US4013922A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sunlamp device
Assignee: US Philips Corp
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Filing: 1975-07-10
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Granted: 1977-03-22
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Expires: 1995-07-10
Abstract
Abstract The invention relates to a sunlamp device which is provided with a high pressure mercury vapour discharge tube and with an auxiliary device for extinguishing the discharge tube with a given time delay on termination of the desired irradiation period. According to the invention a switch connected in series with the discharge tube is shunted by a resistor having a positive temperature coefficient of resistance (PTC resistor). This ensures that after the switch has been opened on termination of the desired irradiation period the PTC resistor passes current for some time. As a result the resistance of this PTC resistor is increased, which causes the current through the discharge tube to be reduced. This finally results in an increase of the operating voltage of the discharge tube to a value higher than the available voltage, so that the tube is extinguished. This device is simpler than a known device provided with two timers.
Inventors
- 👤 Andries VAN DER Meulen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 18:52
CPC Classifications
A; A61; A61N; A61N5/00; A61N5/06; A61N5/0613; A61N5/0614; A61N2005/065; A61N2005/0655
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
162 words
A Sunlamp device comprising two input terminals for supplying an electric current to the device, a high pressure mercury vapour discharge tube provided with two main electrodes, a switch having a first position for setting the discharge tube into operation, means connecting the discharge tube and the switch in series circuit across the input terminals, a resistor having a positive temperature coefficient of resistance thereby to extinguish the discharge tube with a time delay on termination of a desired irradiation period, said resistor of positive temperature coefficient of resistance being connected in circuit so that in the first position of the switch it carries substantially no current and in a second position of said switch said resistor is in series with the discharge tube across the input terminals of the device, and means for preventing the discharge tube from restriking after extinction thereof by maintaining the voltage between the main electrodes of the discharge tube at a low voltage different from zero.
Claim 2
Dependent Claim
162 words
A Sunlamp device comprising two input terminals for supplying an electric current to the device, a high pressure mercury vapour discharge tube provided with two main electrodes, a switch having a first position for setting the discharge tube into operation, means connecting the discharge tube and the switch in series circuit across the input terminals, a resistor having a positive temperature coefficient of resistance thereby to extinguish the discharge tube with a time delay on termination of a desired irradiation period, said resistor of positive temperature coefficient of resistance being connected in circuit so that in the first position of the switch it carries substantially no current and in a second position of said switch said resistor is in series with the discharge tube across the input terminals of the device, and means for preventing the discharge tube from restriking after extinction thereof by maintaining the voltage between the main electrodes of the discharge tube at a low voltage different from zero.
Claim 3
Dependent Claim
78 words
A device as claimed in claim 1 wherein the switch is shunted by the resistor of positive temperature coefficient of resistance, means coupling the switch to a second switch so that the two switches are simultaneously opened and closed, the discharge tube being provided with a starting electrode connected to the second switch so that in the open position of the second switch the starting electrode is switched out of circuit thereby preventing restriking of the discharge tube.
Claim 4
Dependent Claim
39 words
A device as claimed in claim 1 further comprising a timer, the first switch being operated by said timer which on termination of the desired irradiation period changes over the switch from the first position to the second position.
Claim 5
Dependent Claim
37 words
A device as claimed in claim 3, characterized in that the first switch is provided with a gong which, on this switch being changed over from the first position to the second position, is set into vibration.
Claim 6
Dependent Claim
164 words
An irradiation apparatus comprising, a pair of input terminals for supplying an AC voltage to the apparatus, an electric discharge tube, a switch having a first operative position for energizing the discharge tube and a second position, an impedance element, means connecting the tube, the switch and the impedance element in a series circuit across the input terminals, a PTC resistor, means connecting the PTC resistor in circuit so that in the first position of said switch the PTC resistor carries substantially zero current and in the second position of the switch the PTC resistor is in series with the discharge tube across the input terminals so that a heating current flows in said PTC resistor that decreases as the resistor heats up thereby to provide a time delayed extinction of the discharge tube, said switch being switched from the first to the second position at the end of a desired irradiation period, and means coupled to the discharge tube for preventing reignition thereof.
Claim 7
Dependent Claim
164 words
An irradiation apparatus comprising, a pair of input terminals for supplying an AC voltage to the apparatus, an electric discharge tube, a switch having a first operative position for energizing the discharge tube and a second position, an impedance element, means connecting the tube, the switch and the impedance element in a series circuit across the input terminals, a PTC resistor, means connecting the PTC resistor in circuit so that in the first position of said switch the PTC resistor carries substantially zero current and in the second position of the switch the PTC resistor is in series with the discharge tube across the input terminals so that a heating current flows in said PTC resistor that decreases as the resistor heats up thereby to provide a time delayed extinction of the discharge tube, said switch being switched from the first to the second position at the end of a desired irradiation period, and means coupled to the discharge tube for preventing reignition thereof.
Claim 8
Dependent Claim
24 words
An irradiation apparatus as claimed in claim 5 wherein the first circuit connecting means connects the PTC resistor in parallel with the first switch.
Claim 9
Dependent Claim
59 words
An irradiation apparatus as claimed in claim 5 wherein said reignition preventing means comprises voltage divider means including the PTC resistor and the first impedance element coupled to the input terminals so as to maintain the voltage across the discharge tube at a value below the striking voltage of the discharge tube in the second position of the switch.
Claim 10
Dependent Claim
47 words
An irradiation apparatus as claimed in claim 7 wherein the first circuit connecting means connects the PTC resistor in parallel with the first switch and said impedance element includes an infra-red radiator and said discharge tube comprises a high pressure mercury vapor tube that emits ultraviolet radiation.
Claim 11
Dependent Claim
79 words
An irradiation apparatus as claimed in claim 5 wherein the discharge tube includes a separate starting electrode, and said reignition preventing means includes a second switch coupled to the first switch so that both switches open and close in synchronism, and second means connecting the second switch in circuit with the tube starting electrode so that in the open position of the second switch the starting electrode is switched out of circuit thereby preventing reignition of the discharge tube.
Claim 12
Dependent Claim
56 words
An irradiation apparatus as claimed in claim 9 further comprising a timer coupled to said first and second switches for controlling the irradiation period, said timer operating said switches from the first position to the second position at the termination of the irradiation period, said second position of the second switch being the open position thereof.
Claim 13
Dependent Claim
31 words
An irradiation apparatus as claimed in claim 9 wherein said impedance element includes an infra-red radiator and said discharge tube comprises a high pressure mercury vapor tube that emits ultraviolet radiation.
Claim 14
Dependent Claim
24 words
An irradiation apparatus as claimed in claim 9 wherein the first circuit connecting means connects the PTC resistor in parallel with the first switch.
Claim 15
Dependent Claim
38 words
An irradiation apparatus as claimed in claim 12 wherein said second circuit connecting means connects the second switch in series with the discharge path defined by the starting electrode and one main tube electrode across the input terminals.
References Cited (Backward Citations)
US3014156A
Cited
US3262012A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-03-21 | 1980-09-20 | 1981-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-03-21 | 1984-09-20 | 1985-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-03-21 | 1988-09-20 | 1989-03-22 | $7700.00 | Window Closed / Lapsed |