| 摘要 |
A description is given of a prefabricated concrete compound unit for spiral staircases, having a central ring 1 and a tread panel 2 projecting from the same, it being the case that the tread panel 2 is of a thickness which corresponds to just part of the height of the ring 1, and a vertical web 3 is connected to the tread panel 2, it being the case that the height of the unit comprising tread panel 2 and vertical web 3 is equal to the height of the ring 1. <IMAGE> |
