A laterally collapsible, user-pushed, four-wheeled rollator, stroller or the like has swiveling front wheels for steering, each mounted in a fork with a vertical post, with a toothed pulley fixed thereto, rotatable in a bearing housing fixed at the front end of right and left side frames. The two sw
A laterally collapsible, user-pushed, four-wheeled rollator, stroller or the like has swiveling front wheels for steering, each mounted in a fork with a vertical post, with a toothed pulley fixed thereto, rotatable in a bearing housing fixed at the front end of right and left side frames. The two swiveling front wheels can swivel to any steering angle but always in unison with each other by virtue of a flexible toothed synchronous belt extending between the toothed pulleys. The interior of each bearing housing closely surrounds each toothed pulley and the belt, preventing any disengagement of the belt from either toothed pulley even when the belt becomes slack when the left and right side frames are folded towards each other. A synchronous chain with sprockets can also be used. Tether means pull the belt/chain rearwardly to a protected position during folding.
대표청구항▼
1. A collapsible hand-propelled wheeled support or carrier, such as a rollator, walker, pushchair or stroller, comprising: a) left and right side frames each supporting at least individual front and rear wheels;b) each of said front wheels being mounted on a vertical post and swivelable about a vert
1. A collapsible hand-propelled wheeled support or carrier, such as a rollator, walker, pushchair or stroller, comprising: a) left and right side frames each supporting at least individual front and rear wheels;b) each of said front wheels being mounted on a vertical post and swivelable about a vertical axis;c) toothed pulleys fixedly mounted one on each post;d) a flexible toothed synchronous belt engaging each toothed pulley and extending between them;e) folding struts extending between said left and right side frames, permitting moving said left and right frames laterally towards each other to a collapsed or folded storage position and away from each other to an expanded or folded-out stable position for use of the wheeled support or carrier; andf) journal bearing housings fixedly mounted on each of said left and right frames and each swivelably holding one each of said vertical posts with said toothed pulley fixedly mounted on said vertical post, each of said journal bearing housings surrounding said toothed synchronous belt in such close proximity and circumferential extent as to prevent any disengagement or slippage between said synchronous belt and the toothed pulleys. 2. The wheeled support or carrier according to claim 1, wherein said folding struts extending between said left and right side frames comprise a centrally pivoted scissors arrangement. 3. The wheeled support or carrier according to claim 1, wherein said folding struts extending between said left and right side frames comprise a centrally hinged vertical brace frames. 4. The wheeled support or carrier according to claim 1, wherein each of said front wheels is rollably mounted on its vertical post via a fork fixed to said vertical swivel post. 5. The wheeled support or carrier according to claim 1, wherein each of said front wheels is unlimitedly swivelable about a vertical axis. 6. The wheeled support or carrier according to claim 1, wherein said synchronous belt is tethered to a point or points on said folding struts, which moves or move upwards as the wheeled support or carrier is folded up, said tether comprising a loose loop or ring through which the synchronous belt freely runs and a tether cord passing through or attached to said loop or ring, whereby the midpoint of said synchronous belt is pulled rearward as the wheeled support or carrier is folded up. 7. The wheeled support or carrier according to claim 6, wherein said ring, through which the synchronous belt runs, is in the form of a rigid frame freely rotatably holding within it an externally toothed wheel engaging on diametrically opposite sides said synchronous belt. 8. The wheeled support or carrier according to claim 2, wherein each of said front wheels is unlimitedly swivelable about a vertical axis. 9. The wheeled support or carrier according to claim 3, wherein each of said front wheels is unlimitedly swivelable about a vertical axis. 10. The wheeled support or carrier according to claim 4, wherein each of said front wheels is unlimitedly swivelable about a vertical axis. 11. The wheeled support or carrier according to claim 2, wherein said synchronous belt is tethered to a point or points on said folding struts, which moves or move upwards as the wheeled support or carrier is folded up, said tether comprising a loose loop or ring through which the synchronous belt freely runs and a tether cord passing through or attached to said loop or ring, whereby the midpoint of said synchronous belt is pulled rearward as the wheeled support or carrier is folded up. 12. The wheeled support or carrier according to claim 3, wherein said synchronous belt is tethered to a point or points on said folding struts, which moves or move upwards as the wheeled support or carrier is folded up, said tether comprising a loose loop or ring through which the synchronous belt freely runs and a tether cord passing through or attached to said loop or ring, whereby the midpoint of said synchronous belt is pulled rearward as the wheeled support or carrier is folded up. 13. The wheeled support or carrier according to claim 4, wherein said synchronous belt is tethered to a point or points on said folding struts, which moves or move upwards as the wheeled support or carrier is folded up, said tether comprising a loose loop or ring through which the synchronous belt freely runs and a tether cord passing through or attached to said loop or ring, whereby the midpoint of said synchronous belt is pulled rearward as the wheeled support or carrier is folded up. 14. A collapsible hand-propelled wheeled support or carrier, such as a rollator, walker, pushchair or stroller, comprising: a) left and right side frames each supporting at least individual front and rear wheels;b) each of said front wheels being mounted on a vertical post and swivelable about a vertical axis;c) sprockets fixedly mounted one on each post;d) a flexible synchronous chain engaging each sprocket and extending between them;e) folding struts extending between said left and right side frames, permitting moving said left and right frames laterally towards each other to a collapsed or folded storage position and away from each other to an expanded or folded-out stable position for use of the wheeled support or carrier; andf) journal bearing housings fixedly mounted on each of said left and right frames and each swivelably holding one each of said vertical posts with said sprocket fixedly mounted on said vertical post, each of said journal bearing housings surrounding said synchronous chain in such close proximity and circumferential extent as to prevent any disengagement or slippage between said synchronous chain and the sprockets. 15. The wheeled support or carrier according to claim 14, wherein said folding struts extending between said left and right side frames comprise a centrally pivoted scissors arrangement. 16. The wheeled support or carrier according to claim 14, wherein said folding struts extending between said left and right side frames comprise a centrally hinged vertical brace frames. 17. The wheeled support or carrier according to claim 14, wherein each of said front wheels is rollably mounted on its vertical post via a fork fixed to said vertical swivel post. 18. The wheeled support or carrier according to claim 14, wherein each of said front wheels is unlimitedly swivelable about a vertical axis. 19. The wheeled support or carrier according to claim 14, wherein said synchronous chain is tethered to a point or points on said folding struts, which moves or move upwards as the wheeled support or carrier is folded up, said tether comprising a loose loop or ring through which the synchronous chain freely runs and a tether cord passing through or attached to said loop or ring, whereby the midpoint of said synchronous chain is pulled rearward as the wheeled support or carrier is folded up. 20. The wheeled support or carrier according to claim 19, wherein said ring, through which the synchronous chain runs, is in the form of a rigid frame freely rotatably holding within it an externally toothed wheel engaging on diametrically opposite sides said synchronous chain.
Fernie Geoffrey R. (29 Blaketon Road Etobicoke ; Ontario CAX M9B 4W4) Doyle Brian P. (36 High Park Avenue Toronto ; Ontario CAX M6P 2R9) Griggs Gerald T. (77 Shrewbury Square Scarborough ; Ontario CA, Walking aid.
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