Exemplary embodiments of the present invention relate generally to a vehicle door latch system and more particularly, to a vehicle door latch system configured to keep door latch mechanisms from unlatching during one or more predetermined events.
A vehicle closure, such as a door for a vehicle passenger compartment, is hinged to swing between open and closed positions (e.g., passenger and driver side doors, lift gates, etc.) or slide between an open and closed position along a guide track (e.g., sliding doors for vans) and conventionally includes a door latch that is housed between inner and outer panels of the door. The door latch functions in a well-known manner to latch the door when it is closed and to lock the door in the closed position or to unlock and unlatch the door so that the door can be opened manually or powered.
The door latch is operated remotely from the exterior of the automobile by at least two distinct operators, a key cylinder that controls the lock mechanism and an outside door handle or push button that controls the release mechanism.
The door latch is also operated remotely from inside the passenger compartment by at least two distinct operators, a sill button that controls the lock mechanism and an inside door handle that controls the release mechanism. Vehicle door latches may also include power door locks in which the lock mechanism is motor driven and/or a keyless entry in which a key fob transmitter sends a signal to a receiver in the vehicle to operate a motor driven lock mechanism.
The door latch type noted above operates in a well-known manner. However, there is a desire to make further improvements in door latches of the above noted type, including other variations of door latches that are well known. More specifically, there is a desire to make a door latch system designed to keep door latch mechanisms from unlatching during one or more predetermined events for a predetermined time period. It is also desirable for designing a door latch system that utilizes any or all vehicle sensors allowing the latch mechanism to engage and prevent the latch from mechanically releasing during the predetermined event.
Thus, in accordance with exemplary embodiments of the present invention there is provided a vehicle door latch system configured to prevent a latch mechanism from unlatching when one or more variables during one or more predetermined events are detected and exceed a locking threshold for a predetermined time period.
In one exemplary embodiment, a vehicle door latch system configured to prevent door latch mechanisms from unlatching during a predetermined event is provided. The door latch generally includes a forkbolt pivotally mounted to a housing portion of the vehicle door latch, the forkbolt being capable of movement between a latching position and an unlatching position. The door latch also includes a block out mechanism configured for movement between a blocking position and an unblocking position, the block out mechanism being configured to prevent the forkbolt from moving from the latching position to the unlatching position when the block out mechanism is in the blocking position, the block out mechanism being biased into the unblocking position by a biasing member. The door latch also includes an activation mechanism for moving the block out mechanism to the blocking position when the activation mechanism is activated for a predetermined time period to overcome the biasing member and after the predetermined time period, the block out mechanism moves to the unblocking position by the biasing member.
In another exemplary embodiment, a method of preventing movement of a forkbolt mounted to a housing portion of a vehicle door latch is provided, the method comprising: biasing a block out mechanism into an unblocking position by a biasing member, the block out mechanism allowing the forkbolt to move between a latching position and an unlatching position when the block out mechanism is in the unblocking position; and moving the block out mechanism into a blocking position for a predetermined time period by temporarily overcoming the biasing member by the activation of an activation mechanism, the block out mechanism being configured to prevent the forkbolt from moving from the latching position to the unlatching position when the block out mechanism is in the blocking position and after the predetermined period of time, the block out mechanism moves to the unblocking position by the biasing member.
In another exemplary embodiment a method of preventing movement of a forkbolt mounted to a housing portion of a vehicle door latch is provided, the method comprising: biasing a block out mechanism into an unblocking position by a biasing member, the block out mechanism allowing the forkbolt to move between a latching position and an unlatching position; detecting the occurrence of at least one variable during at least one predetermined event by at least one sensor; sending a signal to an electronic control module when the at one variable during the at least one predetermined event is detected to activate an activation mechanism, the electronic control module is configured to determine if the at least one variable exceeds a locking threshold, the activation mechanism activates when the electronic control module determines that the at least one variable exceeds the locking threshold; and moving the block out mechanism into a blocking position for a predetermined time period by temporarily overcoming the biasing member when the activation mechanism is activated, the block out mechanism being configured to prevent the forkbolt from moving from the latching position to the unlatching position when the block out mechanism is in the blocking position and after the predetermined period of time, the block out mechanism moves to the unblocking position by the biasing member.
Exemplary embodiments of the present invention are directed to a vehicle door latch system configured to temporarily prevent door latch mechanisms of a door latch from unlatching when one or more variables during one or more predetermined events are detected and exceed a locking threshold. Specifically, the exemplary embodiments of the present invention are directed to a vehicle door latch system configured to temporarily prevent the movement or the unlatching of a forkbolt pivotally mounted to a housing of a vehicle door latch by temporarily preventing the movement or the unlatching of a detent from the forkbolt when one or more variables during one or more predetermined events are detected and exceed a locking threshold. The predetermined events that may occur include, but are not limited to, high inertial loading, G-forces, and linkage activation releases, which are not attributable to normal latch operation (e.g. desired opening and closing). The one or more variables that may be detected include, but are not limited to rapid vehicle acceleration and/or deceleration and deformation of crumple zones in a vehicle.
A vehicle door latch is described in U.S. Pat. No. 5,277,461, the contents of which are incorporated herein by reference thereto. The door latch disclosed in the '461 patent includes an unlatching lever pivotally mounted on a stud that is secured to a metal back plate and a metal face plate at opposite ends. The unlatching lever unlatches the vehicle door by an inside handle lever that is connected by a suitable linkage for rotation by an inside door handle.
The door latch of the '461 patent also includes a locking lever that is pivotally mounted on the stud. The locking lever is operated by an inside locking lever that is pivotally mounted on the flange of the metal face plate near the inside handle lever. The inside locking lever is operated by an inside sill button or lock slide through a suitable linkage. The locking lever is also operated by an outside locking lever that is operated by a key lock cylinder through a suitable linkage. In one exemplary embodiment, the locking lever is power operated by a remotely controlled linear electric motor or the like in a well-known manner.
The door latch disclosed in the '461 patent is unlocked and unlatched in the following sequence. First the locking lever is moved to the unlocked position by the inside locking lever, the outside locking lever, or in the instance of a vehicle equipped with power door locks, a remotely controlled motor. This moves the intermittent lever to the unlocked position. After the door latch is unlocked, the door latch is unlatched by moving the unlatching lever via inside handle lever or outside handle lever to the unlatched position pulling intermittent lever and detent down to unlatch the door lock. The vehicle door then may be pushed or pulled open manually.
U.S. Pat. No. 5,308,130, the contents of which are incorporated herein by reference also discloses a vehicle door latch.
Referring now to
In accordance with an exemplary embodiment, door latch 12 includes a latch mechanism comprising a forkbolt 24 and a cooperating detent 26 that are located in the forward compartment and pivotally mounted on the forward portions of studs 18 and 20 respectively as illustrated in
The door latch 12 includes a release mechanism (not shown) for releasing or unlatching the latch mechanism as generally described above and a locking mechanism (not shown) for disabling the release mechanism, which are both generally located in the rear compartment defined by housing portion 14. Details of the structure and operation of the release mechanism and the lock mechanism are also not necessary for an understanding of the exemplary embodiments of the present invention except to know the general operation of the latch mechanism as described above. However, for a detailed explanation of a suitable latch mechanism, a release mechanism, and a lock mechanism, that could be used in accordance with an exemplary embodiment of the present invention see U.S. Pat. No. 6,053,543, the contents of which are incorporated herein by reference thereto.
In a non-limiting exemplary embodiment, a block out mechanism 40 is installed within housing portion 14 of door latch 12. As illustrated in
Door latch 12 also includes a block out return spring 52. Still referring to
In an exemplary embodiment, door latch 12 includes an activation mechanism 54. As illustrated in
The activation mechanism 54 is configured to temporarily overcome the biasing force of block out return spring 52. This will become more apparent with the details that follow. In one non-limiting exemplary embodiment, activation mechanism 54 is a metal wire composed of one or more alloys having superior deformable properties. Suitable types of materials, such as shape memory alloys for activation mechanism 54 can be constructed out of include, but are not limited to, copper-zinc aluminum alloys, copper-aluminum-nickel alloys, and nickel-titanium alloys. In a preferred embodiment, nickel-titanium alloys are used to construct activation mechanism 54.
The superior deformable properties possessed by activation mechanism 54 allow activation mechanism 54 to deform from one length or its original length to another length less than its original length when a force is applied to activation mechanisms 54. In one exemplary embodiment, activation mechanism 54 deforms from one length to another length when heat is applied directly or indirectly to it or when the temperature of activation mechanism 54 is reduced to a deformable temperature. The activation mechanism 54 begins to deform from its original length to a length less than the original at above its phase transition temperatures. The activation mechanism 54 is configured to return back to its original length upon cooling or below at its phase transition temperature. The length of activation mechanism can be shortened by at least four percent its original length.
When heat deforms activation mechanism 54 to a length less than its original length, the output force, ranging from ones to hundred grams, is temporarily applied to second arm 46 of block out mechanism 40 for a predetermined time period. Of course, the amount of force can vary as required by applications of exemplary embodiments of the present invention. The predetermined time period will depend on the pre-detected events and the construction of the activation mechanism 54, such as materials, shape, dimensions, and power applied. The output force applied to block out mechanism 40 caused by activating the activation mechanism 54 rotates block out mechanism 40 clockwise and overcomes the biasing force of block out return spring 52 for a predetermined time period. In doing so, block out mechanism 40 is moved in the blocking position for the predetermined time period. During that predetermined time period, contact feature 32 of detent 26 remains engaged with shoulder 28 or shoulder 30 of forkbolt 24. After the predetermined time period, block out mechanism 40 is moved back to the unblocking position. In this instance, detent 26 is free to rotate counterclockwise in the releasing position and remove itself from engagement with shoulder 28 or shoulder 30 of forkbolt 24. This allows forkbolt 24 to freely rotate counterclockwise in the unlatching position.
Referring back to
Still referring to
In one exemplary embodiment, sensor 64 is configured to indicate one or more of the predetermined events by detecting one or more variables described above. When one or more variables during one or more predetermined events are detected by sensor 64, sensor 64 sends the signal to electronic control module 60. This activates electronic control module 60 to determine whether or not the one or more variables exceed the locking threshold. If so, the electronic control module 60 provides voltage to activation mechanism 54 for a predetermined time period. The voltage sent to deform activation mechanism 54 ranges from 1 to 120V, typically from 1 to 12V. Once voltage is provided to activation mechanism 54, the length of activation mechanism 54 deforms to a length shorter than its original length for a predetermined time period. During this predetermined time period, activation mechanism 54 temporarily applies output force to second arm 46 of block out mechanism 40, thereby having block out mechanism 40 overcome the biasing force of block out return spring 52. Accordingly, block out mechanism 54 prevents contact feature 32 of detent 26 from disengaging with shoulder 28 or shoulder 30 of forkbolt 24.
It should be understood that electronic control module 60 can be in signal communication with additional sensors, similar or different from sensor 64, that are capable of indicating one or a combination of predetermined events.
In accordance with an exemplary embodiment of the present invention, an exemplary method of preventing movement of forkbolt 24 during a predetermined event is provided. In this exemplary method, contact feature 32 of detent 26 engages with shoulder 28 of forkbolt 24 as illustrated in
In an alternative exemplary embodiment, and as illustrated by the dashed lines in
While the invention has been described with reference to an exemplary embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but that the invention will include all embodiments falling within the scope of the present application.
This application claims the benefit of the following U.S. Provisional Patent Application, Ser. No. 60/972,453, filed Sep. 14, 2007, the contents of which are incorporated herein by reference thereto.
Number | Date | Country | |
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60972453 | Sep 2007 | US |