Have a look at the photos towards the bottom of the thread in the first link below. The clamps were from the rim tool type shown in the advertisement, and were given to me without the rest of the tool. They could easily be made. The photos show the rim both in the collapsed position and in the expanded position as it would be with the tire installed. The two clamps pivot in the body of the tool.
Looking at the photo of the tool fitted to the rim in the expanded position, the initial movement of the rim tool handle lifts the left hand side of the rim joint vertically clear of the staple for the locking cotter on the RHS of the rim joint, then continuing movement of the handle drags the LHS of the rim joint below the RHS, thus collapsing the rim. If the rim clamps are not disturbed, moving the handle back to the original position after the tire has been fitted will return the rim to the expanded position with no further adjustments needed.
https://vccachat.org/ubbthreads.php...e_Mount_tire_on_28_disc_wheel#Post125062The tool in the form shown in the above link was a trial to get dimensions correct. The final form is shown in the first photo here:
https://vccachat.org/ubbthreads.php...ranco/Search/true/Re_Rim_Tool#Post186166Frank
