GB2474422A

GB2474422A - Foldable high chair

Info

Publication number: GB2474422A
Application number: GB0917502A
Authority: GB
Inventors: Chuan-Kai Hsu
Original assignee: WEI GUAN HARWAEW
Current assignee: WEI GUAN HARWAEW
Priority date: 2009-10-07
Filing date: 2009-10-07
Publication date: 2011-04-20
Anticipated expiration: 2029-10-07
Also published as: FR2951921B3; GB0917502D0; GB2474422B; FR2951921A3

Abstract

A foldable high chair includes a support unit 6, a backrest unit 2 pivotally mounted on the support unit 6, a seat unit 4 pivotally mounted on the backrest unit 2, an armrest and table assembly 1 mounted on the backrest unit 2, two folding devices 5 mounted on the support unit 6, and a control device 3 mounted on the backrest unit 2 to control operation of the backrest unit 2 so as to releasably lock the seat unit 4 and the two folding devices 5. The high chair may be folded when not in use to allow for ease of storage and transportation. The table may be pivoted and moved outward so that the child can be placed on the seat unit.

Description

FOLDABLE HIGH CHAIR

The present invention relates to a high chair and, more particularly, to a foldable high chair for children or babies.

A conventional high chair for children comprises a stand, a seat secured on the stand, a backrest secured on the seat, two armrests secured on the backrest and located above the seat, and a table pivotally mounted on the backrest and abutting the armrests. However, the high chair cannot be folded when not in use, thereby causing inconvenience in storage and transportation of the high chair. In addition, the table is fixed on and cannot be removed from the backrest, so that the child cannot be placed onto the seat easily and quickly.

In accordance with the present invention, there is provided a foldable high chair, comprising a support unit, a backrest unit pivotally mounted on the support unit, a seat unit pivotally mounted on and releasably locked by the backrest unit, an armrest and table assembly mounted on the backrest unit and the support unit and located above the seat unit, two folding devices mounted on the support unit and releasably locked by the backrest unit, and a control device mounted on the backrest unit to control operation of the backrest unit so as to releasably lock the seat unit and to releasably lock the two folding devices respectively.

According to the primary objective of the present invention, the table can be pivoted about the rotation member to move outward so that the child can be placed on the seat unit easily and quickly.

According to another objective of the present invention, the rotation member is removed from the receiving hole of the right support base so that the table is removed from the right support base easily and quickly.

According to a further objective of the present invention, the front gear and the rear gear of each of the two folding devices mesh with each other so that the front frame and the rear frame of the support unit are moved and folded simultaneously and will not clamp or hurt the user due to a rapid folding action.

Further benefits and advantages of the present invention will become apparent after a careful reading of the detailed description with appropriate reference to the accompanying drawings.

In the drawings: Fig. 1 is a perspective view of a foldable high chair in accordance with the preferred embodiment of the present invention.

Fig. 2 is a partially exploded perspective view of the foldable high chair as shown in Fig. 1.

Fig. 3 is an exploded perspective view of an armrest and table assembly of the foldable high chair as shown in Fig. 1.

Fig. 4 is an exploded perspective view of a backrest unit and a control device of the foldable high chair as shown in Fig. 1.

Fig. 5 is an exploded perspective view of a folding device of the foldable high chair as shown in Fig. 1.

Fig. 6 is a side view of the foldable high chair as shown in Fig. 1.

Fig. 7 is a locally enlarged cross-sectional view of the foldable high chair as shown in Fig. 6.

Fig. 8 is a cross-sectional view of the foldable high chair as shown in Fig. 6.

Fig. 9 is a rear view of the foldable high chair as shown in Fig. 1.

Fig. 10 is a locally enlarged cross-sectional view of the foldable high chair as shown in Fig. 9.

Fig. 11 is a schematic operational view of the foldable high chair as shown in Fig. 1.

Fig. 12 is a schematic operational view of the foldable high chair as shown in Fig. 1.

Fig. 13 is a schematic operational view of the foldable high chair as shown in Fig. 7.

Fig. 14 is a schematic operational view of the foldable high chair as shown in Fig. 6.

Fig. 15 is a schematic operational view of the foldable high chair as shown in Fig. 14.

Referring to the drawings and initially to Figs. 1-10, a foldable high chair for children in accordance with the preferred embodiment of the present invention comprises a support unit 6, a backrest unit 2 pivotally mounted on the support unit 6, a seat unit 4 pivotally mounted on and releasably locked by the backrest unit 2, an armrest and table assembly 1 mounted on the backrest unit 2 and the support unit 6 and located above the seat unit 4, two folding devices 5 mounted on the support unit 6 and releasably locked by the backrest unit 2, and a control device 3 mounted on the backrest unit 2 to control operation of the backrest unit 2 so as to releasably lock the seat unit 4 and to releasably lock the two folding devices 5 respectively.

The armrest and table assembly I includes two armrests 14 each pivotally mounted on the backrest unit 2, a right support base 13 mounted on one of the two armrests 14 and supported by the support unit 6, a left support base 15 mounted on the other one of the two armrests 14 and supported by the support unit 6, a table 11 swivelably mounted on the right support base 13 and detachably locked onto the left support base 15, a mounting base 113 mounted on a bottom of the table 11, an upright stop rod 114 mounted on a bottom of the mounting base 113 and disposed between the right support base 13 and the left support base 15 to prevent a baby or child from slipping outward from the seat unit 4, a rotation member 12 mounted on the table 11 and rotatably mounted on the right support base 13, a locking plug 112 mounted on the table 11 and detachably locked onto the left support base 15 to releasably lock the table 11 onto the left support base 15, and a substantially U-shaped support tube 111 mounted on the bottom of the table 11 to support the locking plug 112.

The right support base 13 of the armrest and table assembly 1 has a top provided with a receiving hole 131 to receive and allow rotation of the rotation member 12. The left support base 15 of the armrest and table assembly 1 has an end provided with a locking hole 152 to releasably lock the locking plug 112.

The support unit 6 includes a front frame 62, a rear frame 61 pivotally connected with the front frame 62 and an upper frame 63 pivotally connected with the front frame 62 to support the right support base 13 and the left support base 15 of the armrest and table assembly 1. The front frame 62 of the support unit 6 is substantially U-shaped, and the rear frame 61 of the support unit 6 is substantially U-shaped.

The two folding devices 5 are mounted on two opposite sides of the front frame 62 and two opposite sides of the rear frame 61 to fold and expand the front frame 62 and the rear frame 61 of the support unit 6. Each of the two folding devices 5 includes a rear gear 52 secured on the rear frame 61 of the support unit 6 to move in concert with the rear frame 61 of the support unit 6, a front gear 54 secured on the front frame 62 of the support unit 6 to move in concert with the front frame 62 of the support unit 6 and meshing with the rear gear 52 so that the front frame 62 and the rear frame 61 of the support unit 6 are movable relative to each other simultaneously, a rear fixing block 53 secured on the rear gear 52 and releasably locked by operation of the control device 3 to releasably lock the rear gear 52, a front fixing block 55 secured on the front gear 54 and releasably locked by operation of the control device 3 to releasably lock the front gear 54, and a housing 51 mounted between the front frame 62 and the rear frame 61 of the support unit 6 to receive the front gear 54, the rear gear 52, the front fixing block 55 and the rear fixing block 53.

The rear gear 52 of each, of the two folding devices 5 has a side provided with a fixing recess 521 to fix the rear fixing block 53. The rear fixing block 53 of each of the two folding devices 5 has a side provided with a rear locking groove 531. The front fixing block 55 of each of the two folding devices 5 has a side provided with a front locking groove 551.

The seat unit 4 includes a seat 41 pivotally mounted on the backrest unit 2, a pedal rack 42 pivotally mounted on the backrest unit 2 and located under the seat 41, two connecting rods 43 each mounted between the seat 41 and the pedal rack 42 to connect and move the seat 41 and the pedal rack 42 simultaneously, and two mounting blocks 421 mounted on the pedal rack 42 and releasably locked by operation of the control device 3 to releasably lock the pedal rack 42.

The seat 41 of the seat unit 4 has a side provided with a penetrated handgrip 411. The pedal rack 42 of the seat unit 4 is substantially U-shaped.

Each of the mounting blocks 421 of the seat unit 4 is pivotally mounted on the backrest unit 2 and has a side provided with a locking recess 422.

The backrest unit 2 includes a backrest bracket 21 pivotally mounted on the support unit 6 and located between the pedal rack 42 of the seat unit 4 and the two folding devices 5, two fixed sleeves 22 secured on the backrest bracket 21, two movable sleeves 23 movably mounted on the two fixed sleeves 22 respectively and each having a locking boss 231 that is movable to releasably lock the rear fixing block 53 of a respective folding device 5, a locking stub 233 that is movable to releasably lock the front fixing block 55 of the respective folding device 5 and a locking knob 235 that is movable to releasably lock a respective mounting block 421 of the seat unit 4, two elastic members 24 each biased between the backrest bracket 21 and a respective movable sleeve 23, and a soft cushion 211 mounted on an upper end of the backrest bracket 21 to provide a buffering effect.

Each of the two movable sleeves 23 of the backrest unit 2 is movably mounted on the respective fixed sleeve 22 by a guide pin 232. The guide pin 232 extends through each of the two movable sleeves 23, each of the two fixed sleeves 22 and the backrest bracket 21. The locking boss 231 of each of the two movable sleeves 23 is inserted into and releasably locked in the rear locking groove 531 of the rear fixing block 53 to lock the rear gear 52, the locking stub 233 of each of the two movable sleeves 23 is inserted into and releasably locked in the front locking groove 551 of the front fixing block 55 to lock the front gear 54, and the locking knob 235 of each of the two movable sleeves 23 is inserted into and releasably locked in the locking recess 422 of each of the mounting blocks 421 to lock the pedal rack 42.

The backrest bracket 21 of the backrest unit 2 is substantially inverted U-shaped and has two opposite sides each provided with an elongate guide groove 215 to allow passage and movement of the guide pin 232 and a stop pin 213 to stop a respective elastic member 24. The two fixed sleeves 22 of the backrest unit 2 are secured on lower ends of the two opposite sides of the backrest bracket 21. Each of the two fixed sleeves 22 of the backrest unit 2 has an elongate guide slot 221 to allow passage and movement of the guide pin 232.

Each of the two elastic members 24 of the backrest unit 2 is biased between the respective stop pin 213 of the backrest bracket 21 and the guide pin 232 of the respective movable sleeve 23. Each of the two elastic members 24 of the backrest unit 2 is compressed when the respective movable sleeve 23 is moved upward relative to the respective fixed sleeve 22 and the backrest bracket 21.

The control device 3 includes a casing 31 mounted on the backrest bracket 21 of the backrest unit 2, a pull bar 32 pivotally mounted on the casing 31, two drive cords 34 each having a lower end secured to a respective movable sleeve 23 of the backrest unit 2 to move the respective movable sleeve 23 of the backrest unit 2 and an upper end secured to and driven by the pull bar 32, a fastening knob 33 movably mounted on the casing 31 and movable to abut the pull bar 32 so as to releasably lock the pull bar 32 onto the casing 31, and a push spring 331 biased between the casing 31 and the fastening knob 33 to push the fastening knob 33 toward the pull bar 32.

The pull bar 32 of the control device 3 has a side provided with a locking channel 321 to releasably lock the fastening knob 33. The pull bar 32 of the control device 3 has a first end pivotally mounted on the casing 31 and a second end connected with the upper end of each of the two drive cords 34.

Each of the two drive cords 34 of the control device 3 is received in the backrest bracket 21 of the backrest unit 2. The casing 31 of the control device 3 has an inside provided with a receiving chamber 311 to receive the fastening knob 33 and the push spring 331.

In operation, referring to Figs. 11-15 with reference to Figs. 1-10, the rotation member 12 is rotatable on the right support base 13, so that the table 11 can be pivoted about the rotation member 12 to move outward as shown in Fig. 11 so as to open the seat unit 4. Thus, the child can be placed on the seat unit 4 easily and quickly. After the child is placed on the seat unit 4, the table 11 can be pivoted about the rotation member 12 to move inward so as to close the seat unit 4. At this time, the locking plug 112 is inserted into and locked in the locking hole 152 of the left support base 15 to lock the table 11 onto the left support base 15.

As shown in Fig. 12, the rotation member 12 is removed from the receiving hole 131 of the right support base 13 so that the table 11 is removed from the right support base 13 easily and quickly.

As shown in Figs. 4, 5 and 9, each of the two movable sleeves 23 is pushed by the respective elastic member 24 to move downward relative to the respective fixed sleeve 22 so that the locking boss 231 of each of the two movable sleeves 23 is inserted into and releasably locked in the rear locking groove 531 of the rear fixing block 53 to lock the rear gear 52, the locking stub 233 of each of the two movable sleeves 23 is inserted into and releasably locked in the front locking groove 551 of the front fixing block 55 to lock the front gear 54, and the locking knob 235 of each of the two movable sleeves 23 is inserted into and releasably locked in the locking recess 422 of each of the mounting blocks 421 to lock the pedal rack 42. Thus, the seat unit 4 and the support unit 6 are locked by the movable sleeves 23 of the backrest unit 2 at a normal state. At this time, the fastening knob 33 is pushed by the push spring 331 and is inserted into and releasably locked in the locking channel 321 of the pull bar 32 to stop movement of the pull bar 32.

When a user wishes to fold the high chair, the fastening knob 33 is pulled to detach from the locking channel 321 of the pull bar 32 and to unlock the pull bar 32 as shown in Fig. 10. Thus, the pull bar 32 can be pulled outward to pull the two drive cords 34 which drive the movable sleeves 23 to move upward relative to the fixed sleeves 22 as shown in Fig. 8 so that the locking boss 231 of each of the two movable sleeves 23 is detached from the rear locking groove 531 of the rear fixing block 53 to unlock the rear gear 52, the locking stub 233 of each of the two movable sleeves 23 is detached from the front locking groove 551 of the front fixing block 55 to unlock the front gear 54, and the locking knob 235 of each of the two movable sleeves 23 is detached from the locking recess 422 of each of the mounting blocks 421 to unlock the pedal rack 42. In such a manner, the front gear 54 and the rear gear 52 of each of the two folding devices 5 are unlocked and can be rotated freely, so that the front frame 62 and the rear frame 61 of the support unit 6 can be moved freely I0 as shown in Fig. 13. At the same time, each of the mounting blocks 421 of the seat unit 4 is unlocked and can be pivoted freely so that the pedal rack 42 of the seat unit 4 ôan be pivoted freely.

When the front frame 62 and the rear frame 61 of the support unit 6 are moved toward each other, the armrest and table assembly 1 is pulled downward by the upper frame 63 of the support unit 6 to pull and pivot the backrest unit 2 downward which pulls the seat unit 4 downward. Thus, when the front frame 62 and the rear frame 61 of the support unit 6 are moved from the position as shown in Figs. 6 and 7 to the position as shown in Figs. 13 and 14, the armrest and table assembly 1, the backrest unit 2 and the seat unit 4 are moved downward so that when the support unit 6 is folded, the armrest and table assembly 1, the backrest unit 2 and the seat unit 4 are also folded simultaneously. At this time, the handgrip 411 of the seat 41 facilitates the user holding and folding the high chair.

As shown in Fig. 15, the armrest and table assembly 1, the backrest unit 2 and the seat unit 4 are further moved downward and folded between the front frame 62 and the rear frame 61 of the support unit 6 so that the high chair is folded completely.

Accordingly, the table 11 can be pivoted about the rotation member 12 to move outward so that the child can be placed on the seat unit 4 easily and quickly. In addition, the rotation member 12 is removed from the receiving hole 131 of the right support base 13 so that the table 11 is removed from the right support base 13 easily and quickly. Further, the front gear 54 and the rear gear 52 of each of the two folding devices 5 mesh with each other so that the front frame 62 and the rear frame 61 of the support unit 6 are moved and folded simultaneously and will not clamp or hurt the user due to a rapid folding action.

Although the invention has been explained in relation to its preferred embodiment(s) as mentioned above, it is to be understood that many other possible modifications and variations can be made without departing from the scope of the present invention. It is, therefore, contemplated that the appended claim or claims will cover such modifications and variations that fall within the true scope of the invention.

Claims

CLAIMS1. A foldable high chair, comprising: a support unit (6); a backrest unit (2) pivotally mounted on the support unit; a seat unit (4) pivotally mounted on and releasably locked by the backrest unit; an armrest and table assembly (1) mounted on the backrest unit and the support unit and located above the seat unit; two folding devices (5) mounted on the support unit and releasably locked by the backrest unit; a control device (3) mounted on the backrest unit to control operation of the backrest unit so as to releasably lock the seat unit and to releasably lock the two folding devices respectively.
2. The foldable high chair of claim 1, wherein the armrest and table assembly includes: two armrests (14) each pivotally mounted on the backrest unit; a right support base (13) mounted on one of the two armrests and supported by the support unit; a left support base (15) mounted on the other one of the two armrests and supported by the support unit; a table (11) swivelably mounted on the right support base and detachably locked onto the left support base; a rotation member (12) mounted on the table and rotatably mounted on the right support base.
3. The foldable high chair of claim 1, wherein the support unit includes: a front frame (62); a rear frame (61) pivotally connected with the front frame; each of the two folding devices includes: a rear gear (52) secured on the rear frame of the support unit to move in concert with the rear frame of the support unit; a front gear (54) secured on the front frame of the support unit to move in concert with the front frame of the support unit and meshing with the rear gear so that the front frame and the rear frame of the support unit are movable relative to each other simultaneously; a rear fixing block (53) secured on the rear gear and releasably locked by operation of the control device to releasably lock the rear gear; a front fixing block (55) secured on the front gear and releasably locked by operation of the control device to releasably lock the front gear.
4. The foldable high chair of claim 3, wherein the seat unit includes: a seat (41) pivotally mounted on the backrest unit; a pedal rack (42) pivotally mounted on the backrest unit and located under the seat; two connecting rods (43) each mounted between the seat and the pedal rack to connect and move the seat and the pedal rack simultaneously; two mounting blocks (421) mounted on the pedal rack and releasably locked by operation of the control device to releasably lock the pedal rack.
5. The foldable high chair of claim 4, wherein the seat of the seat unit has a side provided with a penetrated handgrip (411).
6. The foldable high chair of claim 4, wherein the backrest unit includes: a backrest bracket (21) pivotally mounted on the support unit and located between the pedal rack of the seat unit and the two folding devices; two fixed sleeves (22) secured on the backrest bracket; two movable sleeves (23) movably mounted on the two fixed sleeves respectively and each having a locking boss (231) that is movable to releasably lock the rear fixing block of a respective folding device, a locking stub (233) that is movable to releasably lock the front fixing block of the respective folding device and a locking knob (235) that is movable to releasably lock a respective mounting block of the seat unit; two elastic members (24) each biased between the backrest bracket and a respective movable sleeve.
7. The foldable high chair of claim 6, wherein the control device includes: a casing (31) mounted on the backrest bracket of the backrest unit; a pull bar (32) pivotally mounted on the casing; two drive cords (34) each having a lower end secured to a respective movable sleeve of the backrest unit to move the respective movable sleeve of the backrest unit and an upper end secured to and driven by the pull bar; a fastening knob (33) movably mounted on the casing and movable to abut the pull bar so as to releasably lock the pull bar onto the casing; a push spring (331) biased between the casing and the fastening knob to push the fastening knob toward the pull bar.
8. The foldable high chair of claim 2, wherein the armrest and table assembly further includes: a mounting base (113) mounted on a bottom of the table; an upright stop rod (114) mounted on a bottom of the mounting base and disposed between the right support base and the left support base; a locking plug (112) mounted on the table and detachably locked onto the left support base to releasably lock the table onto the left support base.
9. The foldable high chair of claim 8, wherein the right support base of the armrest and table assembly has a top provided with a receiving hole (131) to receive and allow rotation of the rotation member; the left support base of the armrest and table assembly has an end provided with a locking hole (152) to releasably lock the locking plug.
10. The foldable high chair of claim 6, wherein the two folding devices are mounted on two opposite sides of the front frame and two opposite sides of the rear frame to fold and expand the front frame and the rear frame of the support unit; the rear gear of each of the two folding devices has a side provided with a fixing recess (521) to fix the rear fixing block; the rear fixing block of each of the two folding devices has a side provided with a rear locking groove (531); the front fixing block of each of the two folding devices has a side provided with a front locking groove (551); each of the mounting blocks of the seat unit is pivotally mounted on the backrest unit and has a side provided with a locking recess (422); the locking boss of each of the two movable sleeves is inserted into and releasably locked in the rear locking groove of the rear fixing block to lock the rear gear; the locking stub of each of the two movable sleeves is inserted into and releasably locked in the front locking groove of the front fixing block to lock the front gear; the locking knob of each of the two movable sleeves is inserted into and releasably locked in the locking recess of each of the mounting blocks to lock the pedal rack.
11. The foldable high chair of claim 3, wherein each of the two folding devices further includes: a housing (51) mounted between the front frame and the rear frame of the support unit to receive the front gear, the rear gear, the front fixing block and the rear fixing block.
12. The foldable high chair of claim 6, wherein the backrest unit further includes: a soft cushion (211) mounted on an upper end of the backrest bracket to provide a buffering effect.
13. The foldable high chair of claim 7, wherein the pull bar of the control device has a side provided with a locking channel (321) to releasably lock the fastening knob; the casing of the control device has an inside provided with a receiving chamber (311) to receive the fastening knob and the push spring.
14. The foldable high chair of claim 2, wherein the armrest and table assembly further includes: a substantially U-shaped support tube (111) mounted on the bottom of the table to support the locking plug.
15. The foldable high chair of claim 6, wherein each of the two movable sleeves of the backrest unit is movably mounted on the respective fixed sleeve by a guide pin (232); the guide pin extends through each of the two movable sleeves, each of the two fixed sleeves and the backrest bracket; the backrest bracket of the backrest unit is substantially inverted U-shaped and has two opposite sides each provided with an elongate guide groove (215) to allow passage and movement of the guide pin and a stop pin (213) to stop a respective elastic member; each of the two elastic members of the backrest unit is biased between the respective stop pin of the backrest bracket and the guide pin of the respective movable sleeve; the two fixed sleeves of the backrest unit are secured on lower ends of the two opposite sides of the backrest bracket; each of the two fixed sleeves of the backrest unit has an elongate guide slot to allow passage and movement of the guide pin.
16. The foldable high chair of claim 7, wherein the pull bar of the control device has a first end pivotally mounted on the casing and a second end connected with the upper end of each of the two drive cords; each of the two drive cords of the control device is received in the backrest bracket of the backrest unit.
17. The foldable high chair of claim 4, wherein the pedal rack of the seat unit is substantially U-shaped.
18. The foldable high chair of claim 6, wherein each of the two elastic members of the backrest unit is compressed when the respective movable sleeve is moved upward relative to the respective fixed sleeve and the backrest bracket.
19. The foldable high chair of claim 3, wherein the front frame of the support unit is substantially U-shaped; the rear frame of the support unit is substantially U-shaped.
20. The foldable high chair of claim 3, wherein the support unit further includes: an upper frame (63) pivotally connected with the front frame to support the right support base and the left support base of the armrest and table assembly.
21. A foldable high chair substantially as hereinbefore described with reference to and as shown in the accompanying drawings.AMENDMENTS TO THE CLAIMS HAVE BEEN FILED AS FOLLOWSCLAIMS1. A foldable high chair, comprising: a support unit (6); a backrest unit (2) pivotally mounted on the support unit; a seat unit (4) pivotally mounted on the backrest unit; two folding devices (5) mounted on the support unit; an armrest and table assembly (1) mounted on the backrest unit and the two folding devices and located above the seat unit; a control device (3) mounted on the backrest unit and operable so as to releasably lock the seat unit and to releasably lock the two folding devices respectively, the control device including a casing (31) mounted on the backrest unit, a pull bar (32) pivotally mounted on the casing, a fastening knob (33) movably mounted on the casing and movable to abut the pull bar so as to releasably lock the pull bar onto the casing, and a push spring (331) acting * . 15 between the casing and the fastening knob to push the fastening knob towards *..* the pull bar.2. The foldable high chair of claim 1, wherein the armrest and table *..assembly includes: * I* :::; two armrests (14) each pivotally mounted on the backrest unit; a right support base (13) mounted on one of the two armrests and supported by the support unit; a left support base (15) mounted on the other one of the two armrests and supported by the support unit; a table (11) swivelably mounted on the right support base and detachably locked onto the left support base; a rotation member (12) mounted on the table and rotatably mounted on the right support base.3. The foldable high chair of claim 1, wherein the support unit includes: a front frame (62); a rear frame (61) pivotally cormected with the front frame; each of the two folding devices includes: a rear gear (52) secured on the rear frame of the support unit to move in concert with the rear frame of the support unit; a front gear (54) secured on the front frame of the support unit to move in concert with the front frame of the support unit and meshing with the .e * rear gear so that the front frame and the rear frame of the support unit are I...movable relative to each other simultaneously;S S..* . a rear fixing block (53) secured on the rear gear and releasably locked by operation of the control device to releasably lock the rear gear; a front fixing block (55) secured on the front gear and releasably locked by operation of the control device to releasably lock the front gear.4. The foldable high chair of claim 3, wherein the seat unit includes: a seat (41) pivotally mounted on the backrest unit; a pedal rack (42) pivotally mounted on the backrest unit and located under the seat; two connecting rods (43) each mounted between the seat and the pedal rack to connect and move the seat and the pedal rack simultaneously; two mounting blocks (421) mounted on the pedal rack and releasably locked by operation of the control device to releasably lock the pedal rack.5. The foldable high chair of claim 4, wherein the seat of the seat unit has a side provided with a penetrated handgrip (411).6. The foldable high chair of claim 4, wherein the backrest unit includes: a backrest bracket (21) pivotally mounted on the support unit and located between the pedal rack of the seat unit and the two folding devices; two fixed sleeves (22) secured on the backrest bracket; two movable sleeves (23) movably mounted on the two fixed sleeves respectively and each having a locking boss (231) that is movable to releasably S... * S *..*.: lock the rear fixing block of a respective folding device, a locking stub (233) that is movable to releasably lock the front fixing block of the respective *..* folding device and a locking knob (235) that is movable to releasably lock a * S. respective mounting block of the seat unit; two elastic members (24) each biased between the backrest bracket and a respective movable sleeve.7. The foldable high chair of claim 6, wherein the casing of the control device is mounted on the backrest bracket of the backrest unit; and in which the control device includes two drive cords (34) each having a lower end secured to a respective movable sleeve of the backrest unit to move the respective movable sleeve of the backrest unit and an upper end secured to and driven by the pull bar.8. The foldable high chair of claim 2, wherein the armrest and table assembly further includes: a mounting base (113) mounted on a bottom of the table; an upright stop rod (114) mounted on a bottom of the mounting base and disposed between the right support base and the left support base; a locking plug (112) mounted on the table and detachably locked onto the left support base to releasably lock the table onto the left support base.9. The foldable high chair of claim 8, wherein the right support base of the armrest and table assembly has a top provided with a receiving hole (131) to receive and allow rotation of the * * S...rotation member; the left support base of the armrest and table assembly has an end *..provided with a locking hole (152) to releasably lock the locking plug.10. The foldable high chair of claim 6, wherein the two folding devices are mounted on two opposite sides of the front frame and two opposite sides of the rear frame to fold and expand the front frame and the rear frame of the support unit; the rear gear of each of the two folding devices has a side provided with a fixing recess (521) to fix the rear fixing block; the rear fixing block of each of the two folding devices has a side provided with a rear locking groove (531); the front fixing block of each of the two folding devices has a side provided with a front locking groove (551); each of the mounting blocks of the seat unit is pivotally mounted on the backrest unit and has a side provided with a locking recess (422); the locking boss of each of the two movable sleeves is inserted into and releasably locked in the rear locking groove of the rear fixing block to lock the rear gear; the locking stub of each of the two movable sleeves is inserted into and releasably locked in the front locking groove of the front fixing block to * * **S.lock the front gear; the locking knob of each of the two movable sleeves is inserted into and releasably locked in the locking recess of each of the mounting blocks to *20 lock the pedal rack.11. The foldable high chair of claim 3, wherein each of the two folding devices further includes: a housing (51) mounted between the front frame and the rear frame of the support unit to receive the front gear, the rear gear, the front fixing block and the rear fixing block.12. The foldable high chair of claim 6, wherein the backrest unit further includes: a soft cushion (211) mounted on an upper end of the backrest bracket to provide a buffering effect.13. The foldable high chair of claim 7, wherein the pull bar of the control device has a side provided with a locking channel (321) to releasably lock the fastening knob; the casing of the control device has an inside provided with a receiving chamber (311) to receive the fastening knob and the push spring.14. The foldable high chair of claim 2, wherein the armrest and table assembly further includes: a substantially U-shaped support tube (111) mounted on the bottom of the table to support the locking plug. *SSS * *15. The foldable high chair of claim 6, wherein * : each of the two movable sleeves of the backrest unit is movably * S.. . . mounted on the respective fixed sleeve by a guide pin (232); the guide pin extends through each of the two movable sleeves, each of the two fixed sleeves and the backrest bracket; the backrest bracket of the backrest unit is substantially inverted U-shaped and has two opposite sides each provided with an elongate guide groove (215) to allow passage and movement of the guide pin and a stop pin (213) to stop a respective elastic member; each of the two elastic members of the backrest unit is biased between the respective stop pin of the backrest bracket and the guide pin of the respective movable sleeve; the two fixed sleeves of the backrest unit are secured on lower ends of the two opposite sides of the backrest bracket; each of the two fixed sleeves of the backrest unit has an elongate guide slot to allow passage and movement of the guide pin.16. The foldable high chair of claim 7, wherein the pull bar of the control device has a first end pivotally mounted on the casing and a second end connected with the upper end of each of the two drive cords; each of the two drive cords of the control device is received in the *..S * * **** backrest bracket of the backrest unit.17. The foldable high chair of claim 4, wherein the pedal rack of the 0**S seat unit is substantially U-shaped.18. The foldable high chair of claim 6, wherein each of the two elastic members of the backrest unit is compressed when the respective movable sleeve is moved upward relative to the respective fixed sleeve and the backrest bracket.19. The foldable high chair of claim 3, wherein the front frame of the support unit is substantially U-shaped; the rear frame of the support unit is substantially U-shaped.20. The foldable high chair of claim 3, wherein the support unit further includes: an upper frame (63) pivotally connected with the front frame to support the right support base and the left support base of the armrest and table assembly.21. A foldable high chair substantially as hereinbefore described with reference to and as shown in the accompanying drawings. *S.. * **..... * * *s.*S S... S.. * *. * S *SS S * S *.