Fri Apr 1 2005

Squeezer problems

I've been using my Main Squeeze squeezer to dimple the flanges of the ribs. However, something got bound up inside. Basically The handle didn't want to close all the way anymore. Being an engineer, I had to see what was up. The mechanism inside is a toggle mechanism. But what's this?...this pivot bushing is bent. I wonder why that happened?

The bushing at the back seems OK.

Here you can see how the toggle mechanism works. Pretty clever design. It takes *way* less handle force to squeeze a rivet with this tool than with a typical Tatco squeezer.

I didn't like the fact that the design of these joints allows the mechanism to open up quite a bit of slop, though.

Looks like a similar amount of slop at this joint when you retract the plunger (i.e. open the handle).

...kinda hard to see here, but when the bushing siezed at it's outer surface, it actually gouged the side of the aluminum link.

If you know anything about toggle mechanisms, you know they can generate a tremendous amount of force when the links are nearly inline. The frame structure has to be quite strong to react all that force. Here, the cover itself is being used to react a portion of the load. The Screws which hold this cover on are countersunk screws, so when tight, this cover esentially becomes part of the structural frame.