How do telescoping/extendable/retractable poles work?
I'm talking about the long poles usually used by landscapers as pole saws to cut palms and such. I know some have a twist and some have a thing to flip up, but I was wondering what actually locks it in place (the mechanics of it)?
most of them use a cam mechanism. the ones with a lever have an off center knob so when you pull the lever over the cam squeezes the inner tube. on the twist ones. if you twist the whole pole there is an eccentric cam on the end of the inner pole when you turn it it jams tight into the outer tube. or if there is a collar that you turn to lock it, the inside of the collar is tapered, and the end of the tube is tapered and slotted, so as you tighten down the collar, it squeezes the tubes together. or the better ones may have a rubber ring under the collar that squishes out to tighten it.
 |
 NEW BLUE METALLIC SENSA CLOUD 9 Twist Retractable BALLPOINT PEN MSRP 2499 $2.99 Time Remaining: 2d 12h 45m Buy It Now for only: $3.99 |
 VINTAGE 1966 LADIES SEXY LEG PEN MADE IN CALIFORNIA TWIST TO RETRACT TOP $7.99 Time Remaining: 4d 6h 59m |
 Cross Metropolis fluted brass barrel twist Retractable Ballpoint Pen usa freeshp $19.99 Time Remaining: 7d 23h 28m Buy It Now for only: $19.99 |
 Sensa Cloud 9 Twist Retractable Ball Point Gel Pen Crimson Metallic 2 for 999 $9.99 Time Remaining: 14d 8h 7m Buy It Now for only: $9.99 |
 Sensa Cloud 9 Twist Retractable Ball Point Gel Pen Silver Metallic 2 for 999 $9.99 Time Remaining: 14d 8h 10m Buy It Now for only: $9.99 |
 Parker Lifestyle Mocha Twist Retractable Ballpoint Pen $9.99 Time Remaining: 18d 3h 28m Buy It Now for only: $9.99 |
 USS ESSEX LHD 2 PEN Retractable Twist Ballpoint $19.99 Time Remaining: 18d 9h 59m Buy It Now for only: $19.99 |