On May 10, 11:38*pm, Don Foreman
wrote:
On Sun, 10 May 2009 22:01:24 -0500, cavelamb
wrote:

You know those magic telescoping poles that can lock?

Useful for boat poles, spinnaker and jib poles, or changing light bulbs.

Anybody have a clue how these things work?

They're slightly elliptical, *so they sort of cam lock when the mating
parts are rotated relative to each other.

Just looked, it has two short plastic cylinders with identically
offset center holes, one piece pressed into the inner tube and the
other free to rotate on a screw. I use them for trimming branches and
cleaning the gutter. The lock holds well for endwise forces but not,
of course, to much twisting.

The ceiling painting pole with a lever-operated pin lock works
better.

jsw