Supports – Stand – Adjustable vertically
Reexamination Certificate
1999-02-04
2001-06-05
Braun, Leslie A. (Department: 3632)
Supports
Stand
Adjustable vertically
C248S631000, C267S131000, C267S064240
Reexamination Certificate
active
06241209
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to seat supports or suspension systems for vehicle seats.
Numerous vehicle seat suspensions are known, including those having air bag or air spring suspensions for resiliently supporting a seat in a selected position. In such suspension systems, pressurized air is delivered to or exhausted from the air bag to adjust the elevation of the seat. The use of an air bag permits upward and downward vibrations of the seat. To counteract these vibrations, shock-absorbing cylinders have been used to dampen the seat vibrations.
In one known approach, as the elevation of the seat suspension is changed by inflating or deflating the air bag, the shock absorbing cylinder has a piston supporting rod which extends or retracts, depending upon the direction in which the seat elevation is changed. In this approach, the shock absorbing cylinder is designed to be capable of extension and retraction throughout the entire range of seat elevation adjustment. In addition, these seat suspension systems are understood to use shock absorbing cylinders with pistons that, at a given seat velocity, apply a constant dampening force over the full stroke of the piston. If the dampening force were non-constant for a given seat velocity in such systems, problems would ensue. For example, in such systems a non-constant dampening force in response to a given velocity of seat movement would mean that the ride provided by the seat would vary depending upon the seat elevation.
U.S. Pat. No. 3,951,373 illustrates one form of seat suspension utilizing a shock absorbing cylinder and an air bag or air spring. In this construction, the shock absorber is understood to have a stroke which is capable of extending and retracting throughout the full range of seat height adjustment. However, in this construction, a hand knob may be operated to adjust the throw of a shaft to thereby change the effective length of the shock absorber.
Although numerous seat suspension systems are known, a need nevertheless exists for an improved seat support having new and non-obvious differences over known systems.
SUMMARY
In accordance with one embodiment, a seat suspension system may comprise a seat support adapted to support a seat above the floor of a vehicle. The seat support may include a seat supporting member to which the seat is mounted. The seat support and thus the seat supporting member are raisable and lowerable to support the seat at various elevations relative to the floor of the vehicle.
The seat support in one form may include a base together with a seat supporting member adapted to carry the seat. In addition, first and second link members may be included to couple the seat supporting member to the base. The link members in effect form an unequal parallelogram type linkage between the base and seat supporting member. Although sets of individual arms may be used for the first and second link members, in one specific illustrated form, they comprise respective upper and lower platform like elements. The first link member has a first end portion pivoted to the base for pivoting about a first pivot axis and a second end portion pivoted to the seat supporting member for pivoting about a second pivot axis. In addition, the second link member has a first end portion pivoted to the base for pivoting about a third pivot axis and a second end portion pivoted to the seat support member for pivoting about a fourth pivot axis. The second link member may be positioned below the first link member and may carry the air spring, with the air spring being coupled from the second link member to the seat supporting member. The first link member may include an opening through which a vibration damper extends from the base to the seat supporting member.
In accordance with one embodiment, the third pivot axis is located rearwardly of the first pivot axis and the fourth pivot axis is located rearwardly of the second pivot axis. In this case, forwardly refers to the front of the seat or direction in which an occupant faces when seated, whereas rearwardly refers to the opposite direction. In addition, in this embodiment, the distance between the third and fourth pivot axes may be greater than the distance between the first and second pivot axes. As a result, the seat support utilizes an unequal length or modified parallelogram type mechanism for carrying the seat, which does not have pivots arranged at the corners of a true parallelogram with opposed parallel sides.
More specifically, the distance between the third and fourth pivot axes in accordance with one embodiment is from about twelve percent to about twenty percent greater than the distance between the first and second pivot axes. As a result, motion of the supported seat, and in particular, a selected portion of the body of an occupant of the seat, is more vertical than in a case where the pivots are at the corners of a true parallelogram.
In one illustrated construction, the third pivot axis is at an elevation which is above the elevation of the first pivot axis and the first and second link members are angled forwardly and upwardly relative to the floor of the vehicle when the seat is in a raised position. More specifically, the absolute value of the slope of a line through the first and second pivot axes relative to horizontal may be greater than or equal to the absolute value of the slope of the line through the third and fourth pivot axes relative to horizontal, when supporting the vehicle seat in a raised position.
The first, second, third and fourth pivot axes may be located such that a plane through the first and second pivot axes intersects a plane through the third and fourth pivot axes at a location which is above the floor of the vehicle when the seat is raised to a position above the floor of the vehicle.
The pivot axes may be located relative to one another according to the formula L<(S+R−B). In this formula, L is the distance between the first and second pivot axes, S is the distance between the second and fourth pivot axes, R is the distance between the third and fourth pivot axes, and B is the distance between the first and third pivot axes.
As a further aspect of an embodiment of the seat support, the fourth pivot axis may be positioned above and rearwardly of the second pivot axis.
The location of the first, second, third and fourth pivot axes may be selected to confine the movement of a selected portion of the seat occupant's body (for example, the shoulders or head of the occupant) in a substantially vertical direction.
The seat support in one form may include a base together with a seat supporting member adapted to carry the seat. In addition, first and second link members may be included to couple the seat supporting member to the base. The link members in effect form an unequal parallelogram type linkage between the base and seat supporting member. Although sets of individual arms may be used for the first and second link members, in one specific illustrated form, they comprise respective upper and lower platform like elements. The first link member has a first end portion pivoted to the base for pivoting about a first pivot axis and a second end portion pivoted to the seat supporting member for pivoting about a second pivot axis. In addition, the second link member has a first end portion pivoted to the base for pivoting about a third pivot axis and a second end portion pivoted to the seat support member for pivoting about a fourth pivot axis. The second link member may be positioned below the first link member and may carry the air spring, with the air spring being coupled from the second link member to the seat supporting member. The first link member may include an opening through which a vibration damper extends from the base to the seat supporting member.
A seat height adjuster is coupled to the seat support and adapted to raise and lower the seat support and thereby any seat supporting member and seat between various elevations and to a selected elevation. The seat height adjuster may pivot t
Mayenburg Michael von
Ritchie Norman E.
Braun Leslie A.
Freightliner LLC
Klarquist Sparkman Campbell & Leigh & Whinston, LLP
Le Tan
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