US3829776A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pen type voltmeter
Assignee: Individual
•
Filing: 1973-07-31
•
Granted: 1974-08-13
•
Expires: 1993-07-31
Abstract
Abstract A relatively compact voltage tester generally in the form of a pen or pencil adapted to be carried in a shirt pocket or the like and including a tubular casing with a spring biased connecting rod attached to a metallic probe, both being movably mounted in the casing with the probe projecting from one end thereof. The probe is applied to the circuit point to be tested whereupon the voltage appearing thereat is coupled across a selected strip resistor also carried in the casing. The rod is mechanically connected to a sliding contact member positioned against the strip resistor which then acts as a voltage pick off. The selected strip resistor and contact member comprise a potentiometer and is operable such that as the probe is depressed against the spring by pushing the casing toward the circuit point, a neon lamp lights at a certain depressed position. A pointer also coupled to the rod acts in combination with a calibrated scale on the outer surface of the casing to provide a reading of the voltage applied across the potentiometer.
Inventors
- 👤 E Lozoya
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 11:03
CPC Classifications
G; G01; G01R; G01R19/00; G01R19/145; G01R19/155
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
340 words
An electrical tester particularly adapted but not restricted to multi-range electrical measurements, comprising in combination: a casing including a first and second axially aligned interior cavity and having a linearly extending graduated scale comprising calibrated indicia for providing a direct reading of the desired measurement located on the outer surface of said casing; a retractable electrical contact probe mounted in and projecting from one end of said casing and constituting one terminal of an electrical measuring circuit; single electrical conductor means extending from said casing and constituting the other terminal of said electrical measuring circuit; spring bias means mounted in said first cavity and biasing said contact probe to a normally projected position; a unitary linearly extending strip resistor element for a desired range of electrical measurement located in said second cavity; an electrical slide contact member in electrical contact with said resistor element located in said second cavity; an indicator element located in a slot in said casing adjacent said graduated scale and cooperating therewith to provide said direct reading of the desired measurement; means mechanically coupling the contact probe, the slide contact member and said indicator element whereby the holding of the casing and applying the contact probe to a point of an electrical circuit being tested and then pressing the casing toward the point under test causes the caSing together with the graduated scale and resistor element to advance relative to the contact probe, the slider element and the indicator against the action of the spring bias means; an electrical lamp adapted to light upon the application of a predetermined voltage thereacross, mounted on the casing; and electrical circuit means coupling said resistor element, said slide contact and said lamp to said contact probe and said electrical conductor means providing a measuring circuit for an electrical parameter whereupon said lamp lights upon a selected pressing of said casing toward said point to be measured and the magnitude of the parameter being measured will be indicated by the relative position of said indicator element and the graduated scale.
Claim 2
Dependent Claim
340 words
An electrical tester particularly adapted but not restricted to multi-range electrical measurements, comprising in combination: a casing including a first and second axially aligned interior cavity and having a linearly extending graduated scale comprising calibrated indicia for providing a direct reading of the desired measurement located on the outer surface of said casing; a retractable electrical contact probe mounted in and projecting from one end of said casing and constituting one terminal of an electrical measuring circuit; single electrical conductor means extending from said casing and constituting the other terminal of said electrical measuring circuit; spring bias means mounted in said first cavity and biasing said contact probe to a normally projected position; a unitary linearly extending strip resistor element for a desired range of electrical measurement located in said second cavity; an electrical slide contact member in electrical contact with said resistor element located in said second cavity; an indicator element located in a slot in said casing adjacent said graduated scale and cooperating therewith to provide said direct reading of the desired measurement; means mechanically coupling the contact probe, the slide contact member and said indicator element whereby the holding of the casing and applying the contact probe to a point of an electrical circuit being tested and then pressing the casing toward the point under test causes the caSing together with the graduated scale and resistor element to advance relative to the contact probe, the slider element and the indicator against the action of the spring bias means; an electrical lamp adapted to light upon the application of a predetermined voltage thereacross, mounted on the casing; and electrical circuit means coupling said resistor element, said slide contact and said lamp to said contact probe and said electrical conductor means providing a measuring circuit for an electrical parameter whereupon said lamp lights upon a selected pressing of said casing toward said point to be measured and the magnitude of the parameter being measured will be indicated by the relative position of said indicator element and the graduated scale.
Claim 3
Dependent Claim
47 words
The electrical tester as defined by claim 1 wherein said circuit means comprises: first circuit means coupling said contact probe and said electrical conductor means across said resistor element, and second circuit means coupling said electrical lamp across said slide contact member and said electrical conductor means.
Claim 4
Dependent Claim
99 words
The electrical tester as defined by claim 1 and additionally including: another unitary linearly extending strip resistor element located in said second cavity opposite said first-recited resistor element for another desired range of measurement; an electrical conductor extending substantially parallel between said resistor elements; wherein said slide contact member comprises a trifurcated contact member having three resilient electrical contact branches respectively adapted to contact said resistor elements and said electrical conductor; and wherein said electrical circuit means additionally includes switch means operable to selectively connect one of said resistor elements to said contact probe and said electrical conductor means.
Claim 5
Dependent Claim
25 words
The electrical tester as defined by claim 3 wherein said casing has a generally tubular shape of relatively small size for fitting into a pocket.
Claim 6
Dependent Claim
122 words
The electrical tester as defined by claim 1 wherein: said casing is comprised of a relatively slender generally tubular body; and wherein said spring bias means comprises a compression spring and said mechanical coupling means comprises a connecting rod member of non-conductive material extending through said compression spring, said compression spring and said rod member being located in said first cavity, said contact probe being mounted in one end of said rod member, and with said indicator element and said slide contact member attached to the other end of said rod member, said contact probe additionally being in electrical contact with said compression spring at one end thereof and said electrical circuit means being coupled to the other end of said spring.
Claim 7
Dependent Claim
67 words
The electrical tester as defined by claim 5 and additionally including a second linearly extending electrical resistor element located in said second cavity opposite from the earlier recited at least one resistor element with said slide contact member being in common electrical contact with both said resistor elements, and electrical conductor means located intermediate said resistor elements and being in electrical contact with said slide contact member.
Claim 8
Dependent Claim
42 words
The electrical tester as defined by claim 6 wherein said body includes a third cavity behind the second cavity and additionally including switch means located in said third cavity coupled to said electrical circuit means for selecting one of said resistor elements.
Claim 9
Dependent Claim
30 words
The invention as defined by claim 7 wherein said body includes a relatively flat body portion external to said second cavity, said flat body portion having the graduated scale thereon.
Claim 10
Dependent Claim
70 words
The electrical tester as defined by claim 1 wherein said casing is of a generally tubular shape, said spring bias means comprises a longitudinally extending compression spring electrically connected to said contact probe, said mechanical coupling means comprises a connection rod extending through sAid compression spring and having the contact probe secured to one end and said electrical slider member and said indicator element being secured to the other end.
Claim 11
Dependent Claim
78 words
The electrical tester as defined by claim 9 wherein said slider member comprises a trifurcated resilient electrical slide contact member; additionally including a second linearly extending electrical resistor element; and a three walled channel member comprised of electrically conductive material having said at least one and said second linearly extending resistor elements mounted thereon and electrically insulated therefrom, and wherein said trifurcated slide contact member has one contact branch respectively contacting said resistor elements and said channel member.
References Cited (Backward Citations)
US3315163A
Cited
US3694749A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-12 | 1978-02-11 | 1978-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-12 | 1982-02-11 | 1982-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-12 | 1986-02-11 | 1986-08-13 | $7700.00 | Window Closed / Lapsed |