Trying to identify and date this adjustable in our local museum. It has an arrow to show the direction of grip. Marked in script Ru(maybe b)i(maybe a) Lower down marked "A Patent" No other markings that I can see.

I like the looks, is that what I have heard mentioned as a ratchet adj.

http://cgi.ebay.co.uk/VINTAGE-ADJUSTABLE-SPANNER-SAXON-GERMANY-/290586765475?pt=UK_Hand_Tools_Equipment&hash=item43a85228a3

check this out

Probably marked 'Rapid'
Maker unknown....

See: Vernon Nail auction,778 #2
http://www.wrenchingnews.com/nail-auction-2007/catalog.html

Also very similar to a german made wrench, with unreadable markings (Bush)

Thanks guys!

It looks a lot like my Cochran. This isn't mine but mine is just like it.

This style wrench seems to have been re-invented by several different makers over the years. I think the first one made was J. W. Calef patent covered under patents from 1880 and 1883, #226,490 & 273,461. There are also the following;
Larcoloy
Speednut
Cochran
L G Automatic, Red Chief Patent 1,160,160
Webb & Hildreth, Patent 874,269

In addition to these US made versions there are what I believe to be English and German versions of this style wrench. Mechanisms vary slightly but they are pretty much the same principle in that the handle operates a pivot or rack that opens and closes the wrench jaws.