A hinge assembly with means for attachment between a door and a door frame, said assembly containing damper means comprising:
- a first body of cylindrical shape;
- an axial shaft passing through said first body;
- a coiled spring surrounding said axial shaft and generally attached to said first body;
- a second body of cylindrical shape having a first end and a second end opposite said first end, said second body axially and rotatably anchored at said first end on said first body;
- a hydraulic chamber for containing a hydraulic fluid, said chamber being positioned in said second body, said hydraulic chamber comprising a first closure cap disposed inside said second cylindrical body close to said first end, said first closure cap defining a first central perforation in its surface through which said axial shaft passes;
- and a second closure cap disposed inside said second cylindrical body near said second end;
- and
- piston means associated with said chamber and comprising a section slidably held within said chamber and a spindle generally attached to said axial shaft and threadably received in said section, said section defining at least one inlet hole in its surface such that the automatic closing motion of the door is dampered by the turning of said first body resulting in the decompression of said spring causing said axial shaft and therefore said spindle to turn this resulting in said section axially moving along the length of said chamber while being resisted by said hydraulic fluid, said hydraulic fluid passing through said inlet hole, said spindle comprising an axial retention ring rotatably mounted on said axial shaft where said shaft passes through said first central perforation of said first closure cap such that said ring acts as a pivot for said rotation of said first cylindrical body, at least one coupling mounted on said axial shaft next to said retention ring;
- at least one longitudinal guide located between said section and the interior of said second cylyndrical body, such that said longitudinal guide hinders rotation of said section,
- said piston means further comprising at least one, unidirectional outlet bypass valve comprised of a ball and a generally open housing, such that during the opening motion of the door, said coiled spring is compressed forcing said shaft to turn and therefore said section to ascend and displace said hydraulic fluid by forcing it to pass through said outlet bypass valve;
- and
- a cylindrical bushing mounted on said axial shaft and providing anchoring means for said cylindrical bodies, said assembly, said cylindrical bushing facilitating oil tightness of said hinge assembly, complementing axial retention of said ring and providing anchoring means for said coiled spring surrounding said axial shaft by means of welding.