MAINTAINABILITY DESIGN TECHNIQUES METRIC - AcqNotes.com

Downloaded from http://www.everyspec.com on 2011-10-29T14:56:01.DOD-HDBK-791(AM)4-3.3 OPENINGS FOR PHYSICAL ACCESSAccesses should be sized and shaped to permit easypassage of components; this feature is closely related tothe arrangement of components within the volume thatthe access is to accommodate (Fig. 4-5) (Ref. 3). If situationsand environmental factors dirt, danger from fallingobjects, climate– preclude an uncovered opening, ahinged door or sliding cover can be used (Figs. 4-1 and4-3); a hinged door is preferred to a cover plate. The hingeshould be supported at the bottom to remain open withoutmanual effort. If this is not feasible, then a catch orbracket– preferably automatic—should be used. Underno circumstances should it be necessary to hold a dooropen manually (Fig. 4-6) (Ref. 3).Figure 4-3. Sliding Access Door With Handle1. Optimize work space and tool clearance2. Reduce the need for the operator or technician tohandle fragile or sensitive items3. Facilitate the handling and or positioning ofheavy or awkward items4. Facilitate access to items that must frequently bemoved from the installed position for checking, servicing,or repairing.Figure 4-5. Example of Access to PermitEasy Removal of Component (Ref. 3)Figure 4-4. Examples of Rollout, Rotatable, and Slide-Out Drawers (Ref. 3)4-5