The AeroCrank™ Crossbow Crank


Loaded with 3 independent patent claims and 17 depend patent claims, the AeroCrank is one of, if not the, most scientifically advanced and engineered units we at Firenock have ever designed and produced.  Truly re-thinking every part of how a crossbow crank should work and has worked, the AeroCrank is in a league of its own -- once you buy one, you'll never have to buy another crossbow crank again.

[The AeroCrank] does not make a ratcheting noise when a crossbow string is pulled for latching.
— Dorge Huang

This quote is pulled from the first line of the "Field of Invention" section of the US Patent surrounding the AeroCrank.  In essence, the AeroCrank's design was focused on making a silent ratchet.  Why is such a distinction important?  To best understand to that question, we have to first uncover what a ratchet is and does.  Simply put, a modern ratchet involves a wheel, a pawl, and an anti-reverse system that work together to enable effective motion.  While our AeroCrank includes and does these things, our AeroCrank's ratchet also involves something else: another pawl.  Working simultaneously, our ratchet's pawls allow our AeroCrank to be truly quiet during use.  Read on to discover how.

Two-Pawl Ratchet System (US Patent # 9752844)

To make a silent ratchet system, we quickly discovered that the answer lies within enabling the wheel of the ratchet to go both forward and reverse freely both efficiently and perfectly. So how did we do so? With a very special and unique two-pawl ratchet system.  Let's then start with the pawls.  Involving only a dog and a fastener, a simple pawl is defined as a pivoted lever whose free end engages with the teeth of a wheel via a spring.  Our pawls involve a bit more (see image to the left below) components and do what a simple pawl does (engage with the teeth of a wheel) but only at a very specific time and without a spring -- we'll get into that later.  First off, the components.  For each pawl, there are a total of four components: the dog, the ratchet control clip, the screw fastener and the bushing.  

The dogs and the ratchet control clips.  Permanently gripping the wheel and press-riveted to each other, this unit is the key to our silent ratchet.  Deigned at very calculated angles from one another, these components do something radical when the wheel is in motion: they become disengaged from the wheel and, using friction due to the constant contact the ratchet contact clips have to the wheel, they move along with and then away from the wheel, removing themselves out of play (see image to the right below).  Without the dog in play, they never touch the wheel and "click" along with its movement.  But why have two pawls?  To best explain our answer, we have to discuss something we call the anti-reverse cage.  Shown upon the cog in the image on the left below, the anti-reverse cage is what allows users to stop the ratchet from moving freely.  But, due to the ratchet contact clips allowing the wheel to move without the engagement of the dog, the only time that the dog does becomes engaged is when the anti-reverse cage is brought up to limit the wheel's movement.  See, the moment when the teeth finally engage with the wheel, if they are not exactly at the start of the slot of a tooth, they have to travel to the next tooth.  Yet how far do they have to go?  To calculate that distance, you take 360 degrees and divide it by the amount of teeth are on the wheel.  So let's do so for AeroCrank.  360 degrees divided by 15 teeth 24 degrees.  24 degrees, a small distance, but what if we could make that distance smaller?  Immediately, most would say that we should just add more teeth.  But that exponentially decreases the strength of the system.  Others use a bit more complex approach, using a one-way ball bearing.  But that wears and can only withstand a minimum amount of pressure.  So, instead, never wearing and able to bear significantly more pressure, we used two pawls.  For then, in the rare case of one missing, the current dog would only have to travel 24 degrees divided by 2 -- 12 degrees -- before catching on the second pawl. Lastly, made of titanium and brass respectively, the screw fastener and bushing further assist in allow the pawls to pivot and move accordingly.

  Note :  This image is a not a true representation of the placement of pieces within the AeroCrank. This layout is simply here to display the individual pieces of this pawl and wheel system.

Note : This image is a not a true representation of the placement of pieces within the AeroCrank. This layout is simply here to display the individual pieces of this pawl and wheel system.

The Spools and Webbing

As in most cases, ratchets are designed to do more than turn.  Working fundamentally like every other crossbow crank, our ratchet system works with two spools of string that end in hooks to attach to your crossbow string for cranking.  This is where our AeroCrank stops being similar, however. There is something that happens when spools are used simultaneously that is often ignored: de-stacking. Or, in other words, the collapsing of a stack of string.  Especially with two spools that are simultaneously working and re-stacking together, the chance for one of the spools to collapse is high.  Fortunately though, we did not ignore and have taken preventative measures against this problem.  Our spools and string,  which in fact is not a string at all, but instead, a webbing, work together to eliminate the chance for collapse.  Observe the image below.  What's special about it?  The spool is the same diameter as the webbing itself.  When stacking, the webbing can only stack onto of itself, never beside or slightly upon itself, causing inconsistency.  Further, due to the flat nature of the webbing, it can never roll like standard string.  The chance for collapse truly becomes nonexistent. 

The Quick Detachment System

Perhaps the most straightforward yet significant feature of our AeroCrank, the quick detachment system allows a user to do exactly as its label implies: remove the crank.  Built compactly, sturdy, and weighing less than a pound, the AeroCrank is equipped with a wedge dimple lock system  to ensure that your crank will only be moved when you want it to.  (Which is whenever you want to switch between your crossbows, of course; they only thing you need to do is purchase another mounting wedge.)