Coil Couplers-Why and how do they operate

If you're talking an older post-war milk car, they are activated on a operating track by the shoe on the truck when you press the uncouple button.  This is strictly a conventional operation, the coil couplers were replaced by the magnetic couplers in the early 50's I believe.

The coil is an electromagnet. In the center of the coil is a metal pin and a spring.

The spring pushes the metal pin against the back of the knuckle, which has a notch to receive the pin, locking it closed.

When the electromagnet is energized, the pin is pulled back, releasing the knuckle.

A spring mounted by the knuckle's hinge pin pushes it open.

If the spring by the hinge is bad, the knuckle will only open if the train is moving, thereby pulling on the knuckle.

Each truck should have a sliding shoe that makes contact with extra rails that are mounted on the control track. As John wrote, post war trains are not controlled by TMCC. They predate it.
I guess that some folks convert their postwar to use TMCC for control.

Here's an exploded view of a coil coupler. 

Thanks Chris! A very Nice Resource! Will have to see about some of the paid articles and CDs.

You may also like to take advantage of the Lionel factory Service manual, which was been posted online as a free resource from Olsen's toy train parts.

Here is one of the pages on the coil coupler.

I recently converted all four of my PW switchers (2 623, 6250 and 624) to Teledyne couplers. VERY cool. I kept the rear controlled by the sliding shoe and therefore a UCS track, but connected the front coil to a whistle/horn relay so I can open that one anyplace on the track. It would only work with a coil coupler.

Roger

I have some that need fixing, where do we get the two springs and the rivet from?

Jeff Kane has them at ttender.com

Roger

Try www.ttender.com if the above link does not work without it.

I assume his car is the #3462 Operating Milk car.  In that case pressing the “Unload” button on the operating track controller to eject the milk cans will also open the couplers, which is usually not intended and requires backing up the train to re-couple the car to the cars on both ends of it.  Likewise the couplers on any post-war car equipped with coil couplers will open if the “Unload” button is pressed accidently when the car travels over the operating track section. 

HTH,

Bill 

Thanks for all the help.I am still learning and the different sources for information really are nice. I have replace the trucks with standard Lionel trucks to avoid the uncouple when unloading issue. But because of the new info I was able to remove one of the coils and use it on my 624 switcher that I am rebuilding now with bell sounds thanks to another great lead. You can image how much I am enjoying all of this, as my wife says,"you are possessed". Back to the Train Cave.

LOL when I clicked on the post, I thought you meant the coilcouplers.com website.

This will probably confuse the issue further, but it is possible to control that car with the Mini-Commander. As I recall, there are only two high current outputs, so you would have to pick two of coupler1, coupler2, or internal action.

As an aside, post war coil couplers are within a few tenths of an ohm of modern coil couplers and can be used with TMCC with the addition or a R2LC or one of the boards sold by Electric RR for this purpose. I used them on TMCC upgrade of a modern 1615 0-4-0 remake which came with plastic trucks and magnetic couplers.

Pete

I've also used the old PW coil couplers with an ERR board, they do indeed work fine.