Abstract: A suspended ceiling grid member which comprises a web portion, an upper bulb extending along the top of the web portion, a pair of flanges extending outwardly from the bottom of the web portion, the flanges being adapted to support ceiling tiles, and a lower bulb extending downwardly from the flanges, whereby the lower bulb provides greater strength to the suspended ceiling grid member and also enhances the appearance thereof.

Abstract: A loudspeaker system includes at least two loudspeaker drivers, together with an electrical crossover network having filter circuits with at least two separate mutually exclusive frequency passbands. The filter circuits comprising the crossover network each possess brick-wall amplitude responses, i.e., passbands with very high band-edge amplitude vs. frequency response slops, on the order of 100 dB/octave in the better embodiments. The high passband band-edge slopes, which are realized by the inclusion of transmission zeros in the separate crossover filter transfer functions, takes together with further appropriate crossover filter transfer function synthesis causes the separate loudspeaker drivers comprising the loudspeaker system to function independently of one another in their contribution to total system acoustic output.

Abstract: A manually operated bag closure device comprises a housing, a plunger, a spring, and a key and is manually operable between a bag insertion position and a bag closure position. The device is manipulable with one hand to overcome the force of the spring and locate the plunger relative to the housing at the bag insertion position, the neck of the bag being inserted into the passage with the plunger then being released to allow the spring to relocate the plunger relative to the housing at the bag closure position to grasp the neck of the bag and close it airtight.