A normally open fire door closer

Abstract

The invention discloses a door closer for a normally open fireproof door. The key point of the technical scheme is that the vertical plate on the installation frame is hinged with the pawl, the pawl is connected with a transmission mechanism, and a control mechanism is arranged above the transmission mechanism. One end of the pull rod is hinged with the pawl, and the other end is covered with a compression spring, one end of the compression spring is in contact with the pull rod, and the other end is in conflict with the spring holder; one end of the swing rod extends upward to form a swing part, so A return spring is provided between the swing part and the control mechanism. When the control mechanism drives the swing rod to swing, the fastening part of the swing rod swings downward and escapes from the notch, and the pull rod will slide forward under the action of the compression spring, thereby Drive the ratchet to rotate relative to the vertical plate and separate from the ratchet, the elastic potential energy of the compression spring of the present invention is directly transmitted to the ratchet only through a part of the pull rod, which improves the conversion efficiency of the elastic potential energy of the compression spring, has a simple structure, reduces manufacturing costs, and also Easy to operate.

Description

technical field [0001] The invention relates to the field of door closers, more specifically, it relates to a normally open fire door closer. Background technique [0002] At present, the existing door closers are normally closed door devices, which are mainly installed on the fire doors that are closed all the year round, and keep the fire doors closed at any time to prevent the fire from spreading through the fire doors when a fire occurs. It is more practical on fire doors with small traffic; however, in public buildings with relatively large flow of people or goods, this kind of door closer often cannot meet the practical requirements. Because people or goods need to pass through the fire doors frequently, people need a lot of time and effort. Opening the fire door by physical force greatly affects the convenience of people passing through. If the fire door is fixed in the open state with tools, the fire will spread quickly through the fire door to the surroundings if th...

AI Technical Summary

Problems solved by technology

[0005] When the connecting rod moves to the right under the action of the elastic potential energy of the return spring, the connecting rod needs to drive the crank to move to the right to drive the pawl to open a certain angle. Since the elastic potential energy of the return spring needs to be transmitted through the connecting rod and the crank, the structure of the transmission mechanism is complicated. , will reduce the transmission efficiency of the elastic potential energy of the return spring, which requires higher requirements for the return spring. If the elasticity of the return spring is insufficient, it will not be able to drive the pawl to open a certain angle. At the same time, the connecting rod and the crank are hinged, and the two are prone to occur. Stuck phenomenon, resulting in the inability to normally drive the pawl to open a certain angle, which is not easy to operate

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