Door closer with reduced return reaction force

Abstract

A pneumatic rod with reduced return reaction force comprises: an outer tube with a valve seat tightly fitted at its first end, the valve seat having a first air hole, and a stop seat tightly fitted at the second end of the outer tube, the stop seat having a sliding cavity axially inserted in its center; a rod body slidingly placed in the sliding cavity of the stop seat, the first end of the rod body having a piston portion that is tightly fitted with the inner wall of the outer tube, and the second end of the rod body extending out of the stop seat; and a return spring installed inside the outer tube, which elastically drives the rod body to move towards the valve seat under normal conditions; wherein the outer tube wall has at least one pressure relief chamber, the length of the pressure relief chamber being greater than the width of the piston portion, and the inner diameter of the outer tube located at the pressure relief chamber being greater than the diameter of the piston portion.

Claims

1. A pneumatic rod for mitigating return reaction force, comprising: An outer tube has a valve seat tightly fitted at its first end, the valve seat having a first vent hole, and a stop seat at the second end of the outer tube having a sliding cavity; a rod is slidably placed in the sliding cavity, with a piston portion at the first end of the rod and the second end of the rod extending out of the stop seat; and a return spring is installed inside the outer tube, which elastically drives the rod to move towards the valve seat under normal conditions; wherein at least one pressure relief chamber is provided on the inner wall of the outer tube, the length of the pressure relief chamber is greater than the width of the piston portion, and the inner diameter of the outer tube at the pressure relief chamber is greater than the diameter of the piston portion.

2. The pneumatic rod with reduced return reaction force as described in claim 1, wherein the outer tube has a length of l, and the pressure relief chamber is located at a position of l / 2 to l / 10 of the total length of the outer tube from the first end of the outer tube.

3. The pneumatic rod with reduced return reaction force as described in claim 1, wherein each of the pressure relief chambers is formed by the inner wall of the outer tube protruding outward.

4. The pneumatic rod with reduced return reaction force as described in claim 1, wherein each of the pressure relief chambers is formed by a spiral groove formed on the inner wall of the outer tube.

5. The pneumatic rod with reduced return reaction force as described in claim 1, wherein the pressure relief chamber is axially parallel to the outer tube.

6. The pneumatic rod with reduced return reaction force as described in claim 1, wherein the valve seat is further provided with a second air hole, which is normally covered by a valve plate, so that when the rod moves away from the valve seat, the valve plate can be opened by drawing in air.

7. The pneumatic rod with reduced return reaction force as described in claim 1, wherein the rod system is a hollow rod, and an axial hole is provided in the piston part provided at the first end of the rod body. A stop member is fixed at the second end of the rod body, and the stop member is provided with a through hole to slide a rod member inside, such that the first end of the rod member is fixed to a piston seat that is tightly fitted to the inner wall of the rod body, and the outer diameter of the piston seat is larger than the inner diameter of the through hole and larger than the diameter of the hole in the piston part, and the return spring is located between the rod member and the valve seat.

8. The pneumatic rod with reduced return reaction force as described in claim 1, wherein an elastic member is disposed between the rod and the valve seat.

9. The pneumatic rod for mitigating return reaction force as described in claim 7, wherein an elastic member is disposed between the piston seat and the piston portion.

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