Tootler,Yes the possibility of extension of the 1829 patent condition by a new application 1844 has been suggested several times but after all the time turnover does not quite seem to match despite being 'near' (or rather more than..) 14 years and since the factual claims are not obviously related I *guess* that it would not have been a probable success either. It seems obvious anyhow that other makers started to pop up in the first years of 1850s... Scates, Case, Jones...and that means anyway that no 14 years after 1844 had any importance for "concertina rights" in practise and we have not heard of any legal actions have we? Patenting business has always been a nuisance as it seems - often ruining the inventors who may achieve some fame at the best but rarely fortune...

Looking at the technical standard of the 1829 application I have no idea what other ones looked at those days for comparison but the 1844 papers show a much more relevant set of figures anyway and the text is more stringent as well.Maybe 'times had changed' meanwhile or maybe
the applicant had done so too?...