Pneumatically-operated rigid linear chain and sprocket actuator for deploying a vehicle snow chain traction system

A pneumatically-operated actuator for deployment and retraction of a vehicle chain traction system comprising:

• a pneumatic cylinder having a cylindrical chamber enclosing a piston that is pneumatically-movable bidirectionally;
• a sealed, lubricant-containing case rigidly affixed to the pneumatic cylinder;
• a rack formed from a series of equally-spaced roller pins secured between parallel walls of a rack frame, said rack installed within said sealed case and linearly slidable therein;
• a sprocket having a plurality of teeth that engages the equally-spaced roller pins of the rack, said sprocket being installed in the sealed case and rigidly affixed to a rotatable shaft that extends through a sealed aperture outside the sealed case;
• an actuator arm having a first end rigidly affixed to an end of the rotatable shaft, and a second end having a friction disc rotatably affixed thereto, said friction disc being equipped with a plurality of snow and ice chain segments;
• and
• a control rod having one end coupled to the piston, and a second end coupled to the rack, whereby as the rack is moved back and forth by action of the pneumatic cylinder, the actuator arm swings through an arc that moves the friction disc against a wheel of a vehicle on which the chain traction system is mounted.