Process for cold forming a metal tube with an inwardly thickened end

Claim 1

A method for forming an elongated tubular metal axle-like part having one end formed with reduced outer diameter portions and the opposite end formed with an inwardly thickened portion and a central barrel portion of uniform diameter and thickness, comprising: separately forming the part in two separate pieces, namely, one piece having the formed reduced outer diameter portions with that piece terminating at the barrel portion, and a second piece consisting of the barrel portion and the inwardly thickened portion, comprising extruding said second piece by: positioning a relatively short tubular blank within a die mounted upon the base of a press having an aligned ram, with the die having an open inlet end with a blank receiving portion and an outlet end having an inwardly extending annular extrusion shoulder whose inner cross-sectional diameter is smaller than that of the blank receiving portion for extruding the blank therethrough; ram pushing the blank partway through the die shoulder for thereby extruding the barrel portion on the blank, leaving the remaining portion of the blank still within the die blank receiving portion; next, inserting a second, identical blank into the die blank receiving portion in end to end contact with the first mentioned blank; then ram pushing the second blank through the die shoulder to form a barrel portion thereon, thereby simultaneously forcing the first blank completely through the die shoulder to cause the portion previously remaining within the die blank receiving portion to flow inwardly to form the inwardly thickened portion of the piece, and then repeating the cycle of inserting a new blank, etc.; and thereafter welding said extruded second piece to a preformed first piece end to end, to form the completed axle-like part.

Claim 2

A method for forming an elongated tubular metal axle-like part having one end formed with reduced outer diameter portions and the opposite end formed with an inwardly thickened portion and a central barrel portion of uniform diameter and thickness, comprising: separately forming the part in two separate pieces, namely, one piece having the formed reduced outer diameter portions with that piece terminating at the barrel portion, and a second piece consisting of the barrel portion and the inwardly thickened portion, comprising extruding said second piece by: positioning a relatively short tubular blank within a die mounted upon the base of a press having an aligned ram, with the die having an open inlet end with a blank receiving portion and an outlet end having an inwardly extending annular extrusion shoulder whose inner cross-sectional diameter is smaller than that of the blank receiving portion for extruding the blank therethrough; ram pushing the blank partway through the die shoulder for thereby extruding the barrel portion on the blank, leaving the remaining portion of the blank still within the die blank receiving portion; next, inserting a second, identical blank into the die blank receiving portion in end to end contact with the first mentioned blank; then ram pushing the second blank through the die shoulder to form a barrel portion thereon, thereby simultaneously forcing the first blank completely through the die shoulder to cause the portion previously remaining within the die blank receiving portion to flow inwardly to form the inwardly thickened portion of the piece, and then repeating the cycle of inserting a new blank, etc.; and thereafter welding said extruded second piece to a preformed first piece end to end, to form the completed axle-like part.

Claim 3

A method for forming an elongated tubular metal axle-like part having one end formed with reduced outer diameter portions and the opposite end formed with an inwardly thickened portion and a central barrel portion of uniform diameter and thickness, comprising: separately forming the part in two separate pieces, namely, one piece having the formed reduced outer diameter portions with that piece terminating at the barrel portion, and a second piece consisting of the barrel portion and the inwardly thickened portion, comprising extruding said second piece by: positioning a relatively short tubular blank within a die mounted upon the base of a press having an aligned ram, with the die having an open inlet end with a blank receiving portion and an outlet end having an inwardly extending annular extrusion shoulder whose inner cross-sectional diameter is smaller than that of the blank receiving portion for extruding the blank therethrough; ram pushing the blank partway through the die shoulder for thereby extruding the barrel portion on the blank, leaving the remaining portion of the blank still within the die blank receiving portion; next, inserting a second, identical blank into the die blank receiving portion in end to end contact with the first mentioned blank; then ram pushing the second blank through the die shoulder to form a barrel portion thereon, thereby simultaneously forcing the first blank completely through the die shoulder to cause the portion previously remaining within the die blank receiving portion to flow inwardly to form the inwardly thickened portion of the piece, and then repeating the cycle of inserting a new blank, etc.; and thereafter welding said extruded second piece to a preformed first piece end to end, to form the completed axle-like part.

Claim 4

A method for forming an elongated tubular metal axle-like part having one end formed with reduced outer diameter portions and the opposite end formed with an inwardly thickened portion and a central barrel portion of uniform diameter and thickness, comprising: separately forming the part in two separate pieces, namely, one piece having the formed reduced outer diameter portions with that piece terminating at the barrel portion, and a second piece consisting of the barrel portion and the inwardly thickened portion, comprising extruding said second piece by: positioning a relatively short tubular blank within a die mounted upon the base of a press having an aligned ram, with the die having an open inlet end with a blank receiving portion and an outlet end having an inwardly extending annular extrusion shoulder whose inner cross-sectional diameter is smaller than that of the blank receiving portion for extruding the blank therethrough; ram pushing the blank partway through the die shoulder for thereby extruding the barrel portion on the blank, leaving the remaining portion of the blank still within the die blank receiving portion; next, inserting a second, identical blank into the die blank receiving portion in end to end contact with the first mentioned blank; then ram pushing the second blank through the die shoulder to form a barrel portion thereon, thereby simultaneously forcing the first blank completely through the die shoulder to cause the portion previously remaining within the die blank receiving portion to flow inwardly to form the inwardly thickened portion of the piece, and then repeating the cycle of inserting a new blank, etc.; and thereafter welding said extruded second piece to a preformed first piece end to end, to form the completed axle-like part.