Abstract: A door closer components include a housing having a mounting plate, a tension member extending longitudinally within the central bore of the housing, a movable body within the housing connected to the tension member, a spring within the housing, and a hydraulic assembly for hydraulically controlling the longitudinal movement of the movable body. The hydraulic assembly is disposed within the central bore of the housing and includes a piston coupled to the housing and slidable in a fluid-filled chamber within the movable body, wherein the piston divides the chamber into two compartments. The piston has a valve mechanism which opens to permit relatively free movement of the fluid from one compartment to the other when the movable body is moved. The valve mechanism of the piston includes a boss fitted to a piston shaft and defining an annular sealing face and a longitudinally extending channel member integral with the boss.

Abstract: A door closer components include a housing having a mounting plate, a tension member extending longitudinally within the central bore of the housing, a movable body within the housing connected to the tension member, a spring within the housing, and a hydraulic assembly for hydraulically controlling the longitudinal movement of the movable body. The hydraulic assembly is disposed within the central bore of the housing and includes a piston coupled to the housing and slidable in a fluid-filled chamber within the movable body, wherein the piston divides the chamber into two compartments. The piston has a valve mechanism which opens to permit relatively free movement of the fluid from one compartment to the other when the movable body is moved. The valve mechanism of the piston includes a boss fitted to a piston shaft and defining an annular sealing face and a longitudinally extending channel member integral with the boss.