slider

A slider is a small rectangular piece of fabric with a grommet near each corner used to control the deployment of a "ram-air" parachute. It is a type of reefing device. A ram-air parachute / parafoil has a tendency to open very rapidly. At high velocities, the opening shock from a rapid deployment can cause damage to the canopy or injury to the jumper. The slider was developed as a way of mitigating this. During deployment, the slider slides down from the canopy to the risers. Air resistance slows its descent. The slider holds the lines together, which slows the parachute inflation. The slider also deflects some of the rising air column away from the center of the canopy as it inflates. This also helps moderate the speed of opening. This invention solved the rapid deployment problem with ram-air designs. Sliders also reduce the chance of the lines twisting to cause a malfunction.