Abstract:
A latch is provided including a fork bolt configured to rotate between an unlatched position and a latched position. A detent is configured to cooperate with the fork bolt. At least one of the fork bolt and the detent includes a resilient absorption mechanism. The resilient absorption mechanism is configured to deform upon impact and decelerate the rotation of either the fork bolt of the detent respectively. The latch also includes a housing and a stop tab protruding from the housing. The stop tab is configured to engage a complementary portion of the fork bolt with in a latched position to limit further rotation thereof.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/760,274 filed Feb. 4, 2013, the contents of which are incorporated herein by reference thereto. This application also claims the benefit of U.S. Provisional Patent Application Ser. No. 61/760,276 filed Feb. 4, 2013, the contents of which are also incorporated herein by reference thereto. 
     
    
     TECHNICAL FIELD 
       [0002]    Exemplary embodiments of the present invention relate generally to latches and, more particularly, to latches for vehicles. 
       BACKGROUND 
       [0003]    Latches are used to restrain the movement of one member or element with respect to another. For example, door latches restrain the movement of a door with respect to a surrounding door flame. The function of such latches is to hold the door secure within the frame until the latch is released and the door is free to open, Existing latches typically have mechanical connections linking the latch to actuation elements such as handles which can be actuated by a. user to release the latch. Movement of the actuation elements is transferred through the mechanical connections that cause the latch to release. The mechanical connections can be one or more rods, cables, or other suitable elements or devices. 
         [0004]    Latch sound quality can enhance or detract from the overall perception of quality by an end user about the construction of the vehicle. For example, good sound quality may imply solid construction, smooth operation, and thoughtfulness of design. As a result, vehicle manufacturers are placing more emphasis on the ability of the door latch to absorb the noise emissions that may occur during a closing event. Sound quality metrics, such as minimal loudness and frequency content for example, are affected by many variables including the profile geometry, small features, and material selection of the components of a latch mechanism. 
         [0005]    Accordingly, while existing vehicle latch mechanisms are suitable, the need for improvement remains, particularly in providing a latch mechanism having improved noise dampening and energy absorption. 
       SUMMARY OF THE INVENTION 
       [0006]    In accordance with one embodiment, a latch is provided including a fork bolt configured to rotate between an unlatched position and a latched position. A detent is configured to cooperate with the fork bolt. At least one of the fork bolt and the detent includes a resilient absorption mechanism. The resilient absorption mechanism is configured to deform upon impact and decelerate the rotation of either the fork bolt of the detent respectively. The latch also includes a housing and a stop tab protruding from the housing. The stop tab is configured to engage a complementary portion of the fork bolt with in a latched position to limit further rotation thereof. 
         [0007]    According to another embodiment of the present invention, a housing for a latch rotatable between an unlatched position and a latched position is provided including an opening for receiving a striker wire. The opening is complementary to a throat of the latch. The opening is sized such that when the striker wire is inserted into the opening, the striker wire does not contact the housing. 
         [0008]    According to yet another embodiment of the present invention, a latch rotatable between an unlatched position and a latched position is provided including a resilient bumper. The bumper includes an upper contact portion arranged generally perpendicular to an elongated lower portion. The bumper is configured to receive a portion of a striker wire between the upper contact portion and the elongated lower portion to absorb noise and vibrations from the striker wire. 
         [0009]    According to yet another embodiment of the present invention, a latch is provided including a fork bolt rotatable between an unlatched position and a latched position. A detent is configured to cooperate with the fork bolt. At least one noise-reducing component is configured to absorb noise and vibration generate by receipt of the striker wire within the latch. 
         [0010]    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 
         [0011]    Embodiments of the present invention will now be described, by way of example only, with reference to the accompanying drawings in which: 
           [0012]      FIG. 1  is a front view of a latch mechanism in a primary latched position according to an embodiment of the invention; 
           [0013]      FIG. 2  is a front view of a latch mechanism in a secondary latched position according to an embodiment of the invention; 
           [0014]      FIG. 3  is a front view of a housing of a latch mechanism in a primary latched position according to an embodiment of the invention; 
           [0015]      FIG. 4  is a perspective view of the housing of a latch mechanism according to an embodiment of the invention; 
           [0016]      FIG. 5  is a perspective view of a backside of a stop tab of the latch mechanism according to an embodiment of the invention; 
           [0017]      FIG. 6  is a front view of a stop tab of the latch mechanism according to an embodiment of the invention; 
           [0018]      FIG. 7  is a front view of a bumper of a latch mechanism according to an embodiment of the invention; and 
           [0019]      FIG. 8  is a front view of the bumper when the latch mechanism is a secondary latched position according to an embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0020]    With reference to all of the FIGS., an exemplary latch  10  having improved sound performance is illustrated. The latch  10  is movable between a latched position and an unlatched position, and is disposed within a housing  12 . The latch  10  may be integrated into a component of a vehicle, such as the vehicle structure adjacent a lift gate, trunk, door, or any other operable component for example. 
         [0021]    The latch  10  includes a fork bolt  30  and a cooperating detent lever  50  for maintaining the fork bolt  30  in the latched position. The fork bolt  30  and the detent lever  50  are each pivotally mounted to the housing  12  of the latch  10  by a stud (not shown) positioned in holes  14 ,  16  respectively. The fork bolt  30  is biased in the direction of arrow F by a first biasing mechanism (not shown), and the detent lever  50  is biased in the direction of arrow D, into engagement with the fork bolt  30 , by a second biasing mechanism (not shown). In one embodiment, the first and second biasing mechanisms are coil or torsion springs. The fork bolt  30  has slot or throat  32  for receiving and retaining a striker  80  (see  FIGS. 2 ,  4 ), such as a wire-loop striker for example, located on a complementary vehicle component, such as a lift gate or trunk. The fork bolt  30  also includes a primary shoulder  40  and an intermediate or secondary shoulder  34 . The secondary shoulder  34  of the fork bolt  30  includes a contact surface  38  configured to contact an engagement surface  54  of the detent lever  50  when rotating between an unlatched and a latched position 
         [0022]    The detent lever  50  includes a sector-shaped catch  52  configured to positively engage a surface  42 ,  36  of each of the primary and secondary shoulders  40 ,  34  to hold the fork bolt  30  against the bias of the first biasing mechanism in either a primary latched position ( FIG. 2 ) or secondary latched position ( FIG. 1 ) respectively. In one embodiment, a portion of the detent lever  50  is coupled to a release mechanism RM, illustrated schematically in  FIG. 1 . The aforementioned fork bolt  30  and detent lever  50  are illustrated as a non-limiting embodiment. Numerous other types or configurations of the fork bolt  30  and detent lever  50  are considered to be within the scope of an exemplary embodiment of the present invention. 
         [0023]    As best illustrated in  FIGS. 3 and 4 , the housing  12  of the latch  10  includes a cover  13  and back plate  15  between which the detent lever  50  and fork bolt  30  are sandwiched. Both the back plate  15  and the cover  13  have an opening  20  generally aligned with and complementary to the throat  32  of the fork bolt  30  when the fork bolt  30  is in an unlatched position. In one embodiment, the mouth  22  of the opening  20  is generally wider than conventional openings to prevent the striker wire  80  from contacting a portion of the opening  20 , such as a sidewall  21  for example. Additionally, the housing  12  may include a stop tab  24  formed near a corner of the housing  12 , for example between a wall  23  and the fork bolt  30 , to prevent overtravel of the fork bolt  30  as it rotates between an unlatched position and a latched position. In one embodiment, the stop tab  24  is formed by bending a portion of cover  13 , perpendicular to the plane of the cover  13  in the direction of the fork bolt  30  ( FIG. 5 ). When the fork bolt  30  is in a primary latched position, an overtravel surface  39  of the fork bolt  30 , positioned opposite the secondary shoulder  34 , is configured to contact the stop tab  24 . The overtravel surface  39  is complementary to the contour of the stop tab  24  such that when the fork bolt  30  engages the stop tab  24 , the stop tab  24  absorbs noise and vibration created by the impact from the fork bolt  30 . 
         [0024]    Referring again to  FIG. 1 , the free end of the detent lever  50  includes a resilient absorption mechanism  60 . In one embodiment, the absorption mechanism  60  is formed integrally with the detent lever  50  and is configured to engage a pin (not shown) positioned within a hole  18  between the detent lever  50  and the fork bolt  30 . Similarly, the fork bolt  30  includes a first absorption mechanism  62  adjacent the secondary shoulder  34  and a second absorption  64  mechanism adjacent the primary shoulder  40 . The first absorption mechanism  62  is configured to engage the engagement surface  54  of the detent lever  50  and the second absorption mechanism  64  is configured to engage the striker wire  80 . Each of the absorption mechanisms  60 ,  62 ,  64  of the detent lever  50  and fork bolt  30  will deform upon impact with another component, and will therefore cause a deceleration of either the detent lever  50  or fork bolt  30  respectively. Once a force is removed, the absorption mechanisms  60 ,  62 ,  64 , will return to a neutral un-deformed state. 
         [0025]    As illustrated in  FIGS. 7 and 8 , the latch  10  additionally includes a bumper  70  arranged between the housing  12  and the plane of the fork bolt  30  and detent lever  50 . The bumper  70  is positioned near the interface between the shoulder  52  of the detent lever  50  and the shoulders  34 ,  40  of the fork bolt  30 . The bumper  70  includes an upper contact portion  72  and an elongated lower portion  76  arranged generally perpendicularly to the upper contact portion  72 . In one embodiment, the bumper  70  is made from a flexible material, such as rubber or soft plastic for example. A surface  74  of the upper contact portion  72  is angled towards the bend  78  of the bumper  70 . The bumper  70  is configured to dampen sound generated by the contact between the fork bolt  30  and the striker wire  80 . 
         [0026]    When a striker wire  80  is received within the throat  32  of the fork bolt  30 , the striker wire  80  engages the second absorption mechanism  64  and applies a force thereto. Receipt of the striker wire  80  causes the fork bolt  30  to pivot from an unlatched position towards a latched position, in a direction opposite the direction indicated by arrow F, such that the contact surface  38  of the secondary shoulder  34  slidably contacts the engagement surface  54  of the detent lever  50 . As the fork bolt  30  pivots past the secondary latched position to the primary latched position, the portion  82  of the striker wire  80  within the throat  32  contacts the angled upper surface  74  of the bumper  70 . Further rotation of the fork bolt  30  to the primary latched position (fully closed position) causes portion  82  of the striker wire  80  to wedge between the angled upper surface  74  and the elongated lower portion  76  adjacent the bend  78 , as illustrated in  FIG. 8 . Once the fork bolt  30  reaches the primary latched position, the detent lever  50  is biased into contact with the primary shoulder  40  of the fork bolt  30 , thereby preventing the fork bolt  30  from rotating towards the unlatched position until the detent lever  50  is mechanically released or disengaged. In addition, the stop tab  24  formed within the housing  12  prevents further rotation of the fork bolt  30  beyond the primary latched position. As the detent lever  50  is biased into engagement with the primary shoulder  40 , the absorption mechanism  60  of the detent lever  50  contacts the adjacent pin (not shown) and deforms to slow the rotational speed of the detent lever  50 . 
         [0027]    To open the latch  10 , actuation of the release mechanism RM coupled to the detent lever  50  causes the detent lever  50  to rotate out of engagement with the fork bolt  30 . The biasing mechanism acting on the fork bolt  30  pivots the fork bolt  30  in the direction indicated by arrow F, towards the unlatched position. As the fork bolt  30  pivots open, the primary shoulder  40  applies a force to portion  82  of the striker wire  80 . The upper contact portion  72  and the elongated lower portion  76  of the bumper  70  flex to release the striker wire  80  such that the fork bolt  30  may further rotate relative to the housing  12  to an open, unlatched position. 
         [0028]    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.