| 摘要 |
The step ladder has corner castor wheels (2) spring-loaded in their contact with the floor. The spring component force is such that the force of gravity of the ladder added to that of a person standing on it overcomes the spring force and brings a static support system (3) in contact with the ground. - The construction provides an easily movable domestic step ladder with a built-in safety device ensuring stability when being used.(1) |
