Abstract:
A tray and tray support system which is suited for attachment to a portable folding chair enables the tray mechanism to be either left closely adjacent to the portable seating and unused, or pivoted to a position of deployment. Deployment is effected by causing a tray suspended from a fitting to be pivoted from a vertical hanging position and through an angle of about 270° to then be stably supported at a general horizontal position. The responsibility for pivoting support is divided and uses a pivot stop structure within a tray deployment fitting, and a set of tray supports which are also pivotally attached to the tray deployment fitting about an axis adjacent and parallel to the axis of the main horizontal extent of the main tray bearing member.

Description:
FIELD OF THE INVENTION  
       [0001]    The present invention relates to a deployable and stowable tray mechanism for use with any support structure and which can be adjusted to a first position as a side support position to one side to allow a user to rise and re-seat freely, and to a second position where the table is brought to a stable supported position and which may be immediately before a seated user. 
       BACKGROUND OF THE INVENTION  
       [0002]    The term “tray” and “tray support system” and “tray mechanism” includes a mechanism for deployment and stowage of a generally horizontal surface for supporting food and drink, for writing upon and for supporting reading materials, to name a few. The use of folding tray support mechanisms has been found to be beneficial in airline seating, university classroom seating, and highly specialized, and virtually always non-moveable or non-portable seating, which allowed a good number of tray structures to develop from its own support, apart from the seating. Airline seating uses a well-stowed, highly articulating tray support system for bulkhead seats. The overall bulkhead stowage apparatus for airlines needed to have a weight savings to justify the fuel consumption involved in multiple flights, but due to airline safety regulations, the tray mechanism cannot be insubstantial and must not present a hazard in an emergency. 
         [0003]    None of the aforementioned tray and tray support mechanisms is suitable for carriage with general use seating and particularly portable seating, sometimes known as a folding chair. First, where seating is foldably deployed, a needed tray support mechanism should be compatible with the deployment and stowage mechanism of the seating. Where seating collapses in a direction which leaves the tray or tray mechanism protruding, an unwieldy partially structure will result. 
         [0004]    Second, the overall weight of the tray and tray support must be minimally additive to the weight of the portable seating. The portable seating will typically have a significant portion of its carriage by hand, and so the resulting overall weight should not be significancy more then the overall weight of the portable seating without the tray and the tray&#39;s supporting structure. 
         [0005]    Third, the overall structural dependency from the supporting portable seating should not be compromised. A tray and tray mechanism for a portable seat should enable very nearly the same user reliance on use of the tray and its support for writing, reading and support of food and drink on the tray. All support should be stable, but particularly stable when the portable seating is occupied in supporting the weight of a user, and also capable of stability when the portable seating is unoccupied, and especially when ultra-light seating is utilized and where tipping over might be an issue. 
         [0006]    Fourth, an ideal tray mechanism should ideally have a high range of chair types and associated structures with which it may be implemented. This includes both original equipment manufacture as well as retrofit applications. Detachability is important for fulfilling the utility functions of the user, as there are instances where the user may wish to have the ability to detach the tray mechanism and leave it at home, or to have a more compact cache of tray mechanisms to attach to seating when they are needed. Maximizing the capability to increase user preference can make a tray mechanism for portable seating more valuable. 
       SUMMARY OF THE INVENTION 
       [0007]    This invention relates to a tray and tray support system which is ideally suited for attachment to a vertical member of a portable folding chair. The method of attachment enables the tray mechanism to be either left closely adjacent to the portable seating and unused, or pivoted to a position of deployment. Deployment is effected by causing a tray suspended from a fitting to be pivoted from a vertical hanging position and through an angle of about 270° to then be stably supported at a general horizontal position. 
         [0008]    The ability to pivot is accomplished through a pivot stop structure. The pivot stop structure which occupies about 165° of arc and engages a stop occupying about 63° of arc after rotating about an angle of about 130°. A tray depends from a pair of supports which are pivotally connected to a pivot fitting which sets the axis of pivot as spaced from an axis of pivot from the pivot stop structure, and which uses the bearing presence of the pivot stop structure upon which to stably rest the pair of supports after pivoting through an angle of about 140°. The total angular displacement of the pivot stop structure angle of about 130° and the pivot fitting angle of about 140° to produce a total angular displacement of about 270°. 
         [0009]    The pivot stop structure will generally be mounted to depend from portable seating so that it is generally horizontal. In one embodiment, especially amenable for retrofit capability, the pivot stop structure has a horizontal main extent and a vertical main extent which attaches to a mounting bracket. The vertical extent and bracket attach to a vertical member on portable seating. The right angled portion, by virtue of its connection to a non-horizontal member of the portable seating, provides a sturdy resistance to the turning moment applied to the pivot stop structure when the tray is in the horizontal position. Other attachment methods and other structures which can provide an anti-turning support in the pivot stop structure may be employed. 
       BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]    The invention, its configuration, construction, and operation will be best further described in the following detailed description, taken in conjunction with the accompanying drawings in which: 
         [0011]      FIG. 1  is a perspective overall view of one example of a seating structure, such as a portable seating structure shown in the folded or stowed position to illustrate a further advantage of the table structure of the present invention and its compatibility in a stowed hanging position generally gravitationally urged flat against the folded chair; 
         [0012]      FIG. 2  is a view similar to that shown in  FIG. 1  but where the portable seating is seen in an un-folded or deployed position generally ready for use as seating as would be the case for non-portable seating and in which the tray system is still shown in a hanging position but having its horizontal main extent pivoted about its vertical main extent from a rearward position lying alongside the chair arm to a forward position extending in front of the chair but again generally parallel to the chair arm; 
         [0013]      FIG. 3  is a perspective view similar to that seen in  FIG. 2 , but wherein the tray of the tray system has been flipped from a vertical position toward the center axis of the chair, through a first horizontal position and then to a second stable horizontal position, having been flipped or pivoted 270° from its vertical gravity resting position to a supported horizontal position in which the tray can be utilized for support of other objects, but forward and to the side of the portable chair where the tray support system is mounted; 
         [0014]      FIG. 4  is a perspective view similar to that seen in  FIG. 5  in which the tray support system is rotated about its vertical main extent while supported by its bracket, and to position in which the horizontal main extent is positioned most closely to a position of a seated person if present, with the supported tray extending from the main horizontal extent away from the back of the portable seating and in a position to support food items directly in front of the person (not shown) if seated in the chair; 
         [0015]      FIG. 5  is a perspective closeup view probably from the center of the chair, and looking down into the inside of the tray system and focussing on the fitting and illustrating further details of the tray system structure; 
         [0016]      FIG. 6  is a perspective exploded view of the assembly seen in  FIG. 5 ; 
         [0017]      FIG. 7  is a view from the rear of the fitting attached to the front vertical support of the portable seat, from which the tray system structurally depends; 
         [0018]      FIG. 8  is a partially exploded view which illustrates the operation of the cam mechanism to allow the main vertical extent to pivot, raise and lower with respect to the support fitting attached to the front vertical support of the seat; 
         [0019]      FIG. 9  is a sectional view taken along line  9 - 9  of  FIG. 2  and showing the state of the internal and external pivot limiting components of tray support system and tray in a position suspended in a vertical position and at rest; 
         [0020]      FIG. 10  is a sectional view taken along line  10 - 10  of  FIG. 2  similar to the sectional view as seen in  FIG. 9  but showing the state of the internal and external pivot limiting components of tray support system and tray in a position after having been pivoted through an angle of 270° ending with the tray in a horizontal resting position; 
         [0021]      FIG. 11  is a sectional view taken along line  11 - 11  of  FIG. 4  and showing the tray system support fitting in a locked position; and 
         [0022]      FIG. 12  is a sectional view taken along line  12 - 12  of  FIG. 4  and showing the tray system support fitting in an unlocked position. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0023]    Referring to  FIG. 1 , a perspective overall view of a seat  21  is shown in folded position. A typical seat may or may not be portable (such as a permanently anchored but deployable seat), may or may not be foldable, and it may have base seating structures in addition to those seen in  FIG. 1 . Conversely the base seating structure portions of  FIG. 1  may have features not seen in other base seating structures with which the invention may be utilized. Seat  21  is shown as folded to a laterally compact shape. Details of seat  21  are set forth to illustrate but a single seating environment of many in which the invention may operate. A pair of lateral seat supports  23  and  25  are shown as brought together in close proximity with no change in their front to back length. The generally horizontal seat support  23  is connected to a front generally vertically extending cross support  27  and a rear generally vertically extending cross support  29 . Likewise, the generally horizontal seat support  25  is connected to a front generally vertically extending cross support  31  and a rear generally vertically extending cross support  33 . 
         [0024]    A first horizontally extending arm  35  is connected to a front vertical support  37  and a rear vertical support  39 . 
         [0025]    A second horizontally extending arm  35  is connected to a front vertical support  41  and a rear vertical support  43 . A rear seat back support  45  is connected to generally horizontal seat support  23 , and a rear seat back support  47  is connected to generally horizontal seat support  25 . In the unfolding of the seat  21 , a connected cloth material may generally be used to set the limits over which the seat  21  will unfold. These may be generally seen as a bottom seating suspension material  51  which is connected to and extends between pair of lateral seat supports  23  and  25 , and a back seating suspension material  53  which is suspended between rear seat back supports  45  and  47 . 
         [0026]    Hereinafter, components attached to the seat  21  to form a tray system  55  of the invention will be described. A tray system support fitting  61  is seen attached to the vertical support  41  and a portion of its body partially covers and is secured to the vertical support  41 . It is understood that tray system support fitting  61  could fit onto a variety of other structures provided on other forms of seating and that seat  21  is but one example. Tray system support fitting  61  is attached to vertical support  41  with an attachment member  63  which may preferably penetrate tray system support fitting  61  and the vertical support  41  and may be a rivet or threaded member or locking pin, to name a few. On the right side of the tray system support fitting  61 , a moveable locking clip  65  is seen. Locking clip  65  may be pivotable over and onto a portion of the tray system support fitting  61  to increase compression or constriction of a portion of the tray system support fitting  61  or pivotable free of a portion of the tray system support fitting  61  to release such compression or restriction. 
         [0027]    Tray system support fitting  61  is seen as having a portion of its body partially surrounding and pivotally supporting a main tray bearing member  71  its main vertical main extent  73 . The main vertical extent  73  transitions into a main horizontal extent  75  preferably through a gradual curved corner. A lower cap  77  is seen at the bottom most portion of the vertical main extent  73 . 
         [0028]    From the main horizontal extent  75 , a pair of spaced apart tray deployment fittings  81  can pivotally rotate over a limiter range. From each of the pair of spaced apart tray deployment fittings  81  a pair of supports  85  have first ends pivotably connected to the pair of spaced apart tray deployment fittings  81 . The pair of supports  85  have second ends which are attached to one side of a tray  91 . Tray  91  is seen from its underside in  FIG. 1  and tray  91  is shown as having a structural support grid  93  so that a lighter weight table  91  can be provided which is still strong enough to maintain an acceptable support weight. The pair of supports  85  second ends are generally rigidly attached to one side of a tray  91 . Rigid attachment of the pair of supports  85  second ends can be had by bolting using threaded members as well as by forming the tray  91  by injection molding around the pair of supports  85  second ends during injection molding, with appropriate structures at and adjacent the ends of the pair of supports  85  to enable a good connection. 
         [0029]    A pivoting attachment which can provide a pivoting rotation of 270° with good holding force is generally difficult to achieve, but is provided in the tray system  55  by both splitting the components which must accommodate the rotation, as well as by using the shape and diameter of the tray deployment fittings  81  and the pivot point provided on the tray deployment fittings  81  spaced apart from the main horizontal extent  75  to provide a location and mechanics for the pair of supports  85  to be supported. This deployed final resting location is based upon the limited angular displacement of the tray deployment fittings  81  with respect to the main horizontal extent  75 , as well as the limited angular displacement of the pair of supports  85  with respect to the tray deployment fittings  81 . 
         [0030]    The overall movement capabilities of the tray system  55  of the invention will first be shown with regard to the capabilities as they appear to the user, and then sectional drawings illustrating the inner workings of the various fittings which allow such capabilities will be illustrated in Further detail. As before,  FIG. 1  illustrates the seat  21  in a folded position to occupy less lateral space. The advantage of this position is that it can be attached more flatly to other structures, or more easily carried, more easily stored, or simply to provide additional space for other items adjacent the tray system  55 . However, referring to  FIG. 2 , a perspective view similar to that shown in 
         [0031]      FIG. 1  but where the seat  21  is seen in an un-folded or deployed position generally ready for use as seating and in which the tray system  55  is still shown in a hanging position but having its horizontal main extent  75  pivoted about its vertical main extent  73  from a rearward position lying alongside and closely adjacent the chair arm  35  as seen in  FIG. 1 , to a forward position extending in front of the seat  21  but again generally parallel to the closest chair arm  35 . 
         [0032]    Movement to this position is generally preceded by opening release of moveable locking clip  65 , and a re-locking of the moveable locking clip  65  once the position seen in  FIG. 2  is achieved, or perhaps after further pivoting of the tray system  55  to a more inward position with regard to the seat  21 . In the position seen in  FIG. 2 , where the tray system  55  and tray  91  is in the vertical position, the seat  21  is stable and the tray system  55  is not deployed in such a way that it can accept a load. Other aspects of the invention seen for the first time in  FIG. 2  include an end cap  95  to cover the open end of the main horizontal extent  75  of the main tray bearing member  71 . Also seen is a flat surface  97  of the tray  91 , with flat surface  97  interrupted by a slight circular depression  99 . 
         [0033]    Regardless of whether or not the seat  21  would be occupied, further deployment steps are likely to occur. From the position seen in  FIG. 2 , the tray  91  will be flipped or rotated generally about the main horizontal extent  75 , but in reality flipped or rotated about a combination of two axes before achieving the final position shown in  FIG. 3 . Tray deployment fittings  81  rotate generally about the center of the main horizontal extent  75 . Further pivoting or rotation occurs about the pivoting connection between the pair of supports  85  and their pivoting connection to the tray deployment fittings  81  about a pivot point somewhat outside the surface of the main horizontal extent  75 . The result of the rotation or flipping of the tray  91  is seen in  FIG. 3 . 
         [0034]    Referring to  FIG. 3 , a perspective view similar to that seen in  FIG. 2  is seen. An arrow illustrates that the general displacement of the tray  91  occurs along the horizontal axis of main horizontal extent  75  of the main tray bearing member  71  through about 270°, from a vertically hanging position, to a vertically upright position, and continuing through to a horizontal position seen in  FIG. 3 . As can be seen, the pair of supports  85  are bearing down upon a portion of the tray deployment fittings  81  which are spaced apart from the point of pivoting connection the pair of supports  85  have with respect to the tray deployment fittings  81 . In the position shown, the tray  91  can be used to support small, lightweight items while leaving the area in front of an individual, were an individual seated in the seat  21 , open. 
         [0035]    Referring to  FIG. 4 , a perspective view similar to that seen in  FIGS. 2 and 3  is seen. An arrow in the horizontal plane illustrates a pivoting displacement of the tray  91  occurs about the axis of the main vertical main extent  73  while the moveable locking clip  65  remains in the open, unlocked position. The view of  FIG. 4  illustrates a 90° angular displacement of the main horizontal extent  75  to bring the main horizontal extent  75  generally parallel to the width of the seat  21 . In this position, the tray  91  is in position immediately in front of an individual which would otherwise be seated in the seat  21 . As is shown in  FIG. 4 , the width and depth of the tray  91  is advantageous for use as a writing surface or a food support function. 
         [0036]    If an individual sitting in the seat  21  were to lean or rest on the tray  91 , such resting is most likely to occur on either the edge of the tray  91  closest to the main horizontal extent  75  of the main tray bearing member  71 , or directly on the main horizontal extent  75  itself. Utilizing a support member for the tray  91  closest to the seated person helps to eliminate the need for reinforcement of the support of the tray  91  against inadvertent leaning weight on the tray  91  which would translate into bending moment if the tray  91  were not supported most immediately adjacent the line most closely adjacent an individual, if they were seated in the seat  21 . Also note in  FIG. 4  that the moveable locking clip  65  in  FIG. 4  is in locked position so that the tray system  55  will remain in a fixed position with respect to the seat  21  until altered by a user. 
         [0037]    The structures which control and fix the tray system  55  will next be examined in more detail. Referring to  FIG. 5 , a perspective closeup view looking down into the back side of one of the tray deployment fittings  81  inside of the tray system  55 . The rear side of the tray deployment fitting  81  has a generally open space having an uppermost bearing surface  101  which is seen closely adjacent main horizontal extent  75 . Seen at the underside of the main horizontal extent  75  is a limit block  103 . The tray deployment fitting  81  may rotate upon the main horizontal extent  75  but limited by the contact of the uppermost bearing surface  101  against the limit block  103 . As presented earlier, the rotational displacement possible of the tray deployment fitting  81  about the main horizontal extent  75 , from a position of vertical hanging as seen in  FIG. 5 , is expected to be an angle of about 130°. 
         [0038]      FIG. 6  is a perspective exploded view of the assembly seen in  FIG. 5  and illustrates that the limit block  103  may be preferably attached by a rivet  107  after the tray deployment fittings  81  is threaded onto the main horizontal extent  75  of the main tray bearing member  71 . The tray deployment fitting  81  is seen to have a pair of spaced apart apertures  111  through which the main horizontal extent  75  of the main tray bearing member  71  will be inserted. Once the tray deployment fitting is located along the main horizontal extent  75  of the main tray bearing member  71 , the limit block  103  and riveted with rivet  107  to the underside of the main horizontal extent  75 . This will axially fix the tray deployment fitting  81  with respect to the main horizontal extent  75 . 
         [0039]    Other structures visible in  FIG. 6  includes a pin aperture  115  seen through the support  85 . A pivot pin  117  will engage a pair of pivot pin bores  119  formed in the tray deployment fittings  81 . Bosses  121  are seen for insuring that the support  85  is centered within the tray deployment fitting  81 . Note that pivot pin bores  119  lie along an axis which is spaced apart from the axis of the pair of spaced apart apertures  111 . As discussed previously, the total angular displacement of the tray deployment fittings  81  as pivot stop structure is an angle of about 130° and the exterior pivot fitting angle between the supports  85  and contact with the exterior of the tray deployment fittings  81  of about 140° to produce a total angular displacement of about 270°.  FIG. 6  makes the double angular limitations more easily observable. 
         [0040]    Referring to  FIG. 7 , a view from the rear of the tray system support fitting  61  attached to the front vertical support  41  of the seat  21  is seen. Attachment member  63  is seen as having extended completely through the tray system support fitting  61  to the back side. The moveable locking clip  65  is seen as having a pair of attachment apertures  126  which engage pivot projections  129  which extend from a standoff support  131 . Standoff support  131  may be integrally formed with the tray system support fitting  61 . Note that the moveable locking clip  65  has a projection  135  which moved to apply force to the surface of the main vertical main extent  73  through an opening  139 . In the locked position, the moveable locking clip  65  prevents upward and downward movement, and imparts rotational resistance to the main tray bearing member  71 . Referring to  FIG. 8 , a partially exploded view illustrates further details of the components seen in  FIG. 7 . 
         [0041]      FIG. 9  is a sectional view taken along line  9 - 9  of  FIGS. 2 and 5  and showing the state of the internal and external pivot limiting components of the tray system  55 . The limit block  103  and rivet  107  are seen and show the starting point for pivoting action of the tray deployment fittings  81  with respect to the main horizontal extent  75 . 
         [0042]    Referring to  FIG. 10 , a sectional view as in  FIG. 9  shows the state of pivot limits. Tray deployment fitting  81  is seen to rotate to a position in which the uppermost bearing surface  101  bears against and is prevented from further rotation by limit block  103 . Further, the pivot action of the tray support  85  about the pivot pin  117  is limited by contact of the tray support  85  against the exterior of its associated tray deployment fitting  81 . As can be seen, the tray  91  is taken from a position which is generally vertical as shown in  FIG. 9  to a position which is horizontal as seen in  FIG. 10 . 
         [0043]    Referring to  FIG. 11 , a sectional view taken along line  11 - 11  of  FIGS. 4 and 7  and showing the tray system  55  gives a further illustrative view of the operation of the tray system support fitting  61  and its moveable locking clip  65 .  FIG. 11  shows the locked position also seen in  FIG. 4 . The moveable locking clip  65  is in a closed position bringing projection  135  into high friction compressive contact against the outer surface of the vertical main extent  73 . Referring to  FIG. 12 , a sectional view as seen in  FIG. 11  shows the tray system  55  in an unlocked position with the moveable locking clip  65  in an open position disengaging the projection  135  from friction contact with the exterior of the main vertical main extent  73  of the main tray bearing member  71 . 
         [0044]    The detailed description set forth below in connection with the appended drawings is intended as a description of presently preferred embodiments and is not intended to represent the only forms in which the present invention may be constructed and or utilized. While preferred embodiments of the invention have been shown and described, it is understood by those skilled in the art that changes and modifications may be made without departing from the spirit and scope of the invention.