Principles of operation of the flintlock pistol continued
A Sidelock in the rest position
The tip of the mainspring (which is slightly compressed) is exerting downwards pressure on the toe of the tumbler, trying to rotate it – and the cock which is attached to it - towards the frizzen, but the tumbler cannot turn firstly because the ledge on the inside of the cock is resting on the top edge of the lockplate, and secondly because the nose of the scear is pressed into a notch on the tumbler. The scear spring is exerting downwards pressure on the scear, trying to turn it clockwise, but the scear cannot move because its nose is pressing up against the tumbler. The pan is open because the flint will not allow the frizzen to rotate far enough for the pan-cover to close.
A Sidelock at half-cock
Pulling the cock back has caused the tumbler to rotate against the pressure of the mainspring. The nose of the scear has slipped into the half-cock notch in the tumbler. Upwards pressure on the rear end of the scear (by pulling the trigger) cannot disengage the nose of the scear from the half-cock notch because the shape of the notch will not allow the scear to rotate and thus disengage. The pan-cover is now able to be closed, preventing the loss of the priming powder and also putting the frizzen into the correct position to be struck at the top by the flint. The mainspring has been further compressed. The ledge on the inside of the cock, which in the fired position rests on the top edge of the lockplate, can be seen in the right picture.
A Sidelock at full cock
Pulling back the cock still further has caused
the tumbler to rotate still further, and allowed the nose of the scear to
fall into the full-cock notch, while compressing the mainspring even
more. Now pulling the trigger will push the back end of the scear
upwards, rotating the scear until its nose releases from the tumbler,
allowing the tumbler and cock to rotate quickly so that the flint hits the
frizzen and scrapes down its face while the pan-cover opens exposing the
priming powder. A shower of sparks falls into the pan, igniting the
Copyright © Marsden B Robinson - 2012