Method for operating power window apparatus having safety device

• US 5,459,379 A
• Filed: 07/12/1993
• Issued: 10/17/1995
• Est. Priority Date: 10/21/1992
• Status: Expired due to Fees

• Current Assignee: Koito Manufacturing Company Limited
• Original Assignee: Koito Manufacturing Company Limited
• Inventors: Tajima, Keiichi, Nakayama, Toru, Takeda, Hitoshi
• Primary Examiner(s): Ro, Bentsu
• Application Number:
  US08/089,567
• Time in Patent Office: 827 Days
• Field of Search: 318/256, 318/264, 318/265, 318/266, 318/267, 318/286, 318/434, 318/466, 318/467, 318/468, 318/469, 388/903, 388/907.5, 388/912, 49/26, 49/28, 340/825.57, 340/825.62, 340/825.65
• US Class Current: 318/469
• CPC Class Codes: E05F 15/41 Detection by monitoring transmitted force or torque E05F15/48 takes precedence; Safety couplings with activation dependent upon torque or force, e.g. slip couplings
• CPC Class Codes: E05F 15/695 Control circuits therefor
• CPC Class Codes: E05Y 2900/55 Windows
• CPC Class Codes: H02H 7/0851 for motors actuating a movable member between two end positions, e.g. detecting an end position or obstruction by overload signal

Abstract

A method for operating power window apparatus with a safety device which stops the closing operation of the window in response to the detection of an object-caught state, which prevents the incomplete close of the window, and can accurately detect the object-caught state. The opening/closing position of the window is detected by counting pulses generated as the window moves. A region where a safety control can be carried out is determined on the basis of the detected opening/closing position. When the window reaches a position near a position where the window is fully closed, the count indicative of the opening/closing position detector is reset. The resetting operation is carried out so that a time point where the relative speed of the window is reduced is set at the fully closed position of the window.

Claims

1. A method for operating a power window apparatus having a safety device for carrying out a safety control operation upon detection of a state where an object is caught in a window driven by a motor, comprising the steps of:

generating pulses in response to movement of said window and counting said pulses to produce a count indicative of a present position of said window;

detecting when said window is in a safety control region of movement of said window where a safety control operation is permitted to be carried out by comparing said count indicative of said present position of said window with a reference value;

when said window is in said region of movement where a safety control operation is permitted, detecting a speed of movement of said window and performing said safety control operation when said speed of movement decreases below a predetermined value;

detecting when said window reaches a predetermined position near a position where said window is fully closed based on said detected speed, said predetermined position corresponding to an upper limit of said safety control region;

disabling said safety control operation when said window is in a region between said predetermined position and said position where said window is fully closed; and

resetting said count when said predetermined position is detected in said detecting step.

2. The method of claim 1, wherein said predetermined position is a position where said window engages a structure which impedes movement of said window so as to reduce said speed of said window.

3. The method of claim 1, wherein said step of generating pulses comprises generating electrical pulses in response to rotation of said motor driving said window.

4. The method of claim 1, wherein said step of resetting said count comprises resetting said count to a zero value.

5. The method of claim 4, wherein said said count is reset when said count is negative.

6. A method for operating a power window apparatus having a safety device for carrying out a safety control operation upon detection of a state where an object is caught in a window driven by a motor, comprising the steps of:

generating pulses in response to movement of said window and counting said pulses to produce a count indicative of a present position of said window;

detecting when said window is in a region of movement of said window where a safety control operation is permitted to be carried out by comparing said count indicative of said present position of said window with a reference value;

when said window is in said region of movement where a safety control operation is permitted, detecting a speed of movement of said window and performing said safety control operation when said speed of movement decreases below a predetermined value;

detecting when said window reaches a predetermined position near a position where said window is fully closed;

disabling said safety control operation when said window is in a region between said predetermined position and said position where said window is fully closed; and

resetting said count when said predetermined position is reached, wherein said step of generating pulses comprises generating electrical pulses in response to rotation of said motor driving said window, and wherein said step of detecting a speed of movement of said window and performing a safety control operation when said speed of movement decreases below a predetermined value comprises;

detecting an absolute speed of said motor by detecting a pulse interval of said pulses;

comparing the detected absolute speed with a first reference value;

detecting a relative speed of said motor by detecting an on/off ratio of said pulses;

comparing the detected relative speed with a second reference value; and

performing said safety control operation when either said detected absolute speed falls below said first reference value or said detected relative speed falls below said second reference value.