This article describes the design of a new binding for Alpine skiing wherein the release level of the toepiece in twist is modulated based on the level of neural stimulation of one of the vastii muscles in the quadriceps group. A conventional binding toepiece that relies on the force of a compressed spring to resist the release of the boot was modified. To modulate the release level to either a high or a low state, a special solenoid activated mechanism that alters the binding spring constant was designed. The design details of this special mechanism are described and the computations necessary to ensure reliable activation with a low force solenoid are summarized. Also described is the special circuitry that was designed to actuate the solenoid. To demonstrate the workability of both the mechanism and the circuitry, a prototype binding system was constructed and tested. The results of this testing are described as well.
Kevin Eseltine is a research engineer and Maury L. Hull is a professor in the Department of Mechanical Engineering, University of California, Davis, CA 95616.