Patent Application
20080073917
Although the drawings represent varied embodiments and features of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to illustrate and explain the present invention. The exemplification set forth herein illustrates several aspects of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.
Exemplary embodiments of the present invention relate to an apparatus and method for providing a cinching latch assembly. Furthermore, exemplary embodiments are directed to a bi-directional motor drive actuator operative to move levers to provide a robust, inexpensive structurally simple override function.
In accordance with exemplary embodiments of the present invention a motor turns in one direction for power cinching and in the opposite direction for power unlatching. The motor turns a pinion or worm and engages with a gear train. The output of the gear train rotates a jackscrew, ball screw or lead screw. The lead screw drives a nut axially back and forth. The nut has at least one or two appendages. One appendage of the nut pin follows two cam surfaces one to cinch and one to unlatch. The cam surfaces determine the attitude of the nut. The other appendage of the nut comprises a drive lug that engages a cinch lever for power cinching. The cinch lever rotates with the fork bolt with the latch in a secondary position the nut drive lug must engage the cinch lever. In order to do this, the moment arm with the fork bolt is quite small. The cinch arm surface rotates the nut so that the moment arm to the cinch lever is increased. The moment arm is maximized as the fork bolt rotates to the primary latch position. Once the latch is in primary, the motor receives a reverse pulse. This rotates the nut to the unlatch cam surface and disengages the nut drive lug from the cinch lever.
Power unlatching is achieved by reversing the motor polarity or using the same polarity to disengage the nut drive lug from the cinch lever. The nut is then guided by the unlatch cam surface and the nut travels along the screw and engages a detent release lever the detent release lever raises the detent to unlatch the latch and then the fork bolt is free to rotate from latched to unlatched. Once the fork bolt rotates to the open position or unlatched position, the motor receives a reverse pulse which then allows the detent to engage the fork bolt should the same be rotated into a latched or primary position again.
In the event of a power failure, the nut or the nut appendage must be rotated to the opposite cam surface to allow the drive lug to disengage from either the detent release lever or the cinching lever. This may be achieved by pushing on the nut pin directly or by having another lever engage the nut to reduce the override effort. Once the nut is rotated to the override position, both the cinch and detent release levers are allowed full range of motion (i.e. the detent will fully engage with the fork bolt in a full-bite condition).
The override effort is directly related to the lead of the screw. A larger lead directly relates to higher override efforts and likewise a smaller lead relates to lower efforts. This can be used with both backdrivable and non-backdrivable gear trains. The cam surfaces are set up to ensure proper disengagement from the cinch and detent release levers.
As used herein, the terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another, and the terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. In addition, it is noted that the terms “bottom” and “top” are used herein, unless otherwise noted, merely for convenience of description, and are not limited to any one position or spatial orientation.
The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., includes the degree of error associated with measurement of the particular quantity).
The contents of each of the following U.S. Patents are incorporated herein by reference thereto: U.S. Pat. No. 6,550,825 to Ostrowski et al. entitled “Cinching Door Latch with Planetary Release Mechanism”; U.S. Pat. No. 6,123,372 to Rogers et al. entitled “Door Larch”; U.S. Pat. No. 5,639,130 to Rogers et al. entitled “Rotary Door Cinching Mechanism with Manual Override”; U.S. Pat. No. 5,918,917 to Elton et al. entitled “Vehicle Door Latch with Cinching Mechanism”; and U.S. Pat. No. 6,092,336 to Wright et al. entitled “Power Liftgate Cable Drive with Position Stop”.
The following non-limiting examples further illustrate the various embodiments described herein.
With initial reference to
In accordance with an exemplary embodiment of the present invention the latch assembly rotatably receives a fork bolt having an aperture or receiving area configured to engage a striker or other equivalent member of the vehicle door panel. The fork bolt is configured to rotate from a primary or latched position to a secondary or half latched position to a fully open or unlatched position. Furthermore, the fork bolt is further configured to rotate from the unlatched position to the secondary or half latched position to the primary or latched position. In one exemplary embodiment, the fork bolt is spring biased such that movement of the detent release lever allows the fork bolt to rotate into the unlatched position while movement of the fork bolt from the unlatched to the latched position requires the biasing force of the spring to be overcome.
Actuator assembly 15 further comprises a housing assembly 16, which in an exemplary embodiment is secured to main housing 4. As shown, housing assembly 16 has a first housing portion 17 and a second housing portion 19. The first housing portion has an opening 18 while the second housing portion has an opening 20.
Opening 20 includes a first end portion 21 that defines a first travel limit position, and a second end portion 22 that defines a second travel limit position. First and second end portions or travel limit positions 21 and 22 are interconnected through a pair of opposing side portions 23 and 24. In addition, each side portion has a corresponding cam surfaces 25 and 26.
As best as shown in
In a manner that will become more fully evident below, drive screw 38 is operated or rotated in two opposite directions to translate and rotate a carrier nut 46 between a “home position” and a latched position and between the home position and an unlatched position wherein the home position further includes at least two distinct operational positions. In accordance with an exemplary embodiment the carrier nut has a threaded opening to engage the threads of the drive screw so that rotational movement of the drive screw will cause the carrier nut to translate along an axis defined by the carrier nut.
Furthermore, and as will be described herein rotation of the carrier nut is allowed prior to linear translation. Moreover, the openings 18 and 20 are configured that upon loss of power the carrier nut is capable of being rotated to move a drive lug out of contact with either the cinching lever or the detent release lever.
Referring now to
As will be discussed more fully below, carrier nut and nut pin or drive pin 57 transitions within opening 20 when cinching latch assembly 2 shifts between a home position and a latched configuration illustrated in
In accordance with one exemplary embodiment the carrier nut further comprises a drive lug 58 (
In accordance with an exemplary embodiment the openings 18 and 20 are disposed on opposite sides of housing assembly 16 however, in one alternative exemplary embodiment, the housing assembly is configured to have a single opening for receipt of a single appendage of the carrier nut.
Similar to the nut pin 57, the drive lug 58 translates and rotates within opening 18 when cinching latch assembly 2 shifts between a home position and a latched configuration illustrated in
More specifically and once an associated panel of the vehicle is moved from an open position to a partially closed position a striker of the door panel engages the fork bolt to rotate it from an unlatched position to a secondary position wherein the cinching latch assembly 2 is then activated to rotate the fork bolt from the secondary position to a primary position to draw the panel to a fully closed position, i.e., cinching the panel. As used herein, the secondary position of the fork bolt corresponds to one of two “home positions” of the carrier nut. Each of the two home positions have a different location of the drive lug and the drive pin.
In accordance with an exemplary embodiment of the present invention when the fork bolt is rotated from the unlatched position to a secondary position a sensor positioned to detect movement of the fork bolt from the unlatched position to the secondary position provides a signal to actuate or activate the motor to drive the carrier nut from the home position to the latched position (e.g., power cinching of the latch). During this movement the drive lug contacts the cinching lever and causes the fork bolt to rotate into the latched or primary position.
As the fork bolt is rotated from the secondary position to the primary or latched position the nut pin 57 and the drive lug 58 travel from the home position (
As the carrier nut translates from the home position towards the latched position and from the latched position to the home position the carrier nut is rotated such that nut pin 57 and drive lug 58 are moved in at least two directions as the carrier nut is moved from the home position to the latched position and then from the latched position back to the home position. As the carrier nut moves from home position to the latched position the motor drives the drive screw in one direction causing a linear movement of the carrier nut. In addition, and during this movement the nut pin contacts a cam surface of the opening to cause rotational movement of the carrier nut and the nut pin and the drive lug. During this movement the drive lug rotates into a position such that is contacts a cinching lever 130 (See
Once at the latched position, the motor stops and is activated in an opposite direction to translate the carrier nut from the latched position to the home position. During this change of motor direction the carrier nut will rotate until the either the nut pin or the drive lug contacts a side wall of their respective opening causing the carrier nut to then translate back from the latched position to the home position. This rotation of the carrier nut and the drive lug causes the drive lug to no longer be in contact with the cinching lever of the fork bolt (e.g., allowing movement back to the home position).
In order to latch or transition latching mechanism 2 from the home position (
Once the nut pin 57 reaches first travel stop 20 and the fork bolt 67 is in the latched position the fork bolt 67 is engaged by a detent lever 69 and retained in the latched configuration. Thereafter, the motor is then operated in a reverse direction (e.g., opposite to the direction causing the carrier nut to translate to home from latched) such as by changing input voltage polarity this causes nut pin 57 to move into contact with side portion 24 of opening 20. That is, rotation of drive screw 38 forces nut pin 57 from contacting side portion 23 into contact with side portion 24 thus, nut pin 57 and drive lug 58 rotate first before the carrier nut returns to the home position. Alternatively, contact of the drive lug to a side portion of opening 18 may be used to effect movement back towards the home position. Once the carrier nut is rotated the drive lug is free to move back to the home position (e.g., the drive lug no longer contacts the fork bolt or a cinching lever secured to the fork bolt and the drive lug is free to move back to the home position without effecting the state of the fork bolt).
Continued operating of motor 12 shifts carrier nut 46 back towards the home position, with nut pin 57 sliding along second can surface 26.
In order to effect movement of the carrier nut from the home position to the latched position and back to the home position a micro-switch 70 is positioned to contact a cam surface 71 of the carrier nut. Cam surface 71 has opposing inclined surfaces each being configured to engage the micro-switch as the carrier nut moves back and forth from and to the home position. In accordance with an exemplary embodiment, the micro-switch is normally open (e.g., closing of the switch stops the power to the motor). Referring back now to the previous example (e.g., cinching or movement from home to latched and back to home), once a sensor detects the fork bolt is rotated from the unlatched position to the secondary position the motor is energized and the carrier nut travels toward the latched position the cam surface 71 moves away from the micro-switch and the motor operates until the fork bolt is in the latched position wherein a fork bolt switch located in the latch assembly provides a signal to a controller indicating that the fork bolt is latched. Thereafter, the polarity is reversed to the motor and the carrier nut is driven back towards the home position wherein the cam surface 71 contacts the micro-switch 70 and the motor is stopped and the carrier nut is at the home position.
In order to unlatch or transition latching mechanism 2 from the home position (
Furthermore, once the detent release lever is actuated a detent switch in the latch assembly provides a signal to a microcontroller indicating that the fork bolt is in the unlatched position. Accordingly, the polarity to the motor is reversed and the carrier nut is driven from the unlatched position to the home position. Here, the carrier nut is rotated until the drive pin or nut pin contacts side wall 23 thus causing rotation of the carrier nut before linear movement and causing the drive lug to no longer be engaged with the detent release lever. Then the carrier nut moves from the unlatched position to the home position wherein the cam surface 71 contacts the micro-switch and stops the motor when the carrier nut is in the home position and is now ready to move again towards the latched configuration.
Referring now to
Once an unlatch command is received, the drive pin travels from position 3 to position 4 (e.g., second home position to unlatched) and once the detent switch indicates the fork bolt is in the unlatched position, the polarity to the motor is reversed and the carrier nut and the drive pin rotate until the opposite side of the opening is contacted and then the carrier nut translates towards the first home position wherein the power is shut off once the cam surface of the carrier nut contacts the micro-switch and the carrier nut stays in the first home position until a latch command is received by the cinching latch assembly controller. As illustrated, two home positions are provided one after latching and one after unlatching wherein the carrier nut is rotated to allow the drive lug to no longer engage the cinching lever or the detent release lever and be positioned to engage the detent release lever or the cinching lever. Moreover, and as discussed above and in the event of power loss at any position the carrier nut is capable of being rotated to move the location of the drive lug without requiring linear translation of the carrier nut.
It is understood that a controller operating in response to a computer program may implement the processing of the above description. In order to perform the prescribed functions and desired processing, as well as the computations therefore, the controller may include, but not be limited to, a processor(s), computer(s), memory, storage, register(s), timing, interrupt(s), communication interfaces, and input/output signal interfaces, as well as combinations comprising at least one of the foregoing.
As described above, algorithms for implementing exemplary embodiments of the present invention can be embodied in the form of computer-implemented processes and apparatuses for practicing those processes. The algorithms can also be embodied in the form of computer program code containing instructions embodied in tangible media, such as floppy diskettes, CD-ROMs, hard drives, or any other computer-readable storage medium, wherein, when the computer program code is loaded into and executed by a computer and/or controller, the computer becomes an apparatus for practicing exemplary embodiments of the invention. Existing systems having reprogrammable storage (e.g., flash memory) that can be updated to implement various aspects of command code, the algorithms can also be embodied in the form of computer program code, for example, whether stored in a storage medium, loaded into and/or executed by a computer, or transmitted over some transmission medium, such as over electrical wiring or cabling, through fiber optics, or via electromagnetic radiation, wherein, when the computer program code is loaded into and executed by a computer. When implemented on a general-purpose microprocessor, the computer program code segments configure the microprocessor to create specific logic circuits.
These instructions may reside, for example, in RAM of the computer or controller. Alternatively, the instructions may be contained on a data storage device with a computer readable medium, such as a computer diskette. Or, the instructions may be stored on a magnetic tape, conventional hard disk drive, electronic read-only memory, optical storage device, or other appropriate data storage device. In an illustrative embodiment of the invention, the computer-executable instructions may be lines of compiled C++ compatible code.
In an exemplary embodiment the controller includes logic for evaluating signals from the plurality of sensors to determine when and in what direction to operate the motor.
In the event that power is lost to reversible motor 12, cinching latch assembly 2 includes a manual override. More specifically, in the event of a mechanical failure, or power is lost at reversible motor 12, an access panel (not shown) is opened to provide access to override arm 83. Once accessible, override arm 83 is pivoted to release detent release lever 73 which, in turn, releases fork bolt 67.
Moreover, and in the event power is lost when the drive pin is in between positions 1 and 2 or 3 and 4 the same is simply rotated within the housing to disengage the drive lug from either the cinching lever or the detent release lever.
At this point it should be appreciated that the above-described cinching latch assembly can be easily operated in the event of a mechanical or electrical failure to ensure that an associated vehicle panel can be freely shifted between open and closed positions without requiring the latch to be reset. Moreover, the use of cam surfaces reduces the overall number of operating parts of the cinching latch assembly resulting in manufacturing and cost efficiencies.
While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the appended claims.
This application claims the benefit of U.S. Provisional Patent Application Ser. No. 60/847,517 filed Sep. 27, 2006, the contents of which are incorporated herein by reference thereto.
| Number | Date | Country | |
|---|---|---|---|
| 60847517 | Sep 2006 | US |
