Method to detect end-of-life in latches

• US 10,604,970 B2
• Filed: 05/04/2017
• Issued: 03/31/2020
• Est. Priority Date: 05/04/2017
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Briggs, Erin Rose, Khan, Muhammad Omer, Papanikolaou, Kosta, Puscas, Livianu Dorin, Radjewski, Christopher Matthew
• Primary Examiner(s): Cumar, Nathan
• Application Number:
  US15/586,984
• Publication Number:
  US 20180320420A1
• Time in Patent Office: 1,062 Days
• Field of Search: 292201
• CPC Class Codes: E05B 15/04 Spring arrangements in locks E05B3/065, E05B15/101, E05B15/143, E05C19/06 take precedence
• CPC Class Codes: E05B 17/0062 with destructive disengagement
• CPC Class Codes: E05B 17/226 Displays on locks, e.g. LED or LCD screens on handles E05B1/0084; on keys E05B19/0088
• CPC Class Codes: E05B 39/04 with counting or registering devices time recording locks G07C1/32
• CPC Class Codes: E05B 81/14 operating on bolt detents, e.g. for unlatching the bolt
• CPC Class Codes: E05B 81/66 the bolt position, i.e. the latching status
• CPC Class Codes: E05B 81/68 by sensing the position of the detent
• CPC Class Codes: G07C 5/0825 using optical means

Abstract

A door latch system for vehicle doors, deck lids, hatches, hoods, or the like includes a latch. The latch has a predicted life that may be based on a number of times the latch is used. A sensor that generates a signal that can be used to determine if the latch has reached the predicted life and/or if the latch is approaching the predicted life and/or if the latch has exceeded the predicted life. The system may include a controller that causes a display in a vehicle interior to display an end-of-life signal.

Claims

1. A door latch system for vehicle doors, comprising:

a latch for vehicle doors that is configured to shift between latched and unlatched configurations, wherein the latch includes a spring and a rotatable claw that is configured to engage a striker, and a pawl that engages the claw and prevents rotation of the claw when the latch is in a latched configuration, wherein the spring is operably connected to the claw and/or the pawl such that the spring cycles upon movement of the claw and/or the pawl, the latch having a predicted life based on a number of times the latch is used;

a sensor that generates one or more signals that can be used to determine if the latch has reached a predefined end-of-life criteria;

wherein the spring is configured to fail after a predefined number of cycles, and wherein failure of the spring causes actuation of the sensor; and

;

wherein the system is configured to generate an end-of-life signal based on the one or more signals from the sensor when the signals indicate that the latch has reached the predefined end-of-life criteria.

2. The door latch system of claim 1, wherein:

the latch includes a rotatable claw that is configured to engage a striker, and a pawl that engages the claw and prevents rotation of the claw when the latch is in a latched configuration; and

the sensor is configured to detect movement and/or position of at least one of the claw and the pawl.

3. The door latch system of claim 1, wherein:

the latch includes a rotatable claw that is configured to engage a striker, and a pawl that engages the claw and prevents rotation of the claw when the latch is in a latched configuration; and

wherein the sensor is configured to detect engagement and/or disengagement of the pawl with the claw.

4. The door latch system of claim 1, including:

a controller operably connected to the sensor, wherein the controller is configured to generate an end-of-life signal when the predefined end-of-life criteria exists.

5. The door latch system of claim 4, including:

a display that is operably connected to the controller; and

wherein the controller causes the display to display a message indicating that the latch has reached its end-of-life and/or that the latch is approaching its end-of-life.

6. The door latch system of claim 1, wherein:

the latch includes an electrically-powered actuator that is configured to shift the pawl between latched and unlatched positions to thereby unlatch the latch; and

the sensor comprises a switch that detects engagement of the pawl with the claw and/or movement and/or position of the claw and/or the pawl.

7. The door latch system of claim 1, wherein:

the spring comprises a torsion spring that is operably connected to the claw or the pawl.

8. The door latch system of claim 1, wherein:

the spring comprises a compression spring that is operably connected to the claw or the pawl.

9. A door latch system for vehicle doors comprising:

a latch for vehicle doors having latched and unlatched configurations, wherein, in use, the latch cycles between the latched and unlatched configuration;

a counting device that counts the number of cycles of the latch and/or the number of configuration changes from one of the latched and unlatched states to the other of the latched and unlatched states;

a controller that is operably connected to the counting device, the controller being configured to generate an end-of-life signal indicating that the latch has reached an end-of-life condition and/or is approaching an end-of-life condition, wherein the controller generates the end-of-life signal based on predefined criteria, the predefined criteria comprising at least one of an allowable number of cycles of the latch and/or an allowable number of configuration changes of the latch.

10. The door latch system of claim 9, wherein:

the latch includes a rotatable claw and a pawl that selectively engages the claw to prevent rotation of the claw when the latch is in the latched configuration;

the counting device comprises a switch that engages the claw and/or the pawl.

11. The door latch system of claim 10, wherein:

the latch includes an electrically-powered actuator that shifts the pawl between latched and unlatched configurations.

12. The door latch system of claim 10, including:

a movable door handle that is mechanically connected to the pawl such that movement of the door handle moves the pawl to a disengaged position to unlatch the door.

13. The door latch system of claim 9, wherein:

the counting device comprises a spring that is configured to fail after a predefined number of cycles before the latch reaches the end-of-life condition, and a switch that is actuated when the spring fails.

14. A vehicle latch system, comprising:

a vehicle door latch;

a sensor that detects latch operations including latching and/or unlatching of the latch;

a controller configured to generate an end-of-life signal if the controller determines that a predefined number of latch operations has occurred.

15. The vehicle latch system of claim 14, wherein:

the sensor comprises a switch that is actuated when the latch is latched and/or when the latch is unlatched.

16. The vehicle latch system of claim 14, wherein:

the latch includes a spring that is configured to fail after a predefined number of cycles corresponding to a predicted end-of-life of the latch, and wherein failure of the spring actuates the sensor.

17. The vehicle latch system of claim 16, wherein:

the spring comprises a torsion spring or a compression spring.

18. The vehicle latch system of claim 14, wherein:

the latch includes a rotatable claw and a pawl that selectively engages the claw to prevent rotation of the claw when the latch is in the latched configuration; and

wherein the sensor is configured to sense position and/or movement of the claw and/or the pawl.

19. The vehicle latch system of claim 18, wherein:

the latch includes a powered actuator that moves the pawl from a latched position to an unlatched position.