Universal joint/ball bearing controlled rotating arm for a furniture fitting

[carlbrorson]

Universal joint/ball bearing... controlled rotating arm for a furniture fitting

Hello forum,
I need your help on a furniture project we are developing in the office.
its basically a floor standing lamp which needs to have a user regulated rotating arm. We are right now looking at different options for testing out on prototype but thuoght to check with the experts before we go out on a shopping spree..

Please see attached detail of proposed design. The light housed would be an LED T8 tube and the movement would be regulated by user, tilting it a couple of degrees each way (not looking for a 90degree tilt, more like 35degree..) The part where we need your input is for the arm indicated as bearing/regulated rotating arm in the drawing. please have a look and let me know if it all makes sense to you.

Thank you
C

 

[Danger]

Welcome to PF, Carlbrorson.
Nice diagrams. Your question is a bit unclear, though. Since the section indicated shows no actuators, might I assume that your problem is in regard to what mechanism should be used?
If so, my first thought would be a triaxial cable system similar to the way a remote-controlled car mirror is set up.

 

[carlbrorson]

Hello Danger, thanks for having a look at it. yes, sorry not beeing so clear about it, I am swedish after all! it is abuot the mechanics, yes, and how this possibly could be solved. just googled the triaxial cable system and kind of get the principle, but it seems complicated for this application no? can't i just get away using a universal joint of some sort you recon? thanks c

 

[Danger]

The ball/socket setup that you show is a universal joint, and should work just fine. The question still comes down to 'what makes it move?' That's why I suggested the cables, which would be controlled by a joystick and take up minimal space within the housing.

 

[carlbrorson]

Oh ok i see now. well the user makes the light move by his/her force, your idea with the cables makes sense now though, and i will look further into it. perhaps i can ask - could you perhaps recommend a universal joint for us to buy? thanks c

 

[Danger]

I'm afraid that I can't; I don't have any experience with such things. I've always just scavenged stuff like that from crap lying around in my basement.
The one labelled 'indicative image' in your link seems fine, so maybe track down the manufacturer and see what they have to offer. Fred Garvin, Astronuc, Brewnog and a handfull of others here on PF are very good at recommending sources for mechanical equipment. Perhaps one of them can help you more.

 

[carlbrorson]

brilliant thanks
c