Supports – Resilient support – Including additional energy absorbing means – e.g. – fluid or...
Reexamination Certificate
1999-05-06
2001-02-13
King, Anita M. (Department: 3632)
Supports
Resilient support
Including additional energy absorbing means, e.g., fluid or...
C248S577000, C248S404000, C248S157000, C248S161000, C248S162100, C248S188600
Reexamination Certificate
active
06186467
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention pertains to adjustable seat suspensions, particularly for vehicles, wherein the seat is mounted upon a scissors linkage, and the supporting biasing force for the seat is adjustable over a wide range.
2. Description of the Related Art
Off road equipment such as lift trucks, backhoes, Bobcats, and the like, often utilize a spring supported seat to cushion the driver during vehicle operation. Such cushioning usually utilizes extension or compression springs which support the driver's weight. However, because of variations in the driver's weight, often in excess of 100 pounds, it is difficult to “tune” a spring supported seat suspension to provide optimum comfort. Accordingly, it is known to employ seat suspensions utilizing extension or compression springs wherein the biasing force imposed by the springs on the seat structure is adjustable.
In my U.S. Pat. No. 5,601,338, I disclose a vehicle seat structure with an adjustable suspension of the extension spring type. In this patent, the seat is pivoted at its forward edge, and the rear edge is supported by a pair of extension springs. An adjustably positionable slide located upon a lever arm is interposed between the springs and the seat rear portion wherein adjustment of the slide upon the lever means varies the extent of spring biasing force by changing the location of the application of the biasing force to the lever, and in this manner, the seat disclosed in U.S. Pat. No. 5,601,338 may be adjusted to provide an operative suspension for a wide weight range of vehicle operators.
In U.S. Pat. No. 5,601,338, only the seat bottom is capable of suspension, but in some applications wherein large shocks or impacts are transmitted to the seat structure through the vehicle, it is desirable to have greater support and impact absorption than is possible with the prior art devices.
Further, to achieve maximum comfort in a spring supported seat having a back, it is highly desirable that both the back and seat portions move in unison during suspension, and in the prior art, a full seat adjustable suspension device capable of utilization with a wide range of weights of users has not been readily available.
OBJECTS OF THE INVENTION
It is an object of the invention to provide a full seat adjustable suspension wherein the biasing force provided by springs may be varied over a wide range of adjustment, and both the seat bottom and back are suspended and will operate in unison.
An additional object of the invention is to provide a spring suspended seat using a pair of extension springs to produce an adjustable biasing force on a seat bottom and back wherein the suspension force may be easily adjusted, and the operating mechanism for the seat is simple and dependable in operation.
Yet another object of the invention is to provide a full seat adjustable suspension utilizing scissor or other linkages wherein the seat moves in a vertical direction during suspension, is supported upon extension springs, and adjustment is provided by adjusting the location of the biasing force with respect to a seat supporting lever pivot.
SUMMARY OF THE INVENTION
The seat in accord with the invention includes base structure which is horizontally mounted upon the seat support, usually a vehicle such as a tractor, lift truck, or other piece of industrial equipment. The base structure is normally formed of sheet steel and includes spaced rails having guides adjacent the base front edge, and linkage pivots are defined adjacent the base rear edge. A vertically extending spring support arises from the base at the rear edge thereof having an upper region serving as a support for the seat suspension springs.
A scissors linkage is supported upon the base. This linkage includes a pair of pivotally interconnected levers, each defining a set, and the lower end of one set lever is pivotally connected to the rear portions of the base, while the lower portion of the other lever of each set includes a pivot follower located within a base guide wherein the levers of each linkage set are capable of pivoting to change the angular relationship of the levers of a set to raise and lower the set's pivots axes.
A seat frame includes linear pockets affixed to the seat frame front edge receiving followers affixed to the upper ends of the scissor linkage levers pivotally mounted to the base, and at a location spaced from the pockets' spring biased arms engage the underside of the seat frame to resiliently support the frame. In most cases, the seat frame will include a back rest portion, and the bottom cushion and the back cushion for the seat will be mounted upon the seat frame bottom and seat frame back.
Adjustment of the supporting spring biasing force is through a U-shaped lever whose base is pivotally mounted to the upstanding base structure, and the outer free ends constituting the arms of the lever structure engage the underside of the seat frame wherein an upward force upon the lever arms will tend to raise the seat frame. The lever arms are biased upwardly by a slide adjustably positionable along the length of the arms to which the extension springs are attached at their lower end. The upper end of the extension springs is affixed to the upstanding base mounted spring support upper region.
The slide is adjusted along the lever arms by a cable system operated by an adjusting screw mounted upon the seat frame wherein the operator may quickly locate the slide upon the arms to produce the desired degree of suspension biasing force as determined by the weight of the person to be supported by the seat frame. An indicator permits the slide to be preadjusted as desired.
As the seat frame is mounted upon the scissors linkage, the seat frame suspension movement in a vertical direction is approximately linear providing occupant comfort and expected movement with respect to operating pedals and the like. The fact that the seat back is suspended for movement with the seat bottom provides excellent comfort to the user at all stages of suspension.
A feature of the structure of the invention arises from the fact that the upper end of the scissors lever whose lower end is pivotally and translatably mounted within the base guides is that such linkage upper end is located within a slot defined in the base mounted spring support. This relationship between a scissors linkage lever and the base permits ease of operation of the rather complex linkage structure while imparting to the scissors linkage a rigidity which permits safety seat belts to be affixed to the seat structure, rather than being anchored to the vehicle frame, as is the usual case. Arcuate slots are defined in the base spring anchor structure receiving pivots mounted upon the upper ends of scissors links, and the cooperation of such links' upper ends and the slots provides a high strength mechanical connection permitting seat belts to meet industry requirements while affixed to the seat structure. Such an arrangement is particularly desirable with adjustable seats to prevent the seat belts from imposing discomfort upon the wearer due to horizontal adjustment and vertical movement of the seat structure.
REFERENCES:
patent: 974769 (1910-11-01), Hoff
patent: 2531572 (1950-11-01), Knoedler
patent: 2840140 (1958-06-01), Harrington
patent: 3743230 (1973-07-01), Freedman
patent: 4382573 (1983-05-01), Aondetto
patent: 4448386 (1984-05-01), Moorhouse et al.
patent: 4611783 (1986-09-01), Sakamoto
patent: 4640488 (1987-02-01), Sakamoto
patent: 4687250 (1987-08-01), Esche
patent: 4856763 (1989-08-01), Brodersen et al.
patent: 5176356 (1993-01-01), Lorbiecki et al.
patent: 5388801 (1995-02-01), Edrich et al.
patent: 5580027 (1996-12-01), Brodersen
patent: 5601338 (1997-02-01), Wahls
patent: 5799922 (1998-09-01), Timms et al.
patent: 5957426 (1999-09-01), Brodersen
patent: 5984410 (1999-11-01), Brodersen
King Anita M.
Michigan Seat Company
Wujciak, III A. Joseph
Young & Basile P.C.
LandOfFree
Full seat adjustable suspension does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Full seat adjustable suspension, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Full seat adjustable suspension will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2579030