| 摘要 |
<p>A valve closure is disclosed which comprises a bifurcated arm 14 pivotally coupled to a sleeve 34 by a connector 28 and a pivot pin 26. The sleeve 34 receives a rod 44 coupled to a base plate 46 for receiving a spring 42. The sleeve 34 also has a support plate 38 coupled thereto which receives the spring 42. When the valve element is in an open position the arm 14, sleeve 34 and rod 44 are a generally straight line so that the spring does not exert any torque on the valve element. However, when the valve element commences to close the arm 14 is moved relative to the sleeve 34 and the rod 44 so that the spring 42 causes torque to be exerted through the arm to assist closure of the valve element. In a second embodiment a tension spring 104 is provided which acts on lever 106 pivotally connected to a closure arm 108.</p> |
