{HEAD ~ The linkage mechanism} allows {TAIL ~ the door} to move between a closed position where the door is placed against the housing and in front of the opening to prevent access therethrough, and an opened position where the door is placed away from the opening to allow access therethrough 
{ HEAD ~ The linkage mechanism } allows { TAIL ~ the door } to move between a closed position where the door is placed against the housing and in front of the opening to prevent access therethrough , and an opened position where the door is placed away from the opening to allow access therethrough
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