Abstract:
A locking mechanism for a swivel seat of a baby walker is provided. The locking mechanism has a lock member which may be configured in a retained, free, or locked state with respect to the seat. When an infant rotates the seat to one of predetermined positions, the baby walker is locked so as to facilitate the feeding or playing of the infant.

Description:
BACKGROUND OF THE INVENTION 
     1. Field of Invention 
     The present invention relates to baby walkers and more particularly to a mechanism for locking swivel seat of baby walker in one of predetermined positions for facilitating the feeding by parent or the playing of infant. 
     2. Related Art 
     It is well known that baby walker is an exerciser for training an infant to walk. It is also understood that infant seated on baby walker may arbitrarily move to front, rear, left, or right. That is, the movement of baby walker is random and unpredictable. This may increase danger of the seated infant. A conventional baby walker comprises a seat for supporting the weight of infant, a circular frame (integrally formed with a tray), a stationary base, a plurality of legs intercoupled the base and the frame and support the seat, and a plurality of (e.g., four or six) wheels rotatably mounted under the base. Conventionally, wheels are caster wheels. Further, there is no locking mechanism provided in the baby walker. This is not safe in view of above. Hence, it is often recommended by manufacturers that parent or guardian should take great attention to the infant seated on baby walker. In fact, it is not unusual that accident may happen despite the attention being taken. 
     Of course, there is some baby walkers aimed at eliminating above drawback. And an improved baby walker to enable an infant seated on the walker to turn freely is disclosed in U.S. patent application Ser. No. 09/583,995 entitled “Baby Walker” wherein an annular flange is provided on tray with a rotatable disk member mounted thereon. The rotatable disk member comprises an outer wall, a top surface, and an inner wall. An annular groove is formed on the rotatable disk member. The bottom of outer wall is in contact with the top of the tray. A plurality of flexible tabs is provided on the bottom of the inner wall of the rotatable disk member for snapping into a plurality of corresponding slots on the inner wall of the tray and secured thereto. A plurality of holes are provided on the top surface of the rotatable disk member for receiving a plurality of corresponding pegs of seat. This forms a swivel seat. This can prevent an infant from feeling monotonous after several times of using the baby walker. However, infant may easily rotate the seat to turn its back on a parent of guardian who prepares to feed the infant. This really bothers the parent or guardian. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a mechanism for locking a swivel seat of baby walker in one of predetermined positions for facilitating the feeding by parent/guardian or the playing of infant. 
     The advantages of the present invention are realized by providing a baby walker comprising a stationary tray, a swivel mechanism, a seat, a circular base, a plurality of legs, a lock member, and a plurality of wheels rotatably mounted under the base. Tray is capable of supporting seat, seated infant, and the swivel mechanism. Legs are intercoupled the base and the tray for supporting the tray at a predetermined height above the ground. Swivel mechanism is rotatbly mounted on tray and comprises a plurality of dents wherein the lock member is capable of engaging with one of the dents for fastening the seat to the swivel mechanism. 
     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 first preferred embodiment of a baby walker incorporating a mechanism locking swivel seat according to the invention; 
     FIG. 2 is a perspective view of the FIG. 1 baby walker; 
     FIG. 3 is a side view schematically showing the seat, the lock member, and associated components shown in FIG. 1; 
     FIG. 4 is a view similar to FIG. 3 schematically showing the seat, the lock member, and associated components according to a second preferred embodiment of the invention; 
     FIGS. 5A,  5 B, and  5 C are schematic cross-sectional views illustrating the locking operation of seat according to the first preferred embodiment of the invention; 
     FIGS. 6A,  6 B, and  6 C views similar to FIGS. 5A,  5 B, and  5 C respectively for illustrating the locking operation of seat according to a first modification of the first preferred embodiment of the invention; 
     FIGS. 7A,  7 B, and  7 C are schematic cross-sectional views illustrating the locking operation of seat according to the second preferred embodiment of the invention; and 
     FIGS. 8A,  8 B, and  8 C views similar to FIGS. 7A,  7 B, and  7 C respectively for illustrating the locking operation of seat according to a first modification of the second preferred embodiment of the invention. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring to FIGS. 1 to  3 , there is shown a baby walker constructed in accordance with the invention comprising a stationary tray  10 , a swivel mechanism  20 , a seat  30 , a circular base  40 , a plurality of legs  51 ,  52 , and  53 , and a lock member  60 . Each of above components will now be described below. Tray  10  is capable of supporting seat  30  and comprises a central circular opening  101 , an annular groove  102  around opening  101  with a plurality of steel balls  70  slidingly and rotatably disposed therein, a plurality of recesses  105 ,  106 , and  107  on the underside of tray  10 , a toy area  103 , and a flat area  104  for retaining food, a beveage, or the like. Swivel mechanism  20  is a ring like member and consists of an upper member  21  and a lower member  22 . Upper member  21  is sized to conform to circular opening  101 . An annular ridge (not shown) is provided on upper member  21  inserted into annular groove  102  of tray  10  such that upper member  21  may turn freely about balls  70  on tray  10 . A plurality of slots  211  are provided on the inner periphery of upper member  21 . A plurality of threaded holes  212  are provided on the top surface of upper member  21 . A plurality of dents  213  are provided on the outer surface of upper member  21  (FIG.  3 ). As such, lock member  60  on tray  10  may be engaged with one of the dents  213  so as to secure seat  30  to tray  10 . Lower member  22  is also shaped to conform to circular opening  101  and comprises an annular flange  221  having an outer diameter slightly smaller than the diameter of the circular opening  101 . A plurality of tabs  222  are provided around the top surface of flange  221  of lower member  221 . Lower member  22  is inserted from below and into the circular opening  101  with tabs  222  snapped into slots  211  for securing lower member  22  and upper member  21  together. As a result, swivel mechanism  20  may turn freely about the circular opening  101  of tray  10 . 
     Seat  30  is adapted to receive an infant and comprises an annular frame  301  and a fabric portion  302 . A plurality of holes  3011  are provided around the top surface of frame  301  such that a plurality of screws  90  may drive through holes  3011  and threaded holes  212  to secure seat  30  to upper member  21 . Hence, frame  301  together with swivel mechanism  20  may freely turn. An infant may sit on the fabric portion  302  on the bottom of seat  30 . Fabric portion  302  is stitched to the periphery of frame  301 . Two leg openings  3021  are formed on the fabric portion  302  of seat  30  such that infant may extend its legs therethrough. Base  40  comprises a plurality of upward sockets  41 ,  42 , and  43 . Further, legs  51 ,  52 , and  53  are intercoupled the sockets  41 ,  42 , and  43  and the recesses  105 ,  106 , and  107  respectively. As such, tray  10  is supported at a predetermined height above the base  40  (or the ground). Referring to FIGS. 5A to  5 C, the mechanism for fastening swivel mechanism  20  to swivel seat  30  by means of lock member  60  is detailed below. Lock member  60  is provided on the top surface of tray  10 . Lock member  60  is substantially an elongate bar and comprises two opposite indentation  61  on the shank and an elastic member  80 ′ anchored on a portion of the recessed part on the shank. Two opposite holes  108  are provided in tray  10  each for receiving an elastic member  80  and a steel ball  70 ′ (i.e., depressible spring detent). With this, lock member  60  may be configured in a retained, free, or locked state. When lock member  60  is pulled to cause balls  70  to move into indentations  61  by the expansion of elastic members  80 , elastic member  80 ′ is compressed in the recessed part of lock member  60  within tray  10  (FIG.  5 A). At this position, lock member  60  is in the retained state. Further, when lock member  60  is pushed to engage with upper member  21  for causing indentations  61  to disengage from balls  70 , elastic members  80  are compressed and elastic member  80 ′ is expanded (FIG.  5 B). At this position, lock member  60  is in the free state. Furthermore, when swivel mechanism  20  is rotated until one of dents  213  is aligned with the inner end of lock member  60 , elastic member  80 ′ is further expanded to bias the inner end of lock member  60  to move into engagement with the dent  213  (FIG.  5 C). At this position, lock member  60  is in the locked state. 
     Referring to FIGS. 6A to  6 C, the configuration and the locking operation of seat according to a first modification of the first preferred embodiment of the invention are illustrated. The first modification of the first preferred embodiment is configured substantially the same as that of the first preferred embodiment except that the location of elastic member  80 ′ is inverse to that shown in FIGS. 5A to  5 C. 
     Referring to FIGS. 4,  7 A,  7 B, and  7 C, the configuration and the locking operation of seat according to a second preferred embodiment of the invention are detailed below. Lock member  60  is provided on the top surface of upper member  21  while dents  213  are provided in tray  10 . Lock member  60  is substantially a T-shaped member and comprises two opposite indentations  61  on the shank and an elastic member  80 ′ anchored on a portion of the recessed part on the shank. Two opposite holes  108  are provided in tray  10  each for receiving an elastic member  80  and a steel ball  70 ′ (i.e., depressible spring detent). With this, lock member  60  may be configured in a retained, free, or locked state. When lock member  60  is pulled to cause balls  70  to move into indentations  61  by the expansion of elastic members  80 , elastic member  80 ′ is compressed in the recessed part of lock member  60  within tray  10  (FIG.  7 A). At this position, lock member  60  is in the retained state. Further, when lock member  60  is pushed to engage with upper member  21  for causing indentations  61  to disengage from balls  70 , elastic members  80  are compressed and elastic member  80 ′ is expanded (FIG.  7 B). At this position, lock member  60  is in the free state. Furthermore, when swivel mechanism  20  is rotated until one of dents  213  is aligned with the inner end of lock member  60 , elastic member  80 ′ is further expanded to bias the inner end of lock member  60  to move into engagement with the dent  213  (FIG.  7 C). At this position, lock member  60  is in the locked state. 
     Referring to FIGS. 8A to  8 C, the configuration and the locking operation of seat according to a first modification of the second preferred embodiment of the invention are illustrated. The first modification of the second preferred embodiment is configured substantially the same as that of the second preferred embodiment except that the location of elastic member  80 ′ is inverse to that shown in FIGS. 7A to  7 C. 
     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.