| 摘要 |
<p>An umbrella tent construction includes a plurality of elongated resilient ribs each pivoted at one end to the flange portion of a top base member which includes a vertical post portion projecting downward from the flange. A brace is pivoted at one end to each rib intermediate the ends of the latter, and the opposite end of the braces are pivoted to a hub disposed vertically below the base member. The hub is movable vertically toward and away from the base member across a plane extending through the axes of the pivot connections of the braces to the ribs, to effect opening and closing of the ribs. Abutment means operatively interengages the base member and hub in a predetermined position of the latter above said plane, to limit the upward movement of the hub toward the base member and thus establish the open condition of the ribs. A flexible tent cover is secured to the ribs and is stretched tight as the ribs move toward said open position. The stretched cover resiliently resists vertical movement of the hub upward across said plane, whereby the hub snaps upwardly across said plane to said open position of the ribs in which the abutment means interengages the base and hub. The stretched cover thus locks the hub in said open condition. By pulling the hub downward across said plane, against the resistance of the stretched cover, the hub and braces are unlocked, whereupon the braces and ribs are collapsed to tent-folding condition.</p> |
