Forming apparatus for synthetic-material tubes
OwnerArne Johanssoninventor
Life of this patent
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Abstract
A forming apparatus comprising mold parts adapted to fit inside a tube to shape a groove or other profile therein. The parts are segments of the periphery arranged in at least two groups, such that the parts of one group alternate with the parts of the other group. The first group of parts is undercut to provide pockets in which the second group may rest when the mold parts are retracted. The first group is extended first, leaving spaces therebetween which are filled by the second group when they are extended. A mechanical actuation of the parts is disclosed in one embodiment and fluid-actuation is disclosed in a second embodiment.
Claims13
For shaping the inner surface of tubes of deformable material, forming apparatus disposed within the tube, with its middle axis on the longitudinal axis of said tube including means to soften the tube in the region where forming is to occur, and at least one shaping element forcing radially outward a portion of the tube to produce an inner profile, which element is provided with a number of mold segments disposed end-to-end about the periphery of said element in a common plane radial to said tube axis and which are radially extendable and retractable, said segments being divided into at least two groups, a mold segment belonging to the one group being disposed between segments belonging to at least one other group, the segments of the one group at their opposite ends having offset portions toward the central axis to provide a pocket which, when the shaping element is contracted, receives the mold segment of the other group, a guide plate for each group of segments, each said guide plate being displaceable axially of said tube to effect movement of actuating rods which effects radial displacement of the segments in the group.
For shaping the inner surface of tubes of deformable material, forming apparatus disposed within the tube with its middle axis on the longitudinal axis of said tube, including means to soften the tube in the region where forming is to occur and at least one shaping element forcing radially outward a portion of the tube to produce an inner profile, which element is provided with a core and a number of mold segments disposed end-to-end about the periphery of said element in a common plane radial to said tube axis and which are radially extendable and retractable, said segments being divided into at least two groups, the mold segments belonging to one group being disposed between segments belonging to at least one other group, the segments of one group at their oppposite ends having offset portions toward the central axis to provide a pocket which, when the shaping element is contracted, receives the mold segment of the other group, each segment having a cylindrical bore disposed radial to said axis, the core of said element having in said common radial plane a piston for each of said mold segments, the piston for one group having channels communicating with a supply of pressure medium and the piston for the other group having channels for separate communication with a source of pressure medium whereby said separate communication of pressure medium may introduce pressure medium into said cylinders of the one group independently of the cylinders of the other group and effect independent radial displacement of the respective groups of segments.
Dependencies are inferred from the claim text.