Wedge Tensile Grip Design - UTM Testing Machine

[fede280385]

TL;DR

Desing of wedge tensile grip

Hello to all.
I am new at PF. I am very happy to be here now that I know you.

I am at the middle of a UTM (universal tensile machine) design. My machine is going to be a simple testing machine in which I only intent to measure the ultimate tensile strenght. That been said, I want to be as clear as I can be.

Part of the design includes the fabrication of the wedge tensile grips (or tensile clamp body). I have selected one design and it is the one with moving body and stationary jaws (you can see the attached pictures).

I need to know to continue with the design what is tha part marked in red and what is it used for, because I can not understand it.

Thank you all.

Hope you reply soon

 

[Baluncore]

Welcome to PF.
Maybe it has something to do with the way the jaws are released so the test piece can be withdrawn after the test. You may also need to observe that the test piece is properly inserted for the full length of the jaws.

 

[jrmichler]

A search with search terms tensile test machine wedge grips found a lot of information on wedge grips. You can also get good background information by searching self locking wedge, noting how self locking wedges differ from non-self locking wedges. and considering how they apply to wedge grips.

 

[fede280385]

In the right figure, I believe one of the "holes" is a grease fitting and the other hole may be some kind of stop or end.

What I still can not figure out is the keyway in the left figure. What is it for?

Can you help me?

 

[Baluncore]

What I still can not figure out is the keyway in the left figure. What is it for?

It may be a slot for a flat taper used to separate the assembly. Take a look at the quill of a drill press that accepts a tapered drill shank or attachment.