Vehicle door latch security tether

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.

Claims

1. A vehicle comprising: a door; a latch assembly coupled to the door to selectively secure the door, the latch assembly comprising: a handle; a shaft; wherein the handle is coupled to the shaft to rotate the shaft about the shaft's longitudinal extent; a pawl attached to the shaft and movable between latched and unlatched conditions when the shaft is rotated, where when in the latched condition, a latch tab of the pawl is configured engage a securement on a compartment opening of the vehicle; a lock lever movable between locked and unlocked conditions, where 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; a security tether to prevent the shaft from moving the pawl when the lock lever is located in the locked condition, the security tether comprising: a plate attachable to the latch assembly; wherein the plate includes an aperture sized to receive at least a portion of the lock lever that is disposed through the aperture; wherein the plate includes a stop surface that limits movement of the lock lever; wherein the lock lever is movable relative to the stop surface; wherein at least the stop surface is spaced apart from the first location on the pawl; and wherein the lock lever engages the stop surface when the lock lever is located in the locked condition to prevent the pawl from moving to the unlatched condition.

2. The vehicle of claim 1, wherein the lock lever engages the first location on the pawl and the stop surface to prevent the pawl from moving to the unlatched condition and unlatching the latch assembly.

3. The vehicle of claim 1, wherein the stop surface is oriented non-parallel to a periphery surface of the aperture in the plate.

4. The vehicle of claim 1, wherein the plate is attachable to a pin on the lock assembly.

5. The vehicle of claim 1, wherein the plate does not move with respect to the pin or the lock lever.

6. The vehicle of claim 1, wherein the lock lever is movable by the lock cylinder that moves the lock lever about an axis.

7. A vehicle comprising: a door; a latch assembly coupled to the door to selectively secure the door wherein 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; wherein the first and second surfaces of the door are opposing sides of each other; wherein the latch assembly comprising: a shaft disposed through the first and second surfaces of the door; wherein the shaft rotates about its longitudinal extent; a pawl attached to the shaft and movable between latched and unlatched conditions when the shaft is rotated, where when in the latched condition, a latch tab of the pawl is configured engage a securement on a compartment opening of the vehicle; a lock lever spaced apart from the latch assembly and movable between locked and unlocked conditions, where 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; a security tether to prevent the shaft from moving the pawl when the lock lever is located in the locked condition, the security tether comprising: a plate attachable to the latch assembly; wherein the plate includes an aperture sized to receive at least a portion of the lock lever that is disposed through the aperture; wherein the plate includes a stop surface that limits movement of the lock lever; wherein the lock lever is movable relative to the stop surface; wherein at least the stop surface is spaced apart from the first location on the pawl; and wherein the lock lever engages the stop surface when the lock lever is located in the locked condition to prevent the pawl from moving to the unlatched condition.

8. The vehicle of claim 7, wherein the lock lever engages the first location on the pawl and the stop surface to prevent the pawl from moving to the unlatched condition and unlatching the latch assembly.

9. The vehicle of claim 7, wherein the stop surface is oriented non-parallel to a periphery surface of the aperture in the plate.

10. The vehicle of claim 7, wherein the plate does not move with respect to the pin or the lock lever.

11. The vehicle of claim 7, wherein the lock lever is movable by the lock cylinder that moves the lock lever about an axis.

12. The vehicle of claim 11, wherein at least a portion of the lock cylinder is disposed through the aperture.

13. A vehicle comprising: a door; a latch assembly located on the door, the latch assembly having a pawl movable between a latched and an unlatched condition, where when in the latched condition, a latch tab of the pawl is configured engage a securement on a compartment opening of the vehicle; a security tether configured to attach to the latch assembly to prevent the latch assembly from being moved to the unlatched condition when the latch assembly is in a locked state caused by a lock assembly being in a locked condition, the security tether comprising: a plate to attach to the latch assembly; wherein the plate includes a hole disposed through the plate, the hole being of a first diameter that is sized to receive at least a portion of the lock assembly disposed through the hole; wherein the lock assembly includes a lock cylinder assembly that pivots within the hole and a lock lever attached to and pivotable with the lock cylinder assembly, the lock assembly is pivotable between the locked condition and an unlocked condition; wherein the plate further includes a channel formed at a periphery of the hole to create a portion of the hole with a second diameter; wherein the first diameter is less than the second diameter; wherein the channel terminates at one end by a stop; and wherein the stop limits movement of the lock lever when the lock cylinder assembly is in the locked condition.

14. A vehicle comprising: a door; a latch assembly located on the door, the latch assembly having a pawl movable between a latched and an unlatched condition, where when in the latched condition, a latch tab of the pawl is configured engage a securement on a compartment opening of the vehicle; a security tether configured to attach to the latch assembly to prevent the latch assembly from being moved to the unlatched condition when the latch assembly is in a locked state caused by a lock assembly being in a locked condition, the security tether comprising: a plate to attach to the latch assembly; wherein the plate includes a hole disposed through the plate, the hole is sized to receive at least a portion of a lock assembly disposed through the hole; wherein a portion of the hole extends to the periphery of the plate forming an opening transverse to the longitudinal extent of the hole; wherein the lock assembly includes a lock cylinder assembly that pivots within the hole and a lock lever attached to and pivotable with the lock cylinder assembly, the lock assembly is pivotable between the locked condition and an unlocked condition; wherein the opening terminates at one end by a stop; and wherein the stop limits movement of the lock lever when the lock cylinder assembly is in the locked condition lock assembly.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present disclosure will be described hereafter with reference to the attached drawings which are given as non-limiting examples only, in which:

(2) 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;

(3) FIG. 2 is a front perspective view of a vehicle door latch;

(4) FIG. 3 is a rear perspective view of a vehicle door latch with a security tether attached;

(5) FIG. 4 is another prior art view of the prior art latch shown in locked and latched conditions;

(6) FIG. 5 is a rear perspective view of the prior art version of the latch assembly in a latched but unlocked condition;

(7) FIG. 6 is another rear perspective view of the prior art version of the latch assembly shown in both unlatched and unlocked conditions;

(8) FIG. 7 is an exploded view of the door latch assembly including a security tether for same;

(9) FIGS. 8A, 8B, and 8C are front perspective views and embodiments of security tethers;

(10) 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;

(11) 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;

(12) 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;

(13) FIG. 12 is a perspective view of the latch assembly with a security tether attached thereto;

(14) FIG. 13 is a different perspective view of the latch assembly with a security tether attached thereto;

(15) FIG. 14 is a top perspective view of the latch assembly with the security tether attached thereto;

(16) 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

(17) 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

(18) 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'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.

(19) 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'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.

(20) 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.

(21) 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.

(22) 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.

(23) 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.

(24) 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's movement.

(25) 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).

(26) 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.

(27) 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.

(28) 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.

(29) 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.

(30) 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.

(31) 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.

(32) 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.

(33) 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.

(34) 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.

(35) 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.

(36) 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.

(37) 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.