A common problem in the sport of archery arises when an arrow becomes lodged in in a target after it is shot from the bow string. Typically the frictional force holding the arrow is too great for a human hand to overcome. Additionally, the archery arrow shaft does not provide a sufficient point for gripping if one did want to pull the lodged arrow from the target. Typical arrow puller models on the market include rubber grips that fold over an arrow's shaft to give the user a position from which to dislodge the arrow.
Lodged arrows in a target.
Typical arrow puller product.
I started developing a more complicated arrow puller device that was based on mechanical advantage. I wanted my concept to include characteristics of an over-center hinge.
Completed arrow puller computer model with slight variation. Click Arrow Puller Computer Modeled Parts for the individual parts.
Arrow Puller Computer Modeled Parts
The finished arrow puller prototype was made out of aluminum and rubber from laboratory vacuum tubing. The arrow puller works by relying on a grip force from the user that is translated mechanically into both a force to tighten the rubber around the arrow shaft and a force to push off against the target in which the arrow is lodged. The push rod is specifically designed only to mechanically dislodge the arrow a small amount to overcome the initial frictional forces to allow you to pull the arrow the rest of the way by hand. By overcoming the initial large frictional forces in a controlled mechanical fashion arrow removing becomes a safer task.
