Loose Handle on Beam Style Torque Wrench?

[superdansilverman]

I bought an old CDI beam torque wrench on fleabay, a 1002BIFI. It's a pretty unique torque wrench. It is only about 8" long and goes up to 100 inch-lb. But it has a 3/8" drive instead of the 1/4" drive you might expect for a wrench of this size and torque range. It also had a couple of unique "features" that I would like to tell you all about:

The first is, it's got a little doohickey that clamps onto the underside of the pointer. It looks just like the way a chip breaker clamps onto a plane iron. This doohickey contacts a tiny lever which appears to be under spring pressure, but only when the wrench is right around zero torque. I assumed this is to provide extra torque one way or another to make the low range more accurate. If anyone knows better, I'd love to hear about it.

The second is, there's some wobble or play in the handle. I would expect this on a larger beam torque wrench, where the "floating" handle is often pinned in the center to ensure that the beam bends in a predicable fashion. But this wrench has a ball handle, and it wobbles in all directions, instead of just along the axis of rotation of the wrench. I've never seen a ball handle torque wrench wobble like this, so I'm curious if anyone knows whether this is just another kind of floating handle, or if it indicates that the wrench is worn out and no longer accurate.

I am including some old pictures of this wrench, and tomorrow I will add better pictures of the cool flippy lever mechanism in action. Hopefully someone can explain to me exactly what it does!

 

[jallyn]

Looks interesting. I like it.

I assume the "doohicky" is to protect the tool during storage in a tool box, back of the truck, transportation, etc. It normally holds the pointer away from the scale so that doesn't get scratched up.

The ball handle is loose for a reason as you mentioned. There is a ball within the ball handle. Nothing is worn out. When you use the torque wrench hold the handle in such a way as to allow the center of the handle to contact the ball end within the handle.

 

[guy48065]

I've never seen that "doohickey" before but I'm sure it doesn't apply any force to the beam or indicator--this would negatively affect accuracy.

I'm wondering if you loosen the nut and swing the doohickey out if it might be a stop, peak indicator, or the like--which are common on beamers. For it to be a peak indicator it would need to move with nearly zero force so as not to affect the torque reading.

 

[bob15]

Are they memory fingers like this: http://www.srtorque.com/Downloads/PartsPrints/850191.pdf

or is the clicker that some beam models have that let you know you reached the correct torque? And yea some beam models have a clicker feature.....

 

[Fixnair]

That clicker thing can be set to your given torque spec and when you reach that point it will slip past the pointer allowing you to hear and feel that you have reached the proper torque.

As far as going out of calibration? Not likely. The only way a beam wrench can loose it's calibration is if someone heats the beam to the point that the molecular structure of the beam is changed. Even if the pointer beam gets bent, all you have to do is bend it back so it rests on zero again.

I have a 3/4" beam torque wrench which I trust. It's about 3 feet long. Only downside is when you are torquing something down to 250 ft pounds it's kinda hard to read the scale. You will need help to read the scale while you're pulling.