Damper device and hinge assembly including the same

A damper device comprising:

• an outer cylinder extending along a longitudinal axis;
• an inner cylinder which is disposed inside said outer cylinder to define a clearance between said inner and outer cylinders, and which defines therein an inner chamber for accommodation of a working fluid, said inner cylinder having a lower open end and an upper closed end wall formed with a vent hole;
• a piston disposed in said inner chamber to divide said inner chamber into an upper sub-chamber, which is in fluid communication with said clearance through said vent hole, and a lower sub-chamber, which is in fluid communication with said clearance through said lower open end, said piston having a passageway for fluid communication between said upper and lower sub-chambers, and being slidable between a distal position and a proximate position relative to said upper closed end wall;
• a check valve coupled to said passageway in a manner to permit a unidirectional flow of the working fluid from said lower sub-chamber to said upper sub-chamber such that when said piston slides toward the distal position, the working fluid is permitted to flow from said lower sub-chamber to said upper sub-chamber through said passageway, and such that when said piston slides toward the proximate position, the working fluid in said upper sub-chamber is forced to flow to said lower sub-chamber through said vent hole, said clearance, and said lower open end;
• and
• a piston rod having a lower rod end which is disposed outwardly of said outer cylinder, and an upper rod end which is mounted to said piston to permit said piston to slide with said piston rod such that sliding of the piston rod is dampened by sliding of said piston in said inner chamber, wherein said check valve includes
• a valve body,
• a valve seat formed on an upper side of said piston, and defining a valve hole in fluid communication with said passageway, said valve seat having a contour corresponding to a shape of said valve body, and
• a first biasing spring disposed between said valve body and said upper closed end wall to bias said valve body to couple on said valve seat so as to ensure the unidirectional flow of the working fluid from said lower sub-chamber to said upper sub-chamber.