Ultrasonic bubble detector

In ultrasonic bubble detection apparatus, a channel defined in the one-piece housing for receiving flow tubing in which bubbles are to be detected;

• first ultrasonic sending transducer means positioned in said housing on one side of said channel;
• second ultrasonic receiving transducer means positioned on the other side of said channel;
• aperture means respectively communicating between each of said first and second transducer means and said channel, said aperture means being filled with an elastomeric material capable of transmitting ultrasound energy between said channel and each transducer means;
• said housing having an air-containing slot positioned in the bottom of said channel of a width too small to contain the tubing positioned within said channel and being of a depth extending below the lower edge of each of said transducer means, to hinder the propagation of ultrasound energy through said housing from the first to the second transducer by a route other than one passing through said elastomeric material;
• each aperture means comprising a pair of apertures communicating between each of the first and second transducer means and said channel;
• the elastomeric material filling each aperture comprising a shape comprising a disk portion adjacent each of said first and second transducer means, each disk portion of elastomeric material being adhered at its outer face to a face of the adjoining transducer means, the elastomeric material carried in each aperture also comprising an elongated projection extending from said channel to the side of each disk portion opposed to the adjacent transducer means, said elongated projection of elastomeric material being integral with its adjacent disk portion of elastomeric material, whereby a bridging path of elastomeric material communicates directly from each transducer to said channel, extending inwardly of said channel to a degree sufficient to assure firm contact with flow tubing positioned in said channel;
• electric lead means communicating from each transducer means to the exterior of said housing, whereby tubing inserted in said channel may be in contact with said elastomeric material to provide transmission of ultrasound energy between the first and second transducers, which transmission of ultrasound energy is significantly altered by the presence of a bubble in the tubing, when compared with said tubing completely filled with liquid.