Threaded Connections

[JKropetz]

Greetings! I have a question that maybe you can answer. I will try the best to explain below.

I have a hub with through holes in a circular pattern located on flat surfaces that are milled. There is a connector bar that has tapped holes that are placed at a 4 degree pitch to the top face.

Can someone tell me the benefits of a threaded hole that is at a 4 degree pitch with a thru hole that is straight through? I feel this is causing major issues in assembly and other engineers feel the same but one engineer will not say why this is supposed to be this way. I may need to upload a "SAMPLE" print for you to see what Im talking about.


Thanks!

Justin

 

[JohnRBaker]

Yes, please do so (upload a print).

John R. Baker, P.E.
Product 'Evangelist'
Product Engineering Software
Siemens PLM Software Inc.
Industry Sector
Cypress, CA
Siemens PLM:
UG/NX Museum:

To an Engineer, the glass is twice as big as it needs to be.

 

[dhengr]

Do you mean that the axis of the threaded hole in the clamp/connector bar is 4̊ out of/away from perpendicular to the milled surfaces on the hub? Could this be an attempt to provide a bolt locking means, when the bolt if fully tightened and the connector bar is drawn tight. This will tend to bend the bolt a bit and deform the threads too. Maybe locking the bolt in place.

 

[Jboggs]

I don't like it. There should be a very good explanation for it. For all I can see, all it does is create undue stress on the screw, which would lead to premature failure. If a self-locking thread is desired there are many better ways to do it. Frankly it sounds like a screw up, either in design or in fabrication, to me.

 

[JKropetz]

Thank you gents for all your responses, I hope you can see the attached file.

 

[Tmoose]

Hi Justin,

got a 404 error on the pdf.

Is the "connector bar" circular too?

Kind of like a belleville washer perhaps?

 

[JKropetz]

The connector bar is square.

 

[chicopee]

You have to upload the file Pitched and same problem with PDF, 404 error.

 

[Tmoose]

Hi Justin,

I pictured a "nut plate" square/rectangular in cross section, but curving around to include several of the threaded holes, like a big washer, possibly cut into a few "C" sections.

Upon tightening such a thing with skewed holes the action >>might<< be similar to a belleville washer but at the poor bolts' expense and health.

http://upload.wikimedia.org/wikipedia/commons/7/77/Belleville_washer.jpg