| 摘要 |
A portable radio link system mast, particularly for use in the field, employing mast tube elements which are lifted, one after the other, by means of a lifting device installed in the head of the stand and, after a certain height is reached, are connected with always the next mast tube element. The lifting device consists of three frictionally self-locking pawls arranged on top of each other, a carrying pawl, a lowering pawl and a lifting pawl, which permit a slipless lifting, lowering and locking of the mast tube elements in connection with springs. A cardigan cam lever with a feeler stud draws attention to a wrong connection of the mast tube elements, and a mast tube element in the range of the lifting device can only be pushed out of the head of the stand after a correct contact is established with the following mast tube element.
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