Abstract:
A latch assembly for a vehicle is provided that includes a latch, a pawl coated with a semi-rigid overmold material, wherein the pawl is configured to hold the latch closed and is actuated to release the latch, and a pawl isolation member operably coupled to an outer surface of the pawl, wherein the pawl isolation disk absorbs energy during operation of the latching assembly.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention generally relates to a vehicle door latch mechanism, and more particularly relates to a pawl isolation member for latch closing sound quality. 
       BACKGROUND OF THE PRESENT INVENTION 
       [0002]    Often, consumers equate the performance and quality of vehicles and vehicle components with sound quality and minimal noise, vibration, and harshness (NVH) characteristics of vehicle components including the latching mechanism of a vehicle door. Providing a vehicle door that opens and closes properly and performs each of those functions with minimal audible indication can suggest to a consumer that the overall door assembly, the door closing mechanism, and the vehicle are of high quality. 
       SUMMARY OF THE PRESENT INVENTION 
       [0003]    Accordingly, in a first disclosed embodiment, a latch assembly for a vehicle is provided that includes a latch, a pawl coated with a semi-rigid overmold material, wherein the pawl is configured to hold the latch closed and is actuated to release the latch, and a pawl isolation member in abutment with an outer surface of the pawl, wherein the pawl isolation disk absorbs energy during operation of the latching assembly. 
         [0004]    In another disclosed embodiment, an energy absorption assembly for a vehicle is provided that includes a pawl at least partially coated in a semi-rigid material, and a pawl isolation member including an aperture disposed therethrough, wherein the pawl isolation member is in abutment with a surface of the pawl, and wherein the pawl isolation member absorbs energy during operation of the pawl. 
         [0005]    In another disclosed embodiment, a method for making an assembly for absorbing energy during vehicle door actuation is provided that includes the steps of providing a latch, providing a pawl coated with a semi-rigid overmold material, arranging the pawl to hold the latch closed and actuating the pawl to release the latch, thereby facilitating opening and closing of the vehicle door, and placing a pawl isolation member into abutment with an outer surface of the pawl. 
         [0006]    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 
         [0007]      FIG. 1  is a top perspective view of a vehicle with a vehicle door incorporating one embodiment of the present invention; 
           [0008]      FIG. 2  is a top perspective exploded view of a vehicle door latch mechanism of the present invention; 
           [0009]      FIG. 3  is a top perspective view of one embodiment of a striker bumper of the present invention; 
           [0010]      FIG. 4  is a first side elevational view of the striker bumper of  FIG. 3 ; 
           [0011]      FIG. 5  is a second side elevational view of the striker bumper of  FIG. 3 ; 
           [0012]      FIG. 6  is a front elevational view of the striker bumper of  FIG. 3 ; 
           [0013]      FIG. 7  is a rear elevational view of the striker bumper of  FIG. 3 ; 
           [0014]      FIG. 8  is a top plan view of the striker bumper of  FIG. 3 ; 
           [0015]      FIG. 9  is a bottom plan view of the striker bumper of  FIG. 3 ; 
           [0016]      FIG. 10  is a top perspective exploded view of a catch, a pawl, and a pawl isolation disk of the vehicle door latch mechanism; 
           [0017]      FIG. 11  is a top perspective view of the pawl isolation disk; 
           [0018]      FIG. 12  is a side elevational view of the pawl isolation disk; 
           [0019]      FIG. 13  is an enlarged top perspective view of the vehicle door of  FIG. 1  illustrating the vehicle door latch mechanism in an open position; 
           [0020]      FIG. 14  is a top perspective view of the vehicle door latch mechanism in the open position; 
           [0021]      FIG. 15  is a side elevational view of the vehicle door latch mechanism in the open position; 
           [0022]      FIG. 16  is a side elevational view of the vehicle door latch mechanism in the open position with the frame plate removed; 
           [0023]      FIG. 17  is a side elevational view of the vehicle door latch mechanism in a semi-closed position; 
           [0024]      FIG. 18  is a side elevational view of the vehicle door latch mechanism in a semi-closed position with the frame plate removed; 
           [0025]      FIG. 19  is an enlarged top perspective view of the vehicle door latch mechanism in the closed position; 
           [0026]      FIG. 20  is a top perspective view of the vehicle door latch mechanism in the closed position; 
           [0027]      FIG. 21  is a side elevational view of the vehicle door latch mechanism in a closed position; and 
           [0028]      FIG. 22  is a side elevational view of the vehicle door latch mechanism in a closed position with the front plate removed. 
       
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS 
       [0029]    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. 1 . However, it is to be understood that the invention may assume various alternative orientations, 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. 
         [0030]    Referring now to the embodiment illustrated in  FIGS. 1 and 2 , the reference numeral  10  generally designates a vehicle door latch mechanism having a frame plate  12 . A catch  14  is rotatably connected with the frame plate  12  and includes a striker retaining slot  16 . A pawl  18  is operably connected with the frame plate  12 . A pawl isolation disk  20  is disposed between the pawl  18  and the frame plate  12 . A striker  22  ( FIG. 17 ) is adapted for engagement with the catch  14 . A striker bumper  24  is adjacent the frame plate  12  and includes an abutment surface  26  and a striker damper surface  28 . 
         [0031]    Referring again to  FIGS. 1 and 2 , the vehicle door latch mechanism  10  is generally designed for use on a vehicle  30 , having a vehicle door  32  with a door handle  31  and that is rotatable about a door hinge mechanism  33 . The vehicle door latch mechanism  10  may be installed on the driver side door, passenger side door, or rear passenger doors. Additionally, the vehicle door latch mechanism  10  may be installed in the vehicle door opening on the B-pillar or may be disposed on an engagement side of the door, as represented in  FIG. 1 . The vehicle door latch mechanism  10  includes a housing  34  behind the frame plate  12  that helps protect the vehicle door latch mechanism  10  from damage, as well as dirt and debris. The housing  34  is secured to the vehicle door  32  by a plurality of mechanical fasteners. The catch  14  is disposed behind the housing  34  between the frame plate  12  and the housing  34  and is rotatably coupled with the housing  34 . The housing  34  and frame plate  12  generally form the striker retaining slot  16  adapted to receive the striker  22 . The striker  22  is designed to engage the catch  14 , as will be disclosed in further detail below. 
         [0032]    Referring now to the embodiment illustrated in  FIGS. 3-9 , the striker bumper  24  includes a body portion with a striker damper surface  28  and an abutment surface  26  that is substantially orthogonal to the striker damper surface  28 . A damper tab  36  is positioned above the abutment surface  26 . The damper tab  36  includes a triangular construction with a peak  37  of the triangular construction disposed at a topmost portion of the striker bumper  24 . The peak  37  is adapted to abut a catch bumper  39  ( FIG. 16 ) of the catch  14  of the vehicle door latch mechanism  10  during opening to prevent the catch  14  from making an impact sound when a door handle  31  is opened. A base portion  38  of the striker bumper  24  includes a plurality of scalloped recesses  40  upon which the striker bumper  24  rests when in position in the vehicle door latch mechanism  10 . 
         [0033]    A securing slot  42  is disposed in the body portion of the striker bumper  24 . The securing slot  42  receives a damper plate  44  ( FIG. 16 ) that abuts the striker  22  during opening and closing of the vehicle door  32  as disclosed in further detail below. Adjacent to the damper tab  36  is a planar engagement area  46  that helps secure the striker bumper  24  in position in the vehicle door latch mechanism  10 . The planar engagement area  46  is orthogonal to the abutment surface  26  and substantially coplanar with the striker damper surface  28  of the striker bumper  24 . An engagement wall  47  is disposed substantially orthogonal to the abutment surface  28  and is designed to rest against the housing  34  of the vehicle door latch mechanism  10 . 
         [0034]    The striker bumper  24  is generally constructed of polynorbornene, which acts as a damper that does not respond to compression by storing a substantial amount of elastic energy. Accordingly, the striker bumper  24  receives applied forces developed during the closure of the vehicle door  32  and absorbs those forces without storing substantial potential energy. Consequently, little or no stored elastic energy is disposed in the striker bumper  24  when the vehicle door  32  is in the closed position, as will be discussed in more detail below. 
         [0035]    Referring to  FIGS. 10-12 , the pawl  18  may be coated with a semi-rigid overmold material, which assists in sound dampening during operation of the vehicle door latch mechanism  10 . The overmold coating material is semi-rigid. The pawl isolation disk  20  mounted between the pawl  18  and the frame plate  12  assists in dampening sound generated during operation of the vehicle door latch mechanism  10 . Specifically, sound created due to engagement/disengagement of the pawl  18  and catch  14 , movement of the pawl  18 , and vibrations associated with the pawl  18  and the adjacent frame plate  12  are dampened by the pawl isolation disk  20 . The pawl isolation disk  20  may optionally be operably coupled to an outer surface of the pawl  18  or frame plate  12  and reside between the pawl  18  and the housing  34 , as mentioned above or can be sandwiched between the pawl  18  and the frame plate  12  without being coupled to either. Alternatively, the pawl isolation disk  20  may be integrally formed with the pawl  18  as a single manufactured component. 
         [0036]    The pawl isolation disk  20  may be formed of any suitable sound-dampening material, including Santoprene. The hardness of the pawl isolation disk  20  is approximately 80 Shore A durometer, but may be lowered as the disk thickness is increased. The pawl isolation disk  20  may be formed of various geometric configurations, but typically will be shaped as a circular disk, as illustrated in  FIGS. 11 and 12 . Irrespective of the specific geometric configuration, the pawl isolation disk  20  includes an aperture and is mounted to the pawl  18 , such that the pawl isolation disk  20  circumferentially surrounds a pawl aperture  48 , which defines an axis about which the pawl  18  rotates. The pawl isolation disk  20  may be mounted to the pawl  18  by a suitable adhesive or mechanical fastener or can be molded onto the pawl  18  by a two shot molding process. The pawl isolation disk  20  thickness will range based on the application, however, a thickness of approximately 1/32″ may be employed successfully. This thickness may increase or decrease and this variability will adjust the appropriate hardness of the pawl isolation disk  20 . 
         [0037]    Although the pawl isolation disk  20  may absorb energy during all phases of the opening and closing process of the vehicle door latch mechanism  10 , the most critical energy absorption that leads to sound dampening occurs at a final stage of closure and at the initial stage of opening of the vehicle door latch mechanism  10 . Specifically, during a closing process of the vehicle door  32 , the critical sound dampening occurs upon engagement of the pawl  18  and the catch  14 . During an opening process of the vehicle door  32 , the critical sound dampening occurs upon disengagement of the pawl  18  and catch  14 . 
         [0038]    Referring to  FIGS. 13-22 , the vehicle door latch mechanism  10  is operable between a closed, semi-closed, and an open position. The catch  14  includes a first stop  50  and a second stop  52  that correspond with the closed and semi-closed positions, respectively. The vehicle door  32  is in the open position ( FIGS. 13-16 ) when the engagement side of the vehicle door  32  is not proximate the B-pillar of the vehicle door  32  opening and passengers can enter or exit the vehicle door  32  opening. The vehicle door  32  is in the semi-closed position ( FIGS. 17 and 18 ) when the vehicle door  32  is not completely closed and sealed against the door opening. Stated differently, the semi-closed position is when the vehicle door  32  is latched but slightly ajar. The vehicle door  32  is in the closed position ( FIGS. 19-22 ) when the vehicle door  32  is fully latched and sealed against the vehicle door  32  opening, which includes full engagement between the pawl  18  and the catch  14 . 
         [0039]    Referring again to  FIGS. 13-22 , the striker retaining slot  16  of the catch  14  opens outwardly when the catch  14  is in the open position such that a receiving slot  54  in the frame plate  12  is aligned with the striker retaining slot  16 . The catch  14  rotates about a pivot pin (not shown) between a fully-rotated position, semi-rotated position, and open position that corresponds with the closed, semi-closed, and open positions of the door, respectively. As will be understood by one having ordinary skill in the art, the pawl  18  is released by actuation of the vehicle door handle  31  by a user. When the pawl  18  is released, the catch  14 , which is spring-biased to the open position, is free to rotate to the open position, thus releasing the striker  22  so that the vehicle door  32  can be opened. In the illustrated embodiment, the catch  14  is spring-biased to the open position by a clock spring (not shown) disposed behind the catch  14 . 
         [0040]    When the vehicle door  32  is in the open position ( FIGS. 13-16 ), the catch  14  is in the open position such that the striker retaining slot  16  is available to receive and retain the striker  22 . As mentioned above, when the striker retaining slot  16  is in the open position, the striker retaining slot  16  is generally adjacent to and parallel with the receiving slot  54 . During closure, the vehicle door latch mechanism  10  swings with the vehicle door  32  about the door hinge mechanism  33  ( FIG. 1 ) and engages the striker  22 . More specifically, the receiving slot  54  receives the striker  22 . As the striker  22  engages the receiving slot  54 , the striker  22  also engages the striker retaining slot  16 . At the same time, the striker  22  also makes tangential contact with the damper plate  44  juxtapositioned over the striker damper surface  28 . The damper plate  44  serves to protect the striker damper surface  28  from excessive wear during extended use of the vehicle door latch mechanism  10 . The damper plate  44  may be in abutting contact with the striker damper surface  28 , or disposed slightly above the striker damper surface  28 . In either instance, at least a portion of the damper plate  44  is received in the securing slot  42  of the striker bumper  24 . The striker  22  is guided over the damper plate  44  into the striker retaining slot  16 . 
         [0041]    As the striker  22  engages the striker retaining slot  16 , the catch  14  rotates downward under the force of the closing vehicle door  32  to secure the striker  22  in one of the fully-rotated or semi-rotated positions. When a predetermined minimum amount of closure force is not met, the vehicle door  32  either does not close or only latches, thus placing the vehicle door  32  in the semi-closed position. When the vehicle door latch mechanism  10  is in the semi-closed position, the catch  14  receives the striker  22  into the striker retaining slot  16 , but does not rotate to the fully-rotated position. 
         [0042]    When the predetermined minimum amount of force is applied to the vehicle door  32  during the act of closure, the catch  14  of the vehicle door latch mechanism  10  engages the striker  22 . Upon contact with the striker  22 , the catch  14  rotates past the semi-rotated position to the fully closed position. When the vehicle door latch mechanism  10  is in the fully closed position, the striker  22  engages the abutment surface  26  of the striker bumper  24 . As the striker  22  engages the abutment surface  26 , excess energy used in closing the vehicle door  32  is received and absorbed into the abutment surface  26  of the striker bumper  24  and dissipated. As a result, the NVH characteristics of the vehicle door  32  closing event are minimized. The vehicle door  32  is now in the fully closed position. 
         [0043]    Referring again to  FIGS. 13-16 , to return the vehicle door  32  to the open position, a user actuates the handle  31  connected with the vehicle door latch mechanism  10 , actuating the same. As the door handle  31  is actuated, the catch  14  rotates clockwise a small amount, thereby allowing the pawl  18  to rotate counterclockwise out of interference with the first stop  50  of the catch  14 . During actuation of the door handle  31  and rotation of the catch  14  clockwise, the catch bumper  39  abuts the damper tab  36  ( FIG. 16 ), thereby minimizing the noise output associated with actuation of the door handle  31  during the vehicle door  32  opening sequence. When the pawl  18  has rotated a predetermined distance counterclockwise, the catch  14  rotates counterclockwise and the pawl  18  clears the first stop  50  and the second stop  52  that correspond with the closed and semi-closed positions, respectively. The vehicle door  32  is then pulled open by a user, which results in the striker  22  being withdrawn from the striker retaining slot  16  and ultimately the receiving slot  54 . As the striker  22  is withdrawn from the receiving slot  54  and the striker retaining slot  16 , the catch  14  continues to rotate under spring-bias in a counterclockwise direction until the striker retaining slot  16  is once again aligned with the receiving slot  54  and ready for subsequent engagement of the striker  22  during another closure event. 
         [0044]    Each of the pawl isolation disk  20  and the striker bumper  24  decrease the noise output levels associated with operation of the vehicle door latch mechanism  10 . Specifically, as the striker  22  enters or exits the vehicle door latch mechanism  10 , significant energy is transferred in the overall system and released in part as noise. The pawl isolation disk  20  and the striker bumper  24  independently reduce this noise output substantially. Typically, this noise level will be within 92-98 decibels in response to typical forces associated with a closing action, but testing has produced even lower decibel levels. The pawl isolation disk  20  and striker bumper  24  are formed of a material and geometry, such that their absorption of energy during opening or closing of the vehicle door  32  reduces the decibel level heard by an occupant of the vehicle  30 . 
         [0045]    To minimize NVH characteristics of the vehicle door  32  closing and opening sequences, dampers are installed into the vehicle door latch mechanism  10  to lower the decibel output associated with these events. The pawl isolation disk  20  and striker bumper  24  lessen noise output during the vehicle door  32  unlatching, opening, and closing events. 
         [0046]    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.