Exemplary embodiments of the present invention relate to door and movable panel latches and, more particularly, to door and movable panel latches for vehicles.
A vehicle frequently includes displaceable panels such as doors, hood, trunk lid, hatch and the like which are affixed for hinged or sliding engagement with a host vehicle body. Cooperating systems of latches and strikers are typically provided to ensure that such panels remain secured in their fully closed position when the panel is closed.
A door latch typically includes a fork bolt that is pivoted between an unlatched position and a primary latched position when the door is closed to latch the door in the closed position. The fork bolt is typically held in the primary latched position by a detent lever that pivots between an engaged position and a disengaged position. The detent lever is spring biased into the engaged position and thus, holds the fork bolt in the primary latched position when in the engaged position and releases the fork bolt when it is moved to the disengaged position so that the door can be opened.
The fork bolt is pivoted to the primary latched position by a striker attached to, for example, an associated door jamb when the door is closed. Once in the primary latched position, the detent lever engages the fork bolt to ensure the assembly remains latched.
Accordingly, it is desirable to provide a latch assembly wherein the detent lever is prevented from inadvertently being moved into a disengaged position.
In accordance with one exemplary embodiment of the invention, a latch assembly is provided. The vehicle latch assembly having: a fork bolt movably secured to the latch assembly, the fork bolt being capable of movement between a latched position and an unlatched position; a detent lever movably secured to the latch assembly, the detent lever being capable of movement between an engaged position and a disengaged position, the detent lever retains the fork bolt in the latched position when the detent lever is in the engaged position and an engagement surface of the detent lever contacts an engagement surface of the fork bolt; an inertia block out assembly for preventing the detent lever from moving into the disengaged position when the inertia block out assembly is in a blocking position; and a manual override mechanism for the inertia block out assembly, wherein the manual override mechanism requires at least three independent actions to be performed to move the inertia block out assembly from the blocking position to an unblocking position, wherein the detent lever is capable of being moved from the engaged position to the disengaged position when the inertia block out assembly is in the unblocking position.
In an alternative embodiment, a method of preventing a detent lever of a vehicle door latch assembly from moving to a disengaged position when the detent lever has been moved to an engaged position by a remotely activated actuator is provided. The method including the steps of: pivotally securing a fork bolt to the vehicle door latch assembly for movement between an unlatched position and a latched position; pivotally securing the detent lever to the vehicle door latch assembly for movement between the engaged position and the disengaged position wherein a contact surface of the detent lever engages a contact surface of the fork bolt when the detent lever is in the engaged position and the fork bolt is in the latched position; preventing the detent lever from moving into the disengaged position from the engaged position until an inertia block out assembly of the vehicle door latch is moved from a blocking position to an unblocking position; and moving the inertia block out assembly from a blocking position to an unblocking position, by a manual override mechanism, wherein the manual override mechanism requires at least three consecutive independent actions to be performed to move the inertia block out assembly from the blocking position to an unblocking position, wherein the detent lever is capable of being moved from the engaged position to the disengaged position when the inertia block out assembly is in the unblocking position.
In an alternative embodiment, a vehicle door latch assembly is provide, the vehicle door latch assembly having: a fork bolt movably secured to the latch assembly, the fork bolt being capable of movement between a latched position and an unlatched position; a detent lever movably secured to the latch assembly, the detent lever being capable of movement between an engaged position and a disengaged position, the detent lever retains the fork bolt in the latched position when the detent lever is in the engaged position and an engagement surface of the detent lever contacts an engagement surface of the fork bolt; an inertia block out assembly for preventing the detent lever from moving into the disengaged position when the inertia block out assembly is in a blocking position; and a manual override mechanism for the inertia block out assembly, wherein the manual override mechanism requires at least two consecutive independent actions to be performed to move the inertia block out assembly from the blocking position to an unblocking position, wherein the detent lever is capable of being moved from the engaged position to the disengaged position when the inertia block out assembly is in the unblocking position.
Additional features and advantages of the various aspects of exemplary embodiments of the present invention will become more readily apparent from the following detailed description in conjunction with the drawings wherein like reference numerals refer to corresponding parts in the several views.
Although the drawings represent varied embodiments and features of the present invention, the drawings are not necessarily to scale and certain features may be exaggerated in order to illustrate and explain exemplary embodiments the present invention. The exemplification set forth herein illustrates several aspects of the invention, in one form, and such exemplification is not to be construed as limiting the scope of the invention in any manner.
Exemplary embodiments of the present invention relate to an apparatus and method for providing a latch assembly. Furthermore, exemplary embodiments are directed to a latch assembly having a fork bolt movably secured thereto for movement between a latched position and an unlatched position. The latch assembly further comprises a detent lever capable of movement between an engaged position and a disengaged position, the detent lever retains the fork bolt in the latched position when the detent lever is in the engaged position and an engagement surface of the detent lever contacts an engagement surface of the fork bolt. The latch assembly also includes an inertia block out assembly for preventing the detent lever from moving into the disengaged position until a predetermined force is applied to the detent lever to move it to the disengaged position when the fork bolt is in the latched position.
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.
In general terms, the door latch has a forkbolt that engages a striker in the door jamb to latch the door when it is closed and a spring biased detent lever that engages and holds the forkbolt in the latched position. The door latch also typically has a release mechanism for moving the detent to a position releasing the forkbolt so that the door can be unlatched and opened and a lock-unlock mechanism for disabling the release mechanism to prevent unauthorized unlatching of the door.
In one non-limiting exemplary embodiment, the latch assembly is configured to block the detent lever in order to avoid any undesired opening especially when the latch or detent lever could be exposed to a high acceleration.
Reference is made to the following U.S. Pat. Nos. 3,969,789; 6,053,543 and 6,568,741 and U.S. Patent Publication No. 2002/0163207 the contents each of which are incorporated herein by reference thereto.
Inertia mechanisms have long been applied to vehicle door latch systems in an effort to control the motion of internal components in the event of a crash condition that would otherwise serve to retain the door to the body of the vehicle.
Since the structural and release mechanisms of most vehicle latches are manufactured from steel or structural thermoplastic resin, they all are susceptible to this form of inertial load and thus can release inadvertently.
Some forms of inertia mechanisms employ the use of a counter-balancing mass on a lever that, when a specified level of inertia is encountered, will translate or rotate a blocking member to effectively block out a specific latch or handle component resulting in an enhanced level of inertia performance. Other forms of inertia enhancement systems rely on electromechanical means (motor and gears, solenoid, etc.) to translate or rotate the aforementioned blocking member.
Both of the systems mentioned above have limitations such as the vector to which the inertia is applied, the level of inertia, corrosion, and system deformation.
One possible solution to the aforementioned inertial energy application is to employ a responsive system, much like air bag technology that is currently used in nearly every new vehicle produced. This type of system would react to energy levels instantaneously applied to the vehicle via a response from a form of sensory signal. Issues arise with this methodology due to the time required for said sensory event. Data shows that inertial loads created in a side impact crash event can happen nearly instantaneously, often breaching 10 mS. This brings into light the necessity of a reactive system that can sense, process and deliver an electric signal to a device that could effectively enhance the ability of a door latch system to retain the passenger door of a vehicle in this time window. Experts agree that the process time alone of such a system would be greater than the 10 mS target, thus making them ineffective for all side impact events.
Another sort of inertial energy mitigation device could come in the form of a more active system that senses the vehicles motion or velocity, as an example, to engage an electromechanical system. This approach could greatly enhance the capability of any vehicle to withstand, not only greater inertial loads from a crash or rollover event, but to withstand undesired release activation due to deformation of the vehicle body or the related mechanical release system. This deformation can also cause the aforementioned inadvertent release of a vehicle door latching system.
In either case, a reactive or active system, the desire is to be able to release the system after a crash event occurs. This would ease the egress of passengers possibly trapped in the vehicle after a crash or rollover event. This would entail a system that would reset itself after an event, or be capable of being mechanically overridden when desired.
It is therefore the purpose of this application, to define a desired system capability, and a method to achieve the desired performance. In addition, this application will describe a method of mechanically overriding a crashworthiness enhancement system, such that a passenger in a vehicle that encountered a crash or rollover event can release the latching system post-event.
For the purposes of this application, consider a conventional vehicle door latch construction that employs a structural feature rigidly secured to the body of the vehicle (striker), a rotating structural member within the door latch construction that engages with the striker (forkbolt lever) and another rotating structural member that engages with the forkbolt to constrain the forkbolt in a closed position (detent lever). By moving the detent to an open position, the forkbolt is then free to rotate to an open position, thus releasing the door from the body of the vehicle.
In accordance with various exemplary embodiments of the present invention, the detent lever, or other member of the latch release mechanism, is restrained from moving towards its open position due to the effects of high inertia forces or external forces applied to the release chain due to body deformation or release cable or rod deformation often encountered during a vehicle crash or rollover event.
In addition and as will be explained herein possible control methodologies with which to activate and deactivate the system are also contemplated.
Still further, a manner of manually disengaging the detent restraining device in the event of a loss of power to the mechanism will be described.
The door latch release mechanism in the context of the aforementioned description is any member or combination of members that are kinematically coupled to the detent lever so to move it to its open position. Hundreds of previous patents and publications attest to the possible combinations and permutations of this theme. It therefore can be said that if an auxiliary system were to block the release direction of the detent lever or any member or combination of members kinematically coupled to the detent, the door latch system inertia performance could be greatly enhanced. Moreover, if the auxiliary system were to block the release direction of the detent lever and effectively decouple the release members from the detent lever, the door latch system inertia performance could be greatly enhanced and the overall crashworthiness of the vehicle could be greatly improved by negating the effect of sheet metal or linkage activation of the release mechanism.
As shown in
Referring now to
Still further and referring to
In order to translate the blocking member 18 between positions A and B an integral, internal threaded portion 22 is provided. The internal threaded portion 22 is configured to interface and be driven by a power screw member 23 which allows the blocking element 18 to be selectively driven to a desired position by rotating the power screw member 23. In one non-limiting embodiment, the power screw member 23 has an integral helical gear 24 configured to interface with a worm gear 25, that is mechanically coupled to an electric motor 26. Accordingly, selective rotation of the motor would cause the subsequent translation of the blocking element into the desired positions.
While the systems shown in
For example, and referring to the forkbolt and detent lever geometry as described previously in
In an alternative embodiment, the detent release lever 6 is clutched to the detent blocking member 7 such that movement of the detent blocking member 7 also decouples the detent release lever 6 from the release mechanism.
To this point, it has been assumed that the electric motor will receive energy via a controller to engage or disengage the blocking member. If however, the blocking member is engaged and an event occurs that severs power to the controller or to the vehicle door latch, a passenger will not be able to open the door under any normal circumstance. Therefore and in one exemplary embodiment, a manual over ride system, or energy back up system, is provided in the event of such an occurrence.
When considering a manual over ride mechanism for a detent lever blocking/release mechanism decoupling device, an issue of relevance occurs. If a passenger or inadvertent release activation were able to disengage the blocking member, it would defeat the purpose of this invention which is to greatly enhance the inertial and crashworthiness performance of the vehicle. However, when subjected to the stresses of a crash event, a human is less likely to process the required steps to reveal an auxiliary release mechanism and instead defaults to the existing release handle. Therefore, an override mechanism somehow co joined to the conventional release mechanism is desirable. However, in a crash or rollover event there may be several inertia impulses or linkage activation events capable of releasing the door latch mechanism that could override the blocking member if the override mechanism were co joined to the conventional release chain of the door latch.
Accordingly and in one exemplary embodiment, a feature of this manual over ride methodology requires multiple release motions to return the blocking member to its disengaged position and allow egress from the vehicle.
In one non-limiting embodiment, the release motions must be consecutive. For example, the design illustrated in
For example, and referring to the motor/worm gear/helical gear arrangement as previously depicted in
In the event of an engaged detent blocking member 7, the force of the release mechanism input would provide no work or movement to the detent.
Referring now to
Thus, if the release link 38 and its associated interface feature 41 are translated in the direction of arrow 40 to the release position (
Accordingly and upon returning the release link 38 back to its home position illustrated by the dashed lines in
Once the helical gear 15 is in the disengaged position, translation of the release link 38 in the direction of arrow 40 would transfer work energy to the detent, thus releasing the door, this being considered one of the three aforementioned release motions. Accordingly, the system illustrated in
Referring now to
Moreover and as illustrated, integral cam driving feature 12 is received within the linear cam slot 10 of the sliding rack 11 thus the first release motion of the release link 38 moves the dwell portion 47 to the position 48 and no work or movement is applied to the blocking member. However and upon a second release motion of the release link, the dwell portion 47 is moved from position 48 to position 49 and the blocking member is now driven to its disengaged position illustrated by reference numeral 50. Then a subsequent third release motion of the release link would release the detent lever from its latched position.
Accordingly, the system illustrated in
In an alternative embodiment, a two release motion event to fully release the latch from a vehicle body when a detent blocking member or detent is in a blocking position is provided. For example and in one embodiment, gear 15 may be configured with only a single cog 42 such that a single movement of the manual release mechanism (e.g., translation of release link 38) will move the blocking member to its disengaged position such that a subsequent movement of the manual release mechanism (e.g., translation of release link 38 again after it returns to its original position) will cause the initial blocking system or block out assembly to be in an unblocking position such that a second release motion will transfer the work energy to the detent and open the latch.
Another alternative exemplary embodiment and configuration is illustrated in
In
In view of the above alternative embodiments, the attached claims are not intended to be limited to the specific configurations illustrated in the attached drawings unless a specific literal reference to components of the specific configurations illustrated in the attached drawings appears in the claim.
As used herein, the terms “first,” “second,” and the like, herein do not denote any order, quantity, or importance, but rather are used to distinguish one element from another, and the terms “a” and “an” herein do not denote a limitation of quantity, but rather denote the presence of at least one of the referenced item. In addition, it is noted that the terms “bottom” and “top” are used herein, unless otherwise noted, merely for convenience of description, and are not limited to any one position or spatial orientation.
The modifier “about” used in connection with a quantity is inclusive of the stated value and has the meaning dictated by the context (e.g., includes the degree of error associated with measurement of the particular quantity).
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 appended claims.
This application is a divisional application of U.S. patent application Ser. No. 13/549,389 filed on Jul. 13, 2012, which claims the benefit of U.S. Provisional Patent Application No. 61/507,803 filed Jul. 14, 2011, the entire contents each of which are incorporated herein by reference thereto.
Number | Date | Country | |
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61507803 | Jul 2011 | US |
Number | Date | Country | |
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Parent | 13549389 | Jul 2012 | US |
Child | 14938668 | US |