Roller swaging machine

A method for installing a metallic fitting on a metallic tube by roller-swaging where a tapered mandrel is rotated and fed into the tube to expand the tube into engagement with the fitting, wherein the mandrel requires a final torque as the tube reaches complete expansion, comprising the steps of:

• (a) during a first period of time, during which time the torque on the mandrel reaches a ramp threshold torque of less than 50 percent of the final torque, rotating the mandrel at a first high speed for rapidly expanding the tube into engagement with the fitting;
• (b) during a second period of time in which the torque increases from the ramp threshold torque to an intermediate torque of at least 60 percent of the final torque, reducing the speed of the mandrel to a lower second speed of between about 10 and 30 percent of the first speed, the second speed not being exceeded once the mandrel requires at least 90 percent of the final torque;
• and
• (c) rotating the mandrel at the second speed until swaging is complete.

A method for installing a metallic fitting on a metallic tube by roller-swaging a tapered mandrel is rotated and fed into the tube to expand the tube into engagement with the fitting, the rotation continuing until the torque on the mandrel reaches a final preselected value, comprising the steps of:

• (a) during a first period of time, during which time the torque on the mandrel reaches a ramp threshold value of less than about 50 percent of the final preselected value, rotating the mandrel at a first high speed for rapidly expanding the tube into engagement with the fitting;
• (b) during a second period of time in which the torque increases form the ramp threshold torque to an intermediate torque of at least 60 percent of the final preselected value, reducing the speed of the mandrel to a lower second speed, the lower second speed being between about 10 and 30 percent of the first speed, the second not being exceeded once the torque on the mandrel reaches 70 percent of the first preselected value;
• and
• (c) rotating the mandrel at the second speed until the torque reaches the final preselected value.

A roller swaging machine for installing a metallic sleeve on a metallic tube by expanding the tube into engagement with the sleeve, the machine comprising:

• (a) an expander assembly having a tapered mandrel for engaging a plurality of tapered rollers for expanding the tube as the mandrel is rotated and advanced on its axis;
• (b) a drive for rotating the mandrel in a swaging cycle, the drive being capable of rotating the mandrel at a high speed and at low speeds;
• and
• (c) control means for the drive for
• (i) rotating the mandrel at the high speed during initial expansion of the tube;
• (ii) during further expansion of the tube, when rotation of the mandrel requires more than a ramp threshold level of less than about 50 percent of a preset maximum torque value, ramping the mandrel speed downwardly to a low speed of between about 10 to 30 percent of the high speed, the low speed being reached when the torque is at least about 70 percent of the final maximum torque value;
• and
• (iii) continuing at the low speed until swaging is complete.

A method for installing a metallic fitting on a metallic tube by roller-swaging where a tapered mandrel is rotated and fed into the tube to expand the tube into engagement with the fitting the rotation expansion continuing until the diameter of the mandrel reaches a final preselected value, comprising the steps of:

• (a) during a first period of time, during which time the torque on the mandrel reaches about 30 percent of the final torque, rotating the mandrel at a first high speed for rapidly expanding the tube into engagement with the fitting;
• (b) during a second period of time, ramp reducing the speed of the mandrel to a lower speed, the lower second speed being about 20 percent of the first speed, the second speed not being reached until the torque on the mandrel reaches at least about 70 percent of the final value, and not being exceeded once the torque on the mandrel reaches at least 90 percent of the final value;
• (c) rotating the mandrel at the second speed until the diameter of the mandrel reaches the preselected value;
• and
• (d) continuing the rotation at the second speed for a preselected time to effect tube burnishing, the torque being reduced from the final value.

A roller swaging machine for installing a metallic sleeve on metallic tube by expanding the tube into engagement with the sleeve, the machine comprising:

• (a) an expander assembly having a tapered mandrel for engaging a plurality of tapered rollers for expanding the tube as the mandrel is rotated and advanced on its axis;
• (b) a drive for rotating the mandrel in a swaging cycle, the drive being capable of rotating the mandrel at a high speed and at low speeds;
• and
• (c) control means for the drive for
• (i) rotating the mandrel at the high speed during initial expansion of the tube;
• (ii) during further expansion of the tube, when rotation of the mandrel requires more than about 30 percent of the final maximum torque, ramping the mandrel speed downwardly to a low speed between about 10 to 30 percent of the high speed;
• and
• (iii) selectively either reaching the limit of expansion under diameter control of the expander whereby maximum expansion is achieved after commencement of the low speed, or controlling the swage under torque control, whereby maximum expansion is achieved at about the end of the low speed cycle, the expansion increasing to a final value during the low speed operation.

A method for installing a metallic fitting on a metallic tube by roller-swaging where a tapered mandrel is rotated and fit into the tube to expand the tube into engaging with the fitting, comprising the steps of:

• (a) during a first period of time, during which the torque required for rotating the mandrel reaches about 30 percent of the final torque, rotating the mandrel at a high first speed for rapidly expanding the tube into engagement with the fitting;
• (b) during a second period of time ramp reducing the speed of the mandrel to a lower second speed, the second speed being between about 10 to 30 percent of the first speed, the second speed being reached after the torque required for rotating the mandrel reaches at least about 70 percent of the final torque;
• and
• (c) selectively either increasing the torque at the commencement at the second speed and concluding swaging when a maximum torque is reached whereby controlling the swage by torque control, or reaching about maximum torque at the beginning of the second speed period whereafter expansion is limited and the torque no longer increases such that the tube expansion is effected by diameter control of mandrel expansion.