Roll flip machine

Apparatus for upending a work piece having a relatively low center of gravity, comprising:

• a base member having forward and rearward portions, supporting first and second horizontal pivot shafts, said first pivot shaft elevated with respect to the center of gravity of said work piece, said first shaft parallel to, elevated with respect to and spaced forward with respect to said second shaft;
• a carriage member pivotally mounted on said first pivot shaft, having the first end of a lever arm mounted thereto and the second end located proximate to said second pivot shaft, said carriage having a base portion being substantially horizontal for supporting said work piece and a back portion being substantially vertical when said carriage is in a first position for loading said work piece, said lever oriented rearwardly at an angle of approximately 45.degree. with respect to vertical when said carriage is in said first position for loading said work piece;
• a linear driving means having a housing with a forward end proximate to said lever arm pivotally mounted on said second pivot shaft, said housing containing a linear driving member oriented substantially horizontally when said carriage is in said first position, having a force transmitting end pivotally connected to said second end of said lever arm, for applying a forwardly directed driving force;
• said linear driving means forcing said second end of said lever forward, rotating said carriage into a second position where said base portion is substantially vertical and said back portion is substantially horizontal, lifting the center of gravity of said work piece above the elevation of said first pivot shaft, upending said work piece, said lever oriented forwardly at an angle of approximately 45.degree. with respect to vertical when said carriage is in said second position, said second end of said lever describing an arc about said first pivot shaft during the motion of said carriage from said first to said second position, causing said housing to rotate about said second pivot shaft to enable said linear driving member to form an approximately tangential angle with respect to said arc described by said second end of said lever during the early portion of the actuation of said linear driving means;
• whereby a greater driving torque may be applied to said carriage by said linear driving means during the early portion of the actuation thereof more closely matching the driving torque capacity of the linear driving means to the load torque requirements of upending a work piece with a center of gravity at an initial lesser elevation than said first pivot shaft.