Pipe straightening and spinning method and apparatus
AssigneeEnglish Clays Lovering Pochin & Company Limited
InventorRoyston Paul Jenkin
Life of this patent
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Abstract
A method and apparatus for temporarily straightening and spinning of pipes wherein at least three sets of rollers are used, each set including four rollers of which two are rotatably mounted in fixed locations and the other two of which are movable by hydraulic driving means, one or more of the fixed location rollers being drivable; collars, each made of three hinged segments, are used around the pipe, which collars are circumferentially stronger than the pipe wall; by pressing the movable rollers against the collars, the collars are held closed and the pipe is held straight while being spun. The invention is particularly although not exclusively applicable for use in a process of lining of pipes.
Claims18
A method of temporarily straightening and spinning a non-straight pipe comprising providing a plurality of removable circular collars axially spaced along the pipe, which collars circumferentially closely surround the pipe and have a higher yield strength in the circumferential direction than that of the pipe wall, each collar being formed of three segments of approximately equal arcuate length and two of the segments being hingedly connected to respective opposite ends of the third segment so as to allow the segments to be pivoted relative to each other to open the collar for positioning the collar around the pipe, applying forces to the collars by means of roller elements in directions so as to straighten the pipe and to hold it substantially straight during rotation, and rotating the collars and the pipe.
Pipe straightening and spinning apparatus comprising at least three sets of rollers, the axes of all the rollers being parallel and each set comprising four rollers arranged for acting at approximately equally spaced circumferential positions relative to a pipe located between them, the sets of rollers being spaced from each other in the axial direction so as to act at predetermined positions along the pipe length, two rollers of each set being rotatably mounted in bearings fixed to a rigid frame and the other two rollers of each set being rotatably mounted and reciprocably movable in directions perpendicular to the axes of the said other two rollers and generally towards or away from the axis of a pipe when located between the rollers, there being provided a plurality of collars, one for each set of rollers, to be positioned around a pipe at axial spacings along the pipe corresponding to the axial positions of the roller sets and which collars are adapted to closely surround the pipe and to have a higher yield strength in the circumferential direction than that of the pipe wall, each collar being formed of three segments of approximately equal arcuate length and two of the segments being hingedly connected to respective opposite ends of the third segment so as to allow the segments to be pivoted relative to each other to open the collar for positioning the collar around the pipe, hydraulic driving means for moving each movable roller of each set into contact with the respective collars to hold the collars in a closed condition around the pipe by roller contact and for applying pressure against the respective collars thereby to hold the pipe temporarily straight, and means for drivingly rotating one or more of the fixed-position rollers for spinning the pipe.
Dependencies are inferred from the claim text.