| 摘要 |
A ball-type sealing device is disclosed for preventing fluid flow out of an orifice wherein the sealing ball is mounted in a body member so as to have both radial or transverse and axial degrees of freedom. The sealing ball, which has a diameter greater than that of the orifice, is mounted in a chamber defined by the body member such that a portion of the ball extends through an aperture in the end of the chamber to the exterior of the body member. The sealing ball is positioned by a pushrod slidably extending into an elongated hole defined by the body member such that one end of the pushrod, having a first contact surface S1, is in contact with the sealing ball. The opposite end of the pushrod is associated with a second contact surface S2 which has an area smaller than the contact surface S1. The sealing ball may be accurately placed in the orifice to be sealed since it has both a transverse degree of freedom, due to the diameter of the chamber in the body member being larger than the diameter of the sealing ball, as well as an axial degree of freedom. Pressure exerted on the sealing ball along the longitudinal axis of the body member exerts a force on the pushrod which, in turn, causes permanent axial deformation of a crush portion of the body member adjacent to the second end of the pushrod. This deformation provides the necessary axial play or clearance between the pushor and the ball.
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