| 摘要 |
A hydraulic door closer including an elongated housing, a connection rod extending into the housing, a piston secured at an inner end of the connection rod within the housing and a spring positioned within the housing about the connection rod. A throttle valve and a check valve are formed in the piston and define a throttle-valve fluid passage and a check-valve fluid passage, respectively. Both fluid passages are configured to be open for passing a fluid through the valves and closed to stop the fluid flow. The check-valve fluid passage is larger than the throttle-valve fluid passage and is closed during door closing for restricted fluid flow slowing the door motion. A stopping/holding mechanism includes a piston groove, a rod groove and a positioning pin disposed between the piston and the connection rod. The piston groove is defined by the piston for retaining the entire positioning pin during door opening/closing motion. The rod groove is defined by the connection rod to receive a portion of the positioning pin when both grooves are moved into alignment to close both valves and block the fluid flow between the chambers to hold the door open. |
