Name this hinge

Discussion in 'General foundry chat' started by Zapins, Feb 3, 2020.

  1. Zapins

    Zapins Silver

    What is the name of the type of hinge that allows the desk in this photo to swivel?

    I want an industrial version of this for my new crucible hoisting mechanism.

    [​IMG]
     
  2. Jason

    Jason Gold Banner Member

    I don't think it's really a hinge. Swivel is what I'd call it.
     
  3. rocco

    rocco Silver

    Just to be clear, are you referring to the joint that allows the writing surface to swing up and out of the way or the one that allows the seat itself to swivel?
     
  4. Sheesh, anyone who knows anything about these things has seen an "Orrery" hinge before :rolleyes:
     
    dtsh likes this.
  5. crazybillybob

    crazybillybob Silver Banner Member

    We have some of those chairs at school. The writing surface doesn't swing up out of the way it just rotates. So both the table and the chair rotate using the same hinge. It's a tube over a tube with a retention pin (bolt) and a bearing surface (the high end chairs have a thrust bearing the cheapy ones we have just have a plastic bush) I would call it a pivot. The same thing that your lathe cross slide handle does just in a vertical orientation. The desk part just uses a plastic outer tube and a metal inter tube it's self bushing. [​IMG]
     
  6. rocco

    rocco Silver

    We had similar looking ones at my school, on those, the top was hinged like a trap door and once the top was completely vertical, you could rotate the top down along side the chair so it was completely out of the way and didn't intrude into the space of the adjacent desk as it would if the top just rotated
     
  7. Petee716

    Petee716 Silver Banner Member

    That was hi-tech back in the olden days! Lol. You're dating yourself my friend!

    I had to google that one!

    Pete
     
  8. rocco

    rocco Silver

    I'll fess up, that was the early 80's, the chairs might well have been considerably older than that.
     
  9. Zapins

    Zapins Silver

    The hinge under the seat here that lets the chair rotate back and forth. Just the part under the seat not the part near the floor/base

    [​IMG]

    [​IMG]
     
  10. Petee716

    Petee716 Silver Banner Member

    This is starting to remind me of Melterskelters rig.
     
  11. OMM

    OMM Silver Banner Member

    It is called a jib hinge. I think you should Google radial jib crane.

    I designed my lifting tongs so this could be added on.

    With a 180° sweep and if the lifting hoist is on a slider on the arm, and the arm is 8 feet long, it would allow for a large work area if the furnace is at one end of the 180° circle.

    I was thinking about building something like this out of aluminum.

    Wow, our PA store has them for $60.
    https://www.princessauto.com/en/detail/1-320-lb-electric-hoist-frame/A-p8667446e

    7AA80EF6-E8B1-453C-B7AD-83F1E2B73D07.jpeg
     
    Last edited: Feb 4, 2020
  12. crazybillybob

    crazybillybob Silver Banner Member

    WOW... with Shipping ($48.00) That makes it under $110.
     
  13. Jason

    Jason Gold Banner Member

    picks up 1300lbs?? Looks cheap enough. My time is worth way more than that to make one.
     
  14. OMM

    OMM Silver Banner Member

    The PA one is only box tubing and 43 inches long. It looks like a piece of junk. I was just looking at the junk store site to see if they had anything.
     
  15. Jason

    Jason Gold Banner Member

    Oh no hoist? I was wondering why the yellow hoist? Now that looks like a good setup. I'd want the ability to move the hoist in and out not just round.

    Wouldnt be that hard to build and for the same money in steel, youd have something much stronger.
     
  16. crazybillybob

    crazybillybob Silver Banner Member

    A bit of sch40/80 pipe for the pivot. An I beam with a hoist trolley on it . A 1" bit of thick wall Box tubing from the tip to the wall bracket. Cast a nice set of Bronze bushes for either and of the pipe/pivot. You're done. Say $50 -75 at the local scrap pile, and an afternoon with the welder. Electric hoist/chain fall going to run you more than the arm.
     
  17. Zapins

    Zapins Silver

    That is similar but not quite the same. The jib hinge pinches a tube between top and bottom stabilizing it on each end. The hinge I am looking at is like a tube with a thrust bearing on the bottom and a regular bearing on the top to prevent the tube from moving horizontally. Its all supported from one contact point.

    I could make one and have it machined and set the bearings but if they make something by a name I don't know I'd rather just buy it. I'll be going home on saturday and have a week off to work on projects before I get back to being flayed and whipped.
     
  18. rocco

    rocco Silver

    Google "chair strut" or "chair lift cylinder" and you'll find lots. FWIW, I've disassembled one of those and I wouldn't recommend using one on a foundry furnace, too many non-heat resistant plastic and rubber parts
     
  19. spelter

    spelter Copper

    I'd call this hinge form a gudgeon and pintle.
     

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