Braking apparatus for closure members

A braking apparatus for a closure member, the braking apparatus comprising:

• a main body for connection to one of a frame and a closure member mounted on the frame to undergo linear reciprocating movement between open and closed positions of the closure member, the main body having an interior space containing a braking fluid;
• a hollow shaft mounted in the main body for undergoing rotation;
• a resistance member disposed in the interior space of the main body containing the braking fluid and mounted on an outer periphery of the hollow shaft for rotation therewith;
• and
• a spiral rod for connection to the other of the frame and the closure member, the spiral rod being screw-threadably engaged with an inner surface of the hollow shaft so that the hollow shaft undergoes rotation when the spiral rod and the hollow shaft are relatively moved in an axial direction of the spiral rod;
• wherein when the closure member undergoes linear reciprocating movement between the open and closed positions, the main body or spiral rod relatively moves in the axial direction of the spiral rod, the hollow shaft undergoes rotational movement together with the resistance member, and the resistance member receives a resistance of the braking fluid so that the hollow shaft rotates under a braking force of the braking fluid and reduces a movement speed of the closure member.