Extendible and retractable cover apparatus for swimming pools
United States Patent 3050743
Publication Date:
08/28/1962
Assignee:
Philip, Mallinckrodt A.
Other Classes:
135/904, 192/93R, 192/51, 160/310, 135/903, 135/96, 160/271
International Classes:
E04H4/10; E04H4/00