Apparatus for applying a plastic film wrapping to a pipe line

Claim 1

APPARATUS FOR APPLYING SINGLE THICKNESS HEAT SHRINKABLE SYNTHETIC RESIN FILM TO THE OUTSIDE SURFACE OF A RIGID PIPE COMPRISING: A SUPPORT FRAME; MEANS ASSOCIATED WITH SAID FRAME TO SELF-PROPEL AND GUIDE SAID FRAME RELATIVE TO SAID PIPE IN A FORWARD DIRECTION; A WING SHAPED FILM HOLDER HAVING A LONGITUDINAL OPENING TO PERMIT AXIAL MOVEMENT OF SID PIPE AND SUPPORTED TO SAID FRAME, THE FORWARD ROUNDED EDGE OF SAID FOLDER EXTENDING OUTWARDLY AND REARWARDLY FROM SAID OPENING, THE UPPER SURFACE SMOOTHLY TAPERED DOWNWARDLY AND FORWARDLY TO SAID FORWARD EDGE, THE LOWER SURFACE SMOOTHLY ROUNDED UPWARDLY AND FORWARDLY TO SAID FORWARD EDGE; A SUBSTANTIALLY TUBULAR PORTION COAXIALLY EXTENDING ABOUT SAID PIPE REARWARDLY FROM SAID FOLDER AND HAVING LONGITUDINAL OVERLAPPING SPLIT LEAVES ALONG ITS UPPER SURFACE, SAID LEAVES SPRING-FLEXIBLE TO PERMIT EXPANSION AND CONTRACTION OF SAID LEAVES; A SUPPLY ROLL OF SAID FILM FOTATABLY SUPPORTED ABOUT AN AXIS ON SAID FRAME NORMAL TO THE AXIS OF SAID PIPE; MEANS TO TENSION AND GUIDE SAID FILM FROM SAID ROLL TO SID FORWARD EDGE JOF SAID FOLDER ALONG SAID LOWER SURFACE, THENCE REARWARDLY ALONG SAID UPPER SURFACE AND SAID OPENING TO FORM A FOLD REARWARDLY THEREOF ABOUT SAID PIPE SUCH THAT ONE LONGITUDINAL EDGE OF SAID FILM IS BETWEEN SAID PIPE AND ONE LEAF OF SAID TUBULAR MEMBER, WHILE THE OTHER LONGITUDINAL EDGE OVERLAPS SAID ONE EDGE BETWEEN SAID LEAVES TO FORM A CONTINUOUS LONGITUDINAL SEAM REARWARDLY THEREOF; AND MEANS TO JOIN SAID SEAM AND HEAT SAID FILM WHEREBY AFTER COOLING SID FILM WILL SHRINK TIGHT UPON SAID PIPE.