Date:         Sun, 8 Dec 1996 20:50:00 -0500

Reply-To:     MARTIN TAI <martin.tai@w....>

Sender:       The Subminiature Photography Mailing List

              <SUBMINI-L@LISTSERV.AOL.COM>

From:         MARTIN TAI <martin.tai@W....>

Organization: Westonia Computer Systems of Canada

Subject:      Minox shutter Action diagram Rev 2.

  Rev 1 of Minox Shutter diagram still has some error (about

at what stage the shtter is tensioned etc.

  At weekend, I spend some time looking for photo of Minox

shutter blades, and checked step by step with my Minox IIIs, as

to when the shutter is tensioned, when the release button become

deactivated or activated etc, and come up with a revision 2 )

  For most Minox users, this is boring stuff. But I have to

keep the record as free from error as possible, as a part

of Minoxology :)

  And beside, such detailed  diagram  may not be easy to find

from elsewhere,  unless one have acess to  Minox GmbH engineering

department ( and photo them with Minox :)

  My version, though base on Heckmann's schematic, is a side

view which shows more clearly how the blades open or shut the

lens , and also documenting when the shutter button is deactivated

when it is activated etc.

                 Minox A/B Shutter Action Diagram  (Rev 2 )

     Minox A/B shutter conists of two blades one at front (B1)

one at back (B2)

     B2 has an opening at the right hand side, a  circle 'o' mark

at left  ( view from front of camera )

                      LENS

                      ( )

                               opening

                   _____________________________________  rivet hook

                  |            ________      -----------)

         B2       |    o      (       )      |

      ____________|           (_______)      |

     |_______________________________________|

     spring hook

  Shutter blade 1 has an opening at left side.

      spring hook     opening

      ________________________________________

     |____________      ____                 |

                  |    |    |                |

                  |    |____|                |___________  rivet hook

         B1       |______________________________________)

                      [      ] lens window

       The  opening on B2 is slightly larger then the opening

of B1 ( imo, for tolerance reason ).

       When the camera is opened, B1 is overlad in front of B2.

>From the lens window one can see through the opening of B1 and

see  the circle  'o' of B2.

       At this moment,   B2 shuts the lens.

      Schematically,  a shutter blade can be represented by

          [||o||          ]

       |||| indicates steel, the empty space represents opening

on the blade.

    And the Minox shutter can be represented by the

following diagram,

                    ( )         lens

      spring

      xxxxxxxxxxxx[||o||     ||]  B2

      xxxxxxxxxxxx[|   ||||||||]  B1

                   [   ] lens window

     That is what you normally see, when you pull open the Minox

     You see the circle 'o' on the second blade throught the

 opening of first blade

     If you use a mangifying glass, you may be able to see

the edge of the opening of first blade.

    The following schematics depict the shutter operating sequence.

   1) CAMERA CLOSED

      Shutter springs in tensioned state

      Shutter release disabled

                    ( )         lens           shut

      spring

      xxxxxxxxxxxx[||o||     ||]  B2           shut

      xxxxxxxxxxxx[|   ||||||||]  B1           open

                   [   ] lens window           show  circle o

   2) Open Minox

      Unlock shutter release

                    ( )         lens

      spring

      xxxxxxxxxxxx[||o||     ||]  B2

      xxxxxxxxxxxx[|   ||||||||]  B1

                   [   ] lens window

      Carefull ! Partially open Minox even 3-4 mm will unlock shutter,

  if pressing shutter button, the shutter will

  go off prematurely !

3) Press button -->Shutter released

   Blade B2 spring released, B2 moves left to open lens

   Lens fully open, as B1 already open.

                    ( )         lens    FULL OPEN

      spring

      xxxxxxx[||o||     ||]  B2          open

      xxxxxxxxxxxx[|   ||||||||]  B1     open

                   [   ] lens window

        Xsync trigger.

        Film exposed.

4)  DELAY UNTIL TIME UP

      The  delay mechanism start count down, according to

set time from the speed dial. ( 1/2 to  1/1000)

                    ( )         lens     FULL OPEN

      spring

      xxxxxxx[||o||     ||]  B2          open

      xxxxxxxxxxxx[|   ||||||||]  B1     open

                   [   ] lens window

5) Shutter closed

   Time up

   Release blade B1 spring, B1 moves sideway to cover lens

   B2 remain open to lens.

                    ( )         lens     SHUT

      spring

      xxxxxxx[||o||     ||]  B2          open

      xxxxxxx[|   ||||||||]  B1          shut

                   [   ] lens window     see blade 2

6)  CLOSE CAMERA

  * Push  blade B1 and B2 back to original position

  * Shutter spring tensioned ( zzzzzzzzzzzzzzzzzzz )

  * Shutter button deactivated.

                    ( )         lens           shut

      spring

      xxxxxxxxxxxx[||o||     ||]  B2           shut

      xxxxxxxxxxxx[|   ||||||||]  B1           open

                   [   ] lens window           show  circle o

Martin Tai

 Revision  Dec 8, 1996