In Crudgington and Baker, Volume 3, at page 246 there is reference to the Lancaster second model A (“Wristbreaker”) distinguishable by “the lack of a built in mainspring cramp”.
I cannot find any earlier references in Volumes 2 or 3 to the cramp under either Lancaster or Beesley’s patents.
I understand that the flat mainspring operated as a cocking lever. I would conjecture that the cramp screw operated an internal cam to disengage the mainspring from the lock mechanism before removing the locks.
This would avoid forcing the locks back in against spring tension with the risk of damaging the lock or inletting.
Last edited by Parabola; 03/12/23 08:20 AM.
