Patent Publication Number: US-6334652-B1

Title: Seat with adjustable backrest

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates to a seat and more particularly to an infant seat with angle adjustable backrest having the characteristics of simple components and convenient manipulation. 
     2. Related Art 
     Conventionally, an infant stroller is designed to provide a convenient transportability for parents in taking an infant out. Also, a highchair is designed to provide a convenient means to feed a baby by parents. Further, a swing is designed to provide an amusement to seated baby. In all above products, a seat for supporting infant is an indispensable component. In general, such seat comprises a seat portion and a backrest. 
     Further, typical seats are divided into seats with fixed backrest and seats with adjustable backrest. As to fixed backrest, seat portion and backrest are generally formed integrally such as by injection molding, or alternatively seat portion and backrest are separate pieces secured together by fasteners (e-g., screws, rivets). But an adjustable backrest is preferred for providing some degree of comfort to the seated person. A number of prior art mechanisms for adjusting backrest are found in a search such as Taiwanese Patent Publication Nos. 318,358 and 329,129 and U.S. Pat. No. 5,669,664. These prior art generally disclose a mechanism consisting a number of elements for adjusting the angle of backrest with respect to seat portion. For example, in above Taiwanese Patent Publication No. 318,358 and U.S. Pat. No. 5,669,664 both disclose the following characteristics: A plurality of notches are provided in each adjustable arm. The frame of adjustable arm is made of metal for enhancing the strength. Both adjustable arms are required to align precisely for effecting a cooperation each other. A positioning lever is releasably secured to one notch of either arm. Further, a control means provided in either seat portion or backrest is coupled to adjustable arm. Such control means is suitably located for providing a convenient manipulation of the angle adjustment of backrest for operator. 
     In view of above, adjustable arms, positioning levers, control means, and other associated elements are provided in such mechanism. Inevitably, it complicates the assembly procedure due to complex structure, resulting in an increase in the manufacturing cost. To the worse, its manipulation is not convenient. 
     Thus, it is desirable to provide an improved seat with adjustable backrest in order to overcome the above drawbacks of prior art. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a seat with adjustable backrest. The seat consists of a seat portion and a backrest for supporting infant. The above and other objects of the present invention are realized by configuring a plurality of notches on the arm of seat portion and two shaped shrouds of backrest each covered on the arm, whereby raising the shrouds will cause the shrouds to disengage from the notches so as to freely move above along the notches and release of the shrouds will cause the shrouds to move downward to engage with the notches. By utilizing this, an angle adjustment of backrest with respect to seat portion is effected. 
     Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will become fully understood from the detailed description given hereinbelow illustration only, and thus are not limitative of the present invention, and wherein: 
     FIG. 1 is an exploded view of a seat incorporating an angle adjustable mechanism according to the invention; 
     FIG. 2 is a perspective view of the assembled FIG. 1 seat; 
     FIGS. 3A,  3 B, and  3 C schematically depict operations of the FIG. 1 seat; 
     FIG. 4 is a perspective view of a highchair incorporating the angle adjustable mechanism according to the invention; and 
     FIG. 5 is a perspective view of a swing incorporating the angle adjustable mechanism according to the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1 and 2, there is shown a seat  10  consisting of seat portion  11  and backrest  12  incorporating an angle adjustable mechanism according to the invention. Seat portion  11  has a U cross-section to form a receiving space  111  for supporting an infant. Preferably, a soft fabric is covered on seat portion  11 . Seat portion  11  further comprises two arms  112 ,  113  and two side longitudinal slots  1121 ,  1131  below arms  112 ,  113  near the bottom wherein longitudinal slot  1121  has a top position  1123  and a bottom position  1122 . Note that since arm  113  is a mirror image of arm  112  such that a following detailed description of arm  112  is sufficient. Top surface of arm  112  is an arc with respect to the top position  1123  thereof. A plurality of notches  1124  is serially provided on the arm  112 . As such, one notch  1124  has an angle with respect to the vertical line passing the top position  1123  different from that of the adjacent notch  1124 . 
     Backrest  12  is movably attached to the rear of seat portion  11 . Backrest  12  comprises two shaped shrouds  121 ,  122 . Further, note that since shroud  122  is a mirror image of shroud  121  such that a following detailed description of shroud  121  is sufficient. Shroud  121  generally has an inverted U cross-section so as to cover on the arm  112 . Shroud  121  comprises a projection  1211  on the underside sized to match notch  1124  and an outward extended stud  123  sized to slidably move within the longitudinal slot  1121 . 
     In assembling adjust, simply put projections  1211  of shrouds  121 ,  122  onto predetermined notch  1124  of arm  112  and notch  1134  of arm  113  respectively. Then insert studs  123 ,  124  into longitudinal slots  1121 ,  1131  respectively. Thus, a complete seat  10  is assembled. 
     Referring to FIGS. 3A,  3 B, and  3 C, a detailed description of operations of the FIG. 2 seat  10  is as below. 
     In adjusting the relative positioning of backrest  11  with respect to seat portion  12 , first in a locked position (FIG. 3A) raising the shrouds  121 ,  122  of seat  12  will cause the shrouds  121 ,  122  to disengage from the notch  1124  of arm  112  and notch  1134  of arm  113  respectively (i.e., studs  123 ,  124  changed from bottom position  1122  of FIG. 3A to top position  1123  of FIG.  3 B). In this operating position (FIG.  3 B), then freely move shrouds  121 ,  122  above along the notches  1124 ,  1134  until a desired angle of the backrest  11  is reached (i.e., projections  1211  aligned with that desired notches  1124 ,  1134 ). Next release the shrouds  121 ,  122  to cause projections  1211  to move downward to engage with the other notches  1124 ,  1134  of arms  112 ,  113  respectively to lock the backrest  11  to the seat portion  12  again (i.e., studs  123 ,  124  changed from top position  1123  of FIG. 3B to bottom position  1122  of FIG.  3 C). As a result, an angle adjustable of backrest  11  with respect to seat portion  12  is effected. 
     Referring to FIG. 4, there is shown an application of the mechanism of the invention on a highchair. As shown, seat  10  is mounted on a frame  20  for supporting infant. Frame  20  comprises a plurality of coupled tube members  201  to form an elevation for the seat  10 . 
     Referring to FIG. 5, there is shown another application of the mechanism of the invention on a swing. As shown, seat  10  is mounted on a frame  20 ′ for supporting infant. Frame  20 ′ comprises a plurality of coupled tube members  201 ′, two opposed uprights  202 ′, and two brackets  203 ′. Each of the brackets  203 ′ has one end pivotally coupled to the top end of the uprights  202 ′ and the other end coupled to seat  10  so as to provide an amusement to the seated baby. 
     The invention being thus described, it will be obvious that the same may be varied in many ways. Such variations are not to be regarded as a departure from the spirit and scope of the invention, and all such modifications as would be obvious to one skilled in the art are intended to be included within the scope of the following claims.