Patent Publication Number: US-10316551-B2

Title: Apparatus and method for preventing undesired latch release

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/925,853, filed Jan. 10, 2014, the entire contents of which are incorporated herein by reference thereto. 
    
    
     TECHNICAL FIELD 
     Exemplary embodiments of the present invention relate generally to latch mechanisms and, more particularly, to operation of latch mechanism during and/or after application an excessive force to the latch and/or a vehicle the latch is secured to. 
     BACKGROUND 
     A vehicle frequently includes displaceable panels such as doors, a hood, a trunk lid, a hatch, and the like which are affixed for hinged or sliding engagement with the vehicle structure of a vehicle body. Cooperating systems of latches and strikers are typically provided to ensure that such panels remain secured in their fully closed position when a panel is closed. 
     A door latch typically includes a fork bolt or claw that is pivoted between an unlatched position and a primary latched position when the door is closed to latch the door in the closed position. The claw is typically held in the primary latched position by a detent or pawl that pivots between an engaged position and a disengaged position. The pawl is spring biased into the engaged position and thus, holds the claw in the primary latched position when in the engaged position and releases the claw when it is moved to the disengaged position so that the door can be opened. The claw is pivoted to the primary latched position by a striker attached to, for example, an associated door jamb when the door is closed. Once in the primary latched position, the pawl engages the claw to ensure the assembly remains latched. 
     In order to open a vehicle door, an outer door handle is coupled to a release lever by a cable. Application of an extreme force to the vehicle panel and/or the corresponding latch secured thereto may be transferred to the release cable, thereby causing the release lever to actuate the pawl and open the latch and/or unlatch the panel from the vehicle. For example, during a vehicle crash door sheet metal or other parts may shear and may create a pulling force on the release cable and thus manipulate the release lever which is operatively coupled to other components of the latch. 
     Accordingly, it is desirable to provide a latch wherein unintended movement of the release lever is limited to prevent undesired opening of a vehicle panel and/or its associated latch. 
     SUMMARY OF THE INVENTION 
     In accordance with an embodiment, a latch is provided. The latch having: a claw pivotally mounted to the latch for movement between an unlatched position and a latched position; a pawl pivotally mounted to the latch for movement between an engaged position and a disengaged position, wherein the pawl prevents movement of the claw into the unlatched position from the latched position when the pawl is in the engaged position and wherein the claw is able to move into the unlatched position from the latched position when the pawl is in the disengaged position; a release lever pivotally mounted to the latch for movement between a first position and a second position and operatively coupled to the pawl, wherein movement of the release lever from the first position to the second position moves the pawl from the engaged position to the disengaged position; and a housing having a back plate, each of the claw, the pawl, and the release lever being rotatably mounted to the back plate, the back plate including an back plate leg configured to transform from a un-deformed position to a deformed position in response to an impact applied to the latch, wherein the back plate leg interferes with movement of the release lever from the first position to the second position when it is in the deformed position. 
     According to another embodiment of the present invention, a method of preventing undesired opening of a latch when a force is applied to the latch. The method including the steps of: transforming a back plate leg formed integrally with a back plate of the latch from a coplanar position with respect to the back plate to a deformed non-coplanar position with respect to the back plate in response to an impact applied to the latch; and inhibiting rotation of a release lever of the latch from a first non-actuated position to a second actuated position when the back plate leg is in the deformed position. 
     In yet another embodiment, a vehicle latch is provided. The vehicle latch having: a back plate; a pawl rotatably mounted to the back plate; a claw rotatably mounted to the back plate, wherein the pawl cooperates with the claw to allow or inhibit movement of the claw based upon a position of the pawl; an outside release lever rotatably mounted to the back plate, the outside release lever being operatively coupled to an outside release handle via a cable, wherein actuation of the outside release handle causes the outside release lever to move from a first position to a second position via the cable and wherein movement of the outside release lever from the first position to the second position causes a corresponding movement of the pawl; and wherein the back plate further comprises a deformable member proximate to the outside release lever, the deformable member when in an un-deformed position is coplanar with the back plate and does not interfere with movement of the pawl and when the deformable member is in a deformed position, the deformable member prevents movement of the release lever from the first position to the second position. 
     The above-described and other features and advantages of the present invention will be appreciated and understood by those skilled in the art from the following detailed description, drawings, and appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: 
         FIG. 1  is a perspective view of portions of a latch assembly; 
         FIG. 2  is a perspective view of an interior of a latch assembly according to an embodiment of the invention; 
         FIG. 3  is another perspective view of an interior of a latch assembly according to an embodiment of the invention; and 
         FIG. 4  is a perspective view illustrating movement of the release lever. 
     
    
    
     DETAILED DESCRIPTION 
     Reference is made to the following U.S. Pat. Nos. 5,277,461; 5,308,130; 6,053,543; and 8,398,128, the entire contents each of which are incorporated herein by reference thereto. 
     Referring now to the FIGS., an example of a latch or latch assembly  20  is illustrated.  FIG. 1  illustrates portions of the latch or latch assembly  20 . This latch  20  may be integrated into a component of a vehicle, such as the vehicle door, trunk, or any other operable component for example. The latch  20  includes a multi-piece enclosure comprising a housing  22  connected to a back plate  24  ( FIGS. 2-4 ). The housing  22  and back plate  24  are commonly held together by at least a first and second pivot pin  26 ,  28 , each of which is inserted through aligned holes (not shown) in the housing  22  and back plate  24 . 
     The latch  20  additionally includes a fork bolt or claw  30  and a cooperating detent or pawl  40  ( FIG. 1 ). The claw  30  and pawl  40  are pivotally mounted to the back plate  24  by the first and second pivot pin  26 ,  28 , respectively. The claw  30  is configured to rotate between an open, unlatched position and a closed, latched position. The pawl  40  cooperates with the claw  30  in a known manner to retain the claw  30  in the closed position or release the claw  30  for return to the open position. That is, the pawl  40  pivots between a first, engaged position and a second, disengaged position. 
     The latch  20  may be integrated into a portion of a vehicle, such as the vehicle structure (not shown) for example, such that the claw  30  moves between the open position and the closed position when a door, window, lift gate, etc. is opened and closed and the claw engages a striker (not shown) attached to the door, window, lift gate, etc. Alternatively, the latch  20  may be secured to the door, window, lift gate etc. and the striker (not shown) may be secured to the vehicle structure at an opening into which the door, window, lift gate etc. is received. Cooperation of the claw  30  and striker (not shown) is well known and need not be described in detail. 
     In one embodiment, the claw  30  may be biased into the open position by a biasing mechanism (not shown), such as by a torsion spring for example, and the pawl  40  may be similarly biased into engagement with the claw  30  by another biasing mechanism (not shown). The claw  30  has a slot or throat  32  for receiving and retaining the striker (not shown) located on a complementary vehicle component. In an exemplary embodiment, the claw  30  includes at least a primary shoulder  34 . The pawl  40  includes a first leg  42  that positively engages the primary shoulder  34  of the claw  30  to hold the claw  30  against a biasing force in a latched position. 
     When the claw  30  rotates between an open, unlatched position and a closed, latched position, a portion  36  of the claw  30  contacts the first leg  42  of the pawl  40  and applies a rotational force thereto in a direction opposite the biased direction of rotation of the pawl  40 . This rotational force causes the pawl  40  to rotate about pivot pin  28  such that the first leg  42  of the pawl  40  pivots out of engagement with the claw  30 . The biasing force of the biasing mechanism (not shown) causes the first leg  42  of the pawl  40  to rotate back into engagement with the claw  30  to contact the primary shoulder  34 . 
     Referring now to  FIGS. 2-4 , a release lever or outside release lever  50  is similarly mounted about the pivot pin  26  for rotation relative to the back plate  24  between a first or neutral position and a second or actuated position. In one embodiment, a first end  52  of the release lever or outside release lever  50  is operably coupled to a handle (illustrated schematically at  54 ), such as an external or exterior handle mounted on an exterior of a vehicle or vehicle door for example, via a release cable  53  (illustrated by the dashed lines) that passes through a cable guide or cable end fitting  56  secured to the latch  20 . Upon operation of the handle  54 , a force is transmitted to the first end  52  of the release lever  50  by for example movement of the release cable in the direction of arrow  51 , which in turn causes the release lever or outside release lever  50  to pivot from a first position, in a direction indicated by arrow A, to a second actuated position (See at least  FIG. 4 ). As the release lever  50  rotates from the first position to the second position, the release lever  50  is configured to engage a portion (not shown) of the pawl  40  and thus rotate the pawl from the engaged position to the disengaged position. As a result, the rotation of the release lever  50  causes the first leg  42  of the pawl  40  to disengage from the primary shoulder  34  of the claw  30  thereby allowing the claw  30  to rotate open to an unlatched position. 
     The back plate  24  is configured to provide structural support to the latch  20  and is formed from a robust material, such as steel for example. Of course, other suitable materials are contemplated in accordance with various embodiments of the present invention. The back plate  24 , as illustrated in  FIGS. 2-4 , includes a back plate leg or member  60  integrally formed with the back plate  24  at a first end  62 , proximate to the first end  52  of the release lever  50 . A first side  64  of the back plate leg  60  is separated from an adjacent portion of the back plate  24  by a first gap  66 , and a second, opposite side  68  of the back plate leg  60  is separated from an adjacent portion of the back plate  24  by a second gap  70 . The first gap  66  and the second gap  70  may be generally equivalent in size, or alternatively, may vary in size. During normal operation of the latch  20 , the back plate leg  60  is substantially coplanar with the back plate  24 . 
     The back plate leg or member  60  is configured to transform from an un-deformed position coplanar with the back plate  24  to a deformed position when the energy of an impact, such as generated during a collision of the vehicle to which the latch  20  is mounted, is applied to the back plate  24 . In response to the impact, the back plate leg or member  60  may bend or deform about its first end  62 , out of the plane of the back plate  24  in the direction of arrow  55  towards the first end  52  of the release lever  50 . As an end  57  of the leg or member  60  moves upward in the direction of arrow  55  it may be repositioned into the position illustrated at least by the dashed lines in  FIG. 2 . At this position, the first side  64  of leg or member  60  is in a position to contact a surface  59  of the release lever  50  and inhibit movement of the release lever  50  in the direction of arrow A towards the second actuated position. Thus, when in the deformed position (e.g., out of plane with back plate  24 ) the back plate leg or member or deformable member  60  will prevent or inhibit movement of the outside release lever  50  from the first position towards the second position in the direction of arrow A. 
     The size, shape, and orientation of the back plate leg  60  may be selected to optimize the deformation of the back plate leg  60  based on a position and magnitude of the force applied to the latch  20 . Still further, the configuration and/or location of the back plate leg or member or deformable member  60  may be varied or adjusted to be deformed based upon different types of impacts applied to the latch  20  and/or back plate leg, member or deformable member  60 . 
     As illustrated in at least  FIGS. 2-4 , the back plate leg or member  60  may extend to a peripheral edge of the back plate  24  and in one embodiment, the end  57  may comprising an upturned end portion located proximate to the peripheral edge of the back plate  24 . Alternatively, the back plate leg or member  60  may not comprise an upturned end portion and/or may not extend to the peripheral edge of the back plate  24 . In some embodiments, at least a portion of the upturned end portion  57  may comprise a portion or alternatively is the portion of the first side  64  that contacts the release lever  50  when the back plate leg  60  is in the deformed position and the release lever moves from the first position towards the second position. In other embodiments, the portion of the first side  64  that contacts the release lever  50  when the back plate leg  60  is in the deformed position may not include the upturned end portion  57  (e.g., the contact portion may include a portion of the first side  64  that does not include the upturned end portion). It being understood that various embodiments of the present invention contemplate numerous configurations of the back plate leg or member  60  that contacts the release lever when it is in the deformed position. 
     When in the deformed position, the back plate leg or member  60  is configured to interfere with the rotation of the release lever  50  to either stop or slow the rotation of the release lever  50  toward the second actuated position. As mentioned above an impact or excessive force to the vehicle and/or latch  20  may sometimes apply a force to the release cable  53  (illustrated by the dashed lines) due to an element or elements being deformed during this impact or application of excessive force thereby causing a pulling force on the release cable  53  in the direction of arrow  51 , which in turn may cause the release lever  50  to rotate in the direction of arrow A from a neutral or first position towards the second or actuated position. However and by locating the back plate leg or member or deformable member  60  in the back plate  24  the element or elements or additional elements being deformed during this impact or application of excessive will move the back plate leg or deformable member  60  into a deformed position that will be in the path of travel of the release lever  50  and thus, the back plate leg or member or deformable member  60  prevents the rotation of the release lever towards the second or actuated position and thus prevents opening of the latch  20  via movement of outside release lever or lever  50 . The element or elements or additional elements being deformed during an impact or application of excessive force to the vehicle and/or latch may be the same ones that deform the back plate leg or member or deformable member  60  as well as apply the force to the release cable  53  in the direction or arrow  51 . Alternatively, different elements or additional elements deformed during an impact or application of excessive force to the vehicle and/or latch will deform the back plate leg or deformable member  60  as opposed to those that apply the force to the release cable in the direction or arrow  51 . 
     It being understood that while back leg or member or deformable member  60  is in the blocking position, the latch  20  may still be opened by an inside release lever (not shown) that is operably coupled to an inside release handle (not shown). The inside release handle being mounted on an interior surface of the vehicle. In other words and in one embodiment, leg or member or deformable member  60  may only interfere with the operation of the release lever or outside release lever  50  coupled to the outside release handle  54  (located on an exterior surface of the vehicle) when it is in the blocking position illustrated by for example, the dashed lines in  FIG. 2 . 
     It being understood, that as the release lever  50  is rotated or moved from the first or unactuated position to the second or actuated position in the direction of arrow A due to operation of the handle  54  and movement of cable  53  in the direction of arrow  51  at least a portion of the release lever  50  will have to travel past the back plate leg or member  60  (See at least  FIG. 4 ), which is possible when the back plate leg or member  60  is co-planar with respect to the back plate  24  (See at least the dashed lines in  FIG. 4 ). Thus, opening of the latch  20  is possible via movement of the release lever  50  when the back plate leg or member  60  is co-planar with the back plate  24 . In other words, desired operation of the latch  20  is not interfered with when the back plate leg or member  60  is co-planar or in a non-blocking position with respect to the back plate  24 . 
     By including a back plate leg or member  60  adjacent the outside release lever or release lever  50 , desired opening of the latch  20  or movement of the outside release lever or release lever  50  during a vehicle collision is reduced as the back plate leg or member  60  can be deformed into a non-coplanar blocking position with respect the back plate  24 . 
     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.