Back to results
US 4,290,618 AGranted
Hand truck stair tread engaging device
AssigneeClamor Company
InventorJohn C. Morton
Life of this patent
Estimating the term…
Abstract
In a conventional hand truck, a stair tread engaging device having reduced friction and improved mobility provided by a plurality of rollers each rotating freely in its own socket and only on its own axis without forward movement.
Claims12
In a hand truck assembly having a wheel and handled frame, including side members, a tread engaging device secured to one of the side members of the frame, said tread engaging device including an endless V-belt for engaging the tread of a stairs and roller means thereon, the improvement which comprises:
- said roller means including a plurality of barrell-shaped rollers having flat end walls and a bulging sidewall, each of said rollers being mounted in an individual cavity in said device and rotatable about their own axes, said rollers being generally linearly aligned and non-linearly movable with respect to said device, with said V-belt making full contact with more than one of said rollers only when said V-belt abuts against a generally flatsurface and said rollers, and making contact with only one of said rollers when a portion of said V-belt engages the edge of a stair and impacts against said only one of said rollers, said tread engaging device further including flange means at each of the two ends thereof to maintain said V-belt on said device.
A stair tread engaging device adapted to be be mounted on a hand truck, said device comprising
- an elongated main body formed by a pair of mating body sections each of said body sections having means thereon cooperating to form a plurality of linearly aligned generally circular cavities along only one elongated generally linear side of said main body, each of said cavities opening outwardly of said main body and a barrel shaped second roller, having flat end walls and a bulging sidewall, freely rotatably mounted about its own axis in each of said cavities, said mating body sections forming a peripheral groove around said body, said mating body sections also forming flange means at both ends of said body, said groove having a resilient endless belt mounted therein, said belt being retained by both of said flange means, said belt engaging said rollers when said belt is pressed against said rollers, and a pair of spaced belt engaging first rollers at opposite ends of said main body rotably mounted therein engaging said belt for rotating said belt;
- said first rollers being disposed above and outwardly from said second rollers.
Dependencies are inferred from the claim text.