MEMORY LEVERS FOR LATCH MECHANISMS OF VEHICLE COMPARTMENT CLOSURE ASSEMBLIES

Abstract

Disclosed are latch mechanisms for vehicle compartment closure assemblies, methods for making or using such latch mechanisms, and motor vehicles with a latch system for sensing latching/unlatching of a closure assembly. A latch mechanism includes a forkbolt that attaches to the vehicle body and moves between a latched position, engaging a striker and thereby latching a compartment closure assembly in a closed position, and an unlatched position, disengaging the striker. A detent lever attaches to the vehicle body adjacent the forkbolt and moves between a locked position, locking the forkbolt in the latched position, and an unlocked position, disengaging the forkbolt. A memory lever adjacent the forkbolt moves between a catching position, retaining the detent lever in the unlocked position, and a releasing position, disengaging the detent lever. The forkbolt, when moving from the unlatched to the latched position, moves the memory lever from the catching to the releasing position.

Claims

1. A latch mechanism for a compartment closure assembly of a motor vehicle, the compartment closure assembly being movably mounted to a body of the motor vehicle to transition between open and closed positions, the motor vehicle including a striker attached to the vehicle body or the compartment closure assembly, the latch mechanism comprising: a forkbolt configured to attach to the motor vehicle and move between a latched position, whereat the forkbolt engages the striker and thereby latches the compartment closure assembly in the closed position, and an unlatched position, whereat the forkbolt disengages the striker such that the compartment closure assembly is movable to the open position; a detent lever configured to attach to the body adjacent the forkbolt and move between a locked position, whereat the detent lever engages and locks the forkbolt in the latched position, and an unlocked position, whereat the detent lever disengages the forkbolt; and a memory lever configured to attach to the body adjacent the forkbolt and move between a catching position, whereat the memory lever engages and catches the detent lever in the unlocked position, and a releasing position, whereat the memory lever disengages the detent lever, wherein the forkbolt, when moving from the unlatched position to the latched position, moves the memory lever from the catching position to the releasing position.

2. The latch mechanism of claim 1, wherein the memory lever includes a memory lever body with a catch shelf, and the detent lever includes a detent lever body with a detent pin projecting therefrom, the detent pin seating on the catch shelf when the memory lever is in the catching position and the detent lever is in the unlocked position.

3. The latch mechanism of claim 1, wherein the memory lever includes a memory lever body with a toe projecting therefrom, and the forkbolt includes a forkbolt lever body with a finger projecting therefrom, the finger pressing against the toe and pushing the memory lever to the releasing position when the forkbolt moves from the unlatched to the latched position.

4. The latch mechanism of claim 1, wherein the detent lever includes a detent lever body with a ramped surface, and the forkbolt includes a forkbolt body with a finger projecting therefrom, the finger pressing against the ramped surface and disengaging the detent lever from the memory lever when the forkbolt moves from the unlatched to the latched position.

5. The latch mechanism of claim 1, wherein the detent lever includes a detent lever body with a recessed cavity, and the forkbolt includes a forkbolt body with a finger projecting therefrom, the finger seating in the recessed cavity and pressing against the detent lever body when the detent lever is in the locked position and the forkbolt is in the latched position.

6. The latch mechanism of claim 1, further comprising a housing with a stop shoulder, wherein the memory lever includes a memory lever body rotatably mounted to the housing and including a stop tab projecting therefrom, the stop tab engaging the stop shoulder to thereby limit rotation of the memory lever to the catching position.

7. The latch mechanism of claim 1, wherein the forkbolt rotates about a first axis, and the detent lever rotates about a second axis substantially perpendicular to the first axis.

8. The latch mechanism of claim 7, wherein the memory lever rotates about a third axis substantially perpendicular to the first axis and substantially parallel to the second axis.

9. The latch mechanism of claim 1, wherein the motor vehicle includes an ajar switch actuable to generate an electronic signal indicating the compartment closure assembly is in the open position, and the detent lever includes a detent lever body with a cam surface, the cam surface being configured to engage and actuate the ajar switch when the detent lever is moved to the unlocked position.

10. The latch mechanism of claim 1, further comprising a first bias member biasing the detent lever to the locked position.

11. The latch mechanism of claim 1, further comprising a second bias member biasing the memory lever to the catching position.

12. The latch mechanism of claim 1, wherein the forkbolt includes a forkbolt body defining a throat configured to receive and capture therein the striker of the compartment closure assembly.

13. The latch mechanism of claim 1, further comprising a latch housing configured to mount on the body of the motor vehicle, the forkbolt, detent lever and memory lever each being rotatably mounted to the latch housing at a respective pivot position.

14. A motor vehicle comprising: a vehicle body with an interior compartment and a passenger compartment; a compartment closure assembly movably mounted to the vehicle body to transition between an open position, providing access to the interior compartment, and a closed position, obstructing access to the interior compartment; a striker attached to the vehicle body or the compartment closure assembly; a release mechanism located within the passenger compartment; and a latch mechanism, including: a latch housing mounted to the vehicle body; a forkbolt rotatably mounted to the latch housing to selectively transition between a latched position, whereat the forkbolt engages the striker and thereby latches the compartment closure assembly in the closed position, and an unlatched position, whereat the forkbolt disengages the striker such that the compartment closure assembly is movable to the open position; a detent lever rotatably mounted to the latch housing adjacent the forkbolt to transition between a locked position, whereat the detent lever engages and locks the forkbolt in the latched position, and an unlocked position, whereat the release mechanism disengages the detent lever from the forkbolt; and a memory lever rotatably mounted to the latch housing adjacent the detent lever to transition between a catching position, whereat the memory lever engages and catches the detent lever in the unlocked position, and a releasing position, whereat the memory lever disengages the detent lever, wherein the forkbolt, when moving from the unlatched position to the latched position, disengages the detent lever from the memory lever and concurrently moves the memory lever from the catching position to the releasing position.

15. A method of assembling a latch mechanism for a compartment closure assembly of a motor vehicle, the compartment closure assembly being movably mounted to a vehicle body to transition between open and closed positions, the motor vehicle including a striker attached to the vehicle body or the compartment closure assembly, the method comprising: attaching a forkbolt to the vehicle body to move between a latched position, whereat the forkbolt engages the striker and thereby latches the compartment closure assembly in the closed position, and an unlatched position, whereat the forkbolt disengages the striker such that the compartment closure assembly is movable to the open position; attaching a detent lever to the vehicle body adjacent the forkbolt to move between a locked position, whereat the detent lever engages and locks the forkbolt in the latched position, and an unlocked position, whereat the detent lever disengages the forkbolt; and attaching a memory lever to the vehicle body adjacent the forkbolt to move between a catching position, whereat the memory lever engages and catches the detent lever in the unlocked position, and a releasing position, whereat the memory lever disengages the detent lever, wherein the forkbolt, when moving from the unlatched position to the latched position, moves the memory lever from the catching position to the releasing position.

16. The method of claim 15, wherein the memory lever includes a memory lever body with a catch shelf, and the detent lever includes a detent lever body with a detent pin projecting therefrom, the detent pin seating on the catch shelf when the memory lever is in the catching position and the detent lever is in the unlocked position.

17. The method of claim 15, wherein the memory lever includes a memory lever body with a toe projecting therefrom, and the forkbolt includes a forkbolt lever body with a finger projecting therefrom, the finger pressing against the toe and pushing the memory lever to the releasing position when the forkbolt moves from the unlatched to the latched position.

18. The method of claim 15, wherein the detent lever includes a detent lever body with a ramped surface, and the forkbolt includes a forkbolt body with a finger projecting therefrom, the finger pressing against the ramped surface and disengaging the detent lever from the memory lever when the forkbolt moves from the unlatched to the latched position.

19. The method of claim 15, wherein the detent lever includes a detent lever body with a recessed cavity, and the forkbolt includes a forkbolt body with a finger projecting therefrom, the finger seating in the recessed cavity and pressing against the forkbolt body when the detent lever is in the locked position and the forkbolt is in the latched position.

20. The method of claim 15, further comprising mounting a latch housing on the vehicle body, wherein the attaching the forkbolt, the attaching the detent lever, and the attaching the memory lever each includes rotatably mounting a respective one of the forkbolt, the detent lever, and the memory lever to the latch housing at a corresponding pivot position.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] FIG. 1 is an elevated, front perspective-view illustration of a representative motor vehicle with an inset view of a representative compartment closure latch mechanism with a switch memory lever in accordance with aspects of the present disclosure.

[0012] FIGS. 2A and 2B are side-view and perspective-view illustrations, respectively, of the forkbolt, detent lever and memory lever of FIG. 1 when the representative latch mechanism is in the full-closed state.

[0013] FIGS. 3A and 3B are side-view and perspective-view illustrations, respectively, of the forkbolt, detent lever and memory lever of FIG. 1 when the representative latch mechanism is in a released state.

[0014] FIGS. 4A and 4B are side-view and perspective-view illustrations, respectively, of the forkbolt, detent lever and memory lever of FIG. 1 when the representative latch mechanism is in the full-open state.

[0015] The present disclosure is amenable to various modifications and alternative forms, and some representative embodiments have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the novel aspects of this disclosure are not limited to the particular forms illustrated in the appended drawings. Rather, the disclosure is to cover all modifications, equivalents, combinations, subcombinations, permutations, groupings, and alternatives falling within the scope of this disclosure as defined by the appended claims.

DETAILED DESCRIPTION

[0016] This disclosure is susceptible of embodiment in many different forms. There are shown in the drawings and will herein be described in detail representative embodiments of the disclosure with the understanding that these illustrated examples are provided as an exemplification of the disclosed principles, not limitations of the broad aspects of the disclosure. To that extent, elements and limitations that are described, for example, in the Abstract, Summary, and Detailed Description sections, but not explicitly set forth in the claims, should not be incorporated into the claims, singly or collectively, by implication, inference or otherwise.

[0017] For purposes of the present detailed description, unless specifically disclaimed: the singular includes the plural and vice versa; the words and and or shall be both conjunctive and disjunctive; the word all means any and all; the word any means any and all; and the words including and comprising and having mean including without limitation. Moreover, words of approximation, such as about, almost, substantially, approximately, and the like, may be used herein in the sense of at, near, or nearly at, or within 0-5% of, or within acceptable manufacturing tolerances, or any logical combination thereof, for example. Lastly, directional adjectives and adverbs, such as fore, aft, inboard, outboard, starboard, port, vertical, horizontal, upward, downward, front, back, etc., are with respect to a motor vehicle, such as a forward driving direction of a motor vehicle when the vehicle is operatively oriented on a normal driving surface, for example.

[0018] Aspects of the present disclosure provide a memory lever with an ajar switch status-retention feature that holds the detent in a lifted position when the forkbolt disengages the striker pin, which functions to reliably retain activated the ajar switch. As the forkbolt moves towards the latched position, e.g., under the force of a moving striker, the forkbolt pushes the memory lever out of engagement with the detent while driving the detent up slightly to lift it over an edge of an engagement surface of the forkbolt. The detent is thereby allowed to drop into engagement with the forkbolt; when this occurs, the ajar switch output signal changes from open to closed (e.g., switch itself changes from on (closed) to off (open)). The differential position of the detent between the just-released condition and the full-open condition helps to ensure a seamless interaction between the detent, memory lever, and fork bolt. For example, if the latch mechanism is released, but the compartment closure does not move sufficiently within the release pulse, the detent will be dropped either onto a forkbolt surface or a memory lever surface; in either case, it will be supported in a position that activates the ajar switch. If the detent drops onto the forkbolt first, as the closure is opened, it will drop further onto the retaining notch of the memory lever. Conversely, as the gate is closed, the forkbolt lifts the detent while simultaneously pushing the memory lever out of engagement with the detent. Thus, the detent is prevented from moving into an undesirable position that would give a false latch signal. In addition, the latch mechanism architecture helps to ensure that the memory lever cannot interfere with the ability of the latch to be re-engaged.

[0019] Referring now to the drawings, wherein like reference numbers refer to like features throughout the several views, there is shown in FIG. 1 a representative automobile, which is designated generally at 10 and portrayed herein for purposes of discussion as a two-seat coupe-style passenger vehicle. Mounted to the vehicle body 12, e.g., forward of a vehicle passenger compartment 14 and aft of a front bumper assembly 16, is an engine hood assembly 18 that extends across and covers the upper extent of an engine compartment 20. The illustrated automobile 10also referred to herein as motor vehicle or vehicle for shortis merely an exemplary application with which novel aspects and features of this disclosure may be practiced. In the same vein, implementation of the present concepts into a front-engine-layout hood assembly should also be appreciated as a representative application of the novel aspects and features disclosed herein. As such, it will be understood that aspects and features of this disclosure may be integrated into various types of engine and hood layouts, applied to other compartment closure assemblies, and implemented for any logically relevant type of motor vehicle. As an example, it is envisioned that the disclosed latch assemblies be integrated into multi-latch tailgate and liftgate systems of pickup trucks and sport utility vehicles. Lastly, the drawings presented herein are not necessarily to scale and are provided purely for instructional purposes. Thus, the specific and relative dimensions shown in the drawings are not to be construed as limiting.

[0020] Engine hood assembly 18 of FIG. 1 (also referred to herein as compartment closure assembly or closure assembly) is pivotally mounted to one or more load-bearing body frame members of the vehicle 10 to provide access to and securely close the top portion of the engine compartment 20. For instance, the hood assembly 18 may be pivotally mounted via a pair of dual-point hinges with pneumatic cylinder actuators to the lateral engine compartment rails (not visible in the views provided) of the vehicle body 12. The vehicle 10 is equipped with a latch and lock system that employs a concealed latch mechanism 22 to secure the engine hood assembly 18 in a closed position, as shown in FIG. 1. A latch release mechanism 24, shown located inside the passenger compartment 14, e.g., underneath the steering column or adjacent the driver seat frame, includes a lever, a button or other user interface that is pulled, pressed or otherwise activated to disengage the latch mechanism 22 such that the hood assembly 18 can be manually or automatically opened. In a mechanical system architecture, pulling on a release lever of the release mechanism 24 will apply a tensile force to a latch release cable 26. The loaded release cable 26 of the latch and lock system, which may be a Bowden-type cable, activates and thereby disengages the latch mechanism 22 at the front end of the engine hood assembly 18 opposite the hinge mount. This allows the hood assembly 18 to be moved to an open position, e.g., under the biasing force of the pneumatic cylinders. Other mounting and latching architectures, including mechanical, electrical, and electro-mechanical configurations, are envisioned as being within the scope of this disclosure. For instance, the release cable 26 may be representative of an electrical wire harness or fiber optic cable, e.g., in applications where the latch mechanism 22 is embodied as a power latch, as described in further detail below.

[0021] Presented in the inset view of FIG. 1 is an electronically actuated (power) latch mechanism 22 for regulating the opening and closing of the compartment closure assembly 18. The representative latch mechanism 22 is provided with a rigid, robust and corrosion-resistant latch housing that is generally composed of a housing cover 28, a lower housing bracket 30, housing cover plate 32, and a housing frame plate 34. Housing cover 28 is shown in FIG. 1 mechanically coupled, e.g., via self-locking pan-head bolts 36, onto the lower housing bracket 30 and housing cover plate 32. Housing cover plate 32, in turn, is mechanically coupled, e.g., via flanged hex-head nuts 38, to the housing frame plate 34, which provides functional mounting support for the entire latch mechanism 22. According to the illustrated design, for example, the latch mechanism 22 is rigidly mounted via frame plate 34, e.g., to a tie bar cross-member (not visible in the views provided) of the vehicle body 12. It may be desirable that the constituent parts of the latch housing be constructed of a strong yet lightweight material, such as thermoplastic polymers and other plastic materials, or aluminum, steel and other metals, or combinations thereof. Clearly, the shape, size and/or number of housing parts may be modified, for example, to accommodate packaging and design requirements for different vehicle platforms. In this regard, the illustrated latch mechanism 22 is purely representative and, thus, non-limiting of the inventive concepts disclosed herein.

[0022] Housing cover 28 is constructed to conceal and protect a servo motor and gear components (none of which are visible in the views provided) for selectively disengaging a forkbolt 40 from a striker 15 through cooperative operation between the forkbolt 40, a detent lever 42 and a memory lever 44, as will be described in extensive detail hereinbelow. The aforementioned motor and gear components, as well as an electronic ajar switch 46, are mechanically supported on the lower housing bracket 30. Functional support for the forkbolt 40, detent lever 42 and memory lever 44, as well as a pair of bias members 48 and 50, is provided by the housing cover plate 32. Shifting of the forkbolt 40 may be accomplished by an internal drive architecture comprised of a two-way (reversible) electric servomotor that transfers driving power through a gear train (e.g., worm gear engaging a spur gear) to synchronously rotate the detent lever 42. Operation of this motor is accomplished through electronic command signals from a vehicle controller or dedicated control module, which are generated responsive to activation of the release mechanism 24. In so doing, the detent lever 42 disengages from the forkbolt 40, allowing the forkbolt 40 to disengage from a striker pin 17 that is mounted to the hood assembly 18 via a striker plate 19.

[0023] With continuing reference to FIG. 1, it is seen that the latch mechanism housing, namely frame plate 34, is fabricated with a fish mouth opening, generally indicated as 35, for receiving the striker pin 17 when the engine hood assembly 18 is drawn closed. Forkbolt 40 is stowed within frame plate 34, pivotally mounted to the cover plate 32, e.g., via a pivot pin 52 (FIG. 2A), to selectively rotate about a first axis A1 (FIG. 3A) between a latched position (FIGS. 2A and 2B) and an unlatched position (FIGS. 4A and 4B). When in the latched position, a throat 41 (FIG. 2B) of the forkbolt 40 receives and captures the striker pin 17, thereby securing the compartment closure assembly 18 in the closed position. Detent lever 42 is pivotally mounted on the housing cover plate 32 adjacent the forkbolt 40, e.g., via a respective pivot pin 54 (FIG. 2A), to selectively rotate about a second axis A2 (FIG. 3A), which is substantially perpendicular to the first axis A1, between a locked position (FIGS. 2A and 2B) and an unlocked position (FIGS. 4A and 4B). Upon being moved to the locked position, a detent cavity 43 (FIG. 2B) of the detent lever 42 engages with a forkbolt finger 45 of the forkbolt 40 to lock the forkbolt 40 in the latched position shown in FIG. 2A. First bias member 48, which is portrayed in the drawings as a helical torsion spring, pushes the detent lever 42 towards this locked position. While the forkbolt 40 and detent lever 42 are engaged in this manner such that the latch mechanism 22 is in the full-closed state, forkbolt 40 holds the memory lever 44 in a releasing position (FIGS. 2A and 2B), disengaged from the detent lever 42.

[0024] FIGS. 4A and 4B illustrate the forkbolt 40, detent lever 42 and memory lever 44 when the latch mechanism 22 is in a full-open state. In particular, the detent lever 42 is rotated, e.g., in a counterclockwise direction in FIG. 3A, to an unlocked position in which the detent lever 42 is lifted away and disengaged from and the forkbolt 40. Detent lever 42 is moved to this unlocked/disengaged position by a detent crank 56, the rotation of which is controlled through operation of the latch mechanism 22 motor and gear train described above. This will permit the forkbolt 40 to be rotated, e.g., in a counterclockwise direction in FIG. 3B, to the unlatched position of FIG. 4B. A third bias member 60, which is also portrayed as a helical torsion spring in FIG. 1, pushes the forkbolt 40 towards this unlatched position. In so doing, the forkbolt throat 41 releases or otherwise disengages from the striker 15 such that the closure assembly 18 is movable to the open position. Memory lever 44 is pivotally mounted to the housing cover plate 32, e.g., via a dedicated pivot pin 58 (FIG. 2A), adjacent the forkbolt 40 and detent lever 42 to selectively rotate about a third axis A3 (FIG. 3A) between a releasing position (FIGS. 2A and 2B) and a catching position (FIGS. 4A and 4B). As seen in FIG. 3A, the axis A3 of the memory lever 44 is substantially perpendicular to the axis Al of the forkbolt 40 and substantially parallel to the axis A2 of the detent lever 42. When moved to the catching position, e.g., in a clockwise direction in FIG. 3A, this memory lever 44 engages and catches the detent lever 42 in the unlocked position. This, in turn, helps to ensure that the ajar switch 46 remains activated and, thus, continuously outputs electronic signals indicating the engine hood assembly 18 is open. Second bias member 50, which is depicted as a helical torsion spring in FIG. 1, pushes the memory lever 44 to the catching position shown in FIGS. 4A and 4B.

[0025] According to the illustrated architecture, the forkbolt 40 is fabricated with a single-piece, J-shaped forkbolt body 51 (FIG. 2B) that is integrally formed with an elongated stem 53 and a hooked descender 55 that projects generally transversely from a proximal end of the stem 53. Forkbolt finger 45 projects in a longitudinal direction from a distal end of the stem 53, whereas the curved section of the hooked descender 55 defines the throat 41. Likewise, the detent lever 42 is fabricated with a single-piece, L-shaped detent body 57 (FIG. 2A) that is integrally formed with an elongated stem 59 and a leg 61 that projects generally orthogonally from a proximal end of the stem 59. Overmolded on a distal end of the stem 59 is a cam surface 49, whereas the leg 61 defines the detent cavity 43 and is formed or machined with a ramped surface 63. An elongated, cylindrical detent pin 62 is integrally formed with, and projects orthogonally from, a distal end of the leg 61 proximal the detent cavity 43 (FIG. 2B). The memory lever 44 is fabricated with a single-piece, C-shaped memory lever body 65 that is integrally formed with a central stress section 67 and a leg section 69 that cooperatively define a catch shelf 71. An elongated stop tab 73 is integrally formed with, and projects radially outward from, a circular arm section 75 of the memory lever body 65. In the same vein, a triangular toe 77 projects from a distal end of the leg section 69.

[0026] During operation of the latch mechanism 22, cam surface 49 rotates with the detent body 57 around axis A2 to slidably engage with and actuate the ajar switch 46 as the detent lever 42 is moved from the locked to the unlocked position (e.g., from FIG. 2A, through FIG. 3A, to FIG. 4A). As the detent lever 42 transitions to this unlocked position, forkbolt finger 45 unseats from the detent cavity 43, and the detent leg 61 concurrently rotates away from the forkbolt 40. When the detent body 57 is sufficiently rotated such that the ramped surface 63 clears the forkbolt body 51, thus allowing the forkbolt 40 to complete its rotation to the unlatched position, detent pin 62 seats on the catch shelf 71 of the memory lever 44, which is concomitantly rotating to the catching position. During transition of the latch mechanism 22 to the full-open state, rotation of the memory lever 44 may be limited to the catching position by the stop tab 73 engaging a stop shoulder 79 of the latch housing, as best seen in FIG. 4A.

[0027] Conversely, when the forkbolt 40 rotates from the unlatched to the latched position during transition of the latch mechanism 22 to the full-closed state (e.g., from FIG. 4B, through FIG. 3B, to FIG. 2B), the forkbolt finger 45 slidably presses against the detent's ramped surface 63, as best seen in FIG. 3B. This causes the detent body 57 to rotate, e.g., in a counterclockwise direction in FIG. 3A, whereby the detent pin 62 is lifted off of the catch shelf 71 and the detent lever 42 is operatively disengaged from the memory lever 44. At the same time, forkbolt 40 shifts the memory lever 44 away from the detent lever 42, rotating the memory lever body 65, e.g., in a counterclockwise direction in FIG. 3A, from the catching position of FIG. 4A to the releasing position of FIG. 2A. In particular, as forkbolt finger 45 presses against the ramped surface 63, the finger 45 also pushes against the triangular toe 77 until the memory lever 44 reaches the releasing position. Once the forkbolt finger 45 clears the detent's ramped surface 63, the detent lever 42 rotates, e.g., in a clockwise direction in FIG. 3A, such that the finger 45 seats within the recessed cavity 43 and presses against the detent body 57. In so doing, the detent lever 42 is retained in the locked position and the forkbolt 40 is retained in the latched position of FIGS. 2A and 2B.

[0028] Aspects of the present disclosure have been described in detail with reference to the illustrated embodiments; those skilled in the art will recognize, however, that many modifications may be made thereto without departing from the scope of the present disclosure. The present disclosure is not limited to the precise construction and compositions disclosed herein; any and all modifications, changes, and variations apparent from the foregoing descriptions are within the scope of the disclosure as defined by the appended claims. Moreover, the present concepts expressly include any and all combinations and subcombinations of the preceding elements and features.