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An apparatus for cold rolling a piping element connection with multiple outward steps has first and second rollers, a driver for the second roller, and a positioning roller. The first roller rotates about a first axis, with first and second upper surfaces of rotation centered thereabout, the first s

An apparatus for cold rolling a piping element connection with multiple outward steps has first and second rollers, a driver for the second roller, and a positioning roller. The first roller rotates about a first axis, with first and second upper surfaces of rotation centered thereabout, the first surface mean diameter being less than that of the second surface. The first roller has an upper leading edge between the first and second upper surfaces. The second roller is mounted for rotation about a second axis parallel to the first axis, with first and second lower surfaces of rotation centered thereabout, the first surface mean diameter being less than that of the second surface, and the second roller having a lower trailing edge between the first and second lower surfaces. The first and second rollers are mounted for movement together and apart in a plane of the first and second axes for engagement and cold rolling of multiple outward steps in the piping element connection placed therebetween which are essentially parallel to the centerline of the piping element connection that is positioned therebetween.

대표청구항 ▼

An apparatus for cold roll forming multiple, generally coaxial steps in a circumferential wall of a piping element having a base circumference and a base wall thickness, said apparatus comprising an outside roller die mounted for rotation about a first axis, and an inside roller die mounted for rota

An apparatus for cold roll forming multiple, generally coaxial steps in a circumferential wall of a piping element having a base circumference and a base wall thickness, said apparatus comprising an outside roller die mounted for rotation about a first axis, and an inside roller die mounted for rotation about a second axis, parallel to said first axis, at least one of said outside roller die and said inside roller die mounted for pivoting movement about a pivot point on its respective axis, said outside roller die defining a first outside roller surface of rotation extending axially and centered about said first axis, a second outside roller surface of rotation extending axially and centered about said first axis, and a third outside roller surface of rotation extending axially and centered about said first axis, said first outside roller surface having a mean diameter, said second outside roller surface having a mean diameter, and said third outside roller surface having a mean diameter, the mean diameter of said third outside roller surface being less than the mean diameter of said second outside roller surface and greater than the mean diameter of said first outside roller surface, said inside roller die defining a first inside roller surface of rotation corresponding and opposed to said first outside roller surface, and extending axially and centered about said second axis, a second inside roller surface of rotation corresponding and opposed to said second outside roller surface and extending axially and centered about said second axis, and a third inside roller surface of rotation corresponding and opposed to said third outside roller surface and extending axially and centered about said second axis, said first inside roller surface having a mean diameter, said second inside roller surface having a mean diameter, and said third inside roller surface having a mean diameter, the mean diameter of said third inside roller surface being greater than the mean diameter of said second inside roller surface and less than the mean diameter of said first inside roller surface, said first, second and third outside roller surfaces positioned for engagement with an outside surface of the wall of the piping element, and said first, second and third inside roller surfaces positioned for engagement with an inside surface of the wall of the piping element, said first, second and third outside roller surfaces and together with said first, second and third inside roller surfaces defining a nip, said first axis, said second axis and said nip disposed in a common plane, and means for driving at least said outside roller die or said inside roller die to rotate about its respective axis, and means for urging together said outside roller die and said inside roller die, each being mounted for relative movement together and apart, in said plane of said first axis, said second axis and said nip, in a manner to engage the wall of a piping element disposed in said nip therebetween and applying sufficient compressive force for forming by cold rolling of multiple steps by reducing the thickness of the wall of the piping element connection disposed therebetween in said nip, said first outside roller surface being disposed in substantial axial registration with said first inside roller surface, said second outside roller surface being disposed in substantial axial registration with said second inside roller surface, and said third outside roller surface being disposed in substantial axial registration with said third inside roller surface, and said second outside roller surface having an axial length and said second inside roller having an axial length, the axial length of said second outside roller surface being less than the axial length of said second inside roller surface to provide a predetermined spacing dependent upon the base wall thickness of the piping element in which multiple steps are to be formed, whereby, during rotation of said outside roller die and said inside roller die, the wall thickness of the piping element is reduced about a first circumferential region of limited axial extent, a second region of limited axial extent, and a third region of limited axial extent, to increase the circumference of the piping element in the first, second and third circumferential regions by conservation of wall material, the degree of reduction of wall thickness, and the resulting circumference, in the third region being greater than the degree of reduction of wall thickness, and resulting circumference in the second region, and less than the degree of reduction of wall thickness, and resulting circumference in the first region, thereby to form by cold rolling multiple steps in a piping element connection placed in said nip between said outside and inside roller dies, the resulting circumference in the first, second and third regions being greater than the base circumference and the resulting wall thickness in the first, second and third regions being less than the base wall thickness, said bearing allowing equalization of the forces on said first, second and third regions as said outside roller die and said inside roller die are brought together.