| 摘要 |
A system is disclosed for facilitating rotation of a mattress in a horizontal plane carried by a box spring or a platform. Surfaces between the mattress and the box spring or platform are selectively placed in engagement with each other. The surfaces may be provided by two separate covers; a single cover and the inherent surface roughness of the box spring or fixed or adjustable platform; a single cover with an embedded surface or no covers with embedded surfaces in both the mattress and the box spring or platform. In the latter embodiment, the mattress and the box spring or platform are secured together in a normal mode of operation to prevent unintended movement of the mattress. |
