Patent 7891031 Issued on February 22, 2011. Estimated Expiration Date: July 20, 2026. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
A deck construction includes a movable, rigid, unitary platform with wheels mounted to its bottom and supporting tracks arranged on opposite sides of an open space below the platform. The wheels roll along the tracks, allowing horizontal movement of the platform. At least one drive mechanism is mounted on a side of the open space to engage a rack on the platform. One or more stationary sources of rotary power, such as electric motors, operate the drive mechanism to cause the platform to move horizontally in either direction along the tracks. The deck construction is particularly useful as a swimming pool cover or an extensible balcony or canopy.
Dripool, webpage www.dripool.co.uk/automatic—covers.html, dated Sep. 27, 2005, one page.