| 摘要 |
The invention relates to an extension joint for concrete poles of the type in which at least one pin in a first pole penetrates into a recess in a second pole. The end of the pin is provided with a shoulder and is locked in the second pole by means of a wedge having shanks each engaging one side of the pin. The wedge is locked in its driven-in position while being driven in by the bending of the shanks towards each other after they have passed the pin. The wedge and the free end of the pin are covered by a channel member or furrow, whose side walls have portions bent inwards and guiding the shanks when the wedge is being driven in. |
