US Patent 9388837 Telescoping tube assembly having twist lock

A twist-locking mechanism for two telescoping tubes, as may comprise a curtain rod, comprises a sleeve which expands outwardly as it moves along the screw of a screw body. A tapered or straight screw connects to a plain shaft portion upon which the sleeve rests when the device is in the unlock position. In another embodiment, the pitch or profile of the thread of a straight screw changes along the length of the screw, so the sleeve is forced radially outwardly as it moves from the unlock position. Split-sleeves useful in the locking mechanism have spring like features or an oblong shape, so the sleeve is biased outwardly to frictionally engage one the tube when the sleeve is at the unlock position.