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How prototype coupler draft gear really works

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How prototype coupler draft gear really works
Posted by dknelson on Friday, June 29, 2018 10:00 AM

Miner is one of the oldest names in railroad supplies and they have recently posted this excellent video on how draft grear works (standard draft gear, not cushioned underframe).  

https://www.youtube.com/watch?v=1GxTVgvHD9A

the irony is that an earlier generation of couplers in HO, such as the old Varney "dummy" knuckle coupler, and the Kadees that were more complex to assemble than the #5, such as the #6, #7, #8, had more of this spring action built into them.  That is a train with those couplers would show the buff action but due to the low mass of our trains, it was more of a "slinky" kind of look.

Dave Nelson 

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Posted by SeeYou190 on Friday, June 29, 2018 10:29 AM

When I was in N scale, the Micro-Trains coupler, I think it was #1027, had a lot of this action built in.

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In HO sclae, the Kadee #4 was the most similar I think, but it was all metal and you had to peen a rivet to assemble it.

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-Kevin

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Happily modeling the STRATTON & GILLETTE RAILROAD located in a world of plausible nonsense set in August, 1954.

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Posted by doctorwayne on Saturday, June 30, 2018 4:58 PM

Kadee's first commercially viable coupler was the K-type, which was very similar to the #4, but used a straight wire extending downward from the knuckle.  This allowed automatic remotely-controlled mechanical uncoupling (no magnets involved)..  All of my first HO trains were equipped with them, and some of my current MoW equipment still uses them, minus the uncoupling pin.

Wayne

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Posted by SeeYou190 on Saturday, June 30, 2018 6:52 PM

When I swicthed to HO in the mid/late 1990s, the older guys in the club all swore the #4 was the best coupler ever made, and the #5 was cheap junk.

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I tired #4s and did not like them at all.

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I really prefer whisker couplers and #20 series!

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-Kevin

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Happily modeling the STRATTON & GILLETTE RAILROAD located in a world of plausible nonsense set in August, 1954.

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Posted by BNSF UP and others modeler on Saturday, June 30, 2018 8:05 PM

Can you still buy the ones shown in that picture? Also, how do they atoumatically uncouple without magnets? I have been looking for a way to do that that does not need magnets or a motor to pull a string.

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Posted by 7j43k on Saturday, June 30, 2018 8:08 PM

dknelson

...and the Kadees that were more complex to assemble than the #5, such as the #6, #7, #8, had more of this spring action built into them.   

 

I know the Kadee MK-8 had no spring action along the length of the car.  They had a sort of hairpin centering spring, the draft gear "box" was two part and round, and a 2/56 mounting screw went through the middle.

PERHAPS the K-8 had a different design, but it's hard to believe.  I'm not even sure there were K-6 through K-8.  I think the K-6, K-7, and K-8 were all the same design, but with different lengths of coupler shank.

Thus, I don't think the K-6, K-7, and K-8 had a "spring action".  Note that I'm not 100% on this, but it is what I recall.

 

The Kadee "K" line (K-4, etc.) was a mechanical coupler with a vertical pin descending from the knuckle.  Wayne has a photo (above) of a K-4.  I do recall that at least some of the Ulrich cars used the K-4.  For the Ulrich, the coupler box was a part of the car body casting.  There was a stamped sheet metal cover that held the coupler in place.

Next, there was the Kadee "MK" line.  It was a magnetic coupler that looked pretty much like the present "full-size" Kadees.  I THINK there was an MK-4 (see above).

Then there was the Kadee "MKD" line.  It was a delayed-action magnetic coupler.  It used an assymetrical coupler spring.  I think that's maybe when the 6-7-8 mounting style disappeared, because the spring was symmetrical, and wouldn't then do the delay.

 

I surely don't know why Kadee doesn't have an historical page on their website concerning their history.  I went over to Hoseeker, and they didn't have anything about the above.

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Posted by 7j43k on Saturday, June 30, 2018 8:15 PM

BNSF UP and others modeler

Can you still buy the ones shown in that picture?

Yes, from collectors.  Not from Kadee.

Also, how do they atoumatically uncouple without magnets? I have been looking for a woy to do that that does not need magnets or a motor to pull a string.

 

 
The two pins of adjoining couplers are spread apart.  This opens the knuckles.  
 
Kadee had two kinds of uncouplers.  
 
One was a long diamond shape that you had to raise up from between the rails so that the pins could be engaged.
 
The other was a permanently raised style that was designed for stub sidings.  If you shoved a coupler pair up to the middle of the uncoupler, you could then back your train out and leave the car(s) on the far side of the ramp.  To pick them up, you shoved the picking-up coupler past the uncoupler, then coupled onto the car(s) to be picked up.  The ramp was designed such that you could then pull the cars back out, and they remained coupled.
 
 
Ed

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