Vehicle door latch mechanism

A latch assembly includes a door latch member and a release member. The door latch member pivots between a latched position and an unlatched position. The release member is movably coupled to the door latch member to move the door latch member from the latched position to the unlatched position. An inertia activated lock-out mechanism includes a locking member and a counterweight. The locking member moves between a locking position that prevents movement of the door latch member from the latched position to the unlatched position, and a non-interfering position in which the door latch member operates between the latched position and the unlatched position. The counterweight moves the locking member to the locking position in response to an inertial force exceeding a threshold level being applied to the vehicle door latch mechanism.

BACKGROUND

1. Field of the Invention

The present invention generally relates to a vehicle door latch mechanism. More specifically, the present invention relates to a vehicle door latch mechanism that includes an inertia activated lock-out mechanism that is located on the door latch mechanism that prevents movement of the vehicle door latch mechanism from a latched position in response to an impact event.

2. Background Information

The door of a vehicle typically includes a handle release mechanism that is connected via cable or other mechanical linkage to a door latch mechanism. The door latch mechanism is configured to keep the door of the vehicle in a closed orientation until a passenger operates the handle release mechanism to release the door latch mechanism allowing the door of the vehicle to move to an open orientation. In recent years, handle release mechanisms have included features that prevent the handle release mechanism from operating the door latch mechanism during an impact event.

SUMMARY

One object of the invention is to provide an inertia activated lock-out mechanism directly to or on a latch mechanism for a vehicle door configured to prevent the latch mechanism from opening a door in response to inertia.

In accordance with one aspect, a vehicle door latch mechanism includes a latch assembly and an inertial activated lock-out mechanism. The latch assembly includes a fixed structure, a door latch member and a release member. The door latch member is movably supported to the fixed structure to pivot between a latched position and an unlatched position. The release member is movably supported to the fixed structure and coupled to the door latch member to move the door latch member from the latched position to the unlatched position. The release member includes a connection portion configured to be connected to a remote actuation part. The inertia activated lock-out mechanism includes a locking member and a counterweight. The locking member is movably arranged between a locking position that prevents movement of the door latch member from the latched position to the unlatched position, and a non-interfering position in which the door latch member is free to operate between the latched position and the unlatched position. The counterweight is operatively coupled to the locking member to move the locking member to the locking position in response to an inertial force exceeding a threshold level being applied to the vehicle door latch mechanism.

DETAILED DESCRIPTION OF EMBODIMENTS

Referring initially toFIGS. 1 and 2, a vehicle10is illustrated that includes a vehicle door12with a door latch mechanism14(FIG. 2) in accordance with a first embodiment.

The vehicle10includes, among other things, a vehicle body16and the vehicle door12. The vehicle body16includes many features and elements, but for the purposes of understanding the invention, only those features related to the vehicle door12and the door latch mechanism14are described below, for the sake of brevity. For instance, the side of the vehicle body16depicted inFIGS. 1 and 2, includes an A-pillar20, a B-pillar22, a C-pillar24, a roof rail26and a sill28. The A-pillar20, the B-pillar22, the roof rail26and the sill28define a front door opening30. Similarly, the B-pillar22, the C-pillar24, the roof rail26and the sill28define a rear door opening32.

The vehicle body16is assembled with, for example, a plurality of pre-shaped, molded or stamped sheet metal elements that are welded or otherwise fixedly attached to one another to define the structural features, such as, the A-pillar20, the B-pillar22, the C-pillar24, the roof rail26and the sill28. These structural features are conventional and therefore, further description is omitted for the sake of brevity.

In the embodiment depicted inFIGS. 2 and 4, the door latch mechanism14is shown as being part of the vehicle door12, which is a rear door. However, the vehicle door12(and the corresponding door latch mechanism14) can also serve as the front door of the vehicle10. In other words, the door latch mechanism14can be installed in either a front door or a rear door, or essentially any door with a latch and corresponding latch release mechanism. For the sake of brevity, description is provided for the vehicle door12being the rear door of the vehicle10, but equally applies to a vehicle front door, a sliding door, a French style door (with hinges at a rearward portion of the door) and/or clam shell doors, such as those used in vans or commercial vehicles.

The vehicle door12is pivotally supported on the B-pillar22of the vehicle body16of the vehicle10between a closed (latched) position and an open (unlatched) position in a conventional manner. Specifically, the vehicle door12is pivotally attached at its forward end to the B-pillar22of the vehicle body16by a pair of hinges (not shown). The rearward end of the vehicle door12includes parts of the door latch mechanism14for latching the vehicle door12to the C-pillar24of the vehicle body16in a releasable manner.

As explained in greater detail below, the door latch mechanism14is provided with an inertia activated lock-out mechanism34(FIG. 3) for preventing the vehicle door12from inadvertently moving from the closed (latched) position to the open (unlatched) position in response to an impact event. Basically, as explained below, the inertia activated lock-out mechanism34is designed to respond to rapid changes in inertia during an impact event to prevent the vehicle door12from inadvertently unlatching from the C-pillar24of the vehicle body16.

Since the focus of the present disclosure is directed to the vehicle door latch mechanism14, the vehicle10and the vehicle door12will not be discussed in great detail or illustrated herein, except as they relate to the vehicle door latch mechanism14.

As best seen inFIG. 2, the vehicle door12basically includes an outer door panel36, an inner door panel38and the door latch mechanism14. These components of the vehicle door12also constitute part of the vehicle door latch mechanism14of the illustrated embodiment, as described further below. The outer and inner door panels36and38are typically sheet metal members that are stamped and fixedly secured together by a suitable fastening technique such as welding, adhesive, fasteners, etc. Basically, the outer and inner door panels36and38define the hollow interior for housing the door latch mechanism14as well as other various door elements and/or mechanisms that are well known in the art.

As shown inFIG. 3, the door latch mechanism14basically includes a latch assembly40, an inside door release handle42, an outside door release handle44, a striker46(shown inFIG. 6), and the inertia activated lock-out mechanism34. The latch assembly40of the door latch mechanism14is bolted in position within the vehicle door12along a rear section of the vehicle door12, as indicated inFIG. 5. The door latch mechanism14is operated by the inside door release handle42and the outside door release handle44in a conventional manner.

The inside door release handle42is fixedly attached to the inner door panel38in a conventional manner, such as removable fasteners or the like. Similarly, the outside door release handle44is fixedly attached to the outer door panel36in a conventional manner, such as removable fasteners or the like. The inside door release handle42and the outside door release handle44are conventional components and therefore further description is omitted for the sake of brevity, since their respective structures and operation are well known in the art.

As shown inFIG. 6, the striker46is bolted to the C-pillar24in a conventional manner.

As shown inFIGS. 8-11, the latch assembly40includes a plurality of elements, such as, for example, a housing48, a door latch member50(FIGS. 5, 10 and 11), a latch retaining member52(FIGS. 10 and 11), a release member54, a slave member56(FIGS. 10 and 11), and a link58(FIGS. 10 and 11).

The housing48is bolted to one or both of the outer and inner door panels36and38, as indicated inFIG. 5. Hence, the housing48, the outer and inner door panels36and38constitute a fixed structure that the latch mechanism40is rigidly attached to in a conventional manner.

As shown inFIGS. 7, 8 and 9, the housing48covers and protects at least a portion of the inertia activated lock-out mechanism34. InFIGS. 10 and 11, an upper portion of a cover of the housing48is removed to reveal various internal elements of the latch assembly40, including the door latch member50and the latch retaining member52. A lower portion of the cover of the housing48is removed inFIGS. 12-14to reveal elements of the inertia activated lock-out mechanism34, as described in greater detail below.

The door latch member50is movably supported to the fixed structure (the housing48) to pivot between a latched position (FIG. 10) and an unlatched position (FIG. 11). In the latched position, the door latch member50is pivoted in a clockwise direction, relative to the depicted view, about its pivot axis so as to surround and clamp onto the striker46in a conventional manner, as shown inFIG. 10. In the unlatched position, the door latch member50pivots about its pivot axis in a counterclockwise direction relative toFIG. 10, so that the striker46is released and the door12opens in a conventional manner, as shown inFIGS. 5 and 11.

The door latch member50is further biased to move toward the unlatched position by a spring (not shown) that biases the door latch member50in a conventional manner. The latch retaining member52is a remote actuation part that is supported to the housing48(the fixed structure) for pivotal movement about a shaft S1, as shown inFIGS. 10 and 11. The latch retaining member52is biased toward the position shown inFIG. 10, where the latch retaining member52retains the door latch member50in the latched position.

As shown inFIGS. 10 and 11, the release member54is preferably made of a hardened metallic material. The release member54is movably supported to the housing48(the fixed structure) and coupled to the door latch member50to move the door latch member50from the latched position to the unlatched position. More specifically, release member54pivots on a shaft S2supported on the housing48. The slave member56is fixed to the shaft S2such that the slave member56and the release member54rotate as a single body on the shaft S2. In the embodiment depicted inFIGS. 10 and 11, the slave member56is located behind the release member54. However, the exact location of the slave member56can be varied depending upon the latch design and door configuration and is not limited to the depicted arrangement.

The link58has a first end and a second end. The first end of the link58is connected for pivotal movement to the slave member56. The second end of the link58is connected for pivotal movement to the latch retaining member52. Consequently, when the release member54is moved from the latched position (FIG. 10) to the unlatched position (FIG. 11), the slave member56pulls on the link58, which pulls on the latch retaining member52. This movement in turn causes the latch retaining member52to pivot about the shaft S1, releasing the spring biased door latch member50so that the vehicle door12can open. The slave member56and the link58essentially constitute a connection portion between the release member54and the door latch member50. Hence, the release member54includes a connection portion defined by the slave member56and the link58connected to the latch retaining member52(the remote actuation part).

As is shown inFIGS. 12 and 13, the release member54includes a first end60and a second end62. The first end60is fixed to the shaft S2for rotation therewith (and for rotating the slave member56). The second end62is connected to a cable C that is coupled to one or both of the inside door release handle42and the outside door release handle44. Hence when either of the inside door release handle42or the outside door release handle44is operated, the cable C pulls on the release member54, and the release member54pivots to move the door latch member50from the latched position (FIG. 10) to the unlatched position (FIG. 11). The first end60of the release member54also includes a plurality of claw teeth64. In the depicted embodiment, there are basically three claw teeth64, as described in greater detail below with a description of the inertia activated lock-out mechanism34.

A description of the inertia activated lock-out mechanism34is now provided with specific reference toFIGS. 12-14. The inertia activated lock-out mechanism basically includes the release member54, a locking member70, a biasing member72, a base member74, a counterweight76and a tether T. The locking member70is mounted on a shaft S3for pivotal movement. Specifically, the locking member70can pivot between a locking position (FIG. 13) that prevents movement of the door latch member50from the latched position to the unlatched position, and a non-interfering position (FIGS. 12 and 14) in which the door latch member50is free to operate between the latched position and the unlatched position.

The locking member70is basically a metallic lever mounted on a shaft S3for pivoting movement about the shaft S3. The shaft S3and the shaft S2and the axes they define are parallel to one another. The locking member70is preferably made of a hardened metallic material. The locking member70includes a first end that has claw teeth78and a tether end80. The locking member70is biased toward the non-interfering position shown inFIGS. 12 and 14by the biasing member72. The biasing member72is a coil spring that is compressed before installation in the depicted embodiment. Further, the biasing member72is tuned to cooperate with the counter weight76, as described below. The biasing member72is a coil spring in the depicted embodiment, but can alternatively be a leaf spring or other type of biasing member so long as the biasing member72biases the locking member70toward the non-interfering position. In other words, the biasing member72is not limited to a coil spring.

As is shown inFIG. 14, the biasing member72being a coil spring, defines a hollow central interior with the tether T extending through the hollow central interior of the biasing member72(the coil spring).

The claw teeth78are dimensioned, sized and positioned such that they can be moved into direct contact with the claw teeth64of the release member54. As shown inFIG. 14, surfaces64a,64band64cof the claw teeth64of the release member54extend along respective planes that coincide with the shaft S2. This relationship is demonstrated by lines L1, L2and L3which extend through a pivot axis defined by the shaft S2and align with each of the surfaces64a,64band64cof the claw teeth64. Each of the lines L1, L2and L3represents a separate plane that coincides with the pivot axis of the release member54. Surfaces78a,78band78care shaped and oriented to mate with the surfaces64a,64band64c. Each of the surfaces78a,78band78cof the claw teeth78extend along planes (not shown) that extend normal to circles (not shown) centered about the shaft S3. For example, as indicated inFIG. 13, when the locking member70is moved to the locking position, the profiles of the claw teeth64of the release member54match the profiles of the claw teeth78of the locking member70. Any further force applied to either the release member54and/or to the locking member70draw the claw teeth78(and the locking member70) into closer engagement with the claw teeth64and the release member54. Hence, with the locking member70in the locking position (FIG. 13), movement of the release member54to the unlatched position (FIG. 11) is prevented. With the locking member70moved to the locking position shown inFIG. 13, the claw teeth64of the release member54engage the claw teeth of the locking member70and movement of the release member54is prevented. Since the locking member70and the release member54are made of a hardened metallic material, the locking member70and the release member54can remain structurally sound even in response to severe impact. Hence the door12can be prevented from opening during a sudden impact event, as is further described below.

The base member74includes an upper end74athat extends through an aperture in the housing48. Hence, the upper end74aof the base member74is fixedly attached to the housing48. However, as will be understood from the following description, the base member74(and the counterweight76) can be positioned at any of a variety of locations beside, below or above the housing48, so long as the counterweight76is operatively coupled to the locking member70in a manner consistent with the description provided below. As is shown inFIG. 13, when the locking member70is moved to the locking position, one end of the locking member70can contact the upper end74a. Hence, the upper end74aof the base member74is configured to limit overall movement of the locking member70defining a hard stop for the locking member70. When the locking member70moves to the locking position, the biasing member72is compressed about the upper end74aof the base member74. The upper end74ais dimensioned to receive the biasing member72during compression thereof. The limiting of movement of the locking member70serves to protect the biasing member72from being over-compressed.

The base member74includes a surface82, a bore84that extends completely through the base member74from the surface82to a distal end thereof adjacent to the biasing member72. The tether T extends through the bore84from the surface82to the distal end thereof and through the biasing member72, as described in greater detail below.

The surface82is basically a concave depression having a semi-spherical shaped surface, as indicated inFIG. 14. A portion of the counterweight76(described below) together with the surface82form a ball and socket relationship such that the counterweight76can swivel relative to the surface82, as described further below.

As best shown inFIG. 14in cross-section, the surface82has a spherical shape or semi-spherical shape (a sphere that has been cut with less that half of the spherical shape remaining). In other words, the surface82of the base member74is a concave surface relative to the remainder of the base member74. The bore84of the base member74is open to a central portion of the surface82. In other words, the bore84(an aperture) is centered relative to the surface82and defines a central axis A1that extends through the concave depression that defines the surface82. At least a portion of the tether T coincides with the central axis A1. The portion of the tether T that coincides with the central axis A1is perpendicular to the axes defined by the shafts S2and S3with the locking member70in the non-interfering position.

As shown inFIG. 14, the counterweight76includes mass86and a ball end88that has a ball shaped surface90. The mass86is spaced apart from the ball end88and the surface90. The ball shaped surface90of the ball end88of the counterweight76is shaped to mate with the surface82of the base member74. The ball end88of the counterweight76is installed within the concavity of the base member74that defines the surface82. The surface82and the ball shaped surface90of the counterweight76contact one another. The surface82and the ball shaped surface90can be provided with a Teflon® coating or other friction reducing coating such that the counterweight76is free to swivel, pivot and/or otherwise undergo movement relative to the base member74with the surface82and the surface90in contact with one another. However, it should also be understood that the surface82and the surface90can also be polished and/or otherwise surface treated in such a way as to reduce or eliminate friction therebetween.

As mentioned above, the tether T extends through the bore84of the base member74. One end of the tether T is attached to the tether end80of the locking member70. The other end of the tether T is attached to the ball end88of the counterweight76. As indicated inFIG. 14, the tether T can be embedded within the ball end88of the counterweight76. The tether T can be made of a woven metallic wire, a polymer fiber wire or other flexible material that is bendable, resilient and has a good tensile strength sufficient to retain the counterweight76to the locking member70for many, many years. More specifically, the tether T is made of a material that resists elongation. In other words, the tether T can bend and elastically deform in a manner consistent with wire or fiber, but is resistant to tensile elongation or deformation that results from being under tension.

The counterweight76defines a longitudinal axis A2that is aligned with the central axis A1of the base member74when the door latch member70is in the non-interfering position, as indicated inFIGS. 12 and 14. When mass86of the counterweight76is moved by rapid changes in inertia, the longitudinal axis A2can become angularly offset from the central axis A1of the base member74. When the counterweight76becomes angularly offset from the central axis A1of the base member74by an angle greater than a prescribed minimum angle relative to the central axis A1, the tether T pulls the locking member70causing the locking member70prevent movement of the release member54and consequently preventing movement of the door latch member50from the latched position (FIG. 10) to the unlatched position (FIG. 11).

The convex surface90of the counterweight76and the surface82(the concave depression) of the base member74define a ball and socket joint such that the counterweight76can undergo swiveling movement 360 degrees about the central axis A1of the base member74.

As described above, the counterweight76is operatively coupled to the locking member70via the tether T to move the locking member70to the locking position in response to an inertial force exceeding a threshold level being applied to the door latch mechanism14. More specifically, the mass86of the counterweight76, the spring constant of the biasing member72and the distance between the center of gravity of the mass86of the counterweight76and the surface82of the base member74are determined in consideration of the threshold level of inertial force necessary to move the counterweight76, pull the tether T and the locking member70, thereby preventing the latch assembly40from operating to open the door12.

In an impact event, such as a head-on collision, a side collision, or a roll-over incident, it is advantageous to at least temporarily maintain the doors12of the vehicle10in a closed position. The inertia activated lock-out mechanism34, and in particular the counterweight76, are designed to respond to impact events to prevent the latch assembly40from allowing the door12to open. Even in a minor impact event, where little or no damage is done to the vehicle10, the counterweight76of the inertia activated lock-out mechanism34moves.

If the change in inertia in any direction about the axis A1reach the level of the threshold level discussed above, the counterweight76moves and pulls on the tether T moving the locking member70to the locking position (FIG. 13). The door12is temporarily prevented from opening. Once movement of the vehicle10is such that there are no further changes in inertia acting on the counterweight76, the counterweight76is centered with the axis A2coinciding with the axis A1(FIG. 12) due to the force of the biasing member72. In other words, the biasing member72not only biases the locking member70to the non-interfering position (FIG. 12), the biasing member74also applies a force on the tether T pulling the counterweight76into alignment with the axis A1. Hence, after an impact event, the biasing force of the biasing member74restores operation of the latch assembly40to normal and the door12can now be opened.

The threshold level discussed above is dependent upon a variety of variables. For example, the force applied by the biasing member72on the locking member70and the tether T must be sufficient to restore and maintain the counterweight76in a normal, at rest position (FIG. 12) for everyday operation of the vehicle10. The weight of the mass86and the distance of the center of gravity of the mass86and the surface82are considered with respect to a moment generated relative to the surface82in response to rapid changes in inertia in the determination of the threshold level.

It is acceptable for the counterweight76to move, for instance, when the door12is opened or closed thereby moving the locking member70to the locking position, because after a second or two, the biasing member74will urge the counterweight back into the at rest position shown inFIG. 12. Thereafter, the door12can be opened and closed as desired. In other words, the inertia activated lock-out mechanism34can be highly sensitive to even slight changes in inertia without interfering with normal operation of the latch mechanism40.

Second Embodiment

The inertia activated lock-out mechanism34′ includes many of the features of the first embodiment, such as the release member54, the locking member70and the biasing member72. However, in the second embodiment, the base member74has been replaced with a base member74′; the tether T has been replaced with a tether T′; and a second counterweight176has been added.

The base member74′ includes the bore84and the surface82, as in the first embodiment, but also includes a second bore84′ that intersects the bore84, and a second concave surface182, as shown inFIG. 15. At the intersection of the bore84and the second bore84′, a roller R is provided to ensure smooth movement of the tether T′ during impact events. The concave surface182is approximately the same as the surface82, but is oriented perpendicular to the surface82. In other words, the second bore84′, which is centered relative to the surface182, is perpendicular to the bore84.

The second counterweight176includes a second mass186and a second ball end188. The second ball end188has a ball shaped surface190. The second counterweight176is approximately the same as the counterweight76and has basically the same features, except that the second counterweight176is oriented perpendicular to the counterweight76. The second counterweight176operates in a manner that is basically the same as the counterweight76, with the bore84′ and a portion of the tether T′ defining an axis A1′, and the counterweight176defining a second axis A2′. When the counterweight176is in an at rest position as shown inFIG. 15, the axis A1′ and the second axis A2′ coincide. However, in response to rapid changes in inertia, the counterweight176will move such that the second axis A2′ is angularly offset from the axis A1′ causing the counterweight176to pull on the tether T′ moving the locking member74from the non-interfering position to the locking position.

The use of both the counterweight76and the counterweight176increases the sensitivity of the inertia activated lock-out mechanism34′ as compared to the inertia activated lock-out mechanism34of the first embodiment. More specifically, rapid changes in inertia resulting from impact events from just about any possible angle relative to the vehicle10can be detected and the doors12prevented from opening until after the conclusion of the impact event.

There are various elements and components of the vehicle10that are conventional components well known in the art. Since such elements and components are well known in the art, these structures will not be discussed or illustrated in detail herein. Rather, it will be apparent to those skilled in the art from this disclosure that the components can be any type of structure and/or programming that can be used to carry out the present invention.

General Interpretation of Terms