Started work on a new stock gun today, a 12b RUL Hammergun by A Maloch of Stirling and found a very rare rebounding lock mechanism inside. Patented by Stanton 2 years after his commonly found patent, I have never seen an example of it before. The spring would be a nightmare to make so thank goodness everything is nice and shiny inside!



Plus it has a rare Loaded Indicator mechanism, very reminiscent of the Dickson round action's gold washed pins. The left pin on this has been broken but it should be easy to rebuild with a little TIG magic!





Lovely classic, early engraving.

Neat. I can see why it wasn't used much.

Is there a little roller on the U-shaped piece?

Thanks for sharing.

OWD

Looking at the spring you can see why this system did not catch on .

OWD: Yes, a neat little roller secured with a threaded pin.
The picture in the Baker/Crudgington book shows the bar action version of the mechanism: similar but the other way up.
Although I agree that the spring is a nightmare, I think he designed this to get round a common problem with converting back-action locks to rebounding: lack of room.
As you can see it doesn't rely on the 'passive arm' of the spring reaching the tumbler like the normal Stanton rebounding lock mechanism. This lock beautifully illustrates the problem of the sear spring being in the way.
I suspect that this gun is a conversion from non-rebounding as the normal Stanton patent is perfectly suited for a back-action lock providing it is designed around it. However, as soon as the sear spring has been fitted in the usual non-rebounding position it often makes a normal conversion much more difficult, involving blanking off the sear spring pin hole and refitting it in a different place.
In fact, I think that one could use the general idea with a normal non-rebound spring, fitting a roller instead of a swivel and adding a suitable shaped extension to the tumbler with a cam shaped to suit.
I must try it some time soon!
Sorry if that offends anyone!

Need is the mother of inventions and limited space along with the need to avoid other patents creates some amazing designs. While your example was difficult to make, with that spring system, no on can dispute it has passed the test of time. Anything that last a century without major repairs is a fine design in my books.