Anti Slam Door Closer

In a hospital, the bang wakes patients. In a school, it scares children. In a library, it annoys everyone. And over time, the banging loosens the door frame. It cracks the wall. It can even pinch fingers.

This anti slam door closer has a long slow down. 60 degrees of slow down. From the time the door is fully open at 90 degrees, 60 of those degrees are slow. Only the first 30 degrees are free. Normal closers only have slow down for the last 10-15 degrees. The rest is free and fast.

The final anti slam angle is 25 degrees. That is the key number. When the door is 25 degrees away from the frame, the closer does a second slow down. The final closing force is 150N or less. That is about 15kg of force. A normal closer has a final force of 300-500N. So our anti slam door closer reduces the slam force by 50-70%.

This closer is size 2 or 3. Size 2 for doors 40-65kg. Size 3 for doors 65-85kg. These are interior wooden doors, office doors, and classroom doors. This is not for heavy doors. If you put this on a 150kg steel door, it will break.

The arm is thicker than normal. 4.0mm steel plate. Normal arms are 2.5-3.0mm. The anti slam action puts more stress on the arm. So we made it thicker. It will not bend.

Because the design goal is to protect the door frame, the wall, and fingers. A hospital installed this anti slam door closer on a patient room door. The nurse said the door used to go "BANG" and the patient would jump. Now the door goes "puff". You barely hear it. The hospital ordered 200 more.

This closer is for hospitals, nursing homes, kindergartens, school classrooms, libraries, and any place where quiet and safety matter.