Apparatus for adjusting a slide stroke of a press machine

An apparatus for adjusting the stroke of a slide of a press machine, comprising:

• at least one crank shaft attached to a housing and having a circular eccentric portion;
• an eccentric sleeve fitted over said circular eccentric portion in eccentric relationship thereto;
• a connecting rod having an upper end fitted over said eccentric sleeve and having a lower end connected to said slide, wherein rotation of said eccentric sleeve relative to said circular eccentric portion changes an angular phase between said circular eccentric portion and said eccentric sleeve to adjust a vertical stroke of said slide in response to rotation of said crank shaft;
• a main motor;
• a speed decreasing motor;
• at least one drive shaft;
• said main motor and said speed decreasing motor driving said at least one drive shaft;
• first teeth provided on said eccentric sleeve in concentric relationship to said circular eccentric portion;
• at least one main gear disposed coaxially with and on said at least one crank shaft and driven by said at least one drive shaft;
• second teeth provided on said main gear coaxially with said crank shaft and meshing with said first teeth;
• means for moving said crank shaft axially;
• a coupling provided between said crank shaft and said main gear for disconnecting and connecting said at least one crank shaft and said main gear in response to an axial movement of said crank shaft;
• and
• means for preventing said crank shaft which has moved axially from rotating.