Engine boring fixture

An apparatus for aligning a center of rotation of a crankshaft of an internal combustion engine block perpendicular to a first direction of motion of a boring tool comprising:

• an elongated engine support means movably mounted on a lower, rigid, support structure;
• said elongated engine support means being operable to move in said first direction or opposite said first direction of motion of the boring tool under control of means for moving;
• whereby said engine support means is operable to support the engine block to be bored at a first and a second selected surface of the engine block so that the center of rotation of the crankshaft of the engine block is substantially perpendicular to the first direction of motion of the boring tool;
• an upper rigid support structure, attached to said lower rigid support structure, and supporting an alignment surface attached thereto;
• said alignment surface defining a plane perpendicular to said first direction of motion of the boring tool;
• said means for moving is adapted to move said elongated engine support means upwardly in order to bring a third selected surface of the engine block into contact with said alignment surface;
• means for sensing adapted to be positionable on said upper rigid support structure and operative to measure a first distance between a first end region of said elongated engine support means and a selected first region of a first end of said upper rigid support structure and a second distance between a second end region of said elongated engine support means and a selected second region of a second end of said upper rigid support structure when the engine block to be bored is supported by said engine support means and when the third selected surface of the engine block is in contact with said alignment surface.

A machine on which the centerline distance, between the crankshaft bearings and the top of an engine block, on either end of the block, may be measured to insure that a cylinder hole to be bored is square with the crankshaft, comprising:

• a housing having a base, a pair of side members perpendicular to said base and a top horizontal member substantially parallel to said base;
• said top member having at least one planar surface selectively located thereon;
• a means for engine block support movably mounted within said housing and operable to support the engine block at a pair of selected support surfaces,
• said means for engine block support including a means for positioning operable to locate a third selected surface of the engine block adjacent and in contact with said planar surface of said top member;
• means for measuring adapted to be positionable on said top member and operative to measure a first and a second distance, said first distance being perpendicularly measured between said planar surface of said top member and said means for engine block support in a region adjacent a first of the selected support surfaces of the engine block,
• said second distance being perpendicularly measured between said planar surface of said top member and said means for engine block support in a region adjacent a second of the selected support surfaces of the engine block.

An engine boring fixture for clamping an engine block whose cylinder or cylinders are to be bored comprising:

• a housing enclosing a central region,
• said housing having a base, a top member and two parallel side members supporting said top member in spaced relation to said base;
• said top member having a planar surface adjacent said central region;
• an engine support cradle having an elongated floor and two parallel sides one affixed to each end of said elongated floor;
• an elongated, rigid, cylindrical engine support bar, capable of substantially supporting an engine block to be bored, by a first and a second crankshaft bearing saddle located respectively at a first and a second end of the engine block;
• said engine support bar having a first and a second end with each of said ends being supported by support means associated with a respective one of said two parallel sides;
• said engine support cradle being supported within said central region by a means for vertical support,
• said means for vertical support being operable to move said engine support cradle, with an engine block to be bored placed thereon, vertically with respect to said planar surface whereby a selected top surface of the engine block, adjacent the cylinder or cylinders to be bored, is brought into contact with said planar surface of said top member;
• means for measuring positionable on said housing and adapted to measure, at each end of the block, a distance proportional to the distance between said planar surface of said top member and a centerline of said cylindrical engine support bar.