# anyone understand card table hinges?



## phinds (Mar 25, 2009)

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.


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## Improv (Aug 13, 2008)

Your picture does not show the opposite side of the hinge. I suspect you need to look at the engineering in the jointing plate there. Look at the distance to where the joining plate connects to the hinges in the first and third pictures and compare that to the distance in the second picture.

Regards,
Steve

Edit: The joining hinge is also moving to the other side of the (I assume metal?) plate and your picture doesn't show any mode for that happening.


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## phinds (Mar 25, 2009)

Improv said:


> Your picture does not show the opposite side of the hinge. I suspect you need to look at the engineering in the jointing plate there. Look at the distance to where the joining plate connects to the hinges in the first and third pictures and compare that to the distance in the second picture.
> 
> Regards,
> Steve
> ...


I'm not following you at all, but it does SOUND like you're onto something about my problem.

As I understand it, there are two hinge points, the circles in my drawing, and they are tightly connected by a solid metal plate that has holes in it. Thus the distance between the circles cannot change at all. The motion of the arms is completely free and I've tried to figure out how that could make the "problem" that I see go away and it sounds to me like that's what you're describing, but I'll still not getting it.

Any chance you could do a sketch to show me what you mean?

Thanks


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## Longknife (Oct 25, 2010)

I have no personal experience of these hinges, but as you can see in the picture the distances "a" and "b" are not the same which indicates that there is some kind of slack in the connection piece.


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## phinds (Mar 25, 2009)

Longknife said:


> I have no personal experience of these hinges, but as you can see in the picture the distances "a" and "b" are not the same which indicates that there is some kind of slack in the connection piece.
> 
> View attachment 30134


The pic you posted is the same as what I used for the upper pic in my graphic BUT I now see that it is a totally bogus pic and is no help in solving the problem because the 3 hinges shown in the pic ARE NOT THE SAME HINGE. They have moved the hinge point in the pic on which you put the lable "B".

My graphic did not depend on this pic and I used it just to exhibit the full range of motion of the hinge and didn't notice that it was a bogus pic.

Still, I thank you for your attempt to help.


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## Longknife (Oct 25, 2010)

Well, then I guess you have to buy some and examin them. Just $24 a pair.........


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## phinds (Mar 25, 2009)

Longknife said:


> Well, then I guess you have to buy some and examin them. Just $24 a pair.........


Yeah, I've been looking for them ... just to LOOK at, not to actually buy. If I had to buy everything I put in the glossary, I'd go broke.


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## Chaincarver Steve (Jul 30, 2011)

Look at this picture. It may answer your question. I don't know, though. It looks like the ones you show are meant to mount on board edges. But I really can't tell. But the ones shown here: http://www.leevalley.com/US/hardware/page.aspx?p=40208&cat=3,41241,41261 are sunk into the table's top from the top so that the board's mating edges open AWAY from each.


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## phinds (Mar 25, 2009)

Chaincarver Steve said:


> Look at this picture. It may answer your question. I don't know, though. It looks like the ones you show are meant to mount on board edges. But I really can't tell. But the ones shown here: http://www.leevalley.com/US/hardware/page.aspx?p=40208&cat=3,41241,41261 are sunk into the table's top from the top so that the board's mating edges open AWAY from each.


You are right that the one you point to is a totally different type of hinge. It's the modern card table hinge and you're right about the old ones mounting into the edge of the table.


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## GeorgeC (Jul 30, 2008)

I am sitting here with a very puzzled look on my face. You all apparently know what you are talking about and I have no idea.

I have never seen a card table with a hinge on any part of it except the legs. What kind of card table has a hinge on something other than the legs? I gather that this must be some type of table that folds.

George


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## phinds (Mar 25, 2009)

GeorgeC said:


> I am sitting here with a very puzzled look on my face. You all apparently know what you are talking about and I have no idea.
> 
> I have never seen a card table with a hinge on any part of it except the legs. What kind of card table has a hinge on something other than the legs? I gather that this must be some type of table that folds.
> 
> George


Yeah, it's a very old style as I understand it, that is not much in use any longer, although you can buy them LOTS of places but the places that sell them don't show how they are used. As I understand it, there are wings on the table that fold over on top of the table via the edge-mounted hinge.

It's just something I ran across while researching hinges for my glossary. It IS a valid woodworking hinge, so I feel compelled to include it but I can't figure out how the damned thing works, which I find very annoying. 

There were a couple of other hinges that I didn't get right off, but it took very little effort to figure them out but this one's a stumper.


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## Shop Dad (May 3, 2011)

Paul, as you pointed out the 90 degree picture is "photoshopped" to move the hinge point. In fact it is a small rounded plate that holds to two together. The corners that you have circled in red are rounded as well so when the hinge moves the space between hinge points does NOT get any larger. If you could examine one you would see it's actually a fairly simple hinge. That pic totally throws things off. I've seen this used on the sides of tables and other things that fold.


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## phinds (Mar 25, 2009)

Shop Dad said:


> Paul, as you pointed out the 90 degree picture is "photoshopped" to move the hinge point. In fact it is a small rounded plate that holds to two together. The corners that you have circled in red are rounded as well so when the hinge moves the space between hinge points does NOT get any larger. If you could examine one you would see it's actually a fairly simple hinge. That pic totally throws things off. I've seen this used on the sides of tables and other things that fold.


Yes, I mentioned that the HINGE corners are rounded, so don't collide with each other but how can the TABLE corners not collide with each other given that the center-to-center distance on the hinge cannot change. I just don't see how it can be physically possible unless the edges of the table top are ALSO beveled but that would be unacceptable in a card table.

I KNOW there's got to be something I'm not seeing about how this works, but it's driving me nuts to figure out what it is?

Any chance of your doing a sketch to show me how it's possible?

Thanks for the help.


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## Longknife (Oct 25, 2010)

GeorgeC said:


> I am sitting here with a very puzzled look on my face. You all apparently know what you are talking about and I have no idea.
> 
> I have never seen a card table with a hinge on any part of it except the legs. What kind of card table has a hinge on something other than the legs? I gather that this must be some type of table that folds.
> 
> George


Here is a video on one




 
Phinds, difficult to see in the video, but doesn't it looks like a groove in the joint? Also note on 0:30 when he moves the upper leaf a little bit. Looks to be some slack there.


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## phinds (Mar 25, 2009)

Longknife said:


> Here is a video on one
> Concertina Hinge Card Table - Opening and Closing the table - Dorset Custom Furniture - YouTube
> 
> Phinds, difficult to see in the video, but doesn't it looks like a groove in the joint? Also note on 0:30 when he moves the upper leaf a little bit. Looks to be some slack there.


Yeah, I found that video among all the other stuff I found when I was reasearching the hinge, but all it told me was that the hinge DOES work, but I had already assumed that. I do see that there is a joint line in the middle but it doesn't look to me as though it has anything like the size of radius bevel that the hinge would require.

I could be wrong about that and in any event I appreciate your further attempt to help me with this.


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## dodgeboy77 (Mar 18, 2009)

I never saw a card table like that. It's really clever.

Bill - Who is now considering a new project to add to the list.


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## CNYCarl (Apr 16, 2011)

phinds said:


> 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.
> 
> ...


Stop looking at the hinge as two rotating elements and picture it as a system with slidng and rotating motions. You may have to model it to see what is happening.


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## phinds (Mar 25, 2009)

CNYCarl said:


> Stop looking at the hinge as two rotating elements and picture it as a system with slidng and rotating motions. You may have to model it to see what is happening.


already did that 6 ways from sunday and cannot get past the fact that if the distance between the two hinge points can't change (and I don't see how it CAN) and the card table edges aren't radius beveled (and it just doesn't seem to me that it would be at all acceptable that they would be), then there just does not seem to be ANY way this could work.

Since it DOES work, clearly I'm still missing something. Perhaps as longknife suggests the table edges really ARE beveled AND there's some slack.

I was convinced at first that there had to be some slack in the flat plate (holes bigger than the hinge pins) but that doesn't seem to be the case.


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## Chaincarver Steve (Jul 30, 2011)

Maybe the end near the hinged/pinned section is has to be rabbited so that the full thickness of the board is not present at the folding edge. In other words, the corners you circled in red may not even be there. I'm going to guess that rabbits or camphors are the missing detail here.


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## toycrafter (May 31, 2010)

This might not be the greatest idea but it might work. I understand you don't want to bevel the outside edge to gain more room to operate the hinge but what about a concave channel in the side of the table surface. I am posting from the phone so I can't draw a picture but I hope it makes sense anyway.


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## phinds (Mar 25, 2009)

Chaincarver Steve said:


> Maybe the end near the hinged/pinned section is has to be rabbited so that the full thickness of the board is not present at the folding edge. In other words, the corners you circled in red may not even be there. I'm going to guess that rabbits or camphors are the missing detail here.


No, the rabbits would be far worse than radius bevels because the radius bevels MIGHT not interfere with dealing cards across the table but rabbits absolutely WOULD interfer.


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## phinds (Mar 25, 2009)

toycrafter said:


> This might not be the greatest idea but it might work. I understand you don't want to bevel the outside edge to gain more room to operate the hinge but what about a concave channel in the side of the table surface. I am posting from the phone so I can't draw a picture but I hope it makes sense anyway.


I don't follow what you're saying, but in any case, nothing you do on the edge of the table is going to affect how those internal edges move relative to each other.


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## toycrafter (May 31, 2010)

Here is what I meant, sorry if my explanation didn't make sense. I hope the drawing makes more sense


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## amckenzie4 (Apr 29, 2010)

Looking at the video Longknife posted, I have an idea. At around 20 seconds, he opens the table. It looks to me as if he gets it open to around 120 degrees and the more-or-less vertical side shifts. More importantly, it sounds to me like it's just dropped against the supports. If that's right, then the connector plate between the two hinges is longer than the distance between the centers of rotation, and can slide freely on the centers. That would mean that the distance between the centers CAN change, which means all the wood edges can be square without the corners knocking together.

It would require kind of an odd mortise to make it work, I think, but it's the only explanation I can think of.

Edit: I looked again. There's a good close up photo here, inserted below, and I thought of another explanation.

Photo:










Take the hinge. Mount it so that the tallest part of each half (the far left in the photo)is flush with the edge of the two boards. Fold up the two boards. 

Now, when you unfold, think about what's going to happen. First, you're going to lift the edge of the top board without moving it sideways. At that point, the hinge is going to rotate at only one of the two possible rotation points, the one on the top hinge. Once the top board is perpendicular to the bottom one, and you pass the 90 degree mark, the bottom rotation point will start turning. Because there's a small gap between the two halves, even with square corners everything should fit just fine.

I'd have to build a model to test it, but I think that's right. The critical piece is that you actually have two centers of rotation, and there's a slight gap between the two boards when they're folded up. It probably can be small enough to be unnoticable, as long as it's there.


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## Chaincarver Steve (Jul 30, 2011)

phinds said:


> No, the rabbits would be far worse than radius bevels because the radius bevels MIGHT not interfere with dealing cards across the table but rabbits absolutely WOULD interfer.


No, no, no... on the UNDERside. Not on the top surface. The top could remain perfectly level and smooth all the way across. I am speaking, that is, as if the flaps fold in half downward. Perhaps I'm misunderstanding the fold direction.


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## Shop Dad (May 3, 2011)

I'm not sure that video shows these same hinges in action. I don't have a way to post a drawing at work here so I'll try to describe my understanding of these hinges:

The section of the hinge that connects the two sides is actually mounted proud of the table bottom. The rest of the length is flush with the table bottom. Ergo, nothing to restrict movement.

In your first rendering - the image of the upside down table top - imagine sliding the hinge upwards untill the arms are flush with the bottom edge. Not a hinge appropriate for every situation but functional.

That's my story and I'm sticking to it. :smile:


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## Chaincarver Steve (Jul 30, 2011)

If it does indeed fold UPWARD then toycrafter is likely on the right track.


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## phinds (Mar 25, 2009)

toycrafter said:


> Here is what I meant, sorry if my explanation didn't make sense. I hope the drawing makes more sense


Can't see any pic, just an "broken image" icon.


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## phinds (Mar 25, 2009)

Chaincarver Steve said:


> No, no, no... on the UNDERside. Not on the top surface. The top could remain perfectly level and smooth all the way across. I am speaking, that is, as if the flaps fold in half downward. Perhaps I'm misunderstanding the fold direction.


I though of that, but several pics convinced me that the fold is always so that the leaf fold onto the top of the table.


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## phinds (Mar 25, 2009)

Shop Dad said:


> I'm not sure that video shows these same hinges in action. I don't have a way to post a drawing at work here so I'll try to describe my understanding of these hinges:
> 
> The section of the hinge that connects the two sides is actually mounted proud of the table bottom. The rest of the length is flush with the table bottom. Ergo, nothing to restrict movement.
> 
> ...


Yeah, I though of that too, but with those little hinge sections proud of the table top, somebody bang their elbow on them and would then hunt down the manufacturer and hurt him.


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## phinds (Mar 25, 2009)

amckenzie4 said:


> Looking at the video Longknife posted, I have an idea. At around 20 seconds, he opens the table. It looks to me as if he gets it open to around 120 degrees and the more-or-less vertical side shifts. More importantly, it sounds to me like it's just dropped against the supports. If that's right, then the connector plate between the two hinges is longer than the distance between the centers of rotation, and can slide freely on the centers. That would mean that the distance between the centers CAN change, which means all the wood edges can be square without the corners knocking together.
> 
> It would require kind of an odd mortise to make it work, I think, but it's the only explanation I can think of.
> 
> ...


Yeah, the more I think about this hinge the more I HAVE to believe that the hinge plates are, as you suggest, drilled so that they have some play in them. I just can't see any other way it would work AND still be an acceptable, functional, hinge for a card table.

The mortise on these, by the way, IS a bit complex because the larger sections are also thicker.

Thanks for the discussion.

EDIT: Also, it has occurred to me that a way around the loose joint required by loose hinges could easily be overcome with a trivial pressure latch on the bottom of the table (although I have no indication that this is every DONE, and it certainly is not on the one in the video --- but then that one is NOT the normal design)


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## toycrafter (May 31, 2010)

phinds said:


> Can't see any pic, just an "broken image" icon.


I can see it, also in your quote. The image location is http://www.storybuildertoys.com/woodforum/hinge.jpg


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## phinds (Mar 25, 2009)

toycrafter said:


> I can see it, also in your quote. The image location is http://www.storybuildertoys.com/woodforum/hinge.jpg


 
Weird ... must be something wrong with my browser. I don't see it by pointing to the link, just get the same broken image icon.

I'll try a different browser.

OK, FireFox got it OK.

VERY clever. That would work, I think. Not sure if that's HOW these things work, but it's a great idea.

Thanks


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## NKYDarrell (Sep 14, 2009)

You are getting WAY too hung up on the joint being perfect. 

Here is an antique card table. as you can see there is a clear gap between the two pieces.


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## phinds (Mar 25, 2009)

NKYDarrell said:


> You are getting WAY too hung up on the joint being perfect.
> 
> Here is an antique card table. as you can see there is a clear gap between the two pieces.


FANTASTIC ... thanks for that. Now I'll be able to sleep tonight :icon_smile:


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## hnee (Apr 27, 2019)

Stumble on this and seems that it was not resolved. So here is my 2 cents.
From the picture, we see three different positions of the hindge. One this is fully folded without any marking, one with the letter "a" and the other with letter "b". It is obvious that the one with letter "b" does not make sense as the pivot point has moved and it is obvious that it is a result of PS work. To make it work, simply mount the board such that its bottom lines up with the pivot point in the image with the letter “a”. Think of the open position as a “T”, let the bottom of the T hang out below the table top when open and everything works.


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## FrankC (Aug 24, 2012)

The hinge opened to 90 degrees is not the same as the other two images, the mounting holes are not in a straight line as hnee pointed out.

Sorry just realized this was actually not the original question, OP realized one photo was bogus.


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## tinyumbrellas (Jun 25, 2021)

I know this thread is 10 years old, but for the edification of those such as myself stumbling upon it at the current time, here is a video which more closely shows this type of hinge in action, and tips for installation: Townsend card table step 29 and Townsend card table step 30
it was very useful to see the troubleshooting and adjusting, hope it helps someone!


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## allpurpose (Mar 24, 2016)

My desktop computer sets on an old solid wood card table. Now my curiosity is boiling up except it's covered in junk, paperwork and has about (insert some ridiculous number) of wires going all over the place and my ankle hurts. Damned you! 
I was hoping to work on cabinet doors this evening!


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## allpurpose (Mar 24, 2016)

Hmmm..I don't suppose you have this type of hinge do you? It's the only one I've ever seen of this kind.. Top isn't quite solid wood, but it isn't cardboard either like some..


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## tinyumbrellas (Jun 25, 2021)

Ooh interesting, that’s for the legs is it? The more common kind of card table around here not like the folding top ones we’ve been discussing. Can’t say I’ve ever seen one! Trying to imagine quite how it works…
I’m an amateur project maker not a woodworker though so someone may pitch in “oh that’s a thingummy hinge got tons in the garage”


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