Closing device with a safety function

• US 6,456,027 B1
• Filed: 12/08/2000
• Issued: 09/24/2002
• Est. Priority Date: 02/27/1999
• Status: Expired due to Term

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Pruessel, Holger
• Primary Examiner(s): Fletcher, Marlon T.
• Application Number:
  US09/674,129
• Time in Patent Office: 655 Days
• Field of Search: 318/440-466, 318/484, 318/283, 318/139, 318/286, 318/467, 318/476, 318/280, 318/480, 701/36, 701/49
• US Class Current: 318/445
• CPC Class Codes: H02H 1/04 Arrangements for preventing response to transient abnormal conditions, e.g. to lightning or to short duration over voltage or oscillations; Damping the influence of dc component by short circuits in ac networks
• CPC Class Codes: H02H 3/006 Calibration or setting of parameters
• 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

In a closing device, in particular for a motor vehicle window or sunroof, having a drive motor (4) for pushing a closing element such as a window pane or roof panel across an opening to be closed, a sensor (3) for detecting a force acting on the closing element in the opposite direction to the direction of closing, and a control circuit (1) for monitoring the force and interrupting the closing element'"'"'s closing movement if the sensor (3) detects that the force exceeds a limit value, the control circuit (1) varies the limit value depending on force measured at an earlier point in time. As a result, it is possible to distinguish between disruptive influences on the closing device, in particular external acceleration forces acting on the closing element, from forces arising as a result of a body part being trapped in the opening, reversing of the closing device only being permitted in the latter instance.

Claims

1. A closing device, comprising:

a drive motor for displacing a closing element across and opening to be closed;

a sensor for detecting a force acting on the closing element in a direction that is opposite to a direction of closing;

a control circuit for monitoring the force and interrupting a closing movement of the closing element if the sensor detects that the force exceeds a limit value, wherein;

the control circuit varies the limit value depending on the force measured at an earlier point in time; and

the control circuit increases the limit value for one of a limited time and a limited portion of a path of the closing element if the sensor detects an abrupt decrease in the force.

2. The closing device according to claim 1, wherein:

the closing element includes one of a motor vehicle window and a sunroof.

3. The closing device according to claim 1, wherein:

the control circuit detects one of a length of the limited time period and a length of the limited portion of the path of the closing element during which the decrease in the force lasts, and

the control circuit increases the limit value for one of another time period and a length of another portion of the path of an at least equal order of magnitude.

4. The closing device according to claim 1, wherein:

the control circuit determines a downward acceleration of a motor vehicle during which the decrease in the force lasts, and

the control circuit increases the limit value by an amount that is proportional to the downward acceleration.

5. The closing device according to claim 1, wherein:

the control circuit determines a change in the force based on a distance traveled by the closing element, and

the control circuit increases the limit value if the force as a function of the distance traveled increases at a rate higher than that defined by a limit spring rate.

6. The closing device according to claim 5, wherein:

the limit spring rate is one of greater than and equal to 20 N/mm.

7. The closing device according to claim 5, wherein:

the control circuit increases the limit value by temporarily interrupting a monitoring of the force.

8. The closing device according to claim 1, further comprising:

a memory for storing force values, each one of the force values corresponding to a position of the closing element.

9. The closing device according to claim 8, wherein:

the memory includes sliding averages of the force acting on the closing element in the position of the closing element.

10. The closing device according to claim 8, wherein:

the memory contains sliding averages of the force acting on the closing element in the position of the closing element plus an additional amount.

11. The closing device according to claim 9, wherein:

the control circuit does not update the sliding averages until a deviation in a measured force value relative to a corresponding one of the stored force values has not resulted in an interruption of the closing movement.