Piezo based energy harvesting for e-latch systems

• US 9,416,565 B2
• Filed: 11/21/2013
• Issued: 08/16/2016
• Est. Priority Date: 11/21/2013
• Status: Expired due to Fees

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Papanikolaou, Kosta, Patel, Rajesh K
• Primary Examiner(s): WILLIAMS, MARK A
• Application Number:
  US14/086,582
• Publication Number:
  US 20150137531A1
• Time in Patent Office: 999 Days
• Field of Search: 292/201
• US Class Current: 1/1
• CPC Class Codes: B60J 5/00 Doors B60J10/00 takes precedence; window aspects B60J1/00 ; side board or tailgate structures for open load compartments B62D33/023
• CPC Class Codes: E05B 77/28 for anti-theft purposes, e.g. double-locking or super-locking
• CPC Class Codes: E05B 81/04 Electrical electrical circuits E05B81/54
• CPC Class Codes: E05B 81/14 operating on bolt detents, e.g. for unlatching the bolt
• CPC Class Codes: E05B 81/56 Control of actuators
• CPC Class Codes: E05B 81/76 Detection of handle operation; Detection of a user approaching a handle; Electrical switching actions performed by door handles
• CPC Class Codes: E05B 81/77 comprising sensors detecting the presence of the hand of a user
• CPC Class Codes: E05B 81/84 using manually operated generator means
• CPC Class Codes: E05B 81/86 using capacitors
• CPC Class Codes: E05B 85/10 Handles
• CPC Class Codes: H02N 2/186 Vibration harvesters
• CPC Class Codes: Y10T 292/1082 Motor

Abstract

A vehicle door includes an electrically-powered latch and a user input feature that can be actuated by a user to cause the electrically-powered latch to unlatch. An electrical energy storage device is operably connected to the electrically-powered latch, and a piezoelectric device is mounted to the door. The piezoelectric device can be manually actuated by a user to charge the electrical energy storage device, and electrical energy from the electrical energy storage device can be utilized to actuate the electrically-powered latch to thereby unlatch the latch. The user input feature may comprise a switch or sensor located adjacent a door handle/latch release on an inside and/or an outside of the vehicle door. The electrical energy storage device may comprise an emergency battery, capacitor, or other electrical device.

Claims

1. A vehicle door, comprising:

an electrically-powered latch defining latched and unlatched states;

a user input feature comprising a switch having a movable switch member actuated by a user and causing the electrically-powered latch assembly to change from the latched state to the unlatched state in order to unlatch the door;

an electrical energy storage device that is operably connected to the electrically-powered latch;

a piezoelectric device having a bendable piezoelectric element operably connected to the electrical energy storage device such that the piezoelectric device is manually actuated by a user to charge the electrical energy storage device; and

wherein the bendable elements is positioned directly adjacent the movable switch member;

electrical energy from the electrical energy storage device is utilized to actuate the electrically-powered latch to thereby unlatch the electronically-powered latch.

2. The vehicle door of claim 1, wherein:

the switch is mounted to the vehicle door.

3. The vehicle door of claim 2, wherein:

the switch is mounted on the exterior side of the door.

4. The vehicle door of claim 3, wherein:

the door has an exterior surface portion, the door including a handle on the exterior side of the door with an inner side facing the exterior surface portion; and

the piezoelectric device is mounted on the inner side of the handle.

5. The vehicle door of claim 4, wherein:

the bendable piezoelectric elements generates electrical energy upon bending, whereby the bendable piezoelectric element contacts the movable switch member and actuates the switch upon bending of the bendable piezoelectric element.

6. The vehicle door of claim 5, including:

an interior latch release including an interior piezoelectric device that can be manually actuated by a user from inside the vehicle to generate electrical power to actuate the electrically-powered latch to unlatch the door, and an interior switch that can be actuated from inside the vehicle to unlatch the electrically-powered latch.

7. The vehicle door of claim 1 including:

an actuating member movably mounted to the interior side of the vehicle door; and

wherein;

the user input feature comprises a switch mounted on the interior side of the door;

the piezoelectric device is configured to be manually actuated by movement of the actuating member.

8. The vehicle door of claim 7, wherein:

the switch includes a movable switch member;

the piezoelectric device includes a bendable element that generates electrical energy upon bending.

9. The vehicle door of claim 8, including:

a base mounted to the interior side of the vehicle door; and

wherein;

the actuating member movably engages the base;

the bendable element comprises a piezoelectric beam having a first end that is fixed to the base; and

upon movement of the actuating member, the actuating member engages and bends the bendable element and also engages and moves the movable switch member.

10. A device for unlatching a vehicle door having an electrically-powered latch, the device comprising:

a base;

a piezoelectric device having a bendable piezoelectric element with a first end fixed to the base and a portion that moves relative to the first end upon bending of the bendable piezoelectric element;

a switch having a movable switch member, wherein movement of the movable switch member generates an unlatch signal to unlatch an electrically-powered latch; and

wherein;

the piezoelectric device is configured to generate electrical power that is utilized to power the electrically-powered latch; and

wherein the bendable piezoelectric element is disposed directly adjacent the movable switch.

11. The device of claim 10, wherein:

the bendable piezoelectric element includes a second end that moves relative to the base.

12. The device of claim 10, wherein:

the device includes an exterior door handle having an inside surface that faces an exterior surface of a door when the handle is installed on a vehicle door; and

wherein;

the switch and the piezoelectric device are disposed on the inside surface of the handle.

13. The device of claim 12, wherein:

the bendable piezoelectric element engages and moves the movable switch member upon bending of the bendable piezoelectric element.

14. A vehicle door including the latch device of claim 10, wherein:

the vehicle door defines an exterior side and an interior side, and wherein the movable switch member is disposed on the interior side of the vehicle door.

15. The vehicle door of claim 14, wherein:

the vehicle door includes a base;

the bendable piezoelectric element is mounted to the base;

the vehicle door includes a movable actuating member that movably engages the base, and wherein the movable actuating member is configured to operably engage the movable switch member and the bendable piezoelectric element whereby a user can manually move the movable actuating member and move the movable switch member and bend the bendable piezoelectric element.

16. A vehicle door comprising:

an electrically-powered latch;

a controller;

a movable switch;

primary and secondary batteries;

a bendable piezoelectric element positioned directly adjacent the movable switch;

an actuating member that simultaneously engages the switch and the piezoelectric element and bends a free end of the piezoelectric element to generate electrical energy that charges the secondary battery, whereby the controller unlatches the electrically-powered latch in response to the movable switch being actuated.

17. The vehicle door of claim 16, wherein:

the vehicle door defines an outer side and an inner side;

the switch and the bendable piezoelectric element are disposed on the inner side of the vehicle door.

18. The vehicle door of claim 17, wherein:

the vehicle door includes a base and an actuating member movably engaging the base for reciprocating movement whereby reciprocating movement of the actuating member actuates the switch and bends the bendable piezoelectric element.

19. The vehicle door of claim 18, wherein:

the bendable piezoelectric element has a first end that is rigidly mounted to the base, and a second end that is substantially free, and wherein the actuating member engages the bendable piezoelectric element adjacent the second end.

20. The vehicle door of claim 16, wherein:

the controller is operably connected to the switch, the primary and secondary batteries, the electrically-powered latch, and the bendable piezoelectric element, and wherein;

the vehicle door includes an illuminated indicator adjacent the actuating member, and wherein the controller causes the illuminated indicator to generate a visible signal if the bendable piezoelectric element needs to be actuated to charge the secondary battery due to a failure of the primary battery.