Method for forming reduced diameter ends on elongated workpieces

Claim 2

In the method for forming reduced diameter ends on an elongated cylindrical workpiece, the steps of: positioning said workpiece between and coaxial with a pair of dies through which ends of the workpiece can pass, the dies having facing tapered die openings for receiving the respective ends of the workpiece, moving at least one of said dies toward the other die until the opposite ends of the workpiece engage the tapered openings of the respective dies, thereafter forcing at least one of said dies toward the other die until both ends of the workpiece have passed through the respective dies with the ends of the workpiece comprising cylindrical portions reduced in diameter with respect to the original diameter of the workpiece and having radiallyoutwardly flared ends, and retracting said one die from the workpiece while exerting a force on said radially-outwardly flared end tending to move it through said one die in a direction opposite to the retracting movement of the die to extricate said end from the one die.

Claim 3

The method of claim 1 including the step of moving at least one of said dies away from the other after the ends of the workpiece have been reduced in diameter to extract said ends from the dies.

Claim 4

The method of claim 1 wherein said workpiece is positioned between the dies in an unclamped condition such that it can move toward one die under the force of the other die.

Claim 5

The method of claim 1 wherein one of said dies is fixed while the other is reciprocable toward and way from the fixed die.

Claim 6

In the method for forming reduced diameter ends on an elongated workpiece, the steps of: positioning said workpiece between and coaxial with a pair of dies through which ends of the workpiece can pass, the dies having facing tapered die openings for receiving the respective ends of the workpiece, one of said dies being fixed and the other being reciprocable toward and away from said fixed die; moving said reciprocable die toward tHe fixed die while pushing the workpiece toward the fixed die until the opposite ends of the workpiece are received within the respective die openings; continuing movement of the reciprocable die toward the fixed die while exerting sufficient pressure on the reciprocable die to force it over one end of the workpiece with the end of the workpiece projecting through the die while forcing the other end of the workpiece through the fixed die to form cylindrical portions on the ends of the workpiece which are reduced in diameter with respect to the original diameter of the workpiece, the ends of the workpiece being flared radially outwardly in passing through the dies, and retracting the reciprocable die while exerting a force on the flared end of the workpiece in the reciprocable die in a direction opposite to the direction of retraction to extricate the end of the workpiece from said reciprocable die.

Claim 7

In the method for forming reduced diameter ends on an elongated workpiece, the steps of: positioning said workpiece between and coaxial with a pair of dies through which ends of the workpiece can pass, the dies having facing tapered die openings for receiving the respective ends of the workpiece, one of said dies being fixed and the other being reciprocable toward and away from said fixed die; moving said reciprocable die toward tHe fixed die while pushing the workpiece toward the fixed die until the opposite ends of the workpiece are received within the respective die openings; continuing movement of the reciprocable die toward the fixed die while exerting sufficient pressure on the reciprocable die to force it over one end of the workpiece with the end of the workpiece projecting through the die while forcing the other end of the workpiece through the fixed die to form cylindrical portions on the ends of the workpiece which are reduced in diameter with respect to the original diameter of the workpiece, the ends of the workpiece being flared radially outwardly in passing through the dies, and retracting the reciprocable die while exerting a force on the flared end of the workpiece in the reciprocable die in a direction opposite to the direction of retraction to extricate the end of the workpiece from said reciprocable die.

Claim 8

The method of claim 5 including the step of forcing the end of the workpiece entering the fixed die against a tapered surface to compensate for said flared end, whereby the end of the workpiece in the fixed die can be easily retracted therefrom upon movement of the movable die away from the fixed die which engages the flared end of the workpiece in said movable die.

Claim 9

The method of claim 6 including the step of forcing said flared end out of said movable die and after the opposite end of the workpiece has been removed from the fixed die upon retraction of the movable die.

Claim 10

The method of claim 7 including the step of forcing a plug into engagement with a reduced diameter end of the workpiece as the reciprocable die is forced thereover, and maintaining pressure on said plug tending to move it against the workpiece as said reciprocable die is retracted from the reduced diameter end whereby the plug will force the end of the tube through the die opening.

Claim 11

In the method of forming a reduced diameter end of an elongated workpiece, the steps of forcing a reciprocal die over said end of the workpiece such that the wrokpiece projects through the die and has a radially-outwardly flared end, the die having a diameter less than that of the original diameter of the workpiece, forcing a plug to move with the die under fluid pressure and into engagement with the reduced diameter end of the workpiece as said reciprocal die is forced thereover, providing a portion on said plug which will engage the die and limit movement of the plug through the die, exerting a force on said die to retract it from the end of the workpiece, and maintaining pressure on said plug tending to move it against the workpiece as said reciprocal die is retracted from the reduced diameter end whereby the plug will force the end of the tube through the die opening, the pressure maintained on said plug during the retraction of the die being sufficient to strip the die from the flared end of the workpiece but insufficient to prevent retraction of the die and plug when said portion of the plug engages the die during retraction.

Claim 12

In the method of forming a reduced diameter end of an elongated workpiece, the steps of forcing a reciprocal die over said end of the workpiece such that the wrokpiece projects through the die and has a radially-outwardly flared end, the die having a diameter less than that of the original diameter of the workpiece, forcing a plug to move with the die under fluid pressure and into engagement with the reduced diameter end of the workpiece as said reciprocal die is forced thereover, providing a portion on said plug which will engage the die and limit movement of the plug through the die, exerting a force on said die to retract it from the end of the workpiece, and maintaining pressure on said plug tending to move it against the workpiece as said reciprocal die is retracted from the reduced diameter end whereby the plug will force the end of the tube through the die opening, the pressure maintained on said plug during the retraction of the die being sufficient to strip the die from the flared end of the workpiece but insufficient to prevent retraction of the die and plug when said portion of the plug engages the die during retraction.

Claim 13

The method of claim 9 including the step of initially aligning said workpiece with the die and causing said plug to move with the die as it approaches the end of the tube, the plug continually moving with the die until it engages the end of the workpiece passing through the die.