FR3032348A1 - SUSPENSION STRUCTURE FOR AN ELECTRIC WHEELCHAIR - Google Patents

Abstract

The invention relates to a simple suspension structure for an electric wheelchair, which structure comprises a frame (10), two drive units (20), two front guide units (40), two front dampers (50), two anti-overturning units (60) and two rear shocks (70). When the front suspension arms (42) cause the front guide wheels (41) to pivot, the torsion springs (43) can produce a reaction force to prevent the frame (10) from turning over, improving safety. When the suspension structure passes on an uneven bumpy road, the front (50) and rear (70) dampers can mitigate shocks imposed on the frame (10), improving the sitting comfort.

Description

This invention relates to a suspension structure and, more particularly, to a suspension structure for an electric wheelchair. BACKGROUND OF THE INVENTION A conventional electric wheelchair disclosed in Taiwanese Patent Application No. 098214606 generally includes a frame connected to a small front wheel, a large front wheel, and a rear small wheel. A connecting element, a shock absorber and a front arm are connected between the frame and the small front wheel. The connecting element is pivotally connected to the frame, the front arm is pivotally connected to the connecting element, the damper is mounted between the connecting element and the front arm, and the large front wheel is connected to a motor and to the front arm. A rear arm is connected to the small rear wheel and is pivotally connected to the chassis, and a damper is also mounted between the chassis and the rear arm. Shock absorbers can reduce shocks and improve sitting comfort when small front and rear wheels drive on bumpy roads. However, this conventional suspension structure of the electric wheelchair is very complicated and difficult to assemble, and a complicated structure further reduces the structural strength of the suspension structure. In addition, the conventional suspension structure provides only a damping effect, but is not able to prevent a reversal. Another conventional suspension structure for an electric wheelchair described in U.S. Patent No. 8408598 has a structure that has been simplified, but is still not able to prevent a rollover. The present invention aims to mitigate and / or eliminate the disadvantages described above.

The main object of the present invention is to provide a suspension structure which is simple for an electric wheelchair, which is easy to assemble and capable of improving the sitting comfort and safety of the wheelchair.

To this end, the present invention relates to an electric wheelchair suspension structure, comprising: a frame having an upper side, a lower side, a front end and a rear end, a seat being mounted on the upper side, a direction extending from the front end to the rear end being defined as a first direction and a direction perpendicular to the first direction being defined as a second direction; two drive units located on both sides of the chassis and each comprising a bogie and a transmission device attached to the bogie, one end of each of the bogies being pivotally connected to the chassis via a pivot unit each of the transmission devices extending towards the other end of each of the bogies, the suspension structure being characterized in that: - each of the bogies further comprises an assembly section extending according to the second direction; two driving wheels are connected to the transmission devices and driven in rotation by them; two front guide units are located on both sides of the frame and each comprise a front guide wheel, a front suspension arm and a torsion spring, the front guide wheels being pivotally connected to one end respectively. front suspension arms, and the other end of each of the front suspension arms being pivotally connected to the chassis via a front suspension arm pivot pin and located near the front end, each of the torsion springs being fitted on the front suspension arm pivot axis and having one end secured to the second front extension section and the other end bearing against the lower side, near the front end chassis; two front dampers each have one end pivotally connected between the two ends of each of the front suspension arms and the other end pivotally connected to the assembly section of each of the bogies, and extend in one direction which forms a front shock angle with respect to the first direction; two anti-overturning units are located on both sides of the chassis and each comprise a rollover wheel and a rear suspension arm, each of the anti-rollover wheels being pivotally connected to one end of each of the rear suspension arms, and the other end of each of the rear suspension arms is pivotally connected to the chassis via a rear suspension arm pivot pin; and - two rear shocks each have one end pivotally connected between two ends of each of the rear suspension arms and the other end pivotally connected to the chassis, and extend in a direction which forms an angle of rotation. rear damper with respect to the first direction, the rear damper angle being defined between an edge of each of the rear dampers near the front dampers and the first direction, the front damper angle being defined by an edge of each front dampers near the rear dampers with respect to the first direction, and the front damping angle being larger than the rear damping angle.

According to particular optional features, a first front extension section and a second front extension section are formed between the two ends of each of the front suspension arms, the first front extension section extending according to the first direction and the second forward extension section extending to the lower side and defining an angle with respect to the first direction, each of the torsion springs having one end secured to the second forward extension section and the other end thereof support against the lower side, near the front end of the chassis. According to optional special features, a first rear extension section and a second rear extension section are formed between two ends of each of the rear suspension arms, the first rear extension section extending in the first direction, and the second rear extension section extending to the underside of the frame and forming an angle with respect to the first direction. The present invention will become more apparent upon reading the following description, taken in conjunction with the accompanying drawings which show, for purposes of illustration only, the preferred embodiment of the present invention.

In these drawings: - Figure 1 shows an electric wheelchair suspension structure according to a preferred embodiment of the present invention, assembled on the electric wheelchair; Figure 2 is a perspective view of the electric wheelchair suspension structure according to the present invention; Figure 3 is a top view of the electric wheelchair suspension structure according to the present invention; Figure 4 is a sectional view of the electric wheelchair suspension structure according to the present invention; Figure 5 shows the transmission unit, the front guide unit and the front shock absorber of the electric wheelchair suspension structure according to the present invention; Figure 6 shows the electric wheelchair suspension structure according to the present invention, placed on a flat support surface; Figure 7 shows the suspension structure for an electric wheelchair according to the present invention, which rides a convex obstacle; and Figure 8 shows the suspension structure for the electric wheelchair according to the present invention, which passes over a concave obstacle.

Referring to Figures 1-8, it can be seen that an electric wheelchair suspension structure according to a preferred embodiment of the present invention comprises: a chassis 10, two drive units 20, two driving wheels 30, two front guiding units 40, two front shocks 50, two reversing units 60 and two rear shocks 70. The frame 10 comprises an upper side 11, a lower side 12, a front end 13 and an end. 14. A seat A is mounted on the upper side 11.

The direction extending from the front end 13 to the rear end 14 is defined as the first direction D1 and the direction which is perpendicular to the first direction D1 is defined as the second direction D2. The two drive units 20 are located on both sides of the frame 10 and each comprise a bogie 21 and a transmission device 22 fixed to the bogie 21. One end of each of the bogies 21 is pivotally connected to the chassis 10 by Via a transmission pivot unit 211, and each of the transmission devices 22 extends to the other end of each of the bogies 21. Each of the bogies 21 further comprises an assembly section 212 extending in the second direction D2. The two driving wheels 30 are connected to the transmission devices 22 and driven in rotation by them. The two forward guide units 40 are located on both sides of the frame 10 and each comprise a front guide wheel 41, a front suspension arm 42 and a torsion spring 43. The front guide wheels 41 are respectively connected to each other. pivotably at one end of the front suspension arms 42, and another end of each of the front suspension arms 42 is pivotally connected to the chassis 10 via a front suspension arm pivot pin 421 and is located near the front end 13. A first front extension section 422 and a second front extension section 423 are formed between the two ends of each of the front suspension arms 42. In this embodiment, the first front extension section 422 is a straight flat section extending in the first direction D1, and the second forward extension section 423 is an oblique section extending to the side bottom 12 and forms an angle with respect to the first direction Dl. Each of the torsion springs 43 is fitted on the front suspension arm pivot axis 421 and has one end attached to the second front extension section 423 and the other end bearing against the lower side 12 near the front suspension arm 421. front end 13 of chassis 10. Each of the two front dampers 50 has one end pivotally connected between the two ends of each of the front suspension arms 42 and the other end pivotally connected to the assembly section 212 each of the bogies 21, and extends in a direction which forms a buffer angle before 01 relative to the first direction Dl. The two anti-rollover units 60 are located on both sides of the frame 10 and each comprise an anti-rollover wheel 61 and a rear suspension arm 62. The anti-rollover wheel 61 is pivotally connected to one end of the arm rear suspension arm 62, 3032348 8 and the other end of the rear suspension arm 62 is pivotally connected to the chassis 10 via a rear suspension arm pivot pin 621. A first rear extension section 622 and a second rear extension section 623 are formed between the two ends of each of the rear suspension arms 62. The first rear extension section 622 is a straight and flat section extending in the first direction D1, and the second rear extension section 623 is an oblique section which extends towards the underside of the frame and forms an angle with respect to the first direction D1. The two rear dampers 70 each comprise one end pivotally connected between two ends of each of the rear suspension arms 62, and the other end is pivotally connected to the frame 10, and extend in a direction which forms a Rear damper angle 02 with respect to the first direction D1. The rear damper angle 02 is defined between the edge of each of the rear dampers 70 near the front dampers 50 and the first direction D1. The front damper angle 01 is defined by the edge of each of the front dampers 50 near the rear dampers 70 with respect to the first direction D1, and 25 01> 02. In other words, the damper angle rear 02 is the angle formed between the first direction D1 and the longitudinal direction of the rear shock absorber 70, which longitudinal direction is the direction passing through the two ends of the rear shock absorber 70. Similarly, in others In other words, the front damper angle 01 is the angle formed between the first direction D1 and the longitudinal direction of the front damper 50.

Referring now to Figures 6 to 8, it can be seen that when the suspension structure of the electric wheelchair according to the present invention is placed on a horizontal support surface G, the driving wheels 30, the front guide wheels 41 and the anti-rollover wheels 61 are all resting against the ground. As the suspension structure passes over a convex obstacle, as shown in FIG. 7, the driving wheels 30 will move the wheelchair forward until the front guide wheels 41 come into contact with the obstacle. At this time, the driving force from the drive units 20 causes the front guide wheels 41 to force the front suspension arms 42 to pivot upward about the front suspension arm pivot axis 421. so that the front guide wheels 41 can easily climb over the obstacle. Meanwhile, the pivoting movement of the front suspension arms 42 compresses the torsion springs 43, so that once the front guide wheels 41 are mounted on the obstacle, the torsion springs 43 will support the wheels. guide 41 before the obstacle through the front suspension arms 42, so as to improve the adhesion of the front guide wheels 41.

The upward rotation movement of the front suspension arm pivot pins 421 also compresses the front dampers 50, and the front dampers 50 push the bogies 21 to pivot toward the lower side 12 of the chassis 10 by movement around the damping units. transmission pivot 211, so that the front dampers 50 absorb the upward pushing force from the forward guide units 40, so as to prevent the frame 10 from turning backwards. After the forward guidance units 40 are passed over the obstacle, the transmission devices 22 continue to drive the front drive wheels 30 forwardly, while the anti-roll units 60 press and release 5 the rear shock absorbers 70, causing the rear suspension arms 62 to pivot about the rear suspension arm pivot axes 621 to change the position of the anti-rollover wheels 61, so that the anti-rollback wheels 61 can pass over the obstacle with success.

When the suspension structure passes over a concave obstacle, as shown in FIG. 8, the driving wheels 30 will move the wheelchair forward until the front guide wheels 41 come into contact with the concave obstacle. . At this time, the front guide wheels 41 lower on the surface of the obstacle which is at different heights relative to the anti-rollover wheels 61, the front dampers 50 will extend to maintain the chassis 10 and the wheels backstop 61 at their original height, so as to stabilize the wheelchair. Once lowered onto the surface of the obstacle, the front guide wheels 41 will cause the front suspension arms 42 to pivot downwardly about the front suspension arm pivot pins 421, causing the 25 second front extension sections 423 of the front suspension arms 42 to compress the torsion springs 43, the torsion springs 43 then push the chassis 10, causing the chassis 10 to produce a reaction force towards the front suspension arms 42, ensuring that the chassis 10 and the anti-overturning units 60 are all actually bearing against the support surface G and preventing the frame 10 from turning forward. The reaction force of the front guide units 40 and the anti-tip units 60 improves the grip performance while substantially reducing the possibility of the wheelchair turning over. After the forward guide units 40 have successfully passed the concave obstacle, the transmission devices 22 continue to drive the driving wheels 30 forward, while the anti-roll units 60 compress and release the wheels. rear shock absorbers 70, causing the rear suspension arms 62 to pivot about the rear suspension arm pivot axes 621 to change the position of the anti-rollover wheels 61, so that the anti-rollover wheels 61 can pass through. obstacle successfully. In general, when the front suspension arms 42 cause the front guide wheels 41 to pivot, the torsion springs 43 can produce a reaction force to prevent the chassis 10 from turning over, thereby improving safety. When the suspension structure passes over an uneven bumpy road, the front and rear dampers 50, 70 can mitigate the shocks imposed on the frame 10, which improves the seating comfort. Although a preferred embodiment of the present invention has been described, it will be apparent to those skilled in the art that modifications can be made without departing from the scope of the present invention.

Claims (3)

CLAIMS1 - An electric wheelchair suspension structure, comprising: a frame (10) having an upper side (11), a lower side (12), a front end (13) and a rear end (14), a seat (A ) being mounted on the upper side (11), a direction extending from the front end (13) to the rear end (14) being defined as a first direction (D1) and a direction perpendicular to the first direction (D1 ) being defined as second direction (D2); two drive units (20) located on both sides of the frame (10) and each comprising a bogie (21) and a transmission device (22) fixed to the bogie (21), one end of each of the bogies (21) being pivotally connected to the frame (10) via a transmission pivot unit (211) and each of the transmission devices (22) extending towards the other end of each of the bogies (21), the suspension structure being characterized in that: - each of the bogies (21) further comprises an assembly section (212) extending in the second direction (D2); - two driving wheels (30) are connected to the transmission devices (22) and driven in rotation by them; two front guide units (40) are located on both sides of the frame (10) and each comprise a front guide wheel (41), a front suspension arm (42) and a torsion spring (43), the front guide wheels (41) being respectively pivotally connected to one end of the front suspension arms (42), and the other end of each of the front suspension arms (42) being pivotally connected to the chassis ( 10) through a front suspension arm pivot axis (421) and located near the forward end (13), each of the torsion springs (43) being engaged on the pivot axis of front suspension arm (421) and having one end attached to the second front extension section (423) and the other end bearing against the lower side (12), near the front end (13) of the chassis ( 10); Two front dampers (50) each have one end pivotally connected between the two ends of each of the front suspension arms (42) and the other end pivotally connected to the assembly section (212) of each of the bogies (21), and 15 extend in a direction which forms a front damper angle (01) with respect to the first direction (D1); two anti-overturning units (60) are located on both sides of the frame (10) and each comprise an anti-rollover wheel (61) and a rear suspension arm (62), each of the anti-rollover wheels (61) being pivotally connected to one end of each of the rear suspension arms (62), and the other end of each of the rear suspension arms (62) is pivotally connected to the chassis (10) via a rear suspension arm pivot pin (621); and two rear dampers (70) each have one end pivotally connected between two ends of each of the rear suspension arms (62) and the other end pivotally connected to the chassis (10), and extend into a direction which forms a rear damper angle (02) with respect to the first direction (D1), the rear damper angle (02) being defined between an edge of each of the rear shock absorbers (70) near the dampers before (50) and the first direction (D1), the front damper angle (01) being defined by an edge of each of the front dampers (50) near the rear dampers (70) relative to the first direction ( D1), and the front damper angle (01) being larger than the rear damper angle (02). 10 2 - electric wheelchair suspension structure according to claim 1, characterized in that a first front extension section (422) and a second front extension section (423) are formed between the two ends of each of front suspension arm (42), the first front extension section (422) extending in the first direction (D1) and the second front extension section (423) extending towards the lower side (12) and defining an angle with respect to the first direction (D1), each of the torsion springs (43) having one end attached to the second forward extension section (423) and the other end bearing against the lower side ( 12), near the front end (13) of the frame (10). 3 - Electric wheelchair suspension structure according to claim 1, characterized in that a first rear extension section (622) and a second rear extension section (623) are formed between two ends of each of rear suspension arm (62), the first rear extension section (622) extending in the first direction (D1), and the second rear extension section (623) extending towards the lower side (12). ) of the frame (10) and forming an angle with respect to the first direction (D1).