Patent ID: 7438282
Filing Date: 2008-10-21
Classification: E04F

Abstract:
1. In combination: a tube having an open end and an inside cylindrical wall, and a ball knob adapted to be secured to a support, said ball knob comprising a spherical body having a top surface, an annular convex curved side wall, said side wall having an outer annular section adjacent the top surface, said annular section having a downwardly and outwardly curved annular tapered shape with a diameter smaller than the diameter of the inside cylindrical wall of the tube whereby the annular section aligns and guides the tube as the tube is telescoped onto the ball knob, a hole extended through the body for accommodating a fastener adapted to secure the knob to the support, and a plurality of laterally spaced and outwardly extended continuous flexible annular ribs on the annular convex curved side wall of the body, said ribs extending completely around the annular convex curved side wall of the body, said inside cylindrical wall of the tube being telescoped around the convex curved side wall of the body with the annular ribs deformed to bias the ribs into annular sealing engagement with the inside cylindrical wall of the tube.