Apparatus and method for detecting swimmers

Claim 1

An apparatus for detecting the presence of a person in a body of water comprising: a plurality of pairs of transducers, each pair including a transmitting transducer for launching ultrasonic waves in a body of water in response to application of an excitation signal and a receiving transducer for receiving ultrasonic waves and for generating a reception signal indicative of receipt of ultrasonic waves, the transducers in each pair being disposed for the launching and reception of ultrasonic waves by and between them, each transducer pair defining a channel, the plurality of transducer pairs defining a corridor; means for repeatedly applying a pulsed excitation signal to the transmitting transducer of a first of the channels in a corridor; means for sequentially transferring the excitation signal to a transmitting transducer of a second through a last of the channels in the corridor upon generation of a reception signal by the receiving transducers of said first through the channel immediately preceding the last channel in the corridor, respectively, and for transferring the excitation signal to an alarm means upon the generation of a reception signal by the receiving transducer in the last channel, a person disposed in the body of water in one of the channels inhibiting generation of a reception signal by the receiving transducer in that channel and thereby preventing further transfer of the excitation signal; and alarm means responsive to the receiving transducer in the last channel for indicating a failure by at least one of said receiving transducers to generate a reception signal in response to the excitation signal.

Claim 2

An apparatus for detecting the presence of a person in a body of water comprising: a plurality of pairs of transducers, each pair including a transmitting transducer for launching ultrasonic waves in a body of water in response to application of an excitation signal and a receiving transducer for receiving ultrasonic waves and for generating a reception signal indicative of receipt of ultrasonic waves, the transducers in each pair being disposed for the launching and reception of ultrasonic waves by and between them, each transducer pair defining a channel, the plurality of transducer pairs defining a corridor; means for repeatedly applying a pulsed excitation signal to the transmitting transducer of a first of the channels in a corridor; means for sequentially transferring the excitation signal to a transmitting transducer of a second through a last of the channels in the corridor upon generation of a reception signal by the receiving transducers of said first through the channel immediately preceding the last channel in the corridor, respectively, and for transferring the excitation signal to an alarm means upon the generation of a reception signal by the receiving transducer in the last channel, a person disposed in the body of water in one of the channels inhibiting generation of a reception signal by the receiving transducer in that channel and thereby preventing further transfer of the excitation signal; and alarm means responsive to the receiving transducer in the last channel for indicating a failure by at least one of said receiving transducers to generate a reception signal in response to the excitation signal.

Claim 24

An apparatus for detecting the presence of a person in a body of water comprising: a plurality of pairs of transducers, each pair including a transmitting transducer for launching ultrasonic waves in a body of water in response to application of an excitation signal and a receiving transducer for receiving ultrasonic waves and for generating a reception signal indicative of receipt of ultrasonic waves, the transducers in each pair being disposed for the launching and reception of ultrasonic waves by and between them, each transducer pair defining a channel, the plurality of transducer pairs defining a corridor; means for repeatedly applying a pulsed excitation signal to the transmitting transducer of a first of the channels in a corridor; a relay associated with each channel, each relay including an electromagnetic coil and a movable contact having first and second positions, biased to the first position for applying the excitation signal to the transmitting transducer of the associated channel and movable to the second position upon energization of said coil to transfer the excitation signal wherein, upon generation of a reception signal by the receiving transducer of the first channel, the coil of the relay associated with the first channel is energized to transfer the excitation signal to the transmitting transducer of the second channel, the excitation signal transfer continuing sequentially by operation of the respective relays in cascade through each of said channels upon generation of a reception signal by the receiving transducer in the preceding channel, a person disposed in the body of water in one of said channels inhibiting generation of a reception signal by the receiving transducer in that channel and thereby preventing actuation of at least one of said relays and the further transfer of the excitation signal; alarm means responsive to the excitation signal for indicating a failure of actuation of at least one of said relays; and delay means responsive to the excitation signal transferred by the relay in the last channel upon the generation of a reception signal by the receiving transducer in the last channel for delaying operation of said alarm means until the prevention of actuation of at least one of said relays has continued for a preselected time period.

Claim 25

An apparatus for detecting the presence of a person in a body of water comprising: a plurality of pairs of transducers, each pair including a transmitting transducer for launching ultrasonic waves in a body of water in response to application of an excitation signal and a receiving transducer for receiving ultrasonic waves and for generating a reception signal indicative of receipt of ultrasonic waves, the transducers in each pair being disposed for the launching and reception of ultrasonic waves by and between them, each transducer pair defining a channel, the plurality of transducer pairs defining a corridor; means for repeatedly applying a pulsed excitation signal to the transmitting transducer of a first of the channels in a corridor; a relay associated with each channel, each relay including an electromagnetic coil and a movable contact having first and second positions, biased to the first position for applying the excitation signal to the transmitting transducer of the associated channel and movable to the second position upon energization of said coil to transfer the excitation signal wherein, upon generation of a reception signal by the receiving transducer of the first channel, the coil of the relay associated with the first channel is energized to transfer the excitation signal to the transmitting transducer of the second channel, the excitation signal transfer continuing sequentially by operation of the respective relays in cascade through each of said channels upon generation of a reception signal by the receiving transducer in the preceding channel, a person disposed in the body of water in one of said channels inhibiting generation of a reception signal by the receiving transducer in that channel and thereby preventing actuation of at least one of said relays and the further transfer of the excitation signal; alarm means responsive to the excitation signal for indicating a failure of actuation of at least one of said relays; and delay means responsive to the excitation signal transferred by the relay in the last channel upon the generation of a reception signal by the receiving transducer in the last channel for delaying operation of said alarm means until the prevention of actuation of at least one of said relays has continued for a preselected time period.

Claim 26

An apparatus for detecting the presence of a person in a body of water comprising: a plurality of pairs of transducers, each pair including a transmitting transducer for launching ultrasonic waves in a body of water in response to application of an excitation signal and a receiving transducer for receiving ultrasonic waves and for generating a reception signal indicative of receipt of ultrasonic waves, the transducers in each pair being disposed for the launching and reception of ultrasonic waves by and between them, each transducer pair defining a channel, the plurality of transducer pairs defining a corridor; means for sequentially and repeatedly applying an excitation signal to the transmitting transducer in a corridor including amplifiers associated with each of the channels for passing a continuous excitation signal to the transmitting transducer of the associated channel and for amplifying the signal produced by the receiving transducer of the associated channel upon the reception of ultrasonic waves and a pulsed direct current power supply connected to the amplifiers for supplying an activation signal repeatedly and sequentially activating said amplifiers in the respective channels; a relay associated with each channel, each relay including an electromagnetic coil and a movable contact having first and second positions, biased to the first position for applying the excitation signal to the transmitting transducer of the associated channel and movable to the second position upon energization of said coil to transfer the activation signal wherein, upon generation of a reception signal by the receiving transducer of the first channel, the coil of the relay associated with the first channel is energized to transfer the activation signal to the transmitting transducer of the second channel, the activation signal transfer continuing sequentially by operation of the respective relays in cascade through each of said channels upon generation of a reception signal by the receiving transducer in the preceding channel, a person disposed in the body of water in one of said channels inhibiting generation of a reception signal by the receiving transducer in that channel and thereby preventing actuation of at least one of said relays and the further transfer of the activation signal; alarm means responsive to the activation signal for indicating a failure of actuation of at least one of said relays; and delay means responsive to the activation signal transferred by the relay in the last channel upon the generation of a reception signal by the receiving transducer in the last channel for delaying operation of said alarm means until the prevention of actuation of at least one of said relays has continued for a preselected time period.

Claim 27

An apparatus for detecting the presence of a person in a body of water comprising: a plurality of pairs of transducers, each pair including a transmitting transducer for launching ultrasonic waves in a body of water in response to application of an excitation signal and a receiving transducer for receiving ultrasonic waves and for generating a reception signal indicative of receipt of ultrasonic waves, the transducers in each pair being disposed for the launching and reception of ultrasonic waves by and between them, each transducer pair defining a channel, the plurality of transducer pairs defining a corridor; means for sequentially and repeatedly applying an excitation signal to the transmitting transducer in a corridor including amplifiers associated with each of the channels for passing a continuous excitation signal to the transmitting transducer of the associated channel and for amplifying the signal produced by the receiving transducer of the associated channel upon the reception of ultrasonic waves and a pulsed direct current power supply connected to the amplifiers for supplying an activation signal repeatedly and sequentially activating said amplifiers in the respective channels; a relay associated with each channel, each relay including an electromagnetic coil and a movable contact having first and second positions, biased to the first position for applying the excitation signal to the transmitting transducer of the associated channel and movable to the second position upon energization of said coil to transfer the activation signal wherein, upon generation of a reception signal by the receiving transducer of the first channel, the coil of the relay associated with the first channel is energized to transfer the activation signal to the transmitting transducer of the second channel, the activation signal transfer continuing sequentially by operation of the respective relays in cascade through each of said channels upon generation of a reception signal by the receiving transducer in the preceding channel, a person disposed in the body of water in one of said channels inhibiting generation of a reception signal by the receiving transducer in that channel and thereby preventing actuation of at least one of said relays and the further transfer of the activation signal; alarm means responsive to the activation signal for indicating a failure of actuation of at least one of said relays; and delay means responsive to the activation signal transferred by the relay in the last channel upon the generation of a reception signal by the receiving transducer in the last channel for delaying operation of said alarm means until the prevention of actuation of at least one of said relays has continued for a preselected time period.

Claim 28

A method of detecting the presence of a person in a body of water comprising: repeatedly applying an excitation signal to a first transmitting transducer to launch ultrasonic waves through a body of water toward a first receiving transducer, the first transmitting and receiving transducers comprising a first pair of a plurality of pairs of transducers, each pair defining a channel and said plurality of pairs defining a corridor within the body of water, the transducers in each pair being disposed for the launching and reception of ultrasonic waves by and between them; upon generation of a reception signal by the receiving transducer of the first channel indicating the receipt of the ultrasonic waves, transferring the excitation signal to the transmitting transducer of a second of said channels to launch an ultrasonic wave toward the receiving transducer in said second channel; continuing to transfer the excitation signal sequentially to each subsequent transmitting transducer upon generation of a reception signal by the receiving transducer in each preceding channel, respectively, a person disposed in the body of water in one of said channels inhibiting generation of a reception signal by the receiving transducer in that channel and thereby preventing further transfer of the excitation signal; monitoring the generation of a reception signal by the receiving transducer in the last of said channels; and triggering an alarm when no reception signal is generated by the receiving transducer of the last of said channels.

Claim 29

A method of detecting the presence of a person in a body of water comprising: repeatedly applying an excitation signal to a first transmitting transducer to launch ultrasonic waves through a body of water toward a first receiving transducer, the first transmitting and receiving transducers comprising a first pair of a plurality of pairs of transducers, each pair defining a channel and said plurality of pairs defining a corridor within the body of water, the transducers in each pair being disposed for the launching and reception of ultrasonic waves by and between them; upon generation of a reception signal by the receiving transducer of the first channel indicating the receipt of the ultrasonic waves, transferring the excitation signal to the transmitting transducer of a second of said channels to launch an ultrasonic wave toward the receiving transducer in said second channel; continuing to transfer the excitation signal sequentially to each subsequent transmitting transducer upon generation of a reception signal by the receiving transducer in each preceding channel, respectively, a person disposed in the body of water in one of said channels inhibiting generation of a reception signal by the receiving transducer in that channel and thereby preventing further transfer of the excitation signal; monitoring the generation of a reception signal by the receiving transducer in the last of said channels; and triggering an alarm when no reception signal is generated by the receiving transducer of the last of said channels.