For those who have already watched my animation on the auto-opening pan cover mechanism of matchlock firearms, this video will delve deeper into the subject. While I strive for accuracy, there may be instances where I misspeak or present information that could be refined. I view this as a collaborative discussion, so please feel free to share your questions or thoughts in the comments section. There's a good chance another knowledgeable viewer might offer valuable insights. Now, let's begin today's video.

Why I Chose to Create This Animation

Firstly, my decision to finally delve into this vintage mechanism was spurred by a video from an Argentinian gunsmith. Notably, the auto-opening pan cover matchlock is one of his products. In his video, he not only elaborates on his matchlock but also provides a wealth of intricate details. This immediately ignited my curiosity to understand its internal workings.

Next, I created this animation as a tool to better articulate its operational mechanics. To be honest, before developing the animation, I always assumed this type of auto-opening pan cover would be an extremely intricate device, filled with numerous small components like gears and levers. However, it's actually quite a simple mechanism, potentially even rooted in the design of the original European pressure matchlock. Now, let's delve into the specifics.

‘Two Subsystems’

Essentially, if we consider this auto-opening pan cover as the primary system, it then comprises two subsystems: ‘the trigger system’ and ‘the pan cover opening system’.

Alright, let's first examine the components present in each layer. The base layer, naturally, is the plate. Moving upwards from the bottom, the second layer consists of the pan cover's lever and its spring. The third layer houses the trigger lever and its spring, in addition to the spring of the pan cover release button.

The Trigger System

The trigger system. Fundamentally, the way that the cock is secured to the plate and the design of the trigger lever are largely consistent with a conventional matchlock trigger system. The most significant divergence, however, lies in the spring placement. In a common matchlock, the spring is typically centrally located. Yet, to free up space for the pan cover opening system, this trigger spring has been relocated to the rear of the trigger lever.

The Pan Cover System

Now, let's discuss the most crucial component: the pan cover auto-opening system. Initially, I always envisioned a mechanism involving a gear, where the trigger would engage it, causing it to rotate and, in turn, open the pan cover automatically.

However, upon examining various matchlock mechanisms—both antique and modern reproductions—I discovered a consistent design. There's no gear involved; instead, an unusual, two-pronged lever is at play. One prong connects to the pan cover, while the other interacts with the trigger lever. This means that when you pull the trigger, the trigger lever presses down on this second prong, forcing it to bear the load. Consequently, the trigger lever actuates the pan cover's lever, causing its top prong that connected to the pan cover to make the pan cover slide open.

Release the Pan Cover

Finally, the top prong of the pan cover's lever is secured by the pan cover release spring. This suggests that the pan cover release spring likely features a tooth designed to engage with and hold the top prong of the pan cover's lever. This setup closely resembles the operating principle of a snap matchlock. Thus, the entire auto-opening system is achieved: the pan cover automatically opens simultaneously with pulling the trigger. It's truly a convenient and ingenious yet simple design. What's more, after firing, this pan cover can also close automatically. By simply pressing the pan cover release button, the lever, propelled by its spring, can retract and, in turn, cause the pan cover to close automatically.