| 摘要 |
The valve housing 1 is provided with a so-called threaded housing ring 11. Between the wheel spindle 8 and the threaded housing ring 11 is an inner bush-type part 12 with an internal and external thread. The internal thread is arranged in such a way that it engages with the thread on the wheel spindle 8, the external thread entering into engagement with the thread on the threaded housing ring 11. During the first phase of the rotary motion of the wheel, the wheel spindle 8 screws into the internal thread in the inner bush-type part 12, after which it screws into the threaded housing ring 11 together with the inner bush-type part 12. The ratio of the pitch of the inner thread to that of the outer thread in the inner bush-type part 12 is such that the torque for opening is between 30% and 70% of the torque for closing. <IMAGE> |
