Door moving mechanism for a cutting machine

A cutting machine including a machine body, an upright support adjacent to said machine body and a casing mounted on said upright support movable upward and downward along said upright support and having a surrounding side wall and an open top, said casing having a cutting device provided therein and operable when said casing is moved downward to a first position, said machine further having a cutter exchanging plate rotatably provided on said machine body above said upright support and adapted to exchange a cutter with said cutting device of said casing when said casing moves upward to a second position above said first position, a door covering mechanism provided on said machine body immediately above said upright support between said cutter exchanging plate and said upright support and being slidable in a horizontal direction between a third position covering said open top of said casing when said casing is at said first position, and a fourth position uncovering said open top of said casing when said casing is at said second position to permit the cutter exchanging operation, and a door moving mechanism for moving said door covering mechanism;

• the improvement comprising:
• said moving mechanism including a horizontal guide rail disposed on said machine body immediately above said upright support;
• a connecting rod provided slidably in said horizontal guide rail and having first end attached to said door covering mechanism and a second end;
• an elongated first rod having a first end pivoted on said machine body adjacent to said upright support and said guide rail and a second end opposite to said first end, said elongated first rod further having a first lobed part and a second lobed part formed thereon adjacent to said pivot point, said first and second lobed parts respectively having a first contact face and a second contact face and cooperatively defining a receiving space therebetween, said first and second contact faces respectively being above and below a horizontal line drawn across said pivot point;
• an elongated second rod has a first end pivoted to said second end of said elongated first rod and a second end pivoted to said second end of said connecting rod;
• said casing having a push member formed at an uppermost portion thereof and including a push rod, a free end of which extends into said receiving space to abut against one of said contact faces upon movement of said casing along said upright support;
• whereby movement of said casing upwardly along said upright support causes said free end of said push rod to abut against said first contact face of said first lobed thereby pivoting said elongated first rod in a first direction, said second elongated rod correspondingly moves said connecting rod along said guide rail such that said door covering mechanism moves from said third position to said fourth position;
• and
• whereby movement of said casing downwardly along said upright support causes said free end of said push rod to abut against said second contact face of said second lobed part thereby pivoting said elongated first rod in a second direction opposite to said first direction wherein said elongated second rod correspondingly moving said connecting rod along said guide rail such that said door covering mechanism moves from said fourth position to said third position.