"There is practically no chance communications space satellites will be used to provide better telephone, telegraph, television, or radio service inside the United States."
|3976149||Rock drill equipment having a mechanized drill bit exchange|
At a rock drill, preferably most forwardly on its frame, a magazine with drill bits is arranged. When a drill bit has been worn such that it must be exchanged, the drill rod is retracted so much that the worn drill bit arrives at the magazine. By special ...