The engineering refinements of the QC class cases were largely developed during the creation of over 800 drawers for the Museum of Anthropology at the University of British Columbia in Vancouver. Fifty of the drawers in this installation were 3 meters wide by 1.2 meters deep and weighed 150 kg. The vertical drawers realized for the philatelic collections of the Postal Museum in Washington represent a further evolution of this technology.
This class includes units that have horizontal drawers or vertically arrayed pull-out display enclosures. They are often used in open-storage configurations but can be used in more typical exhibit areas as well. Their casing is made of sheet steel, optionally covered with other materials. The cases are designed to carry drawers or pull-outs with different capacities and dimensions.
These drawer cases can also be used as part of a compound unit with a display case on top that isn’t fastened to the drawer case and is completely independent. Display cases that can be used in this manner include door-opening, glass-case and table units. The drawer units are always meant to be fastened to the floor because if several drawers are open at one time – especially if the drawers are heavy – there is the risk the entire case could tip over.
Each drawer or sliding component can be independent of the others and can be conceived as an actual display case of its own. This means that these units meet the same preventive-conservation and security requirements, including high-level airtightness, RH passive control, customized lighting and security locks. All drawers are made of specially shaped and reinforced sheet steel.
Horizontal drawers can have tilt-opening glass lids while vertical drawers can have glass lids that rotate open.
The load-bearing plane is fitted with reinforced cross bars. Drawers can be opened by means of metal bar handles or retractable handles housed in the drawer front. The drawers are placed on various types of guides, ranging from simple, folded metal guides for drawers that hold lighter loads to slide-out telescopic guides for drawers able to hold heavier loads.
All of the drawers have catchment systems and brakes so that they go gently back into the closed position. They can be closed manually or automatically.