FIELD OF THE INVENTION 
     The present invention relates to seating assemblies, and more particularly to an ergonomic seat assembly and method particularly well adapted for use in mobile platforms. 
     BACKGROUND OF THE INVENTION 
     Mobile platforms, and particularly commercial aircraft, employ a plurality of seats arranged in rows. Typically, each row comprises two or more seats disposed adjacent one another. With many mobile platforms, and especially with commercial aircraft, passengers traveling on the mobile platform wish to perform work tasks such as using a laptop computer and various other tasks which are performed more easily in an upright seated position. Additionally, passengers, or even crew members, on a mobile platform often are required to sit for long periods of time. With many conventional aircraft seats, the occupant is only afforded a small range of seating positions between a relatively upright position and a reclined position. However, it would be of additional benefit to passengers and crew members if yet another seating position could be provided which takes the stress off the lower back of the passenger/crew member. 
     Another drawback with some seats used on commercial aircraft is that the seat back portion of the seat cannot be brought into a fully vertical position. With many seats typically used on mobile platforms, especially commercial aircraft, the seat back portion of the seat, when in its fully upright position, still assumes somewhat of a slightly reclined orientation, thereby taking up a small amount of space in the row behind a given seat. Accordingly, it would be of even further benefit if each seat on a mobile platform was able to have its seat back portion moved into a fully upright (i.e., fully vertically oriented) position. This would even better facilitate ingress and egress to the seats located behind a given seat. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a seat apparatus and method of forming same in which a leg support assembly is provided which allows the seat occupant to assume a more upright position while performing various tasks, such as working on a laptop computer. The leg rest assembly also alleviates stress and strain on the lower back of the seat occupant by accommodating a portion of the weight of the seat occupant. 
     In one preferred form the seat apparatus further includes linkage that enables a seat back of the seat apparatus to be drawn into a fully upright (i.e., fully vertical) position which further enhances ingress/egress to the seats positioned behind a given seat apparatus. 
     While the apparatus and method of the present invention is particularly well adapted for use in mobile platforms, it will be appreciated that the seat apparatus can be adapted for use in any structure where it is desired to provide individuals with a variety of seating positions to better facilitate various work tasks, as well as to provide additional seating comfort to the individuals. 
     Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the invention. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become more fully understood from the detailed description and the accompanying drawings, wherein: 
     FIG. 1 is a view of a mobile platform in the form of a commercial aircraft illustrating a plurality of seat apparatuses each in accordance with a preferred embodiment of the present invention; 
     FIG. 2 is an enlarged perspective view of one of the seat apparatuses shown in FIG. 1; 
     FIG. 3 is a partial side cross sectional view of the seat apparatus of FIG. 2 taken in accordance with section line  3 — 3  in FIG. 2 illustrating a linkage assembly used to manipulate and position the seat portion and seat back of the seat apparatus, with the seat back further being shown in a reclined position; 
     FIGS. 4 and 5 illustrate a plan view of a portion of the seat of FIG. 3 showing how the selector is moved out of its detent position; 
     FIG. 6 is an enlarged view of a portion of the aft link illustrating the torsion spring associated therewith. 
     FIG. 7 shows the seat apparatus of FIG. 2 with the seat portion being moved into its lifted position; 
     FIG. 8 is a side view of the seat apparatus of FIG. 3 showing the seat back in its fully upright position with the seat portion raised; 
     FIG. 9 is a side cross sectional view of the seat apparatus of FIG. 2 showing the leg rest portion of the seat apparatus in its extended position for supporting a portion of the weight of an individual seated in the seat apparatus; 
     FIG. 10 is a side cross sectional view of the seat of FIG. 9 but with the leg rest portion in a fully retracted position; 
     FIG. 11 is a plan view of a portion of the leg rest assembly; and 
     FIG. 12 is a perspective view of an alternative leg rest assembly incorporating a pair of separate leg rest members. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following description of the preferred embodiment(s) is merely exemplary in nature and is in no way intended to limit the invention, its application, or uses. 
     Referring to FIG. 1, there is shown a plurality of seat apparatuses  10 , each in accordance with the preferred embodiment of the present invention, arranged in a plurality of rows. The seat apparatuses  10  are adapted to be fixedly secured to a floor surface  12  of a structure, in this example, a mobile platform  14  in the form of a commercial aircraft. It will be appreciated immediately, however, that the seat apparatus  10  could be used in any structure where it is desired to provide seat occupants with a plurality of seating positions. It is anticipated, however, that the seat apparatus  10  of the present invention will find particular utility in mobile platforms that carry passengers significant distances, and where the ability to provide passengers and crew members with a plurality of seating positions to better enable the seat occupants to accomplish various work tasks while seated, as well as to increase the comfort of the seat occupants over a period of time, will be important. 
     Referring to FIG. 2, each seat apparatus  10  includes a frame portion  16  which allows the seat apparatus  10  to be secured fixedly to the floor  12  of the mobile platform to which the seat apparatus is mounted. Coupled to the frame  16  are a pair of arm portions  18 . A seat portion  20  is also supported by the frame  16 , as is a seat back  22 . A leg rest assembly  24  (shown in its retracted position) having a pull out handle  24   a  is further provided so as to reside generally beneath the seat portion  20  when in its fully retracted position. Positioned adjacent to the leg rest assembly  24  is a selector lever  26  which, as will be explained more fully in the following paragraphs, enables the seat apparatus  10  to be articulated between its various operative positions. 
     Referring to FIG. 3, the seat apparatus  10  is shown without the leg rest assembly  24  for purposes of better illustrating those components which enable articulation of the seat portion  20  and the seat back  22 . The selector lever  26  is coupled at a first end  28  to a torque rod  30 , which is in turn supported from side arm portion  18 . The selector lever  26  also includes a detent member  32  formed at a midpoint of a flexible elongated member  32   a , and is disposed adjacent a forward portion  20   a  of the seat portion  20 . With brief reference to FIGS. 4 and 5, the selector lever  26  can be seen in further detail. The detent member  32  fits within a lower detent recess  32   b  in arm structure  18  to hold the seat  20  in the position shown in FIG.  2 . Pushing inwardly (i.e., toward the opposite lateral side of the seat apparatus  10 ) on a handle portion  26   a  of the selector lever  26  in accordance with arrow  33  releases the detent member  32  from detent recess  32   b , as shown in FIG. 5, thus allowing the seat portion  20  to be urged into its elevated position (FIG.  7 ). 
     With further reference to FIG. 3, the seat structure  18  includes an upper detent recess  32   c  into which the detent member  32  engages when the seat portion  20  is urged into its raised position. A lateral link  16   a  forming a portion  20   b  of the seat is pivotally coupled via a pivot pin  34  to a first end  36  of an aft link  38 , and at a forward end thereof to the selector lever  26 . The aft link  38  is fixedly coupled at an intermediate point  40  to a torque rod  42 , adjacent a rear portion  16   b  of the frame  16 . Thus, aft link  38  is able to pivot in response to rotational movement of the torque rod  42  in the direction of arrow  44 . The torque rod  42  is supported from seat side arm portion  18 . 
     With brief reference to FIG. 6, a torsion spring  42   a  is disposed on the torque rod  42 , with its ends coupled to the aft link  38  and a portion of the arm portion  18 . The torsion spring  42   a  provides a biasing force that tends to urge the aft link  38  rotationally in accordance with arrow  44  in FIGS. 3 and 7 (i.e., clockwise in these Figures). 
     With further reference to FIG. 3, a second end  46  of the aft link  38  is pivotally coupled via a pivot pin  48  or like member to a first end  50  of a coupling link  52 . A second end  54  of the coupling link  52  is coupled via a pivot pin  56  to a lower edge  22   a  of the seat back  22 . Seat back  22  is further pivotally coupled at a rearward portion  16   c  to the coupling link  52  via a pivot pin  58 . Accordingly, the entire seat back  22  is able to pivot rotationally about pivot pin  58  between a reclined position shown in FIG.  3  and the upright position as shown in FIG.  4 . Torque rods  30  and  42  extend to, and are coupled to a second pair of links  26 ,  38  and  52  at the opposite side of the seat apparatus  10  to support the seat portion  20  and seat back  22  at the opposite side of the seat apparatus  10  also. FIG. 7 is a view of the seat apparatus  10  of FIG. 3 but with the seat apparatus in its intermediate position as the seat back  22  thereof is moved into a fully upright position. 
     With further reference to FIGS. 3,  5  and  7 , operation of the seat apparatus  10  will now be described. The position shown in FIG. 3 represents a slightly reclined seating position for the seat occupant. When it is desired to use the leg rest assembly  24 , the user pulls inwardly (along line  33  in FIG. 5) on the selector level  26  to move detent  32  out of the recess  32   a . This allows the torsion spring  42   a  (FIG. 6) to urge the selector lever  26  clockwise, via lateral movement of lateral link  16   a , and the seat portion upwardly in accordance with directional arrow  64  (FIG.  3 ). This also causes the forward edge  20   a  of the seat portion  20  to be moved forwardly in accordance with directional arrow  62  (FIG.  3 ). 
     Referring to FIG. 7, the seat apparatus  10  is shown in its intermediate position as the selector lever  26  is being rotated to its fully raised position by the biasing force of the torsion spring  42   a . The combined rotational movements of selector lever  26  and aft link  38  serve to lift the forward edge  20   a  of the seat portion  20  upwardly while also substantially simultaneously lifting a rear portion  20   b  of the seat portion  20  upwardly to an even greater degree than the front portion  20   a , as noted in FIGS. 7 and 8. 
     With specific reference to FIGS. 7 and 8, as continued rotation of the selector lever  26  and aft link  38  occurs, the rotational movement of the aft link  38  in accordance with directional arrow  44  simultaneously causes the second end  54  of the coupling link  52  to be pushed generally in the direction of arrow  67 , which in turn causes the seat back  22  to pivot about pivot pin  58  into the fully upright position shown in FIG.  8 . The seat back  22  reaches the fully upright position in FIG. 8 just as the selector lever  26  is urged into its fully upright position shown in FIG. 8, and into detent recess  32   b . It will be appreciated that when the seat back  22  is in the position shown in FIG. 8, ingress and egress to/from seats located behind the seat apparatus  10  is significantly improved. 
     Referring now to FIGS. 9 and 10, the construction and operation of the leg rest assembly  24  will be described. Leg rest assembly  24  includes a leg rest member  68  (also shown in FIG. 11) having a padded portion  70  upon which the knees of the seat occupant can rest when the leg rest assembly is in its operative position shown in FIG.  9 . The leg rest member  68  is pivotally coupled by a pivot pin or leg member  72  at an intermediate portion  74  to a mounting portion  76  of a frame member  78 . Frame member  78  is supported by a pair of rollers  80  that are coupled to a frame element  82 . The frame element  82  is fixedly coupled to, and forms a portion of, the seat portion  20 . The wheels  80  allow the frame member  78  to move slidably between the positions shown in FIGS. 9 and 10. A biasing spring  84  is coupled to the mounting portion  76  at a first end  84   a  and to a mounting flange  86  associated with the frame element  82  at a second end  84   b.    
     With further reference to FIGS. 9 and 10, in operation, the user brings the leg rest assembly  24  into the operative position shown in FIG. 9 by pulling forwardly on the pull out handle  24   a  until the frame member  78  is in its fully forwardly extending position, as shown in FIG.  9 . The user then kneels on the padded portion  70  of the leg rest member  68 . To place the leg rest assembly  24  into its stowed position shown in FIG. 10, the user lifts his/her legs from the leg rest member  68  to allow it to be drawn into the fully stowed position by the biasing member  84 , as shown in FIG.  10 . As the frame member  78  is retracted into the fully stowed position in FIG. 10, an upper surface  68   a  of the leg rest member  68  abuts a lower portion  86  of the seat portion  20  and rotates counterclockwise in the drawing of FIG. 9 as it is urged into the fully retracted position of FIG.  10 . The force provided by the biasing member  84  is selected such that the leg rest assembly  24  can be easily pulled into the position shown in FIG. 9 with a minimal degree of effort by the seat occupant. 
     It will be appreciated that while the seat apparatus  10  has been described as having the seat back  22  in the fully upright position when the leg rest assembly  24  is in use, that the leg rest assembly does not need to be in its fully extended (i.e., operative) position when the seat back  22  is positioned in its fully upright position. Thus, the occupant, if he or she so chooses, can just as readily sit with the seat apparatus  10  in the position shown in FIG. 10 without using the leg rest assembly  24 . 
     The seat apparatus  10  of the present invention thus provides a seat occupant with a number of different seating positions which can add to the comfort of the occupant in the event the occupant is required to be seated for extended periods of time. The extendable leg rest assembly  24  of the present invention further enhances utility of the seat apparatus  10  by providing the user with a comfortable position that relieves pressure on the lower back of the occupant, and which further enhances the ease with which the occupant may use a laptop computer or other component positioned on a pull down tray of the seat in front of the occupant. Still further, it is anticipated that many individuals will find the seated position shown in FIG. 10 to be comfortable for eating meals positioned on a pull down tray of the seat in front of the occupant. 
     It is a further advantage of the seat apparatus  10  that same significantly eases the ingress/egress to and from seats positioned behind the seat apparatus  10 , thus expediting boarding and de-planing on a commercial aircraft or on other mobile platforms where movement through the limited spaces between rows of seats can be difficult. 
     Yet another advantage of the seat apparatus  10  is that the apparatus does not increase the envelope or the footprint over that of conventional seats typically employed on mobile platforms such as commercial aircraft. Thus, the seat apparatus  10  is anticipated to be retrofittable to a wide number of mobile platforms, and more particularly to a wide variety of commercial aircraft. 
     Referring now to FIG. 12, there is shown a leg rest assembly  100  in accordance with an alternative preferred form of the present invention. The leg rest assembly  100  is coupled by frame members  102  at outwardly facing portions  104  of a pair of leg rest members  106 . The frame member  102  can be supported by a suitable arrangement of rollers similar to that described in connection with the seat apparatus  10  of FIGS. 9 and 10. It will be appreciated that other variations of the leg rest assembly could also be incorporated. 
     The description of the invention is merely exemplary in nature and, thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations are not to be regarded as a departure from the spirit and scope of the invention.
A seat apparatus and method particularly well adapted for use in mobile platforms, and more particularly in a commercial aircraft. The seat apparatus includes a seat portion with linkage that enables a user to lift and tilt the seat portion forwardly while simultaneously moving a seat back of the apparatus from a reclined to a fully upright position. An extendable leg rest assembly allows the user to kneel thereon to further relieve lower back stress during prolonged periods of seating and to better enable the seat occupant to make use of a laptop computer or other equipment positioned in front of the occupant. The seat apparatus therefore provides a plurality of different seating positions for the occupant, thus enhancing the comfort of the occupant during prolonged seating periods and while the seat occupant is performing various tasks.