US3867696A
Expired / Lapsed
US
⏱️ 0.0 years remaining
An improved electrical current measuring meter having integral calibration and zero adjustment means
Assignee: Individual
•
Filing: 1974-01-04
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Granted: 1975-02-18
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Expires: 1994-01-04
Abstract
Abstract An improved electrical current measuring meter is disclosed which has a case with a transparent front face exposing an elongated pointer and a measuring scale, wherein the pointer carries a circular magnet and is rotatable on a shaft that extends forwardly from the inner frame of the case. A thin, horizontal current conducting member is attached to the inner frame and carries the current to be measured, the interaction of the current and the magnet of the pointer producing a torque that rotates the pointer in proportion to the magnitude of the current. The magnetic attraction between the conducting member and the magnet on the pointer keeps the pointer on the shaft. The inner frame of the case has a circular opening in the back that is concentric with the shaft and is adapted to receive a magnet holder containing a second magnet therein which is adjustably and frictionally held due to the resilience of the holder. Thus, the distance of the second magnet from the conducting member and the pointer as well as the angular position may be varied to calibrate the meter as well as provide a zero adjustment of the pointer.
Inventors
- 👤 Eugene B Raymond
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 23:08
CPC Classifications
G; G01; G01R; G01R5/00; G01R5/14; G01R5/16; G01R11/00; G01R11/02
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
210 words
A meter for measuring electrical current in a circuit, comprising: case means, having front and back sides and a visible front face for placing indicia defining a measuring scale, a shaft secured to the case means and extending toward the front thereof for supporting a pointer means, and a generally circularly shaped opening in the back located rearwardly of the shaft; pointer means having a central portion with an aperture therein for receiving said shaft, an elongated pointer extending downwardly from the central portion, a counterweight portion opposite said pointer, and a first ferromagnetic member attached to the central portion, said pointer means being balanced and rotatable around said shaft; an electrical current conductive member attached to the housing and having an elongated portion extending adjacent said pointer means for influencing the same in response to current flowing through the conductive member; calibrating and zero adjustment means comprising a holder having a second ferromagnetic member secured thereto, said holder having a resilient outer periphery for frictionally engaging an inner surface of said opening of said case means, said calibrating and zero adjustment means being rotatable and spacially adjustable relative to said pointer means and said elongated portion of said current conductive means for enabling calibrating and adjustment of said meter.
Claim 2
Dependent Claim
210 words
A meter for measuring electrical current in a circuit, comprising: case means, having front and back sides and a visible front face for placing indicia defining a measuring scale, a shaft secured to the case means and extending toward the front thereof for supporting a pointer means, and a generally circularly shaped opening in the back located rearwardly of the shaft; pointer means having a central portion with an aperture therein for receiving said shaft, an elongated pointer extending downwardly from the central portion, a counterweight portion opposite said pointer, and a first ferromagnetic member attached to the central portion, said pointer means being balanced and rotatable around said shaft; an electrical current conductive member attached to the housing and having an elongated portion extending adjacent said pointer means for influencing the same in response to current flowing through the conductive member; calibrating and zero adjustment means comprising a holder having a second ferromagnetic member secured thereto, said holder having a resilient outer periphery for frictionally engaging an inner surface of said opening of said case means, said calibrating and zero adjustment means being rotatable and spacially adjustable relative to said pointer means and said elongated portion of said current conductive means for enabling calibrating and adjustment of said meter.
Claim 3
Dependent Claim
54 words
A meter as defined in claim 1 wherein said pointer means has a generally circular shaped central portion with an axially aligned sleeve containing said aperture, the weight of said elongated pointer approximating the weight of said counterweight portion, said central portion, elongated pointer and counterweight portion being integrally formed of a non-ferromagnetic material.
Claim 4
Dependent Claim
34 words
A meter as defined in claim 2 wherein said first magnetic member is of a generally flat circular shape approximating the size of the central portion of said pointer means and being attached thereto.
Claim 5
Dependent Claim
41 words
A meter as defined in claim 3 wherein said first ferromagnetic member has a concentric aperture with a diameter greater than a diameter of said sleeve, said magnetic member being attached to said central portion so that said sleeve extends therethrough.
Claim 6
Dependent Claim
79 words
A meter as defined in claim 1 wherein said current conductive member comprises said elongated portion having a width approaching the width of said first ferromagnetic member and transversly extending end portions directed toward said back of the meter, said case means having a pair of slots for receiving said end portions, each of said end portions having an inwardly angled resilient ear, the ends of which abut said case means to prohibit separation of the conductive member therefrom.
Claim 7
Dependent Claim
33 words
A meter as defined in claim 5 wherein said conductive member has an aperture therein through which said shaft extends, said aperture being centrally located in said elongated portion of said conductive member.
Claim 8
Dependent Claim
35 words
A meter as defined in claim 5 wherein said transverse end portions of said conductive member extend outwardly of the back of said case means and define electrical terminals for connection to an electrical circuit.
Claim 9
Dependent Claim
40 words
A meter as defined in claim 1 wherein said pointer means is rotatable on said shaft and the magnetic attraction between said first ferromagnetic member and said conductive member provides sufficient force to maintain said pointer means on said shaft.
Claim 10
Dependent Claim
35 words
A meter as defined in claim 4 wherein said flat circular shaped ferromagnetic member is formed of a ceramic ferromagnetic material that is magnetized along its diameter resulting in oppositely disposed north and south poles.
Claim 11
Dependent Claim
40 words
A meter as defined in claim 1 wherein said second ferromagnetic member has a generally flat circular shape and is comprised of a ceramic magnetic material, magnetized along the diameter so as to produce oppositely disposed north and south poles.
Claim 12
Dependent Claim
51 words
A meter as defined in claim 1 wherein said case means is of a non-ferromagnetic material and comprises an inner frame portion and an interlocking outer cover, a portion of said cover adjacent said front face being generally transparent to enable observation of said elongated pointer and said visible front face.
Claim 13
Dependent Claim
46 words
A meter as defined in claim 11 wherein said cover is spaced away from said pointer means, one of either said cover or said inner frame having stop means located on opposite sides of said measuring scale indicia to limit the movement of said elongated pointer.
Claim 14
Dependent Claim
45 words
A meter as defined in claim 11 wherein side walls of said inner frame are in contact with the inner surface of side walls of said cover, said contacting side walls having cooperative recesses and ears to resiliently lock said inner frame and cover together.
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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) | 1978-02-17 | 1978-08-19 | 1979-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-02-17 | 1982-08-19 | 1983-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-02-17 | 1986-08-19 | 1987-02-18 | $7700.00 | Window Closed / Lapsed |