Abstract: An air circulation system including an enclosure, air circulating devices for conveying ambient temperature air into the enclosure, actuating apparatus for the air circulating devices including a supporting frame, an upwardly extending support member adjacent each end of the supporting frame, a pair of rods each having one end affixed adjacent the end of one of the support members with their free ends extending toward and spaced from one another, a mercury bulb switch suspended between the free ends of the rods, rod deflection assemblies disposed along the length of each of the rods, each of the rod deflection assemblies including an expandable fluid chamber mounted on the supporting frame and operatively connected to one of the rods, a sensing element operatively connected to each of the rod deflection assemblies, one of the sensing elements being located outside the enclosure and the other sensing element positioned inside the enclosure, each of the sensing elements including a sealed hollow bulb connected

Abstract: A wire-bending plier set for permanently twisting a portion of orthodontic arch wire about the wire axis to enable application of a torque force to a malpositioned tooth. The plier is configured to grip the wire at spaced-apart positions between which the twisting bend is to be made. A lever or key is then engaged with the wire between the gripped areas, and the key is rotated about the wire axis to stress the wire beyond the elastic limit and impart the desired twist.