Pipe welding tool carriage

Claim 1

IN COMBINATION, FIRST MEANS DEFINING A GENERALLY CYLINDRICAL MOUNTING BAND, CLAMP MEANS CARRIED BY SAID BAND AND ADAPTED TO CLAMPINGLY MOUNT SAID BAND ON A PIPE OF SMALLER DIAMETER THAN SAID BAND AND WITH THE LATTER GENERALLY CONCENTRICLLY DISPOSED ABOUT SAID PIPE AND SPACED THEREFROM, AN ELONGATED TOOL CARRIAGE EXTENDING TRANSVERSELY OF SAID BAND, FIRST ROLLER MEANS CARRIED BY ONE END PORTION OF SAID CARRIAGE AND SECOND ROLLER MEANS CARRIED BY THE OPPOSITE END PORTION OF SAID CARRIAGE AND JOURNALLED FOR ROTATION ABOUT AXES GENERALLY PARALLELING THE BAND AXIS AND DISPOSED IN ROLLING CONTACTING RELATION WITH CIRCUMFERENTIALLY SPACED PORTIONS OF THE INNER SURFACES OF SAID BAND, ADDITIONAL ROLLER MEANS CARRIED BY SAID CARRIAGE AND JOURNALLED FOR ROTATION ABOUT AN AXIS GENERALLY PARALLELING AND DISPOSED BETWEEN RADIAL PLANES OF SAID BAND CONTAINING SAID AXES AND DISPOSED RADIALLY OUTWARDLY OF THE PLANE IN WICH SAID AXES LIE, SAID ADDITIONAL ROLLER MEANS BEING ADAPTED TO BE DRIVINGLY CONNECTED TO A SOURCE OF MOTIVE POWER AND DISPOSED IN ROLLING AND DRIVING FRICTIONAL ENGAGEMENT WITH THE OUTER SURFACE OF SAID BAND, AND SAID CARRIAGE BEING ADAPTED TO CARRY A TOOL FOR WORK ON THE PIPE DURING ITS MOVEMENT THEREABOUT.