HK1213764B - Apparatus comprising a bottom part and a crawler moving mechanism - Google Patents

Description

Device including vehicle bottom part and crawler walking mechanism

This application is a divisional application of the invention patent application with application number 201210110973.1, application date April 5, 2012, priority date October 4, 2011, and name “Electric Wheelchair”.

Technical Field

The present invention relates to an electric wheelchair, in particular to an electric wheelchair with a stair climbing function and capable of safely and smoothly ascending and descending multiple stairs, ascending and descending slopes, or climbing over obstacles.

Background Art

Wheelchairs for people with limited mobility come in a variety of designs, some of which are designed to climb stairs. Most of these designs use complex wheels, a combination of mobile tracks and wheels, or other devices, combined with electronic sensors, hydraulic arms, etc., resulting in high costs. Some designs also have serious safety issues, are bulky, and very inconvenient to use. Some also require assistance from others when going up and down stairs.

Chinese Utility Model Patent No. 201079509Y discloses a crawler stair climbing chair, which includes a seat, a seat frame, wheels disposed below the seat frame, a crawler track mechanism, and an automatic balancing mechanism disposed below the seat. The crawler track mechanism is driven by an electric drive device, and the crawler track portion comprises an ascending track and a descending track, with the rear side of the descending track angled to the ground. Although this crawler stair climbing chair utilizes an automatic balancing mechanism to maintain constant seat balance, the design neglects the lever issue of the fulcrum and the force point, and the seat lacks an automatic locking mechanism. As a result, when ascending or descending stairs, the chair's center of gravity is too close to the fulcrum. If a passenger leans forward even slightly, the chair tends to tilt forward, potentially causing a rollover. Furthermore, since the track position cannot be adjusted, the chair can trip over obstacles while traveling on the ground.

Chinese Utility Model Patent No. 201316363Y discloses a wing-shaped stair climbing vehicle with a wheel and track mechanism. It utilizes a combination of a reducer and a DC motor to achieve continuous ascent. The track system includes a running track, a climbing track, and an auxiliary track. The climbing track is mounted on either side of the front frame of the stair climbing vehicle and can be controlled to rotate and retract within a certain angle range. The auxiliary track is mounted on either side of the rear frame and can also be controlled to rotate and retract within a certain angle range. While this stair climbing vehicle design allows for smooth ascending and descending stairs, its flat base means that when the vehicle is about to reach level ground, especially at the top of the steps, it can suddenly drop rapidly, potentially impacting passengers and posing a dangerous threat. Even with the front and rear auxiliary tracks, it is difficult for passengers to simultaneously maintain control of the front and rear tracks and the forward and backward travel directions. Furthermore, this stair climbing vehicle is bulky, making it extremely inconvenient to operate and manage.

When a wheelchair climbs the stairs, the body of the wheelchair tilts significantly. The aforementioned and other electric wheelchairs use movable seats to address this tilting problem. However, most of these models overlook the lever issues of fulcrum and force points, believing that simply moving the seat will solve the problem. They don't even consider locking the seat, which poses a safety risk.

When a tracked wheelchair reaches the top of a staircase, it can suddenly drop due to its center of gravity, potentially impacting and endangering passengers. Therefore, some products employ complex mechanical devices to address this issue, significantly increasing costs.

Some products are complex in design, resulting in a relatively large size, which is inconvenient whether traveling on the ground or going up and down stairs.

Summary of the Invention

In order to at least partially solve some of the problems existing in the electric wheelchairs of the prior art, the present invention provides an electric wheelchair having the following advantages:

- The electric wheelchair of the present invention has roller wheels on both sides of the bottom of the movable seat, which evenly supports the passenger's weight on the body, making the seat move more smoothly and safely;

- Equipped with an anti-reverse gear assembly and a safety lock device, the seat not only provides double safety for passengers, but also makes it more flexible and practical, making it easier for passengers to get in and out of their wheelchairs and other daily activities.

- Equipped with movable extension tracks, it can increase the distance between the wheelchair's fulcrum and the center of gravity, thereby increasing safety when going up and down stairs;

- The movable extension tracks can rotate 360 degrees and can be stored on both sides of the vehicle body, reducing the size of the wheelchair and allowing safe passage when encountering obstacles;

- The two-stage bottom design allows the wheelchair to operate smoothly and stably whether going up or down stairs;

- The movable extension track is equipped with anti-reverse gears and a safety lock device to ensure that the track is locked in the required position, greatly improving safety;

-Equipped with a compact seat balance sensing device, it has a simple structure and takes up very little space.

The above objects and advantages of the present invention can be achieved through the following features.

The electric wheelchair of the present invention comprises a movable seat portion, a body portion serving as a seat support, a seat adjustment mechanism disposed below the seat for maintaining the balance of the seat portion, a vehicle bottom portion located below the body portion, and a tracked running mechanism, wherein the tracked running mechanism comprises two sets of tracks disposed below two sides of the vehicle bottom portion, each set of tracks comprising a front track and a rear track.

The vehicle bottom portion is composed of two parts, front and rear, which are movably connected via a connecting device and can deflect relative to each other within a certain angle range.

The crawler walking mechanism also includes a movable extension crawler respectively arranged on the outside of each of the front crawlers, a pulley at one end of the movable extension crawler is fixedly connected to the pulley at the front end of the front crawler, and the free end of the movable extension crawler can be rotated forward or reversely relative to its fixed end within a range of 360 degrees through a control rod, and a fixed ladder crawler respectively arranged on the outside of each of the rear crawlers, a pulley at one end of the fixed ladder crawler is fixedly connected to the pulley at the rear end of the rear crawler, and the free end of the fixed ladder crawler is offset by a certain angle relative to the rear crawler.

The seat adjustment mechanism and the movable extension crawler belt are respectively driven by separate reduction motors, and each set of crawlers of the crawler walking mechanism is respectively driven by a separate electric engine.

A set of roller wheels is provided at the bottom of each side of the movable seat portion, and the seat portion is supported on the body portion by the roller wheels. Each set of roller wheels is controlled to move along a sliding path formed on the body portion by a control device.

The control device for controlling the roller wheel includes a control rod electrically connected to the reduction motor of the seat adjustment mechanism and a safety lock device arranged on the vehicle body part.

The safety lock device is a double-wing safety lock device, which includes a housing, a pair of spring-loaded locking members fixed to the housing wall, two small gears, one of which is configured as a small motor, and each of the locking members has a small tooth edge and a large tooth edge. The two small gears respectively engage with the small tooth edge of one of the locking members, and the large tooth edges of the two locking members engage with the teeth of the arc-shaped bottom edge of the longitudinal plate of the seat part when the safety lock device is in the locked state. When in the unlocked state, the large tooth edges of the locking members leave the teeth of the arc-shaped bottom edge of the longitudinal plate under the drive of the small gears and are locked in their initial positions by their respective springs.

The reduction motor for driving the seat adjustment mechanism includes an anti-reverse helical gear.

The seat adjustment mechanism includes a balance sensing device, which includes a weight serving as a pendulum and a bracket portion for supporting and allowing the weight to swing. The bracket portion is equipped with a circuit system, which is electrically connected to the reduction motor used for the seat adjustment mechanism and to the battery.

The reduction motor for driving the movable extension track includes an anti-reverse spiral gear and a double-wing safety lock device.

The seat part is connected to the large gear in the reduction motor for driving the seat adjustment mechanism through a connecting piece.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is a perspective view of an embodiment of an electric wheelchair according to the present invention, in which only a portion of the components are schematically shown, wherein the movable extension track is in a storage position alongside the front track.

FIG2 is a schematic partial cross-sectional view of the electric wheelchair shown in FIG1 , wherein the movable extension track is in a position flipped forward to a certain angle.

3a is a top view of some drive components in the body portion and the underbody portion of one embodiment of the electric wheelchair shown in FIG1 , wherein the electric engine is disposed in the rear portion of the underbody portion.

3 b is a top view of some drive components in the body portion and the bottom portion of another embodiment of the electric wheelchair shown in FIG. 1 , wherein the electric engine is disposed in the front portion of the bottom portion.

FIG4 is a schematic diagram of an anti-reverse gear assembly.

FIG5 a is a simplified diagram of the operation design of the seat adjustment mechanism of the electric wheelchair according to the present invention.

5 b is a schematic diagram of the balance sensing device of the seat adjustment mechanism according to the present invention in an initial position, wherein only the longitudinal side panel on the right side of the wheelchair and the longitudinal panel of the seat support member shown in FIG. 2 are shown in the figure.

FIG5c is a schematic diagram illustrating the operation of the balance sensing device shown in FIG5b when it reaches one end position.

FIG5 d is a schematic diagram showing the insulating plate of the balance sensing device shown in FIG5 b in contact with the sensing button of the rod-shaped member of the blocking device at the end position.

6a and 6b are schematic diagrams of two adjustment modes of the seat part.

FIG7 a is a schematic structural diagram of the double-wing safety lock in a locked state.

FIG7 b is a schematic structural diagram of the double-wing safety lock when it is in an unlocked state.

FIG8 is a diagram showing the position of the movable extended tracks of the electric wheelchair of the present invention when ascending or descending stairs.

FIG9 is a schematic diagram of the electric wheelchair according to the present invention when the seat is in a raised state.

FIG10 is a schematic diagram showing that when the electric wheelchair of the present invention climbs to the top of the stairs, the front and rear parts of the bottom portion of the vehicle are relatively deflected at a certain angle so that the rear part lands first.

DETAILED DESCRIPTION

Figure 1 shows a perspective view of one embodiment of an electric wheelchair according to the present invention. For clarity, only some components are shown schematically. The electric wheelchair according to the present invention comprises a seat portion 1, a body portion 2 serving as a seat frame, a seat adjustment mechanism 3, a floor portion 4, and a track mechanism 5.

The seat portion 1 comprises a seat and support assemblies 100 fixedly arranged on opposite sides of the seat bottom. Since the two support assemblies are identical in structure, only one of the support assemblies will be described herein.

Each support assembly 100 includes two longitudinal plates 101, 102 (or 108, 109) that are substantially perpendicular to the seat bottom. The top edges of the two longitudinal plates are fixed to the seat bottom at a certain distance from each other. The bottom edge of the outer longitudinal plate 102 is formed into an inwardly concave toothed arc edge 105 (the bottom edge of the other outer longitudinal plate 109 is not shown in the figure). A space 103 is defined between the two longitudinal plates 101, 102 for accommodating and mounting a plurality of roller wheels 104. The ends of the shaft of each roller wheel are respectively fixed to the two longitudinal plates.

The body portion 2, serving as the seat support, comprises a bottom frame (or floor) and two identical longitudinal side panels 201, 203. The upper portion of each longitudinal side panel 201, 203 is arcuate. In this embodiment, the arcuate top portion is partially clamped within the space 103 defined by the two longitudinal panels 101, 102, 108, 109 of the seat support. A series of roller wheels 104, mounted between the two longitudinal panels 101, 102, 108, 109 of each support, are slidably supported on the arcuate top edges of the longitudinal side panels 201, 203, with the arcuate top edges serving as sliding paths for the roller wheels 104. A safety lock device 11 (only one shown) is provided on the outer sidewall of each longitudinal side panel 201, 203. This safety lock device 11 cooperates with the toothed arcuate edge of the outer longitudinal panel of the seat support, as will be described in detail below.

A reduction motor 6 for operating the movable extension track and a reduction motor 7 for operating the seat adjustment mechanism 3 are provided on the bottom frame of the vehicle body 2, as shown in FIG2 .

The gear train of the reduction motor 7 of the seat adjustment mechanism 3 includes a large gear 73. On the one hand, the large gear 73 is fixedly connected to the seat portion 1 via a connecting member 107 (see Figure 1). On the other hand, it is movably connected to the two longitudinal side panels 201, 203 of the body portion 2 via a rod 14 passing through its center hole. The two ends of the rod 14 are respectively fixed to the center position of the arc-shaped portion of the longitudinal side panels 201, 203, and the large gear 73 can rotate around the rod 14.

The components for driving the crawler tracks are preferably arranged in the vehicle floor part 4 located below the vehicle body part 2 .

The crawler track mechanism 5 comprises two sets of tracks, one located below each side of the vehicle floor 4. Each set of tracks includes a front track 51, a rear track 52, a movable extension track 53 disposed outside the front track 51, and a fixed climbing track 54 disposed outside the rear track 52. The front and rear tracks 51, 52 are connected together via a connecting device 45 (e.g., another track). A pulley 506 at one end of the fixed climbing track 54 is fixedly connected side by side to the drive pulley at the rear end of the rear track 52. The other end of the fixed climbing track is offset at a certain angle relative to the rear track (see Figure 2). A pulley 503 at one end of the movable extension track 53 is fixedly connected side by side to the pulley at the front end of the front track 51. The free end of the movable extension track 53 can rotate 360 degrees forward or backward around the pulley 503 at its fixed end. The pulleys 503 at the fixed ends of the two movable extension tracks are connected by a shaft 9, wherein the shaft 9 freely passes through the center holes of the two pulleys at the front end of the front track, and the shaft 9 is eccentrically connected to the large gear 64 in the gear set of the reduction motor 6 used to control the movable extension track through a connecting rod 91 at its middle position.

Referring to Figures 2, 3a, 3b, and 10, the underbody 4 consists of two side-by-side sections 41 and 42. The front section 41 and the rear section 42 are connected by a connecting device 45 and can pivot relative to each other within a certain range of angles. In this embodiment, the connecting device 45 is a track, which connects the front and rear sections via a pulley at the rear end of the front track 51 and a pulley at the front end of the rear track 52. Of course, the connecting device 45 is not limited to the aforementioned track; other devices known in the art, such as chains, may also be used.

Referring to Figure 3a, a battery 8 for powering the various drive devices is located in the front portion 41. Two separate electric motors 421 and 422 are located in the rear portion 42 and are each used to drive one set of tracks, enabling forward or backward movement and 360-degree horizontal steering to the left or right. These two electric motors 421 and 422 are controlled by a control lever 170 located on the seat armrest. In this embodiment, the electric motors 421 and 422 directly drive the pulley 506 at the rear end of the rear track 52, which in turn drives the front track 51 via the connecting device 45. Because the pulley 503 at one end of the movable extension track 53 is fixedly connected to the pulley at the front end of the front track 51, the power from the electric motors is also transmitted to the movable extension track, causing it to operate.

In another embodiment, as shown in FIG3b , a battery 8 for powering the various drive devices is located in the rear portion 42. Two separate electric motors 421 and 422 are located in the front portion 41 and are each used to drive one set of tracks, enabling the track set to travel forward or backward and to steer 360 degrees left or right. These two electric motors 421 and 422 are controlled by a control lever 170 located on the seat armrest. In this embodiment, the electric motors 421 and 422 directly drive the connecting device 45 and the pulley 504 at the rear end of the front track 51. The electric motors 421 and 422 then drive the rear track 52 via the connecting device 45, which in turn drives the fixed climbing track 54 via the pulley 506 at the rear end of the rear track 52.

The reduction motor 6, used to operate the movable extendable track, drives the movable extendable track 53 via a shaft 9, allowing the free end of the movable extendable track 53 to rotate to any angle relative to its fixed end and then stop. This is achieved by an anti-reverse helical gear 62 in the gear train of the reduction motor 6. Referring to Figure 4, the anti-reverse helical gear 62 is directly driven by the motor 60 of the reduction motor 6 via a shaft 61 and meshes with a gear 68 in the gear train of the reduction motor 6. When the motor is powered on, the anti-reverse helical gear 62 drives the gear 68 to rotate, in turn rotating the movable extendable track 53. However, when the motor is powered off and stopped, the anti-reverse helical gear 62 also stops rotating because the gear 68 cannot push the anti-reverse helical gear 62, locking the movable extendable track 53 in the desired position. The reduction motor 6 is controlled by a control lever 160 located on the seat armrest.

Similarly, the gear train of the reduction motor 7 used to operate the seat adjustment mechanism 3 also includes an anti-reverse helical gear 72, as shown in Figure 2. When the reduction motor 7 is powered on, the helical gear 72 drives the gear train to rotate. A large gear 73, fixedly connected to the seat, drives the seat portion 1 forward or backward along the sliding path along the upper edges of the longitudinal side panels 201, 203 of the body portion 2. When the motor stops, the gear train cannot push the helical gear, locking the seat in place.

Referring to FIG5a , the seat adjustment mechanism 3 includes a balance sensing device 300 disposed on the seat bottom. In one embodiment, the balance sensing device 300 includes a weight 302 and a support member 304 configured with an electrical circuit system for supporting the weight 302. The balance sensing device 300 can be fixed to the seat bottom in a hanging manner using conventional methods. In one embodiment, the balance sensing device 300 is fixed between the two inner longitudinal plates 101, 108 of the seat bottom and adjacent to one of the inner longitudinal plates 101 or 108.

Weight 302 is movably connected to support member 304 via two connecting rods 306 and 308 on opposite sides of the weight. The connection point 310 between each connecting rod 306 and 308 and support member 304 serves as a fulcrum, allowing weight 302 to swing forward (in the direction indicated by arrow A in the figure, i.e., the direction the passenger is facing) or backward around the fulcrum as a pendulum. In this embodiment, the two connecting rods 306 and 308 are generally T-shaped. Two opposing positive contacts c and e are provided on the free end of one connecting rod 306, and two opposing negative contacts d and f are provided on the free end of the other connecting rod 308. Contacts a and g, corresponding to the positive contacts c and e of connecting rod 306, are located on the side edge of support member 304 on the same side as connecting rod 306. Contacts b and h, corresponding to the negative contacts d and f of connecting rod 308, are located on the side edge of support member 304 on the same side as connecting rod 308. Contacts a and h on support member 304 are connected via a wire L, while contacts b and g are connected via a wire K. Contacts g and h are electrically connected to the reduction motor 7 for controlling the seat adjustment mechanism via wires I and J, respectively. Connecting rods 306 and 308 are electrically connected to an automatic/manual mode switch 155 via wires M and N, respectively. This automatic/manual mode switch 155 can be located on the armrest or elsewhere convenient for passengers. It is electrically connected to the battery 8 installed in the vehicle floor and to the control lever 150 on the armrest for controlling the reduction motor 7 for controlling the seat adjustment mechanism. The operation mode of the seat adjustment mechanism 3 is switched by the automatic/manual mode switching switch 155 .

When automatic mode is activated, the balance sensor 300 located at the bottom of the seat is powered. When ascending or descending stairs, the passenger or wheelchair must face away from the stairs. If the wheelchair tilts during travel (i.e., the rear portion rises), the weight 302 of the balance sensor 300 swings forward, causing the positive contact e of the connecting rod 306 to contact contact g of the bracket 304. Simultaneously, the negative contact f of the connecting rod 308 contacts contact h of the bracket 304, thereby energizing the power supply. Current flows through contact g and contact h, activating the seat adjustment mechanism's reduction motor 7, causing the seat to rotate from point Y toward point Z, maintaining constant balance with the ground. Conversely, when the electric wheelchair moves forward up an incline, weight 302 swings backward, causing the positive contact c of connecting rod 306 to contact contact a of bracket 304 and then connect to contact h of bracket 304 via wire L. Simultaneously, the negative contact d of connecting rod 308 contacts contact b of bracket 304 and then connects to contact g of bracket 304 via wire K. Finally, current flows through contacts g and h, with their positive and negative poles swapped, activating reduction motor 7 in reverse, causing the seat to rotate from point Y toward point X, maintaining balance with the ground. When the electric wheelchair ascends or descends an incline, the passenger or the wheelchair can choose to face or face the incline, depending on the specific situation. If facing the incline, the situation is similar to the above description; if facing the incline, the situation is reversed.

Referring to Figures 5b to 5d, to ensure safe and reliable movement of the seat portion, in one embodiment, an insulating plate 311 (see Figure 5c) can be positioned between the two connecting rods 306 and 308 located on the support member 304. The ends of the insulating plate can be fixed to the two connecting rods 306 and 308, respectively. Furthermore, two generally L-shaped inductive blocking devices 312 and 313 are positioned on the inner wall of one of the longitudinal side panels 201 of the vehicle body 2. These blocking devices are located along the motion path of the balance sensing device 300 and serve to limit the range of movement of the seat portion. Because the motion path of the balance sensing device 300 lies on an arc centered at the fixed end point of the rod 14, in this embodiment, the forward or backward movement of the seat portion is limited to, for example, a 40-degree range.

To this end, the two blocking devices 312 and 313 are respectively disposed at the two ends of the motion path of the balance sensing device 300, so that each of them forms a 40-degree angle with the balance sensing device 300 in the radial direction. It should be noted that those skilled in the art will appreciate that this angle can be set to a smaller or larger value to accommodate steps with different inclination angles, as the inclination angle of most stairs is between 20 and 35 degrees.

The lower portion of each blocking device is fixed to the inner wall of the longitudinal side panels 201, 203, while the upper portion is spaced a certain distance from the inner wall of the longitudinal side panels 201, 203 to allow the inner longitudinal panels 101, 108 of the seat support assembly 100 to pass freely between the blocking device and the inner wall of the longitudinal side panels 201, 203. Each of the two blocking devices 312, 313 is also provided with a rod-shaped member 314, 315 on the facing side. The rod-shaped member extends generally perpendicularly from the upper portion of the blocking device body. A sensor button 316, which serves as an alarm switch, is provided on the end facing away from the body. The sensor button 316 is configured to elastically retract into the rod-shaped member when pressed and is electrically connected to an alarm (not shown) installed on the wheelchair. The alarm can be located at any suitable location on the wheelchair body. When the sensing button 316 of the rod-shaped members 314 and 315 is in the released state, the total axial length of the rod-shaped members 314 and 315 is greater than the distance between the main body of the rod-shaped member and the insulating plate 311 of the balance sensing device 300 when the rod-shaped member is in contact with the balance sensing device 300. This allows the sensing button 316 to contact the insulating plate 311 and be pressed into the interior of the rod-shaped member to activate the alarm.

When the wheelchair ascends or descends a steep slope, for example, facing upward facing the slope, in this embodiment, the balance sensing device 300 is positioned between the inner longitudinal plate 108 of the support member 100 and the seat bottom on the right side of the seat portion (i.e., the passenger's right-hand side) (see Figure 5b). When the wheelchair tilts due to ascending the slope (i.e., the front portion of the wheelchair rises), the weight 302 swings backward due to gravity, causing the contacts a, b of the balance sensing device 300 to contact c, d, activating the reverse rotation of the reduction motor 7, thereby moving the seat from point Y to point X (see Figure 5a). When the wheelchair tilts to 40 degrees, the balance sensing device 300 moves forward with the seat until it contacts the blocking device 313, as shown in Figures 5c and 5d. At this point, the sensing button 316 of the rod 315 of the balance sensing device 300 is compressed by the insulating plate 311 into the rod 315, activating an alarm. This sounds, alerting the passenger that the wheelchair has reached its limit of tilt and that further movement is prohibited. On the other hand, because the rod-shaped member 315 of the blocking device 313 abuts the insulating plate 311 of the balance sensing device 300, the weight connecting rods 306 and 308 of the balance sensing device 300 remain in their initial position, i.e., their position perpendicular to and undeflected relative to the support member 304. Since the contacts cannot contact the corresponding contacts on the support member 304, the seat cannot slide forward or backward. In this situation, when the wheelchair is returned to a flat surface, the seat remains balanced through the adjustment of the balance sensing device 300 until it safely returns to the flat surface. When manual mode is activated, the current to the balance sensing device 300 is disconnected via a switch, and control is instead performed by the control lever 150 of the reduction motor 7. In this mode, the passenger can freely rotate the seat from point Y to point Z or from point Y to point X using the control lever 150, thereby increasing flexibility and making it easier for passengers to get on and off the wheelchair. For example, as shown in Figures 6a and 6b, by adjusting the seat to the rear, the passenger can wash their hair more conveniently or transfer from the rear to a seat or bed, etc. When the passenger adjusts the seat to the front, the passenger can transfer to the vehicle, seat, or bed, etc. by themselves without the help of others.

The seat adjustment mechanism 3 also includes a safety lock device 11 disposed on the outer side wall of each longitudinal side panel 201, 203 of the body portion 2 and capable of engaging with the teeth 105 on the arcuate bottom edge of the outer longitudinal panels 102, 109 of the seat portion. This safety lock device 11 can be a double-wing safety lock device (see Figures 7a and 7b). It includes a housing 110, a pair of locking members 111, 112 fixed to the housing wall and activated by springs 115, 116, and two pinions 113, 114, one of which is configured as a small motor. Each locking member has a small tooth edge and a large tooth edge. The two pinions 113, 114 respectively engage with the small tooth edge of one locking member, while the large tooth edges of the two locking members engage with the teeth 105 on the arcuate bottom edge of the outer longitudinal panels 102, 109 when the safety lock device is in the locked state. When unlocked, the large teeth of the locking element, driven by the pinion, clear the teeth 105 on the arcuate bottom edges of the longitudinal plates 102, 109 and locked in their initial positions by respective springs 115, 116. When this safety lock is in use, the power supply for the small motor 114 is directly connected to the motor of the reduction motor 7 of the seat adjustment mechanism 3. When the wheelchair is moving steadily, the swing of the weight 302 of the balance sensor 300 is insufficient to power the balance sensor. Neither the motor of the reduction motor 7 nor the small motor 114 of the safety lock is powered on. Consequently, the left and right locking elements of the safety lock lock the wheelchair due to the spring force. When the wheelchair is tilted, the balance sensing device simultaneously activates the motor of the reduction motor 7 and the small motor 114 of the safety lock. The small motor rotates clockwise, causing the locking element engaged therewith to rotate counterclockwise and disengage from the teeth 105 on the arc-shaped bottom edge of the longitudinal plates 102, 109. At the same time, the small motor drives another small gear to rotate counterclockwise, causing the other locking element to also disengage from the teeth 105 on the arc-shaped bottom edge of the longitudinal plates 102, 109, thereby allowing the movable seat portion to slide smoothly.

Because there are two locking members, no matter which direction the wheelchair is tilted, such as in the manual mode shown in Figures 6a and 6b, the locking members can lock the wheelchair tightly and prevent it from tipping over.

The above-mentioned double-wing safety lock device is only a preferred embodiment of the present invention. For those skilled in the art, other devices that can achieve this locking function can be used.

To control the movable extendable track, it is preferable to install a double-wing safety lock device 12 in the gear train of the reduction motor 6 that operates the movable extendable track, as shown in Figure 2. Thus, when the reduction motor 6 is powered, the safety lock device 12 automatically unlocks, allowing the gear train of the reduction motor 6 to drive the movable extendable track 53 to rotate to the desired position. When the motor stops, the safety lock locks the gear train, preventing the movable extendable track 53 from rotating and causing it to remain in the desired position.

Because the electric wheelchair of the present invention employs an anti-reverse spiral gear and a double-wing safety lock device, the movable seat and movable extension tracks of the wheelchair can maintain stability under any circumstances, thereby achieving the purpose of passenger safety.

Furthermore, because the electric wheelchair of the present invention utilizes 360-degree rotatable extendable tracks, the extendable tracks can be rotated forward when necessary until the front ends of the extendable tracks touch the ground, thereby raising the wheelchair. Simultaneously, the seat adjustment mechanism of the present invention automatically adjusts the movable seat to a vertically balanced position, allowing the passenger to enjoy the same visual field as a healthy person standing upright. When the electric wheelchair encounters an obstacle while moving forward, the extendable tracks can be rotated backward until the front ends of the extendable tracks touch the ground, raising the front end of the wheelchair body enough to clear the obstacle and allow the wheelchair to pass smoothly.

When using the electric wheelchair of the present invention to ascend multiple steps, the passenger first turns the wheelchair with its back to the steps. Using one hand, control the track travel control lever 170 to slowly propel the wheelchair backward. Once the fixed ascending track touches the step, the rear track is used to ascend the step. Simultaneously, using the other hand, control the movable extension track control lever 160 to flip the extension track forward from both sides so that it is aligned with the front and rear tracks. Because the wheelchair tilts when ascending an inclined staircase, the seat adjustment mechanism comes into play to help the passenger maintain vertical balance. When the wheelchair reaches the top of the step, the rear portion of the wheelchair lands first, while the front track remains on the step. At this point, the rear track is deflected at a certain angle relative to the front track, as shown in Figure 10. This allows the rear track to land smoothly, avoiding the impact of a sudden drop. Once the wheelchair reaches level ground, the front and rear tracks return to a straight line. Using the control lever 160, the extension track can be flipped backward and laid flat on either side of the wheelchair to reduce its length.

When descending multiple steps, the passenger carefully maneuvers the wheelchair to the edge of the step. Using the movable extension track control levers 160, the extension tracks tilt forward from both sides until the front ends contact the step. The passenger then slowly propels the wheelchair forward, using the extension tracks to maintain stability. As the wheelchair tilts as it descends, the seat adjustment mechanism helps the passenger maintain vertical balance. When the wheelchair reaches the ground, the front ends of the extension tracks touch the ground first. The passenger then slowly retracts the extension tracks to ensure a smooth landing.

When a passenger gets on the wheelchair, the power supply of the balance sensor is first turned off to switch the seat adjustment mode from automatic to manual mode. The control lever 150 is used to control the seat tilt angle. When the angle is appropriate, the anti-reverse gear combination and the safety lock will lock the seat at the angle position required by the passenger, allowing the passenger to safely transfer from a bed, a seat, a toilet, etc. to the wheelchair, and vice versa.

The various control levers and switch devices mentioned above can be arranged on one side or both sides of the wheelchair armrests, or other places that are convenient for passengers to reach.

Although the advantages and preferred embodiments of the present invention have been described herein, those skilled in the art will appreciate that these descriptions are provided for illustrative purposes only and are not intended to limit the scope of the present invention. The described implementation details may be replaced with any other equivalents, or modifications or variations may be made without departing from the scope of the present invention.

Claims (12)

1. A walking device for the underside of an electric wheelchair body, comprising a chassis portion (4) and a tracked walking mechanism (5), wherein the tracked walking mechanism (5) comprises two sets of tracks respectively disposed on both sides below the chassis portion (4), characterized in that the chassis portion (4) is composed of a front portion (41) and a rear portion (42). The front part (41) and the rear part (42) are connected by a connecting device (45) and can deflect relative to each other within a certain angle range. Each of the two sets of tracks in the tracked walking mechanism (5) includes a front track (51), a rear track (52), and a movable extension track (53) disposed outside the front track (51). The movable extension track (53) can rotate forward until its free end touches the ground, thereby raising the front part (41). The movable extension track (53) can also rotate backward until its free end touches the ground, thereby raising the front part (41) to cross obstacles. Wherein, the pulley (503) at one end of the movable extended track (53) is fixedly connected to the pulley at the front end of the front track (51), and the free end of the movable extended track (53) can rotate in a 360-degree range around the pulley (503) at one end of the movable extended track (53) in either the forward or reverse direction; and Each of the two sets of tracks in the tracked walking mechanism (5) further includes a fixed upper ladder track (54) disposed outside the rear track (52). A pulley (506) at one end of the fixed upper ladder track (54) is fixedly connected to a pulley at the rear end of the rear track (52), and the other end of the fixed upper ladder track (54) is offset relative to the rear track (52) at a certain angle. 2. The apparatus of claim 1, wherein the connecting device (45) is a track. 3. The apparatus of claim 1, wherein the front track (51) and the rear track (52) are connected by the connecting device (45). 4. The device as claimed in claim 1, wherein the pulleys (503) at the fixed ends of the two movable extended tracks (53) are connected by a shaft (9) which freely passes through the center hole of the pulley at the front end of the two front tracks (51). 5. The device as claimed in claim 3, wherein the front portion (41) includes a battery (8) and the rear portion (42) includes two separate electric motors (421, 422) for driving two sets of tracks of the tracked walking mechanism (5), respectively. 6. The apparatus of claim 5, wherein the electric motor (421, 422) directly drives the pulley at the rear end of the rear track (52) and drives the front track (51) to run via the connecting device (45). 7. The apparatus of claim 3, wherein the rear portion (42) includes a battery (8) and the front portion (41) includes two separate electric motors (421, 422) for driving two sets of tracks of the tracked walking mechanism (5), respectively. 8. The apparatus of claim 7, wherein the electric motor (421, 422) directly drives the connecting device (45) and the pulley at the rear end of the front track (51), and drives the rear track (52) to run via the connecting device (45). 9. A method for climbing stairs using the device as described in any one of claims 1-8, comprising the following steps: Position the device so that it faces away from the ladder steps and drive it backward; When the fixed upper track (54) touches the step, the rear track (52) climbs up the step; The movable extension track (53) is flipped forward to be in line with the front track (51) and the rear track (52); When the device reaches the top of the step, the rear part (42) and the rear track (52) land first, while the front track (51) remains on the step; Once the device has reached flat ground, the movable extended track (53) is flipped backward and laid flat on both sides of the underside (4). 10. A method for lowering steps using the device as described in any one of claims 1-8, comprising the following steps: Drive the device to the edge of the ladder. The movable extended track (53) is flipped forward until the free end of the movable extended track (53) contacts the step; To move the device forward; When the free end of the movable extended track (53) touches the ground, the movable extended track (53) is flipped backward so that the device touches the ground. 11. A method for climbing stairs using a wheelchair, the wheelchair comprising a movable seat portion, a vehicle body portion serving as a seat support, a seat adjustment mechanism disposed under the seat for maintaining the balance of the seat portion, a vehicle bottom portion located below the vehicle body portion, and a tracked walking mechanism, the tracked walking mechanism comprising two sets of tracks respectively disposed on both sides below the vehicle bottom portion, each set of tracks comprising a front track and a rear track, characterized in that the vehicle bottom portion is composed of front and rear parts, the front and rear parts being movably connected by a connecting device and capable of relative deflection within a certain angle range; the tracked walking mechanism further comprising movable extended tracks respectively disposed on the outer side of each of the front tracks, a pulley at one end of the movable extended track being fixedly connected to a pulley at the front end of the front track, the free end of the movable extended track being able to rotate relative to its fixed end in a 360-degree range via a control rod, and fixed upper ladder tracks respectively disposed on the outer side of each of the rear tracks, a pulley at one end of the fixed upper ladder track being fixedly connected to a pulley at the rear end of the rear track, Furthermore, the free end of the fixed upper track is offset relative to the rear track by a certain angle. The method includes the following steps: Position the wheelchair so that its back faces the steps, and control the lever to drive the wheelchair backward; When the fixed upper track touches the step, the rear track climbs up the step; Controlling the control lever causes the movable extended track to flip forward from both sides to align with the front and rear tracks. At this time, the seat adjustment mechanism is activated to keep the passenger vertically balanced. When the wheelchair reaches the top of the step, the rear part and the rear track land first, while the front track is still on the step. At this time, the rear track deflects at a certain angle relative to the front track. Once the wheelchair has reached level ground, the front and rear tracks are aligned, and the control lever is used to flip the movable extension tracks backward and lay them flat on both sides of the vehicle's underside. 12. A method for descending a wheelchair using a ladder, the wheelchair comprising a movable seat portion, a vehicle body portion serving as a seat support, a seat adjustment mechanism disposed under the seat for maintaining the balance of the seat portion, a vehicle bottom portion located below the vehicle body portion, and a tracked traveling mechanism, the tracked traveling mechanism comprising two sets of tracks respectively disposed on both sides below the vehicle bottom portion, each set of tracks comprising a front track and a rear track, characterized in that the vehicle bottom portion is composed of front and rear parts, the front and rear parts being movably connected by a connecting device and capable of relative deflection within a certain angle range; the tracked traveling mechanism further comprising movable extended tracks respectively disposed on the outer side of each of the front tracks, a pulley at one end of the movable extended track being fixedly connected to a pulley at the front end of the front track, the free end of the movable extended track being able to rotate in a 360-degree range relative to its fixed end via a control rod, and fixed upper ladder tracks respectively disposed on the outer side of each of the rear tracks, a pulley at one end of the fixed upper ladder track being fixedly connected to a pulley at the rear end of the rear track, Furthermore, the free end of the fixed upper track is offset relative to the rear track by a certain angle. The method includes the following steps: Move the wheelchair to the edge of the step; The control lever is used to manipulate the movable extension track to flip forward from both sides until the free end of the movable extension track contacts the step; The wheelchair is moved forward, and the movable extended tracks control the vehicle body to remain stable. When the vehicle body tilts as it descends the stairs, the seat adjustment mechanism keeps the passenger vertically balanced. When the free end of the movable extension track touches the ground, the movable extension track retracts backward to allow the wheelchair to touch the ground.