Abstract:
A vehicle that includes a door, handle, shaft, and a latch assembly is provided. The latch assembly is coupled to the door to selectively secure the door. The latch assembly includes a security tether configured to prevent the shaft from moving the pawl when the lock lever is located in the locked condition. The security tether further includes: a plate attachable to the latch assembly; the plate includes an aperture sized to receive at least a portion of the lock lever that is disposed through the aperture; the plate includes first and second stop surfaces to limit movement of the lock lever; the first and second stop surfaces are also spaced apart from each other; the lock lever is movable between the first and second stop surfaces; at least the first stop surface is spaced apart from the first location on the pawl; and the lock lever engages the first stop surface when the lock lever is located in the locked condition to prevent the pawl from moving to the unlatched condition and unlatching the latching assembly.

Description:
RELATED APPLICATIONS 
       [0001]    The present application relates to and claims priority to U.S. Provisional Patent Application, Ser. No. 62/073,608, filed on Oct. 31, 2014. The subject matter disclosed in that provisional application is hereby expressly incorporated into the present application. 
     
    
     BACKGROUND AND SUMMARY 
       [0002]    The present disclosure relates to work truck doors and latches, and in particular to a security tether for a vehicle compartment door latch. 
         [0003]    Conventional compartment door truck latches include a pivoting handle acting as a lever where moving it in one direction latches the door and moving in the opposite direction unlatches the door. The handle is attached to a latch shaft that is attached to a pawl that selectively engages or disengages a lock lever to lock or unlock the latch. Under normal circumstances, however, securement between the pawl and the lock lever is often not enough to prevent a forced engagement on the handle from unlatching the door. The combined resistance from the arm and latch is not, on its own, strong enough to withstand extreme forces and prevent failure. This obviously limits the effectiveness of this latching mechanism. 
         [0004]    An illustrative embodiment of the present disclosure provides a security tether which engages a portion of the pivot shaft attached to the handle and latch mechanism so that a force applied to the handle is absorbed by the tether to prevent the locking function from failing. In an embodiment, the security tether withstands a typical forced engagement applied by a human arm. If a tool is used to pry the handle and shaft, the security tether may cause a failure different from the prior art and instead the handle and shaft strip-out. The security tether, however, keeps the panel and, thus, the latch in place. This means that a forced incursion using tools on the handle will now only cause the handle to break but not unlatch the door. Such an intentional failure mechanism creates an additional level of security. 
         [0005]    Another illustrative embodiment of the present disclosure provides a vehicle that includes a door, handle, shaft, and a latch assembly. The latch assembly is coupled to the door to selectively secure the door. Further, the latch assembly includes: the handle being coupled to the shaft and configured to rotate the shaft about the shaft&#39;s longitudinal extent; a pawl is attached to the shaft and configured to move between latched and unlatched conditions when the shaft is rotated; a lock lever is movable between locked and unlocked conditions; when the lock lever is located in the locked condition, the lock lever engages the pawl at a first location so the pawl is prevented from moving to the unlatched condition; when in the unlocked condition, the lock lever is disengaged from the first location so the pawl is not prevented from moving to the unlatched condition; and a security tether configured to prevent the shaft from moving the pawl, when the lock lever is located in the locked condition. The security tether further includes: a plate attachable to the latch assembly; the plate includes an aperture sized to receive at least a portion of the lock lever that is disposed through the aperture; the plate includes first and second stop surfaces that limit movement of the lock lever; the first and second stop surfaces are also spaced apart from each other; the lock lever is movable between the first and second stop surfaces; at least the first stop surface is spaced apart from the first location on the pawl; and the lock lever engages the first stop surface when the lock lever is located in the locked condition to prevent the pawl from moving to the unlatched condition and unlatching the latch assembly. 
         [0006]    In the above and other embodiments, the vehicle may further include: the lock lever engaging the first location on the pawl and the first stop surface to prevent the pawl from moving to the unlatched condition and unlatching the latch assembly; the first and second stop surfaces being non-parallel to a periphery surface of the aperture in the plate; the plate being attachable to the pin on the lock assembly; the plate does not move with respect to the pin or the lock lever; and the lock lever is movable by a lock cylinder that moves the lock lever about an axis. 
         [0007]    Another illustrative embodiment of the present disclosure includes a vehicle that includes a door and a latch assembly. The latch assembly is coupled to the door to selectively secure the door. A first portion of the latch assembly is located on a first surface of the door and a second portion of the latch assembly is located on a second surface of the door. The first and second surfaces of the door are opposing sides of each other. The latch assembly also includes: a shaft disposed through the first and second surfaces of the door; the shaft being configured to rotate about its longitudinal extent; a pawl attached to the shaft and configured to move between latched and unlatched conditions when the shaft is rotated; a lock lever spaced apart from the latch assembly and movable between locked and unlocked conditions; when the lock lever is located in the locked condition the lock lever engages the pawl at a first location so the pawl is prevented from moving to the unlatched condition, and when in the unlocked condition, the lock lever is disengaged from the first location so the pawl is not prevented from moving to the unlatched condition; and a security tether configured to prevent the shaft from moving the pawl when the lock lever is located in the locked condition. The security tether includes: a plate attachable to the latch assembly; the plate includes an aperture sized to receive at least a portion of the lock lever that is disposed through the aperture; the plate further includes first and second stop surfaces to limit movement of the lock lever; the first and second stop surfaces are spaced apart from each other; the lock lever is movable between the first and second stop surfaces; at least the first stop surface is spaced apart from the first location on the pawl; and the lock lever engages the first stop surface when the lock lever is located in the locked condition to prevent the pawl from moving to the unlatched condition and unlatching the latch assembly. 
         [0008]    In the above and other embodiments, the vehicle may further include: the lock lever engaging the first location on the pawl and the first stop surface to prevent the pawl from moving to the unlatched condition and unlatching the latch assembly; the first and second stop surfaces being non-parallel to a periphery surface of the aperture in the plate; the plate does not move with respect to the pin or the lock lever; the lock lever being movable by a lock cylinder that moves the lock lever about an axis; and at least a portion of the lock cylinder being disposed through the aperture. 
         [0009]    Another illustrative embodiment of the present disclosure provides a vehicle that includes a door and a security tether. The security tether is configured to attach to a latch assembly on the door to prevent the latch assembly from being moved to an unlatched condition. The security tether includes a plate configured to attach to the latch assembly; the plate includes a hole disposed through the plate of a first diameter that is sized to receive at least a portion of a lock assembly that is disposed through the hole; the plate further including a channel formed at a periphery of the hole to create a portion of the hole to have a second diameter; the first diameter being less than the second diameter; the channel terminates at one end by a first stop and terminates at a second end by a second stop; and the first and second stops are spaced apart from each other and are configured to limit movement of the lock assembly. 
         [0010]    Another illustrative embodiment of the present disclosure provides a vehicle that includes a door and a security tether. The security tether is configured to attach to a latch assembly to prevent a latch assembly on the door from being moved to an unlatched condition. The security tether further includes a plate configured to attach to the latch assembly; the plate includes a hole disposed through the plate that is sized to receive at least a portion of a lock assembly that is disposed through the hole; a portion of the hole extends to the periphery of the plate forming an opening transverse to the longitudinal extent of the hole; the opening terminates at one end by a first stop and terminates at a second end by a second stop; and the first and second stops are spaced apart from each other and are also configured to limit movement of the lock assembly. 
         [0011]    Additional features of the present disclosure will become apparent to those skilled in the art upon consideration of illustrative embodiments including the best mode of carrying out the disclosure as presently perceived. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0012]    The present disclosure will be described hereafter with reference to the attached drawings which are given as non-limiting examples only, in which: 
           [0013]      FIG. 1  is a rear perspective view of a vehicle with a door incorporating a latch assembly of the type that is subject of the present disclosure; 
           [0014]      FIG. 2  is a front perspective view of a vehicle door latch; 
           [0015]      FIG. 3  is a rear perspective view of a vehicle door latch with a security tether attached; 
           [0016]      FIG. 4  is another prior art view of the prior art latch shown in locked and latched conditions; 
           [0017]      FIG. 5  is a rear perspective view of the prior art version of the latch assembly in a latched but unlocked condition; 
           [0018]      FIG. 6  is another rear perspective view of the prior art version of the latch assembly shown in both unlatched and unlocked conditions; 
           [0019]      FIG. 7  is an exploded view of the door latch assembly including a security tether for same; 
           [0020]      FIGS. 8A, 8B, and 8C  are front perspective views and embodiments of security tethers; 
           [0021]      FIG. 9  is a rear perspective view of the latch assembly with a tether attached thereto, wherein the latch assembly is in both latched and locked conditions; 
           [0022]      FIG. 10  is another rear perspective view of the latch assembly with a security tether attached thereto, wherein the latch assembly is in a latched but unlocked condition; 
           [0023]      FIG. 11  is another rear perspective view of the latch assembly with a security tether attached thereto, wherein the latch assembly is shown in unlatched and unlocked conditions; 
           [0024]      FIG. 12  is a perspective view of the latch assembly with a security tether attached thereto; 
           [0025]      FIG. 13  is a different perspective view of the latch assembly with a security tether attached thereto; 
           [0026]      FIG. 14  is a top perspective view of the latch assembly with the security tether attached thereto; 
           [0027]      FIGS. 15A, 15B and 15C  include perspective and detail views of the latch assembly showing the effects on the latch assembly when excessive force is used when a security tether is and is not used; and 
           [0028]      FIGS. 16A and 16B  are front and top views of a security tether showing illustrative dimensions thereto for use on illustrative door latches. 
       
    
    
     DETAILED DESCRIPTION 
       [0029]    A rear perspective view of an illustrative embodiment of a vehicle, such as pickup truck  1 , is shown in  FIG. 1 . This view depicts truck  1  having a passenger compartment  3  and a cap  5  covering the truck&#39;s rear bed. Cap  5  also includes illustrative doors  7  and  9  which swing open to allow access to the interior of the rear bed. Vehicle door latch assembly  2  is shown on door  7  and  9  to secure and lock said doors to vehicle  1 . Actuating latch  2  releases the door to allow it to swing or otherwise move to the open condition. When latch  2  is latched and locked, the door is prevented from opening unless force can be applied to the latch and/or lock to overcome the locking function of the lock. 
         [0030]    A front perspective view of vehicle door latch assembly  2  is shown in  FIG. 2 . These latches are commonly used on compartment doors for commercial and industrial vehicles, such as lifts and work trucks, to secure the compartment door or the like. Typically these latches, from the operator&#39;s point of view, include a main housing  4  with a pivotable handle  6  that is both recessible in and extendible from housing  4 . During operation, handle  6  is pivoted upward in direction  8 . Handle  6  is attached to shaft  16  so both are rotatable in the same direction  12 . This causes pawl  18  with latch tab  20  attached thereto to rotate in direction  12  and unlatch the door (not shown). Conversely, to relatch the door, handle  6  is turned in direction  14  which likewise turns shaft  16  which rotates pawl  18  and latch tab  20  in direction  14 . Tab  20  reengages a securement (not shown) on the periphery of the compartment opening to latch the door (also not shown) closed. With the door latched, handle  6  may be pushed downward in direction  10  into cavity  22  of housing  4  so as not to become an obstruction while operating the vehicle. To lock latch assembly  2 , a lock cylinder assembly  24  extends through housing  4  and is engageable with a key (not shown) which rotates between lock and unlock conditions. The problem with this design is that the rotational force that can be applied to shaft  16  from handle  6  may be stronger than what the structure associated with lock cylinder assembly  24  can withstand. This makes the locking system vulnerable. 
         [0031]    An embodiment of the present disclosure herein includes a tether structure  30  (see  FIG. 3 ) that provides the needed strength so that excessive force on shaft  16  will not be able to overcome the locking and latching features. It is contemplated that security tether  30  is able to be added to latch assembly  2  as an add-on. This makes the fix both relatively simple and affordable in contrast to purchasing complete new latch assemblies. 
         [0032]    A rear perspective view of vehicle door latch assembly  2  is shown in  FIG. 3 . This view further shows pawl  18 , latch tab  20 , and lock cylinder assembly  24 . Also shown is lock lever  26  located in unlocked and latched conditions. It is appreciated that the key that turns a portion of lock cylinder  24  rotates lock lever  26  between locked and unlocked conditions. The locked condition is configured (as further disclosed herein) to lock pawl  18  keeping it from moving. This view also shows the head portion of bolt  28  which is attached to the aforementioned shaft  16  to provide the pivot point for pawl  18 . 
         [0033]    What is new to latch assembly  2  is the addition of security tether  30  with bolt  28  and spacer  90 . This tether couples to both shaft  16  and lock lever  26  about lock cylinder assembly  24  to prevent excessive rotational force on shaft  16  from breaking lock cylinder  24 , thereby lock lever  26  unlocking and unlatching latch assembly  2 . 
         [0034]    A rear perspective view of a prior art version of latch assembly  2  is shown in  FIGS. 4 through 6 . These views do not include security tether  30 . As shown in  FIG. 4 , pawl  18  locates latch tab  20  in the latched condition. Additionally, lock cylinder assembly  24  has pivoted lock lever  26  in a locked condition. In this state, lock lever  26  is positioned in cavity  32  formed in pawl  18 . Cavity wall portion  34  is configured to engage lock lever  26  such that if an attempt is made to rotate pawl  18  in direction  12 , lock lever  26  engages cavity wall portion  34  preventing that movement from happening. As can be appreciated, however, overcoming that engagement between lock lever  26  and cavity wall portion  34  is all that is needed to overcome the locking function. It is further appreciated that pawl  18  is formed out of a piece of relatively thin metal so the force needed to overcome that engagement is not all that great. The prior art view in  FIG. 5  shows lock lever  26  in the unlocked condition. Pawl  18  and tab  20  are still located in the latched condition, but they are free to rotate if shaft  16  is rotated. The prior art view in  FIG. 6  shows handle  6  rotated, which rotates shaft  16  and pivots pawl  18  and tab  20  in direction  12  to an unlatched condition. It is appreciated from this view that tab  20  simply needs to be moved to this position to unlatch the door. Overcoming lock lever  26  is all that is needed to unlatch assembly  2  without a key. 
         [0035]    An exploded view of vehicle door latch assembly  2  that includes security tether  30  is shown in  FIG. 7 . As depicted, handle  6  is pivotally coupled to shaft  16  via handle rivet  36  disposed through coincident openings  38  and  40 . To seal shaft  16  from exterior to interior, shaft gasket  42 , along with shaft cover gasket  44  and shaft cover  48 , surround shaft  16 . Housing  4  includes a bore opening  50  that receives shaft  16  so it can be located on both the front and rear side of latch  2 . Also shown is lock cylinder assembly  24  that extends through cylinder gasket  52  and bore  54  in housing  4  to extend between front and rear sides of housing  4 . A flange  54  includes openings  56  and  58  and is secured onto housing  4  via rivet  60 . A hex nut  62  secures lock cylinder assembly  24  to housing  4  and lock lever  26  secures to lock cylinder  24  via e-ring  64 . Shaft  16  also extends through opening  58  of flange  54  and secures to latch  2  via shaft e-ring  66  and bolt  28 . Pawl  18  pivotally secures to latch assembly  2  via shaft  16  that extends through opening  68 . A washer  70  may be disposed about shaft  16  between pawl  18  and flange  54  to assist in pivotal movement of same. Rod posts  74  and  76  are configured to attach to pawl  18 , as well as lock rods  78  and  80 . Set screws  82  secure rods  78  and  80  to posts  74  and  76 , respectively. A cam rivet  84  is secured to pawl  28  in order to limit pawl  18 &#39;s movement. 
         [0036]    Security tether  30 , having openings  88  and  92  disposed therethrough, is coupled to latch assembly  2  via bolt  28 . A spacer  90 , as well as bolt  28 , spaces apart tether  30  from pawl  18  and cam washer  86  (see also  FIG. 13 ). 
         [0037]    There are essentially three failure modes for the prior art version of latch assembly  2 . The first is where the axes of both shaft  16  and lock cylinder  24  splay themselves apart when pawl  18  is rotated in direction  12 . This is caused by wall portion  34  of pawl  18  pushing against lock lever  26  when force is being applied towards direction  12 . Another failure mechanism is when a force on pawl  18  is applied in direction  12  causing wall portion  34  of pawl  18  to engage lock lever  26  causing excessive force on retainer  106  and e-ring  64 . This torsion force causes both structures to fail which essentially allows lock lever  26  to “pop” off of lock cylinder  24 . This allows pawl  18  to be moveable. A third failure mechanism occurs when applying excessive force against pawl  18  in direction  12 , causing wall portion  34  of pawl  18  to apply a force against lock lever  26 . But instead of retainer  106  failing, the internal locking structures in lock cylinder  24  strip, thereby causing lock lever  26  to be moveable to the unlocked condition and allowing pawl  18  to move and unlatch. The embodiments of the security tether keep the axis of shaft  16  (with bolt  28 ) and lock cylinder  24  substantially parallel to each other under excessive force preventing the first failure mechanism as described above. In addition, the tethers absorb the force applied to lock lever  26  by wall portion  34  of pawl  18 , thereby preventing the failure of lock lever  26  by either the second or third failure mechanisms described above. 
         [0038]    Front perspective views of embodiments of security tethers  30 ,  100 , and  105  are shown in  FIGS. 8A, 8B, and 8C  respectively. These security tethers may be made of a solid piece of metal, such as steel, aluminum, brass, or other materials, such as high density polyethylene or a laminate. Openings  88  and  92  receive the lock cylinder and shaft, respectively, as previously discussed. As part of opening  88 , there is a lever slot portion  94  that receives lock lever  26 . Slot portion  94  is configured to accommodate rotational travel of lock lever  26  between locked and unlocked conditions. By providing a strengthened tie between shaft  16  and lock cylinder  24 , forced rotation of shaft  16  can no longer overcome lock lever  26 . Each of the embodiments  30 ,  100 , and  105  shown in  FIGS. 8A-C  includes opening  88  and slot portion  94  terminating at edges  96 . In addition, along the periphery of opening  88  are wall portions  107  and  108 . 
         [0039]    Edge  96  on lever slot portion  94  now receives the force of lock lever  26  instead of the force received by retainer  106  and e-ring  64 . This means first, there is a strong reinforcement to hold the locked condition, and second, any strong forces applied to edge  96  through shaft  16  will cause a failure at the shaft instead of at the lock, and particularly at the pawl. Accordingly, any failure due to excess force will not occur at the pawl nor the retainer and clip and, thus, not move latch tab  20 . 
         [0040]    Surface  107  on the embodiments keeps the tether positioned against the lock cylinder  24  (see also  FIGS. 4 and 9 ) so that if an excessive force applied to pawl  18  in direction  12  causes wall portion  34  to act on lock lever  26 , edge  96  engages lock lever  26 , but that force is offset by engagement of surface  107  against lock cylinder  24 . Surface  108  in the embodiments keep shaft  16 /bolt  28  and lock cylinder  24  substantially parallel to prevent them from splaying. If any excessive force is applied to handle  6 , shaft  16  will only strip-out or break those structures, while latch  2  remains latched. 
         [0041]    Security tether  100 , from  FIG. 8B , is similar to that shown in embodiment  30  except that opening  88  and slot  94  are shifted in order to accommodate a lock cylinder of different configuration. This embodiment shows opening  98  configured to accept a 20 degree lock lever. It is appreciated that the angle of opening  98  may be set to any degree and is not limited to a 20 degree lock lever. 
         [0042]    Security tether  105  included in  FIG. 8C  with tether  30  (see  FIG. 8A ) is another embodiment having an “open” version where part of the material forming slot  94  has been removed. In any event, the wall portions  95 ,  107 , and  108  are still there and serve the same functions as those portions in tethers  30  and  100 . 
         [0043]    Rear perspective views of assembly  2 , as shown in  FIGS. 9 through 11 , are similar to the prior art views of  FIGS. 3 through 5  except with security tether  30  attached to shaft  16  via bolt  28 . Also, tether  30  is located about the periphery of lock cylinder  24  with lever slot portion  94  accommodating lock lever  26 . As shown in  FIG. 9 , lock lever  26  is located in the locked condition with pawl  18  and tab  20  located in the latched condition. In this view, it is appreciated that if shaft  16  attempts to rotate pawl  18  in direction  12 , lock lever  26  engages edge  96  of tether  30  which will prevent any movement. The views in  FIGS. 10 and 11  demonstrate how security tether  30  does not interfere with lock lever  26  as lock cylinder  24  moves it to the unlocked condition (see  FIG. 10 ). Handle  6  rotates pawl  18  in direction  12  to move tab  20  to the unlatched condition. In other words, the operation of latch  2  may progress as normal without any interference from security tether  30 . It is only when forced movement of shaft  16  attempts to break open latch  2  does security tether interfere with operation of pawl  18  and lock lever  26 . 
         [0044]    Latch assembly  2 , shown in  FIGS. 12 through 14 , depicts security tether  30  coupled thereto from different angles. It is appreciated from these views that security tether  30  is configured to just slide over lock cylinder  24  and secure onto shaft  16  via bolt  28 . Accordingly, retrofitting current similar-type latches is a relatively easy task. 
         [0045]    The views shown in  FIGS. 15A through 15C  demonstrate what happens if excessive force is applied to shaft  16  in order to break latch  2 . In  FIG. 14A , shaft  16  is located in opening  68  of pawl  18 . In this illustrative embodiment, both this portion of shaft  16  and its corresponding opening  68  are square-shaped. It is appreciated that in other embodiments they are not limited to square shape. With security tether  30  in operation, it is shaft  16  that strips out while pawl  18  does not move. The view shown in  FIG. 14B  depicts the result of applying too much force to shaft  16  with security tether  30  in place. It is appreciated that this view has removed security tether  30  for illustrative purposes to show what happens to shaft  16  and opening  68  as a result of an applied break-in force. A detailed view of shaft  16  and opening  68  in  FIG. 14C  demonstrates how both structures are stripped out so that shaft  16  can rotate with respect to opening  68  yet not move pawl  18 . When this happens, rotation of shaft  16  will fail to rotate latch tab  20  which maintains itself in a latched condition. 
         [0046]    Illustrative dimensions of an embodiment of security tether  30  are shown in  FIGS. 16A and 16B . It is appreciated that these dimensions are illustrative. It is further appreciated that the position of the openings may be changed based on the desired configuration of the latch and lock assembly it is attaching to. 
         [0047]    The figures and descriptions provided herein may have been simplified to illustrate aspects that are relevant for a clear understanding of the herein described devices, systems, and methods, while eliminating, for the purpose of clarity, other aspects that may be found in typical devices, systems, and methods. Those of ordinary skill may recognize that other elements and/or operations may be desirable and/or necessary to implement the devices, systems, and methods described herein. Because such elements and operations are well known in the art, and because they do not facilitate a better understanding of the present disclosure, a discussion of such elements and operations may not be provided herein. However, the present disclosure is deemed to inherently include all such elements, variations, and modifications to the described aspects that would be known to those of ordinary skill in the art. 
         [0048]    Although certain embodiments have been described and illustrated in exemplary forms with a certain degree of particularity, it is noted that the description and illustrations have been made by way of example only. Numerous changes in the details of construction, combination, and arrangement of parts and operations may be made. Accordingly, such changes are intended to be included within the scope of the disclosure, the protected scope of which is defined by the claims.