Method and apparatus for producing a substantially cylindrical hollow article

Claim 1

An apparatus for producing a cylindrical hollow member comprising at least one pair of rollers for rotatably supporting a hollow parent member thereon for rotation about a horizontal axis thereof; a plurality of clevises, each said clevis rotatably mounting a respective one of said rollers thereon; a block slidably receiving each clevis thereon and defining a pressure chamber with each clevis; a control means connected to at least one roller pair to alternatively maintain one roller of said roller pair in bearing engagement with the hollow member while relieving the other roller of said roller pair from bearing engagement with the hollow member; said control means including a tank for a liquid pressure medium, a pair of lines extending from said tank, each said line being connected to a respective pressure chamber in said block, a pair of valves, each said valve being disposed in a respective line to control a flow of pressure medium therethrough, a pump for pumping liquid pressure medium into said tank while maintaining an air cushion above the pressure medium and a third control valve connected to said tank to exhaust air from the air cushion; means for applying build-up welding to the hollow member during rotation of the hollow member to form a built-up member; and drive means connected to at least one of said roller pairs for driving said one roller pair to rotate the hollow parent member.

Claim 2

An apparatus for producing a cylindrical hollow member comprising at least one pair of rollers for rotatably supporting a hollow parent member thereon for rotation about a horizontal axis thereof; a plurality of clevises, each said clevis rotatably mounting a respective one of said rollers thereon; a block slidably receiving each clevis thereon and defining a pressure chamber with each clevis; a control means connected to at least one roller pair to alternatively maintain one roller of said roller pair in bearing engagement with the hollow member while relieving the other roller of said roller pair from bearing engagement with the hollow member; said control means including a tank for a liquid pressure medium, a pair of lines extending from said tank, each said line being connected to a respective pressure chamber in said block, a pair of valves, each said valve being disposed in a respective line to control a flow of pressure medium therethrough, a pump for pumping liquid pressure medium into said tank while maintaining an air cushion above the pressure medium and a third control valve connected to said tank to exhaust air from the air cushion; means for applying build-up welding to the hollow member during rotation of the hollow member to form a built-up member; and drive means connected to at least one of said roller pairs for driving said one roller pair to rotate the hollow parent member.

Claim 3

An apparatus for producing a cylindrical hollow member comprising at least one pair of rollers for rotatably supporting a hollow parent member thereon for rotation about a horizontal axis; means for applying build-up welding to said hollow member during rotation of the hollow member to form a built-up member; and a control means connected to said pair of rollers to selectively maintain one roller in a bearing state relative to the hollow member while maintaining the other roller in a resilient state relative to the hollow member, said control means including a tank for receiving a liquid pressure medium while maintaining an air cushion above the pressure medium, a pump connected to said tank for pumping liquid pressure medium into said tank, a pair of pressure chambers, each chamber being disposed below a respective roller, a pair of lines, each said line being connected to and between said tank and a respective pressure chamber to convey pressure medium therebetween, a pair of control valves, each said valve being disposed in a respective line to selectively open said line to place a respective roller in a resilient state and close said line to place said respective roller in a bearing state, and a third control valve connected to said tank to exhaust air from the air cushion whereby opening of one of said pair of valves permits the respective roller to descend under an increasing diameter of the built-up hollow member.

Claim 4

An apparatus for producing a cylindrical hollow member comprising at least one pair of rollers for rotatably supporting a hollow parent member thereon for rotation about a horizontal axis; means for applying build-up welding to said hollow member during rotation of the hollow member to form a built-up member; and a control means connected to said pair of rollers to selectively maintain one roller in a bearing state relative to the hollow member while maintaining the other roller in a resilient state relative to the hollow member, said control means including a tank for receiving a liquid pressure medium while maintaining an air cushion above the pressure medium, a pump connected to said tank for pumping liquid pressure medium into said tank, a pair of pressure chambers, each chamber being disposed below a respective roller, a pair of lines, each said line being connected to and between said tank and a respective pressure chamber to convey pressure medium therebetween, a pair of control valves, each said valve being disposed in a respective line to selectively open said line to place a respective roller in a resilient state and close said line to place said respective roller in a bearing state, and a third control valve connected to said tank to exhaust air from the air cushion whereby opening of one of said pair of valves permits the respective roller to descend under an increasing diameter of the built-up hollow member.