Patent US4419933A successfully refreshed from Google Patents.
US4419933A
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Apparatus and method for selectively activating plural electrical loads at predetermined relative times
Assignee: Orica Explosives Technology Pty Ltd
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Filing: 1981-10-01
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Granted: 1983-12-13
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Expires: 2001-10-01
Abstract
Abstract Separate electrical timing and load activation devices are provided for each of plural electrical loads and each device is connected to receive reference timing signals from a central unit. Each of the separate timing and load activation devices measures a reference time interval accurately defined by the reference timing signals and subsequently activates its associated electrical load after a respectively corresponding predetermined time delay which is determined as a function of the locally measured reference time interval.
Inventors
- 👤 Ian J. Kirby
- 👤 Michael I. Mitchell
- 👤 Andrew Stratton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 19:20
CPC Classifications
H; H03; H03K; H03K5/00; H03K5/13; H03K5/131; F; F42; F42B; F42B3/00; F42B3/10; F42B3/12; F42B3/121; F42B3/122; F42D; F42D1/00; F42D1/04; F42D1/045; F42D1/05; F42D1/055; G; G01; G01V; G01V1/00; G01V1/02; G01V1/04; G01V1/06; G01V1/08; G04; G04F; G04F1/00; G04F1/005
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
167 words
A system for energizing a series of electrical loads in predetermined timed sequence after a starting signal, which system comprises: a supply of electrical energy, means to generate a train of accurately timed control signals, and a time control switching circuit for each load for connecting said supply to the corresponding load at a desired time, each of said switching circuits comprising: means to receive said train of control signals, a preset signal selecting system having means to select a first and a second of said control signals and to generate first and second timing signals in response to said first and second control signals respectively, means to generate a starting signal, and timing means to measure the interval between said first and second timing signals by counting locally generated timing pulses and to generate an output signal whereby the corresponding load is connected to an energy supply at a time interval after the starting signal determined by the interval between the first and second timing signals.
Claim 2
Independent Claim
167 words
A system for energizing a series of electrical loads in predetermined timed sequence after a starting signal, which system comprises: a supply of electrical energy, means to generate a train of accurately timed control signals, and a time control switching circuit for each load for connecting said supply to the corresponding load at a desired time, each of said switching circuits comprising: means to receive said train of control signals, a preset signal selecting system having means to select a first and a second of said control signals and to generate first and second timing signals in response to said first and second control signals respectively, means to generate a starting signal, and timing means to measure the interval between said first and second timing signals by counting locally generated timing pulses and to generate an output signal whereby the corresponding load is connected to an energy supply at a time interval after the starting signal determined by the interval between the first and second timing signals.
Claim 3
Dependent Claim
32 words
A system as in claim 1 wherein each load is an electric fusehead and each time control switching circuit is located with a corresponding fusehead in a detonator casing containing explosive charges.
Claim 4
Dependent Claim
41 words
A system as in claim 2 including an energy storage capacitor in each casing to store sufficient energy to operate the switching circuit and fire the fusehead even if the external connections to the fusehead are disconnected after the starting signal.
Claim 5
Dependent Claim
44 words
A system as in claim 1 including in each time control switching circuit signal discriminator means to identify duration of frequency characteristics of the control signals whereby only signals having selected duration or frequency characteristics will be passed for use by the switching circuit.
Claim 6
Dependent Claim
47 words
A system as in claim 1 wherein each time control switching circuit includes: means to separate or derive control signals from the energy supply, means to preset the correct starting conditions for the switching circuit, and means to protect the switching circuit from damage by excess voltage.
Claim 7
Dependent Claim
49 words
A system as in claim 1 wherein said preset signal selecting system comprises: an electronic digital counter having logic elements whereby the state of the logic elements represents the count of control signals and the first and second timing signals are generated by the attainment of predetermined logic states.
Claim 8
Dependent Claim
64 words
A system as in claim 6 wherein said logic elements comprises: a first set of logic gates connected to said digital counter and which, on the count of the first predetermined number, generates the first timing signal, and a second set of logic gates connected to said digital counter and which, on the count of the second predetermined number, generates the second timing signal.
Claim 9
Dependent Claim
94 words
A system as in claim 6 wherein said logic elements comprise: a first logic register having said first predetermined number premanently set thereinto, and a first logic comparator for comparing the contents of the counter compared with the state of the first logic register thereby generating a first timing signal when the counter contents and the state of the first logic register are identical, a second register having said second predetermined number permanently set thereinto, and a second logic comparator which generates the second timing signal at the count of the second predetermined number.
Claim 10
Dependent Claim
36 words
A system as in claim 1 wherein each of said timing means comprises: a clock pulse generator containing an oscillator, and a reversible electronic digital counter connected to receive clock pulses from said clock pulse generator.
Claim 11
Dependent Claim
64 words
A system as in claim 9 wherein the signal selecting system and reversible counter operate in response to the first selected control signal to feed the first timing signal to the reversible counter which then starts a count of clock pulses in one direction and, in response to the second selected control signal to feed the second timing signal to stop the reversible counter.
Claim 12
Dependent Claim
17 words
A system as in claim 1 wherein the second timing signal generates a substantially coincident starting signal.
Claim 13
Dependent Claim
39 words
A system as in claim 1 wherein the second timing signal starts a delay counter which counts a predetermined number of control signals after the control signal which generates the second timing signal and thereupon generates the starting signal.
Claim 14
Dependent Claim
43 words
A system as in claim 10 wherein said starting signal initiates a reverse count of clock pulses on the reversible counter and, when the reverse count returns to the starting count, an energizing signal is produced which causes the load to be energized.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-12-12 | 1987-06-13 | 1987-12-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-12-12 | 1991-06-13 | 1991-12-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-12-12 | 1995-06-13 | 1995-12-13 | $7700.00 | Window Closed / Lapsed |