Abstract: A window assembly for use in mass transit windows has a frame, a windowpane sized to fit within the frame, a removable sacrificial glazing panel covering or protecting one side of the windowpane, and a self-locking seal assembly biasingly securing the removable glazing panel towards the windowpane without the need for screws, drills or welds. The seal assembly has a first interlocking arm provided with a locking lip, and a second interlocking arm with a receiving groove which is biased from its free position into a locking position in locking engagement with the locking lip of the first arm. Preferably the locking arms are unitary with the seal assembly. The locking arms may be disengaged and the sacrificial glazing removed and a new sacrificial glazing panel installed without removing or disassembling other components of the window assembly.

Abstract: The closure counter-balance is for attachment as a strut between a hingedly mounted movable closure and a support structure. The counter-balance includes a pair of tubular members telescopingly connected together in sliding relationship. A compression coil spring within the members urges the members apart. Means are provided to frictionally lock the tubular members together in any given relative position thereof. Means are also provided to pivotally attach one end of the counter-balance to the support structure, said means including a release mechanism for easy disengagement thereof. The other end of the counter-balance is provided with latch means which cooperate with means on the support structure to lock the counter-balance in the closed position.