Driving device used in sewing apparatus

Abstract

A sewing apparatus includes a driving source, a second driven shaft, and an eccentric member of an eccentric mechanism. The second driven shaft is connected to a drive shaft of the driving source and rotates. The eccentric member is connected to the second driven shaft. The eccentric member is capable of converting the rotational motion of the second driven shaft into the up and down motion of sewing machine needles. A cushion member is disposed between the eccentric member and the second driven shaft.

What is claimed is: 
     
         1 . A driving device that is used in a sewing apparatus for sewing a workpiece, and that drives a needle, the driving device comprising:
 a driving source configured to be driven to rotate when energized;   a shaft connected to the driving source and configured to rotate; and   an eccentric member fixed to the shaft and configured to convert a rotational motion of the shaft into an up and down motion of the needle, wherein   a cushion member configured to absorb a load applied to the eccentric member in a direction substantially orthogonal to an axial direction of the shaft is disposed between the eccentric member and the shaft.   
     
     
         2 . The driving device according to  claim 1 , wherein
 the eccentric member includes:   a first cylindrical portion formed coaxially with an axial center of the shaft; and   a second cylindrical portion disposed on one side of the first cylindrical portion in the axial direction of the shaft, and radially eccentric from the axial center of the shaft, and   the cushion member is disposed in the second cylindrical portion.   
     
     
         3 . The driving device according to  claim 2 , wherein
 the eccentric member and the shaft are fixed to each other by a fixing member provided in the first cylindrical portion.   
     
     
         4 . The driving device according to  claim 1 , wherein
 the cushion member has an annular shape.   
     
     
         5 . The driving device according to  claim 1 , wherein
 the cushion member is formed of an incompressible material.