Abstract:
A high chair features various modes of adjustability and enhanced utility. The height of the chair can be adjusted using a single hand that engages a rear handle. The height of a seat platform of the chair can be adjusted separately relative to the tray. The tray itself is ergonomically designed for the benefit of the caregiver. A removable tray liner facilitates after-meal clean-up. Wheels on the underside of the tray ease fore/aft adjustment. A pivoting back rest of the chair minimizes rearward shift of the center of gravity of the occupied chair, thus requiring a smaller chair footprint. Further, an accessory bar pivoted to a seat back portion of the chair provides readily accessible entertainment.

Description:
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS  
       [0001]     This application is a divisional of U.S. application Ser. No. 10/803,086, filed Mar. 18, 2004, which claims the benefit of U.S. Provisional Application Ser. No. 60/457,325, filed Mar. 26, 2003, both applications being incorporated by reference in their entireties. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The present invention relates to seating for children and, in particular, to high chairs.  
         [0003]     High chairs have been provided with a myriad of features designed to enhance their comfort, safety and convenience. There is room for improvement, however, as to several aspects of high chair design. This invention addresses these needs.  
         [0004]     During the course of attending to a child in a highchair, it is common practice for the caregiver to sit in front of the highchair and rest his or her arms on the high chair tray. High chair trays typically are made of a relatively hard, unforgiving material and do not provide a comfortable resting place for the caregiver&#39;s arms.  
         [0005]     The tray of a high chair can become extremely soiled by an infant while eating. Often relatively large food chunks remain on the surface of the tray. The effective and controlled removal of this debris is not adequately addressed in the prior art.  
         [0006]     The position of a high chair tray often requires adjustment. Often the tray sticks, or does not slide easily on the surface of the highchair on which it bears.  
         [0007]     High chairs that allow the height of the chair to be adjusted require the use of two hands to make the adjustment. Busy caregivers often find that only one hand is free for making a height adjustment. This requires the caregiver first to free up one hand before the adjustment can be made.  
         [0008]     Stringent stability (tipping) regulations have a direct impact on the footprint geometry of a high chair. Generally speaking, consumers prefer to have a high chair with a small footprint so that it can be integrated into the kitchen or table setting more conveniently. The footprint size, which is governed by stability concerns, is necessarily larger in high chairs that have a recline feature. Because a child&#39;s head comprises a significant proportion of his or her body weight, in reclining high chairs the center of gravity can move substantially to the rear as the child is moved from a full upright to a reclining position. Thus it is highly desirable to minimize the shift of the center of gravity when the seat back is reclined, whereby the footprint of the high chair can be minimized.  
         [0009]     Recline mechanisms that allow the seat back to pivot at the bight portion of the seat usually cause a change in the distance between the seat back and the crotch support of the armbar as the seat is moved through various recline positions. This distance is regulated by industry standards, and it is highly desirable to be able to vary the angle of the seat back without significantly altering the distance between the seat back and the crotch support.  
         [0010]     Children typically utilize high chairs throughout a relatively large age span. The wide range of physical development that a child undergoes during this time presents a formidable challenge to designing a high chair that ideally accommodates all of the physical needs of the child. This situation is exacerbated by high chairs that have recline features, enabling the unit to be used for very young infants, and removable arm bars, which when removed allow the chair to be pulled right up to a table for use by an older child. One aspect of available high chairs that does not adequately address this need is the seat height relative to the tray. Most high chairs are designed to accommodate the older child, which means that the tray is usually higher than optimal for an infant or a toddler.  
         [0011]     Finally, a consumer-preferred feature is to have entertainment value readily available for a child in a high chair. Often after a meal it is desirable to keep the child in the high chair and quickly occupy the child with interesting objects that cannot be thrown to the floor.  
       SUMMARY OF THE INVENTION  
       [0012]     One aspect of the invention concerns a chair tray that is configured ergonomically for the caregiver. The tray has a rim portion, for example, a front rim portion, with an undulate height profile. This height profile has a medial portion flanked by two rest portions that are lower than the medial portion. The rest portions can be flanked by two shoulder portions that are higher than the rest portions, and the rest portions can have curved upper surfaces and rounded upper edges.  
         [0013]     Another aspect of the invention concerns a removable insert for a tray that facilitates clean-up. The insert comprises a self-supporting, flexible member that is shaped generally to conform to and cover a central portion of the tray. The insert also may cover at least the immediately adjacent portions of a rim of the tray. The insert can include a central portion and a raised rim surrounding the central portion, and, in one embodiment, the raised rim can extend over and completely cover the rim of the tray. When removed from the tray, the insert can be flexed and tilted to channel food scraps to the center and one edge of the insert for easy disposal into a trash receptacle. The insert can be stably supported on any flat surface as a rimmed place mat when removed from the tray.  
         [0014]     Still another aspect of the invention facilitates easy fore/aft adjustment of the tray. The tray has a top side, an underside, and at least one wheel mounted to the underside to rotate for movably supporting the tray on a bearing surface of the chair. In one embodiment, the tray can have three wheels, two of which are laterally spaced and are rotatable about a common axis, and the third being centrally located and rotatable about an axis offset from the common axis. The chair can have an occupant restraint at the front of the seat, and the central wheel rides on a recessed track in the occupant restraint.  
         [0015]     A further aspect of the invention facilitates one-handed height adjustment of the chair. The chair comprises a seat including a seat bottom portion and a seat back portion, the seat bottom portion having a downwardly extending leg rest portion. A floor-engaging frame supports the seat, the frame including a front member in supporting engagement with the leg rest portion, the leg rest portion being slidable relative to the front member. The frame also includes an adjustable support for the rear of the seat comprising adjustably engageable mating portions of the frame and the seat. The chair also can have a handle for effecting the adjustment and for helping to bear the weight of the seat (and the occupant) with one hand as the adjustment is made.  
         [0016]     According to another aspect of the invention, the height-adjustable high chair comprises a seat, a floor-engaging frame including opposed side portions at opposite sides of the seat, and a height-adjustable support assembly between the seat and the frame. The support assembly can comprise a toothed rack on each side portion of the frame; a movable latch on the seat having a tooth at each side thereof for selectively engaging the teeth of the respective racks; and a handle for moving the latch between latched and unlatched positions. The handle can be centrally located. The latch can comprise a transverse bar pivoted transversely to the seat with a tooth at each of its ends, the handle being located on the bar for pivoting it between latched and unlatched positions.  
         [0017]     Yet another aspect of the invention minimizes the shift of the center of gravity of the chair/occupant combination. The chair comprises a seat including a seat bottom portion and a seat back portion pivotally mounted relative to the seat bottom portion about a transverse pivot axis to move between an upright position and a reclined position. The two seat portions define a seat bight region along the seat bottom portion between a first transverse axis, where a lower edge of the seat back portion intersects the seat bottom portion when the seat back is in the upright position, and a second transverse axis, where a lower edge of the seat back portion intersects the seat bottom portion when the seat back is in the reclined position. The pivot axis is located above and forwardly of the seat bight region. If such a chair has armrest portions, the seat back portion can be provided with lateral extensions that are pivoted to the armrest portions about the pivot axis. The seat bottom portion can be curved upwardly at the rear thereof, and the seat back portion can be similarly curved at the bottom thereof to slide closely past the seat bottom portion throughout the range of adjustment of the seat back portion.  
         [0018]     According to another aspect of the invention, the chair comprises a seat including a seat bottom portion and a seat back portion pivotally mounted relative to the seat bottom portion about a transverse pivot axis so that the seat back portion can move through a range of adjustment relative to the seat bottom portion. The seat back portion has a lower edge, and the lower edge overlaps the seat bottom portion. The pivot axis is located above and forwardly of the lower edge of the seat back portion throughout the range of adjustment.  
         [0019]     According to yet another aspect of the invention, the chair comprises a seat including a seat bottom portion having a seating surface and a seat back portion having a back support surface. The seat back portion is pivotally mounted relative to the seat bottom portion about a transverse pivot axis so that the seat back portion can move through a range of adjustment relative to the seat bottom portion. The pivot axis is located above the seating surface and forwardly of the back support surface throughout the range of adjustment.  
         [0020]     According to still another aspect of the invention, the chair comprises a seat including a seat bottom portion having a seating surface with a centerline and a seat back portion having a centerline. The seat back portion is pivotally mounted relative to the seat bottom portion about a transverse pivot axis so that the seat back portion can move through a range of adjustment relative to the seat bottom portion. The pivot axis is located above the portion of the seating surface along its centerline and forwardly of the portion of the seat back portion along its centerline.  
         [0021]     Another aspect of the invention provides for adjustability so that proper seat-to-tray distance can be achieved. The chair comprises a seat including a seat bottom portion and a seat back portion; a seat platform above the seat bottom portion; and an elevating mechanism beneath the seat platform for adjusting the height of the seat platform relative to the seat bottom portion. The seat platform and the elevating mechanism can be parts of an adjustable seat assembly that also comprises a base attached to the seat bottom portion, the elevating mechanism being located between the base and the seat platform. The elevating mechanism can comprise a movable elevating member supporting the seat platform, and a ramped surface on at least one of the elevating member, the base and the seat platform, whereby movement of the elevating member changes the height of the seat platform.  
         [0022]     A further aspect of the invention provides readily available entertainment for the high chair occupant. This entertainment is in the form of an accessory bar pivoted to the seat about a transverse axis, the accessory bar being movable between a forward position in which the bar is disposed in front of the seat back portion for access by the seat occupant, and a retracted position in which the bar is disposed above and/or behind the seat back portion. Toys or other items of interest can be attached to the bar. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0023]     The above and other features, aspects and advantages of the invention will become apparent from the following detailed description and the accompany exemplary embodiments shown in the drawing figures, in which:  
         [0024]      FIG. 1  is a top perspective view of a high chair according to the invention;  
         [0025]      FIG. 2  is a front perspective view of a tray according to the invention;  
         [0026]      FIG. 3  is a top perspective view of the tray of  FIG. 2 ;  
         [0027]      FIG. 4  is a front perspective view of a tray and a raised tray insert according to the invention;  
         [0028]      FIG. 5  is a front perspective view similar to  FIG. 4 , showing the tray insert in position on the tray;  
         [0029]      FIG. 6  is a bottom plan view of a tray according to the invention;  
         [0030]      FIG. 7  is a top plan view of a lower tray on which the tray of  FIG. 6  rests;  
         [0031]      FIG. 8  is a cross-sectional view of the tray taken along line  8 - 8  in  FIG. 6 ;  
         [0032]      FIG. 9  is a bottom perspective view of the chair of  FIG. 1 , showing a portion of the height adjustment mechanism according to the invention;  
         [0033]      FIG. 10  is a detail perspective view similar to  FIG. 9 , showing the height adjustment mechanism in the latched condition;  
         [0034]      FIG. 11  is a detail perspective view similar to  FIG. 10 , showing the height adjustment mechanism in the unlatched condition;  
         [0035]      FIG. 12  is a bottom perspective view of the leg rest portion of the chair of  FIG. 1  and the support for the leg rest portion;  
         [0036]      FIG. 13  is a perspective view of portions of the seat of the chair of  FIG. 1 ;  
         [0037]      FIG. 14  is a front elevational view of the backrest portion of the seat;  
         [0038]      FIG. 15  is a perspective view of an adjustable seat assembly according to the invention;  
         [0039]      FIG. 16  is an exploded view of the seat assembly of  FIG. 15 ;  
         [0040]      FIG. 17  is partial assembly/exploded view of the seat assembly of  FIG. 15 ;  
         [0041]      FIG. 18  is a side elevational view of another form of adjustable seat assembly according to the invention, shown in its lowest (collapsed) configuration;  
         [0042]      FIG. 19  is a view similar to  FIG. 18 , showing the seat assembly of  FIG. 18  in an elevated (expanded) configuration;  
         [0043]      FIG. 20  is a bottom perspective view of the seat assembly of  FIG. 18 ;  
         [0044]      FIG. 21  is a bottom perspective view of the seat assembly of  FIG. 18 , with the base removed;  
         [0045]      FIG. 22  is a perspective view of the accessory bar according to the invention, shown in the forward position; and  
         [0046]      FIG. 23  is a perspective view of the accessory bar of  FIG. 22 , shown in the raised position. 
     
    
       [0047]     It is to be understood that the invention is not limited in its application to the details of construction and the arrangement of components described below and illustrated in the drawing figures. Those skilled in the art will recognize that various modifications can be made without departing from the scope of the invention, which is defined by the appended claims.  
       DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0048]     Reference will now be made in detail to presently preferred embodiments of the invention, examples of which are illustrated in the accompanying drawings. An effort has been made to use the same reference numbers throughout the drawings to refer to the same or like parts.  
         [0049]      FIG. 1  generally shows a high chair  10  according to the invention, which comprises a floor-standing frame  20  supporting a seat  30 . A removable arm bar  40  on the seat supports a removable tray  50  (see  FIGS. 2, 6 ,  8 ).  
         [0050]     Frame  20  has an integrally molded plastic chassis  202  with spaced side portions  204  interconnected by a front cross member  206 . Chassis  202  also has fixed front leg sockets  208 , which receive tubular front legs  210 , and pivoting rear leg sockets  212 , which receive tubular rear legs  214 . Floor-engaging feet or casters (not shown) are provided at the bottom ends of legs  210 ,  214 . The pivoting nature of rear leg sockets  212  enables the rear legs  214  to be folded for more compact storage when the high chair is not in use.  
         [0051]     Seat  30  comprises a molded plastic seat bottom portion  310  adjustably supported on chassis  20 , and a molded plastic seat back portion  320  pivoted to seat bottom portion  310 . Seat bottom portion  310  has an integrally molded leg rest portion  312 , and integrally molded armrest portions  314 . Seat  30  is depicted as a bare shell, it being understood that a padded covering (not shown) would normally be used to enhance the comfort of the seat.  
         [0052]     Referring to  FIG. 7 , armrest portions  314  support the removable arm bar  40 . Arm bar  40  is molded of plastic, has various recesses  42 , and functions as a small tray. Arm bar  40  also has a depending crotch bar  44 , which functions as a restraint to prevent the child occupant from sliding out of the chair. Removable tray  50  is movably supported on the upper side surfaces  46  and a central recessed surface  48  of arm bar  40 , as described below.  
         [0000]     Tray Features  
         [0053]     The tray  50  can include at least one wheel mounted to its underside to rotate for movably supporting the tray  50  on a bearing surface of the chair. For example, referring to  FIGS. 6 and 8 , the underside of tray  50  can be provided with three wheels: two laterally spaced wheels  502 , which ride on side surfaces  46  of arm bar  40 , and a center wheel  504 , which rides on recessed track  48  of arm bar  40 . Each of the wheels is supported on an axle  506 , which is carried by webs  508  that are integrally molded into the tray. The wheels facilitate fore/aft adjustment of the tray. Tray  50  is retained on arm bar  40  by tabs  510  that engage the bottom side edges of arm bar  40 . Each tab  510  is carried by a side release handle  512 , which is pivoted at  514  to the underside of the tray. Side release handles  512  are connected to a central release button  516  at the front of the tray by a pair of flexible but rigid straps  518 , which are guided between webs  520  and can transmit force along their length. A spring (not shown) can be housed in release button  516  to bias the button outwardly and, through straps  518 , to bias the retaining tabs  510  inwardly to a locking position. To move the tray, the caregiver need only press the release button  516  inwardly (or squeeze handles  512  upwardly) to unlock retaining tabs  510 , whereupon the tray can be rolled fore or aft on wheels  502  to a new position and locked there.  
         [0054]     The front of the tray  50  is ergonomically contoured to enhance comfort for the caregiver. Referring to  FIGS. 2 and 3 , central portion  526  of tray  50  is surrounded by a raised rim  530 , and the front of the rim has an undulate height profile. Specifically, the medial portion  532  of the rim is higher than the two adjacent rest portions  534 , and the rest portions  534  are flanked by higher shoulder portions  536 . The rest portions  534  have gently curved upper surfaces and rounded upper edges. These features cradle the caregiver&#39;s hands or arms quite comfortably, as shown in  FIG. 3 .  
         [0055]     Further, as can be seen in  FIG. 2 , the central portion  526  of the tray  50  gently slopes upward to the upper edge of rim  530 . That is, the inner surface  538  of rim  530  is angled, rather than perpendicular, relative to central portion  526  and the upper edge of rim  530  to make wiping away of food scraps from the central portion  526  over rim  530  easier.  
         [0056]     Referring to  FIGS. 4 and 5 , tray cleaning after meals or other activities is facilitated by a removable flexible tray insert or liner  60  that fits onto tray  50 . Insert  60  is molded of a flexible plastic or rubberized material that is shaped generally to conform to and cover the central portion  526  of the tray. The insert  60  also can be shaped generally to conform to and cover at least the immediately adjacent portions of the rim  530  of the tray. The insert  60  includes a central (major) portion  604  to cover the central portion  526  of the tray  50  and a raised rim  606  surrounding the central portion  604 . The raised rim  606  can cover at least the immediately adjacent portions of the rim  530 . In one embodiment, as shown in  FIG. 5 , the raised rim  606  extends over and completely covers the rim  530  of the tray  50 . A convenience tab  602  facilitates removal of the insert. Insert  60  thus can readily be removed from tray  50 , carried to a trash receptacle, and flexed and tilted to channel food scraps or other debris to the center and one edge of the insert (as is commonly done, for example, with table place mats) for easy disposal of the debris. In addition, the insert  60  is flexible enough to fit, when folded, into a standard-sized homeowner&#39;s sink, which facilitates clean-up. The central portion  604  of insert  60  is substantially flat, such that the insert  60  can be stably supported on any flat surface, e.g., a table, as a rimmed place mat when removed from the tray. The insert  60  is can be made of a material that has a relatively high coefficient of friction so that it will not slip or slide easily on a table or other surface. The insert  60  can include a recess  608  to hold a beverage. The recess  608  can be received in a beverage recess  528  of the tray  50 . Additional recesses can be provided to enhance the versatility of the insert  60 .  
         [0000]     Chair Height Adjustment  
         [0057]      FIGS. 9-11  depict the features that enable one-handed adjustment of the height of the seat  30  relative to the frame  20 . The inboard face of each chassis side portion  204  has an integrally molded rack  220  with a series of vertically spaced teeth  222 . Each tooth  222  has a support shoulder or ledge  224  that is adapted to bear one half the weight of the seat. A rear bearing surface  226  and a shoulder  228  on chassis side portion  204  serve to guide and locate seat  30 .  
         [0058]     A transverse bar  350  is pivoted about its longitudinal axis  352  to the bottom rear of seat  30  in a U-shaped recess  354  at each side of the seat. A retaining tab  356  at each side helps to keep bar  350  in position in recesses  354 , while allowing the bar  350  to pivot. A tooth  360  at each end of bar  350  engages the shoulder  224  of a selected tooth  222  in its respective rack  220 . A leaf spring  357  biases transverse bar  350  to the latched position, i.e., the position in which teeth  360  engage teeth  222  (see  FIG. 10 ). A central handle  358  is integral with transverse bar  350 . Handle  358  has a grip portion  358   a  adapted to be grasped by the fingers of a hand, and a heel portion  358   b  adapted to be engaged by the heel of the hand when the fingers engage grip portion  358   a . A curved extension  362  at each side of seat  30  wraps around the respective chassis side portion  204 . The extension  362  has a bearing surface  366  and a shoulder  368  that mate with bearing surface  226  and shoulder  228 , respectively.  
         [0059]     To change the height of seat  30 , central handle  358  is grasped by a single hand, with the fingers wrapped around grip portion  358   a  and the heel of the hand engaging heel portion  358   b . Heel portion  358   b  is then raised, which pivots transverse bar  350  in the direction of the arrows in  FIGS. 10 and 11  to move teeth  360  out of engagement with teeth  222  (see  FIG. 11 ). Substantially the entire weight of the seat (and the seat occupant) can be borne by the fingers that engage the grip portion  358   a  of handle  358 , whereby the seat can be raised or lowered by one hand to a new position. When the new position is reached, handle  358  is released, which allows bar  350  to pivot back to the latched position with teeth  360  in engagement with new teeth  222 . The mating bearing surfaces  226 ,  366  help to resist downward tilting of seat  30 . Additional stability for seat  30  is provided by chassis front cross member  206  (see  FIG. 12 ), which has guiding support slots  207  that slidably engage support flanges  313  on leg rest portion  312 . The dashed lines in  FIG. 12  illustrate how the leg rest portion  312  moves relative to the front cross member  206 .  
         [0000]     Recline Features  
         [0060]      FIGS. 13 and 14  depict the recline features of the high chair. The seat back portion  320  is pivotally mounted to the seat bottom portion  310  about a transverse pivot axis, for example, axis  322 , to move between an upright position (as shown in  FIG. 14 ) and a reclined position. The seat back portion  320  and seat bottom portion  310  together define a seat bight region, generally indicated  316 , along the seat bottom portion  320 . The seat bight region  316  is defined as the region between a first transverse axis A 1  of the seat bottom portion  310 , where a lower edge  323  of the seat back portion  320  intersects the seat bottom portion  310  when the seat back is in the upright position, and a second transverse axis A 2  of the seat bottom portion  310 , where the lower edge  323  intersects the seat bottom portion  310  when the seat back is the reclined position. The pivot axis  322  is located above and forwardly of this seat bight region, as can be seen in  FIGS. 1 and 13 . According to another aspect of the invention, the pivot axis  322  is located above and forwardly of the lower edge  323  of the seat back portion  320  throughout the range of adjustment of the seat back portion  320 .  
         [0061]     Seat back portion  320  has integrally molded lateral tabs or extensions  321  that extend forwardly and are pivoted to armrest portions  314  about the pivot axis  322 . As compared to a conventional arrangement in which the seat back is hinged to the seat bottom in the seat bight region, the geometry of chair  10  substantially lessens the rearward excursion of the seat back portion  320  when reclined. This minimizes the rearward shift of the center of gravity of the occupied high chair, whereby the high chair can meet stability requirements with a smaller footprint. The rear portion of seat bottom portion  310  is curved upwardly, in the seat bight region  316 , and the bottom  324  of seat back portion  320  is similarly curved so as to slide closely past the seat bottom portion  310  throughout the range of adjustment of the seat back portion  320 .  
         [0062]     The seat back portion  320  can be selectively locked in various positions. This is facilitated by a series of notches  318  near each side of the seat bight portion  316  of seat bottom portion  310 . The notches  318  are engaged by retractable bolts  326   a ,  326   b  carried by seat back portion  320 . These bolts  326   a ,  326   b  are essentially the ends of guided flexible, but rigid, straps  328   a ,  328   b , similar to those used on the underside of tray  50  (see  FIG. 6 ). The straps  328   a ,  328   b  are connected to a central release button or handle  330  at the top of seat back portion  320  through a central strap  329 , which is bifurcated and laterally directed at its bottom to engage straps  328   a ,  328   b . As seen in  FIG. 14 , bolts  326   a ,  328   b  are biased into engagement with notches  318  under the influence of a coil spring  332 , which acts on straps  328   a ,  328   b  indirectly through central strap  329 . Downward pressure on release button  330  moves central strap  329  downwardly against the action of spring  332 . This downward movement is translated into a lateral pulling movement of straps  328   a ,  328   b  as indicated by the arrows in  FIG. 13 , whereby the bolts  326   a ,  326   b  are retracted from the notches  318 . A stop  334  associated with release button  330  engages a window edge  336  in seat back portion  320  to limit upward movement of the release button.  
         [0063]     The seat bottom portion  310  has a seating surface  310 S upon which a child sits, and the seat back portion  320  has a back support surface  320 S against which a child can lean its back. According to another further of the invention, the pivot axis  322  is located above the seating surface  310 S and forwardly of the back support surface  320 S throughout the range of adjustment of the seat back portion  320 . The seating surface  310 S can have a centerline (not shown) that bisects the seat bottom portion  310  into left and right halves and that extends from a front edge of the seat bottom portion  310  to the front edge of the seat bight region  316 . Likewise, the back support portion  320  can have a centerline (not shown) that bisects the back support portion  320  into left and right halves. According to yet another aspect of the invention, the pivot axis  322  is located above the portion of the seating surface  320 S along its centerline and forwardly of the portion of the seat back portion  310  along its centerline.  
         [0064]     As can be seen from  FIG. 13 , the angle of the seat back portion  320  relative to the seat bottom portion  310  varies, as the seat back portion  320  moves between the upright position and the reclined position, throughout its range of adjustment. Yet the distance between the seat back portion and the crotch support is not significantly altered.  
         [0000]     Seat-to-Tray Height Adjustment  
         [0065]      FIGS. 15-17  depict a first embodiment  70  of an adjustable seat assembly that is adapted to support the chair occupant at a selected height relative to the tray. As best seen in  FIG. 16 , seat assembly  70  comprises three main components: a base  710  adapted to rest on seat bottom portion  310 ; a seat platform  730  adapted to overlie base  710  and support the occupant; and an intermediate elevating mechanism  740  for adjusting the height of the seat platform relative to the base. These components can be made of injection molded plastic material. Base  710  is upwardly dished and has a central opening  712  that accommodates crotch bar  44  (see  FIGS. 1 and 7 ) and a webbed crotch restraint, if so equipped. Seat platform  730  also has a crotch bar hole  732  that serves the same purpose. Side studs  714  on base  710  extend through side holes  734  in seat platform  730  to keep the parts from separating, and the studs  714  can be used to secure the seat assembly to the seat bottom portion  310  by suitable means (not shown). A front notch  718  is aligned with a central recess  720 , and both of these structures cooperate with a portion of the elevating mechanism  740 , as described below. A plurality of wedges  722  have ramped surfaces  724  over which a portion of the elevating mechanism rides. The elevating mechanism is guided in two parallel notches  716  in base  710 .  
         [0066]     Elevating mechanism  740  comprises a frame  742  surrounding a large central aperture  744  (through which crotch bar  44  can pass). At the front of frame  742  is a threaded hole  746  flanked by guide feet  747 . A shaft  748  has a threaded portion  750  that engages threaded hole  746 , with the rear end  752  of shaft  748  captured in recess  720 . The shaft  748  also has a groove  754  captured in the front notch  718  of base  710 . A knob  756  at the front end of shaft  748  facilitates rotation of shaft  748 , which moves frame  742  fore or aft. At the rear of frame  742  is a bar  760  with lower surfaces  762 , which ride on ramps  724 , and upper surfaces  764 , which support seat platform  730 . Thus, as knob  756  is turned, frame  742  and bar  760  move fore or aft over wedges  722  to change the height of seat platform  730 .  
         [0067]     A second adjustable seat assembly embodiment  80  is shown in  FIGS. 18-21 . The embodiment  80  also comprises a base  810 , a seat platform  830 , and an adjusting mechanism  840 . In this embodiment, the element that moves fore and aft to adjust seat platform height is a U-shaped slide  844  (see  FIG. 21 ) that has wedges  845 . Crotch bar holes  812 ,  842  are provided, as in the first embodiment. Slide  844  has a front cross member  846  with a slot  848 . A wheel  850  is centrally pivoted to the underside of seat platform  830 , and has an eccentric pin  852  that resides in slot  848 . Rotation of wheel  850  moves pin  852  which moves slide  844  with its wedges fore or aft, thus causing the height of seat platform  830  to change.  
         [0000]     Accessory Bar  
         [0068]      FIGS. 22 and 23  depict a U-shaped accessory bar  90  and its use. Accessory bar  90  can be made of plastic or other suitable stiff and lightweight material. Accessory bar  90  is shown covered by a soft sleeve  902  and supporting a number of toys  904 . The ends  906  of bar  90  are pivoted to the seat, for example, to the seat back portion  320  as shown, about a transverse axis. Any suitable pivots may be used. Each pivot can have two stops that limit movement of the bar  90 . The first stop keeps the bar from dropping onto the tray  50  when the bar is in the forward (use) position ( FIG. 22 ). The second stop keeps the bar from dropping rearwardly below the upright (inactive) position ( FIG. 23 ). Thus, the accessory bar with its toys or other appendages can be quickly swung down in front of the seat occupant, or quickly moved out of the way to the upright position. In addition, the pivot connection of the bar  90  to the seat back portion  320  can be a break-away connection so that, if the bar  90  inadvertently is pivoted rearwardly past the second pivot, a predetermined force on the bar  90  (for example, a force applied by a curious child attempting to hang on, or step on, the bar  90 ) allows the bar  90  to break-away from the seat back portion  320 . In this manner, the high chair  10  will not be pulled over, rearwardly, if such force is applied to the bar  90 .  
         [0069]     The preferred embodiments have been set forth herein for the purpose of illustration. This description, however, should not be deemed to be a limitation on the scope of the invention. Various modifications, adaptations, and alternatives may occur to one skilled in the art without departing from the claimed inventive concept. The true scope and spirit of the invention are indicated by the following claims.