Patent 4640564 Issued on February 3, 1987. Estimated Expiration Date: March 4, 2006. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
A faceplate body (16,30) has apertures (20,34) which are aligned with the receptacles (6) of an electrical outlet (4). A pair of shutters (46) are received between the front plate (16) and inner liner (30) of the body (16,30) and reciprocate between closed positions in which they block the apertures (20,34) and open positions in which they are adjacent to the apertures (20,34). Springs (58) bias shutters (46) into their closed positions. A lock (62) has a sliding member (64) that is biased by a spring (70) into interlocking engagement with the shutters (46). A release button (68) is secured to the sliding member (64) and may be pushed laterally to move the sliding member (64) away from the shutters (46) to allow one or both shutters (46) to be moved into their open positions. Each shutter (46) has a projection (52) with a finger tab (54) for moving the shutter (46) against the force of the springs (58). The projection (52) has a stepped configuration to allow the shutter (46) to be held open by a finger without obstructing the aperture (20,34).