EP1767178A1 - Wheelchair suspension - Google Patents
Wheelchair suspension Download PDFInfo
- Publication number
- EP1767178A1 EP1767178A1 EP05020625A EP05020625A EP1767178A1 EP 1767178 A1 EP1767178 A1 EP 1767178A1 EP 05020625 A EP05020625 A EP 05020625A EP 05020625 A EP05020625 A EP 05020625A EP 1767178 A1 EP1767178 A1 EP 1767178A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- frame
- caster
- mainframe
- drive wheel
- assembly
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
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Classifications
-
- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61G—TRANSPORT, PERSONAL CONVEYANCES, OR ACCOMMODATION SPECIALLY ADAPTED FOR PATIENTS OR DISABLED PERSONS; OPERATING TABLES OR CHAIRS; CHAIRS FOR DENTISTRY; FUNERAL DEVICES
- A61G5/00—Chairs or personal conveyances specially adapted for patients or disabled persons, e.g. wheelchairs
- A61G5/04—Chairs or personal conveyances specially adapted for patients or disabled persons, e.g. wheelchairs motor-driven
- A61G5/041—Chairs or personal conveyances specially adapted for patients or disabled persons, e.g. wheelchairs motor-driven having a specific drive-type
- A61G5/043—Mid wheel drive
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61G—TRANSPORT, PERSONAL CONVEYANCES, OR ACCOMMODATION SPECIALLY ADAPTED FOR PATIENTS OR DISABLED PERSONS; OPERATING TABLES OR CHAIRS; CHAIRS FOR DENTISTRY; FUNERAL DEVICES
- A61G5/00—Chairs or personal conveyances specially adapted for patients or disabled persons, e.g. wheelchairs
- A61G5/06—Chairs or personal conveyances specially adapted for patients or disabled persons, e.g. wheelchairs with obstacle mounting facilities, e.g. for climbing stairs, kerbs or steps
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- A—HUMAN NECESSITIES
- A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
- A61G—TRANSPORT, PERSONAL CONVEYANCES, OR ACCOMMODATION SPECIALLY ADAPTED FOR PATIENTS OR DISABLED PERSONS; OPERATING TABLES OR CHAIRS; CHAIRS FOR DENTISTRY; FUNERAL DEVICES
- A61G5/00—Chairs or personal conveyances specially adapted for patients or disabled persons, e.g. wheelchairs
- A61G5/10—Parts, details or accessories
- A61G5/1078—Parts, details or accessories with shock absorbers or other suspension arrangements between wheels and frame
Definitions
- This invention relates to a wheelchair, and more particularly to a wheelchair suspension.
- a conventional suspension disclosed in U.S. Patent Application Publication No. 2004/0060748 A1 is incorporated in a wheelchair 100, and has two side frame assemblies 1, each of which includes a front caster assembly 11, a rear caster assembly 12, a linkage 13, a drive wheel 14, a driving unit 15 and a return spring unit 16.
- the front caster assembly 11 includes a front mainframe 112, a front caster frame 113 extending downwardly from a front end of the front mainframe 112, a drive wheel frame 114 extending downwardly from a rear end of the front mainframe 112, and a front caster 115 disposed pivotally on a lower end of the front caster frame 113.
- the rear caster assembly 12 includes a rear mainframe 122, a front connecting frame 123 extending downwardly from a front end of the rear mainframe 122, a rear caster frame 124 extending downwardly from a rear end of the rear mainframe 122, and a rear caster 125 disposed pivotally on a lower end of the rear caster frame 124.
- the rear mainframe 122 cooperates with the front mainframe 112 to support a seat 300.
- the linkage 13 has two ends connected respectively and pivotally to the front caster frame 113 and the front connecting frame 123.
- the drive wheel 14 has a diameter greater than those of the front and rear casters 115, 125, and is disposed pivotally on the corresponding drive wheel frame 114.
- the driving unit 15 includes an electric motor 151 installed on the corresponding drive wheel frame 114 and operable to rotate the corresponding drive wheel 14.
- the return spring unit 16 includes a front spring 162 interconnecting the corresponding front mainframe 112 and the corresponding front connecting frame 123, and a rear spring 162' interconnecting the corresponding drive wheel frame 114 and the corresponding rear mainframe 122.
- the front and rear springs 162, 162' are stretched so as to allow the front caster 115 to rise relative to the drive wheel 14 and the rear caster 125.
- the front and rear springs 162, 162' return to their original shapes so as to allow the front caster 115 to contact a top surface of the obstacle 200.
- the load ratios of the front casters 115, the rear casters 125 and the drive wheels 14 are respectively 18.9%, 11.6% and 69.5%; after the front casters 115 surmount the obstacle 200 and before the drive wheels 14 contact the obstacle 200, the load ratios of the front casters 115, the rear casters 125 and the drive wheels 14 are respectively 16.9%, 26.8% and 56.3%; after the front casters 115 surmount the obstacle 200 and when the drive wheels 14 contact the obstacle 200, the load ratios of the front casters 115, the rear casters 125 and the drive wheels 14 are respectively 21.4%, 34.2% and 44.4%; after the drive wheels 14 surmount the obstacle 200 and before the rear casters 125 contact the obstacle 200, the load ratios of the front casters 115, the rear casters 125 and the drive wheels 14 are respectively 9.9%, 24.6% and 65.5%; after the drive
- the load ratio of the front casters 115 is only 0.3%. Since load ratio is proportional to the anti-tip and supporting ability of a wheel or caster, the wheelchair 100 tends to tip or become unstable after the drive wheels 14 surmount the obstacle 200, and when the rear casters 125 contact the obstacle 200.
- the object of this invention is to provide a wheelchair suspension that includes a front caster, which is connected to other elements in a specific manner so as to have a large load ratio, thereby promoting the anti-tip and supporting ability of the front caster.
- a side frame assembly for a wheelchair suspension includes a mainframe, and a front caster frame connected pivotally to both a front end of the mainframe and a front caster.
- a return spring is disposed between the front caster frame and the mainframe so as to bias the front caster to a predetermined position.
- a drive wheel assembly includes a drive wheel frame, a drive wheel disposed pivotally on the drive wheel frame, and a driving unit operable to rotate the drive wheel.
- a linkage is connected pivotally to the mainframe, the front caster frame and the drive wheel frame.
- a rear caster assembly includes a rear caster frame attached to a rear end of the mainframe, and a rear caster disposed pivotally on the rear caster frame.
- a wheelchair suspension of this invention is incorporated in an electric wheelchair, and includes two side frame assemblies. Because the two side frame assemblies are similar in construction to each other, the structure and operation of only one side frame assembly will be described.
- a side frame assembly 2 of the preferred embodiment of a wheelchair suspension according to this invention includes a mainframe 3, a front caster assembly 4, an inclined return spring 5, a drive wheel assembly 6, a linkage 7 and a rear caster 8.
- the mainframe 3 has a front connecting section 311, a rear connecting section 312, and a middle section 313 interconnecting the front and rear connecting sections 311, 312 and supporting a seat (not shown) thereon.
- the front caster assembly 4 includes a front caster frame 41 and a front caster 42.
- the front caster frame 41 has an upper end connected pivotally to a front end of the front connecting section 311 of the mainframe 3 at a first pivot point (P1), and a lower end connected pivotally to the front caster 42.
- the return spring 5 is configured as a coiled compression spring that has a rear upper end fastened to the front connecting section 311 of the mainframe 31, and a front lower end fastened to the front caster frame 41. As such, the return spring 5 biases the front caster 42 to a predetermined position relative to the mainframe 3.
- the drive wheel assembly 6 is disposed behind the front caster assembly 4, and includes a drive wheel frame 61, a drive wheel 62 disposed pivotally on the drive wheel frame 61, and a driving unit 63 including an electric motor 631 operable to rotate the drive wheel 62.
- the linkage 7 includes a generally horizontal front link 71 and an inclined rear link 72.
- the front link 71 has a front end connected pivotally to the front caster frame 41 at a second pivot point (P2), and a rear end connected pivotally to an end of the drive wheel frame 61 at a third pivot point (P3).
- the drive wheel frame 61 extends rearwardly and downwardly from the third pivot point (P3).
- the first pivot point (P1) is disposed in front of and above the second pivot point (P2).
- the rear link 72 extends forwardly and downwardly from the mainframe 3, and has a front end connected pivotally to the rear end of the front link 71 at the third pivot point (P3), and a rear end connected pivotally to the front connecting section 311 of the mainframe 3 at a fourth pivot point (P4).
- the rear caster assembly 8 includes a rear caster frame 81 attached fixedly to a rear end of the rear connecting section 312 of the mainframe 3 at an upper end thereof, and a rear caster 82 disposed pivotally on a lower end of the rear caster frame 81.
- the return spring 5 when the front caster 42 climbs over an obstacle 200 in the wheelchair's path, such as a stair, the return spring 5 is compressed. After the front caster 42 surmounts the obstacle 200, the return spring 5 returns to its original shape so as to bring the front caster 42 into contact with a top surface of the obstacle 200, thereby preventing the tipping of the electric wheelchair.
- a radius of each of the front and rear casters 42, 82 of 75mm a distance between the axles of the front and rear casters 42, 83 of 668mm, a radius of the drive wheel 62 of 130mm, a person sitting on the electric wheelchair weighing 70 kilograms, and a total weight of the remaining portion of the electric wheelchair supported by the drive wheel 62 and the front and rear casters 42, 82 of 74 kilograms.
- the angle changes of the seat of the electric wheelchair incorporating the suspension of this invention are smaller than those of the conventional wheelchair shown in Fig. 1, regardless of the height of the obstacle 200. As such, the anti-tip effect of the wheelchair suspension is increased.
- the load ratios of the front casters 42, the rear casters 82 and the drive wheels 62 are respectively 27.9%, 11.9% and 60.2%; after the front casters 42 surmount the obstacle 200 and before the drive wheels 42 contact the obstacle 200, the load ratios of the front casters 42, the rear casters 82 and the drive wheels 62 are respectively 17.6%, 26.7% and 55.7%; after the front casters 42 surmount the obstacle 200 and when the drive wheels 62 contact the obstacle 200, the load ratios of the front casters 42, the rear casters 82 and the drive wheels 62 are respectively 22.3%, 34.3% and 43.4%; after the drive wheels 62 surmount the obstacle 200 and before the rear casters 82 contact the obstacle 200, the load ratios of the front casters 42, the rear casters 82 and the drive wheels 62 are respectively 25.9%, 36.9% and 37.2%; after the drive
- the load ratios of each of the front casters 42, the rear casters 82, and the drive wheels 62 are in all instances greater than 10%, thereby resulting in an increase in the anti-tip and supporting ability of the wheel or caster. This improves the safety and comfort of the electric wheelchair when encountering an obstacle.
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- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Animal Behavior & Ethology (AREA)
- General Health & Medical Sciences (AREA)
- Public Health (AREA)
- Veterinary Medicine (AREA)
- Handcart (AREA)
Abstract
A side frame assembly (2) for a wheelchair suspension includes a mainframe (3), and a front caster frame (41) connected pivotally to both a front end of the mainframe (3) and a front caster (42). A return spring (5) is disposed between the front caster frame (41) and the mainframe (3) so as to bias the front caster (42) to a predetermined position. A drive wheel assembly (6) includes a drive wheel frame (61), a drive wheel (62) disposed pivotally on the drive wheel frame (61), and a driving unit (63) operable to rotate the drive wheel (62). A linkage (7) is connected pivotally to the mainframe (3), the front caster frame (41) and the drive wheel frame (61). A rear caster assembly (8) includes a rear caster frame (81) attached to a rear end of the mainframe (3), and a rear caster (82) disposed pivotally on the rear caster frame (81).
Description
- This invention relates to a wheelchair, and more particularly to a wheelchair suspension.
- Referring to Figs. 1 and 2, a conventional suspension disclosed in
U.S. Patent Application Publication No. 2004/0060748 A1 is incorporated in awheelchair 100, and has twoside frame assemblies 1, each of which includes afront caster assembly 11, arear caster assembly 12, alinkage 13, adrive wheel 14, adriving unit 15 and areturn spring unit 16. - The
front caster assembly 11 includes afront mainframe 112, afront caster frame 113 extending downwardly from a front end of thefront mainframe 112, adrive wheel frame 114 extending downwardly from a rear end of thefront mainframe 112, and afront caster 115 disposed pivotally on a lower end of thefront caster frame 113. - The
rear caster assembly 12 includes arear mainframe 122, a front connectingframe 123 extending downwardly from a front end of therear mainframe 122, arear caster frame 124 extending downwardly from a rear end of therear mainframe 122, and arear caster 125 disposed pivotally on a lower end of therear caster frame 124. Therear mainframe 122 cooperates with thefront mainframe 112 to support aseat 300. - The
linkage 13 has two ends connected respectively and pivotally to thefront caster frame 113 and the front connectingframe 123. - The
drive wheel 14 has a diameter greater than those of the front andrear casters drive wheel frame 114. - The
driving unit 15 includes anelectric motor 151 installed on the correspondingdrive wheel frame 114 and operable to rotate thecorresponding drive wheel 14. - The
return spring unit 16 includes afront spring 162 interconnecting the correspondingfront mainframe 112 and the correspondingfront connecting frame 123, and a rear spring 162' interconnecting the correspondingdrive wheel frame 114 and the correspondingrear mainframe 122. - Referring to Figs. 2 and 3, because of the presence of the front and
rear springs 162, 162', thedrive wheel 14 and the front andrear casters - Referring to Fig. 4, when the
front caster 115 climbs over anobstacle 200 in the wheelchair's path, such as a stair, the front andrear springs 162, 162' are stretched so as to allow thefront caster 115 to rise relative to thedrive wheel 14 and therear caster 125. After therear caster 125 surmounts theobstacle 200, the front andrear springs 162, 162' return to their original shapes so as to allow thefront caster 115 to contact a top surface of theobstacle 200. - To test the
wheelchair 100, the following parameters were used: a radius of each of the front andrear casters front casters 115 and therear casters 125 of 668mm, a radius of each of thedrive wheels 14 of 130mm, a person sitting on thewheelchair 100 weighing 70 kilograms, and a total weight of the remaining portion of thewheelchair 100 supported by the front andrear casters drive wheels 14 of 74 kilograms. When thefront casters 115 surmountdifferent obstacles 200, corresponding inclination angle changes of theseat 300 of thewheelchair 100 are as outlined in the following chart:Obstacle Height (mm) 10 20 30 40 50 60 Angle Change(degrees) 1.26 2.54 3.83 5.13 6.44 7.77 - In the case where the height of the
obstacle 200 is 50mm, when thefront casters 115 contact theobstacle 200, the load ratios of thefront casters 115, therear casters 125 and thedrive wheels 14 are respectively 18.9%, 11.6% and 69.5%; after thefront casters 115 surmount theobstacle 200 and before thedrive wheels 14 contact theobstacle 200, the load ratios of thefront casters 115, therear casters 125 and thedrive wheels 14 are respectively 16.9%, 26.8% and 56.3%; after thefront casters 115 surmount theobstacle 200 and when thedrive wheels 14 contact theobstacle 200, the load ratios of thefront casters 115, therear casters 125 and thedrive wheels 14 are respectively 21.4%, 34.2% and 44.4%; after thedrive wheels 14 surmount theobstacle 200 and before therear casters 125 contact theobstacle 200, the load ratios of thefront casters 115, therear casters 125 and thedrive wheels 14 are respectively 9.9%, 24.6% and 65.5%; after thedrive wheels 14 surmount theobstacle 200 and when therear casters 125 contact theobstacle 200, the load ratios of thefront casters 115, therear casters 125 and thedrive wheels 14 are respectively 0.3%, 23.5% and 76.2%; and after therear casters 125 surmount theobstacle 200, the load ratios of thefront casters 115, therear casters 125 and thedrive wheels 14 are respectively 15.4%, 21. 9% and 62.7%. - As indicated by the test data in the chart that, even when the height of the
obstacle 200 is 60mm, the inclination angle change of the seat is only 7.77°. This poses no safety risk and provides no feeling of discomfort to the person sitting on thewheelchair 100. - In the case where the
obstacle 200 is 50mm high, however, after thedrive wheels 14 surmount theobstacle 200, and when therear casters 125 contact theobstacle 200, the load ratio of thefront casters 115 is only 0.3%. Since load ratio is proportional to the anti-tip and supporting ability of a wheel or caster, thewheelchair 100 tends to tip or become unstable after thedrive wheels 14 surmount theobstacle 200, and when therear casters 125 contact theobstacle 200. - The object of this invention is to provide a wheelchair suspension that includes a front caster, which is connected to other elements in a specific manner so as to have a large load ratio, thereby promoting the anti-tip and supporting ability of the front caster.
- According to this invention, a side frame assembly for a wheelchair suspension includes a mainframe, and a front caster frame connected pivotally to both a front end of the mainframe and a front caster. A return spring is disposed between the front caster frame and the mainframe so as to bias the front caster to a predetermined position. A drive wheel assembly includes a drive wheel frame, a drive wheel disposed pivotally on the drive wheel frame, and a driving unit operable to rotate the drive wheel. A linkage is connected pivotally to the mainframe, the front caster frame and the drive wheel frame. A rear caster assembly includes a rear caster frame attached to a rear end of the mainframe, and a rear caster disposed pivotally on the rear caster frame.
- These and other features and advantages of this invention will become apparent in the following detailed description of a preferred embodiment of this invention, with reference to the accompanying drawings, in which:
- Fig. 1 is a perspective view of a conventional electric wheelchair;
- Fig. 2 is a side view of a side frame assembly of a suspension of the conventional electric wheelchair;
- Fig. 3 is a schematic side view of the side frame assembly of the suspension of the conventional electric wheelchair, illustrating how the wheelchair moves on a horizontal surface;
- Fig. 4 is a schematic side view of the side frame assembly of the suspension of the conventional electric wheelchair, illustrating how a front caster climbs over an obstacle;
- Fig. 5 is a side view of a side frame assembly of the preferred embodiment of a wheelchair suspension according to this invention;
- Fig. 6 is a schematic side view of the preferred embodiment when it moves on a horizontal surface; and
- Fig. 7 is a schematic side view of the preferred embodiment when a front caster climbs over an obstacle.
- A wheelchair suspension of this invention is incorporated in an electric wheelchair, and includes two side frame assemblies. Because the two side frame assemblies are similar in construction to each other, the structure and operation of only one side frame assembly will be described.
- Referring to Fig. 5, a
side frame assembly 2 of the preferred embodiment of a wheelchair suspension according to this invention includes amainframe 3, afront caster assembly 4, aninclined return spring 5, adrive wheel assembly 6, alinkage 7 and arear caster 8. - The
mainframe 3 has a front connectingsection 311, a rear connectingsection 312, and amiddle section 313 interconnecting the front and rear connectingsections - With additional reference to Fig. 6, the
front caster assembly 4 includes afront caster frame 41 and afront caster 42. Thefront caster frame 41 has an upper end connected pivotally to a front end of the front connectingsection 311 of themainframe 3 at a first pivot point (P1), and a lower end connected pivotally to thefront caster 42. - The
return spring 5 is configured as a coiled compression spring that has a rear upper end fastened to the front connectingsection 311 of themainframe 31, and a front lower end fastened to thefront caster frame 41. As such, thereturn spring 5 biases thefront caster 42 to a predetermined position relative to themainframe 3. - The
drive wheel assembly 6 is disposed behind thefront caster assembly 4, and includes adrive wheel frame 61, adrive wheel 62 disposed pivotally on thedrive wheel frame 61, and adriving unit 63 including anelectric motor 631 operable to rotate thedrive wheel 62. - The
linkage 7 includes a generallyhorizontal front link 71 and an inclinedrear link 72. Thefront link 71 has a front end connected pivotally to thefront caster frame 41 at a second pivot point (P2), and a rear end connected pivotally to an end of thedrive wheel frame 61 at a third pivot point (P3). Thedrive wheel frame 61 extends rearwardly and downwardly from the third pivot point (P3). The first pivot point (P1) is disposed in front of and above the second pivot point (P2). Therear link 72 extends forwardly and downwardly from themainframe 3, and has a front end connected pivotally to the rear end of thefront link 71 at the third pivot point (P3), and a rear end connected pivotally to the front connectingsection 311 of themainframe 3 at a fourth pivot point (P4). - The
rear caster assembly 8 includes arear caster frame 81 attached fixedly to a rear end of the rear connectingsection 312 of themainframe 3 at an upper end thereof, and arear caster 82 disposed pivotally on a lower end of therear caster frame 81. - When the wheelchair suspension moves on a horizontal surface, because the
return spring 5 biases thefront caster 42 to the predetermined position, a lower end of thefront caster 42 can be aligned with lower ends of thedrive wheel 62 and therear caster 82. - Referring to Fig. 7, when the
front caster 42 climbs over anobstacle 200 in the wheelchair's path, such as a stair, thereturn spring 5 is compressed. After thefront caster 42 surmounts theobstacle 200, thereturn spring 5 returns to its original shape so as to bring thefront caster 42 into contact with a top surface of theobstacle 200, thereby preventing the tipping of the electric wheelchair. - To test the wheelchair suspension, the following parameters are used: a radius of each of the front and
rear casters rear casters 42, 83 of 668mm, a radius of thedrive wheel 62 of 130mm, a person sitting on the electric wheelchair weighing 70 kilograms, and a total weight of the remaining portion of the electric wheelchair supported by thedrive wheel 62 and the front andrear casters - When the
front casters 42 surmountdifferent obstacles 200, corresponding inclination angle changes of the seat of the electric wheelchair are as outlined in the following chart:Obstacle Height (mm) 10 20 30 40 50 60 Angle Change (degrees) 0.96 1.90 2.82 3.73 4.62 5.49 - As indicated by the data in this chart, the angle changes of the seat of the electric wheelchair incorporating the suspension of this invention are smaller than those of the conventional wheelchair shown in Fig. 1, regardless of the height of the
obstacle 200. As such, the anti-tip effect of the wheelchair suspension is increased. - In the case where the height of the
obstacle 200 is 50mm, when thefront casters 42 contact theobstacle 200, the load ratios of thefront casters 42, therear casters 82 and thedrive wheels 62 are respectively 27.9%, 11.9% and 60.2%; after thefront casters 42 surmount theobstacle 200 and before thedrive wheels 42 contact theobstacle 200, the load ratios of thefront casters 42, therear casters 82 and thedrive wheels 62 are respectively 17.6%, 26.7% and 55.7%; after thefront casters 42 surmount theobstacle 200 and when thedrive wheels 62 contact theobstacle 200, the load ratios of thefront casters 42, therear casters 82 and thedrive wheels 62 are respectively 22.3%, 34.3% and 43.4%; after thedrive wheels 62 surmount theobstacle 200 and before therear casters 82 contact theobstacle 200, the load ratios of thefront casters 42, therear casters 82 and thedrive wheels 62 are respectively 25.9%, 36.9% and 37.2%; after thedrive wheels 62 surmount theobstacle 200 and when therear casters 82 contact theobstacle 200, the load ratios of thefront casters 42, therear casters 82 and thedrive wheels 62 are respectively 23.6%, 50.0% and 26.4%; and after therear casters 82 surmount theobstacle 200, the load ratios of thefront casters 42, therear casters 82 and thedrive wheels 62 are respectively 23.8%, 48.2% and 28.0%. The load ratios of each of thefront casters 42, therear casters 82, and thedrive wheels 62 are in all instances greater than 10%, thereby resulting in an increase in the anti-tip and supporting ability of the wheel or caster. This improves the safety and comfort of the electric wheelchair when encountering an obstacle. - Furthermore, use of the
single spring 5 in theside frame assembly 2 results in a simple structure of the wheelchair, and therefore reduces the manufacturing costs of the wheelchair.
Claims (5)
- A side frame assembly (2) for a wheelchair suspension
characterized by:a mainframe (3);a front caster assembly (4) including a front caster frame (41) and a front caster (42), the front caster frame (41) having two opposite ends connected respectively and pivotally to a front end of the mainframe (3) and the front caster (42);a return spring (5) disposed between the front caster frame (41) and the mainframe (3) so as to bias the front caster (42) to a predetermined position relative to the mainframe (3);a drive wheel assembly (6) disposed behind the front caster assembly (4) and including a drive wheel frame (61), a drive wheel (62) disposed pivotally on the drive wheel frame (61), and a driving unit (63) operable to rotate the drive wheel (62);a linkage (7) connected pivotally to the mainframe (3), the front caster frame (41) and the drive wheel frame (61); anda rear caster assembly (8) including a rear caster frame (81) attached to a rear end of the mainframe (3), and a rear caster (82) disposed pivotally on the rear caster frame (81). - The side frame assembly (2) as claimed in Claim 1, characterized in that the return spring (5) is configured as a coiled compression spring that is inclined and that has a rear upper end fastened to the mainframe (3), and a front lower end fastened to the front caster frame (41) .
- The side frame assembly (2) as claimed in Claim 1, characterized in that the front caster frame (41) is connected pivotally to the mainframe (3) at a first pivot point (P1), the linkage (7) including:a front link (71) having a front end connected pivotally to the front caster frame (41) at a second pivot point (P2), and a rear end connected pivotally to an end of the drive wheel frame (61) at a third pivot point (P3); andan inclined rear link (72) having a front end connected pivotally to the rear end of the front link (71) at the third pivot point (P3), and a rear end connected pivotally to the mainframe (3) at a fourth pivot point (P4).
- The side frame assembly (2) as claimed in Claim 3, further characterized in that the first pivot point (P1) is disposed in front of and above the second pivot point (P2).
- The side frame assembly (2) as claimed in Claim 3, further characterized in that the front link (71) is generally horizontal, the rear link (72) extending forwardly and downwardly from the mainframe (3), the drive wheel frame (61) extending rearwardly and downwardly from the third pivot point (P3).
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP05020625A EP1767178A1 (en) | 2005-09-22 | 2005-09-22 | Wheelchair suspension |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
EP05020625A EP1767178A1 (en) | 2005-09-22 | 2005-09-22 | Wheelchair suspension |
Publications (1)
Publication Number | Publication Date |
---|---|
EP1767178A1 true EP1767178A1 (en) | 2007-03-28 |
Family
ID=35745995
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP05020625A Withdrawn EP1767178A1 (en) | 2005-09-22 | 2005-09-22 | Wheelchair suspension |
Country Status (1)
Country | Link |
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EP (1) | EP1767178A1 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8177257B2 (en) | 2007-05-08 | 2012-05-15 | Eric Dugas | Wheelchair base |
US8210556B2 (en) | 2005-08-18 | 2012-07-03 | Sunrise Medical Hhg, Inc. | Midwheel drive wheelchair with independent front and rear suspension |
US8851214B2 (en) | 2010-07-15 | 2014-10-07 | Permobil Ab | Electric mid-wheel drive wheelchair |
CN109823443A (en) * | 2019-03-19 | 2019-05-31 | 浙江欣奕华智能科技有限公司 | A kind of robot chassis with overturn-preventing structure |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6129165A (en) * | 1996-07-03 | 2000-10-10 | Pride Mobility Products, Corporation | Curb-climbing power wheelchair |
US20040060748A1 (en) * | 2001-10-10 | 2004-04-01 | Molnar James H. | Wheelchair suspension |
US20050077714A1 (en) * | 2003-10-08 | 2005-04-14 | Mulhern James P. | Anti-tip system for wheelchairs |
-
2005
- 2005-09-22 EP EP05020625A patent/EP1767178A1/en not_active Withdrawn
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US6129165A (en) * | 1996-07-03 | 2000-10-10 | Pride Mobility Products, Corporation | Curb-climbing power wheelchair |
US20040060748A1 (en) * | 2001-10-10 | 2004-04-01 | Molnar James H. | Wheelchair suspension |
US20050077714A1 (en) * | 2003-10-08 | 2005-04-14 | Mulhern James P. | Anti-tip system for wheelchairs |
Cited By (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US8210556B2 (en) | 2005-08-18 | 2012-07-03 | Sunrise Medical Hhg, Inc. | Midwheel drive wheelchair with independent front and rear suspension |
US8177257B2 (en) | 2007-05-08 | 2012-05-15 | Eric Dugas | Wheelchair base |
US8851214B2 (en) | 2010-07-15 | 2014-10-07 | Permobil Ab | Electric mid-wheel drive wheelchair |
US9320661B2 (en) | 2010-07-15 | 2016-04-26 | Permobil Ab | Electric mid-wheel drive wheelchair |
CN109823443A (en) * | 2019-03-19 | 2019-05-31 | 浙江欣奕华智能科技有限公司 | A kind of robot chassis with overturn-preventing structure |
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