Abstract:
An actuator configured to actuate a member. The actuator optionally including capabilities for storing and releasing kinetic energy. The actuator being suitable for use in any number of environments, including but not limited to facilitating seat folding operations.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a continuation of U.S. application Ser. No. 12/397,608 filed Mar. 4, 2009, which is a divisional of U.S. application Ser. No. 11/472,203 filed Jun. 21, 2006, now U.S. Pat. No. 7,547,070 B2 on Jun. 16, 2009, the disclosures of which are incorporated in their entirety by reference herein. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to seat fold actuators. 
       BACKGROUND 
       [0003]    Actuators and triggers are devices that cause an apparatus to operate. Latches are devices that are used to grasp or lock an object, as with a catch and a lever, or the like. An actuator may be used to release or engage a latch. Some actuators may be remotely connected to a latch to allow for operation of the latch from a distance. 
         [0004]    Latches are used in a wide variety of applications. For example, latches may be provided as a part of a machine, on building doors or windows, or in vehicles. Latches that can be reset have the advantage that they can be used repeatedly. One way to provide a latch that can be reset is to provide an actuator that operates a motor and gear reducer to release the latch by forward rotation of the motor and reset the latch by reverse rotation of the motor. While this approach is effective, the cost of a motor and gear reducer may be uneconomical in many applications. 
         [0005]    In some applications, it may be desirable to provide a manual actuator and a power actuator for a latch that may be alternatively used to operate the latch. Dual mode actuators may be provided to allow a latch to be manually operated or power operated. One problem with such dual actuation latches is that one mode of actuation may interfere with the other mode. In addition, resetting the dual mode actuator may be complicated if both modes of actuation are not accommodated by the reset mechanism. 
         [0006]    One exemplary application for a dual mode remotely actuated latch is a vehicle seat back folding apparatus. Vehicle seat backs may be folded over the seat base to facilitate ingress and egress. Prior art actuators have been developed that use a motor that drives a gear reducer in one direction to release a latch and driven in the opposite direction to reset the actuator for reuse after the latch is engaged. Seat folding latches may also be specified to be manually actuated in the event that a user wishes to operate the latch manually or if power is not available for the power actuation system. While these types of systems have been developed, the cost of the motor and gear reducer may make such systems uneconomical. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0007]    The present invention is pointed out with particularity in the appended claims. However, other features of the present invention will become more apparent and the present invention will be best understood by referring to the following detailed description in conjunction with the accompany drawings in which: 
           [0008]      FIG. 1  illustrates a vehicle seat in accordance with one non-limiting aspect of the present invention; 
           [0009]      FIG. 2  illustrates one way of connecting a seat back to a seat base in accordance with one non-limiting aspect of the present invention; 
           [0010]      FIG. 3  illustrates a trigger assembly in more detail in accordance with one non-limiting aspect of the present invention; 
           [0011]      FIG. 4  illustrates a folded over seat position in accordance with one non-limiting aspect of the present invention; 
           [0012]      FIG. 5  illustrates a flipped forward seat position in accordance with one non-limiting aspect of the present invention; 
           [0013]      FIG. 6  illustrates an assembly view drawing of the trigger assembly in accordance with one non-limiting aspect of the present invention; 
           [0014]      FIGS. 7   a - 9   b  illustrate operation of the trigger assembly in accordance with one non-limiting aspect of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0015]    As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for teaching one skilled in the art to variously employ the present invention. 
         [0016]    Referring to  FIG. 1 , a vehicle seat  10  is illustrated that has a seat back  12 , a seat base  14 , and a trigger assembly  15 . An actuator  18  is illustrated as being attached to the seat base  14 . However, it should be understood that the actuator  18  could be secured to another location on the vehicle or seat support structure. A latch lever  20  is connected to the actuator  18  by a Bowden cable  22 , or link. The Bowden cable  22  includes a sleeve  24  that encloses a wire  26  so that the wire  26  is axially moveable relative to the sleeve. 
         [0017]    The wire  26  connects to a trigger plate  27  such that actuation of the wire  26  in the downward direction causes the trigger plate  27  to move in a counter-clockwise direction and to over come spring biasing provided by a chaser spring  29  in an opposite, locking direction. A power plate wire  31  connects a power plate  33  to the latch lever  20  such that a power plate spring  25  instigates counter-clockwise rotation of a power plate  33  in an actuation direction in order to cause the latch lever  20  to pivot in similar counter-clockwise manner about pivot  46 . A reset wire  35  connects to power plate  33  and can be tensioned with rotation of the seat back  14  in order to facilitate resetting the power plate  33 , as described below in more detail. 
         [0018]    First and second mirroring wires  37  and  39  actuate mirroring features on an opposite side of the seat  10  so as to perform mirroring operations associated with actuating a mirroring latch lever (not shown). The mirroring operations essentially facilitate releasing the opposite side of the seat in a manner similar to the illustrated side of the seat, but optionally without a second trigger assembly  15 . 
         [0019]    Referring to  FIG. 2 , one type of hinge mechanism is shown in greater detail in an exploded perspective view that shows one way of connecting the seat back  12  to the seat base  14 . It should be understood that other types of hinge mechanisms may be adapted to include the latch actuator system of the present invention. A pair of seat base plates  36  are connected to a seat back support bracket  38  by means of a pivot pin  40 . Pivot pin  40  is received in a hole  42  that extends through the seat base plates  36 , seat back support bracket  38  and bracket  32 . A spring bracket  44  retains seat spring  30  and interconnects the seat spring  30  to the pivot pin  40 . The latch lever  20  shown in  FIG. 1  is connected to a lever pivot pin  46 . 
         [0020]    The latch lever  20  is secured to the lever pivot pin  46  which is in turn secured to a latching follower  56 . The seat back support bracket  38  includes a step  58  that is engaged by the latching follower  56  when the seat is in its latched position. After the seat is unlatched, the latching follower  56  follows an arcuate cam surface  60  on the support bracket  38  as the support bracket  38  pivots about pivot pin  40  into a position where a seat back  12  is folded over the seat base  14 . 
         [0021]    Referring now to  FIGS. 3-4 , the trigger assembly  15  is described with reference to the embodiment of the invention described above with reference to  FIGS. 1 and 2 .  FIG. 3  is an enlarged illustration of a portion of the apparatus described with reference to  FIG. 1  that is within the oval denoted  FIG. 3  in  FIG. 1 . In  FIG. 3 , the apparatus is shown in its latched condition with the seat back support bracket  38  held in a vertical, rearwardly inclined orientation and is fixed relative to the seat base plates  36 . In this position the latch lever  20  is in its retained position. 
         [0022]    A cable sleeve bracket  64  secures the sleeve  24  to seat base  14  or other supporting structure. A handle  70  is provided at the opposite end of the latch lever  20  from the cable sleeve bracket  64 . The handle  70  is intended to be grasped directly or indirectly by a person for manually manipulating the latch lever  20 . The latch is lifted to cause the latching follower  56  to clear the step  58  and seat back  12  to move forwardly with the force applied by the seat spring  30 , thereby allowing the seat back  12  to rotate to a folded over position as the latching follower  56  follows the arcuate cam surface  60 . 
         [0023]    While not shown, the handle  70  may be provided with an enlarged handle cover to make the handle  70  easier to grasp and to provide a finished appearance. As shown in  FIG. 3 , a slack portion  72  may be provided in the wire  39  to allow the handle  70  to be easily lifted without encountering resistance from the seat spring  30  mirroring element (not show) to which the wire  39  is connected. The extent of slack is somewhat exaggerated as shown for illustrative purposes. 
         [0024]    Referring to  FIG. 4 , actuation of the latch  20  is illustrated in either a manual or power mode. In the manual mode the lever  20  may be manually grasped and moved from the position shown in phantom lines to the position shown in solid lines. When the latch lever  20  is lifted, the latching follower  56  disengages the step  58  as previously described. Alternatively, the latch may be power actuated upon triggering the actuator  18 . The actuator  18  may comprise a shape memory alloy trigger, a solenoid or other actuator that is capable of exerting a tensioning force on wire  26 . In the embodiment illustrated in  FIG. 4  the actuator  18  exerts a pulling force on the cable that pulls the trigger plate  27  in a counter-clockwise direction. This movement causes the trigger assembly  15  to move from a loaded position to a fired position wherein the trigger plate  27  triggers the power plate  33  to pull upwardly on the wire  31 , which thereby pulls upwardly on the latch lever  20  to actuate the latch lever  20  from the retained position to the released position. 
         [0025]    When the lever actuator  20  is rotated about the pivot pin  46  from the retained position to the released position the latching follower  56  disengages the step  58  as previously described. When the latching follower  56  clears the step  58  the seat back support bracket  38  moves from the position shown in phantom lines in  FIG. 4  along the curved arrow path to the position shown in solid lines in  FIG. 4 . The seat spring  30  drives the seat back  12  and its associated support bracket  38  into the folded over position. 
         [0026]    Optionally, as shown in  FIG. 5 , the seat  10  may automatically flip forward to the illustrated stadium seat position (folded forward position) once the seat back  12  reaches the folded over position. A seat base actuator system  67 , or other arrangement, may be included to facilitate such movement. The seat base actuator system  67  may include a cable or other feature (not shown) connected to the seat back  12 , support  38 , or other feature in the system  10  such that actuation of the seat back  12  to the folded down position allows the seat base actuator system  67  to then flip the seat back  12  and seat base  14  to the stadium or flipped forward position shown in  FIG. 5 . 
         [0027]    As the seat back  12  folds to or is folded up from the folded position (fold flat, flipped forward, etc.), the reset cable  35  tightens from its slack position to rotate the power plate  33  from its released position ( FIG. 4 ) to its loaded position ( FIG. 3 ). This movement resets the trigger assembly  15  such that the power plate  33  is loaded and ready to trigger rotation of the lever latch  20  in response to triggering of the trigger plate  27 . A reset mechanism  68  may be included on the seat base actuator system  67  to facilitate tensioning the reset cable  35  or some other mechanism may be similarly employed. 
         [0028]      FIG. 6  illustrates an assembly view drawing of the trigger assembly  15  in accordance with one non-limiting aspect of the present invention. The trigger assembly  15  may include the trigger plate  27  on one side of a reference plate  80  and the power plate  33  on an opposite of the same such that both plates are configured to rotate coaxially about a central portion  82  of the reference plate  80 . Each of the reference plate  80 , trigger plate  27 , and power plate  33  may include common apertures  86 - 90  for receiving a ball bearing  94 - 98 . The apertures  86 - 90  on each plate may be arranged relative to each other such that they cooperate to control actuation of the trigger assembly  15  from the loaded to fired positions. 
         [0029]    A chaser spring  29  may be attached to the reference plate  80  and the trigger plate  27  such that the chaser spring  29  causes the trigger plate  27  to rotate in a clockwise direction relative to the reference plate  80 . A power spring  102  may be attached to the reference plate  80  and the power plate  33  such that the power plate spring  25  causes the power plate  33  to rotate in a counter-clockwise direction relative to the reference plate  80 . As described below in more detail, the counter-clockwise rotation of the power plate spring  25  may be used to actuate the power plate  33  and the connected latch lever  20  from the retained position (loaded position) to the released position (fired position). Similarly, the clockwise rotation of the chaser spring  29  may be used to return the trigger plate  27  from the fired position to the loaded position. 
         [0030]      FIGS. 7   a - 9   b  illustrate the interaction of ball bearing  94  with one of the corresponding apertures  86  in accordance with one non-limiting aspect of the present invention.  FIGS. 7   a - 7   b  relate to the loaded position,  FIGS. 8   a - 8   b  relate to the fired position, and  FIGS. 9   a - 9   b  related to returning from the fired to loaded position. The loaded position includes the trigger assembly  15  storing kinetic energy associated with a cocked or otherwise flexed power plate spring  25  such that the ball bearing  94  is disposed partially within the aperture  86  of the power plate  33  such that the power plate  33  is unable to move in the counter-clockwise direction. The fired position relates to the releasing of the stored energy and the counter-clockwise rotation of the power plate  33 , i.e., the releasing of the power plate spring  25  to rotate the power plate  33  and thereby actuate the latch lever  20 . 
         [0031]    From the loaded position, the fired position may be obtained with movement of the trigger plate  27  in a counter-clockwise direction, such as with actuation of the trigger wire  26 . This movement aligns the aperture  86  of the trigger plate  27  with the corresponding aperture  86  of the reference plate  80 . Because the power plate  33  is under force from the power plate spring  102 , the power plate is urged against the ball bearing  94  such that once the trigger plate  27  is aligned with the reference plate  80 , the ball bearing  95  travels along an incline  106  and into the apertures  86  of the reference plate  80  and trigger plate  27 , thereby freeing the power plate  33  to move in the counter-clockwise direction, which as described above actuates the latch lever  20  from the retained position to the released position. 
         [0032]    From the fired position, and once tensioning on the trigger wire  26  is removed or decreased below the force of the chaser spring  29 , the chaser spring  29  forces the trigger plate in a clockwise direction such that an incline  108  on the trigger plate  27  forces the ball bearing  94  in a downward direction, once the power plate  33  is properly aligned to receive the ball bearing  94 . The power plate  33  may receive the ball  94  if it is reset, i.e., returned to the positioning shown in  FIG. 7   a  that permits the ball bearing  94  to be disposed within a portion of the power plate  33 . The power plate  33  may be reset in any manner, including tensioning or other tightening of the reset wire  35 , such as by the flipping of the seat back  14  and/or seat base  12  described above. 
         [0033]    In the illustrated embodiments, the seat backs  12  are disclosed as examples. The seat back may be more generically referred to as a latched member. Other types of latched members may include a seat base, a combination of a seat base and seat back, a headrest, a flat screen video display, a compartment cover, a glove box door, a hood, a deck lid, a seat back tilt adjustment armature, and the like. Another example in which more than one latched member is controlled by the latch and trigger is that of a seat back that folds over a seat base, and then the folded over seat is tumbled forward for storage, ingress, and egress. With any of those arrangements the trigger is electrically actuated and a movement of the latched member is executed to reset the trigger. 
         [0034]    As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The present invention fully contemplates its application in any number of environments, including those associated with U.S. patent application Ser. No. 11/278,295, filed Mar. 3, 2006, the disclosure of which is hereby incorporated in its entirety. The figures are not necessarily to scale, some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for the claims and/or as a representative basis for teaching one skilled in the art to variously employ the present invention. 
         [0035]    While exemplary embodiments are described above, it is not intended that these embodiments describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention. Additionally, the features of various implementing embodiments may be combined to form further embodiments of the invention.