Abstract: A disposable mask for door hinge and butt plate hardware designed to be slided onto the hardware instead of being frictionally clipped onto it. The mask includes a flattened plate attached to a cylindrical body and is distinguished by a longitudinal crease defining a weakened line along the cylindrical body and a tab either on said plate or on said cylinder. After use, a screwdriver or human finger may be used to apply pressure to the tab causing the mask to break along the weakened line so that it falls harmlessly from the door hardware in two disposable pieces.

Abstract: A deployable crossed log periodic dipole array is made up of a plurality of bays spaced along a feed transmission line arrangement. Each bay includes a support centered on the array axis. Each bay also includes as antenna elements four long, straight, flat or slightly bowed springs or spring-like tape elements, each fastened at one end to a transmission line conductor. A retainer associated with each bay is rotatable about the cylindrical support and engages the spring elements, so that rotation of the retainer winds the spring elements against the spring resistance and stores energy therein. A locking arrangement simultaneously engages or disengages all the retainers. Simultaneous unlocking of the retainers allows the springs of all the bays to rotate the retainers and to unwind. As the springs unwind, they deploy. The transmission line arrangement includes two open two-wire transmission lines on a common axis. To reduce torques during deployment, each bay contrarotates relative to an adjacent bay.