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US5319735A Expired / Lapsed US ⏱️ 0.0 years remaining

Embedded signalling

Assignee: Merrill Lynch Capital Corp
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Filing: 1991-12-17
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Granted: 1994-06-07
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Expires: 2011-12-17
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Abstract

Abstract A code signal representing a sequence of code symbols carrying digital information is generated with the frequency components of the code signal being essentially confined to a preselected signalling band lying within the bandwidth of an audio signal within which the code signal is to be embedded. The audio signal is continuously frequency analyzed over a frequency band encompassing the signalling band and the code signal is dynamically filtered as a function of the analysis thereby to provide a modified code signal with frequency components which are, at each time instant, essentially a preselected small proportion of the levels of the corresponding audio signal frequency components. Accordingly, the modified code signal can be combined with the audio signal to obtain a composite audio signal which is not readily distinguishable from the original audio signal by listening. Furthermore, the digital information can be recovered from the composite audio signal by a procedure which is essentially the compliment of that used to obtain the composite audio signal.

Inventors

  • 👤 Robert D. Preuss
  • 👤 Salim E. Roukos
  • 👤 A. W. F. Huggins
  • 👤 Herbert Gish
  • 👤 Marcos A. Bergamo
  • 👤 Patrick M. Peterson
  • 👤 Alan G. Derr

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 12:12
CPC Classifications
H; H04; H04L; H04L5/00; G; G11; G11B; G11B20/00; G11B20/00086; G11B20/00884; G11B20/00913; G10; G10L; G10L19/00; G10L19/018; G11B20/10; G11B20/10009; G11B20/10527; G11B20/18; G11B20/1806; G11B20/1813; H03; H03M; H03M5/00; H03M5/02; H03M5/04; H04B; H04B1/00; H04B1/66; H04B1/665; H04B1/69; H04B1/707

Claims Analysis

Total Claims: 37
Claim 1
Independent Claim 138 words
A method of embedding a sequence of code symbols in an audio signal, said method comprising: generating a code signal representing the sequence of code symbols and with frequency components essentially confined to a preselected signalling band lying within the bandwidth of said audio signal; continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamically filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which, at each time instant, are essentially negligibly small outside said signalling band and, at each frequency within said signalling band, are essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range; and combining said modified code signal with said audio signal thereby to provide a composite audio signal.
Claim 2
Independent Claim 138 words
A method of embedding a sequence of code symbols in an audio signal, said method comprising: generating a code signal representing the sequence of code symbols and with frequency components essentially confined to a preselected signalling band lying within the bandwidth of said audio signal; continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamically filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which, at each time instant, are essentially negligibly small outside said signalling band and, at each frequency within said signalling band, are essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range; and combining said modified code signal with said audio signal thereby to provide a composite audio signal.
Claim 3
Dependent Claim 39 words
The method as set forth in claim 1 wherein said code signal is generated by generating a corresponding pseudorandom number sequence for each symbol input; upsampling and lowpass filtering said sequences; and transposing upwards in frequency the filtered sequence.
Claim 4
Independent Claim 102 words
A method of detecting a sequence of predetermined code symbols which is represented by a code signal embedded in a composite audio signal, said method comprising: continuously frequency analyzing said composite audio signal over a frequency band encompassing a preselected signalling band lying within the bandwidth of said composite audio signal; within said signalling band, filtering said composite audio signal as a converse function of the analysis thereby to provide an essentially even energy distribution over said signalling band; and applying said filtered signal to a set of filters, each filter in said set being matched to one of said code symbols.
Claim 5
Independent Claim 102 words
A method of detecting a sequence of predetermined code symbols which is represented by a code signal embedded in a composite audio signal, said method comprising: continuously frequency analyzing said composite audio signal over a frequency band encompassing a preselected signalling band lying within the bandwidth of said composite audio signal; within said signalling band, filtering said composite audio signal as a converse function of the analysis thereby to provide an essentially even energy distribution over said signalling band; and applying said filtered signal to a set of filters, each filter in said set being matched to one of said code symbols.
Claim 6
Independent Claim 217 words
A method of transmitting a sequence of code symbols over a channel carrying an audio signal, said method comprising: generating a code signal representing the sequence of code symbols and with frequency components essentially confined to a preselected signalling band lying within the bandwidth of said audio signal; continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamically filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are, at each time instant, essentially negligibly small outside said signalling band and, at each frequency within said signalling band, essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range; combining said modified code signal with said audio signal thereby to provide a composite audio signal and transmitting said composite audio signal over said channel; continuously frequency analyzing the received composite audio signal over a frequency band encompassing said preselected signalling band; within said signalling band, filtering said received composite audio signal as a converse function of the analysis thereby to provide an essentially even energy distribution over said signalling band; and applying said filtered signal to a set of filters, each filter in said set being matched to one of the code symbols.
Claim 7
Independent Claim 217 words
A method of transmitting a sequence of code symbols over a channel carrying an audio signal, said method comprising: generating a code signal representing the sequence of code symbols and with frequency components essentially confined to a preselected signalling band lying within the bandwidth of said audio signal; continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamically filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are, at each time instant, essentially negligibly small outside said signalling band and, at each frequency within said signalling band, essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range; combining said modified code signal with said audio signal thereby to provide a composite audio signal and transmitting said composite audio signal over said channel; continuously frequency analyzing the received composite audio signal over a frequency band encompassing said preselected signalling band; within said signalling band, filtering said received composite audio signal as a converse function of the analysis thereby to provide an essentially even energy distribution over said signalling band; and applying said filtered signal to a set of filters, each filter in said set being matched to one of the code symbols.
Claim 8
Dependent Claim 39 words
The method as set forth in claim 4 wherein said code signal is generated by generating a corresponding pseudorandom number sequence for each symbol input; upsampling and lowpass filtering said sequence; and transposing upwards in frequency the filtered sequence.
Claim 9
Dependent Claim 34 words
The method as set forth in claim 4 wherein said audio signal has a bandwidth in the order of about 20 k Hz and said signalling band has a bandwidth of about 8800 Hz.
Claim 10
Dependent Claim 21 words
The method as set forth in claim 6 wherein said signalling band is centered on a frequency of about 6300 Hz.
Claim 11
Dependent Claim 27 words
The method as set forth in claim 7 wherein said symbols are sequentially encoded in said code signal at a rate of about 4.3 symbols per second.
Claim 12
Dependent Claim 30 words
The method as set forth in claim 4 wherein said preselected proportion represents a modified code signal level which is about 19 dB below the level of the audio signal.
Claim 13
Independent Claim 136 words
A method of embedding a sequence of code symbols in an audio signal, said method comprising: for each symbol input, generating a corresponding pseudorandom sequence representing the respective symbol; upsampling, filtering and transposing said code sequences thereby to generate a code signal having frequency components essentially confined to a preselected signalling band lying within the bandwidth of said audio signal; continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamically filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are at each time instant essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range; combining said modified code signal with said audio signal thereby to provide a composite audio signal.
Claim 14
Independent Claim 136 words
A method of embedding a sequence of code symbols in an audio signal, said method comprising: for each symbol input, generating a corresponding pseudorandom sequence representing the respective symbol; upsampling, filtering and transposing said code sequences thereby to generate a code signal having frequency components essentially confined to a preselected signalling band lying within the bandwidth of said audio signal; continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamically filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are at each time instant essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range; combining said modified code signal with said audio signal thereby to provide a composite audio signal.
Claim 15
Independent Claim 270 words
A method of transmitting a sequence of code symbols selectable from a predetermined alphabet and occurring at a rate of about 4.3 per second over a channel carrying an audio signal having a bandwidth in the order of 20 k HZ, said method comprising: generating a code signal representing the sequence of code symbols and having frequency components essentially confined to a preselected signalling band having a bandwidth of about 8800 Hz centered on a frequency of about 6300 Hz; continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamically filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are, at each time instant, essentially negligibly small outside said signalling band and, at each frequency within said signalling band, essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range, said preselected proportion representing a modified code signal level which is about 19 dB below the level of said audio signal; combining said modified code signal with said audio signal thereby to provide a composite audio signal and transmitting said composite audio signal over said channel; continuously frequency analyzing the received composite audio signal over a frequency band encompassing said preselected signalling band; within said signalling band, filtering said received composite audio signal as a converse function of the analysis thereby to provide an essentially even energy distribution over said signalling band; and applying said filtered signal to a set of filters, each filter in said set being matched to one of said code symbols.
Claim 16
Independent Claim 270 words
A method of transmitting a sequence of code symbols selectable from a predetermined alphabet and occurring at a rate of about 4.3 per second over a channel carrying an audio signal having a bandwidth in the order of 20 k HZ, said method comprising: generating a code signal representing the sequence of code symbols and having frequency components essentially confined to a preselected signalling band having a bandwidth of about 8800 Hz centered on a frequency of about 6300 Hz; continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamically filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are, at each time instant, essentially negligibly small outside said signalling band and, at each frequency within said signalling band, essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range, said preselected proportion representing a modified code signal level which is about 19 dB below the level of said audio signal; combining said modified code signal with said audio signal thereby to provide a composite audio signal and transmitting said composite audio signal over said channel; continuously frequency analyzing the received composite audio signal over a frequency band encompassing said preselected signalling band; within said signalling band, filtering said received composite audio signal as a converse function of the analysis thereby to provide an essentially even energy distribution over said signalling band; and applying said filtered signal to a set of filters, each filter in said set being matched to one of said code symbols.
Claim 17
Dependent Claim 39 words
The method as set forth in claim 11 wherein said code signal is generated by generating a corresponding pseudorandom number sequence for each symbol input; upsampling and lowpass filtering said sequence; and transposing upwards in frequency the filtered sequence.
Claim 18
Independent Claim 244 words
A method of communicating code symbols over a channel carrying an audio signal, said method comprising: for each symbol input, generating a corresponding pseudorandom sequence baseband signal representing the respective symbol; filtering and transposing upward in frequency said pseudorandom sequences thereby to generate a code signal having frequency components essentially confined to a preselected signalling band lying within the bandwidth of said audio signal; continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamically filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are, at each time instant and at each frequency within said signalling band, essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range; combining said modified code signal with said audio signal thereby to provide a composite audio signal and transmitting said composite audio signal over said channel; continuously frequency analyzing the received composite audio signal over a frequency band encompassing said preselected signalling band; within said signalling band, filtering said received composite audio signal as a converse function of the analysis thereby to provide an essentially even energy distribution over said signalling band; transposing components in said signalling band downward in frequency to obtain a received baseband signal; and applying said received baseband signal to a set of filters, each filter in said set being matched to one of the pseudorandom sequences representing symbols.
Claim 19
Independent Claim 244 words
A method of communicating code symbols over a channel carrying an audio signal, said method comprising: for each symbol input, generating a corresponding pseudorandom sequence baseband signal representing the respective symbol; filtering and transposing upward in frequency said pseudorandom sequences thereby to generate a code signal having frequency components essentially confined to a preselected signalling band lying within the bandwidth of said audio signal; continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamically filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are, at each time instant and at each frequency within said signalling band, essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range; combining said modified code signal with said audio signal thereby to provide a composite audio signal and transmitting said composite audio signal over said channel; continuously frequency analyzing the received composite audio signal over a frequency band encompassing said preselected signalling band; within said signalling band, filtering said received composite audio signal as a converse function of the analysis thereby to provide an essentially even energy distribution over said signalling band; transposing components in said signalling band downward in frequency to obtain a received baseband signal; and applying said received baseband signal to a set of filters, each filter in said set being matched to one of the pseudorandom sequences representing symbols.
Claim 20
Dependent Claim 150 words
Apparatus for combining a sequence of code symbols with an audio signal, said apparatus comprising: means for generating a corresponding code signal representing the sequence of code symbols, said code signal comprising frequency components essentially confined to a preselected signalling band lying within the bandwidth of said audio signal; means for continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamic filter means for selectively filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are, at each time instant, essentially negligibly small outside said signalling band and, at each frequency within said signalling band, are essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range; and means for combining said modified code signal with said audio signal thereby to provide a composite audio signal.
Claim 21
Dependent Claim 150 words
Apparatus for combining a sequence of code symbols with an audio signal, said apparatus comprising: means for generating a corresponding code signal representing the sequence of code symbols, said code signal comprising frequency components essentially confined to a preselected signalling band lying within the bandwidth of said audio signal; means for continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamic filter means for selectively filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are, at each time instant, essentially negligibly small outside said signalling band and, at each frequency within said signalling band, are essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range; and means for combining said modified code signal with said audio signal thereby to provide a composite audio signal.
Claim 22
Dependent Claim 33 words
Apparatus as set forth in claim 14 wherein said audio signal has a bandwidth in the order of about 20 k Hz and said signalling band has a bandwidth of about 8800 Hz.
Claim 23
Dependent Claim 20 words
Apparatus as set forth in claim 15 wherein said signalling band is centered on a frequency of about 6300 Hz.
Claim 24
Dependent Claim 26 words
Apparatus as set forth in claim 16 wherein said symbols are sequentially encoded in said code signal at a rate of about 4.3 symbols per second.
Claim 25
Dependent Claim 29 words
Apparatus as set forth in claim 14 wherein said preselected proportion represents a modified code signal level which is about 19 dB below the level of the audio signal.
Claim 26
Dependent Claim 116 words
Apparatus for extracting a sequence of code symbols which are represented by respective pseudorandom sequences embedded in a composite audio signal, said apparatus comprising: means for continuously frequency analyzing said composite audio signal over a frequency band encompassing a preselected signalling band lying within the bandwidth of the composite audio signal; dynamic filtering means for selectively filtering said composite audio signal within said signalling band as a converse function of said analysis thereby to provide a modified audio signal having an essentially even energy distribution over said signalling band; and a set of matched filters responsive to said modified signal, each filter in said set being matched to one of the pseudorandom sequences representing said symbols.
Claim 27
Dependent Claim 116 words
Apparatus for extracting a sequence of code symbols which are represented by respective pseudorandom sequences embedded in a composite audio signal, said apparatus comprising: means for continuously frequency analyzing said composite audio signal over a frequency band encompassing a preselected signalling band lying within the bandwidth of the composite audio signal; dynamic filtering means for selectively filtering said composite audio signal within said signalling band as a converse function of said analysis thereby to provide a modified audio signal having an essentially even energy distribution over said signalling band; and a set of matched filters responsive to said modified signal, each filter in said set being matched to one of the pseudorandom sequences representing said symbols.
Claim 28
Dependent Claim 197 words
Apparatus for combining a sequence of code symbols occurring at a rate of about 4.3 per second with an audio signal having a bandwidth in the order of 20 k HZ, said apparatus comprising: means for generating a corresponding code signal representing the sequence of code symbols, said code signal comprising frequency components essentially confined to a preselected signalling band having a bandwidth of about 8800 Hz centered on a frequency of about 6300 Hz; means for continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamic filter means for selectively filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are, at each time instant, essentially negligibly small outside said signalling band and, at each frequency within said signalling band, are essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range, said preselected proportion representing a modified code signal level which is about 19 dB below the level of said audio signal; and means for combining said modified code signal with said audio signal thereby to provide a composite audio signal.
Claim 29
Dependent Claim 197 words
Apparatus for combining a sequence of code symbols occurring at a rate of about 4.3 per second with an audio signal having a bandwidth in the order of 20 k HZ, said apparatus comprising: means for generating a corresponding code signal representing the sequence of code symbols, said code signal comprising frequency components essentially confined to a preselected signalling band having a bandwidth of about 8800 Hz centered on a frequency of about 6300 Hz; means for continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamic filter means for selectively filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are, at each time instant, essentially negligibly small outside said signalling band and, at each frequency within said signalling band, are essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range, said preselected proportion representing a modified code signal level which is about 19 dB below the level of said audio signal; and means for combining said modified code signal with said audio signal thereby to provide a composite audio signal.
Claim 30
Dependent Claim 148 words
Apparatus for combining a sequence of code symbols with an audio signal, said apparatus comprising: means for generating a corresponding binary code sequence representing each successive symbol; means for filtering and transposing information bearing frequency components of said code sequences thereby to generate a code signal having frequency components essentially confined to a preselected signalling band lying within the bandwidth of said audio signal; means for continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamic filter means for selectively filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are, at each time instant, essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range; means for combining said modified code signal with said audio signal thereby to provide a composite audio signal.
Claim 31
Dependent Claim 148 words
Apparatus for combining a sequence of code symbols with an audio signal, said apparatus comprising: means for generating a corresponding binary code sequence representing each successive symbol; means for filtering and transposing information bearing frequency components of said code sequences thereby to generate a code signal having frequency components essentially confined to a preselected signalling band lying within the bandwidth of said audio signal; means for continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamic filter means for selectively filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are, at each time instant, essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range; means for combining said modified code signal with said audio signal thereby to provide a composite audio signal.
Claim 32
Dependent Claim 42 words
The apparatus as set forth in claim 21 wherein said code signal is generated by generating a corresponding pseudorandom sequence for each symbol input; low pass filtering said sequences; and transposing upwards in frequency the information bearing components of the filtered sequence.
Claim 33
Dependent Claim 158 words
An audio recording comprising a medium carrying a composite signal which is a mixture of an audio signal and a dynamically modified code signal representing a sequence of code symbols wherein said dynamically modified code signal is obtained by: generating a code signal representing the sequence of symbols with frequency components essentially confined to a preselected signalling band lying within the bandwidth of said audio signal; continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamically filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are, at each time instant, essentially negligibly small outside said signalling band and, at each frequency within said signalling band, are essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range; combining said modified code signal with said audio signal thereby to provide a composite audio signal.
Claim 34
Dependent Claim 158 words
An audio recording comprising a medium carrying a composite signal which is a mixture of an audio signal and a dynamically modified code signal representing a sequence of code symbols wherein said dynamically modified code signal is obtained by: generating a code signal representing the sequence of symbols with frequency components essentially confined to a preselected signalling band lying within the bandwidth of said audio signal; continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamically filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are, at each time instant, essentially negligibly small outside said signalling band and, at each frequency within said signalling band, are essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range; combining said modified code signal with said audio signal thereby to provide a composite audio signal.
Claim 35
Dependent Claim 198 words
An audio recording comprising a medium carrying a composite signal which is a mixture of an audio signal having a bandwidth in the order of 20 k Hz and a dynamically modified code signal representing a sequence of code symbols wherein said dynamically modified code signal is obtained by: generating a corresponding code signal representing the sequence of code symbols with frequency components essentially confined to a preselected signalling band having a bandwidth of about 8800 Hz centered on a frequency of about 6300 Hz; continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamically filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are, at each time instant, essentially negligibly small outside said signalling band and, at each frequency within said signalling band, are essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range, said preselected proportion representing a modified code signal level which is about 19 dB below the level of said audio signal; combining said modified code signal with said audio signal thereby to provide a composite audio signal.
Claim 36
Dependent Claim 198 words
An audio recording comprising a medium carrying a composite signal which is a mixture of an audio signal having a bandwidth in the order of 20 k Hz and a dynamically modified code signal representing a sequence of code symbols wherein said dynamically modified code signal is obtained by: generating a corresponding code signal representing the sequence of code symbols with frequency components essentially confined to a preselected signalling band having a bandwidth of about 8800 Hz centered on a frequency of about 6300 Hz; continuously frequency analyzing said audio signal over a frequency band encompassing said signalling band; dynamically filtering said code signal as a function of said analysis thereby to provide a modified code signal with frequency component levels which are, at each time instant, essentially negligibly small outside said signalling band and, at each frequency within said signalling band, are essentially a preselected proportion of the levels of the audio signal frequency components in a corresponding frequency range, said preselected proportion representing a modified code signal level which is about 19 dB below the level of said audio signal; combining said modified code signal with said audio signal thereby to provide a composite audio signal.
Claim 37
Dependent Claim 39 words
The recording as set forth in claim 24 wherein said code signal is generated by generating a corresponding pseudorandom number sequence for each symbol input; upsampling and lowpass filtering said sequences; and transposing upwards in frequency the filtered sequence.

References Cited (Backward Citations)

US3004104A Cited
US4395600A Cited
US4425661A Cited
US4593389A Cited
US4775901A Cited
US4903301A Cited
US4965680A Cited
US4979210A Cited
US4777529A Cited
US4943973A Cited
US4972471A Cited
US5212551A Cited

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