US4100490A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Elapsed time indicator and electrolytic timer cell
Assignee: Diametrics Inc
•
Filing: 1977-03-11
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Granted: 1978-07-11
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Expires: 1997-03-11
Abstract
Abstract An elapsed time indicator includes an electrolytic timing cell in series connection with a resistor, which series circuit may be connected to a D.C. voltage. The cell is comprised of an aluminum can containing a liquid electrolyte with an aluminum anode immersed therein. During operation an aluminum oxide film is grown on the surfaces of the anode, the film thickness and resistance increasing with time. The voltage dropped across the cell of any instant is employed as an indication of the accumulated elapsed time during which the D.C. voltage has been connected to the circuit.
Inventors
- 👤 David B. Peck
- 👤 Vincent T. Guntlow
- 👤 Paul H. Netherwood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 08:29
CPC Classifications
G; G04; G04F; G04F10/00; G04F10/10
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
56 words
An elapsed time indicating cell comprising a valve-metal anode; a cathode being separated from said anode by a space; an electrolyte occupying said space; a housing containing said electrolyte; and an anodically formed oxide film overlying the surface of said anode, said film having a thickness corresponding to a formation voltage of less than 3 volts.
Claim 2
Dependent Claim
56 words
An elapsed time indicating cell comprising a valve-metal anode; a cathode being separated from said anode by a space; an electrolyte occupying said space; a housing containing said electrolyte; and an anodically formed oxide film overlying the surface of said anode, said film having a thickness corresponding to a formation voltage of less than 3 volts.
Claim 3
Dependent Claim
14 words
The cell of claim 1 wherein said corresponding formation voltage is about 2 volts.
Claim 4
Dependent Claim
16 words
The cell of claim 1 wherein said housing is a metal container serving as said cathode.
Claim 5
Dependent Claim
10 words
The cell of claim 1 wherein said anode is aluminum.
Claim 6
Dependent Claim
16 words
The cell of claim 1 wherein said cathode is aluminum and said electrolyte contains borate ions.
Claim 7
Dependent Claim
16 words
The cell of claim 1 wherein said anode is in the form of a coiled wire.
Claim 8
Dependent Claim
121 words
An elapsed time indicator comprising: (a) an indicating cell comprising a valve metal anode, a cathode being separated from said anode by a space, an electrolyte occupying said space, an oxide film of said valve metal overlying the surface of said anode, said film having a thickness corresponding to a formation voltage of less than 3 volts, and a housing containing said electrolyte; (b) a resistor having a series electrical circuit connection with said cell; (c) two power supply terminals terminating said series circuit; (d) a voltage sensing means for sensing the voltage across said cell and for producing a signal that is a function of the total time during which a D.C. power supply has been connected to said terminals.
Claim 9
Dependent Claim
121 words
An elapsed time indicator comprising: (a) an indicating cell comprising a valve metal anode, a cathode being separated from said anode by a space, an electrolyte occupying said space, an oxide film of said valve metal overlying the surface of said anode, said film having a thickness corresponding to a formation voltage of less than 3 volts, and a housing containing said electrolyte; (b) a resistor having a series electrical circuit connection with said cell; (c) two power supply terminals terminating said series circuit; (d) a voltage sensing means for sensing the voltage across said cell and for producing a signal that is a function of the total time during which a D.C. power supply has been connected to said terminals.
Claim 10
Dependent Claim
16 words
The indicator of claim 7 wherein said housing is a metal container serving as said cathode.
Claim 11
Dependent Claim
11 words
The indicator of claim 7 wherein said anode is of aluminum.
Claim 12
Dependent Claim
17 words
The indicator of claim 9 wherein said cathode is of aluminum and said electrolyte contains borate ions.
Claim 13
Dependent Claim
14 words
The indicator of claim 7 wherein said corresponding formation voltage is about 2 volts.
Claim 14
Dependent Claim
16 words
The indicator of claim 7 wherein said anode is in the form of a coiled wire.
Claim 15
Dependent Claim
19 words
The indicator of claim 7 wherein said sensing means is an electronic circuit which includes a Schmitt trigger circuit.
Claim 16
Dependent Claim
25 words
The indicator of claim 13 wherein a Schmitt trigger circuit is connected to a lamp, the illumination of said lamp serving as said alarm signal.
Claim 17
Dependent Claim
20 words
The indicator of claim 7 wherein said sensing means is a lamp being directly connected in parallel with said cell.
Claim 18
Dependent Claim
22 words
The indicator of claim 7 wherein said sensing means is a voltmeter for continuously indicating the elapsed operating time of said system.
Claim 19
Dependent Claim
10 words
The cell of claim 1 wherein said thickness is zero.
Claim 20
Dependent Claim
10 words
The indicator of claim 7 wherein said thickness is zero.
Claim 21
Dependent Claim
121 words
An elapsed time indicator comprising: (a) an indicating cell comprising a valve metal anode, a cathode being separated from said anode by a space, an electrolyte occupying said space, an oxide film of said valve metal overlying the surface of said anode, said film having a thickness corresponding to a formation voltage of less than 3 volts, and a housing containing said electrolyte; (b) a resistor having a series electrical circuit connection with said cell; (c) two power supply terminals terminating said series circuit; (d) a capacitance sensing means for sensing the capacitance of said cell and for producing a signal that is a function of the total time during which a D.C. power supply has been connected to said terminals.
Claim 22
Dependent Claim
121 words
An elapsed time indicator comprising: (a) an indicating cell comprising a valve metal anode, a cathode being separated from said anode by a space, an electrolyte occupying said space, an oxide film of said valve metal overlying the surface of said anode, said film having a thickness corresponding to a formation voltage of less than 3 volts, and a housing containing said electrolyte; (b) a resistor having a series electrical circuit connection with said cell; (c) two power supply terminals terminating said series circuit; (d) a capacitance sensing means for sensing the capacitance of said cell and for producing a signal that is a function of the total time during which a D.C. power supply has been connected to said terminals.
Claim 23
Dependent Claim
18 words
The cell of claim 1 wherein said valve-metal anode consists of a film having been metallized with aluminum.
Claim 24
Dependent Claim
13 words
The cell of claim 21 wherein said film is made of polyethylene terephthalate.
References Cited (Backward Citations)
US3355731A
Cited
US3387288A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-07-10 | 1982-01-09 | 1982-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-07-10 | 1986-01-09 | 1986-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-07-10 | 1990-01-09 | 1990-07-11 | $7700.00 | Window Closed / Lapsed |