Dinghams Part3
Entry posted by Jon Fitness
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Hook and latches.
To match the hook and loop, on the other end of vehicles there is a hook and latch.
The latch is to provide a delayed coupling function. When the loop is lifted up by a magnet to uncouple, the latch is also flipped up at the same time but immediately drops again. When the loop drops after uncoupling, it will drop down on the latch rather than the hook so that vehicles can be propelled and left in a siding without having to uncouple again. To re-couple just draw away and return and the vehicles will re-couple.
The hook is prepared in almost the same way as before but is then fitted with one of two latch types. They both perform the same function and operate the same way but are assembled differently.
Note also, it is possible to vary where the hook sits in relation to the bufferheads on the vehicle by soldering the pocket further down the hook. This is useful if the vehicle you are fitting it to does not have adjustable buffer lengths and your layout has sharp curves.
Type 1 is less obtrusive and its operation is slightly more reliable, but type 2 is probably easier to assemble and fit.
My personal preference is for type 2 so I’ll start with that one.
Type 2 latches.
If fitting a type 2 latch, take off the little half etched pip from the top of the hook. This for type 1 latches and can cause false coupling with the loops if left on.
Clean up the latch with a scratchbrush and clear out the pivot holes with a 0.8mm drill waggled about (0.9mm leaves to holes a little to big IMHO)
The bending up process is similar to the loop except for the dropper which for some reason is on the other side of the etch and is just a simple bend down!
Bend the dropper down as close to the pivot tabs as possible (pic28) then bend up the pivot tabs, the side with the dropper at 90Ëš and the other at about 45Ëš.(Pic29)
Check the slot hasn’t closed up and offer up the latch to the pivot pin. As in pic 21, use pliers to close up the pivot tabs on the pin and check for alignment.
The latch should flip up and down freely. Note that the latch over hangs the end of the hook so that the coupling loop can lift it during coupling.
The little tab on the bottom of the hook should now be bent at 90Ëš towards the dropper and the dropper set so that the latch rises to almost vertical. Note that the tab is half etched and is on the other side to the dropper so extra care must be taken when bending to make sure that the tab comes out far enough for the dropper to catch. If the tab simply won’t catch the dropper, solder a short length of brass wire in it’s place.
Type 1 latch.
For type 1 latches, prepare the hook as previously shown but leave the little half etched pip on the top of the hook. This forms the limiter for the lifting action of the latch.
The type 1 latch is a simple loop that does the same job as the type 2 latch.
Clean the latch with a scratch brush and clear the holes with a 0.8mm drill. With this type of latch it is even more important not to introduce too much “slop” as the latch can miss the hook when dropping and this will stop the coupling from functioning correctly.
The loop has half etched marks on it to aid bending and should be bent over a piece of the etched strip provided in the kit for this purpose. It can then be opened gently and fitted over the pivot pin. At this stage the latch will drop over the hook too far as the end of the latch needs “filling in” so that it stands proud of the hook
This can either be done by carefully filling with solder or soldering a short length of the etched strip provided in the kit for this purpose
Once you are happy with the coupling, blacken it in the dip of your choice and it’s ready to fit.
The final 2 pics show a hook with a type 2 latch fitted to a bogie bolster wagon. This has been towed round a 4ft6inch radius curve (just!)
More soon if anyones interested 
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