Apparatus for troweling plastic linings in conduits and the like

Claim 1

APPARATUS FOR TROWELING COATED INTERIOR SURFACES OF CONDUITS AND THE LIKE COMPRISING: A GENERALLY CONICALLY SHAPED ASSEMBLY FORMED OF A PLURALITY OF GENERALLY LONGITUDINALLY-EXTENDING SEGMENTS OF RESILIENT SHEET MATERIAL HAVING THEIR SIDE EDGES IN CIRCUMFERENTIALLY AND RELATIVELY SLIDABLE OVERLAPPING RELATION; MEANS AT THE SMALLER END OF THE ASSEMBLY FOR INDIVIDUALLY AND YIELDABLY MOUNTING EACH OF SAID SEGMENTS TO PERMIT THE TRAILING END PORTIONS OF THE ASSEMBLY TO EXPAND OR CONTRACT; A PLURALITY OF ELEMENTS LOCATED AT CIRCUMFERENTIALLY SPACED POINTS AROUND WITHIN THE TRAILING END OF THE ASSEMBLY FOR PRESSING AGAINST THE INTERIOR SURFACES THEREOF, SAID ELEMENTS BEING FREELY MOVABLE CIRCUMFERENTIALLY IN RESPECT TO THE INTERIOR SURFACES OF SAID SEGMENTS; AND MEANS CONTAINED WITHIN THE ASSEMBLY FOR INDIVIDUALLY AND YIELDABLY SUPPORTING SAID ELEMENTS AND DIRECTING SAME RADIALLY OF THE ASSEMBLY UNDER PRESSURE AGAINST SAID INTERIOR SURFACES, WHEREBY THE TRAILING END PORTIONS OF THE ASSEMBLY MAY RESILIENTLY BEAR AGAINST THE LINING MATERIAL AS THE ASSEMBLY IS ADVANCED ALONG WITHIN A CONDUIT AND WHILE PERMITTING THE AFORESAID EXPANSION OR CONTRACTION TO ACCOMMODATE VARIATIONS IN THE DIMENSIONS OF THE LINING.