초록 ▼

A roller device (7) for equipment such as a ladder (5) has a rigid core (14) with an axle (17), and a surrounding more compressible rubber portion (8,9) circumferentially spaced portions of which are more readily compressible than adjacent portions so that the device will roll easily when not under

A roller device (7) for equipment such as a ladder (5) has a rigid core (14) with an axle (17), and a surrounding more compressible rubber portion (8,9) circumferentially spaced portions of which are more readily compressible than adjacent portions so that the device will roll easily when not under load, but less easily when under load.

대표청구항 ▼

A device fitted, or arranged to be fitted, to loadable equipment, which is occasionally movable over a supporting surface (18) when unloaded, the device comprising at least one roller (7) for rolling over the surface, the roller having portions of different compressibility around its circumference,

A device fitted, or arranged to be fitted, to loadable equipment, which is occasionally movable over a supporting surface (18) when unloaded, the device comprising at least one roller (7) for rolling over the surface, the roller having portions of different compressibility around its circumference, whereby when resting under a first, lighter loading against the surface the roller will roll easily over that surface, but when the equipment is under load and the roller is forced under a second, heavier loading against the surface a more compressible portion of the roller can flatten more closely towards the axis of the roller than an adjacent less compressible portion thereby impeding rolling.