ES312166A1 - Improvements in drag troweling arrangements for use in lining of conduits - Google Patents

Abstract

Apparatus for travelling coated interior surfaces of a pipe &c. 15, has a substantially frustoconical trowelling element 17 formed of one or more leaves, the longitudinal edges of which circumferentially slidably overlap, the larger end of the element being adapted to engage under pressure and to smooth the pipe coating, and a yieldable assembly for applying radially outward pressure to the interior surfaces of element 17 at locations around and within the trailing end thereof through anti-friction elements 31. The yieldable assembly may, as shown, consist of springs 21 mounted in spaced radical planes and anchored at their ends to spaced discs 22, 23. The latter are movable, on a central rod 24, relative to a fixed central member 25, by screws 26 rotated by handle 28 and such movement adjusts the pressure exerted on the element 17 by the anti-friction members 31. The forward end of element 17 is enclosed by housing 36 to prevent the ingress of foreign matter and has means for securing it to means for dragging the element through the pipe. In a further embodiment (Fig. 6, not shown) the leading end of the element 17 has support means which permit sliding of the element 17 relative thereto so as to constrict or expand the frustoconical element. With this embodiment the member 25 (Fig. 1) is adjustable along rod 24 so as to position the yieldable means in its optimum position. In a further embodiment the forward ends of springs 21 may be secured to the front housing 36.