Abstract:
A pawl actuation device includes a movable input member that shifts from a first position to an actuated position. The pawl actuation device also includes linkage that selectively interconnects the movable input member and the pawl such that movement of the movable input member at a first velocity causes the pawl to shift to an unlatched position, and movement of the movable input member at a second velocity that is substantially greater than the first velocity does not cause the pawl to shift to its unlatched position, such that pawl remains in its latched position.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This present application is a divisional of U.S. patent application Ser. No. 13/644,520 filed on Oct. 4, 2012, entitled “MECHANICALLY INITIATED SPEED-BASED LATCH DEVICE,” the entire contents of which are incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention generally relates to a door latch system for motor vehicles, and specifically to a door latch that does not release unless the handle is pulled open slowly. 
       BACKGROUND OF THE INVENTION 
       [0003]    Various types of vehicle door latches and handles have been developed. The latch and handle assembly may include a handle that can be pulled outwardly by a user to release a door latch, thereby permitting the door to open. However, if a vehicle is subject to a lateral acceleration, the acceleration may cause the handle to shift outwardly due to its own mass, thereby causing the latch to release. Various counterweights and inertia locks have been developed to prevent inadvertent unlatching of a door latch during lateral acceleration of the vehicle. 
         [0004]    With reference to  FIGS. 1 and 2 , a prior art latch release mechanism  5  includes an outside release lever  6  having an end  8  that is operably connected to an outside door handle (not shown) of a motor vehicle. An intermediate link  10  is pivotably connected to outside release lever  6  at a pin or pivot  12 , such that rotation of outside release lever  6  from a rest position to an actuated position causes link  10  to shift longitudinally as indicated by the arrow “A.” End  14  of link  10  includes a step or notch  16  having a push surface  18  that is configured to engage a surface  20  of a pawl lifter  22 . Pawl lifter  22  is rotatably connected to a door structure by a rotatable connector  24  which may comprise a boss, pin, shaft, or the like for movement. Link  10  is rotatably biased into engagement with pawl lifter  22  by a torsion spring (not shown) at pivot  12 . The torsion spring biases link  10  in a counter clockwise direction ( FIGS. 1 and 2 ), such that longitudinally extending surface  26  of link  10  slidably engages end surface  28  of pawl lifter  22  as link  10  moves in the direction of the arrow “A.” Thus, when assembled and in operation, surface  26  of link  10  always remains engaged with end surface  28  of pawl lifter  22 , regardless of the position and velocity of link  10 . It will be understood that, in  FIG. 1 , link  10  is shown in a rotated position solely to show surface  26 . When latch release mechanism  5  is assembled, surface  26  of link  10  always contacts/engages surface  28  of pawl lifter  22  as shown in  FIG. 2  due to rotational bias (torsion spring) acting at pivot  12 . 
         [0005]    If an exterior force tending to rotate outside release lever  6  in the direction of the arrow A 1  is applied to an outside door handle, link  10  shifts longitudinally in the direction of the arrow A with surfaces  26  and  28  slidably engaging each other initially. Surfaces  18  and  20  come into contact and abuttingly engage one another to thereby rotate pawl lifter  22  in the direction of the arrow “A 2 ” from its unlatched position to its latched position. Thus, in operation, movement of outside release lever  6  from its rest position to its actuated position always causes surface  18  of link  10  to contact surface  20  of pawl lifter  22  and always rotates pawl lifter  22  from its unlatched position to its latched position and always unlatches the vehicle door latch, regardless of the velocity at which outside release lever  6  is moved from its rest position to its actuated position. Thus, the prior art latch mechanism  5  is not capable of providing velocity-based release, and the prior art linkage is not capable of selectively interconnecting a movable input member (e.g. outside release lever  6 ) and a movable pawl member (e.g. pawl lifter  32 ) such that movement of the movable input member at a first velocity causes the movable pawl to shift to an unlatched position, and movement of the movable input member at a second velocity that is substantially greater than the first velocity does not cause the movable pawl to shift to its unlatched position, such that the movable pawl member remains in its latched position. The pawl (not shown) is directly connected to pawl lifter  22 , such that rotation of pawl lifter  22  from its unlocked position to its locked position causes the pawl to shift from the latched position to the unlatched position, thereby unlatching the vehicle door latch. 
       SUMMARY OF THE INVENTION 
       [0006]    One aspect of the present invention is a vehicle door including a device for controlling actuation of a pawl of a vehicle door latch mechanism based on a rate of movement of an exterior vehicle door handle. The vehicle door includes a door structure, and an outside door handle movably mounted to the door structure. The door also includes an outside release member that is movably mounted to the door structure. The outside release member is operably connected to the outside door handle such that movement of the outside door handle causes movement of the outside release lever from a first position to an actuated position. The vehicle door further includes a latch mechanism mounted to the door structure. The latch mechanism includes a movable latch member and a movable pawl. The movable pawl selectively retains the latch member in a latched position when the pawl is in a latched position, and permits movement of the latch when the pawl is in a unlatched position. The vehicle door still further includes an intermediate link that selectively interconnects the outside release member to the pawl lifter when the intermediate link is in an engaged configuration. The intermediate link is biased from a first disengaged configuration towards the engaged configuration. The intermediate link further defines a second disengaged position, and the intermediate link includes a first pawl-engaging surface. The movable pawl has a first link-engaging surface that engages the first pawl-engaging surface of the intermediate link when the intermediate link is in the engaged configuration to thereby cause movement of the pawl from its latched position to its unlatched position upon movement of the outside release member from its first position to its actuated position. The intermediate link includes a second pawl-engaging surface and the movable pawl has a second link-engaging surface that selectively engages a second pawl-engaging surface to retain the link in a disengaged configuration when the outside release member is in the first position. Shifting of the outside release member from the first position to the actuated position at a first velocity causes the link to shift to engaged configuration and engage the pawl and move the pawl from its latched position to its unlatched position. Shifting of the outside release member from the first position to the actuated position at a second velocity causes the link to shift from its first disengaged position to its second disengaged position without moving the pawl to its unlatched position if the second velocity is significantly greater than the first velocity. 
         [0007]    Another aspect of the present invention is a pawl actuation device including a pawl selectively locking a door latch in an engaged position when the pawl is in a latched position. The device further includes a movable input member that shifts from a first position to an actuated position. The pawl actuation device also includes linkage that selectively interconnects the movable input member and the pawl such that movement of the movable input member at a first velocity causes the pawl to shift to an latched position, and movement of the movable input member at a second velocity that is substantially greater than the first velocity does not cause the pawl to shift to its unlatched position such that pawl remains in its latched position. 
         [0008]    These and other aspects, objects, and features of the present invention will be understood and appreciated by those skilled in the art upon studying the following specification, claims, and appended drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    In the drawings: 
           [0010]      FIG. 1  is an isometric view of a prior art door latch release assembly; 
           [0011]      FIG. 2  is a schematic view of the prior art door latch release assembly of  FIG. 1 ; 
           [0012]      FIG. 3  is a partially schematic view of a latch device according to one aspect of the present invention wherein the door handle is in a closed position; 
           [0013]      FIG. 4  is a partially schematic view of a latch device according to one aspect of the present invention wherein the linkage is engaged as a result of a relatively slow outward pull of the handle; 
           [0014]      FIG. 5  is a partially schematic view of the latch device of  FIG. 4  showing the link being reset to the configuration of  FIG. 3  after release of a door handle; and 
           [0015]      FIG. 6  is a partially schematic view of the linkage device showing the link shifted to a disengaged position due to relatively rapid opening of the door handle. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0016]    For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in  FIG. 3 . However, it is to be understood that the invention may assume various alternative orientations and step sequences, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification, are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise. 
         [0017]    With reference to  FIG. 3 , a latch mechanism  30  according to one aspect of the present invention includes an outside release member such as release lever  6 A that is operably connected to an outside door handle  7  by a known linkage  9 . Movement of handle  7  causes outside release lever  6 A to rotate about pin or pivot  11 . Latch mechanism  30  also includes a link  10 A, and a pawl lifter  22 A that is operably connected to a pawl  23  of a conventional latch mechanism  25 . Outside release lever  6 A is rotatably connected to a door structure  1  by pin or pivot  11 . Link  10 A includes a step  16  defined by transverse surfaces  18  and  26 . Pawl lifter  22 A includes surfaces  20  and  28  that engage surfaces  18  and  26 , respectively, of link  10 A. Pawl lifter  22 A includes a prong or extension  32  having an end surface  34 . (See also  FIG. 4 ). Link  10 A includes a block or extension  38  defining a surface  36  that engages end surface  34  of prong  32  of pawl lifter  22 A when the mechanism  30  is in the configuration of  FIG. 3 .  FIG. 3  shows a configuration in which the door is closed and latched, and the outside door handle is in a non-actuated or rest position. 
         [0018]    If the outside door handle  7  is pulled open slowly in the direction of arrow B 3  towards the position  7 A, link  10 A shifts in the direction of the arrow B ( FIG. 4 ), and surface  36  of link  10 A slides along surface  34  of prong  32  of pawl lifter  22 A until the surfaces  36  and  34  disengage from one another, resulting in counterclockwise rotation of link  10 A. Once the surfaces  34  and  36  disengage, the counterclockwise bias acting on link  10 A initially causes link  10 A to rotate, bringing surfaces  26  and  28  of link  10 A and pawl lifter  22 A, respectively, into contact with one another. As handle  7  and outside release lever  6 A are further rotated, link  10 A shifts longitudinally in the direction of the arrow B. Surfaces  18  and  20  of link  10 A and pawl lifter  22 A, respectively, then come into contact/engagement with each other. Further rotation of handle  7  and outside release lever  6 A further shifts the link  10 A in the direction of the arrow B, thereby rotating pawl lifter  22 A in the direction of the arrow B 2 . Rotation of pawl lifter  22 A releases the pawl  23  of the latch mechanism  25 , thereby unlatching the latch mechanism  25  and permitting the vehicle door to open. 
         [0019]    With further reference to  FIG. 5 , a spring of a known type (not shown) biases lever  6 A and handle  7  in directions opposite arrows B 1  and B 3 , respectively. Thus, after a user releases the handle  7  the handle  7  rotates in a direction that is opposite arrow B 3 , and lever  6 A rotates in the direction opposite the arrow B 1 . Rotation of lever  6 A causes link  10 A to shift in a direction opposite the arrow B. As the link  10 A shifts in a direction opposite the arrow B, a corner surface  40  of block  38  of link  10 A slides along surface  42  of prong  32  of pawl lifter  22 A, and surfaces  26  and  28  of link  10 A and pawl lifter  22 A, respectively, disengage from one another. As the link  10 A continues to shift in a direction opposite the arrow “B”, the link  10 A and pawl lifter  22 A rotate in a clockwise direction, and return to the configuration shown in  FIG. 3 , thereby resetting the latch mechanism  30  to its initial or rest position. 
         [0020]    In the event the latch mechanism  30  is in the rest or initial position of  FIG. 3 , and if outside release lever  6 A is rotated in the direction of the arrow B 1  at a relatively high velocity, the link  10 A will shift in the direction of the arrow B as shown in  FIG. 6 , and surface  44  of link  10 A will slidably engage end surface  28  of pawl lifter  22 A as shown in  FIG. 6 . High velocity rotation of release lever  6 A causes outside corner  46  of link  10 A to slide past outside corner  48  of pawl lifter  22 A, resulting in sliding engagement between surface  44  of link  10 A and end surface  28  of pawl lifter  22 A. However, this sliding engagement does not generate sufficient force to rotate pawl lifter  22 A in the direction of the arrow B 2 . As discussed above, link  10 A is rotatably biased in a counterclockwise direction ( FIG. 6 ). However, if the link  10 A is shifted in the direction of the arrow B quickly enough, the link  10 A will not rotate to the engaged position of  FIG. 4 , but rather will shift to the disengaged configuration of  FIG. 6 . Because push surface  18  of link  10 A does not engage surface  20  of pawl lifter  22 A when the latch mechanism  30  is in a configuration of  FIG. 6 , further rotation of outside release lever  6 A due to outward movement of the vehicle door handle will not result in rotation of pawl lifter  22 A. Pawl lifter  22 A may be rotationally biased in a direction opposite arrow B 2  to prevent movement of pawl lifter  22 A due to sliding contact between surfaces  26  and  28  of link  10 A and pawl lifter  22 A, respectively. 
         [0021]    It has been found that a user will typically move a door handle (e.g. handle  7 ) at 300 mm/s or less when opening a vehicle door. However, the handle  7  will typically move at 2500 mm/s or more in the event a vehicle is subject to a side impact event. Accordingly, in the illustrated example, the latch mechanism  30  is configured such that movement of the handle at 300 mm/s or less will result in the link  10 A shifting to the engaged position of  FIG. 4 , thereby resulting in rotation of pawl lifter  22 A and movement of the pawl to an unlatched position. However, if the outside handle is moved at 2500 mm/s or more, the outside corner  46  of link  10 A slides past outside corner  48  pawl lifter  22 A as shown in  FIG. 6 , such that pawl lifter  22 A does not rotate, and the pawl of the door latch is not shifted to an unlatched position. 
         [0022]    It is to be understood that variations and modifications can be made on the aforementioned structure without departing from the concepts of the present invention, and further it is to be understood that such concepts are intended to be covered by the following claims unless these claims by their language expressly state otherwise.