Abstract: A rotary circuit selection device (400) having a driving cam (430) and an operating cam (440), each having a series of alternating peaks (442) and valleys (455). A biasing mechanism (420) biases the driving cam toward the stationary cam such that the peaks of one cam are received by the valleys of the other cam and vice versa. Selection of an alternative circuit includes rotating and translating the driving cam in relation to stationary cam.

Abstract: An environmentally sealed key switch assembly has a key pad formed from a plurality of individual keys preferably arranged in rows and columns. A first elastomeric sheet has a plurality of holes corresponding to positions of keys in the key pad. Each hole stretches around a corresponding one of the keys in order to provide an environmental seal. A second and unbroken elastomeric sheet stretches under the keys to provide a second environmental seal. The keys press downwardly upon, stretch, and deform the second elastomer sheet and thereby operate an electrical contact. When the key is released the memory of the elastomeric sheets provide a return force to restore the key to normal.

Abstract: An air vent system having an inner tube slidably disposed within a liner. A lock mechanism is mounted at one end of the inner tube. A lock pin is disposed at one end of the liner and is constructed to engage the lock mechanism such that the air vent system can be selectively moved between an open position and a closed position.