Back plate drawing legend

Discussion in '400-Day & Atmos' started by Harry Hopkins, Aug 30, 2018.

  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.
  1. Harry Hopkins

    Harry Hopkins Registered User
    NAWCC Member

    Nov 16, 2011
    543
    37
    28
    Retired Instrument Technician
    Mason, IL
    Country Flag:
    Region Flag:
    I was recently using the Repair Guide (10th) to identify a movement and saw a symbol I had not noticed before. I know that solid black circles are threaded and open circles are normally pivot holes but what does a circle with a black dot in it represent? I cannot find a description of this symbol in the book.

    Example shown for the suspension spring guard holes in picture below.
    ee24da43-4bbd-4798-ba18-4ff7fb5ab0a2.jpg
     
  2. etmb61

    etmb61 Registered User
    NAWCC Member

    Oct 25, 2010
    2,204
    91
    48
    Retired Avionics Technician
    Mascoutah, IL
    Country Flag:
    Region Flag:
    Harry,

    Those represent the little posts the "Safety Bridge" mounts onto. See the diagram on page 12.

    Eric

    SB_posts.jpg
     
  3. Harry Hopkins

    Harry Hopkins Registered User
    NAWCC Member

    Nov 16, 2011
    543
    37
    28
    Retired Instrument Technician
    Mason, IL
    Country Flag:
    Region Flag:
    Thanks Eric, I have not seen a Safety Bridge guard until your picture. So I am guessing the posts must be riveted or staked into the back plate since the Repair Guide drawing does not show threaded holes.

    I only noticed the symbol while looking to identify a different movement but curiosity got the best of me. Thanks again!
     
  4. etmb61

    etmb61 Registered User
    NAWCC Member

    Oct 25, 2010
    2,204
    91
    48
    Retired Avionics Technician
    Mascoutah, IL
    Country Flag:
    Region Flag:
    #4 etmb61, Aug 30, 2018
    Last edited: Aug 30, 2018
    The posts just thread in. They probably could have drawn black dots for the holes, but most of the time I've found when the bridge is missing the posts remain. There's no real need to ever take them out. Terwilliger probably noticed the same thing.

    Eric

    posts.jpg
     
  5. etmb61

    etmb61 Registered User
    NAWCC Member

    Oct 25, 2010
    2,204
    91
    48
    Retired Avionics Technician
    Mascoutah, IL
    Country Flag:
    Region Flag:
    In a related story...

    I just picked up an original copy of those instructions shown on page 12 of the RG.

    1.jpg

    Eric
     

Share This Page