Cold rolling positioning roller assembly

A positioning roller assembly for use when cold rolling a tube, the tube defining a longitudinal axis, comprising:

• first and second positioning rollers disposed for initial contact with a tube surface to apply a load upon the tube surface generally directed along a direction of load applied by an outer groove roll,
• a face plate for mounting of said first and second positioning rollers at set relative positions offset axially from the outer groove roll and an inner groove roll during cold rolling, said face plate being mounted for movement with an outside groove roll,
• a spring for positioning of said first and second positioning rollers during cold rolling, said spring providing for movement of said face plate relative to said outside groove roll during cold rolling, and
• a rod mounted to a carrier assembly to which the outside groove roll is fixedly mounted, said spring being mounted to said rod and constrained between said face plate and the carrier assembly whereby motion of said positioning rollers acts upon said spring.

A cold rolling machine for cold rolling a tube, the tube defining a longitudinal axis, comprising:

• an outside groove roll,
• an inside groove roll, and
• a positioning roller assembly comprising:
• first and second positioning rollers disposed for initial contact with a tube surface to apply a load upon the tube surface generally directed along a direction of load applied by the outside groove roll,
• a face plate for mounting of said positioning rollers at set relative positions offset axially from said groove rollers during cold rolling, said face plate being mounted for movement with said outside groove roll, and
• a mechanism for positioning of said positioning rollers during cold rolling, said mechanism providing for movement of said face plate relative to said outside groove roll during cold rolling.

A method of cold rolling a tube, the tube defining a longitudinal axis, comprising the steps of:

• a. providing a cold rolling apparatus comprising
• an outside groove roll,
• an inside groove roll, and
• a positioning roller assembly comprising:
• first and second positioning rollers disposed for initial rollers contact with a tube surface to apply a load upon the tube surface generally directed along a direction of load applied by the outside groove roll,
• a face plate for mounting of said first and second positioning rollers at set relative positions offset axially from said outside and inside groove rolls during cold rolling, said face plate being mounted for movement with said outside groove roll, and
• a mechanism for positioning of said positioning rollers during cold rolling, said mechanism providing for movement of said face plate relative to said outside groove roll during cold rolling,
• b. positioning an end of a tube to be cold rolled between said outside and inside groove rolls,
• c. moving said outside groove roll and said positioning rollers into contact with an outside surface of said tube such that said tube is held between said outside groove roll and said inside groove roll, and
• d. further moving said outside groove roll toward said inside groove roll to cold roll said tube while said mechanism maintains contact of said positioning rollers with said tube during cold rolling.