Mechanical tube expander
AssigneeMannesmann Aktiengesellschaft
InventorsHermann Josef Frentzen, Richard Gerretz, Ewald Henn
Life of this patent
Estimating the term…
Abstract
A mechanical pipe expander for a step-by-step expanding of steel pipes formed with a spiral welded seam. The expander includes an expander head that performs the expanding made up of circumferentially arranged segments over which the pipe assumes a circumjacent position and after which the segments move radially outward to forcibly engage the inside of the pipe. In order to avoid the segments contacting the inside welded seams of the pipe, the segments are formed with one or more complementary spiral slots and if the pipe has cross welded seams with one or more corresponding cross spiral slots.
Claims18
A mechanical expander for an elongated metallic pipe formed with an inside welded spiral seam and with an inside welded cross seam, comprising:
- an expandable head constructed to allow a pipe to assume a circumjacent relationship therewith,
- said head including an outer working surface,
- means for displacing said working surface relative to the circumjacent pipe to impose an expanding force on the inside of the pipe,
- a first spiral slot in said working surface formed and arranged to coincide with the welded spiral seam of the pipe, and
- a second spiral slot in said working surface formed and arranged to coincide with the welded cross seam of the pipe.
A mechanical expander for an elongated metallic pipe formed with an inside welded spiral seam and with an inside welded cross seam, comprising:
- an expandable head constructed to allow a pipe to assume a circumjacent relationship therewith,
- said head including an outer working surface,
- means for displacing said working surface relative to the circumjacent pipe to impose an expanding force on the inside of the pipe,
- one or more first spiral slots in said working surface formed and arranged to coincide with the welded spiral seam of the pipe,
- one or more second spiral slots in said wporking surface formed and arranged to coincide with the welded cross seam of the pipe,
- means for positioning the pipe and said expander, one relative to the other and for aligning the pipe so that the pipe seams, when circumjacently positioned on the head will fall directly over the corresponding slots of said working surface.
Dependencies are inferred from the claim text.