Boring bar with reverse mounted insert

A boring bar, comprising:

• a rotary shaft having a rotary axis, a direction of rotation therearound, and a working end;
• said working end including a solid portion and a truncated relief portion, with said solid portion having a relief surface adjacent said relief portion;
• said relief surface having a trailing portion relative to said direction of rotation disposed to one side of said axis and a leading portion disposed laterally opposite said trailing portion;
• a cutting insert;
• and
• said relief surface including cutting insert attachment means having a cutting insert Docket formed therein having a base extending across at least said trailing portion of said relief surface;
• said insert pocket having an upper end and a face defined by a plurality of sides and said base;
• each of said sides of said insert pocket sloping inwardly with respect to said insert pocket face to define an insert pocket upper edge which is narrower than said insert pocket face, for providing a compressive force to said cutting insert installed within said insert pocket for securely holding said cutting insert within said insert pocket;
• cutting insert attachment means disposed within said cutting insert pocket, for removably securing said cutting insert within said cutting insert pocket and for removably attaching said cutting insert thereto and for positioning said cutting insert rearwardly of said solid portion and forwardly of said relief portion relative to said direction of rotation of said rotary shaft;
• said cutting insert having a shape to fit closely within said insert pocket and including an outer face and an inner face wider than said outer face, with a plurality of sloping sides extending between said outer face and said inner face for fitting closely within said inwardly sloping sides of said insert pocket, and a base cutting edge depending at least slightly from said insert pocket and below said working end of said shaft.

A boring bar, comprising:

• a rotary shaft having a rotary axis, a direction of rotation therearound, and a working end;
• said working end including a solid portion and a truncated relief portion, with said solid portion having a relief surface adjacent said relief portion;
• said relief surface having a trailing portion relative to said direction of rotation disposed to one side of said axis and a leading portion disposed laterally opposite said trailing portion, said relief surface having a lower edge defined by a secant of said working end, said lower edge having a forward end and an opposite rearward end;
• and
• said relief surface including a cutting insert pocket formed therein, said insert pocket having an upper end and a face defined by a plurality of sides and a base extending across and a lower outer corner and a lower inner corner at least said trailing portion of said relief surface, each of said sides sloping inwardly with respect to said face to define an upper edge which is narrower than said face, said lower outer corner disposed forwardly of said lower inner corner to define a positive radial rake angle, said insert pocket for removably retaining a cutting insert in a position rearwardly of said solid portion and forwardly of said relief portion relative to said direction of rotation of said rotary shaft and having said positive radial rake angle;
• whereby
• a compressive force is provided by rotation of said shaft which securely holds the cutting insert within said insert pocket.