Power coupling for a chain saw

A power coupling for a chain saw, comprising:

• a housing, said housing comprising two half casings split longitudinally there through;
• power train means for transmitting rotational power through said housing, said power train means including two coupled shafts extending from said housing at right angles to one another;
• a first circular attachment flange concentrically positioned on said housing and fixed thereto about the first of said coupled shafts, said first circular attachment flange being integral with one of said two half casings, said first circular attachment flange including attachment points symmetrically positioned about said flange;
• a second circular attachment flange concentrically positioned on said housing and fixed thereto about the second of said coupled shafts, said second circular attachment flange being integrally formed with the other of said two half casings and said second circular attachment flange including a first attachment surface having radial splines, said second flange including two fastener slots each extending substantially 180 degrees concentrically on said second flange;
• and
• a chain guide plate attachable to a chain saw and having a rotary drive adapted to be powered by a chain and a second attachment surface coaxially arranged with said rotary drive to mate with said first attachment surface for coupling of said rotary drive and the second of said coupled shafts, said second attachment surface having radial spline for interlocking with said radial splines of said first attachment surface and attachment points positioned to meet said fastener slots for retaining fasteners positioned in said slots.