Oldaro
07-18-2005, 04:50 AM
I'm playing with an idea, trying to rethink the good and bad sides of the crossbow. It is an old weapon, sure, but can the advantages of new materials and tools also influence its shape?
I tried here to take advantage of the new parallel limbs principle which worked so well with the vertical compound. In order to do it, I had to overturn the working parts, and this proved to be satisfactory in several important ways.
First, by anchoring the limbs near the middle of the stock, the Compact CrossBow (let's name it CXB for short) has its weight re-distributed toward its centre. In the same sense, the forward part of the stock doesn't have to be so sturdy any longer, because there are no more significant forces to contain at the front. Thus, this part can be made lightweight, for it only holds the front sight, handgrip, string silencers, bow-cocking shaft, and the bolt slot.
The bowstring working direction, having been turned around, puts the bowstring as far forward as possible, and that is the most important new feature. Practically, the brace height isn't deducted from the power stroke length. The power stroke becomes equal to the draw length! This means that the bow pushes the bolt for its whole length, therefore giving out its total amount of KE, i.e., more energy transfer to the bolt is not possible!
What of the excess energy remained, works itself out twofold. First, it vibrates itself at right angles to the bolt flight, which doesn't destabilize the bolt slot, and there are no vibrations in the sense of a "recoil". Secondly, there is a type of string shock absorber in the forward part (united with the pinguard profile) which reduces the string slap by means of two neoprene blocks set into their respective receptacles.
I'll explain the Push To Draw mechanism to the manufacturer interested in building the prototype, but in short, to draw the CXB, you pull out a telescopic-looking shaft all the way out, until the two "teeth" engage the string. Then you push the shaft against the tree or ground. The shaft slides into the stock, carrying the bowstring into the locking mechanism. By one special move you disengage the teeth and take them out of the string path.
The bow is cocked, it's profile becomes sleek and narrow, easy to move and handle in a tight space.
Please study the drawing and feel free to criticize whatever in your opinion doesn't hold water.
NOTE: This idea, same as every other I presented in this Forum, is free to every serious manufacturer. It serves to better our sport and life.
I tried here to take advantage of the new parallel limbs principle which worked so well with the vertical compound. In order to do it, I had to overturn the working parts, and this proved to be satisfactory in several important ways.
First, by anchoring the limbs near the middle of the stock, the Compact CrossBow (let's name it CXB for short) has its weight re-distributed toward its centre. In the same sense, the forward part of the stock doesn't have to be so sturdy any longer, because there are no more significant forces to contain at the front. Thus, this part can be made lightweight, for it only holds the front sight, handgrip, string silencers, bow-cocking shaft, and the bolt slot.
The bowstring working direction, having been turned around, puts the bowstring as far forward as possible, and that is the most important new feature. Practically, the brace height isn't deducted from the power stroke length. The power stroke becomes equal to the draw length! This means that the bow pushes the bolt for its whole length, therefore giving out its total amount of KE, i.e., more energy transfer to the bolt is not possible!
What of the excess energy remained, works itself out twofold. First, it vibrates itself at right angles to the bolt flight, which doesn't destabilize the bolt slot, and there are no vibrations in the sense of a "recoil". Secondly, there is a type of string shock absorber in the forward part (united with the pinguard profile) which reduces the string slap by means of two neoprene blocks set into their respective receptacles.
I'll explain the Push To Draw mechanism to the manufacturer interested in building the prototype, but in short, to draw the CXB, you pull out a telescopic-looking shaft all the way out, until the two "teeth" engage the string. Then you push the shaft against the tree or ground. The shaft slides into the stock, carrying the bowstring into the locking mechanism. By one special move you disengage the teeth and take them out of the string path.
The bow is cocked, it's profile becomes sleek and narrow, easy to move and handle in a tight space.
Please study the drawing and feel free to criticize whatever in your opinion doesn't hold water.
NOTE: This idea, same as every other I presented in this Forum, is free to every serious manufacturer. It serves to better our sport and life.