Patent Publication Number: US-7222920-B1

Title: Adjustable chair

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
   Not Applicable. 
   STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
   Not Applicable. 
   REFERENCE TO A MICROFICHE APPENDIX 
   Not Applicable. 
   BACKGROUND OF THE INVENTION 
   1. Technical Field 
   This invention relates to chairs and, more particularly, to an adjustable chair adaptable to a size of a user&#39;s thighs. 
   2. Prior Art 
   Various types of backrests are known, including fixed backrests, inclined backrests for support of the lumbar region of the back, and height adjustable backrests. Also known are car seats and the like that are fitted with equipment to move the whole seat such as glide rails or the like. Certain office chairs are also known to be capable of adjusting their lumbar support region. 
   A conventional task chair has a standardized seat depth of approximately 40 to 43 cm. There is sufficient space on the seat surface for a person&#39;s buttocks and, depending on the size of the person sitting on the chair, a variable length of the thigh. For shorter persons, the front edge of the chair is often too far forward, so that the blood vessels in the legs are compressed by the front edge, thus hindering the blood supply to the legs. The unpleasant and unhealthy consequences are cold feet and varicose veins. To correct the seat depth, in some task chairs, the position of the backrest is adjustable; that is, the person sitting in the chair can choose how great the distance between the front edge of the chair and the backrest should be. However, if the seat surface is physiologically shaped, then a shorter person sits too far forward or a tall person sits too far to the rear on the seat surface. 
   A seat depth adjustment for motor vehicle seats is known in the prior art. In it, the seat region at the front of the seat is movable in the longitudinal direction of the vehicle. The front seat region is secured to the seat by two parallel retaining arms, which can be swiveled about a horizontal shaft fixed to the seat. Its top side is located partly under the seat surface. The retaining arms are articulated in the rear end of the moveable seat region, and an adjustable-length arm is pivotally secured to the seat at a rear shaft and articulated to the front end of the seat region. A disadvantage of this seat depth adjustment is that the retaining arms and the adjustable-length arm require shafts secured to the seat, which are disposed below and at a distance from the seat surface. Such a construction is unacceptable for task chairs for use in the office, because these arms under the seat surface are not only unattractive but do not guarantee enough space for the legs below the seat surface 
   Accordingly, a need remains for an adjustable chair in order to overcome the above-noted shortcomings. The present invention satisfies such a need by providing an adjustable chair that is easy to use and adjust, durable in design, provides sufficient thigh support to people of various lengths, and improves productivity. Such an adjustable chair prevents the circulation to a person&#39;s legs from being cut off, thus preventing the formation of varicose veins. The adjustable chair can advantageously be used in a variety of business settings, as well as in commercial vehicles, such as trucks and busses. 
   BRIEF SUMMARY OF THE INVENTION 
   In view of the foregoing background, it is therefore an object of the present invention to provide an adjustable chair. These and other objects, features, and advantages of the invention are provided by an adjustable chair adaptable to a size of a user. 
   The chair includes back and seat portions. Such back and seat portions each include a padded member directly engageable with the user when the user sits on the chair. The rear surface of the back portion is substantially planar. 
   A plurality of oppositely spaced rectilinear back support rails have axially opposed end portions and include a plurality of coextensive braces directly connected thereto respectively. Such support rails preferably have substantially L-shapes. One end portion of the back support rails has a plurality of notches formed therein. Such notches define a plurality of flange portions equidistantly spaced from a centrally located longitudinal axis of the chair. The braces traverse a rear surface of the back portion in such a manner that opposed end portions of the braces are directly conjoined to corresponding ones of the end portions of the rails respectively. 
   A seat support member has a substantially planar bottom surface and a plurality of sidewalls extending vertically up therefrom such that the sidewalls travel parallel to the longitudinal axis. Such sidewalls have a plurality of juxtaposed and equidistantly spaced notches formed along a length of a top surface thereof respectively. The notches of the sidewalls may be coextensively shaped. Such notches travel forwardly from the back portion and terminate rearward of a front edge of the seat portion. The seat support member includes a plurality of monolithically formed inner lip portions extending along a length of the sidewalls respectively. The flange portions of the back support rails are slidably engageable with such inner lip portions of the seat support member such that the back portion can effectively be maintained at a substantially stable and vertically upright position during operating conditions. 
   A shaft is directly conjoined to the seat support member. Such a shaft extends orthogonally downward from the seat support member and is disposed generally medially of the seat portion for effectively maintaining the seat portion at an elevated position during operating conditions. 
   A plurality of legs are directly conjoined to the shaft. Such legs extend radially outwardly therefrom. A plurality of casters are directly connected subjacent to the legs. 
   A mechanism is included for independently adjusting a position of the back portion forwardly above the seat support member and along a horizontal plane. Such an independently adjusting mechanism preferably includes a rectilinear and elongated rod that has a centrally disposed longitudinal axis and axially opposed end portions. Each end portion of the rod includes a monolithically formed finger member extending downward therefrom. One of the rod end portions further includes a monolithically formed lever extending vertically therefrom. 
   Such a lever is pivotal along an arcuate path traveling ninety degrees between engaged and disengaged positions. The rod extends orthogonal to the longitudinal axis of the chair and spans across a width of the seat portion. The back portion is conveniently and selectively adjustable along a horizontal plane when the lever is pivoted to an engaged position such that the finger members are positioned within one of the notches of the sidewalls. The finger member is preferably positioned medially of the notches of the sidewalls when the lever is pivoted to an engaged position. 
   There has thus been outlined, rather broadly, the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are additional features of the invention that will be described hereinafter and which will form the subject matter of the claims appended hereto. 
   It is noted the purpose of the foregoing abstract is to enable the U.S. Patent and Trademark Office and the public generally, especially the scientists, engineers and practitioners in the art who are not familiar with patent or legal terms or phraseology, to determine quickly from a cursory inspection the nature and essence of the technical disclosure of the application. The abstract is neither intended to define the invention of the application, which is measured by the claims, nor is it intended to be limiting as to the scope of the invention in any way. 

   
     BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING 
     The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings in which: 
       FIG. 1  is a side-elevational view showing an adjustable chair for optimizing the thigh support of a user, in accordance with the present invention; 
       FIG. 2  is a rear-elevational view of the apparatus shown in  1 ; 
       FIG. 3  is a cross-sectional view of the apparatus shown in  FIG. 3 , taken along line  3 - 3 ; and 
       FIG. 4  is a cross-sectional view of the apparatus shown in  FIG. 2 , taken along line  4 - 4 . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   The present invention will now be described more fully hereinafter with reference to the accompanying drawings, in which a preferred embodiment of the invention is shown. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, this embodiment is provided so that this application will be thorough and complete, and will fully convey the true scope of the invention to those skilled in the art. Like numbers refer to like elements throughout the figures. 
   The apparatus of this invention is referred to generally in  FIGS. 1-4  by the reference numeral  10  and is intended to provide an adjustable chair. It should be understood that the apparatus  10  may be used to adjust the backrest of many different types of chairs and should not be limited in use to only office chairs. 
   Referring initially to  FIG. 1 , the apparatus  10  includes a back  21  and seat  22  portions. Such back  21  and seat  22  portions each include a padded member  23  directly engageable, with no intervening elements, with the user when the user sits on the chair, which is essential for providing comfortable support to the user&#39;s buttocks and back regions. Of course, the back  21  and seat  22  portions may include alternate support surfaces other than padded members  23 , such as wicker or woven mesh material to name a few, as is obvious to a person of ordinary skill in the art. The rear surface  24  of the back portion  21  is substantially planar. 
   Referring to  FIGS. 1 through 4 , a plurality of oppositely spaced rectilinear back support rails  30  have axially opposed end portions  31  and include a plurality of coextensive braces  32  directly connected, with no intervening elements, thereto respectively, as is best shown in  FIG. 2 . Such support rails  30  have substantially L-shapes, which is important for maintaining the padded member  23  of the back portion  21  at a substantially stable position during operating conditions. Of course, the back support rails  30  may be alternately shaped, as is obvious to a person of ordinary skill in the art. 
   One end portion  31 A of the back support rails  30  has a plurality of notches  33  formed therein. Such notches  33  define a plurality of flange portions  34  equidistantly spaced from a centrally located longitudinal axis of the chair  10 . The braces  32  traverse a rear surface of the back portion  21  in such a manner that opposed end portions  35  of the braces  32  are directly conjoined, with no intervening elements, to corresponding ones of the end portions  31  of the rails  30  respectively. Such braces  32  effectively and advantageously support the padded member  23  of the back portion  21  at an upright and stable position. 
   Still referring to  FIGS. 1 through 4 , a seat support member  40  has a substantially planar bottom surface  41  that is vital for supporting a padded member  23 A thereon, and a plurality of sidewalls  42  extending vertically up therefrom such that the sidewalls  42  travel parallel to the longitudinal axis. Such sidewalls  42  have a plurality of juxtaposed and equidistantly spaced notches  43  formed along a length of a top surface  44  thereof respectively, as is best shown in  FIG. 4 . 
   The notches  43  of the sidewalls  42  are coextensively shaped, which is crucial for allowing the back portion  21  to remain straight prior to and after being adjusted to a desired setting. Such notches  43  travel forwardly from the back portion  21  and terminate rearward of a front edge  25  of the seat portion  22 . Of course, the number and spacing of the notches  43  may be altered so as to change the number of possible positions the back portion  21  may assume, as is obvious to a person of ordinary skill in the art. 
   The seat support member  40  includes a plurality of monolithically formed inner lip portions  45  extending along a length of the sidewalls  42  respectively. The flange portions  34  of the back support rails  30  are slidably engageable with such inner lip portions  45  of the seat support member  40 , which is crucial such that the back portion  21  can effectively be maintained at a substantially stable and vertically upright position during operating conditions. 
   Referring to  FIGS. 1 and 2 , a shaft  50  is directly conjoined, with no intervening elements, to the seat support member  40 . Such a shaft  50  extends orthogonally downward from the seat support member  40  and is disposed generally medially of the seat portion  22 , which is vital and convenient for effectively maintaining the seat portion  22  at an elevated position during operating conditions. Of course, the shaft  50  may be produced in a variety of alternate lengths or may be produced to be telescopically adjustable, as is obvious to a person of ordinary skill in the art. A plurality of legs  51  are directly conjoined, with no intervening elements, to the shaft  50  and extend radially outwardly therefrom. A plurality of casters  52  are directly connected, with no intervening elements, subjacent to the legs  51 . Such casters  52  are critical and advantageous for allowing the apparatus  10  to be easily transported between remote locations. 
   Referring to  FIGS. 1 through 4 , a mechanism  60  is included for independently adjusting a position of the back portion  21  forwardly above the seat support member  40  and along a horizontal plane. This is a critical feature that allows individuals with upper leg regions of varying lengths to effectively and advantageously adjust the seat portion  22  of apparatus  10  to optimally support their thighs in the sitting position such that blood flow to their lower extremities is not impeded. Such an independently adjusting mechanism  60  includes a rectilinear and elongated rod  61  that has a centrally disposed longitudinal axis and axially opposed end portions  62 . Each end portion  62  of the rod  61  includes a monolithically formed finger member  63  extending downward therefrom. One of the rod end portions  61 A further includes a monolithically formed lever  64  extending vertically upward therefrom. 
   Still referring to  FIGS. 1 through 4 , such a lever  64  is pivotal along an arcuate path traveling ninety degrees between engaged and disengaged positions. The rod  61  extends orthogonal to the longitudinal axis of the chair  10  and spans across a width of the seat portion  22 . The back portion  21  is conveniently and selectively adjustable along a horizontal plane when the lever  64  is pivoted to an engaged position such that the finger members  63  are positioned within one of the notches  43  of the sidewalls  42 . The finger member  63  is positioned medially of the notches  43  of the sidewalls  42  when the lever  64  is pivoted to an engaged position, as is best shown in  FIG. 4 . Of course, the apparatus  10  may be provided with an automated seat adjusting mechanism including electric motors, serrated gears and serrated tracks, as is obvious to a person of ordinary skill in the art. 
   While the invention has been described with respect to a certain specific embodiment, it will be appreciated that many modifications and changes may be made by those skilled in the art without departing from the spirit of the invention. It is intended, therefore, by the appended claims to cover all such modifications and changes as fall within the true spirit and scope of the invention. 
   In particular, with respect to the above description, it is to be realized that the optimum dimensional relationships for the parts of the present invention may include variations in size, materials, shape, form, function and manner of operation. The assembly and use of the present invention are deemed readily apparent and obvious to one skilled in the art.