Release lever counterweight

A counterweighted release lever for a vehicle seat back release mechanism is described. The release lever includes a counterweight providing sufficient weight to move a center of mass of the release lever towards a release lever pivot point disposed adjacent to the counterweight. The counterweight may be integral to or attached to the release lever, or may be operatively connected to a release lever shaft. Vehicle seat back release mechanisms and vehicle seat assemblies including the counterweighted release lever as described above are described.

TECHNICAL FIELD

This disclosure relates generally to seats for motor vehicles. More particularly, the disclosure relates to a counterweighted vehicle seatback latching mechanism.

BACKGROUND

In certain vehicle seating applications, many seat functions require release of the vehicle seat back latch (recliner). One way this is accomplished is to provide a long release lever operationally connected to a variety of cables, with each cable associated with a particular seat function or method of release. As non-limiting examples, particular cables may be individually associated with a vehicle seat back manual release, power-actuated release, easy passenger entry function, and others.

During a dynamic event such as a collision, a combination of lever orientation with respect to a direction of impact and lever center of gravity can cause the seat back latch/recliner to actuate. That is, typically the center of mass100of a seat back recliner lever102is distanced from the lever pivot104(seeFIG. 1A), and so on receipt of a suitable collision impact the lever tends to be displaced in a direction (arrow A) which may actuate the seat back latch/recliner. This inadvertent seat back actuation can create an unsafe situation.

Conventionally, this problem is addressed by including a return spring mechanism to overcome the inertial force of such dynamic events. With reference toFIG. 1B, a seat back recliner lever102is shown disposed on a portion of a seat back frame106. The lever102is operationally associated with various cables107for actuating various seat functions as described above (seat back manual release, power-actuated release, easy passenger entry function, and others). In such prior art mechanisms, a return spring mechanism108is provided to overcome the tendency of the release lever102to displace on impact as described above. In this mechanism, a return spring110is disposed to counteract the effects of inertia on the release lever102encountered during certain impact events.

However, such return spring mechanisms108include attendant disadvantages. Because the spring110is continuously counteracting the motion of the release lever102during a seat back112releasing action, the effort required of a user or of an automated mechanism for releasing the seat back112is increased. Spring placement is an issue, as the spring110must be placed appropriately to provide the desired counteracting function without interfering with other seat mechanisms. Still more, multiple components are required to provide such a return spring mechanism108, including the spring110, a seat-mounted bracket114for engaging an end of the spring, a release lever tab116for engaging an opposed end of the spring, optionally a sleeve118for preventing damage to seat materials caused by the spring, and others. Such mechanisms are relatively complex and add to the cost and complexity of manufacture of the various involved components and so of the seat mechanism itself.

To solve the foregoing and other problems, the present disclosure provides a counterweighted seat back release mechanism. Advantageously, the described counterweight replaces the conventional return spring mechanism described above, providing the desired inertia-countering function with a less complex and so more robust and less costly mechanism.

SUMMARY

In accordance with the purposes and benefits described herein, in one aspect of the present disclosure a counterweighted release lever for a vehicle seat back release mechanism is described. The release lever includes a counterweight providing sufficient weight to move a center of mass of the release lever towards a release lever pivot point disposed adjacent to the counterweight.

In embodiments, the counterweight is formed as a portion of the release lever and disposed adjacent to the release lever pivot point. In embodiments the counterweight comprises a bracket portion configured for attaching to a portion of the release lever disposed adjacent to the release lever pivot point. In embodiments the counterweight is attached to a latch release shaft that is operatively connected to the release lever at the release lever pivot point. The counterweight may be fabricated of a material selected from the group consisting of a powdered or sintered metal, a plastic or other polymer, a plastic-overmolded metal, a metal die casting, and a metal stamping.

In other aspects, vehicle seat back release mechanisms and vehicle seat assemblies comprising the counterweighted release lever as described above are provided.

In the following description, there are shown and described embodiments of the disclosed counterweighted seat back release mechanism. As it should be realized, the device is capable of other, different embodiments and its several details are capable of modification in various, obvious aspects all without departing from the devices and methods as set forth and described in the following claims. Accordingly, the drawings and descriptions should be regarded as illustrative in nature and not as restrictive.

Reference will now be made in detail to embodiments of the disclosed counterweighted seat back release mechanism, examples of which are illustrated in the accompanying drawing figures.

DETAILED DESCRIPTION

With reference toFIG. 2there is shown an embodiment of a counterweighted seat back release mechanism200according to the present disclosure. As depicted, the release mechanism200is disposed outboard of a seat back recliner assembly (not shown). The release mechanism200includes a release lever202, substantially similar in configuration to the prior art release lever described above and operationally connected to various cables107as described above for actuating seat functions.

In the depicted embodiment, a counterweight204is disposed substantially at a pivot point108of the release lever202. As will be appreciated, the described counterweight204replaces the function of the above-described return spring, having sufficient weight to provide a biasing force (arrow B) to the release lever202sufficient to overcome the inertia effects of the release lever, i.e. to decrease the moment arm of the lever.

As depicted, the counterweight204is defined by a bracket portion206and a head portion208. In the depicted embodiment, the head portion208includes an offset portion210comprising a sufficient amount of the weight of the counterweight204to move the center of mass of the lever202towards the lever pivot point108and decrease the moment arm of the lever. As will be appreciated, providing the weight of the counterweight204including the offset portion210as described provides the desired counteracting effect (arrow B) of the counterweight against the lever-actuating inertial force of an impact (arrow A). This occurs because the weight of the counterweight204is sufficient to move the lever202center of mass towards the lever pivot point108. It will be appreciated that the offset portion210is provided primarily for convenience, i.e. to reduce the vertical “footprint” of the counterweight while still providing the needed biasing force as described above.

FIG. 3shows an alternative embodiment of a counterweighted seat back release mechanism300according to the present disclosure. As shown, the release mechanism300is disposed outboard of a seat back recliner assembly302, which in the depicted embodiment includes a torsion spring304for assisting in folding the seat back112towards a flat configuration. A counterweight306is provided, attached to a latch release shaft308by a bracket portion310, which latch release shaft in turn is operatively attached to the release lever202. Again, as shown the counterweight306is configured such that a sufficient portion of the weight of the counterweight is positioned to one side of the counterweight at an offset portion312to move the vehicle seat back release lever's (not shown in this view) center of mass towards the lever pivot point108. Thus, the counterweight306applies a biasing force (arrow C) to the release lever202by the counterweight's biasing force imposed on the spindle308. The biasing force is sufficient to overcome the inertia effects of the release lever202.

As will be appreciated, the counterweights204,306should comprise sufficient weight to move the vehicle seat back release lever's respective centers of mass towards the lever pivot point108and in a direction opposite the inertial force of an impact tending to actuate the seat back release mechanisms.

A variety of materials are contemplated for fabricating the described counterweights204,306, including without intending any limitation powdered or sintered metal, plastic, plastic-overmolded metal, metal stamping, die casting, and others.

Obvious modifications and variations are possible in light of the above teachings. For example, as depicted the described counterweights204,306are configured for attaching to a portion of a vehicle seat back release mechanism. However, as will be readily appreciated the counterweights could be integrally formed as part of the release mechanism, for example as an integral portion of a release lever400as shown inFIG. 4. As depicted, the release lever400includes a lever arm402including a counterweight404provided as an integral element of the lever arm, and disposed substantially at a pivot point108of the lever arm. As described above, the counterweight404includes an offset portion406comprising a sufficient portion of the weight of the counterweight404to move the move the vehicle seat back release lever400's center of mass towards the lever pivot point108.

All such modifications and variations are within the scope of the appended claims when interpreted in accordance with the breadth to which they are fairly, legally and equitably entitled.