Archive for the ‘Grab Bar’ Category

Secondary Grab Bar Mechanism

I am also working on a prototype grab bar (those bars mounted to the walls in handicap accessible bathrooms). This is an attachment to existing bars that will fold out out of the way. The secondary bar needs to lock as soon as any normal force is applied to it. I’ve found these shaft couplings on McMaster-Carr and thought they would be ideal.

Yesterday, after receiving the parts, I was a little disappointed in my choice. The parts fit together only at specific intervals. If the teeth didn’t line up perfectly, the two parts wouldn’t interlock. Well today Jowers had the idea to bevel the edges and it seemed to work. I turned them down on the lathe. I honestly expected the teeth to look like crap afterward. I expected a lot of knocking as the teeth passed the cutting tool. However they turned out 100% professional looking. I needed the mental win after yesterday.

Unbeveled and beveled teethUnbeveled and beveled teeth.

I also wound some springs to hold the interlocking pieces apart until a load is applied. I used a tool we have called the Universal Spring Tool. It worked pretty well. See the how-to video below.