Patent ID: 9718308
Date: 2017-08-01
CPC Classifications: A45C,B60B,Y10T

Claim:
1. A castor comprising: a wheel support; at least one roller mounted on the wheel support; and a shaft extending through the wheel support and the at least one roller so that the at least one roller is rotatable freely on the wheel support; wherein: the at least one roller has a peripheral portion provided with a hollow air chamber having an annular arrangement; the hollow air chamber has an inner diameter provided with a plurality of hollow air columns which are arranged in a radiating manner and are equally distant from each other; one of the plurality of hollow air columns is provided with an air inlet; the at least one roller has an inner portion provided with a circumferential face which has a center provided with a seat which has a center provided with a shaft hole pivotally mounted on the shaft; the seat has a hollow cylindrical shape and extends outward; the at least one roller is made of soft material; the soft material is PU (polyurethane) with a specific weight of 95 to 115; and a gas is filled into the soft material via the air inlet to shape the soft material to form the at least one roller.