Abstract: Holographic volume gratings in waveguide cells can be recorded using many different methods and systems in accordance with various embodiments of the invention. One embodiment includes a holographic recording system including at least one laser source configured to emit recording beams and a movable platform configured to move between a first position and a second position, wherein when the movable platform is in the first position, the at least one laser source is configured to emit a first set of one or more recording beams toward a first set of one or more stations and when the movable platform is in the second position, the at least one laser source is configured to emit a second set of one or more recording beams toward a second set of one or more stations.

Abstract: A rod hanger for securing a rod to a substrate includes a mounting portion configured for engaging the substrate, a rod receiving portion configured for receiving the rod and a connecting element configured for vertically displacing the mounting portion and the rod receiving portion. In addition, at least one anti-rotation element configured for engaging the substrate is provided on the mounting portion.

Abstract: In a powder driven fastening tool, a channel is included for feeding a strip of explosive powder cartridges to a firing mechanism. A trigger is included for actuating the firing mechanism, wherein the trigger is movable between a first position and a second position. An advancing lever is pivotally coupled to the tool, the advancing lever having a strip engagement portion for indexing the strip which extends into the channel. An advance link is cammingly engaged with the advancing lever and is operationally associated with the trigger so that the strip engagement portion is in a first position in the channel when the trigger is in the first position and so the strip engagement portion is in a second position when the trigger is in the second position.

Abstract: An improved form of flat plate collector of the type used for heating a fluid, such as water, using solar energy. The structure comprises a cast or molded body having a surface which is absorptive to solar radiation, above which is positioned a sheet of material transparent to solar radiation forming a flat hollow cavity through which a thin sheet of water is passed in contact both with the transparent material and the absorptive surface. The thin sheet of water acts both as a means for transferring energy from source to sink and as an interference filter as well. The cast body may also incorporate suitable plumbing passages and means for interconnecting a plurality of collector modules.