US3662342A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Key-controlled electronic security system
Assignee: PHINIZY RB
•
Filing: 1971-02-16
•
Granted: 1972-05-09
•
Expires: 1991-02-16
Abstract
Abstract A key-actuated electronic security system having first and second keys each constituted by a plurality of circuit paths in a pattern of closed and open circuits. The system includes comparing means which electrically compares respective ones of the circuit paths of the keys and which delivers an output signal when there is a predetermined correspondence between respective ones of the circuit paths of the keys. In an embodiment employing a NAND gate, the correspondence is constituted by a complementary relationship and in an embodiment employing Exclusive-OR gates, the correspondence may be constituted by either a complementary or an identical relationship. The system includes means, e.g., a latch, responsive to the output signal for indicating the predetermined correspondence. One of the keys is readily changeable to modify its circuit pattern so that there will not be the predetermined correspondence whereby the changed key will be inoperative to cause the comparing means to deliver an output signal and thus requiring the use of a third key having circuit paths providing a predetermined correspondence with the circuit paths of the changed key in order to cause the comparing means to deliver an output signal. Disclosed also is a key-actuated security system including a plurality of remote stations and a central control station. Each of the remote stations is adapted to provide electrical interconnection with one of the keys. The central station is adapted to receive a plurality of keys, each one of these keys corresponding to one of the remote stations. Key comparing means delivers an output signal when there is a predetermined correspondence between respective ones of the circuit paths of the key received at the remote station and of a particular one of the keys of the first set received at the central control, this output signal being transmitted to the remote station for operating a latch.
Inventors
- 👤 Robert A Hedin
- 👤 Leo J Pantas
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:39
CPC Classifications
G; G07; G07C; G07C9/00; G07C9/00174; G07C9/00658; G07C9/00706; G07C9/00896; G07C9/00904
Claims Analysis
Total Claims: 51
Claim 1
Independent Claim
215 words
A key-actuated electronic security system comprising: a first key constituted by a plurality of circuit paths in a binary code combination of closed and open circuits; a second key constituted by a plurality of circuit paths in a binary code combination of closed and open circuits, individual circuit paths of said second key corresponding to individual respective circuit paths of said first key; means for electrically comparing respective ones of the circuit paths of said first and second keys and operative to deliver an output signal when there is a predetermined correspondence between said respective ones of the circuit paths of said keys; and means responsive to said output signal for indicating said predetermined correspondence between said ones of the circuit paths of said keys; one of said keys being readily changeable thereby when changed to modify the pattern of closed and open circuits thereof so that there will not be said predetermined correspondence whereby said one key will be inoperative to cause the comparing means to deliver an output signal and whereby a third key constituted by a pattern of closed and open circuits providing a predetermined correspondence between the circuit paths thereof and the circuit paths of the changed key must be utilized to cause the comparing means to deliver an output signal.
Claim 2
Dependent Claim
215 words
A key-actuated electronic security system comprising: a first key constituted by a plurality of circuit paths in a binary code combination of closed and open circuits; a second key constituted by a plurality of circuit paths in a binary code combination of closed and open circuits, individual circuit paths of said second key corresponding to individual respective circuit paths of said first key; means for electrically comparing respective ones of the circuit paths of said first and second keys and operative to deliver an output signal when there is a predetermined correspondence between said respective ones of the circuit paths of said keys; and means responsive to said output signal for indicating said predetermined correspondence between said ones of the circuit paths of said keys; one of said keys being readily changeable thereby when changed to modify the pattern of closed and open circuits thereof so that there will not be said predetermined correspondence whereby said one key will be inoperative to cause the comparing means to deliver an output signal and whereby a third key constituted by a pattern of closed and open circuits providing a predetermined correspondence between the circuit paths thereof and the circuit paths of the changed key must be utilized to cause the comparing means to deliver an output signal.
Claim 3
Dependent Claim
153 words
A key-actuated electronic security system comprising: keys each constituted by a plurality of circuit paths in a binary code combination of closed and open circuits, individual circuit paths of one of said keys corresponding to individual respective circuit paths of another of said keys; first means for receiving a first one of said keys and providing electrical interconnection with individual ones of the circuit paths of said first key; second means for receiving a second one of said keys and providing electrical interconnection with individual ones of the circuit paths of said second key; means for electrically comparing respective ones of the circuit paths of said keys and operative to deliver an output signal when there is a predetermined correspondence between said respective ones of the circuit paths of said keys; and means responsive to said output signal for indicating said predetermined correspondence between said ones of the circuit paths of said keys.
Claim 4
Dependent Claim
153 words
A key-actuated electronic security system comprising: keys each constituted by a plurality of circuit paths in a binary code combination of closed and open circuits, individual circuit paths of one of said keys corresponding to individual respective circuit paths of another of said keys; first means for receiving a first one of said keys and providing electrical interconnection with individual ones of the circuit paths of said first key; second means for receiving a second one of said keys and providing electrical interconnection with individual ones of the circuit paths of said second key; means for electrically comparing respective ones of the circuit paths of said keys and operative to deliver an output signal when there is a predetermined correspondence between said respective ones of the circuit paths of said keys; and means responsive to said output signal for indicating said predetermined correspondence between said ones of the circuit paths of said keys.
Claim 5
Dependent Claim
44 words
A system as set forth in claim 2 wherein said means for electrically comparing circuit paths is operative to deliver said output signal when said predetermined correspondence between said respective ones of the circuit paths of said keys is constituted by a complementary relationship.
Claim 6
Dependent Claim
44 words
A system as set forth in claim 2 wherein said means for electrically comparing circuit paths is operative to deliver said output signal when said predetermined correspondence between said respective ones of the circuit paths of said keys is constituted by an identical relationship.
Claim 7
Dependent Claim
29 words
A system as set forth in claim 2 wherein said means responsive to said output signal comprises electrically actuatable lock means for unlocking in response to said output signal.
Claim 8
Dependent Claim
104 words
A system as set forth in claim 2 wherein said means for electrically comparing circuit paths comprises; logic gate means having a plurality of inputs each adapted to be energized by interconnection with an individual closed circuit path of at least one of said keys, said logic gate means delivering an inhibit signal when tHere is other than said predetermined correspondence between said respective ones of the circuit paths of said keys; and an inhibit circuit interconnected with said logic gate means and responsive to said inhibit signal for inhibiting said output signal when said inhibit signal is delivered by said logic gate means.
Claim 9
Dependent Claim
27 words
A system as set forth in claim 6 further comprising an alarm responsive to said inhibit signal for indicating when there is other than said predetermined correspondence.
Claim 10
Dependent Claim
34 words
A system as set forth in claim 6, said logic gate means comprising a NAND gate, said inhibit signal being delivered when less than all of said inputs of said NAND gate are energized.
Claim 11
Dependent Claim
129 words
A system as set forth in claim 6, said logic gate means comprising a plurality of Exclusive-OR gates each having a pair of inputs, one of said pair of inputs being adapted for interconnection with a circuit path of said first key, the other of said pair being adapted for interconnection with a respective circuit path of said second key; and wherein said means for electrically comparing circuit paths also comprises further logic gate means having a plurality of inputs connected with corresponding outputs of said Exclusive-OR gates and having an output terminal providing said inhibit signal, the delivery of said inhibit signal being determined by whether any of the inputs of said further logic gate means is energized by an output signal from one of said Exclusive-OR gates.
Claim 12
Dependent Claim
40 words
A system as set forth in claim 1, wherein said further logic gate means comprises at least one NOR gate whereby said predetermined correspondence between respective ones of the circuit paths of said keys is constituted by an identical relationship.
Claim 13
Dependent Claim
49 words
A system as set forth in claim 10, said means for electrically comparing circuit paths further comprising means for inverting the output signal of each of said Exclusive-OR gates whereby said predetermined correspondence between respective ones of the circuit paths of said keys is constituted by a complementary relationship.
Claim 14
Dependent Claim
25 words
A system as set forth in claim 6, said keys each having a common conductor electrically connecting in common the closed circuits of the key.
Claim 15
Dependent Claim
28 words
A system as set forth in claim 6, each of said first and second means for receiving keys including means for applying a voltage to the common conductor.
Claim 16
Dependent Claim
50 words
A system as set forth in claim 13 wherein said means for electrically comparing circuit paths further comprises a matrix interconnected with the first and second key-receiving means and said logic gate means for connecting respective ones of the circuit paths of said keys with respective ones of said inputs.
Claim 17
Dependent Claim
129 words
A system as set forth in claim 14 wherein one of the means for applying a voltage to a common conductor is adapted to apply a voltage higher than that of the other of the voltage applying means for applying a voltage to a common conductor, said system further comprising a voltage threshold detector interconnected with said other of the voltage applying means and which is operative to sense the voltage on the common conductor to which voltage is applied by said other voltage applying means and to deliver a further inhibit signal to said inhibit circuit thereby to cause inhibiting of said output signal if the sensed voltage exceeds a threshold value less than said higher voltage but greater than that applied by said other voltage applying means.
Claim 18
Dependent Claim
242 words
A key-actuated electronic security system comprising: first and second keys each constituted by a plurality of circuit paths in a binary code combination of closed and open circuits, individual circuit paths of said second key corresponding to individual respective circuit paths of said first key; means for electrically comparing respective ones of the circuit paths of said keys, comprising: means responsive to at least one closed circuit path of one of said keys for providing a control signal; a NAND gate having a plurality of inputS each adapted to be energized by interconnection with individual ones of said circuit paths; an inhibit circuit interconnected with said means for providing a control signal and with the output of said NAND gate, said inhibit circuit being responsive to an output signal from said NAND gate for inhibiting said control signal; and means for interconnecting individual ones of the circuit paths of said keys with the inputs of said NAND gate to cause said NAND gate output signal to be absent when there is a predetermined correspondence between respective ones of the circuit paths of said keys and to be present when there is other than said predetermined correspondence, whereby when said NAND gate output signal is absent, said control signal is not inhibited; and electrically actuatable lock means for unlocking in response to said control signal when said control signal is not inhibited, whereby said unlocking occurs only when there is said predetermined correspondence.
Claim 19
Dependent Claim
242 words
A key-actuated electronic security system comprising: first and second keys each constituted by a plurality of circuit paths in a binary code combination of closed and open circuits, individual circuit paths of said second key corresponding to individual respective circuit paths of said first key; means for electrically comparing respective ones of the circuit paths of said keys, comprising: means responsive to at least one closed circuit path of one of said keys for providing a control signal; a NAND gate having a plurality of inputS each adapted to be energized by interconnection with individual ones of said circuit paths; an inhibit circuit interconnected with said means for providing a control signal and with the output of said NAND gate, said inhibit circuit being responsive to an output signal from said NAND gate for inhibiting said control signal; and means for interconnecting individual ones of the circuit paths of said keys with the inputs of said NAND gate to cause said NAND gate output signal to be absent when there is a predetermined correspondence between respective ones of the circuit paths of said keys and to be present when there is other than said predetermined correspondence, whereby when said NAND gate output signal is absent, said control signal is not inhibited; and electrically actuatable lock means for unlocking in response to said control signal when said control signal is not inhibited, whereby said unlocking occurs only when there is said predetermined correspondence.
Claim 20
Dependent Claim
248 words
A key-actuated electronic security system comprising: first and second keys each constituted by a plurality of circuit paths in a pattern of closed and open circuits; means for electrically comparing respective ones of the circuit paths of said keys, comprising: means responsive to at least one closed circuit path of one of said keys for providing a control signal; a plurality of Exclusive-OR gates each having a pair of inputs each of which is adapted to be energized by respective ones of the circuit paths of said keys; a NOR gate having a plurality of inputs interconnected with respective ones of the outputs of said Exclusive-OR gates; an inhibit circuit interconnected with said means for providing a control signal and with the output of said NOR gate, said inhibit circuit being responsive to an output signal from said NOR gate for inhibiting said control signal; and means for interconnecting individual ones of the circuit paths of said keys with the inputs to said Exclusive-OR gates to cause said NOR gate output signal to be present when there is a predetermined correspondence between respective ones of the circuit paths of said keys and to be absent when there is other than predetermined correspondence, whereby when said NOR gate output signal is present, said control signal is not inhibited; and electrically actuatable lock means for unlocking in response to said control signal when said control signal is not inhibited, whereby said unlocking occurs only when there is said predetermined correspondence.
Claim 21
Dependent Claim
248 words
A key-actuated electronic security system comprising: first and second keys each constituted by a plurality of circuit paths in a pattern of closed and open circuits; means for electrically comparing respective ones of the circuit paths of said keys, comprising: means responsive to at least one closed circuit path of one of said keys for providing a control signal; a plurality of Exclusive-OR gates each having a pair of inputs each of which is adapted to be energized by respective ones of the circuit paths of said keys; a NOR gate having a plurality of inputs interconnected with respective ones of the outputs of said Exclusive-OR gates; an inhibit circuit interconnected with said means for providing a control signal and with the output of said NOR gate, said inhibit circuit being responsive to an output signal from said NOR gate for inhibiting said control signal; and means for interconnecting individual ones of the circuit paths of said keys with the inputs to said Exclusive-OR gates to cause said NOR gate output signal to be present when there is a predetermined correspondence between respective ones of the circuit paths of said keys and to be absent when there is other than predetermined correspondence, whereby when said NOR gate output signal is present, said control signal is not inhibited; and electrically actuatable lock means for unlocking in response to said control signal when said control signal is not inhibited, whereby said unlocking occurs only when there is said predetermined correspondence.
Claim 22
Dependent Claim
196 words
A key-actuated security system comprising: a plurality of remote stations each adapted to provide electrical interconnection with a key constituted by a plurality of circuit paths in a pattern of closed and open circuits; and a central control station interconnected with said remote stations, said control station adapted to provide electrical interconnection with a plurality of keys each constituted by a plurality of circuit paths in a pattern of closed and open circuits, there being one of said plurality of keys for each of said remote stations, at least some of said plurality of keys having arrangements of circuit paths which arrangements are different from each other, said control station comprising: means for comparing circuit paths of successive ones of the individual keys interconnected at remote stations with respective circuit paths of corresponding ones of said plurality of keys and operative to deliver an output signal when there is a predetermined correspondence between respective ones of the circuit paths compared; and means for transmitting said output signal to one of said remote stations where a key provides said predetermined correspondence; said remote stations each including means responsive to said output signal for indicating said predetermined correspondence.
Claim 23
Dependent Claim
196 words
A key-actuated security system comprising: a plurality of remote stations each adapted to provide electrical interconnection with a key constituted by a plurality of circuit paths in a pattern of closed and open circuits; and a central control station interconnected with said remote stations, said control station adapted to provide electrical interconnection with a plurality of keys each constituted by a plurality of circuit paths in a pattern of closed and open circuits, there being one of said plurality of keys for each of said remote stations, at least some of said plurality of keys having arrangements of circuit paths which arrangements are different from each other, said control station comprising: means for comparing circuit paths of successive ones of the individual keys interconnected at remote stations with respective circuit paths of corresponding ones of said plurality of keys and operative to deliver an output signal when there is a predetermined correspondence between respective ones of the circuit paths compared; and means for transmitting said output signal to one of said remote stations where a key provides said predetermined correspondence; said remote stations each including means responsive to said output signal for indicating said predetermined correspondence.
Claim 24
Dependent Claim
162 words
A key-actuated security system comprising: a plurality of remote stations each adaptEd to provide electrical interconnection with a key constituted by a plurality of circuit paths in a pattern of closed and open circuits; and a central control station interconnected with said remote stations, said control station adapted to provide electrical interconnection with a plurality of keys each constituted by a plurality of circuit paths in a pattern of closed and open circuits, there being one of said plurality of keys for each of said remote stations, at least some of said plurality of keys having arrangements of circuit paths which arrangements are different from each other; means for comparing circuit paths of keys interconnected at remote stations with respective circuit paths of corresponding ones of said plurality of keys and operative to determine when there is a predetermined correspondence between respective ones of the circuit paths compared; and means responsive to operation of the comparing means for indicating said predetermined correspondence.
Claim 25
Dependent Claim
162 words
A key-actuated security system comprising: a plurality of remote stations each adaptEd to provide electrical interconnection with a key constituted by a plurality of circuit paths in a pattern of closed and open circuits; and a central control station interconnected with said remote stations, said control station adapted to provide electrical interconnection with a plurality of keys each constituted by a plurality of circuit paths in a pattern of closed and open circuits, there being one of said plurality of keys for each of said remote stations, at least some of said plurality of keys having arrangements of circuit paths which arrangements are different from each other; means for comparing circuit paths of keys interconnected at remote stations with respective circuit paths of corresponding ones of said plurality of keys and operative to determine when there is a predetermined correspondence between respective ones of the circuit paths compared; and means responsive to operation of the comparing means for indicating said predetermined correspondence.
Claim 26
Dependent Claim
258 words
A key-actuated security system comprising: a plurality of remote stations each adapted to provide electrical interconnection with a key constituted by a plurality of circuit paths in a pattern of closed and open circuits; and a central control station interconnected with said remote stations, said control station adapted to provide electrical interconnection with a plurality of keys each constituted by a plurality of circuit paths in a pattern of closed and open circuits, there being one of said plurality of keys for each of said remote stations, at least some of said plurality of keys having arrangements of circuit paths which arrangements are different from each other, said control station comprising: means interconnected with each of said remote stations and responsive to interconnection of an individual key at a respective one of said remote stations for providing a first control signal; means interconnected with each of said remote stations for comparing circuit paths of individual keys interconnected at remote stations with respective circuit paths of corresponding ones of said plurality of keys, including first logic gate means operative to provide a second control signal when there is a predetermined correspondence between respective ones of the circuit paths compared; further logic gate means responsive to said first and second control signals for delivering an output signal when said control signals are concurrently present; and means for transmitting said output signal to one of said remote stations where a key provides said predetermined correspondence; said remote stations each including means responsive to said output signal for indicating said predetermined correspondence.
Claim 27
Dependent Claim
258 words
A key-actuated security system comprising: a plurality of remote stations each adapted to provide electrical interconnection with a key constituted by a plurality of circuit paths in a pattern of closed and open circuits; and a central control station interconnected with said remote stations, said control station adapted to provide electrical interconnection with a plurality of keys each constituted by a plurality of circuit paths in a pattern of closed and open circuits, there being one of said plurality of keys for each of said remote stations, at least some of said plurality of keys having arrangements of circuit paths which arrangements are different from each other, said control station comprising: means interconnected with each of said remote stations and responsive to interconnection of an individual key at a respective one of said remote stations for providing a first control signal; means interconnected with each of said remote stations for comparing circuit paths of individual keys interconnected at remote stations with respective circuit paths of corresponding ones of said plurality of keys, including first logic gate means operative to provide a second control signal when there is a predetermined correspondence between respective ones of the circuit paths compared; further logic gate means responsive to said first and second control signals for delivering an output signal when said control signals are concurrently present; and means for transmitting said output signal to one of said remote stations where a key provides said predetermined correspondence; said remote stations each including means responsive to said output signal for indicating said predetermined correspondence.
Claim 28
Dependent Claim
42 words
A key-actuated security system as set forth in claim 20 wherein said first logic gate means includes input terminals adapted to be supplied with input signals when there is other than said predetermined correspondence between respective ones of the circuit paths compared.
Claim 29
Dependent Claim
86 words
A key-actuated security system as set forth in claim 21 wherein said first logic gate means comprises a plurality of logic gates each corresponding to one of the remote stations and each providing an output signal when respective circuit paths compared are each closed circuits, and a further logic gate having input terminals interconnected with the output terminals of said plurality of logic gates and providing an output signal constituting said second control signal unless one of said plurality of logic gates provides an output signal.
Claim 30
Dependent Claim
35 words
A key-actuated security system as set forth in claim 22 wherein said plurality of logic gates are constituted by a plurality of AND gates and said further logic gate is constituted by a NOR gate.
Claim 31
Dependent Claim
102 words
A key-actuated security system as set forth in claim 21 wherein said predetermined correspondence is constituted by an identical relationship between respective ones of the key circuit paths compared and wherein said first logic gate means Comprises a plurality of logic gates each providing an output signal when respective circuit paths compared are respectively constituted by a closed and open circuit, and a further logic gate having input terminals interconnected with the output terminals of said plurality of logic gates and providing an output signal constituting said second control signal unless one of said plurality of logic gates provides an output signal.
Claim 32
Dependent Claim
35 words
A key-actuated security system as set forth in claim 24 wherein said plurality of logic gates are constituted by a plurality of Exclusive-OR gates and said further logic gate is constituted by a NOR gate.
Claim 33
Dependent Claim
51 words
A key-actuated security system as set forth in claim 21, said system including a plurality of circuit leads connecting each of said remote stations in common with said means for comparing circuit paths, there being one of said leads for each circuit path of a key interconnected at a remote station.
Claim 34
Dependent Claim
39 words
A key-actuated security system as set forth in claim 26 further comprising means for connecting each of said leads in a circuit, including a respective isolation diode, with a respective circuit path of each of said plurality of keys.
Claim 35
Dependent Claim
59 words
A key-actuated security system as set forth in claim 26 wherein said means for comparing circuit means includes means for counting the closed circuits of respective individual keys interconnected at remote stations and operative to inhibit said first control signal if the number of closed circuits of an individual key is less than a constrained number of closed circuits.
Claim 36
Dependent Claim
36 words
A key-actuated security system as set forth in claim 28 wherein said means for counting comprises a digital-to-analog converter having an output terminal interconnected with one of the input terminals of said first logic gate means.
Claim 37
Dependent Claim
48 words
A key-actuated security system as set forth in claim 26 further comprising means for sequentially interrogating said remote stations to cause connection of circuit paths of keys at said remote stations to said leads, said plurality of logic gates each being responsive to operation of the interrogation means.
Claim 38
Dependent Claim
29 words
A key-actuated security system as set forth in claim 20 wherein each of said remote station comprises a key receptacle including contacts for providing said interconnection with a key.
Claim 39
Dependent Claim
30 words
A key-actuated security system as set forth in claim 20 wherein said means responsive to said output signal comprises an electric latch, operation of which thereby indicates said predetermined correspondence.
Claim 40
Dependent Claim
34 words
A key-actuated security system as set forth in claim 20 wherein said control station further comprises alarm means for signalling when a key interconnected at a remote station fails to provide said predetermined correspondence.
Claim 41
Dependent Claim
225 words
A key-actuated security system comprising: a plurality of remote stations each adapted to provide electrical interconnection with a key constituted by a plurality of circuit paths in a pattern of closed and open circuits; and a central control station interconnected with said remote stations, said control station adapted to provide electrical interconnection with a plurality of keys each constituted by a plurality of circuit paths in a pattern of closed and open circuits, there being one of said plurality of keys for each of said remote stations, at least some of said plurality of keys having arrangements of circuit paths which arrangements are different from each other, said control station comprising: means for sequentially interrogating said remote stations; means interconnected with each of said remote stations for comparing circuit paths of individual keys interconnected at remote stations respectively interrogated with respective circuit paths of corresponding ones of said plurality of keys and operative to deliver an output signal when there is a predetermined correspondence between respective ones of the circuit paths compared; means for transmitting said output signal to one of said remote statioNs where a key provides said predetermined correspondence; said remote stations each including means responsive to interconnection of a key at the respective remote station and to said output signal when the respective remote station is interrogated for indicating said predetermined correspondence.
Claim 42
Dependent Claim
225 words
A key-actuated security system comprising: a plurality of remote stations each adapted to provide electrical interconnection with a key constituted by a plurality of circuit paths in a pattern of closed and open circuits; and a central control station interconnected with said remote stations, said control station adapted to provide electrical interconnection with a plurality of keys each constituted by a plurality of circuit paths in a pattern of closed and open circuits, there being one of said plurality of keys for each of said remote stations, at least some of said plurality of keys having arrangements of circuit paths which arrangements are different from each other, said control station comprising: means for sequentially interrogating said remote stations; means interconnected with each of said remote stations for comparing circuit paths of individual keys interconnected at remote stations respectively interrogated with respective circuit paths of corresponding ones of said plurality of keys and operative to deliver an output signal when there is a predetermined correspondence between respective ones of the circuit paths compared; means for transmitting said output signal to one of said remote statioNs where a key provides said predetermined correspondence; said remote stations each including means responsive to interconnection of a key at the respective remote station and to said output signal when the respective remote station is interrogated for indicating said predetermined correspondence.
Claim 43
Dependent Claim
46 words
A key-actuated security system as set forth in claim 34 wherein the interrogation means includes an interrogation code generator, each of said remote stations and said central station including a decoder operative in response to the interrogation code to determine which respective remote station is interrogated.
Claim 44
Dependent Claim
47 words
A key-actuated security system as set forth in claim 35 wherein said interrogation code generator comprises a counter, said system including an oscillator for advancing the count of said counter, said decoders each comprising a plurality of logic gate means responsive to the count of said counter.
Claim 45
Dependent Claim
54 words
A key-actuated security system as set forth in claim 36 wherein said counter comprises a binary ripple counter having a plurality of binary stages, the logic gate means of each of said decoders being constituted by a plurality of logic AND gates whose input terminals are connected with respective ones of the binary stages.
Claim 46
Dependent Claim
50 words
A key-actuated security system as set forth in claim 35 including a first plurality of circuit leads connecting each of said remote stations in common with said means for comparing circuit paths, there being one of said leads for each circuit path of a key interconnected at a remote station.
Claim 47
Dependent Claim
29 words
A key-actuated security system as set forth in claim 38 including a further plurality of circuit leads connecting decoders of said remote stations in common with said code generator.
Claim 48
Dependent Claim
65 words
A key-actuated security system as set forth in claim 38 including means for transmitting the interrogation code over said leads to each of the remote stations, the remote stations each comprising means, including a time delay circuit, for connecting the circuit paths of a key interconnected at the remote station with respective ones of said leads in response to interrogation of the respective remote station.
Claim 49
Dependent Claim
19 words
A key-actuated security system as set forth in claim 40 wherein said time delay circuit comprises a one-shot multivibrator.
Claim 50
Dependent Claim
283 words
A key-actuated security system comprising: a plurality of remote stations each adapted to provide electrical interconnection with a key constituted by a plurality of circuit paths in a pattern of closed and open circuits; and a central control station interconnected with said remote stations, said control station adapted to provide electrical interconnection with a plurality of keys each constituted by a plurality of circuit paths in a pattern of closed and open circuits, there being one of said plurality of keys for each of said remote stations, at least some of said plurality of keys having arrangements of circuit paths which arrangements are different from each other, said control station comprising; means for sequentially interrogating said remote stations; means interconnected with each of said remote stations and responsive to interconnection of an individual key at a respective one of said remote stations for providing a first control signal; means interconnected with each of said remote stations for comparing circuit paths of individual keys interconnected at remote stations with respective circuit paths of corresponding ones of said plurality of keys, including first logic gate means operative to provide a second control signal when there is a predetermined correspondence between respective ones of the circuit paths compared; further logic gate means responsive to said first and second control signals for delivering an output signal when said control signals are concurrently present; and means for transmitting said output signal to one of said remote stations where a key provides said predetermined correspondence; said remote stations each including meAns responsive to interconnection of a key at the respective remote station and to said output signal when the respective remote station is interrogated for indicating said predetermined correspondence.
Claim 51
Dependent Claim
283 words
A key-actuated security system comprising: a plurality of remote stations each adapted to provide electrical interconnection with a key constituted by a plurality of circuit paths in a pattern of closed and open circuits; and a central control station interconnected with said remote stations, said control station adapted to provide electrical interconnection with a plurality of keys each constituted by a plurality of circuit paths in a pattern of closed and open circuits, there being one of said plurality of keys for each of said remote stations, at least some of said plurality of keys having arrangements of circuit paths which arrangements are different from each other, said control station comprising; means for sequentially interrogating said remote stations; means interconnected with each of said remote stations and responsive to interconnection of an individual key at a respective one of said remote stations for providing a first control signal; means interconnected with each of said remote stations for comparing circuit paths of individual keys interconnected at remote stations with respective circuit paths of corresponding ones of said plurality of keys, including first logic gate means operative to provide a second control signal when there is a predetermined correspondence between respective ones of the circuit paths compared; further logic gate means responsive to said first and second control signals for delivering an output signal when said control signals are concurrently present; and means for transmitting said output signal to one of said remote stations where a key provides said predetermined correspondence; said remote stations each including meAns responsive to interconnection of a key at the respective remote station and to said output signal when the respective remote station is interrogated for indicating said predetermined correspondence.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-05-09 | 1975-11-08 | 1976-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-05-09 | 1979-11-08 | 1980-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-05-09 | 1983-11-08 | 1984-05-09 | $7700.00 | Window Closed / Lapsed |