Method of assembling a carriage assembly

1 . A method of assembling a first member and a second member, comprising the steps of:

aligning said first member and said second member;

pressing a crimping tool into a crimping hole provided in either of said first member or said second member, and applying ultrasonic vibration to said crimping tool;

detecting stress that acts on said crimping tool when said crimping tool is pressed into said crimping hole; and

controlling an amplitude of said ultrasonic vibration applied to said crimping tool in accordance with a magnitude of detected stress.

2 . A method of assembling a carriage assembly that aligns attachment holes provided in front ends of carriage arms and crimping portions provided on suspensions to set the suspensions on the carriage arms and then presses a metal ball through crimping holes provided in the crimping portions while applying ultrasonic vibration to a crimping tool to crimp the suspensions to the carriage arms,

wherein the suspensions are crimped to the carriage arms by detecting stress that acts on the crimping tool when the metal ball is pressed in by the crimping tool and controlling an amplitude of the ultrasonic vibration applied to the crimping tool so as to increase and decrease in accordance with the magnitude of the stress.

3 . A method of assembling a carriage assembly that aligns attachment holes provided in front ends of carriage arms and crimping portions provided on suspensions to set the suspensions on the carriage arms that are disposed on a plurality of levels and then presses a metal ball successively through crimping holes provided in the crimping portions while applying ultrasonic vibration to a crimping tool to crimp the suspensions to the carriage arms,

wherein the suspensions are crimped to the carriage arms by carrying out control to not apply ultrasonic vibration to the crimping tool when the metal ball has come out of a crimping hole on an upper level and is at an intermediate position for insertion into a crimping hole on a next level.

4 . A method of assembling a carriage assembly that aligns attachment holes provided in front ends of carriage arms and crimping portions provided on suspensions to set the suspensions on the carriage arms and then carries out a plurality of iterations of a crimping operation that presses a metal ball through crimping holes provided in the crimping portions while applying ultrasonic vibration to a crimping tool to crimp the suspensions to the carriage arms,

wherein the suspensions are crimped to the carriage arms by setting a frequency of the ultrasonic vibration applied to the crimping tool during the crimping operation that presses the metal ball into the crimping holes so that the frequency is lower in later iterations of the crimping operation than in earlier iterations.

5 . A method of assembling a carriage assembly according to claim 3 , wherein stress that acts on the crimping tool when the suspensions are crimped to the carriage arms is detected and an amplitude of the ultrasonic vibration applied to the crimping tool is controlled so as to increase and decrease in accordance with the magnitude of the stress.

6 . A method of assembling a carriage assembly according to claim 4 , wherein stress that acts on the crimping tool when the suspensions are crimped to the carriage arms is detected and an amplitude of the ultrasonic vibration applied to the crimping tool is controlled so as to increase and decrease in accordance with the magnitude of the stress.

7 . A method of assembling a carriage assembly that aligns attachment holes provided in front ends of carriage arms and crimping portions provided on suspensions to set the suspensions on the carriage arms and then presses an operation portion, which is formed at a front end of a crimping tool so that a maximum external diameter thereof is larger than an inner diameter of crimping holes provided in the crimping portions, through the crimping holes while applying ultrasonic vibration to the crimping tool to crimp the suspensions to the carriage arms,

wherein the suspensions are crimped to the carriage arms by detecting stress that acts on the crimping tool when the operation portion passes through the crimping holes and controlling an amplitude of the ultrasonic vibration applied to the crimping tool so as to increase and decrease in accordance with a magnitude of the stress.

8 . A method of assembling a carriage assembly that aligns attachment holes provided in front ends of carriage arms and crimping portions provided on suspensions to set the suspensions on the carriage arms and then carries out a plurality of iterations of a crimping operation that presses an operation portion, which is formed at a front end of a crimping tool so that a maximum external diameter thereof is larger than an inner diameter of crimping holes of the crimping portions, through the crimping holes while applying ultrasonic vibration to the crimping tool to crimp the suspensions to the carriage arms,

wherein the suspensions are crimped to the carriage arms by setting a frequency of the ultrasonic vibration applied to the crimping tool during the crimping operation that presses the operation portion into the crimping holes so that the frequency is lower in later iterations of the crimping operation than in earlier iterations.