Printed from the blog of Lori Greene, AHC/CDC, CCPR, FDAI
Email:, Blog: or

Jul 02 2017

Mysterious Hardware

Category: HistoricalLori @ 11:40 pm Comments (9)

This was posted by Lawrence Waters on the Truck Floor Training Facebook page, and it was also sent to me by a door hardware consultant / firefighter friend.  Anybody know what it is?


9 Responses to “Mysterious Hardware”

  1. Keith Pardoe says:

    Hi Lori,

    It looks like the “device” shown in the picture could be an artifact of something called a “Fox Police Lock”—one of the earliest types of door barricade devices to be commercialized. Here is a link to an article

    Below is a link to a picture of the Fox Police Lock…



  2. cda says:


    Check the top or bottom of the door and may find a plate, that a pin may have use to come out of

    Send picture of it along with entire door picture

  3. Andrew says:

    My guess is the hook or catch from an old stile hold open device. Or maybe some kind of fixture for a door security stop of some sort?

  4. Douglas2 says:

    It sure looks to me like an adhesive security plate of the sort that institutions used to secure computer hardware in the 80’s; e.g.: something like the plates from this kit:

    I don’t know why it would be centered on the back of a door.

    • MartinB (aka lauxmyth) says:

      So far, this is the best I see here.
      Have a look at this Cable Organizer by Byte Brothers

      That is what it is with a few coats of paint. But the fact it is mounted to a door suggests it was re-purposed as some sort of additional lock, or hold open device or alarm the door has opened. Best guess.

  5. Nelson Dayton says:

    Does the hook pull out, maybe with a chain or string attached? Used as a door hold open or a clothes line?

  6. Angela says:

    It’s a grenade. Just keep the pin in it and everyone will be fine.

  7. Edward Ong says:

    made by Qualtec to secure computer

  8. Pete Schifferli says:

    Douglas2 and Edward Ong got it right. Why it is on the door is a mystery, perhaps part of a jerry-built hold open device?

Leave a Reply