A device for driving a hose or cable reel along a feed beam of a drilling machine at half the speed of the drilling machine. The device comprises a slide guided by the feed beam in which a sprocket wheel is journalled in the slide and is rotated by engagement with the drive chain or similar drive means for the drilling machine to move back and forth in engagement with a stationary member on the feed beam at half the speed of the drilling machine.
A safety device for a drilling rig of the type wherein a drill-carrying cradle is caused to move upwardly or downwardly on a tower by a chain which traverses sprockets at opposite ends of the tower. Shock loads and vibration cause premature failures in the chain when withdrawing a drill string as the cradle is pulled upwardly on the tower. The present invention minimizes shock loads on the chain to minimize the possibility of a chain failure and, at the same time, prevents a fall of the cradle and drill carried thereby if the chain above it should break, this latter function being accomplished with the use of spring-loaded toothed dogs on the cradle which engage the tower and prevent movement of the cradle in the event of a chain failure.
An earth drilling method and apparatus utilizes a unique drill string rotary drive and support arrangement which provides for the utilization of longer drill strings than could heretofore be accommodated on prior art drill masts of equal height.
