I have a job that requires hinges on two doors set into a marble floor. These doors are about 1.187" thick. Outside dimensions about
15" x 30". weight about 100 lbs each. The doors fit flush into the floor. The only ideas I've come up with are using either compound hinges or using a hinge shaped like a banna clip that rides in a track. Anybody have info on how to design a compound hinge? Thanks, EricCan you machine the marble and add a serious steel support? If so, use Soss hinges. They make a 1" hinge, but it is hard to find. The hinges cost about $50 each, so you will need to spend $300 on the hinges alone. Then you will need a frame to mount the hinges and to hold the marble.
If you look at
Would the situation lend itself to using pivot pins rather than hinges? These could even be surface mounted on the bottom of the doors / floors, which would allow alignment and heavy duty strength..
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I will be building a platform for the marble. It will be a 1/4" thick aluminum plate with 1 x 1 x 1/4 brass angle bolted to it. The brass will form a rim around the marble which will be visible. There will also be a brass frame around the opening. So standing on the floor there will be a brass square flush with the floor surface. Thanks for the Soss link, it looks like they might work. If not, I can at least buy one and study it and learn how to build what the customer wants. ERS
Pivot pins will not work. These doors are flush with the floor surface. So the pivot point needs to be at or above the floor. If below, then the edge of the door on the hinge side will interfere with the opening edge. When finished the opening will have 1/32" maximum clearance all around the doors. The doors themselves will be touching or at most have .005" in the gap between them. This is for a fancy home. You would not believe all the suff I make for fancy houses. Like a 1000 piece run of brass finials for door hinges for just ONE house. The finished house uses all but a few of these finials. The remainder are to be stored at the house along with several other custom items so service people years later will have the parts to fix anything that breaks. ERS
Hey Eric,
You sure have me wondering how these doors will "lift", at 100 pounds apiece. Is there a visible handle, or a "button" somewhere to push? Will they be moved by plain manual force, or counterbalanced, or powered some way? After they move, how far will they rotate? Flat (180 degrees) or stand up (90 degrees) or somewhere in-between? When open, what clearance is required in the "opening"? When closing by intent or accidentally, is there a restriction to keep them from "falling"? And what purpose do they serve? Hard to believe that a house that would seem to be so special or expensive would need a "trap door" into some lower area.
Just curious. Take care.
Brian Laws>>
On Thu, 24 Jun 2004 7:43:59 -0700, Eric R Snow wrote (in message ):
If I have visualized this correctly the doors open UP into the room. Is there a counterbalance or are the doors powered? Lifting a 100 pound door by hand seems a bit much. Due to the tight clearances it would seem to me that the door(s) would have to lift vertically the same distance as they are thick before swinging open. Linear actuators, such as those used to adjust big TV dishes, could do the job (Possibly). A long arm running horizonally under the floor with a counterweight might work also.
Let us know what you finally do.
One more suggestion. Also consider the mechanism used for one-piece swing-up garage doors. These doors are only popular in parts of the US where there is no snow; I had not seem them until I got to SoCal.
The mechanism uses two arms of unequal length and offset hinge points. The resulting system is bistable -- either open or closed. Quite handy for you is that the commercial units available are already spring loaded and designed for about the weight you want to move. In your application a lock of some sort would be required on one edge.
This is access to plumbing and stuff. This door is in the basement. The owners will never enter this space. You can count on it. The doors will have assist up and down so one finger is all that's required to lift. Doors will open about 105 degrees. I believe the plumbing for the tub is some of what is accessed by these doors. The house had to have a larger than normal water line brought in so their 300 gallon tub can fill in one minute. This is a solid marble tub. I imagine the owners will not even enter the space above the doors either. These doors go into the same house with the leather tiles in the study. 1 foot square tiles. Sheese! ERS
In article , Eric R Snow wrote: :This is access to plumbing and stuff. This door is in the basement. :The owners will never enter this space. You can count on it. The doors :will have assist up and down so one finger is all that's required to :lift. Doors will open about 105 degrees.
I hope there will be some way to access the power assist when it fails.
"The major difference between a thing that might go wrong and a thing that cannot possibly go wrong is that when a thing that cannot possibly go wrong goes wrong it usually turns out to be impossible to get at or repair." Douglas Adams, in _Mostly_Harmless_
The power assist is passive. It will be supplied by gas springs. If they fail it will just be harder to open the doors. The rest of the doors in the were installed by someone else. But there must be some sort of safety. I'm sure that they all can be opened from the inside in an emergency. ERS
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