The coupler action starts at the small hole shown in the pedal square:
The action then travels through the coupler roller board and up to a set of back falls.
The common pivot point of the back falls is mounted to a rail that can be raised or lowered thus
raising and lowering the tail end of the back falls. The front end of the back falls doesn't
move during coupler engagement and disengagement.
Here's a photo of the coupler rail slots being cut. I cut both the top and bottom halves
at the same time:
Then I cut a groove in each half to house the axle for the back falls:
Here's the coupler rail assembled with the back falls:
Here's the end of the rail that will be raised and lowered by the hitch down pedal:
Here are the felted holes in the manual base board through which the coupler sticklers act:
Here are the sticklers installed:
Here's the tail end of the CC manual key when the coupler is engaged:
Here's the same with the coupler disengaged:
Click here (1.6MB) for a movie showing the CCC pedal key played three times
with the coupler disengaged and then three times with the coupler engaged.
Here's the hitch down pedal with a universal joint at the tail end:
This is the linkage to which the hitch down pedal is connected:
Click here (1.3MB) for a movie showing the hitch down engaged and
disengaged (sorry I don't know how to rotate the video).
Click here (1.7MB) for a movie showing the coupler rail
with back falls engaged and disengaged.
And finally here are some photos of the complete assembly: