Could someone please explain to me the difference between an open and closed collar

For bust quarters, not much functional difference between the two from what I can tell. Both collars added reeded edges as the coins were struck.
The “closed” or “close” collar probably had a different look or mechanism due to the change in presses between 1828 and 1831.

**I'm wondering if the reeding could have been applied while stamping out the planchets. Cutting in the reeds while punching through the silver sheets. Just a thought but seems plausible. Dave

The reeding is part of the collar and is applied to the planchet when the coin is struck.

@Bustquarterhound said:

@scubafuel said:
For bust quarters, not much functional difference between the two from what I can tell. Both collars added reeded edges as the coins were struck.
The “closed” or “close” collar probably had a different look or mechanism due to the change in presses between 1828 and 1831.

I know this might sound crazy but,having never seen a die (collar) for appling the reeded edges . And never seen a coin with any evidence of a broken collar. Knowing the reading is to consistent to have been applied with a castaing machine. I'm wondering if the reeding could have been applied while stamping out the planchets. Cutting in the reeds while punching through the silver sheets. Just a thought but seems plausible. Dave

Here is evidence of a broken collar in the Bust Dime Variety Identification Guide that points to a close collar setup instead of reeding applied otherwise:

-Off center coins always have no reeding (disproves shearing), as opposed to Castaing-applied edge lettering that is always apparent on Capped Bust half dollars.
-Reeding on early coinage is nearly always unevenly pressed i.e. one side stronger than opposite side. (disproves Castaing and shearing)