Assignee
SIGMA INSTRUMENTS INC
US·37 granted patents·855 citations·filing 1972–2004
Top patents by PatentIndex Score
37 records- 0193US4255696ASynchronous motor systemSIGMA INSTRUMENTS INC·Filed 1976·Granted Mar 10, 1981·51 cites·14 claims
- 0290US5124642APower line post insulator with dual inductor current sensorSIGMA INSTRUMENTS INC·Filed 1989·Granted Jun 23, 1992·79 cites·14 claims
- 0389US4763034AMagnetically enhanced stepping motorSIGMA INSTRUMENTS INC·Filed 1987·Granted Aug 9, 1988·67 cites·20 claims
- 0488US4271384ASynchronous motor driveSIGMA INSTRUMENTS INC·Filed 1977·Granted Jun 2, 1981·35 cites·21 claims
- 0586US4025810ALow noise synchronous motorsSIGMA INSTRUMENTS INC·Filed 1975·Granted May 24, 1977·41 cites·19 claims
- 0683US4712028AMagnetically assisted stepping motorSIGMA INSTRUMENTS INC·Filed 1984·Granted Dec 8, 1987·36 cites·16 claims
- 0783US4112319ASynchronous motor with heterogeneously pitched teethSIGMA INSTRUMENTS INC·Filed 1976·Granted Sep 5, 1978·35 cites·24 claims
- 0881US4984124AFaulted current indicator with inrush restraintSIGMA INSTRUMENTS INC·Filed 1989·Granted Jan 8, 1991·41 cites·14 claims
- 0981US3956650ALaminar-rotor synchronous inductor motorSIGMA INSTRUMENTS INC·Filed 1972·Granted May 11, 1976·26 cites·8 claims
- 1079US5029039ACurrent adaptive fault indicatorSIGMA INSTRUMENTS INC·Filed 1989·Granted Jul 2, 1991·34 cites·12 claims
- 1177US4683472ASignal reading system such as for remote reading of metersSIGMA INSTRUMENTS INC·Filed 1982·Granted Jul 28, 1987·30 cites·19 claims
- 1275US3978690ASelective positioning system particularly for controlling guide bars of knitting machinesSIGMA INSTRUMENTS INC·Filed 1975·Granted Sep 7, 1976·14 cites·49 claims
- 1374US4700123APower distribution systems and means for control thereofSIGMA INSTRUMENTS INC·Filed 1985·Granted Oct 13, 1987·30 cites·20 claims
- 1474US4423343ASynchronous motor systemSIGMA INSTRUMENTS INC·Filed 1981·Granted Dec 27, 1983·29 cites·13 claims
- 1567USD530019SPersonal massagerSIGMA INSTRUMENTS INC·Filed 2004·Granted Oct 10, 2006·19 cites·1 claims
- 1667US4728830AElectric motor with magnetic enhancementSIGMA INSTRUMENTS INC·Filed 1986·Granted Mar 1, 1988·28 cites·12 claims
- 1766US5136456AFaulted current indicator with protection against temporary overloads and transientsSIGMA INSTRUMENTS INC·Filed 1989·Granted Aug 4, 1992·19 cites·7 claims
- 1863US4258276ASwitching circuit for connecting an AC source to a loadSIGMA INSTRUMENTS INC·Filed 1978·Granted Mar 24, 1981·10 cites·5 claims
- 1962US4782287AWatt-hour meterSIGMA INSTRUMENTS INC·Filed 1986·Granted Nov 1, 1988·20 cites·7 claims
- 2059US4488069AStepping motorSIGMA INSTRUMENTS INC·Filed 1983·Granted Dec 11, 1984·17 cites·9 claims
- 2157US4859925APower transmission systems and means for control thereofSIGMA INSTRUMENTS INC·Filed 1986·Granted Aug 22, 1989·15 cites·37 claims
- 2256US5045778AFault indicator with inrush restraintSIGMA INSTRUMENTS INC·Filed 1989·Granted Sep 3, 1991·19 cites·9 claims
- 2355US5055771AFaulted current indicators with improved signal to noise ratiosSIGMA INSTRUMENTS INC·Filed 1989·Granted Oct 8, 1991·16 cites·16 claims
- 2454US5003426AFaulted current indicators and inrush restraints thereforSIGMA INSTRUMENTS INC·Filed 1989·Granted Mar 26, 1991·16 cites·20 claims
- 2550US4172998ACondition operated load controlSIGMA INSTRUMENTS INC·Filed 1977·Granted Oct 30, 1979·11 cites·30 claims
- 2649US4272712APhase locked loop control systemSIGMA INSTRUMENTS INC·Filed 1979·Granted Jun 9, 1981·11 cites·7 claims
- 2748US4675590AStepping motor driver with mid-frequency stability controlSIGMA INSTRUMENTS INC·Filed 1985·Granted Jun 23, 1987·11 cites·20 claims
- 2848US4163971ASystems for displaying analog valuesSIGMA INSTRUMENTS INC·Filed 1975·Granted Aug 7, 1979·11 cites·54 claims
- 2945US6539328B1Device and process for measurement and treatment of spinal mobilitySIGMA INSTRUMENTS INC·Filed 1999·Granted Mar 25, 2003·52 cites·38 claims
- 3045US5111189AFault indicator with timing controlSIGMA INSTRUMENTS INC·Filed 1989·Granted May 5, 1992·9 cites·7 claims
- 3138US5097202AFaulted current indicators with improved signal to noise ratiosSIGMA INSTRUMENTS INC·Filed 1989·Granted Mar 17, 1992·6 cites·28 claims
- 3238US3995202ACondition-initiated load control circuitSIGMA INSTRUMENTS INC·Filed 1974·Granted Nov 30, 1976·4 cites·24 claims
- 3335US4864264ABistable toggling indicatorSIGMA INSTRUMENTS INC·Filed 1988·Granted Sep 5, 1989·6 cites·4 claims
- 3435US4606231AStrain gauge measuring systemSIGMA INSTRUMENTS INC·Filed 1985·Granted Aug 19, 1986·3 cites·24 claims
- 3531US4438381ASynchronous motor systemSIGMA INSTRUMENTS INC·Filed 1982·Granted Mar 20, 1984·2 cites·8 claims
- 3629US4968884AVertically sensitive outdoor lighting controlsSIGMA INSTRUMENTS INC·Filed 1989·Granted Nov 6, 1990·1 cites·5 claims
- 3725US4980790AFault indicating meansSIGMA INSTRUMENTS INC·Filed 1989·Granted Dec 25, 1990·1 cites·10 claims
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