Gear linkage folding wheelchair chair structure

Abstract

The utility model relates to a crutch chair structure of gear linkage folding and unfolding, which comprises a lower pivot seat, three lower supporting feet pivotally connected to the lower pivot seat, three upper supporting arms pivotally connected to the upper pivot seat, two supporting tubes and a main supporting tube, wherein the main supporting tube has a sliding seat supporting a main surface, and the two supporting tubes support two side surfaces; the lower supporting feet are provided with top gears, the upper supporting arms are provided with bottom gears, the top gears are engaged with the bottom gears, the sliding seat is raised or lowered, the main surface is synchronously raised or lowered, the two side surfaces are synchronously turned down or up, and the three upper supporting arms are synchronously closed or unfolded; the bottom gears drive the top gears, and the three lower supporting feet are synchronously closed or unfolded.

Description

[Technical Field]

[0001] This utility model relates to a cane chair structure with gear linkage for folding and unfolding, and more particularly to a cane chair structure with gear linkage for folding and unfolding, which is different from the existing method of relying on connecting rods to link the three lower support legs and three upper support arms for unfolding. The cane chair structure with gear linkage provides a labor-saving and easy and smooth folding or unfolding. [Background Technology]

[0002] Canes are tools to assist people with mobility impairments. For those with poor walking stability, canes are the preferred mobility aid, helping to maintain balance while standing, reducing the chance of falls, and preventing falls while walking. Therefore, canes are simple and easy to carry. They are not only used for walking on flat ground, but also by hikers. As canes have become a common tool, professionals have developed cane chairs. Cane chairs are multi-functional assistive tools. When carried, they can be used as canes to help people stand, walk, and maintain balance. When a rest is needed, the cane chair can be easily unfolded and used as a seat. Cane chairs are suitable for use outdoors, while traveling, queuing, shopping, relaxing, fishing, and other occasions where long waiting or resting is required. Cane chairs are usually designed to be lightweight, easy to store and carry, and do not take up much space, thus they are widely popular.

[0003] Currently, the structural components of most cane chairs on the market mainly include three lower support legs, two upper support rods, a main rod, a seat, a slide, and a pivot. The three lower support legs are pivotally connected to the bottom of the pivot, allowing them to be closed or unfolded into a tripod shape. The two upper support rods and the slide are pivotally connected to the top of the pivot. The main rod passes through the slide. The two upper support rods and the main rod can be closed or unfolded into an inverted tripod shape. The seat is composed of three panels. The tops of the two upper support rods and the slide each support the seat (three panels). The slide can rise or fall and be positioned according to the main rod. When unfolded, the slide is lowered, and the three upper support rods open the three panels to form a flat seat for the person to sit on. The three lower support legs and three upper support rods are all open, with the three lower support legs contacting the ground to support the overall weight. When folded... When the sliding seat is raised, the middle panel rises relative to the two side panels, and the side panels fold inward. This causes the three lower support legs and three upper support rods to close together. To move the two upper support rods and the main rod, several connecting rods are required to pivot between each other. Similarly, to move the three lower support legs, several connecting rods are required to pivot between each other. The structure is complex and varied, with many components, making assembly time-consuming and costly. During operation, it is easy to get fingers pinched by several connecting rods, causing injury. This is very troublesome for consumers. Furthermore, the connecting rods between the three lower support legs or the three upper support rods create resistance when folding or unfolding. Therefore, it takes a lot of force to fold or unfold the cane chair, which is inconvenient for the elderly or women and children. It is impossible to fold or unfold smoothly in one go. In addition, existing cane chairs often use studs to lock and fix them after folding or unfolding, which may loosen and slip, posing a safety hazard.

[0004] The above problems clearly need to be improved. [Utility Model Content]

[0005] This utility model discloses a gear-driven retractable cane chair structure. Its objectives are: 1. To provide a gear-driven retractable mechanism, eliminating the need for linkages between the three lower support legs and three upper support arms as in existing systems. This gear-driven mechanism allows for effortless folding and unfolding; pulling up or pressing down the slide is easy and unimpeded by traditional linkages, enabling smooth folding and unfolding. 2. To provide simple and convenient operation for unfolding and folding. Only two main actions—pressing the latch button and pulling up or pressing down the slide—are required to activate all components for unfolding or folding, without complex procedures. 3. To provide a safety design. When the latch button's pin is engaged in the lower or upper positioning hole of the main support tube, the slide will not suddenly rise or fall independently, providing a stable seat and preventing unauthorized unfolding after folding, thus eliminating the unsafe method of using studs for securing the position. 4. Without the need for multiple connecting rods, there is no risk of fingers being pinched by the rods when folding or unfolding. Furthermore, with fewer connecting rods, assembly is easier, production costs are reduced, and the weight and volume are reduced, making it easier to store, package, and transport.

[0006] To achieve the above objectives, this utility model proposes a gear-driven retractable cane chair structure, which has the following features:

[0007] A pivot seat has three rectangular slots arranged radially. The rectangular slots are at the same angle to each other. There is a baffle on the outer perimeter of each rectangular slot. Above the baffle is an upper inclined baffle, and below the baffle is a lower inclined baffle.

[0008] The three lower support legs have a flattened round top at the top, which is pivotally connected to the bottom of the rectangular groove.

[0009] There are three upper support arms. The bottom of each upper support arm is a flat round shape, which is pivotally connected to the top of a rectangular groove. Each of the two upper support arms is connected to a support tube, and a universal joint is provided on the top of the support tube. The other upper support arm is connected to a main support tube, and a handrail is connected to the top of the main support tube. There is a slide on the main support tube, which has a sliding tube and a convex circle. The main support tube and the other upper support arm can pass through the sliding tube. There is a locking button on the outside of the slide, which controls the slide to rise or fall on the main support tube.

[0010] A slide is formed by a main surface and two side surfaces pivotally connected together. The convex circle of the slide is pivotally connected to the bottom of the main surface, and the universal joints of each support tube are pivotally connected to the bottom of each side surface.

[0011] The feature is that: the top flat circle of the three lower support legs is provided with a top gear, and the bottom flat circle of the three upper support arms is provided with a bottom gear. The top gear of the lower support leg meshes with the bottom gear of the corresponding upper support arm. With the above-mentioned structural combination, when the latch button is released and the slide of the self-supporting tube rises, the inner edge of the main surface rises and gradually turns downwards longitudinally, which in turn causes the two sides to turn downwards and gradually turn downwards laterally. Simultaneously, the three upper support arms move closer together, and the bottom gear of the upper support arm drives the top gear of the lower support leg, so that the three lower support legs move closer together and close. When the latch button is released and the slide of the self-supporting tube descends, the outer edge of the main surface rises and gradually turns upwards longitudinally, which in turn causes the two sides to turn upwards and gradually turn upwards laterally. Simultaneously, the three upper support arms unfold into an inverted tripod shape for support and unfold the seat surface. The bottom gear of the upper support arm drives the top gear of the lower support leg, so that the three lower support legs are in an unfolded tripod shape.

[0012] The top gear of the lower support foot is a double-parallel gear, and the bottom gear of the corresponding upper support arm is also a double-parallel gear.

[0013] The slide has a recessed space on its outer side with two through holes. The inner surface of the latch button has an obtuse-angled protrusion and a protruding locking pin. The obtuse-angled protrusion contacts the inner wall of the recessed space. The latch button has an inner hole, a pivot pin, and a torsion spring. The pivot pin passes through the inner hole and the two through holes in the recessed space, positioning the latch button in the recessed space of the slide. The outer side of the main support tube has an upper positioning hole and a lower positioning hole. The locking pin of the latch button can be inserted into or released from the upper positioning hole or the lower positioning hole. The upper surface of the latch button has several anti-slip grooves. The slide tube of the slide has a pair of lugs for the fingers to pull up or press down.

[0014] The lower support leg has a flat, round top pivot connected to the bottom of a rectangular groove, with a lower column passing through as a pivot. The upper support arm has a flat, round bottom pivot connected to the top of a rectangular groove, with an upper column passing through as a pivot.

[0015] The main surface of the seat has several main recesses and several main protruding tubes on both sides, and several side protruding tubes and several side recesses on opposite sides, each of which is pivotally connected by a column.

[0016] The support tube is fitted with a cap, and a base plate is positioned inside the cap. The base plate extends out of the top of the cap and is pivotally connected to the universal joint. A fixing plate is provided on the bottom side of the seat surface, and the top of the universal joint is fixed by the fixing plate.

[0017] The main surface has a pair of pivot ears below it. The pivot ears are used for the convex round of the slide. Each pivot ear is provided with a reinforcing piece and a small post is used to pivot the pair of pivot ears and the convex round.

[0018] Among them, the support tube and the main support tube are both triangular hollow tubes, the three upper support arms are also triangular prisms with textured surfaces and two positioning holes, and the three lower support legs are all triangular hollow tubes.

[0019] The advantages and beneficial effects of this utility model are as follows: It uses gear meshing for coordinated folding and unfolding, eliminating the need for connecting rods to link the three lower support legs and three upper support arms. The gear linkage provides effortless folding and unfolding; pulling up or pressing down the slide is effortless, without the resistance of traditional connecting rods, allowing for smooth folding and unfolding. Operation is simple and convenient; just pressing the latch button and pulling up or pressing down the slide will activate all components for folding or unfolding, without complicated procedures. When the latch button's pin is inserted into the lower or upper positioning hole of the main support tube, the slide will not suddenly rise or fall on its own, providing a stable ride and preventing accidental unfolding after folding, thus eliminating the unsafe method of using studs for positioning. Without multiple connecting rods, there is no risk of fingers being pinched during folding or unfolding. Furthermore, fewer connecting rods simplify assembly, reduce production costs, and decrease weight and size, facilitating storage, packaging, and transportation. [Attached Image Description]

[0020] Figure 1 This is a three-dimensional schematic diagram of the unfolded present invention.

[0021] Figure 2 This is a three-dimensional exploded view of the main support tube and slide of this utility model.

[0022] Figure 3 This is a three-dimensional exploded view of the pivot seat, three upper support arms, three lower support feet, and seat surface of this utility model.

[0023] Figure 4 This is a three-dimensional schematic diagram of the bottom of the seat surface of this utility model.

[0024] Figure 5 This is a three-dimensional schematic diagram of the meshing of the bottom gear and the top gear of this utility model.

[0025] Figure 6 This is a planar schematic diagram showing the meshing of the bottom gear and the top gear of this utility model.

[0026] Figure 7 This is a cross-sectional schematic diagram of the locking pin of the locking button of this utility model being embedded in the lower positioning hole of the main support tube.

[0027] Figure 8 This is a three-dimensional schematic diagram of the present invention in a quarter-folded state.

[0028] Figure 9 This is a three-dimensional schematic diagram of the present invention in a folded-in half state.

[0029] Figure 10 This is a three-dimensional schematic diagram of the utility model in its three-quarters folded state.

[0030] Figure 11 This is a three-dimensional schematic diagram of the utility model after it has been folded.

[0031] Figure 12 This is a plan view of the folded portion of this utility model.

[0032] Figure 13 This is a cross-sectional schematic diagram of the locking pin of the locking button of this utility model embedded in the upper positioning hole of the main support tube.

[0033] The labels in the diagram are explained as follows:

[0034] 10 Pivot seat 20 Lower support foot 30 Upper support arm 40 Slide seat

[0035] 50 Seat surface 11 Rectangular groove 111 Baffle wall 112 Upper sloping flange

[0036] 113 Lower oblique flange 201 Lower column 21 Top gear 301 Upper column

[0037] 31 Bottom gear, 32 Support tube, 321 Universal joint, 300 Upper support arm

[0038] 33 Main support tube; 34 Handrail; 41 Sliding tube; 42 Convex circle

[0039] 43. Locking button; 44. Recessed space; 441. Perforation; 431. Obtuse-angled protrusion.

[0040] 432 Snap pin; 435 Inner hole; 433 Pivot pin; 434 Torsion spring

[0041] 302 Texture, 303 Positioning Hole, 331 Upper Positioning Hole, 332 Lower Positioning Hole

[0042] 436 Anti-slip texture 45 Lug 51 Main surface 52 Side surface

[0043] 511 Main notch 512 Main protruding tube 521 Side protruding tube 522 Side notch

[0044] 53 Column body 513 Pivot lug 514 Reinforcing plate 515 Small column

[0045] 322 Cap, 323 Substrate, 523 Fixing Plate

Detailed Implementation Methods

[0046] This utility model discloses a gear-driven retractable cane chair structure, such as... Figure 1-6As shown, it has a pivot seat 10, three lower support legs 20, three upper support arms 30, a slide seat 40, and a seat surface 50. The pivot seat 10 has three radially arranged rectangular slots 11, which are distributed radially. The included angles between the rectangular slots 11 are the same, and there is a baffle wall 111 on the outer periphery of each rectangular slot 11. Above the baffle wall 111 is an upper inclined baffle 112, and below the baffle wall 111 is a lower inclined baffle 113. The top of the lower support leg 20 is... A flat, round top is pivotally connected to the bottom of a rectangular groove 11. The flat, round top of the lower support leg 20 is pivotally connected to the bottom of the rectangular groove 11 via a lower column 201. A top gear 21, a double-parallel gear, is arranged around the flat, round top. The bottom of the upper support arm 30 is a flat, round bottom, pivotally connected to the top of the rectangular groove 11. The flat, round bottom of the upper support arm 30 is pivotally connected to the top of the rectangular groove 11 via an upper column 301. The flat, round bottom... The ring is equipped with a bottom gear 31, which is also a double-parallel gear. The top gear 21 of the lower support leg 20 meshes with the corresponding bottom gear 31 of the upper support arm 30. When the upper support arm 30 swings in one direction, due to the meshing of the bottom gear 31 and the top gear 21, the top gear 21 and the bottom gear 31 have the same number of teeth and size, and the corresponding lower support leg 20 will also swing equidistantly in the same direction. Each of the two upper support arms 30 is connected to a support tube 32. The upper support arm 300 is provided with a universal joint 321. A main support tube 33 is connected above the other upper support arm 300. A handrail 34 is connected to the top of the main support tube 33. A slide 40 is fitted on the main support tube 33. The slide 40 is provided with a sliding tube 41 and a convex circle 42. The main support tube 33 and the other upper support arm 300 are inserted into the sliding tube 41. There is a locking button 43 on the outside of the slide 41. The locking button 43 controls the slide 40 to rise or fall on the main support tube 33. There is a recessed space 44 on the outside of the slide 40 (e.g., ...). Figure 7 (As shown), a latching button 43 is pivotally connected to a recessed space 44, which has two through holes 441. The inner surface of the latching button 43 has an obtuse-angled protrusion 431 and a protruding latch 432. The obtuse-angled protrusion 431 contacts the inner wall of the recessed space 44, allowing the latching button 43 to move in a seesaw motion around the obtuse-angled protrusion 431. The latching button 43 has an inner hole 435, a pivot 433, and a torsion spring 434. The pivot 433 passes through the inner hole 435 and the recessed space 44 of the latching button 43. The two perforations 441 of the space 44 position the latch button 43 in the recessed space 44 of the slide 40. The torsion spring 434 is sleeved on the pivot post 433, so that the latch post 432 below the unpressed latch button 43 protrudes from the inner wall of the recessed space 44. When the top of the latch button 43 is pressed, the bottom of the latch button 43 does not protrude from the inner wall of the recessed space 44. When the finger is released from the press, the torsion spring 434 restores the latch button 43 to its original state (the top of the latch button 43 is away from the inner wall of the recessed space 44).

[0047] Both the support tube 32 and the main support tube 33 are triangular hollow tubes, which are lightweight and provide maximum support strength while enhancing rigidity. The upper support arms 30 and 300 are triangular solid prisms with textured surfaces 302 and two positioning holes 303. The textured surfaces 302 increase the frictional bonding force with the support tube 32 and the main support tube 33, and the positioning holes 303 are for engaging with the support tube 32 and the main support tube 33. The three lower support legs 20 are also triangular hollow tubes, which are lightweight and provide maximum support strength while enhancing rigidity. The outer side of the main support tube 33 has an upper positioning hole 331 and a lower positioning hole 332. The locking pin 432 of the locking button 43 can be inserted into or disengaged from the upper positioning hole 331 or the lower positioning hole 332. The upper surface of the button 43 has several anti-slip grooves 436. The slide tube 41 of the slide block 40 has a pair of lugs 45 for the fingers to pull up or press down on the slide block 40. The seat surface 50 is formed by a main surface 51 and two side surfaces 52 pivotally connected. The main surface 51 of the seat surface 50 has several main recesses 511 and several main protruding tubes 512 forming a grid on both sides, and the two side surfaces 52 have several side protruding tubes 521 and several side recesses 522 forming a grid on opposite sides. Each is pivotally connected by a column 53 that passes through each main protruding tube 512 and each side protruding tube 521, thus pivotally connecting the main surface 51 to the two side surfaces 52. The convex circle 42 of the slide block 40 is pivotally connected below the main surface 51. A pair of pivot lugs 513 (e.g., ...) are provided below the main surface 51. Figure 4 As shown), pivot ears 513 are pivotally connected to the convex circle 42 of the slide 40. Each pivot ear 513 is provided with a reinforcing piece 514. A small post 515 pivotally connects the pair of pivot ears 513 and the convex circle 42. The universal joints 321 of each support tube 32 are pivotally connected to the lower part of each side 52. A cap 322 is fitted on the top of the support tube 32. A base plate 323 is positioned inside the cap 322. The base plate 323 extends out of the top of the cap 322 and is pivotally connected to the universal joint 321. A fixing plate 523 is provided at the bottom of the side 52 of the seat surface 50. The universal joint 32 The top of 1 is fixed by the fixing plate 523. The pivot lug 513 below the main surface 51 is positioned close to the main support tube 33, and the universal joint 321 at the bottom of the side 52 is positioned away from the main support tube 33, so that the positioning pivot point at the bottom of the main surface 51 and the positioning pivot points at the bottom of the two side 52 form a triangular distribution. When one side of the main surface 51 is lifted upward by the slide 40, the main surface 51 gradually tilts, and the two side 52 will turn downward. When the slide 40 is lifted to a fixed point, the main surface 51 tends to turn from tilted to upright (making a longitudinal turn downward, as shown). Figure 8-11As shown), the two sides 52 turn downwards and gradually turn laterally downwards, and the three upper support arms 30 will also gradually close and converge. Because the top gear 21 of the lower support leg 20 meshes with the bottom gear 31 of the corresponding upper support arm 32, and the bottom gear 31 of the upper support arm 32 is a double bottom gear 31, it also meshes with the adjacent bottom gear 31. The movement of one upper support arm 32 will affect the other adjacent upper support arm 32. When the upper support arm 30 swings to one side, because the bottom gear 31 meshes with the top gear 21, the corresponding lower support arm 30 will also move. The support legs 20 will also swing at equal distances in the same direction. The top gear 21 of the lower support leg 20 is a double top gear 21, which meshes with the other adjacent top gear 21. The movement of one lower support leg 20 will affect the other adjacent lower support leg 20. That is, the movement of the upper support arm 32 will affect the left and right upper support arms 32 to retract, and affect the lower support leg 20 below to retract. When the three upper support arms 30 (including the two support tubes 32 and the main support tube 33) gradually close and retract, the three lower support legs 20 will also gradually close and retract simultaneously.

[0048] Based on the above structural combination, the operation and collection are as follows: Figure 1 , 2 As shown in Figure 7, when the anti-slip texture 436 of the latch button 43 is pressed, the latch 432 of the latch button 43 disengages from the lower positioning hole 332 of the main support tube 33. The sliding base 40 is then pulled upwards from the main support tube 33 by a finger until the latch 432 of the latch button 43 is inserted into the upper positioning hole 331 of the main support tube 33 (as shown in Figure 7). Figure 13 As shown), the inner edge of the main surface 51 rises synchronously and gradually turns downwards longitudinally, which in turn causes the two side surfaces 52 to turn downwards and gradually turn downwards laterally, resulting in a folded seat surface 50. Because the movements of the main surface 51 and the two side surfaces 52 are synchronized, the three upper support arms 30 move closer together. The bottom gear 31 of the upper support arm 30 drives the top gear 21 of the lower support foot 20, causing the three lower support feet 20 to move closer together and close. After the entire structure is folded (as shown...), Figure 11 , 12As shown), it is convenient to carry and can be used as a cane; similarly, when the anti-slip texture 436 of the latch button 43 is pressed, the latch 432 of the latch button 43 disengages from the upper positioning hole 331 of the main support tube 33, and the sliding base 40 is pressed down on the main support tube 33 by a finger until the latch 432 of the latch button 43 is inserted into the lower positioning hole 332 of the main support tube 33, the outer edge of the main surface 51 rises simultaneously and gradually makes a vertical turn upward, which in turn causes the two side surfaces 52 to turn upward and gradually make a horizontal turn upward, and simultaneously connect The three upper support arms 30 (including two support tubes 32 and a main support tube 33) unfold into an inverted tripod shape to provide support and unfold the seat surface 50. The bottom gear 31 of the upper support arm 30 drives the top gear 21 of the lower support leg 20, so that the three lower support legs 20 are unfolded into a tripod shape. Since the seat surface 50 has been unfolded and has the three unfolded lower support legs 20, the seat surface 50 can be used for people to sit on, and can be used in various occasions such as outdoor activities, travel, queuing, shopping, fishing, etc. where long-term waiting and rest are required.

[0049] The main linkage of this utility model is that the rising or falling of the slide 40 causes the seat surface 50 to retract or expand. The seat surface 50 then links the three upper support arms 30 (including two support tubes 32 and a main support tube 33) to close or expand. The three upper support arms 30 then link the three lower support feet 20 to close or expand. The operation of unfolding or folding is simple and convenient. Only two main simple actions are required: pressing the latch button 43 and pulling or pressing the slide 40 up or down. This will trigger the unfolding or folding of all the accessories. There are no complicated operating procedures. It can be operated by the elderly or children. The pressing action is light and does not require strong force. When the latch 432 of the latch button 43 is embedded in the lower positioning hole 332 or upper positioning hole 331 of the main support tube 33, it is a safety design. The slide 40 will not suddenly rise or fall on its own, providing a stable seat for the human body. After folding, it will not unfold arbitrarily. The three upper support arms 30, when unfolded, rest against the rectangular groove 11 of the pivot seat 10. The inclined flange 112 stops and no longer moves outward, and the three lower support legs 20 also stop and no longer move outward against the lower inclined flange 113 of the rectangular groove 11 of the pivot seat 10. Therefore, the three upper support arms 30 (including the main support tube 33 and two support tubes 32) and the three lower support legs 20, once deployed, provide strong support and enhance the support for the human body. This design uses gear linkage for deployment and retraction, rather than linkage to activate the three lower support legs 20 and the three upper support legs 20. With support arm 30, the gear linkage provides effortless folding or unfolding. Pulling up or pressing down slide 40 is easy and unhindered by the force of traditional linkages, allowing for smooth folding or unfolding in one smooth motion. Furthermore, with fewer linkages, there is no risk of fingers being pinched by linkages during folding or unfolding. Also, fewer linkages make assembly easier, reduce production costs, and reduce the size after folding, making packaging easier, transportation easier, and storage more convenient.

Claims

1. A cane chair structure with gear linkage for retraction and extension, comprising: A pivot seat has three rectangular slots arranged radially. The rectangular slots are at the same angle to each other. There is a baffle on the outer perimeter of each rectangular slot. Above the baffle is an upper inclined baffle, and below the baffle is a lower inclined baffle. The three lower support legs have a flattened round top at the top, which is pivotally connected to the bottom of the rectangular groove. There are three upper support arms. The bottom of each upper support arm is a flattened round shape, which is pivotally connected to the top of a rectangular groove. Each of the two upper support arms is connected to a support tube, and a universal joint is provided on the top of the support tube. The other upper support arm is connected to a main support tube, and a handrail is connected to the top of the main support tube. There is a slide on the main support tube, which has a sliding tube and a convex circle. The main support tube and the other upper support arm can pass through the sliding tube. There is a locking button on the outside of the slide, which controls the slide to rise or fall on the main support tube. A slide is formed by a main surface and two side surfaces pivotally connected together. The convex circle of the slide is pivotally connected to the bottom of the main surface, and the universal joints of each support tube are pivotally connected to the bottom of each side surface. characterized in that The three lower support legs are equipped with top gears around their top flat circular rings, and the three upper support arms are equipped with bottom gears around their bottom flat circular rings. The top gears of the lower support legs mesh with the bottom gears of the corresponding upper support arms. When the operating slide rises or falls, the inner side of the main surface rises or falls synchronously, which in turn causes the two side surfaces to turn downwards or upwards and unfold, which in turn causes the three upper support arms to move closer or unfold. The bottom gear drives the top gear, causing the three lower support legs to move closer or unfold.

2. The gear linked folding and unfolding wheelchair chair structure according to claim 1, characterized in that: The top gear of the lower support foot is a double parallel gear, and the bottom gear of the corresponding upper support arm is also a double parallel gear.

3. The gear linked folding and unfolding wheelchair chair structure according to claim 1, wherein: The slide has a recessed space on its outer side, with two through holes. The inner surface of the latch button has an obtuse-angled protrusion and a protruding locking pin. The obtuse-angled protrusion contacts the inner wall of the recessed space. The latch button has an inner hole, a pivot pin, and a torsion spring. The pivot pin passes through the inner hole and the two through holes in the recessed space, positioning the latch button in the recessed space of the slide. The outer side of the main support tube has an upper positioning hole and a lower positioning hole. The locking pin of the latch button can be inserted into or disengaged from the upper or lower positioning hole. The upper surface of the latch button has several anti-slip grooves. The slide tube of the slide has a pair of lugs for the fingers to pull up or press down.

4. The gear linked folding and unfolding wheelchair chair structure according to claim 1, wherein: The top flat circular pivot of the lower support leg is connected to the bottom of the rectangular groove with a lower column passing through as a pivot, and the bottom flat circular pivot of the upper support arm is connected to the top of the rectangular groove with an upper column passing through as a pivot.

5. The gear linked folding and unfolding wheelchair chair structure according to claim 1, wherein: The main surface of the seat has several main recesses and several main protruding tubes on both sides, and several side protruding tubes and several side recesses on opposite sides, each of which is pivotally connected by a column.

6. The gear linked folding and unfolding wheelchair chair structure according to claim 1, wherein: A cap is fitted over the support tube, and a base plate is positioned inside the cap. The base plate extends out of the top of the cap and is pivotally connected to the universal joint. A fixing plate is provided on the bottom side of the seat surface, and the top of the universal joint is fixed by the fixing plate.

7. The gear linked folding and unfolding wheelchair chair structure according to claim 1, wherein: Below the main surface, there is a pair of pivot ears for the convex round of the slide. Each pivot ear is provided with a reinforcing piece, and a small post is used to pivot the pair of pivot ears and the convex round.

8. The gear linked folding and unfolding wheelchair chair structure according to claim 1, wherein: The support pipe and the main support pipe are all triangular hollow pipe bodies, the three upper support arms are also triangular column bodies, and the surfaces are provided with a texture and two positioning holes. The three lower support feet are all triangular hollow pipe bodies.

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