Chairs and seats – Movable bottom – Bottom and back movable as a unit
Reexamination Certificate
1999-10-28
2001-08-14
Cranmer, Laurie K. (Department: 3624)
Chairs and seats
Movable bottom
Bottom and back movable as a unit
C297S344130, C248S419000
Reexamination Certificate
active
06273507
ABSTRACT:
BACKGROUND OF THE INVENTION
This application relates generally to a power or manual seat adjustment assembly for adjusting the height of a seat within a vehicle. More particularly, this invention relates to a vertical seat adjuster having a torque tube and linkage assembly for engaging a stop to move the seat between maximum lowered and raised positions.
Seat adjustment assemblies for adjusting seat position within a vehicle are generally well known. Most arrangements provide for a seat to be moved or adjusted in forward and rearward directions within a vehicle. In many circumstances, it is desirable to have a seat adjustment assembly that can vertically move a seat between lowered and raised positions. Such an arrangement is necessary, for example, to accommodate vehicle drivers that are of varying heights. These seat adjusters can be manually/mechanically controlled or can be electrically controlled.
Electrically controlled adjustment assemblies typically include a vertical drive mechanism that includes a motor, a spindle or threaded drive shaft, a drive nut, and a drive link connecting the shaft to a torque tube. The motor drives the nut to move the shaft, and the drive link takes the linear movement of the shaft and provides rotational input to the torque tube. A linkage assembly is used to connect the torque tube to a seat bottom, and as the torque tube rotates, the linkage assembly causes the seat bottom to move vertically.
The seat bottom travels between two extreme positions, a maximum lowered position and a maximum raised position. The total vertical distance of travel between these two positions can vary depending on design requirements. However, in order to ensure maximum operating efficiency for the vertical drive mechanism, it is preferable to have the drive shaft and the drive link at a ninety degree angle with respect to each other when the seat bottom is at a mid-adjustment position, i.e. at a distance half-way between the maximum lowered and raised positions. In order to maintain this same orientation for seats having different total vertical travel distances, the length of the drive shaft is changed. This is expensive because it causes proliferation of parts.
Sometimes, a collar or sleeve is placed on the shaft to limit vertical travel distance. This allows the same shaft to be used for seats having different total vertical travel distances. The collar or sleeve is simply positioned at a location on the drive shaft that corresponds to the maximum desired vertical travel distance. The disadvantage with this configuration is that the drive shaft and drive link are not always maintained at a ninety degree angle with respect to each other at the mid-adjusted position. Thus, it is desirable to have a vertical adjustment mechanism that can utilize a single drive shaft for seats having different total vertical travel distances that maintain a ninety degree relationship between the shaft and the drive link at the mid-adjust position.
Sometimes a nut and spring washer are mounted on the drive shaft to serve as a stop to define the maximum raised and lowered positions. One disadvantage with this configuration is that the nut over-tightens at the maximum adjusted positions. This can cause what is know as lock-up or a sticking condition, which makes it more difficult to move from the maximum adjusted position to another vertical seat position. Thus, it is desirable to have vertical adjustment mechanism that eliminates lock-up and sticking during adjustment. The mechanism should also reduce the number of required parts, improve ease of assembly, and maintain or improve the operating efficiency of the drive system.
SUMMARY OF THE INVENTION
In general terms, this invention is a vertical seat adjustment assembly utilizing an external stop limit movement of a seat bottom between a maximum lowered position and a maximum raised position. Separate adjustment assemblies can be installed at the front and rear portions of the seat for adjusting the height of the front portion independently from the rear portion. Alternatively, a single adjustment assembly can be used to adjust the height of either the front or rear portion where the adjustment assembly includes a connecting linkage assembly to correspondingly adjust the height of the other portion of the seat bottom. The adjustment assembly utilizes a link member controlled by movement of a torque tube to engage the stop.
In a preferred embodiment of this invention, the adjustment assembly for adjusting the height of a vehicle seat includes a first mount, a second mount spaced apart from the first mount, and a torque tube extending between the first and second mounts to define a pivot axis. The first and second mounts support a seat member that is movable between a lowered position and a raised position. An actuator selectively supplies rotational input to the torque tube to move the seat member. A stop is supported by one of the mounts and at least one link member receives input from the torque tube and has an engagement portion for engaging the stop to define a maximum raised position and an engagement portion for engaging the stop to define a maximum lowered position.
The adjustment assembly is preferably used in a vehicle seat with power/electrical actuators, however, manual or mechanical actuation could also be used. Preferably the adjustment assemblies is used in a seat having an inboard track assembly mounted to a vehicle structure and an outboard track assembly mounted to a vehicle structure and spaced laterally from the inboard track assembly. The inboard and outboard track assemblies each include a first track and a second track supported for longitudinal movement relative to the first track. A seat bottom is supported on the second track for movement therewith. A horizontal drive mechanism includes a first motor for controlling movement of the second track with respect to the first track. At least one torque tube extends between the inboard and outboard track assemblies and is connected to the seat bottom by a linkage assembly to move the seat bottom between a lowered position and a raised position. A vertical drive mechanism includes a second motor for controlling movement of the torque tube. The link member rotates with the torque tube to engage the stop at the maximum raised and lowered positions.
The subject invention offers several advantages over prior art adjustment systems because it provides a simplified assembly for adjusting the vertical position of a seat within a vehicle that is durable, easy to assemble, quiet in operation, and eliminates lock-up and sticking.
These and other features and advantages of the present invention will be best understood from the following specification and drawings, the following of which is a brief description.
REFERENCES:
patent: 5462337 (1995-10-01), Yamakami
patent: 5697674 (1997-12-01), Aufrere et al.
patent: 5738327 (1998-04-01), Tanaka et al.
patent: 5871195 (1999-02-01), Gauger
patent: 5924668 (1999-07-01), Garrido
patent: 6095475 (2000-08-01), Willms et al.
patent: 6145914 (2000-11-01), Downey et al.
patent: 6179265 (2001-01-01), Downey et al.
Cranmer Laurie K.
Dura Global Technologies
Porter Wright Morris & Arthur LLP
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