What's this thingy called? (On a wood folding bed camera)

[Will Frostmill]

I'm stumped on how to figure this thing out. It's a doohicky found on the end of a wooden folding bed camera that keeps the back assembly from falling off the rails. But! I don't know what it's called, and I don't know how to work it! The doohicky seems to have a post that extends into the bed, and is partially visible in the leftmost hole

Image 1: the doohicky
https://www.largeformatphotography.info/forum/attachment.php?attachmentid=187680&d=1550084688

Image 2: the post that extends into the leftmost hole on the end.
https://www.largeformatphotography.info/forum/attachment.php?attachmentid=187679&d=1550084673

Some background: I'm restoring a Conley 5x7 that I bought from another forum member a few years ago. Right now I'm in the "patch the bellows & get the geared bed tracks clean and functional" stage.

Will

[Doremus Scudder]

How about "stop"? As in, the stop that keeps the back from coming off the rails. It is often a brass cylinder held in place by a screw.

Best,

Doremus

[pepeguitarra]

Stop/Lock, to prevent the camera from moving into the abyss when the rail extension is not there.

[Tin Can]

and when the extension tailboard alignment post is inserted it will either raise the stop out of the way or rotate it out of the way automatically

poke it with a stick

[Will Frostmill]

A ha! Very cool!
Especially the "poke it with a stick" method! Excellent!

Thank you everyone, for your replies, and for replying quickly!
Will
p.s.
I just poked it. This one rotates counterclockwise, and there is a very stiff spring behind it. The flathead screw that holds the stop in place is pretty insubstantial, and immediately popped out of the wood. A very clever design.

[David Lobato]

I have an 8x10 Conley that I'm fond of because it's simple and relatively light to carry. Good luck with your 5x7.

[Alan Gales]

Stop or lock sounds reasonable but I actually prefer "doohicky". :)