Ball Joint Base and Twist Lock for Slideable Concentric Members Adapted for Use in Umbrellas with Extensible Canopy Ribs

Abstract

A twist lock mechanism for easily achieving a secure locking relationship between an outer member and an inner member is provided for use on an umbrella with a ball-joint based for adaptive orientation, and a spike receiving base or anchoring base mechanism.

I claim: 
     
         1 . An umbrella comprising:
 a canopy supported by a plurality of ribs;   a pole having an upper end carrying the canopy;   a pole having a lower end connected to a base;   stretchers extending outward from a pole and supporting the plurality of ribs;   a twist lock for engaging concentric sliding members.   
     
     
         2 . The umbrella of  claim 1  wherein the twist lock mechanism comprises a first exterior member overfitting a second interior member wherein the tightening of top and bottom cap members on the first exterior member urge a lock ring held within the top cap into angled engagement with the second interior member, fixing its position relative to the first exterior member. 
     
     
         3 . The umbrella of  claim 1  wherein the twist lock mechanism on a first exterior member comprises:
 a top cap threaded on the interior to receive a bottom cap threaded on the exterior and having a downward facing normal interior surface and downward facing inclined interior surface; 
 a base support received within the top cap having an upward facing normal surface below the downward facing inclined interior surface and upward facing inclined surface below the downward facing normal interior surface; 
 a lock ring biased to a normal position intermediate the upward and downward facing surfaces; 
 a longitudinally moveable post extendable through the upward facing normal surface; and the bottom cap having an upward facing portion that restrains and pushes on a base of the post. 
 
     
     
         4 . The umbrella of  claim 1  wherein the base has a ball joint. 
     
     
         5 . The umbrella of  claim 1  wherein the base has a plurality of openings that receive spikes. 
     
     
         6 . The umbrella of  claim 1  wherein the base has an anchor.