Automatic traffic control gate

Claim 1

An automatic traffic control gate, comprising: support means; a shaft rotatably mounted on the support means; an arm carried on the shaft so as to be movable therewith as the shaft is being rotated from a generally horizontal, lower position toward a raised position; power means mounted in the support means, the power means having a rotatable output member; an outer tube mounted on the support means; an inner tube telescopically, slideably mounted in the outer tube; a pair of trunnions mounted on opposite sides of one of said tubes, and a pair of elongated hangers having their ends connected to the shaft and their lower ends journaling the trunnions; lever means connecting one of said tubes to the shaft such that as the inner tube and the outer tube are moved in a relatively slideable motion in a first direction, the shaft is rotated in a first direction to raise the arm, and as the inner tube and the outer tube are moved in a relative motion in the opposite direction, the shaft is rotated in the opposite direction to lower the arm; an elongated screw disposed in said inner tube; a ball nut mounted in the inner tube and connected to the screw to longitudinally move the inner tube with respect to the outer tube in either said first direction or said second direction depending upon the direction the screw is being rotated; and slip clutch means connected between the power means and the screw to rotate it along its longitudinal axis but to permit the power means output member to rotate with respect to the screw whereby the output member is rotatable independently of the motion of said shaft.