Abstract: A modular lift system may include, but is not limited to: one or more lift segments each including: a lift-truss structure; and a drive shaft having at least one end-coupler, at least one lift assembly coupled to the lift-truss structure, and at least one drive segment including: a drive-truss structure; a drive motor coupled to the drive-truss structure; and a drive-coupler attached to the drive motor and configured to engage the end-coupler of the drive shaft.

Abstract: A motorized bottom masking assembly for variably masking a lower portion of a large curved picture projection screen, including a bottom mask movable to various heights along the lower portion of the screen having a rigid bar member defining the uppermost edge thereof, and at least three bar positioning lift assemblies located entirely below the bar member coupled to the bar member near opposite ends thereof and near the middle of the bar member. Each of the three lift assemblies include an elongated base track, a pair of lift arms arranged in upwardly converging inclined relation having lower end roller carrier assemblies guided by the associated base track movable toward and away from each other and having upper ends coupled together to the member, a lead screw coupled to the roller carrier assemblies, and a drive motor therefor for converging and diverging the associated pair of lift arms relative to each other to raise and lower the bar member relative to the base track.

Abstract: A mounting and operating assembly for a movable closure or door of a transaction security booth or enclosure or the like having an upright cylindrical configuration, including an angle-iron shaped cross-section mounting ring having an inwardly projecting horizontal flange to be secured to the top portion of the enclosure by circumferentially spaced fastening bolts, a double I-beam shaped track secured to the ring by bolts through the flange having a pair of cable idler wheels on each, a T-shaped carrier at plural locations above the closure secured to the latter and having pairs of roller wheels riding on the bottom flange of the track, a drive motor and worm gear box supported on the ring having a horizontal axis wheel driving a cable system trained about a pair of horizontal axis idler wheels and about the cable idler wheels defining the cable path and secured to at least one of the carriers to open and close the closure.