A serious challenge

[algale]

I'd get a new wife.

That really would be costly!

Better still! That's means you will only be able to afford to build a one drawer jewelry box for her.

[Ed in Tampa]

I think the first hurdle is to figure how to lock the 27 th drawer if any of the non magical drawers are opened. After that it should be easy to reverse logic so the correct 7 must be opened.

I'm think a spring loaded pin the length of the 27 drawers and pins the 27 th drawer closed. Then a set of spring loaded latches that lock the bar should a non magic drawer is opened.

Perhaps a second rod that unlocks the 27 th drawer if the right 7 drawers are out releasing their latch with the last door releasing both latches.

[ERLover]

masonsailor2, take this tongue in cheek, it is a challenge and I am sure you are up to it and will be perfect!!! Many of these things were designed during the Victorian Age, so the Queen/Princess personal things/correspondences where hidden from her maiden servants that where spy's to the King/Prince. So what does Mrs masonsailor2 need to hide?????

[Ed in Tampa]

Think of it this way
To open one slide would have this combination where 1 is a release latch only if the drawer is open this slide would be under Constant Spring pressure to move slide out 27th drawer.. If any of the o drawers are opened they would lock the slide.
00000001000000010000011111
And the second slide would have this combination where any open drawer in a 1 position would lock the slide. But in closed position the slide is free to move and the last o releasing the spring to drive the slide out of the 27th drawer.
1111111101111111101111110000

[Ed in Tampa]

Even simpler
Make each drawer have an open close latch. Perhaps a strict of wood with keyholes. Min the open position the big opening would be on the bar in locked position the narrow part would hold the bar from moving.

Then set up the combination
llllllllollllllllllolllllllolllloolllool.
I means open drawer locks slide holding the 27 th drawer closed. O means the slide is released.

Basic amounts to mounting key hole strip to drawer where for l drawers the slot in on the big hole Iif the drawer is pulled out it locks the slide. On the 7 magic drawers the keyhole strip would be turned so
that the closed drawer puts the narrow locking the slide. Pulling the drawer out moves the strip to the large hole releasing the slid.

Spring load the rod to relapse the 27 th drawer when the others are in right position.

[Ed in Tampa]

"Better yet use a magnetic latch and give the magnet to you wife that only you and her knows where to put magnet on case to open the 27th drawer.

[ERLover]

masonsailor2, I forgot to mention after the Queen/Princess had it build only she and the builder new the secrets to opening the secret drawers/cabinets, and he suddenly was no where to be found!!!!!!!!!!!!!!LOL

[BuckeyeDennis]

What's the drawer configuration? Three rows of nine drawers each, in a regular grid?

[JPG]

Even simpler
Make each drawer have an open close latch. Perhaps a strict of wood with keyholes. Min the open position the big opening would be on the bar in locked position the narrow part would hold the bar from moving.

Then set up the combination
llllllllollllllllllolllllllolllloolllool.
I means open drawer locks slide holding the 27 th drawer closed. O means the slide is released.

Basic amounts to mounting key hole strip to drawer where for l drawers the slot in on the big hole Iif the drawer is pulled out it locks the slide. On the 7 magic drawers the keyhole strip would be turned so
that the closed drawer puts the narrow locking the slide. Pulling the drawer out moves the strip to the large hole releasing the slid.

Spring load the rod to relapse the 27 th drawer when the others are in right position.

The 'binary' stuff is the simple part.

The trick is to translate that into wooden parts.

Consider a vertical rail.

Notches on both the front and rear edges corresponding each of the 26 drawer locations(the 27th will be a different scene).

The notches on the rear are entered when a 'non 7' drawer is opened.

The notches on the front are vacated when each '7 drawer' is opened.

Thus the front notches perform the +and function of the '7 drawer', and the
rear notches perform the -or function of the other 19('non 7 drawer').

Any 'non 7' drawer open prevents the rail from moving vertically

Any missing '7 drawer' open also prevents the vertical bar from vertical movement.

A spring can move the rail vertically when all the notches are 'unoccupied'.

That vertical motion unlocks the 27th drawer.

The '7 drawer' have a pin that vacates the corresponding notch in the front rail.

The 'non 7 drawers' move a lever out of the corresponding rear notch when closed.

Missing is the details of how closing a '7 drawer' moves the rail back to the lock position as well as closing the 27th drawer. Some 'inclined' planes needed there.

notches, levers and pins lock and a slot unlocks.

[ChrisNeilan]

Look at a good office file cabinet. The good ones only allow one draw to open at a time. Mechanical stops on the draws. It keeps them from falling forward if someone were to open to many draws at once.