ADJUSTABLE LEG LOCK FOR ALUMINUM SCAFFOLDING
THE ADJUSTABLE LEG LOCK IS A MECHANISM THAT LETS THE ADJUSTABLE LEG SLIDE IN AND OUT OF THE SCAFFOLDING FRAME. Aluminum scaffolding cannot have more than 12 inches of adjustability in its legs. For the adjustable leg to have a true 12 inches of adjustability the leg needs to have 13 inches of thread (will talk about this in another section). The adjustable leg lock is a mechanism that unlocks a split threaded nut allowing the adjustable leg to slide in and out freely. When you’ve reached your desired length you lock it by pushing the outer ring straight down. This will engage the threads of the split threaded nut into the threads of the adjustable leg.
If for some reason the ring will not slide down just slide the leg in or out just a little. What is happening is you’re trying to mesh a thread on top of another thread. So by moving the leg either in or out a little bit the thread will slide into the threads of the leg.
How it happens:
The leg lock mechanism consists of a split threaded nut and a knurled ring that when lifted and twisted up releases the split threaded nut which expands out releasing its threads from the threads of the aluminum leg. This then gives you the ability to slide the aluminum threaded leg in and out of the base frame. This gives you the ability to level your scaffolding on un-even surfaces or to help you get over objects. The adjustable legs are never to be used to gain height. Please refer to your instruction manual.
Damaged adjustable leg lock:
A picture is worth a 1000 words regarding this damaged adjustable leg lock. The adjustable leg lock is held in by a set screw. As you can see the set screw was missing from the adjustable leg lock mechanism. The customer secured the leg lock mechanism with a wire wrapped around the adjustable leg lock mechanism and over the horizontal rung.
The customer I can only assume tried to fix this in the field. What happened is he wound up holding the ring to the leg lock mechanism open. So the leg was not secured in the frame and could slide out if the scaffolding were rolled over a negative area. All the customer needed was a set screw and a screwdriver to fix the problem.
I would highly recommend when it comes to parts of the scaffolding like the adjustable leg lock mechanism, adjustable legs, short pin, long pin interlock clips and bushings that the customer carries these with them at all times. The adjustable leg mechanism in the other mentioned above parts are field replaceable. So read your safety manual, carrier spare parts and the tools to make the repairs in the field.
As we like to say at Upright Scaffolds North America, “If you need to get up, get upright with Upright Scaffolds North America.”