Abstract:
The instant disclosure provides a push latch having a pivotally mounted blocking hammer including a head with a lever arm extending away from the head to a counter-weight. Under normal operating conditions, the hammer is held in an inert/balanced condition. Under such normal conditions, a portion of the hammer head may be in periodic contact with a resin of tacky character defining a bumper to aid in dampening vibration. Upon the occurrence of a high impact force, the rotational force provided by the counterweight is sufficient to cause the hammer to rotate into blocking relation relative to the latching mechanism so as to prevent unlatching. In the rotated condition, the counterweight may be in contact with an optional resin of tacky character defining a bumper to reduce rebound action.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of, and priority from, U.S. Provisional Application 61/521,516 filed Aug. 9, 2011. The contents of such Provisional Application are hereby incorporated by reference in their entirety as if fully set forth herein. 
     
    
     TECHNICAL FIELD 
       [0002]    The present disclosure relates generally to latches, and more specifically to push/push latches. By way of example only, such latches may find application in locking bins and other storage containers in various environments of use including automotive vehicles, aircraft and the like. 
       BACKGROUND 
       [0003]    It is known that push/push latches (i.e., push to open/push to close latches) are used in various applications to perform various functions. One environment of use for push/push latches is in the production of various transportation vehicles. In the transportation industry, push/push latches are used in many applications such as overhead or dashboard compartments. By way of example only, to open an overhead compartment such as a sunglasses bin or the like, a user may push on the compartment door which will release the latch holding the compartment causing the compartment to open. A similar pushing action on the compartment door will cause the compartment to close and the latch to engage the compartment, thereby holding the compartment in the closed position. 
         [0004]    Many different configurations of push/push latches are known. In one exemplary construction, a push/push latch device may include a reciprocating track, a housing surrounding the track, and a follower with a pin that moves in the track to actuate the push/push latch. Some known push/push latches may have a tendency to unlatch when a significantly large force is exerted on them, such as during a vehicle collision event. In an effort to address this problem, some prior devices have used a blocking plate to prevent the pin from moving in the track during unwanted forces. A potential drawback with this design is that when subjected to extreme forces, the blocking plate has the potential to sever or deform the pin thereby preventing subsequent, future use of the latch. Another known drawback with this design is that during a low force situation, such as a low impact vehicle collision, the plate may not move in a sufficiently rapid manner to block the pin to prevent the unlatching or opening of the latch. 
         [0005]    A design which is believed to substantially overcome the problem of unlatching when subjected to large forces is disclosed in U.S. Pat. No. 7,793,995 to King et al. the contents of which are incorporated by reference herein in their entirety. While this design is highly functional, the present design is believed to represent a further useful and beneficial refinement to such art. 
       SUMMARY OF THE DISCLOSURE 
       [0006]    The present disclosure is directed to a latch, specifically a push latch which may be used in various applications, including in transportation vehicles. The push latch of the present disclosure may be used in high and low g-force situations, such as those generated in high and low impact vehicle collisions. In particular, the disclosure provides a push latch having a pivotally mounted blocking hammer including a head with a lever arm extending away from the head to a counter-weight. Under normal operating conditions, the hammer is held in an inert/balanced condition. Under such normal conditions, a portion of the hammer head may be in periodic contact with a resin of tacky character defining a bumper to aid in dampening vibration. Upon the occurrence of a high impact force, the rotational force provided by the counterweight is sufficient to cause the hammer to rotate into blocking relation relative to the latching mechanism so as to prevent unlatching. In the rotated condition, the counterweight may be in contact with an optional resin of tacky character defining a bumper to reduce rebound action. The optional resin may be cured to a desired level of tackiness by UV exposure or other suitable techniques. In normal operation, the optional resin may reduce noise from the hammer hitting and rebounding relative to opposing surfaces. When the hammer is rotated into blocking relation relative to the latching mechanism, the optional resin assists in holding the hammer in the rotated blocking position continuously throughout the entire force event which may include multiple impacts in different directions such as during a roll-over event or the like. 
         [0007]    By way of example only, and not limitation, in accordance with one exemplary aspect, the present disclosure provides a push latch mechanism including a housing having a slot with a latch body having a track disposed across a surface positioned within the housing. The latch body is movable relative to the housing such that the relative movement of the latch body defines a latch body travel path. A follower may be positioned in the slot with the follower being operatively connected to a pin extending outward from the follower and in engagement with the track, such that the pin moves along the track while the follower moves along the slot. A hammer may be pivotally mounted about an axis of rotation below the latch body. The hammer may include a curved hammer head extending away from a lever arm and towards the latch body such that the lever arm and hammer head form a dogleg profile. A counter-weight may extend away from the lever arm and away from the latch body at a position remote from the hammer head. A biasing spring may be positioned between the counter-weight and the axis of rotation such that the biasing spring urges the lever arm and counter-weight towards the latch body. The hammer is movable between a first position and a second position, such that in the first position the head does not obstruct the travel path of the latch body, and such that in the second position the hammer head does obstruct the travel path of the latch body, thereby preventing the latch mechanism from opening. When moving from the first position to the second position due to a g-force condition, the counterweight moves in a first direction, and when the g-force condition has sufficiently dissipated, the hammer moves back to the first position in a direction that is opposite the first direction. A hammer head bumper of tacky, pliable resin may be disposed along a wall of the housing in opposing relation to an outboard surface of the hammer head such that rotation of the hammer head brings the outboard surface into contact with the hammer head bumper. This hammer head bumper aids in reducing noise from the hammer hitting and rebounding relative to opposing surfaces. A counter-weight bumper of tacky, pliable resin may be disposed at a wall positioned along a travel arc for the counter-weight in opposing relation to an inboard surface of the counter-weight such that rotation of the hammer head brings the inboard surface of the counter-weight into contact with the counter-weight bumper. The counter-weight bumper assists in suspending the hammer temporarily from moving back to the first position for a period of time after the g-force is dissipated. 
         [0008]    Other exemplary features and advantages of the disclosure will become apparent to those of skill in the art upon review of the following detailed description, claims and drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a schematic perspective view illustrating an exemplary push/push latch consistent with the present disclosure; 
           [0010]      FIG. 2  is an exploded view illustrating the components of the exemplary push/push latch of  FIG. 1  in separated condition; 
           [0011]      FIG. 3  is a schematic perspective view illustrating the interior of the exemplary push/push latch of  FIG. 1 ; 
           [0012]      FIGS. 4-6  are schematic cut-away views illustrating normal operation of the exemplary push/push latch of  FIG. 1 ; 
           [0013]      FIGS. 7-8  are schematic cut-away views illustrating operation of the exemplary push/push latch of  FIG. 1  when subjected to a high g-force event while in a latched condition; 
           [0014]      FIG. 9  is schematic cut-away view illustrating the optional placement of a tacky resin within the exemplary push/push latch of  FIG. 1 ; and 
           [0015]      FIG. 10  is schematic cut-away view illustrating the engagement between the hammer of the exemplary push/push latch and the tacky resin. 
       
    
    
       [0016]    Before exemplary embodiments are explained in detail, it is to be understood that the disclosure is in no way limited in its application or construction to the details and the arrangements of the components set forth in the following description or illustrated in the drawings. Rather, a load transfer apparatus in accordance with the present disclosure is capable of other embodiments and of being practiced or carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein are for purposes of description only and should not be regarded as limiting. The use herein of terms such as “including” and “comprising” and variations thereof is meant to encompass the items listed thereafter and equivalents thereof as well as additional items and equivalents thereof. 
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0017]    Reference will now be made to the drawings, wherein to the extent possible, like elements are designated by like reference numerals throughout the various views. Referring now to  FIGS. 1-3 , in one exemplary embodiment, the present disclosure is directed to a push/push latch  10  which may include a latch body  12 , a housing  14  encompassing the latch body  12 , a hammer  16 , a follower  18 , and a pin  20 . The housing  14  may have numerous configurations depending on the application and may include opposing, flexible angled tab members  22  that are used to snap-fit or otherwise secure the housing and thus the latch  10  to a substrate, such as a panel of a vehicle or other mounting structures. By way of example only, and not limitation, the housing may be formed as a unitary structure from high impact plastic, acetal resin, or other suitable materials by techniques such as injection molding or the like as will be well known to those of skill in the art. Of course, other materials such as metal and the like also may be used if desired. 
         [0018]    The housing  14  is configured to receive the latch body  12  and to permit slidable movement of the latch body  12  relative to the housing. The slidable movement of the latch body  12  within the housing  14  defines a path of travel. In this regard, during normal operation of the latch in the absence of an impact or other event producing high g-forces, the latch  10  will operate in a manner corresponding to the normal operation of the latch described in U.S. Pat. No. 7,793,995 which is hereby incorporated by reference in its entirety as if fully set forth herein. 
         [0019]    As best seen through joint reference to  FIGS. 2 and 3 , the latch body  12  may include a track  24  on one side of the latch body  12 . In the exemplary embodiment, the track  24  is formed by grooves and angled surfaces that define a path to allow the pin  20  to travel in camming relation along the angled surfaces within the grooves. In this regard, the pin  20  will follow the track  24  during the push/push operation of the latch  10 , i.e., during the opening and closing of the latch, and the position of the pin  20  relative to the track  24  determines whether the latch is open or closed. As will be appreciated, the track  24  may be molded into the surface of the latch body  12  during the formation process and may have any number of configurations depending on the latching characteristics desired. 
         [0020]    In the illustrated exemplary construction, the pin  20  is operatively connected to the follower  18 . The follower  18  moves within an opening or slot  28  extending along the housing  14  and along opposing rails  30  positioned on opposite sides of the opening or slot  28 . As will be appreciated, the follower  18  moves as the pin  20  moves along the track  24 . That is, as the latch body  12  moves vertically within the housing  14  the pin  20  is held at a stationary elevation and moves along the track  24 . As the pin moves along the track, the follower  18  slides back and forth along the rails  30 . This slidable movement permits the latch body  12  to move relative to the housing  14 , thereby causing the pin to assume various positions within the track corresponding to open and closed conditions. 
         [0021]    Referring now jointly to  FIGS. 3-6 , in the illustrated exemplary construction, when the pin  20  is at the bottom of the track  24 , near distal end of the latch body  12 , the latch  10  will be in an open position and the latch body  12  will extend out from an axial opening  32  in proximal end  34  of the housing  14  ( FIG. 4 ). As the latch body  20  is depressed, the pin  20  and follower  18  move along an outer dogleg wall  36  until achieving a position corresponding to maximum push-in shown in  FIG. 5 . As will be well understood by those of skill in the art, the maximum push-in state is transitory only and is not maintained after the compressing force on the latch body  12  is released. In this regard, as the compressing force is released, the latch body  12  is urged upwardly by an internal latch spring  40  ( FIG. 2 ) and the pin  20  is captured within a notch  42  on a raised island  44  at the interior of the track  24  to assume the locked position shown in  FIG. 6 . Since the pin  20  does not move vertically, outward movement of the latch body  12  is blocked and a latched condition is maintained. However, from the latched condition shown in  FIG. 6 , a user may reapply the compressing force so as to disengage the pin from the notch  42 . Release of the compressing force then causes the pin  20  to resume the starting position at the bottom of the track. Of course, this sequence may be repeated numerous times over the course of use. 
         [0022]    It is to be understood that the illustrated track configuration is merely exemplary and virtually any other track configuration as maybe known to those of skill in the art also may be used. Likewise, other configurations of the latch body, latch housing, pin and follower are possible. Accordingly, many possible latch configurations may be used in accordance with the present disclosure. 
         [0023]    Referring to  FIGS. 1 and 2 , in accordance with the present disclosure, the latch  10  may include an end cap  46  of molded plastic, acetal resin, or the like adapted for connection in at least partial covering relation to the distal end of the housing  14 . By way of example only and not limitation, in the illustrated exemplary construction the end cap  46  may include a pair of integral, molded-in spring tabs  48  (only one shown) projecting outwardly and downwardly from opposing sidewalls. During assembly, the end cap  46  may be inserted between a pair of downwardly extending ears  50  at the distal end of the housing  14  such that the spring tabs  48  may flex inwardly and then spring outwardly through aligned window openings  52  thereby holding the end cap in place. 
         [0024]    Prior to attachment of the end cap  46  to the housing  14 , the hammer  16  may be rotatably mounted within the end cap  46  by a pin  54  seated in molded-in depressions within opposing raised walls of the end cap  46 . In the mounted condition, the hammer  16  is held in raised relation away from the floor surface of the end cap  46  such that the hammer  16  may rotate at least partially about an axis of rotation defined by the pin  54 . As best seen in  FIGS. 9 and 10 , the floor of the end cap  46  may include a raised step  56  extending partially across the end cap  46  and disposed below the pin connection when the end cap  46  is in the assembled condition. As will be described further hereinafter, this raised step acts to limit rotation of the hammer  16  during operation. 
         [0025]    In accordance with the illustrated exemplary embodiment, the hammer  16  may have a generally dogleg configuration having a curved hammer head  60  extending in upwardly angled relation away from a lever arm  62  such that the axis of rotation defined by the pin  54  is slightly above the intersection between the hammer head  60  and the lever arm  62 . However, other pin positions also may be used. In the illustrated embodiment, the hammer  16  also includes a counter-weight  64  positioned opposite the hammer head  60  such that the lever arm  62  extends operatively between counter-weight  64  and hammer head  60 . A relatively light weight spring  65  may be disposed in upward biasing relation to the lever arm  62  at a position between the pin  54  and the counter-weight  64 . As further explained below, in the event of a g-force condition exceeding the range of normal operating conditions, the counter-weight  64  will pivot about the pin  54 , thereby overcoming the biasing force of spring  65  and causing the hammer head  60  to move into the path of travel of the latch body  12 . In this blocking position, further movement of the latch body  12  is prevented, and the latch body  12  is thereby precluded from moving to an open or unlatched position. 
         [0026]    Referring now to  FIGS. 7 and 8 , in the illustrated exemplary construction the outboard side  66  of the outer dogleg wall  36  may include an outwardly projecting nose  68  extending generally towards the hammer  16 . As best seen in  FIGS. 8 and 10 , the lower edge of the outwardly projecting nose  68  may form a shoulder  70  positioned to engage the distal end of the hammer head  60  when the hammer  16  rotates during a g-force condition. That is, when the latch  10  is subject to a g-force condition, such as during a collision event, the hammer counter-weight  64  will rotate about the connecting pin  54  until the hammer head  60  moves into the path of travel of the latch body  12 . This rotation takes place until the counter-weight  64  contacts the opposing surface of the raised step  56 . As the g-force condition causes the latch body  12  to move within the housing  14 , the shoulder  70  will contact the hammer head  60  which will stop further movement of the latch body  12 . Thus, the latch body  12  is held in the latched position as illustrated in  FIG. 8 . During this blocked condition, downwardly applied force on the latch body  12  will continue to urge the hammer  16  to the blocking position shown in  FIG. 8 . However, when the g-force condition has dissipated or when no g-force is exerted on the latch  10 , the hammer spring  65  in combination with the mass of the hammer head  60  overcomes the counter-weight and the hammer head  60  rotates back to its neutral position ( FIG. 7 ). In this neutral position, the latch  10  will thereafter be fully operational. Thus, the latch  10  may be reused following the collision event. 
         [0027]    As best seen in  FIGS. 2 ,  7  and  8 , the hammer head  60  may have a generally claw-shaped profile having a rounded distal tip  72  which projects rearwardly at an angle towards a wall of the housing corresponding to a plane disposed in opposing adjacent relation to the outboard surface of the counter-weight  64 . As shown, a substantially planar upper surface  74  may extend in radially inwardly angled relation to a substantially planar hammer head outboard surface  76 . In the illustrated, exemplary construction, the hammer head outboard surface  76  may form a substantially right angle with the lever arm  62 , although other angled relationships may be used. Of course, it is to be understood that while a potentially preferred embodiment for a hammer has been illustrated and described, any number of other hammer configurations may likewise be used. Accordingly, as used herein, the term “hammer” refers to any device that, in the event of a g-force condition, may move into or otherwise obstruct the path of movement of the latch body  12  or otherwise prevent the opening of the latch. 
         [0028]    Referring now to  FIGS. 9 and 10 , in accordance with one exemplary practice, a resin or other curable fluid of slightly tacky surface character in the cured condition may be positioned in opposing relation to the hammer head outboard surface  76  and/or across the outboard surface of the raised step  56  in opposing relation to the inboard surface of the counter weight  64 . It has been found that the presence of such a slightly tacky material may aid in reducing vibration or chattering in the hammer during normal operating conditions. Moreover, the presence of such a slightly tacky resin may aid in preventing the counter-weight  64  from rebounding back towards the neutral position upon impact against the raised step  56 . This avoidance of rebounding may be particularly beneficial during the occurrence of extremely high g-force events. 
         [0029]    By way of example only, and not limitation, a tacky resin such as an ultraviolet lightcurable resin or other similar material may be injected through a pinhole (not shown) in the housing  14  to fill a containment slot on the interior wall of the housing positioned in opposing relation to the hammer head outboard surface  76 . The injected resin may form a raised profile hammer head bumper  80  of slightly tacky character. The hammer head bumper  80  may be disposed in close spaced relation to the hammer head outboard surface  76  such that movement of the hammer head  60  in either direction will bring a portion of the hammer outboard surface  76  into contact with the hammer head bumper  80 . During normal operations, naturally occurring vibrations may cause the hammer  16  to oscillate about the pin  54  thereby bringing the hammer head outboard surface  76  periodically into contact with the hammer head bumper  80 . However, the presence of the slightly tacky hammer head bumper  80  will tend to dampen such oscillation by applying a drag on the movement of the hammer head  60  by virtue of the tacky surface character. 
         [0030]    As shown in  FIG. 10 , the hammer head bumper  80  may include a lower tail segment forming a free end  82  which projects below the containment slot. As will be appreciated, the free end  82  is pliable and may bend to some degree when subjected to substantial force applied by the hammer head  60  during a high g-force event. The tacky surface character of the hammer head bumper  80  will also act to grip the hammer head outboard surface  76  in the rotated condition, thereby prolonging the blocking period. 
         [0031]    A tacky resin such as an ultraviolet, light-curable resin or other similar material also may be injected through a pinhole (not shown) in the end cap  46  to fill a containment slot on the outboard surface of the raised step  56  positioned in opposing relation to the counter-weight  64 . The injected resin may form a raised profile counter-weight bumper  84  of slightly tacky character. When the hammer is rotated into blocking relation relative to the latching mechanism, the counter-weight bumper  85  assists in holding the hammer  16  in the rotated blocking position continuously throughout the entire force event. In a transportation vehicle this may include multiple impacts in different directions such as during a roll-over event or the like. In this regard, the tacky surface character of the counter-weight bumper  84  will act to grip the inboard surface of the counter-weight  64  in the rotated condition ( FIG. 10 ). This gripping action will act to reduce any rebound effects during a high g-force event and will act to prolong the active blocking period throughout the entire force event. However, spring  65  will urge the counter-weight  64  away from the counter-weight bumper  84  such that there is disengagement after the force event is concluded. The level of tackiness, and thus the duration of adhesion may be controlled by a combination of the force of spring  65  and the degree of curing the counter-weight bumper  84 . 
         [0032]    By way of example only, and not limitation, it is contemplated that the same resin material may be used to form both the hammer head bumper  80  and the counter-weight bumper  84 . However, different materials also may be used. One suitable resin material is a form-in-place and cure-in-place gasketing resin fluid marketed by DYMAX® Corporation of Torrington, Conn. under the trade designation GA-110 or GA 112. However, it is contemplated that any number of other injectable fluids providing a tacky surface character in a cured state also may be used if desired 
         [0033]    Of course, variations and modifications of the foregoing are within the scope of the present disclosure. All dimensions are merely exemplary. Thus, it is to be understood that the disclosure disclosed and defined herein extends to all alternative combinations of two or more of the individual features mentioned or evident from the text and/or drawings. All of these different combinations constitute various alternative aspects of the present disclosure.