Card table hinges have been around for over 100 years and so clearly they work, but I can't figure out HOW they work. My problem is this: when the hinge is fully open, it makes perfect sense. When the hinge is fully closed, with the leaf folded over onto the top of the table, it makes perfect sense. Everywhere in between makes no sense at all to me, which tells me there's SOMETHING about how these hinges work that I just don't get.
Here's a diagram to show what I mean. When the hinge is 20 degrees up towards being closed (bottom of pic) the edges of the table (according to my understanding) would dig into each other as shown in the black triangle.
The hinge corners don't dig into each other but that is because they have a radius bevel (they are round corners) but you would NOT do that to the corresponding card table edges and have a groove running all the way across the table --- that makes no more sense than the edges digging into each other.
If the hinge plate, that goes between the two centers of rotation, were elastic in some way, that would fix the problem, but it seems to be just a flat plate with holes and the holes can't be loose (overdrilled) because that would allow a gap to open up in the table top.
I've looked at this every way I can figure and I just don't get it.
Anybody know what the heck I've got wrong on all this?
Thanks for any help.
Here's a diagram to show what I mean. When the hinge is 20 degrees up towards being closed (bottom of pic) the edges of the table (according to my understanding) would dig into each other as shown in the black triangle.
The hinge corners don't dig into each other but that is because they have a radius bevel (they are round corners) but you would NOT do that to the corresponding card table edges and have a groove running all the way across the table --- that makes no more sense than the edges digging into each other.
If the hinge plate, that goes between the two centers of rotation, were elastic in some way, that would fix the problem, but it seems to be just a flat plate with holes and the holes can't be loose (overdrilled) because that would allow a gap to open up in the table top.
I've looked at this every way I can figure and I just don't get it.
Anybody know what the heck I've got wrong on all this?
Thanks for any help.