JP3194398U - Chair bottom plate structure - Google Patents

Abstract

A bottom plate structure of a chair having a plurality of adjusting functions is provided. A bottom plate structure of a chair includes a bottom plate, a rear rack, and a seat frame. The bottom plate 1 has a resilient support device 10, a tilt device 20 and an adjustment device 30. The resilient support device 10 has at least one elastic sheet mounted in the bottom plate 1, an adjustment component mounted in the bottom plate 1, and a support base coupled to the adjustment component. The tilting device 20 has a pivoting component coupled to the rear rack 2, a transmission pedestal mounted in the bottom plate 1, and two fastening members coupled to the bottom plate 1. The transmission pedestal has a tensile component coupled to the transmission pedestal. The adjustment device 30 is mounted between the bottom plate 1 and the seat frame 3 and has a rear pivot component 40 and a front adjustment component 50 mounted on the seat frame 3 and the bottom plate 1. [Selection] Figure 1

Description

  The present invention relates to a bottom plate of a chair, and more particularly to a bottom plate structure having a plurality of adjustment functions.

  A conventional chair includes a bottom plate, a rear rack, and a seat frame. The rear rack is always pivotably and elastically coupled to the bottom plate and rotates relative to the bottom plate. Thus, the user can stretch his or her body for relaxation.

  In order to achieve a relaxing effect, resilient components are used to join the bottom plate and the rear rack. As the user leans against the back of the rear rack, the resilient components can be stretched and the user's back can be stretched. When the user no longer rests on the back of the back rack, the back rack is repositioned to its original position by the resilient components.

  However, while conventional resilient components are stretched by the rear rack, the elasticity of the resilient components is fixed and non-adjustable. As the user sits for a long time and leans against the rear rack, the resilient components are fatigued by the user's leaning force, which affects the sitting comfort provided by the chair. Furthermore, different users have different demands on elasticity, and the user may wish that the elasticity of a resilient component can be adjusted to meet different conditions, whereas traditional resilient components are Does not have elasticity adjustment function.

  In addition, the user needs to adjust the rear rack rear tilt angle for different usage conditions. When the user sits in a chair, the rear rack is adjusted to a specific rear tilt angle so that the user's back can be stretched for relaxation. If the user is immersed in some work by sitting in a chair in a straight position, the rear rack is adjusted to a vertical angle to support the user.

  However, the rear rack of a conventional chair does not have multiple back tilt angles, but provides only two adjustment positions for the user, one of the adjustment positions being vertical and the other of the adjustment positions being Due to the specific rear tilt angle, the conventional chair rear rack adjustment function is inappropriate for the user.

  In addition, a cushion is mounted on a conventional chair seat frame. Usually, the seat frame is securely mounted on the bottom plate at a certain forward tilt angle to improve the comfort of the chair. Therefore, the front inclination angle of the seat frame cannot be adjusted. However, when a user sits on a conventional chair, users with different heights may prefer different forward tilt angles. The traditional chair clearly cannot meet the usage requirements.

  In order to overcome these drawbacks, the present invention provides a chair bottom plate structure to reduce or obviate the above problems.

  The main object of the present invention is to provide a bottom plate structure for a chair having a plurality of adjustment functions, including adjustment of a resilient support device, a tilt device, and an adjustment device. Thus, the present invention can satisfy different usage requirements of the user by adjusting the resilient support device, tilt device and adjustment device.

  The bottom plate structure of the chair includes a bottom plate, a rear rack that is pivotally coupled to the bottom plate, and a seat frame that is mounted on the bottom plate in front of the rear rack. The bottom plate has a resilient support device, tilt device, and adjustment device. The resilient support device includes at least an elastic sheet mounted in the bottom plate, an adjustment component, and a support base. The front end of the elastic sheet is firmly connected in the bottom plate, the rear end of the elastic sheet is connected to the rear rack in the bottom plate, the adjustment component is mounted in the bottom plate under the elastic sheet, and the support base is adjusted Moveably coupled to the component. The support base is positioned under the elastic sheet and contacts the elastic sheet.

  The tilting device includes a pivoting component coupled to the rear rack, a transmission pedestal mounted in the bottom plate, and two fastening members coupled to both sides in the bottom plate. The pivot component includes two pivot arms pivotally coupled to the bottom plate and securely attached to the rear rack, and a plurality of insertion slots formed oppositely on the two inner surfaces of the pivot arm. Have The insertion slots are arranged in a fan shape. The transmission pedestal comprises two cylinders positioned at the center of the bottom plate and extending from the two bottom surfaces of the transmission pedestal, a tension component coupled to the transmission pedestal, and two fastening members pivotally mounted within the bottom plate. Two fastening members each having two inclined holes attached so as to penetrate the cylinder of the transmission base, and two fastening sheets formed on the rear end of the fastening member and fastened in the insertion slot.

  The adjustment device is mounted between the bottom plate and the seat frame and has a rear pivot component and a front adjustment component. The rear pivoting component is mounted on the rear edge of the seat frame and the bottom plate. The front adjustment component is mounted on the front edge of the seat frame and the bottom plate. The front adjustment component is used to adjust the forward tilt angle of the seat frame relative to the bottom plate.

  Other objects, advantages and novel features of the present invention will become more apparent from the following detailed description when considered in conjunction with the accompanying drawings.

It is a perspective view of the baseplate structure of the chair which concerns on this invention. It is another perspective view of the baseplate structure in FIG. It is a fragmentary perspective view of the baseplate structure in FIG. It is another partial perspective view of the baseplate structure in FIG. It is a top view of the elastic support device of the baseplate structure in FIG. FIG. 6 is another top view of the resilient support device of the bottom plate structure in FIG. 1. It is an expansion perspective view of the support base of the baseplate structure in FIG. It is a top view which can operate | move the inclination device of the baseplate structure in FIG. It is another top view which can operate | move the tilting device of the baseplate structure in FIG. It is an expansion perspective view of the transmission base of the baseplate structure in FIG. FIG. 2 is an enlarged perspective view of a pivot arm having a bottom plate structure in FIG. 1. It is a perspective view which can operate | move the pivot arm and fastening member of the baseplate structure in FIG. It is an expansion perspective view of the fastening member of the baseplate structure in FIG. It is an exploded view of the seat frame and bottom plate of the baseplate structure in FIG. FIG. 2 is an enlarged perspective view of a front adjustment component of the bottom plate structure in FIG. 1. FIG. 16 is a front view of the front adjustment component of the bottom plate structure in FIG. 15. FIG. 2 is an enlarged exploded view of a front adjustment component of the bottom plate structure in FIG. 1. FIG. 4 is another enlarged exploded view of the front adjustment component of the bottom plate structure in FIG. 1. FIG. 5 is a cross-sectional side view of the front adjustment component of the bottom plate structure. FIG. 20 is an operable side view of the cushion structure adjustment module in FIG. 19.

  1 and 2, the bottom plate structure of a chair according to the present invention includes a bottom plate 1, a rear rack 2, and a seat frame 3.

  The bottom plate 1 has an upper surface, a front surface, a receiving groove 1A, a resilient support device 10, an inclination device 20, and an adjustment device 30. The housing groove 1 </ b> A is formed in the upper surface of the bottom plate 1 on the front surface of the bottom plate 1. The lower end of the rear rack 2 is coupled to the rear surface of the bottom plate 1, and the rear rack 2 has two installation grooves 2A. The seat frame 3 is rotatably attached to the upper part of the bottom plate 1.

  2-4, a resilient support device 10 is mounted in the bottom plate 1 near the front surface of the bottom plate 1 and has two elastic sheets 11, a fixed sheet 12, an adjustment component 13, and a support base 14. . The elastic sheets 11 are mounted in the bottom plate 1 and are parallel to each other, and each one of the elastic sheets 11 has a front end 111 and a rear end 112. The rear end 112 of the elastic sheet 11 is coupled to the rear rack 2 and mounted in the installation groove 2A. The fixed sheet 12 is positioned in the bottom plate 1 and is firmly attached on the front end 111 of the elastic sheet 11.

  The adjustment component 13 is attached below the elastic sheet 11 and includes an adjustment rod 131, a turning knob 132, and a transmission rod 133. The adjustment rod 131 is pivotally mounted in the bottom plate 1 in the vicinity of the fixed sheet 12. The turning knob 132 is attached so as to penetrate the side surface of the bottom plate 1, and is coupled to the adjusting rod 131 to rotate the adjusting rod 131. The transmission rod 133 is mounted in the bottom plate 1 so as to be pivotable in the vertical direction and engages with the adjustment rod 131. In a preferred embodiment, the adjustment rod 131 has a worm and the transmission rod 133 has a worm wheel. Since the worm of the adjustment rod 131 is engaged with the worm wheel of the transmission rod 133, the transmission rod 133 is rotated without deviation by the adjustment rod 131.

  Referring to FIGS. 3, 4, and 7, the support base 14 is attached under the elastic sheet 11 and contacts two bottom surfaces of the elastic sheet 11, and the support base 14 extends vertically in the bottom plate 1. It is movable and is driven by an adjustment component 13 to change the position of contact with the elastic sheet 11. The support base 14 has a screw hole 141, two lumps 142, and two flanges 143. The screw hole 141 is formed so as to penetrate the center of the support base 14, and the transmission rod 133 is screwed into the screw hole 141. The two lumps 142 have an arc shape, extend from the upper surface of the support base 14, and come into contact with the elastic sheet 11. The two flanges 143 are formed on the bottom surface of the support base 14. The collar portion 143 may be a groove or a protruding bar.

  5 and 6, when turning the turning knob 132 and the adjusting rod 132, the transmission rod 133 is also turned. Due to the screwed connection between the support base 14 and the transmission rod 133, the support base 14 moves along the transmission rod 133, thereby changing the contact position between the elastic sheet 11 and the mass 142. Therefore, the elasticity between the rear rack 2 and the bottom plate 1 can be changed.

  With reference to FIGS. 1, 2, and 8, a tilting device 20 is coupled to the bottom plate 1 and has a pivoting component 21, a transmission base 22, and two fastening members 23.

  Still referring to FIGS. 1, 8, and 9, the pivot component 21 has two pivot arms 211, two mortises 212, and two positioning sheets 213. Two pivot arms 211 are coupled to the two opposite sides of the bottom plate 1. Each of the two mortises 212 is formed so as to penetrate the pivot arm 211. The pivot arm 211 is pivotally coupled to the bottom plate 1 and rotates around the mortise 212. The two positioning sheets 213 protrude from the two outer surfaces of the pivot arm 212. Referring to FIG. 1, the handrail component 60 is securely mounted on one of the positioning sheets 213. A mounting base 214 is mounted between the pivot arms 211 and coupled to the rear rack 2. A plurality of insertion slots 215 are respectively formed on the two inner surfaces of the pivot arm 211 and are symmetrical to each other. The insertion slots 215 are arranged in a sector, and in a preferred embodiment, the pivot component 21 has four insertion slots 215 formed on each of the pivot arms 211.

  8 to 10, the transmission base 22 is attached to the center of the bottom plate 1 and is symmetrical. The transmission base 22 includes two guide portions 221, two cylinders 222, a through groove 223, two expansion springs 224, and a push spring 225. The guide portion 221 is formed on the bottom of the transmission base 22, and the transmission base 22 can be moved in a straight line through the bottom plate 1 by the guide portion 221. The two cylinders 222 extend from the two bottom surfaces of the transmission base 22. The through groove 223 is formed between the guide portions 221 so as to penetrate the transmission base 22. The two expansion springs 224 are coupled to the two front ends of the transmission base 22 and the bottom plate 1. The push spring 225 is coupled to the rear end of the transmission base 22 and the mounting base 214 of the pivot component 21. Since the rigidity of the push spring 225 is larger than the rigidity of the expansion spring 224, the transmission base 22 is moved forward by the push spring 225, and the tension component 226 is firmly attached in the through groove 223 of the transmission base 22. One end of the tension component 226 is positioned at the front end of the through groove 223, and the tension component 226 extends behind the mounting base 214 and is coupled to the knob. By pulling on the knob, the transmission pedestal 22 can be pulled backwards by the tension component 226.

  With reference to FIGS. 8, 9, and 13, the fastening member 23 is mounted symmetrically between both sides of the transmission base 22 and the pivot arm 211. Each fastening member 23 has a rotation hole 231, an inclined hole 232, a horizontal hole 233, and a fastening sheet 234. The rotation hole is formed so as to penetrate the front end of the fastening member 23. The inclined hole 232 is formed behind the rotation hole 231 so as to penetrate the fastening member 23, the front end of the inclined hole 232 is positioned away from the pivot arm 211, and the rear end of the inclined hole 232 is pivoted. It is positioned near the moving arm 211. The horizontal hole 233 is formed behind the rear end of the inclined hole 232, and the fastening sheet 234 extends from the outer surface of the fastening member 23.

  Referring to FIGS. 8, 11, and 12, since the bottom plate 1 has two shafts 1 </ b> C mounted in the rotation holes 231 of the fastening member 23, the fastening member 23 can be rotated and two spacing rods can be rotated. 1B is movably mounted in the horizontal holes 233, respectively. The cylinder 222 of the transmission base 22 is movably mounted in the inclined hole 232, and the fastening sheet 234 of the fastening member 23 corresponds to the insertion slot 215 of the pivot component 21.

  With reference to FIGS. 8 and 9, when no external force is applied to the tension component 226, the transmission base 22 moves forward and is pushed by the push spring 225. At this moment, each cylinder 222 of the transmission base 22 is positioned in the front end of the inclined hole 232 and the fastening member 23 is rotated toward the pivot arm 211, so that the fastening sheet 234 is placed in one of the insertion slots 215. Attached to. Since the relative angle between the pivoting component 21 and the bottom plate 1 is fixed, the rear rack 2 has a specific rearward tilt angle with respect to the bottom plate 1.

  In order to adjust the rear rack 2 to a particular rear tilt angle, the tension component 226 is pulled to move the transmission base 22 rearward. The cylinder 222 of the transmission base 22 is moved from the front end to the rear end of the inclined hole 232, and the fastening sheet 234 is separated from one of the insertion slots 215. At this moment, the rear rack 2 and the pivot arm 212 are rotated around the mortise 212, the rear rack 2 is adjusted to a specific rearward tilt angle, and then the tension component 226 is released. The transmission pedestal 22 is repositioned by the expansion spring 224 and the push spring 225, and the fastening sheet 234 is mounted in another insertion slot 215 with a different rearward inclination angle.

  Referring to FIGS. 1 and 14, a housing groove 1 </ b> A is formed in the upper surface of the bottom plate 1 on the front surface of the bottom plate 1. The seat frame 3 is rotatably attached to the upper portion of the bottom plate 1 and has a front end and a bottom surface.

  The adjustment device 30 is mounted between the seat frame 3 and the bottom plate 1 and has a rear pivot component 40 and a front adjustment component 50. Referring to FIGS. 14 and 15, the rear pivot component 40 is attached between the seat frame 3 and the bottom plate 1 at the rear end of the bottom plate structure. The rear pivot component 40 has two upper pivot holders 41, two lower pivot holders 42, and two pivot pins 43. The upper pivot holder 41 is mounted on the bottom surface of the seat frame 3 with a gap. The lower pivot holders 42 are mounted on the upper surface of the bottom plate 1 and are respectively coupled to the upper pivot holder 41. The pivot pins 43 are pivotally coupled to the upper pivot holder 41 and the lower pivot holder 42, respectively, to allow the seat frame 3 to rotate relative to the bottom plate 1.

  The front adjustment component 50 is attached between the seat frame 3 and the bottom plate 1 at the front end of the bottom plate structure, and has a positioning frame 51, a holding bracket 52, a sliding unit 53, a repositioning block 54, and a positioning block 55. The positioning frame 51 is hollow and has a positioning sheet 511 formed on the rear surface of the positioning frame 51. The positioning sheet 511 is firmly attached in the housing groove 1A of the bottom plate 1 in order to firmly hold the positioning frame 51 by the bottom plate 1.

  The holding bracket 52 is coupled to the positioning frame 51 and is firmly attached in the receiving groove 1 </ b> A of the bottom plate 1. Referring to FIGS. 15, 16, and 18, the holding bracket 52 includes two panels 521 protruding from two opposite ends of the holding bracket 52, and formed between the rear surface of the holding bracket 52 and between the panels 521. And two restriction slots 523 formed on the rear surface of the retaining bracket 52 on two opposite sides of the sawtooth portion 522.

  17 and 18, a sliding unit 53 is mounted in the positioning frame 51 so as to face the holding bracket 52 between the panels 521, and includes a pivot rod 531, a movement groove 532, a vertical groove 533, An inclined groove 534 and a rotating rod 535 are provided. The pivot rod 531 is formed on the upper end of the sliding unit 53, protrudes from the upper end, and is pivotally coupled to the seat frame 3. The moving groove 532 is formed so as to penetrate the sliding unit 53, and faces the sawtooth portion 522 of the holding bracket 52. The vertical groove 533 is formed in the sliding unit 53 above the moving groove 532 and communicates with the moving groove 532. The inclined groove 534 is a recess on the inner surface of the moving groove 532. The rotating rod 535 is mounted in the sliding unit 53 and positioned in the moving groove 532.

  Referring to FIGS. 17 to 19, the repositioning block 54 is movably mounted in the moving groove 532 of the sliding unit 53, and includes a protrusion 541, two lumps 542, two threaded portions 543, a flange 544, And two resilient elements 545. The protrusion 541 is formed on the rear end of the repositioning block 54, contacts the vertical groove 533, and is limited by the vertical groove 533. Then, the repositioning block 54 can be moved only in the vertical direction with respect to the sliding unit 53. The mass 542 protrudes from two opposite sides on the guide end of the repositioning block 54 and faces the holding bracket 52. Threaded portions 543 are each formed on the mass 542. A flange 544 is formed on the guide end of the repositioning block 54 under the mass 542 and protrudes from the guide end and faces the holding bracket 52. Each resilient element 545 is mounted on the outer surface of the repositioning block 54 perpendicular to the threaded portion 543.

  The positioning block 55 is pivotally mounted in the moving groove 532 under the repositioning block 54 by being mounted around the rotating rod 535 of the sliding unit 53, and is pressed against the repositioning block 54 to position the positioning hole. 551, an engagement recess 552, and a plurality of engagement teeth 553. The positioning hole 551 is formed in the side surface of the positioning block 55. The positioning block 55 has a torsion spring 554, which is mounted in the moving groove 532, mounted around the rotating rod 535, and has both ends. One end of the torsion spring 554 is attached in the positioning hole 551, and the other end of the torsion spring 554 is attached in the inclined groove 534 and pressed against the inner surface of the inclined groove 534. The engagement recess 552 is formed on the positioning block 55 and faces the moving groove 532 of the sliding unit 53. The engaging teeth 553 are formed on the positioning block 55 and engage with the sawtooth-shaped part 522 of the holding bracket 52.

  Thus, the repositioning block 54 can be moved vertically along the restriction slot 523 and the vertical groove 533. In order to maintain the movement stability of the repositioning block 54, each resilient element 545 abuts on the two inner walls of the restriction slot 523.

  Referring to FIGS. 1, 19, and 20, when adjusting the forward inclination angle of the bottom plate structure of the chair, the seat frame 3 is pulled upward by an external force so that it is rotated relative to the bottom plate 1 by the rear pivoting component 40. It is done. At this time, the engaging teeth 553 engage with the sawtooth-shaped portion 522. Therefore, the sliding unit 53 can be moved upward with respect to the holding bracket 52. The positioning block 55 enters a swing state and is pushed by the flange 544 to compress the torsion spring 554. Then, the engaging teeth 553 are separated from the sawtooth-shaped portion 522. After the sliding unit 53 has been moved to the desired angle, the pulling force of the sliding unit 53 is stopped and the positioning block 55 can be pressed by the torsion spring 554, so that the engaging teeth 553 are again sawtooth-shaped portions 522. And the desired forward tilt angle of the seat frame 3 relative to the bottom plate 1 is adjusted.

  When the sliding unit 53 needs to be lowered, the seat frame 3 is moved to approach a certain level of state. The sliding unit 53 is further pulled upward by an external force, and the positioning block 55 is moved upward together with the sliding unit 53. The flange 544 of the repositioning block 54 pushes the positioning block 55 and forces the positioning block 55 to swing relative to the rotating rod 535 so that the engaging teeth are disengaged from the sawtooth-shaped portion 522. . At this time, the seat frame 3 can be pushed down and rotated relative to the bottom plate 1 by the rear pivoting component 40. When the positioning block 55 is moved downward together with the sliding unit 53, the repositioning block 54 is similarly moved downward, but the contact force of the repositioning block 54 is gradually smaller than the twisting force of the torsion spring 554. . Therefore, since the engaging teeth 553 of the positioning block 55 are engaged with the saw-toothed portion 522 again, the forward inclination angle of the seat frame 3 is adjusted again and fixed.

  With the elastic support device 10 and the tilting device 20 of the present invention, the elasticity between the rear rack 2 and the bottom plate 1 can be adjusted for different demands and different users, so that the rear of the rear rack 2 The tilt angle can be adjusted according to user requirements. The forward tilt angle of the seat frame 3 can be adjusted by using the rear pivot component 40 and the front adjustment component 50 of the adjustment device 30. Therefore, the seat frame 3 can satisfy the needs of different users with different body shapes or different usage requirements by adjusting the forward tilt angle of the seat frame.

  The disclosure is merely exemplary, even though numerous features and advantages of the present invention have been set forth in the foregoing description, together with details of the structure and features of the invention. Changes in details, particularly in matters such as shape, size, arrangement of parts, etc., may be made within the principles of the invention so long as indicated by the broad and common meaning of the terms expressing the appended claims. it can.

Claims (18)

The bottom plate structure of the chair,
The bottom plate,
A rear rack pivotally coupled to the bottom plate;
A seat frame mounted on the bottom plate in front of the rear rack;
With
The bottom plate is
A resilient support device,
A tilt device;
An adjustment device;
Have
The resilient support device is:
At least one elastic sheet mounted in the bottom plate;
An adjustment component mounted in the bottom plate under the elastic sheet;
A support base movably coupled to the adjustment component;
Including
A front end of the elastic sheet is firmly coupled in the bottom plate, and a rear end of the elastic sheet is coupled to the rear rack in the bottom plate;
The support base is positioned under the elastic sheet and contacts the elastic sheet;
The tilt device is
A pivoting component coupled to the rear rack;
A transmission base attached to the center of the bottom plate;
Two fastening members coupled to both sides in the bottom plate;
Including
The pivot component is
Two pivot arms pivotally coupled to the bottom plate and securely attached to the rear rack;
A plurality of insertion slots arranged in a sector so as to be opposed to the two inner surfaces of the pivot arm;
Have
The transmission pedestal is
Two cylinders extending from two bottom surfaces of the transmission base;
Two guiding portions formed on the bottom of the transmission base;
A tensile component coupled to the transmission pedestal;
Have
The two fastening members are:
Two inclined holes respectively attached to penetrate the cylinder of the transmission base;
Two fastening sheets formed on a rear end of the fastening member and fastened in the insertion slot;
Have
The adjustment device comprises:
A rear pivoting component mounted on a rear end of the seat frame and the bottom plate;
And a front adjustment component mounted on a front end of the seat frame and the bottom plate and used to adjust a forward tilt angle of the seat frame relative to the bottom plate. The transmission pedestal is
Two expansion springs respectively coupled to the front end of the transmission base and the front end of the bottom plate;
A push spring coupled to a rear end of the transmission base;
Have
The bottom plate structure of the chair according to claim 1, wherein the rigidity of the push spring is larger than the rigidity of the expansion spring. Each one of the fastening members has a horizontal hole formed behind the rear end of the inclined hole,
The fastening sheet extends from the outer surface of the horizontal hole of the fastening member,
The chair bottom plate structure according to claim 1, wherein the bottom plate has two spacing rods movably mounted in the horizontal hole. Each one of the fastening members has a horizontal hole formed behind the rear end of the inclined hole,
The fastening sheet extends from the outer surface of the horizontal hole of the fastening member,
The bottom plate structure of the chair according to claim 2, wherein the bottom plate has two spacing rods movably mounted in the horizontal hole. The transmission pedestal has a through groove formed so as to penetrate the transmission pedestal between the guide portions,
The chair bottom plate structure according to claim 1, wherein one end of the tension component is positioned at a front end of the through groove. The transmission pedestal has a through groove formed so as to penetrate the transmission pedestal between the guide portions,
The bottom plate structure of the chair according to claim 2, wherein one end of the tension component is positioned at a front end of the through groove. The pivot component is
Two positioning sheets projecting from the two outer surfaces of the pivot arm;
A mounting base mounted between the pivot arms and coupled to the rear rack;
Have
The chair bottom plate structure according to claim 1, wherein the chair bottom plate structure has a handrail component mounted securely on one of the positioning sheets. The pivot component is
Two positioning sheets projecting from the two outer surfaces of the pivot arm;
A mounting base mounted between the pivot arms and coupled to the rear rack;
Have
The chair bottom plate structure according to claim 2, wherein the chair bottom plate structure has a handrail component mounted firmly on one of the positioning sheets. The bottom plate has an accommodation groove formed in the upper surface of the bottom plate at the front surface of the bottom plate,
The front adjustment component of the adjustment device is:
A positioning frame mounted in the bottom plate;
A retaining bracket coupled to the positioning frame and securely mounted in the receiving groove of the bottom plate;
A sliding unit mounted in the positioning frame so as to face the holding bracket and pivotally coupled to the seat frame;
A repositioning block mounted in the sliding unit;
A positioning block pivotally mounted in the sliding unit under the repositioning block;
The bottom plate structure of the chair according to claim 1, comprising: The holding bracket has a sawtooth portion formed on the rear surface of the holding bracket;
The sliding unit has a rotating rod mounted in the sliding unit;
The positioning block is pivotally mounted in the sliding unit by the rotating rod;
The positioning block is
A torsion spring attached around the rotating rod;
A plurality of engaging teeth formed on the positioning block and engaged with the sawtooth-shaped portion of the holding bracket;
An engagement recess formed on the positioning block and facing the sliding unit;
Have
The torsion spring has both ends, one end of the torsion spring is mounted in the positioning block, and the other end of the torsion spring is mounted in the sliding unit;
The repositioning block is movably mounted in the sliding unit;
The bottom plate structure of the chair according to claim 9, wherein the repositioning block has a flange protruding from a guide end of the repositioning block and facing the holding bracket. The sliding unit is
A moving groove formed on the sliding unit and facing the sawtooth portion of the holding bracket;
A vertical groove formed in the sliding unit above the moving groove;
Have
The repositioning block is:
A protrusion formed on a rear end of the repositioning block and abutting the vertical groove and limited by the vertical groove;
Two masses projecting from two opposite sides on the guide end of the repositioning block and facing the retaining bracket;
Have
The holding bracket is
Two restricting slots formed on the rear surface of the holding bracket and provided on both sides of the sawtooth-shaped portion;
The bottom plate structure of the chair according to claim 10, wherein the restriction slot corresponds in position to the mass. The repositioning block is:
Two threaded portions respectively formed on the mass;
Two resilient elements each mounted on the outer surface of the mass perpendicular to the threaded portion;
Have
The chair baseplate structure of claim 11, wherein each resilient element abuts an inner wall of the restriction slot. The rear pivot component is
Two upper pivot holders mounted on the bottom surface of the seat frame at an interval;
Two lower pivot holders mounted on the upper surface of the bottom plate and respectively coupled to the upper pivot holder;
Two pivot pins each pivotably coupled to the upper pivot holder and the lower pivot holder;
The bottom plate structure of the chair according to claim 9, comprising: The rear pivot component is
Two upper pivot holders mounted on the bottom surface of the seat frame at an interval;
Two lower pivot holders mounted on the upper surface of the bottom plate and respectively coupled to the upper pivot holder;
Two pivot pins each pivotably coupled to the upper pivot holder and the lower pivot holder;
The bottom plate structure of the chair according to claim 10, comprising: The adjustment component is
An adjustment rod pivotally mounted in the bottom plate;
A transmission rod vertically and pivotally mounted in the bottom plate and engaged with the adjustment rod;
The bottom plate structure of the chair according to claim 1, comprising: The adjustment component has a turning knob attached to the side of the bottom plate and coupled to the adjustment rod;
The adjusting rod has a worm;
The transmission rod has a worm wheel, the worm of the adjustment rod engages the worm wheel of the transmission rod;
The chair base plate structure according to claim 15, wherein the support base has a screw hole formed so as to penetrate a center of the support base and into which the transmission rod is screwed. The resilient support device comprises two elastic sheets parallel to each other;
The support base is
Each of two masses extending from the upper surface of the support base and contacting the elastic sheet;
Two flanges formed on the bottom surface of the support base;
The bottom plate structure of the chair according to claim 15, comprising: The resilient support device comprises two elastic sheets parallel to each other;
The support base is
Each of two masses extending from the upper surface of the support base and contacting the elastic sheet;
Two flanges formed on the bottom surface of the support base;
The bottom plate structure of the chair according to claim 16, comprising:

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