| 主权项 |
1. An adjustable door closer comprising:
a hollow pedestal, comprising a first and a second chamber filled with lubricating oil as well as an actuating groove linked to the same side of the first and second chambers; of which, a partition wall is formed between the first and second chambers; an actuating device, set into the actuating groove of the hollow pedestal, comprising an actuating seat and a driving shaft; the driving shaft is provided with a driven end protruding out of the hollow pedestal, and the driving shaft is linked to a cam that can drive the actuating seat to generate translational movement during its rotation; a first piston assembly, set into the first chamber of the hollow pedestal, comprising a first piston head, a first link rod and a first spring; of which the first piston head could slide back and forth in the first chamber, the first link rod is used to link the first piston head and the actuating seat of the actuating device, and the first spring is assembled between the first piston head and a stopper surface of the actuating groove; an axial through-hole, formed axially onto the first piston head of the first piston assembly, such that the axial center of the first piston head allows for free flow of lubricating oil; a second piston assembly, set into the second chamber of the hollow pedestal, comprising a second piston head, a second link rod and a second spring; of which the second piston head could slide back and forth in the second chamber, the second link rod is used to link the second piston head and the actuating seat of the actuating device, and the second spring is assembled between the second piston head and the stopper surface of the actuating groove; moreover, a check valve is mounted onto one end of the second piston head, so as to control the flow of lubricating oil only from the actuating groove to the second chamber, or otherwise it is under a closed state; a laterally configured flow resistance unit, set onto the partition wall formed between the first and second chambers, comprising a primary and a secondary backflow channel set along the extended direction of the partition wall and also configured vertically at interval; of which both ends of the secondary backflow channel are closed, while one end of the primary backflow channel is closed, and the other end linked to the actuating groove; one side of the primary backflow channel is linked to the second chamber via a NO connecting hole, and one side of the secondary backflow channel is linked to the second chamber via the first and second backflow bypass holes; when the second piston head is not actuated, the second backflow bypass hole is blocked off; a first-section regulating valve, set onto the partition wall correspondingly to the primary and secondary backflow channels; and the regulating position of the first-section regulating valve is located between the primary backflow channel and the first backflow bypass hole of the secondary backflow channel; a second-section regulating valve, set onto the partition wall correspondingly to the primary and secondary back flow channels; and the regulating position of the second-section regulating valve is located between the primary backflow channel and the second backflow bypass hole of the secondary backflow channel. |
