Ball based hinges On small plastic boxes are sometimes found hinges that snap into place
to allow easy assembly and are made with two balls attached to the lid
and a disc with dimples in each side attached to the bottom of the box.
The lid snaps on and then can swivel as the balls slide in the indentations
in the disc. While metal does not have the flexibility that plastic does
a version of this hinge can be built where the spheres are pinched slightly
together after inserting the indented disc. Such a hinge can come apart
if pulled on hard enough but will function well if there is little stress
One can reverse the positions of the rounded parts by having the central
'knuckle' have rounded ends and be installed in sturdy tabs with rounded
indentations on the other side of the hinge. It is designed so that they
are open enough to just squeeze in the middle 'knuckle' and then are closed
over its rounded ends to install the hinge.
Alternative hinges (coils, sewing, fiber,
fabric, mesh, chains)
Since we defined a hinge as involving rotation of parts relative to each
other at a fixed point somewhere back in the beginning there are a number
of other kinds of solutions which satisfy this definition. Examples of
this include coil bindings on notebooks, sewing through holes in the material,
glued or mechanically fixed cloth or woven materials, mesh use and all
sorts of chains and jump ring based flexible systems.
Solving Design Problems
example of hinge with bezels on end-use as
thinking example-spell out analysis steps
An example of how this kind of thinking is applied can be seen in this
design sent to me by Phil Porier. He has used a hinge pin just shorter
than the hinge itself on each side and then tube set faceted round gems
into the ends of the hinge. I might recommend starting with the outer
knuckles a little wider than the width being hinged: this to allow for
metal removal during setting.