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Old 20th July 2019, 10:37 PM   #28
Philip
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Join Date: Dec 2004
Location: California
Posts: 620
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Quote:
Originally Posted by fernando
Rick, much obliged for the kind words .
... And, no sir; you don't need an extra movement to disengage the safety device. The hammer 'round' foot is designed in a way that, while having an insertion to hold the safety device in half cock position, is also built in a manner that pushes it off, when you roll it around and up to full cock position.
... If i make myself understood.


.


Obrigado, Nando. I examined my locks again, and what you say has opened my eyes to what I had wondered about but didn't understand at first. There is a subtle bit of mechanical engineering that enables the effect that you describe. The três parafusos lock A and the fecho meio à portuguesa e meio à franzesa B in the images previous have the cock base shaped with a little projecting "tongue" below the safety engagement notch -- As the cock is pulled back fully to arm the mechanism, the rotating base makes this tongue push the brake out of the way, allowing the cock to travel its full arc to contact the frizzen. Ingenious!

What we have here is what mechanics call a "cam", and there is prior application in the case of wheellocks, whereby a cam turned by the rotating wheel spindle pushes the pan-cover activating arm forward on its pivot to open the pan and expose the priming powder.

I am now a lot more enthusiastic about the Portuguese brake than i was before now. Whether this will grow into Daehnhardtian exuberance depends on whether I can get used to the idea of using two hands to activate a safety mechanism, as opposed to the convenience of half-cock.
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