Rotary woodworking machine

A rotary woodworking machine comprising:

• a machine frame having first and second walls opposite to each other in a longitudinal direction;
• a motor with an output shaft extending along and rotatable about a first axis parallel to the longitudinal direction to deliver a drive force, said output shaft having a coupling end which is disposed between said first and second walls;
• a transmitting shaft extending along and rotatable about a second axis parallel to the first axis, and having first and second ends which extend outwardly of said first and second walls, respectively, and a middle portion which is disposed between said first and second ends;
• first and second rotary woodworking members coupled to and rotatable with said first and second ends of said transmitting shaft;
• and
• a speed ratio varying device including
• a first pulley having a first fixed disc which is mounted securely on said middle portion, and a first movable disc which is splined to said middle portion to be movable relative to said first fixed disc along the second axis, said first fixed and movable discs respectively having first belt-engaging surfaces which cooperatively define therebetween a first belt receiving space,
• a control unit mounted on said machine frame, and having an operable member which is turnable to move said first movable disc along the second axis so as to be disposed close to or remote from said first fixed disc,
• a second pulley having a second fixed disc which is mounted securely on said coupling end, and a second movable disc which is splined to said coupling end to be movable relative to said second fixed disc along the first axis, said second fixed and movable discs respectively having second belt-engaging surfaces which cooperatively define therebetween a second belt receiving space,
• a biasing member disposed to bias said second movable disc toward said second fixed disc, and
• a belt trained on said first and second pulleys, and frictionally slidable on said first and second belt-engaging surfaces, said belt having a first lengthwise end which cooperates with said middle portion to define a first radial distance therebetween, and a second lengthwise end which is opposite to said first lengthwise end in a first direction transverse to the longitudinal direction and which cooperates with said coupling end to define a second radial distance therebetween such that, turning of said operable member results in movement of said first movable disc along the second axis between
• a first position, where said first movable disc is close to said first fixed disc so that said first lengthwise end is remote from said middle portion so as to result in a greater length of the first radial distance, and where said second movable disc is kept apart from said second fixed disc by a tension force which is generated as a result of displacement of said second lengthwise end toward said coupling end of said output shaft and which acts against biasing action of said biasing member, and
• a second position, where said first movable disc is remote from said first fixed disc so that said first lengthwise end is proximate to said middle portion so as to result in a smaller length of the first radial distance, and where said second movable disc is held close to said second fixed disc by the biasing action of said biasing member.