Mitre clamp

[loftyhermes]

Picked up this clamp at a boot sale on Sunday only because I've never seen one before. It has two serrated rollers that turn and push the wood as it tightens. The words patent and roller are only two words on it, so if anyone knows when and by who it was made I would be grateful.

 

[AndyT]

I've got a couple of those. I think I did manage to track down the patent but I'm not able to look it up at the moment. I might have posted it on here somewhere.
Quite an effective clamp for the right size workpiece.

 

[AndyT]

Here you are.

old-tool-cleaning-part-4-general-cleaning-with-reviver-t64945.html?hilit=Patent%20clamp&start=15#p966122

1897 apparently. Might well be on Espacenet if you want the full story.

 

[custard]

I suspect (but don't know for sure) that this style of clamp was designed for picture frames, the moving internal grip would connect inside the frame rebate, where it doesn't matter if there's some light damage as it's invisible in the finished product.

I have some more modern mitre cramps from Morso (the mitre guillotine makers) that work on a similar principle, they grip within the rebate and push the joint together. I use them for making mirrors and they're superb.

 

[AndyT]

I suspect (but don't know for sure) that this style of clamp was designed for picture frames, the moving internal grip would connect inside the frame rebate, where it doesn't matter if there's some light damage as it's invisible in the finished product.

That's a good description of what happens. I may have read about it in the patent, or possibly in an old woodworking magazine. It also makes sense when you pick one up and try it out.

 

[loftyhermes]

Thank you Andy and Custard for your answers, yes it does look like it's well suited to making picture frames, will give it a go the next time I make a frame. Patented in 1897, I wonder when they went out of production. Still a bit more investigating to do.

 

[AndyT]

IIRC, they were still in Melhuish catalogues in the 1920s.