Pneumatic door closer

• US 9,822,569 B2
• Filed: 07/15/2016
• Issued: 11/21/2017
• Est. Priority Date: 02/25/2016
• Status: Active Grant

• Current Assignee: Cmech Limited
• Original Assignee: Cmech Limited
• Inventors: Wang, Fan Shui
• Primary Examiner(s): O BRIEN, JEFFREY D
• Application Number:
  US15/211,098
• Publication Number:
  US 20170247922A1
• Time in Patent Office: 494 Days
• Field of Search: 16 66
• CPC Class Codes: E05F 1/1091 with a gas spring E05F1/1292 takes precedence
• CPC Class Codes: E05F 2003/228 Arrangements where the end of the closer arm is sliding in a track
• CPC Class Codes: E05F 3/02 with pneumatic piston brakes rotary type E05F3/14
• CPC Class Codes: E05F 3/104 with cam-and-slide transmission between driving shaft and piston within the closer housing
• CPC Class Codes: E05F 3/12 Special devices controlling the circulation of the liquid, e.g. valve arrangement E05F3/223 takes precedence; valves per se F16K
• CPC Class Codes: E05Y 2800/12 Sealing
• CPC Class Codes: E05Y 2900/132 Doors

Abstract

A pneumatic door closer includes a rotary energy-storing mechanism including a housing and a driving mechanism. The driving mechanism includes a cylinder, a second piston assembly and a sealing element, the sealing element is in an air tight connection with the cylinder and the second piston assembly, to form a closed space filled with high pressure gas in the cylinder. The second piston assembly drives the closed space into a first air chamber and a second air chamber in communication with each other. The driving mechanism also includes a first piston assembly connected to the second piston assembly. The pneumatic door closer also includes a transmission mechanism having one end received in the housing and another end connected to the door frame.

Claims

1. A pneumatic door closer, including:

a rotary energy-storing mechanism, including a housing and a driving mechanism connected thereto;

the driving mechanism includes a cylinder, a second piston assembly having one end configured within the cylinder, and a sealing element sleeving on the second piston assembly;

the sealing element is in an air tight connection with the cylinder and the second piston assembly, to form a closed space filled with high pressure gas in the cylinder;

the second piston assembly divides the closed space into a first air chamber and a second air chamber in communication with each other, the first air chamber is configured between the second piston assembly and the sealing element;

the driving mechanism further includes a first piston assembly configured in the housing, and the first piston assembly is connected to the other end of the second piston assembly;

the pneumatic door closer further includes a transmission mechanism having one end received in the housing and another end connected to a door frame;

when a door is opening via an external force, the transmission mechanism drives the first piston assembly to move toward the cylinder, and thus drives the second piston assembly to move away from the sealing element, squeezing the high pressure gas in the second air chamber, forcing the high pressure gas in the second air chamber to flow into the first air chamber, thereby the second air chamber will decrease in size;

when the external force applied on the door is removed, the second piston assembly moves toward the sealing element because a first action force, which is a pressure force exerted by a high pressure gas of the first air chamber onto the second piston assembly, is smaller than a second action force, which is a pressure force exerted by a high pressure gas of the second air chamber onto the second piston assembly, and the first action force is in a contrary direction to the second action force thereby the first air chamber decreases in size, and the high pressure gas in the first air chamber will flow into the second air chamber, to drive the first piston assembly away from the cylinder, whereby the transmission mechanism is driven to close the door.

2. The pneumatic door closer according to claim 1, wherein the second piston assembly includes a push rod and a fitting component configured on the push rod;

the fitting component is configured in the closed space, and contacts an inner wall of the cylinder to divide the closed space into the first air chamber and the second air chamber, in communication with each other, the first air chamber being close to the sealing element, and the second air chamber being away from the sealing element; and

the fitting component includes a throttle ring.

3. The pneumatic door closer according to claim 2, wherein the throttle ring is configured with an air inlet, an air outlet, a vent hole, and a throttle passage connecting the air outlet and the vent hole;

the fitting component further including a third sealing ring configured between the throttle ring and the inner wall of the cylinder;

when the door is opening, a gap appears between the fitting component and the inner wall of the cylinder, and the high pressure gas flows from the second air chamber into the first air chamber through the gap;

when the external force applied on the door is removed, the third sealing ring seals off the gap, thereby the high pressure gas flows through the air inlet, the air outlet, the throttle passage, and the vent hole, in turn, into the second air chamber.

4. The pneumatic door closer according to claim 3, wherein the fitting component includes a first gasket and a second gasket, the throttle ring is configured between the first gasket and the second gasket, and the fitting component further includes a nut used to fasten the first and second gaskets and the throttle ring to the push rod.

5. The pneumatic door closer according to claim 1, wherein a through-hole is configured in the sealing element, the second piston assembly including a push rod and a fitting component configured thereon, and the push rod extends through the through-hole to connect to the first piston assembly.

6. The pneumatic door closer according to claim 5, wherein one end of the sealing element is threadably connected to the housing, and the other end is configured within the cylinder and is in air tight sealing connection with the cylinder;

and a first groove and a second groove are configured on the other end of the sealing element.

7. The pneumatic door closer according to claim 6, wherein a first sealing ring is configured within the first groove to seal off a joint between the inner wall of the cylinder and the sealing element;

and a second sealing ring is configured within the second groove to seal off a joint between the push rod and the sealing element.

8. The pneumatic door closer according to claim 2, wherein the first piston assembly includes a piston body and a wheel configured thereon, and a recess is provided on the piston body to receive the push rod.

9. The pneumatic door closer according to claim 8, wherein the transmission mechanism includes a cam configured within the housing and a rod connected to the cam, and the cam being connected to the wheel.

10. The pneumatic door closer according to claim 9, wherein a sliding rail mechanism connected to the rod is provided at the door frame.