting the balls and discharging the bails from a pipe cleaning system utilizing recirculating foam rubber balls includes a housing having a dividing wall defining an inlet chamber on one side thereof and a collection chamber on the other side thereof, the inlet chamber having an inlet and the collection chamber having an outlet. A movable plate further divides the collection chamber into a acceptable ball chamber and a rejected ball chamber. A roller arrangement is operably connected with the housing and cooperates with the movable plate to condition and sort the balls in the system into the rejected ball chamber and the acceptable ball chamber. The collection chamber has a movable screen which selectively controls the flow of balls from the acceptable ball chamber to the outlet.

Abstract: An electronic siren apparatus has a primary horn with a throat which splits into matched secondary horns each having sides, an output end, a longitudinal axis, and a circumference. The secondary horns are folded back toward and around the primary horn and throat and the portions of the circumference of each end are joined. The folded secondary horns and the joined portions form a cavity which houses the primary horn and throat. A driver is operatively joined with the throat and is contained within the cavity for generating sound which is transmitted through the throat and primary horn, and then into each secondary horn and out the output ends in phase and amplitude matched relation. The area of the primary horn and the combined areas of the secondary horn, satisfy the equation ##EQU1## where x is the distance measured along the axis from the throat, cosh is the hyperbolic cosine function, d is the diameter of the primary horn and the combined diameters of the secondary horns, d.sub.

Abstract: According to the invention, a high-powered community alerting and warning device comprising a number of electromagnetic drivers is energized for tone generation by means of a rotary alternator that produces, when driven at a predetermined rotational speed, a sine-wave a.c. in the 400-800 Hz range. The alternator output is applied directly to the drivers, eliminating costly amplifier modules and energizing the drivers for better efficiency and reliability than an amplifier system. The alternator can be the output of a rotary frequency converter, or it can be driven by an engine or a separate electric motor.

Abstract: The outdoor alerting and warning device of this invention comprises numerous electronic drivers and an axially shallow drum-shaped resonance chamber having an inside diameter equal to a whole-number multiple of one-quarter of the wavelength of a sound wave of predetermined frequency. The drivers are mounted on the exterior of the resonance chamber, on its peripheral portion at regular circumferential intervals around it, with their ports opening into its interior. A coaxial outlet port in one end wall of the resonance chamber, having an area of between one-half and two times the total of driver port areas, opens into the throat of a horn; or each end wall may have such an outlet port, each opening into a horn throat.

Abstract: The stator of the sound generator in the siren of this invention is mounted on struts that diverge upwardly from the top of an upright post, with its axis coinciding with that of the post. The coaxial rotor of the sound generator is driven by a motor mounted on top of the stator. Sound from the generator is concentrated and directed by a horn that flares along its length from a closed end portion to a mouth. The closed end portion is dome-like and concentrically surrounds and covers the sound generator, opening unrestrictedly downwardly into a bottom portion of the horn that curves along its length so that the mouth, which is wholly spaced below the sound generator, opens to one side of the post. The post extends through a bottom wall portion of the horn. Rollers supported by the stator engage a downwardly facing annular track surface in the closed end portion of the horn to support the horn for rotation, one roller being rotatably driven from the siren motor to rotate the horn during siren operation.