Abstract: The present invention provides an adjustable hinged door closer, including a seat with the first and second cylinders, and a first and a second elastic linkage unit. A double-threaded regulator is incorporated onto the first connecting rod of the first elastic linkage unit, so as to change the compression of the spring and regulate the closing/restoring force of the door body. The double-threaded column of the double-threaded regulator has a double-thread that shifts to two thread pitches by just making one rotation, thus facilitating the fine-tuning easily. The elastic linkage unit and the regulator are structurally configured to be assembled externally, and then mated with the connecting seat of the door closer.

Abstract: The present invention provides an adjustable hinged door closer, including a seat with the first and second cylinders, and a first and a second elastic linkage unit. A double-threaded regulator is incorporated onto the first connecting rod of the first elastic linkage unit, so as to change the compression of the spring and regulate the closing/restoring force of the door body. The double-threaded column of the double-threaded regulator has a double-thread that shifts to two thread pitches by just making one rotation, thus facilitating the fine-tuning easily. The elastic linkage unit and the regulator are structurally configured to be assembled externally, and then mated with the connecting seat of the door closer.

Abstract: A door closer includes a casing having a hydraulic cylinder in which a coupling block is received, and a first tunnel and a second tunnel are in communication with the hydraulic cylinder. A passage is in communication between the first and second tunnels so as to allow the hydraulic oil to flow between the two tunnels. The coupling block includes a pivot shaft for being connected to a door. A first rod and a second rod are pivotably connected to the coupling block and respectively inserted in the first and second tunnels. A threaded rod is connected to a distal end of the first rod and a first spring is mounted to the first rod and the threaded rod. A sleeve is threadedly engaged with the threaded rod and an operation rod is securely connected to the sleeve so that when rotating the operation rod, the first spring is adjusted by moving the sleeve relative to the threaded rod.

Abstract: A door closer includes casing fixedly fastened to a door frame, a hydraulic cylinder installed in the casing and holding a hydraulic fluid, a coupling block installed in one end of the hydraulic cylinder, the coupling block having a pivot shaft connected to a door, and a reciprocating mechanism coupled to the coupling block, fluid velocity regulating valves installed in the casing and controlled to adjust the velocity of the hydraulic fluid flowing in the casing, the reciprocating mechanism including a double-threaded adjustment rod for adjusting the spring power of compression springs thereof.