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US4934473A Expired / Lapsed US ⏱️ 0.0 years remaining

Motor driven power steering apparatus

Assignee: Aisin Corp
•
Filing: 1989-02-28
•
Granted: 1990-06-19
•
Expires: 2009-02-28
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Abstract

Abstract A motor driven power steering apparatus includes a steering mechanism having a torque detector for detecting torque applied to the mechanism through a steering wheel. An electric motor is connected to the steering mechanism through an electromagnetic clutch. The current in the electric motor is monitored and if it becomes excessive, a control circuit is activated to deactivate the clutch. The electric motor is disconnected from the steering mechanism at the time the engine of the vehicle is starting and at other times during operation of the vehicle to determine if excess current flows through the motor which would be indicative of a malfunction of the electric motor.

Inventors

  • 👤 Takehiko Fushimi
  • 👤 Hiroshi Nakashima

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 16:25
CPC Classifications
B; B62; B62D; B62D5/00; B62D5/04; B62D5/0457; B62D5/0475; B62D5/0478; B62D5/0481

Claims Analysis

Total Claims: 7
Claim 1
Independent Claim 169 words
A motor driven power steering apparatus comprising: a steering mechanism for changing direction of road wheels; torque detecting means for detecting a steering torque applied to a steering wheel; auxiliary torque generating means for generating an auxiliary torque; clutch means for connecting and disconnecting the auxiliary torque generating means to the steering mechanism; control means for controlling magnitude and direction of the generated auxiliary torque in response to the detected steering torque; excessive current detecting means for detecting excessive current flowing through the auxiliary torque generating means; clutch releasing means for activating the clutch means in order to disconnect the auxiliary torque generating means from the steering mechanism; and malfunction detecting means for detecting a malfunction of the auxiliary torque generating means, wherein the malfunction detecting means detects the malfunction by disconnecting the auxiliary torque generating means from the steering mechanism by the clutch releasing means; generating an auxiliary torque by the auxiliary torque generating means; and determining if an excessive current flows through the auxiliary torque generating means.
Claim 2
Dependent Claim 169 words
A motor driven power steering apparatus comprising: a steering mechanism for changing direction of road wheels; torque detecting means for detecting a steering torque applied to a steering wheel; auxiliary torque generating means for generating an auxiliary torque; clutch means for connecting and disconnecting the auxiliary torque generating means to the steering mechanism; control means for controlling magnitude and direction of the generated auxiliary torque in response to the detected steering torque; excessive current detecting means for detecting excessive current flowing through the auxiliary torque generating means; clutch releasing means for activating the clutch means in order to disconnect the auxiliary torque generating means from the steering mechanism; and malfunction detecting means for detecting a malfunction of the auxiliary torque generating means, wherein the malfunction detecting means detects the malfunction by disconnecting the auxiliary torque generating means from the steering mechanism by the clutch releasing means; generating an auxiliary torque by the auxiliary torque generating means; and determining if an excessive current flows through the auxiliary torque generating means.
Claim 3
Dependent Claim 22 words
The apparatus as set forth in claim 1, wherein the malfunction detecting means operates when power is supplied to the control means.
Claim 4
Dependent Claim 20 words
The apparatus as set forth in claim 1, wherein the malfunction detecting means operates when a predetermined time is elapsed.
Claim 5
Dependent Claim 20 words
The apparatus as set forth in claim 1, wherein the malfunction detecting means operates when a predetermined distance is run.
Claim 6
Dependent Claim 21 words
The apparatus as set forth in claim 1, wherein malfunction detecting means further includes a display means for displaying the malfunction.
Claim 7
Dependent Claim 16 words
The apparatus as set forth in claim 1, wherein said clutch means is an electromagnetic clutch.

References Cited (Backward Citations)

US4789040A Cited
WO1988006546A1 Cited
GB2204006A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1993-06-18 1993-12-18 1994-06-19 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1997-06-18 1997-12-18 1998-06-19 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2001-06-18 2001-12-18 2002-06-19 $7700.00 Window Closed / Lapsed

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