Roll grooving apparatus

In roll grooving apparatus comprising a grooving roll and a back-up roll, means supporting said grooving roll and said back-up roll for rotation respectively about a first axis and a second axis, and means for relatively displacing said grooving and back-up rolls radially toward and away from one another, said grooving roll having a circumferentially extending rolling projection and said back-up roll having an outer surface including a circumferentially extending rolling groove, the improvement comprising:

• said outer surface of said back-up roll including tooth means on the axially outer and inner sides of said groove for biasing said back-up roll and a pipe being grooved axially inwardly relative to one another in response to relative rotation between said back-up and grooving rolls and a pipe therebetween, the tooth means on the axially inner side of said groove having a first axial length, and the tooth means on the axially outer side of said groove having a second axial length less than said first axial length.

A back-up roll for use in rolling a groove in a pipe having an axis, said back-up roll having an axis of rotation and an outer surface extending circumferentially about said axis of rotation and having axially outer and inner ends, said outer surface including a first portion providing a rolling groove between said ends, a second portion between said rolling groove and said inner end and a third portion between said rolling groove and said outer end, said second and third portions including tooth means for rotatably engaging a pipe during rolling of a groove therein, and the tooth means on said second portion being axially wider than the tooth means on said third portion.

A grooving roll for use in rolling a groove in a pipe having an axis, said grooving roll having an axis of rotation and an outer surface extending circumferentially about said axis of rotation and having axially outer and inner ends, said outer surface including a radially outwardly projecting circumferentially extending rolling projection between said ends, said projection having an outer rolling surface having axially outer and inner ends, said rolling surface having a taper between the outer and inner ends thereof for biasing a pipe being grooved and said grooving roll axially inwardly relative to one another during the rolling of a groove in the pipe.

In roll grooving apparatus comprising a grooving roll and a drive roll, means supporting said grooving roll and said drive roll for rotation respectively about a first axis and a second axis, drive means for rotating said drive roll about said second axis, and means for relatively displacing said grooving roll and said drive roll radially toward and away from one another, said grooving roll having a circumferentially extending rolling projection and said drive roll having an axially outer end and a circumferentially extending rolling groove, the improvement comprising:

• said means supporting said grooving roll and said drive roll including means supporting said outer end of said drive roll for rotation about said second axis.

Roll grooving apparatus for rolling a groove in a pipe comprising, a drive roll, first support means supporting said drive roll for rotation about a drive roll axis, second support means mounted on said first support means for pivotal displacement about a pivot axis parallel to said drive roll axis, a grooving roll mounted on said second support means for rotation about a grooving roll axis, a feed screw member having a feed screw axis and axially opposite first and second ends respectively interengaged with said first and second support means for rotation of said screw member about said feed screw axis to displace said second support means and said grooving roll thereon about said pivot axis to displace said grooving roll radially toward and away from said drive roll, said second end of said screw member including means by which said screw member can be rotated, and said feed screw axis being inclined relative to a plane through said drive roll axis and said grooving roll axis such that said second end of said screw member is closer to said plane than said first end.

Roll grooving apparatus for rolling a groove in a pipe comprising, a drive roll, first support means supporting said drive roll for rotation about a drive roll axis, second support means mounted on said first support means for pivotal displacement about a pivot axis parallel to said drive roll axis, a grooving roll mounted on said second support means for rotation about a grooving roll axis, feed screw means between said first and second support means for displacing said second support means and said grooving roll thereon about said pivot axis to displace said grooving roll radially toward and away from said drive roll, said feed screw means including a feed screw member having a feed screw axis and axially opposite first and second ends, said first end being threaded and in threaded interengagement with said first support means, said second end being cylindrical and interengaged with said second support means for rotation relative thereto about said feed screw axis and for sliding displacement of said second support means axially of said second end in the direction toward said first end, and means releasably interengaging said second end and said second support means against axial displacement in said direction.

Roll grooving apparatus for rolling a groove in a pipe comprising, a back-up roll, first support means supporting said back-up roll for rotation about a back-up roll axis, a grooving roll, second support means supporting said grooving roll for rotation about a grooving roll axis, means interconnecting said first and second support means for displacement relative to one another to displace said back-up roll and said grooving roll radially toward and away from one another, said back-up roll having a radially outer surface including a circumferentially extending rolling groove and tooth means on the axially outer and inner sides of said groove, the tooth means on the inner side of said groove having an axial length greater than that of the tooth means on the outer side of said groove, said grooving roll having a circumferentially extending rolling projection, and said grooving roll being supported on said second support memo for said grooving roll axis to be at an angle with respect to said back-up roll axis.