Who makes these? Or what are they called?

[steve66]

I don't even know the proper term for these. Everyone else keeps calling it a "rotary switch", but I'll refer to it as a "rotary device" because it doesn't have any switches in it. Just some contacts that always stay closed as the unit rotates.

Let me start from the begining: We've got a jig that holds a workpiece. The jig can turn the workpiece around so people can work on it. (It turns around a horiz. axis - kind of like a lathe would turn a piece of wood.) There are some safety switches that make sure safety pins are inserted to hold the workpiece. These switches spin with the workpiece so I need to specify one of these "rotary devices" to connnect the wiring from these switches to the control panel.

Does anyone know what this would be called, or who makes them?

 

[winnie]

They are called 'slip rings' or 'slip ring assemblies'. I've never had to buy, specify, or use them, so I don't know where to point you beyond a name.

-Jon

 

[Jraef]

Wampfler, which apparently is now Conductix.

http://www.conductix.us/productpage.cfm?Ids=460

 

[Cow]

We call them slip rings. I've only seen them used on irrigation pivots.

 

[sii]

Conductix has come a long way from when they used to be Insul8. THey now make very durable slip rings. We abuse the heck out of the ones we have and they stand up fairly well. They have a data sheet you can download to spec out exactly what you want.

McMaster Carr offers a couple (comparatively) inexpensive models but those cannot be customized. With Conductix you can pretty much design exactly what you want and they have great tech support.

 

[dbuckley]

Another manufacturer is Mercotac.

 

[kwired]

We call them slip rings. I've only seen them used on irrigation pivots.

They are also common on grain stirring systems.

 

[steve66]

Thanks. I've learned a new term.

I've also found slip rings made by Moog, and Gleason.

 

[Jraef]

Another manufacturer is Mercotac.

Are they still mercury based? I had to remove some from a machine once because of that. People are very nervous about having mercury in anything now.

 

[dbuckley]

Are they still mercury based?

I have no idea.

However, I suspect not; if there were mercury in there then there would be mounting instructions limiting the angles one could be installed at, and last I saw one (which was a little while ago) there were no such limitations.

 

[a.bisnath]

seen them in slurry mixing devices ,wound rotor motors,cable reels for cranes and portal devices,siemens also carry them

 

[Jraef]

I have no idea.

However, I suspect not; if there were mercury in there then there would be mounting instructions limiting the angles one could be installed at, and last I saw one (which was a little while ago) there were no such limitations.

Methinks they doth still have mercury in them. From their FAQs

Why are Mercotac rotating connectors superior to slip rings?
Mercotac rotating connectors use a unique design principle unlike the sliding, brush contact of a slip ring. The connection is made through a pool of liquid metal molecularly bonded to the contact, which provides a low resistance, stable connection. When there is rotation the fluid maintains the electrical connection between the contacts without any wear.

A little marketing spin there don't you think? They seem to be working hard at avoiding the word mercury, but the only other "liquid metal" is bromine, and that is way to expensive and toxic compared to Hg.

Another FAQ does say there are restrictions on mounting positions too.

 

[dbuckley]

A little marketing spin there don't you think?

I do, and I am stunned.

I need to write a couple of emails