Abstract:
A table that is stowable and deployable from a seatback of a passenger seat includes a substantially planar food tray with a first surface and a second surface substantially parallel to the first surface. The tray is stowed in a substantially vertical position with the first surface facing a seated passenger. The stowed tray is held in position with a moveable switch engaged against the first surface. A device for stowing and deploying the tray is mounted on the second surface. A pair of legs is mounted to the device. Each leg has a first end attached to the device and a second end attached to the seat. Upon turning the switch clear of the first surface, the device slidably urges the first surface from its stowed position to a deployed, substantially horizontal position, with the first surface facing upwards.

Description:
FIELD OF THE INVENTION 
     This invention relates generally to embodiments of a passenger seat food tray. 
     BACKGROUND OF THE INVENTION 
     Existing food trays for airplanes are stowed in a recess of a seatback of an airplane. When stowed, a top surface of the tray faces inwardly toward the seatback. Thus, the top surface of the tray is inaccessible to airline personnel who clean airplanes. To clean a tray, airline personnel must unhinge the tray, lower the tray, clean the tray, and re-stow the tray. This cycle of unhinging, lowering, cleaning, and re-stowing each tray decreases efficiency of an airplane cleaning operation. These inefficient cleaning operations cost airlines time and money when turning an airplane around for receiving a next set of passengers. 
     Thus, there is an unmet need in the art for a food tray that can be rapidly wiped down and cleaned while the tray is stowed, thereby avoiding unnecessary steps and lost time spent unhinging and lowering the food tray for cleaning and re-stowing the food tray after it has been cleaned. 
     SUMMARY OF THE INVENTION 
     According to an aspect of the invention, a table is stowable and deployable from a seatback of a passenger seat. The table includes a substantially planar food tray with a first surface and a second surface substantially parallel to the first surface. The tray is stowed in the seatback in a substantially vertical position with the first surface facing outward towards a seated passenger, thereby permitting easy access cleaning of the first surface while in the stowed position. The vertically stowed tray is held in position with a moveable switch engaged against the first surface. A positioning means is mounted on the second surface which operates in stowing and deploying the tray. A pair of legs is attached to the positioning means, each leg having a first attached to the positioning means, and a second end attached to the seat. Upon turning the moveable switch clear of the first surface, the positioning means slidably urges the first surface from its stowed, substantially vertical position, to a deployed, substantially horizontal position, with the first surface facing upwards. 
     According to another aspect of the invention, a table is fitted with a means for rapidly detaching the tray for maintenance or replacement. A table is stowable and deployable from a seatback of a passenger seat. The table includes a substantially planar food tray with a first surface and a second surface substantially parallel to the first surface. The tray is stowed in the seatback in a substantially vertical position with the first surface facing outward towards a seated passenger, thereby permitting easy access for cleaning the first surface while in the stowed position. The vertically stowed tray is held in position with a moveable switch engaged against the first surface. A positioning means which operates in stowing and deploying the tray is mounted on the second surface. A pair of legs to the positioning means is attached a pair of legs, each leg having a first end attached to the positioning means, and a second end attached to the seat. Upon turning the moveable switch clear of the first surface, the positioning means slidably urges the first surface from its stowed, substantially vertical position, to a deployed, substantially horizontal position, with the first surface facing upwards. The means to rapidly detach the tray for maintenance or replacement includes a quick release mechanism that detaches the tray from and reattaches the tray to the pair of legs. 
     According to another aspect of the invention a table is substantially unaffected by seatback tilting caused by a forward seated passenger. A table is stowable and deployable from the seatback of the passenger seat. The table includes a substantially planar food tray with a first surface and a second surface substantially parallel to the first surface. The tray is stowed in the seatback in a substantially vertical position with the first surface facing outward towards a seated passenger, thereby permitting easy access for cleaning the first surface while in the stowed position. The vertically stowed tray is held in position with a moveable switch engaged against the first surface. To the second surface is mounted a positioning means which operates in stowing and deploying the tray. A positioning means which operates in stowing and deploying the tray is mounted on the second surface. A pair of legs, each leg having a first end attached to the positioning means, and a second end attached to a stationary region of the seat, is attached to the positioning means. Upon turning the moveable switch clear of the first surface, the positioning means slidably urges the first surface from its stowed, substantially vertical position to a deployed, substantially horizontal position, with the first surface facing upwards. The deployed, substantially horizontal position is substantially unaffected by tilting caused by the forward seated passenger. A means for rapidly detaching the tray for maintenance or replacement is provided, and includes a quick release mechanism. The quick release mechanism detaches the tray from and reattaches the tray to the pair of legs. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The preferred and alternative embodiments of the invention are described in detail below with reference to the following drawings. 
     FIG. 1 is the invention in a stowed position of a seat back wherein the food-serving surface is facing outward; 
     FIG. 2 is the invention in a deployed position; 
     FIG. 3 is the inner working mechanisms of the invention; 
     FIG. 4A is a side view of the planetary transport mechanism moving the invention between a stowed position to a deployed position; 
     FIG. 4B is an angled view of the timing belt and gearing mechanism; 
     FIG. 5 is an expanded view of the timing belt components of the invention; 
     FIG. 6A depicts the cable and spring mechanism during invention deployment; and 
     FIG. 6B shows the cable and spring mechanism during invention stowage. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     A tray  14  is shown in FIG. 1. A food-serving surface  17  of the tray  14  faces outward when vertically stowed in the recess of a seatback in seat  10 . A toggle  11  is turned upwards in an engaged position against latch  16 . Beneath the food-serving surface  17  resides a housing panel  15  that contains the mechanical components and assemblies of a positioning mechanism that deploys and stows the tray. The housing panel  15  is attached to tray legs  13  which are held in position to seat  10  via pivot pins  12 . 
     The tray  14  in a deployed position is shown in FIG.  2 . After the food service tray toggle  11  is rotated clear of the latch  16 , the tray  14  migrates in an incrementally sliding motion to a substantially level position toward a passenger&#39;s lap. The incremental sliding motion is achieved with the positioning mechanism (not shown) located within the housing panel  15 . The incremental sliding motion occurs about the tray legs  13  that are connected to the seat  10  via the pivot pins  12  mounted through a hole (not shown) in each tray leg  13 . 
     FIG. 3 is an exploded view that shows the interior view of the housing panel  15  removed from the bottom of tray  14 . The structural relationship of the toggle  11  is shown in relation to a side underneath the latch  16 . Several of the components visible in the positioning mechanism include two timing belts  43  located on each underside of tray  14 . Each timing belt  43  meshes with a fixed timing pulley  41  that is secured to tray leg  13 , and then meshes with a planetary timing pulley  42 . Planetary timing pulleys are rotationally connected to wrist sheave  64  and tray slide arm  68 . The spring (not shown) and cable components (not shown) interact with arm  51 . A shaft (not shown) of pulley  41  and an axle (not shown) of pulley  42  are engaged with elbow pivot (not shown) and wrist pivot (not shown), respectively, of arm  51 . The engagement of the shaft and axles of pulleys  41  and  42  with elbow and wrist pivots of arm  51  maintains a constant inter-pulley distance between pulleys  41  and  42 . A hole  30  is shown in tray leg  13  in which the pivot pins (not shown) are mounted. 
     Incremental sliding motion imparted by the positioning mechanism is depicted in FIGS. 4A and 4B. Referring to FIG. 4A, fixed timing pulley  41  keeps timing belt  43  fixed, and, together with arm  51  (not shown), establishes planetary pulley  42  to maintain a substantially constant inter-pulley distance from timing pulley  41 . As toggle  11  turns clear of its latch, tray  14  is gravitationally urged downward and causes timing belt  43  to partially wrap around timing pulley  41 , thereby changing the pivot point of timing belt  43 . Planetary pulley  42  is then gravitationally urged downward from the changing pivot point, but a substantially constant inter-pulley distance is maintained. Thus, planetary pulley  42  rotates around the fixed timing pulley and fixed timing belt  43 , but from a changing pivot point. The wrapping movement of timing belt  43  is transmitted to the fixed pulley  41  and the planetary pulley  42 , wherein meshing of each pulley&#39;s teeth with the belt&#39;s slots imparts an incremental sliding motion to the sliding tray  14  as it is urged gravitationally downward. This in turn causes a ratcheting action of the planetary timing pulley  42  as timing pulley  42  migrates within the fixed loop path of timing belt  43 . The resultant action is the transit of the tray  14  from a substantially vertical position to a substantially horizontal position as indicated in the angle depictions, and is determined by the gearing ratios of timing pulley  41  and planetary pulley  43 . The end of the horizontal transit is controlled by a fitting  59 , such as a stop pin, that is attached to the fixed timing pulley  41  as tray  14  pivots towards a horizontal position about tray leg  13 . When downward travel of tray  14  stops, the food serving surface  17  of tray  14  is in a substantially horizontal position and faces upwardly. 
     Other components of the positioning mechanism are shown in FIG.  4 B. Timing pulley  41  is attached to tray legs  13 . Timing belt  43  wraps about fixed timing pulley  41  with the fitting  59 . The timing belt, in turn, causes the planetary timing pulley  42  to rotate. The rotation of the planetary timing pulley  42  is transmitted to a planetary axle  69 . Axle  69  has a plurality of stepped, smooth surfaces and a splined end. The splined end of axle  69  meshes with a wrist spline hole  72  of tray slide arm  68 . Rotation of the axle  69  results in the circular rotation of tray slide arm  68  from an approximately 0 degree parallel position to the timing belt  43  (wherein the end of tray arm  68  is substantially even with fixed pulley  41 ) to an approximately 180 degree parallel position to timing belt  43  (wherein the end of tray arm  68  is located in a linear configuration with pulley  42  and pulley  41 ). As the rotation of tray slide arm  68  occurs about timing belt  43 , arm  68  migrates from a substantially vertical position to a substantially horizontal position in relation to the upper end of tray arm  13 . The angle that results between the deployed position and the stowed position is determined by the gearing ratio between the fixed turning pulley  41  and the planetary timing pulley  42 . 
     FIG. 5 shows in greater detail the positioning mechanism. The fixed pulley  41  and the planetary timing pulley  42  are shown in relation to arm  51  that is mounted to the underside of tray  14  via bolts placed through arm mounting holes  54 . Fixed timing pulley  41  has a double-D shaft  56  that is inserted through elbow pivot  52 , then to a cam-shaped fixed sheave  58  having a shaft aperture  57 , followed by washer  76 , which are all secured via bolt  77 . The fitting  59  of pulley  41  runs in the track provided by cutout  75  in arm  51 . The fitting  59  migrates between a lower extreme edge  90  and an upper extreme edge  92  of cutout  75 . Tray level adjust bolt  55  adjusts the lap-level placement of the tray  14 . 
     Inserted into wrist spline hole  72  is the splined end of axle  69  that is attached to planetary timing pulley  42 . The internal multi-stepped smooth surfaces of axle  69  mesh with the sliding surfaces of bushings in wrist pivot  53  and cable sheave  64 . The planetary timing pulley  42  has an external flip groove  70  that aids in its engagement with wrist pivot  53 . The multi-stepped smooth surfaces of axle  69  provide matches with the smooth surfaces provided by the bushings of wrist pivot  53  and wrist sheave  64  of arm  51 . The multi-stepped surface of the axle  69  meshes with the wrist sheave bushing  64 , then to the wrist splines  72  of tray slide arm  68 . The planetary timing pulley assembly is then secured to tray slide arm  68  with a washer  80  and C-clip  71 . 
     Tray slide arm  68  contains a tray slide arm end  66  upon which a spring anchor pin fitting  67  is attached. Fitting  67  is connected to a spring  65  that in turn is connected to a draw cable  61  via cable loop  62 . The draw cable  61  is routed over the outer groove of wrist sheave  64 , thence back to fitting  59  that is attached via cable attachment catch  60 . Cable slide fitting  63  is able to migrate along cable  61 . Tray slide arm  68  is mounted in a tray slot  74  located beneath tray  14 . Attached to the tray slot  74  is a tray draw fitting  73  attached. Fitting  73  engages with the moveable cable slide fitting  63  as the cable and spring are subjected to decreasing tension as the tray  14  is deployed or increasing tension during use and storing of tray  14 . 
     When tray  14  is in a stowed position, the spring  65  is stretched more than when tray  14  is in a deployed position. When tray  14  is deployed, the incremental sliding motion results in rotation of the fixed timing pulley  41  within confines imposed by cutout  75  of arm  51 . Arm  51 &#39;s rotary movement is limited by fitting  59  that limits pivotal motion to the extreme edges of cutout  75  of arm  51 . During deployment of the tray  14 , arm  51 &#39;s lower rotation movement is limited as edge  90  meets fitting  59 . During stowage of the tray  14 , arm  51 &#39;s upper rotation movement is limited as edge  92  meets fitting  59 . 
     Referring to FIG. 6A, tray  14  deployment causes cutout  75  to migrate about fitting  59  as tensile forces are exerted through draw cable  61 , thence to cable attachment catch  60 . This results in cable slackening as cable  61  unwraps from sheave  58 . Cable slackening is then transmitted around wrist sheave  64  to spring  65 . Spring  65  is depicted in a lightly stretched state as cable slide fitting  63  is caught between draw fitting  73  and cable loop  62 . A light spring tension is sufficient to keep cable slide fitting  63  captured within draw fitting  73  and to stretch the spring lightly as the cable  61  pulls from spring anchor  67  of tray slide arm  68 . 
     In contrast to deployment of the tray  14 , stowage of the tray  14 , as depicted in FIG. 6B, results in a maximally tensioned spring as tray slide arm  68  pivots away from draw fitting  73  mounted to the underside of tray  14 . Spring  65  is depicted in a highly stretched state as cable slide fitting  63  is caught between draw fitting  73  and cable loop  62 . Pushing of tray  14  in a more forward position results in an increased distance between the cable sheave  64  and the double D shaft  56  that is inserted into the aperture  57  depicted in the foreground of arm  51  shown in phantom. The spring  65  is stretched more between draw fitting  73 , which has captured tray slide fitting  63 , and spring anchor  67 . 
     When a passenger moves the tray  14  forward for stowage, the spring  65  is subjected to increased tension. Cam  58  and arm  51  co-rotate within aperture  57  about pin  59  and double D shaft  56  of the fixed timing pulley  41 , limited to the edge  92 . More of the circumference cam engages the sheave  58  through aperture  57 . Simultaneously, both sheave  58  and arm  51  co-rotate clockwise about pin  59  inserted through cable attachment catch  60 . More of the sheave&#39;s curved path is committed to the draw cable  61 . Increased tension of draw cable  61  results and is transmitted around wrist sheave  64 , then to the cable slide fitting  63 . Clockwise tensioning rotation is limited to the upper cutout edge  92 . Spring  65  is depicted in a more stretched condition for the stowed tray  14 . 
     While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. For example, the tray  14  may be readily detachable and reattachable to tray legs  13  via a quick release device. The quick release device may be a snap insert fitting, a bayonet breech fitting, a lever release fitting, or any equivalently functional quick release mechanism. 
     In another alternate embodiment, tray  14 , though deployed from a moveable seatback, suitably includes tray legs  13  that are attached to a stationary section of the seat. Such a configuration matches the deployed food tray not susceptible to tilting that occurs when a seat in front of the passenger is reclined. 
     Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiments. Instead, the invention should be determined entirely by reference to the claims that follow.