Laptop Hinge Technology

[Mark Bolton]

Sorry but this is just the way my mind works. Does anyone know what the mechanism/mechanics are behind how a laptop hinge maintains friction with so much use? I now have an Acer Ezel computer which incorporates two such hinges into the screen fold and I have just always wondered how in such a small hinge profile to they maintain friction over so many cycles? One would guess that in short order the hinge would become loose and flopy and the screen would flop open or closed but it never happens.

Just an inquisitive mind thing with nothing behind it.

I remember older laptops having a fairly large hinge area but the new ones, while the screens are much lighter, are just so small.

[Dan Hintz]

Does a spring go limp after only a few tugs? Think in those terms...

[Steve Peterson]

I have no idea either. My guess is a sideways mounted spring that always applies pressure against the rubbing surfaces. The hinges also have to provide a mechanism for wires to pass through without breaking after a few hundred cycles. Most have long horizontal wire runs that allow the wires to twist rather than bend.

Steve

[Mark Bolton]

I have read about friction hinges which use small clips or clutches of sorts pressed onto the axle/pin of the hinge. It still just mystifies me how the material holds friction over such a long period with such little surface area

[Phil Thien]

They're friction hinges:

http://www.frictionhinge.com/

No spring, clutch.

In the early days they went bad quite frequently, and hinge replacement was a pretty common job. Of course, notebook computers cost $2000 - $5000, fixing them made sense.

Now a problem we run into is hinges that actually get tighter over time, resulting in broken clamshell components. And now that notebooks can be had for $250, replacing parts isn't always the right move.

[Frederick Skelly]

They're friction hinges:

http://www.frictionhinge.com/

No spring, clutch..

Thanks for posting this link! I learned something new.

[Mark Bolton]

Had visited that link before posting but still wasn't quite clear based on thise renderings. That site does show clutches with tension maintained via a spring washer. After looking there I fugured perhaps a lot must be to do with the materials.

[Dan Hintz]

The roll pin and question-mark band are the two most common hinge types you'll see on laptops. The question-mark band goes back to the spring idea I mentioned earlier... unless you bend the loop past the deformation point, it will retain its grip for a very large number of iterations.