Security system for swimming pools and like bodies of water
First Claim
1. An apparatus for detecting a person in a body of water comprising:
- means for generating an electrical swept frequency signal having a frequency that continuously varies between upper and lower limits;
at least one pair of transducers disposed in a body of water including a transmitting transducer connected to receive the swept frequency signal for launching a beam of acoustical waves in response to the swept frequency signal in the body of water and a receiving transducer disposed opposite the transmitting transducer for receiving the acoustical waves and for converting received acoustical waves into an electrical received signal; and
means connected to the receiving transducer for producing a detected signal in response to the received signal and for initiating an alarm when the detected signal falls below a threshold for at least a predetermined length of time.
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Accused Products
Abstract
An apparatus for detecting a person in a body of water includes a transmitter for generating an electrical swept frequency signal having a frequency that continuously varies between upper and lower limits, at least one pair of transducers disposed in a body of water including a transmitting transducer connected to receive the swept frequency signal for launching a beam of acoustical waves in response to the swept frequency signal in the body of water and a receiving transducer disposed opposite the transmitting transducer for receiving the acoustical waves and for converting received acoustical waves into an electrical received signal, and a receiver connected to the receiving transducer for producing a detected signal in response to the received signal, for producing a threshold signal in response to the detected signal, and for initiating an alarm when the detected signal falls below the threshold for at least a predetermined length of time.
20 Citations
28 Claims
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1. An apparatus for detecting a person in a body of water comprising:
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means for generating an electrical swept frequency signal having a frequency that continuously varies between upper and lower limits; at least one pair of transducers disposed in a body of water including a transmitting transducer connected to receive the swept frequency signal for launching a beam of acoustical waves in response to the swept frequency signal in the body of water and a receiving transducer disposed opposite the transmitting transducer for receiving the acoustical waves and for converting received acoustical waves into an electrical received signal; and means connected to the receiving transducer for producing a detected signal in response to the received signal and for initiating an alarm when the detected signal falls below a threshold for at least a predetermined length of time. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An apparatus for detecting a person in a body of water comprising:
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means for generating an electrical transmission signal; at least one pair of transducers disposed in a body of water including a transmitting transducer connected to receive the electrical transmission signal for launching a beam of acoustical waves in response to the electrical transmission signal in the body of water and a receiving transducer disposed opposite the transmitting transducer for receiving the acoustical waves and for converting received acoustical waves into an electrical received signal; and means connected to the receiving transducer for producing a detected signal in response to the received signal, for producing a threshold signal in response to and determined by the detected signal, and for initiating an alarm when the detected signal falls below the threshold signal for at least a predetermined length of time. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. An apparatus for detecting a person in a body of water comprising:
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means for generating an electrical transmission signal; at least one pair of transducers disposed in a body of water including a transmitting transducer connected to receive the electrical transmission signal for launching a beam of acoustical waves in response to the electrical transmission signal in the body of water and a receiving transducer disposed opposite the transmitting transducer for receiving the acoustical waves and for converting received acoustical waves into an electrical received signal having a magnitude indicative of received acoustical wave intensity; and means connected to the receiving transducer for producing a detected signal in response to the received signal, the detected signal having a magnitude indicative of the magnitude of the received signal, for producing a threshold signal having a magnitude varying in response to the magnitude of the detected signal, and for initiating an alarm when the magnitude of the detected signal falls below the magnitude of the threshold signal for at least a predetermined length of time. - View Dependent Claims (22, 23, 24, 25, 26, 27)
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28. An apparatus for detecting a person in a body of water comprising:
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means for generating an electrical swept frequency signal having a frequency that continuously varies between upper and lower limits; at least one pair of transducers disposed in a body of water including a transmitting transducer connected to receive the swept frequency signal for launching a beam of acoustical waves in response to the swept frequency signal in the body of water and a receiving transducer disposed opposite the transmitting transducer for receiving the acoustical waves and for converting received acoustical waves into an electrical received signal having a magnitude indicative of received acoustical wave intensity; and means connected to the receiving transducer for producing a detected signal in response to the received signal, the detected signal having a magnitude indicative of the magnitude of the received signal, for producing a threshold signal having a magnitude varying in response to the magnitude of the detected signal, and for initiating an alarm when the magnitude of the detected signal falls below the magnitude of the threshold for at least a predetermined length of time.
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Specification