Hydraulic door closer
AssigneeSam Kyong Hardware Co., Ltd.
InventorsSun O. Nam, Wan S. Lee, Jae Y. Yoo
Life of this patent
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Abstract
A new type of hydraulic door closer is disclosed. The device of the present invention utilizes spring force and hydraulic pressure, and is equipped with a straightly extending arm instead of the conventional type of the folding arms. The advantages of the device of the present invention are that variations of the size of the device are not required for different sizes and weights of doors, and the lack of the folding portion of the arm enables avoiding of wear and stress on the critical parts. Another advantage of the device of the present invention is that different door opening ranges are provided such as 80 degrees, 90 degrees and 100 degrees in addition to a free moving zone.
Claims4
A hydraulic door closer comprising:
- a cam installed in a groove;
- two annular protrusions formed at a front end portion of a piston rod, for engagement with the cam;
- a first hydraulic passage having a middle auxiliary passage, provided under an oil cylinder within a main body of the closer;
- a check valve provided at a front of an auxiliary passage;
- an orientation valve;
- three small passages closed or opened by the orientation valve;
- and
- a second hydraulic passage installed beside the first hydraulic passage in such a manner that the first and second hydraulic passages can be opened or closed according to a position of a moving attached to other end of said piston rod to regulate the flow rate of hydraulic fluid, for ultimately regulating the speed of a closing door.
Dependencies are inferred from the claim text.