Vehicle door latch with release linkage bypass device

#The present invention generally relates to a door latch system for motor vehicles, and specifically to a door latch that does not release if the exterior door handle is moved open at a high speed.

#Various types of vehicle door latches and handles have been developed. The latch and handle assembly may include a handle that can be pulled outwardly by a user to release a door latch, thereby permitting the door to open. However, if a vehicle is subject to lateral acceleration due to a side impact such as a crash, the acceleration may cause the handle to shift outwardly due to its own mass, thereby causing the latch to release. Various counterweights and inertia locks have been developed to prevent inadvertent unlatching of a door latch during lateral acceleration of the vehicle.

#One aspect of the present invention is a latch system for vehicle doors including a movable door handle and a door latch mechanism having latched and unlatched configurations. A first linkage is connected to the door handle such that movement of the door handle moves the first linkage. A second linkage is connected to the door latch mechanism such that movement of the second linkage causes the latch mechanism to shift from the latched configuration to the unlatched configuration. The latch system further includes a bypass mechanism having an engaged configuration in which the bypass mechanism interconnects the first and second linkages such that movement of the first linkage causes movement of the second linkage to thereby unlatch the latch mechanism. The bypass mechanism disconnects the first and second linkages when the bypass mechanism is in a bypassed configuration such that movement of the first linkage does not cause movement of the second linkage to unlatch the latch mechanism. The bypass mechanism further defines a home configuration. When the bypass mechanism is in its home configuration, movement of the first linkage at a first velocity relative to the second linkage causes the bypass mechanism to shift from its home configuration to its engaged configuration. When the bypass mechanism is in its home configuration, movement of the first linkage relative to the second linkage at a second velocity that is significantly greater than the first velocity causes the bypass mechanism to shift from its home configuration to its bypass configuration such that movement of the first linkage at the second velocity does not unlatch the latch mechanism. The bypass mechanism includes a locking member that is connected to a selected one of the first and second linkages. The locking member includes a first engagement surface and a retaining surface. The bypass mechanism further includes a lever support that is connected to the other of the first and second linkages. The bypass mechanism still further includes a lever that is movably connected to the lever support. The lever includes a second engagement surface that is configured to engage the first engagement surface, whereby the lever interconnects the lever support and the locking member when the bypass mechanism is in its engaged configuration. The lever engages the retaining surface when the bypass mechanism is in its home configuration to prevent the second engagement surface from engaging the first engagement surface. The lever support is disconnected from the locking member when the bypass mechanism is in its bypassed configuration.

#In the drawings:

#FIG. 1 is a partially fragmentary schematic side elevational view of a vehicle door including a latch system having a bypass device according to one aspect of the present invention;

#FIG. 2 is a partially fragmentary schematic top plan view of the vehicle door handle and latch system of FIG. 2;

#For purposes of description herein, the terms “upper,” “lower,” “right,” “left,” “rear,” “front,” “vertical,” “horizontal,” and derivatives thereof shall relate to the invention as oriented in FIG. 1. However, it is to be understood that the invention may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions and other physical characteristics relating to the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.

#With reference to FIG. 1, a motor vehicle 1 includes one or more doors 2 that are movably mounted to a vehicle structure 6 by one or more hinges 4A, 4B. A movable exterior door handle 8 is connected to a latch mechanism 14 by first and second linkages such as cables 10 and 12 and a bypass mechanism 20 that selectively interconnects cables 10 and 12. Latch mechanism 14 engages a striker 16 when the latch mechanism 14 is in a latched state or configuration to thereby selectively retain the door 2 in a closed position. Latch mechanism 14 and striker 16 may comprise a conventional latch mechanism and striker of a type that is well known in the art. As discussed in more detail below, when exterior door handle 8 is moved outwardly by a user, the bypass mechanism 20 mechanically interconnects the cables 10 and 12 such that movement of the exterior door handle 8 by a user unlatches the latch mechanism 14 so it is no longer latched to striker 16, thereby permitting the door 2 to open (provided the latch mechanism 14 is not in a locked configuration). However, in the event of a vehicle crash/side impact resulting in rapid outward movement of exterior door handle 8, the bypass mechanism 20 will mechanically disconnect first and second cables 12 such that the rapid movement of exterior door handle 8 does not unlatch the latch mechanism 14.

#With reference to FIG. 2, handle 8 may comprise a strap type handle of a known design having a body portion 18 defining a forward end 22 having a connecting structure 24 that rotatably engages a hinge pin or pivot 26 whereby the handle 8 rotates outwardly as shown by the arrow “A” about a vertical axis 28 relative to the door 2 to a released position shown in dashed lines 8A. A spring such as torsion spring 25 biases the handle member 8 towards a closed position such that the handle 8 returns to the closed position after the handle 8 is released by a user. A rear end portion 30 of handle 8 is connected to an inner strand 32 of first cable 10, such that outward movement of rear end portion 30 to the released position 30A shifts strand 32 lengthwise. A first end of an outer sheath 34 of cable 10 is connected to a fitting 36 that is secured to the door 2, and an opposite end of outer sheath 34 of cable 10 is connected to housing 42 of bypass mechanism 20 by a fitting 58 of a known type. Cable 12 may comprise an inner strand 38 and an outer sheath 40. A first end of the outer sheath 40 is connected to housing 42 of bypass mechanism 20 utilizing a fitting 76 (FIG. 3) of a known type, and the other end of outer sheath 40 is be connected to latch mechanism 14 utilizing a fitting 36 of a known type. The bypass mechanism 20 may be utilized in connection with a strap type exterior door handle 8 as shown in FIG. 2, or the bypass mechanism 20 may be utilized in connection with other types of moveable exterior door handles that are known in the art.