Apparatus for making profiled plastic tube

Claim 1

An apparatus for making a profiled tube by means of an extruder, said apparatus comprising two opposite endless chains, provided with driving means and circulating in horizontal planes, each chain making a plurality of molds or mold halves (18) moving along with the tube (2) produced by and coming from the extruder these molds or mold halves together constituting, in a rectilinear portion (32) of the paths (31) of said chains, a mold cavity in which the tube is being given its profile, wherein the chain comprises a plurality of links (1,2) interconnected by pivot pins (3), the driving means acting upon the links of the chain, each molds or mold halves (18) being supported by one link as to be movable relative to the associated links (1,2) in a direction perpendicular to the lengthwise direction of the chain or, in operation to the direction of movement (P) of the links, the machine frame being provided with guides (33, 35, 37) for the molds or mold halves, of which at least one straight guide (33) in the operative rectilinear portion (32) of the path, is located interiorly with respect to each chain loop and at least one curved guide (37) in each of the curved portions (36, 43) of each chain loop is located exteriorly with respect to the loop.

Claim 2

An apparatus for making a profiled tube by means of an extruder, said apparatus comprising two opposite endless chains, provided with driving means and circulating in horizontal planes, each chain making a plurality of molds or mold halves (18) moving along with the tube (2) produced by and coming from the extruder these molds or mold halves together constituting, in a rectilinear portion (32) of the paths (31) of said chains, a mold cavity in which the tube is being given its profile, wherein the chain comprises a plurality of links (1,2) interconnected by pivot pins (3), the driving means acting upon the links of the chain, each molds or mold halves (18) being supported by one link as to be movable relative to the associated links (1,2) in a direction perpendicular to the lengthwise direction of the chain or, in operation to the direction of movement (P) of the links, the machine frame being provided with guides (33, 35, 37) for the molds or mold halves, of which at least one straight guide (33) in the operative rectilinear portion (32) of the path, is located interiorly with respect to each chain loop and at least one curved guide (37) in each of the curved portions (36, 43) of each chain loop is located exteriorly with respect to the loop.

Claim 12

An apparatus for making profiled plastic tube by means of an extruder, said apparatus comprising two opposite circulating chains, each making a plurality of molds or mold halves (18) move along with the tube (2) produced by and coming from the extruder, these molds or mold halves together constituting, in a rectangular portion (32) of the paths (31) of said chains, a mold cavity in which the tube is being given its profile, wherein the molds (18) are arranged movably relative to the chain links (1,2) in a direction perpendicular to the direction of movement (P) of the links, the machine frame being provided with guides (33, 35, 37) for the molds, of which at least a guide (33) in the operative rectilinear portion (32) of the path, is located interiorly with respect to the chain loop and guides (37) in the curved portions (36, 43) of the path are located exteriorly with respect to the loop, said guides (37) for the molds, at the entrance and the exit end, at least at the location of a transition (38,42) to the operative portion (32) of the path, being situated more outwardly than those portions of the guides which lie at a greater distance from said operative portion of the path, said transitions at the entrance and the exit ends of the path (31) being bending points of mathematically calculated paths and the operative straight path tangentially joins said transitional portions (41,42), and braking means comprising sets of auxiliary toothed wheels (54,55) one (54) of which is mounted on a spindle of a driven toothed wheel at the entrance end, the other one (55) being an idle guiding wheel for the drive chain near the exit end, said auxiliary wheel (54) being fixedly mounted relative to the main drive wheel (40) and one of said auxiliary wheels (55) being rotatable over a certain angular distance relative to said main wheel (44), there being provided sets of springs (63) inbetween the two (44, 55) and a chain (56) being passed over the set of auxiliary toothed wheels (54, 55).

Claim 13

An apparatus for making profiled plastic tube by means of an extruder, said apparatus comprising two opposite circulating chains, each making a plurality of molds or mold halves (18) move along with the tube (2) produced by and coming from the extruder, these molds or mold halves together constituting, in a rectangular portion (32) of the paths (31) of said chains, a mold cavity in which the tube is being given its profile, wherein the molds (18) are arranged movably relative to the chain links (1,2) in a direction perpendicular to the direction of movement (P) of the links, the machine frame being provided with guides (33, 35, 37) for the molds, of which at least a guide (33) in the operative rectilinear portion (32) of the path, is located interiorly with respect to the chain loop and guides (37) in the curved portions (36, 43) of the path are located exteriorly with respect to the loop, said guides (37) for the molds, at the entrance and the exit end, at least at the location of a transition (38,42) to the operative portion (32) of the path, being situated more outwardly than those portions of the guides which lie at a greater distance from said operative portion of the path, said transitions at the entrance and the exit ends of the path (31) being bending points of mathematically calculated paths and the operative straight path tangentially joins said transitional portions (41,42), and braking means comprising sets of auxiliary toothed wheels (54,55) one (54) of which is mounted on a spindle of a driven toothed wheel at the entrance end, the other one (55) being an idle guiding wheel for the drive chain near the exit end, said auxiliary wheel (54) being fixedly mounted relative to the main drive wheel (40) and one of said auxiliary wheels (55) being rotatable over a certain angular distance relative to said main wheel (44), there being provided sets of springs (63) inbetween the two (44, 55) and a chain (56) being passed over the set of auxiliary toothed wheels (54, 55).