• Welcome to engineeringclicks.com
  • Hand powered elevators and dumbwaiters

    Discussion in 'The main mechanical design forum' started by Ham549, Jun 18, 2013.

    1. Ham549

      Ham549 New Member

      Joined:
      Jun 2013
      Posts:
      1
      Likes Received:
      0
      I have always been fascinated with elevators and have been doing research on hand powered elevators (and there smaller counterparts dumbwaiters). One thing I can't figure out is how the self retaining break system works.

      "The Sedgwick Automatic Brake Dumb Waiter
      Machines are a great improvement over
      all Automatic Lock and other Self-Retaining
      Machines, and are especially designed for pur-
      chasers who consider just as carefully what
      they are getting, as what they are paying.
      The Automatic Brake is independently sup-
      ported, thus relieving the machine of all end
      thrust, strain, and unnecessary wear."
      -Sedgwick catalog 1923

      I would really like to see an animated cad drawing of such a mechanism working. I would also like to know the equation for figuring out the ratio I know if you have a rope wheel that is 20" in dimater attached to a pulley that is 10" you have a 1:2 ratio, same as if you had a gearing of one gear having 5 teeth and the other having 10. What I don't understand is how to factor them into one equation a 20" wheel going to a 5 tooth gear going to a 10 tooth gear going to a 5" pulley. Also if I wanted to build one of these things how many parts are still available and how many would have to be custom fabricated?

      I will leave you with a video of a hand elevator being operated https://www.youtube.com/watch?v=1JfRpbVLCLc note how the car stays stationeary when he stops pulling.
       
    2.  
    3. suryanshastri

      suryanshastri Member

      Joined:
      Jun 2013
      Posts:
      7
      Likes Received:
      0
      oops

      I could'nt see video.b'coz error videos not found.
       

    Share This Page