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SP Tech uses iglide bearings and igubal spherical rod ends in the articulation of a sit-ski, a seat that is rigidly fixed to a pair of skis for use by paraplegic cross-country skiers. To improve their skiing ability, a 3-dimensional mechanism was designed which adjusts the height of the seat, advances one ski differentially, twists the skis and tips the seat with only the application of a force from the ski poles.

The pivot points were exposed to difficult conditions: vibration, random forces, high impact and cold, wet snow. The mechanism consists of two parallelograms ganged together by a four-bar linkage. The legs were connected to the seat using plain bearings. The 3-dimensial mechanism has 23 pivots of which nine are iglide plain plastic bearings and the remainder use igubal spherical rod ends. Plastic bearings are also used on the quick release tie downs, the device that locks the skis to the seat.

An SP Tech spokesperson believes igus products were the right choice for the job.

“The lightweight and self-lubricating properties, as well as the ability to operate in cold, wet conditions, made iglide and igubal an ideal choice for this class of outdoor sports equipment.”