Scissor-arm Bridge 2011
Made to transport a small box acros a gap of one meter, the scissor arm is powered by two pulleys that activate in sequence to extend and then retract the arm. One half of the first scissor is held by a latch during extension, and at maximum extension this switches to holding the other half stationary. Thus the arm describes a convex arc on opening, and a concave arc on retracting, releasing the box onto its destination at the arm's final extension. Model is anchored to table by a high powered suction cup.
