Rotary metal extrusion apparatus

A method of extruding metal by operating rotary metal extrusion apparatus comprising a drum rotatable about an axis and having a curved peripheral surface with a circumferential groove therein, a curved shoe located adjacent said peripheral surface of said drum, said shoe having a projecting portion projecting into said groove to form a passageway with the surfaces of said groove, said shoe also having shoulder portions adjacent said projecting portion, said shoulder portions mating with the peripheral surfaces of said drum adjacent said groove for relative movement with respect thereto, the sides of said projecting portion of said shoe and the sides of said groove having clearance spaces therebetween, an abutment member fixed with respect to said shoe and closing one end of said passageway, and a die located at said closed end of said passageway, said method comprising the steps of:

• introducing, into said circumferential groove in said drum, metal to be extruded;
• rotating said drum and thereby moving it with respect to said shoe so that frictional drag of the surfaces of said groove draws said metal through said passageway and toward said die;
• extruding metal through an orifice in said die to produce an extrusion;
• allowing a small quantity of the metal in said groove to flow through said clearance spaces as metal is extruded through said die orifice;
• and
• permitting a part of said metal flowed through said clearance spaces to be forced between said shoulder portions of said shoe and said peripheral surfaces of said drum mating therewith, so as to form therebetween a thin bearing layer of the metal;
• said shoulder portions including a different bearing material that is in contact with said thin bearing layer.

Rotary metal extrusion apparatus comprising:

• a drum rotatable about an axis and having a curved peripheral surface with a circumferential groove therein;
• a curved shoe located adjacent said peripheral surface of said drum;
• said shoe having a projecting portion projecting into said groove to form a passageway with the surfaces of said groove;
• said shoe also having shoulder portions adjacent said projecting portion;
• said shoulder portions mating with the peripheral surfaces of said drum adjacent said groove for relative movement with respect thereto;
• the sides of said projecting portion of said shoe and the sides of said groove having clearance spaces therebetween;
• an abutment member fixed with respect to said shoe and closing one end of said passageway;
• a die located at said closed end of said passageway;
• a bearing material disposed between the shoulder portions of the shoe and said peripheral surfaces of said drum adjacent said groove, said bearing material being different from the materials of said shoe and said drum and different from the metal to be extruded, and
• means for moving said drum relative to said shoe so that frictional drag of the surfaces of said groove draws metal in said groove toward said die for extrusion through an orifice in said die;
• said clearance spaces providing a passage for a small quantity of said metal to flow therethrough so that a portion of said metal passes between said mating surfaces of said drum and said shoulders of said shoe to form a bearing layer thereof in contact with said bearing material.

Rotary metal extrusion apparatus comprising:

• a drum rotatable about an axis and having a curved peripheral surface with a circumferential groove therein;
• a curved shoe located adjacent said peripheral surface of said drum;
• said shoe having a projecting portion projecting into said groove to form a passageway with the surfaces of said groove;
• said shoe also having shoulder portions adjacent said projecting portion;
• said shoulder portions mating with the peripheral surfaces of said drum adjacent said groove for relative movement with respect thereto;
• said shoulder portions comprising a bearing material that is different from said drum and said shoe;
• the sides of said projecting portion of said shoe and the sides of said groove having clearance spaces therebetween;
• an abutment member fixed with respect to said shoe and closing one end of said passageway;
• a die located at said closed end of said passageway;
• and
• means for moving said drum relative to said shoe so that frictional drag of the surfaces of said groove draws metal in said groove toward said die for extrusion through an orifice in said die;
• said clearance spaces providing a passage for a small quantity of said metal to flow therethrough so that a portion of said metal passes between said mating surfaces of said drum and said shoulders of said shoe to form a layer of bearing material on at least said drum surfaces.

Rotary metal extrusion apparatus comprising:

• a drum rotatable about an axis and having a curved peripheral surface with a circumferential groove therein;
• a curved shoe located adjacent said peripheral surface of said drum;
• said shoe having a projecting portion projecting into said groove to form a passageway with the surfaces of said groove;
• said shoe also having shoulder portions adjacent said projecting portion;
• said shoulder portions mating with the peripheral surfaces of said drum adjacent said groove for relative movement with respect thereto;
• the sides of said projecting portion of said shoe and the sides of said groove having clearance spaces therebetween;
• an abutment member fixed with respect to said shoe and closing one end of said passageway;
• a die located at said closed end of said passageway;
• and
• means for moving said drum relative to said shoe so that frictional drag of the surfaces of said groove draws metal in said groove toward said die for extrusion through an orifice in said die;
• said clearance spaces providing a passage for a small quantity of said metal to flow therethrough so that a portion of said metal passes between said mating surfaces of said drum and said shoulders of said shoe to form a layer of bearing material on at least said drum surfaces, and
• the depth of said circumferential groove being uniform about its entire circumference and the depth to which said projecting portion of said shoe projects into said groove decreasing with distance from said die.