Abstract: A vertical gear unit has a downwardly extending output shaft operably connected at its upper end to a motor and at its lower end to an impeller. A first housing defines a first lubricating oil sump and a second housing defines a second lubricating oil sump for collecting lubricating oil exiting from a bearing for the drive shaft, the lubricating oil having been supplied from the first housing. The first and second housings are vertically spaced about the output shaft with the first housing being disposed vertically above the second housing. A pneumatic purge is provided for supplying air into the second sump for increasing the pressure therewithin to a level above the pressure within the first sump. A conduit connects the first and second sumps, with the relatively high pressure within the second sump driving the lubricating oil collected therewithin upwardly into the first sump.

Abstract: A miniature slide storage tray having a plurality of annularly arranged, radially extending compartments for receiving and storing a plurality of slides in a compactly arranged manner so that the storage tray and slides require a minimum of storage space. An annular slide transfer tray having a plurality of radially extending compartments corresponding to the compartments in the storage tray is temporarily engageable with the storage tray and the mated storage and transfer trays are temporarily engageable with an associated, annular, slide projection tray. Alignment and indexing structure maintains alignment between the respective compartments in the storage, transfer and projection trays when these parts are in mated relationship.

Abstract: Relatively inexpensive slide storage trays are provided for use with a single slide projection tray. The slide storage tray has alignment and indexing means cooperable with the projection tray so that the trays can be temporarily mated for transfer of slides from the slide compartments of one tray to the slide compartments of the other tray while maintaining a predetermined arrangement or sequence of slides relative to the compartments. A pusher device may be utilized to facilitate transfer of slides from certain types of projection trays.