[ Ref. author's earlier article in 201023 MMDigest.  -- Robbie

Noble Mignonite Elves and any others having interest, our present
subject continues and. blessedly, now concludes. This being so esoteric
a matter, meaning that about one or two out of some few tens might have
actual interest, I thought I'd make all clearer to such loyal stalwarts
by working up a part-sketch of the valve block type of interest, as
I found these within very early Mignon instruments long ago.

Inspect my drawing and "...all will be revealed..." Poirot-style, where
two valves of the novel Mignonesque pedaling effect are to be seen, as
[are] the suspects surely responsible for it: a lock and exhausting one
at left, and a canceling one right-wise, which operates also the small
exhaust pallet riding atop the pedal pneumatic proper.

Actually, in considering unsuspectingly now further on the rightmost
one, it does operate essentially as the Welte-Mignon (Licensee) pedal
valve, but excepting for one thing: the atmosphere intake is separated
from the underside of the lock pouch and carrier disk by an interposed,
pierced septum.

The fit between the wire and the hole through which it travels,
necessarily being close and there left as un-threaded so as to prevent
leakage. This, then, allowing vacuum to be introduced by the cancel
valve below the lock pouch, and thus neutralizing it's holding force
and directly after, pulling it down with considerable energy.

It might be recalled beneficially, that in the case of the Licensee
system, the lock pouchs holding bleed-supply is compromised by opening
of the tracker bar cancel duct. So, as a result, it simply drops the
vacuum level therein to neutral, the valve then accelerating downward
to full closure, being not pulled home by other than gravity and
finally, the hole it is covering when gotten near -- these three
forces.

Interposed between the lock valves own vacuum, serving to hold its
lock-pouch open, is a bleed of about drill size number sixty. It is
there emplaced so that the action of the lock and cancel valves will
prove even quicker than without, time and timing here being everything.
(Well, everywhere it is sovereign, actually.)

Adding to this rapidity of action is the cancel valves smaller set-
motion, this being of about 0.020" only. The work required of the
cancel valve is very little, as compared to the exhausting lock valve,
which wants to be on the order of 0.035-40" motion. The relief pallet
it operates remotely is quite small, and so displaces little atmosphere
in its operation.

Another factor aiding in the required rapidity of motion is that, with
exception of the regulated stack and valve supply, all mechanism is
operated at pump vacuum level, there being no interceding regulator as
with the W-M (Licensee) design.

The dotted-square surrounding the view is 5 inches square exactly; all
of the drawing's dimensions, representative precisely of those of the
originals.

As usual, for any I am happy to answer questions promptly, even if
coming solely from private messages. (Which now does seem the new-norm,
strangely.)

Jim Miller
Las Vegas, Nevada

 [ Early Mignon Pedal Lock & Cancel Detail View w. Dual-Speed Bleed Felt
 [ https://www.mmdigest.com/Attachments/20/10/30/201030_184805_MignonEarlyPedalLock&Cancel.png