The sliding key leaves a bit to be desired
[Ben Conrad] received an interesting tool as a gift that was supposed to be a better mousetrap. It was an adjustable wrench (made by the Crescent company, same) that didn't have a small adjustment wheel like a traditional wrench. Instead, there was a slider the full length of the handle. The idea is that you would push the slide to clamp the jaws of the wrench against the bolt or nut, and it would be quick and easy compared to a conventional wrench. As [Ben] notes, however, it doesn't work very well. Most of us would have just thrown it in the back of the toolbox or given it back. [Ben] tore his to find out what was wrong.
A typical adjustable wrench has four parts. This one has 19 pieces and looks like a conventional wrench with an extra slide and screw running the length of the handle. [Ben] found the parts to be poorly made, but that wasn't the main issue.
While the poor machining caused the mechanism to skip and jam, he also found that even with perfect machining, the design wasn't very good. The wrench jaws move approximately one inch and the slide moves approximately 2.5 inches. So that should provide a mechanical advantage, right? It turns out that the screw is inefficient and absorbs any potential strength gains.
At first glance, the adjustable wrench seems like a good idea to think "outside the box". But the execution seems flawed. You have to wonder, though, how many basic tools could be improved if we stopped and thought without a lifetime of preconceptions.
We've already pointed out that if you build a better mousetrap, it better be better. Again, why adjust a wrench when you can make one the right size?
[Ben Conrad] received an interesting tool as a gift that was supposed to be a better mousetrap. It was an adjustable wrench (made by the Crescent company, same) that didn't have a small adjustment wheel like a traditional wrench. Instead, there was a slider the full length of the handle. The idea is that you would push the slide to clamp the jaws of the wrench against the bolt or nut, and it would be quick and easy compared to a conventional wrench. As [Ben] notes, however, it doesn't work very well. Most of us would have just thrown it in the back of the toolbox or given it back. [Ben] tore his to find out what was wrong.
A typical adjustable wrench has four parts. This one has 19 pieces and looks like a conventional wrench with an extra slide and screw running the length of the handle. [Ben] found the parts to be poorly made, but that wasn't the main issue.
While the poor machining caused the mechanism to skip and jam, he also found that even with perfect machining, the design wasn't very good. The wrench jaws move approximately one inch and the slide moves approximately 2.5 inches. So that should provide a mechanical advantage, right? It turns out that the screw is inefficient and absorbs any potential strength gains.
At first glance, the adjustable wrench seems like a good idea to think "outside the box". But the execution seems flawed. You have to wonder, though, how many basic tools could be improved if we stopped and thought without a lifetime of preconceptions.
We've already pointed out that if you build a better mousetrap, it better be better. Again, why adjust a wrench when you can make one the right size?
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