Machine tool, comprising a base (1) with a bottom (10) and a peripheral wall (11) of predetermined height to delimit an internal volume of predetermined capacity and open at the top, in which on the upper edge of said wall (11) is placed, removably, a pierced cover (2), or a work-piece carrier surface provided with through holes (20) through which a refrigerant liquid is free to fall, and wherein an electric motor (4), on which is engaged a tool holder (7), is placed in said inner volume, and wherein said electric motor (4) is inserted in a protection chamber (5) which protects it from the refrigerant liquid passing through said holes (20). The electric motor (4) is connected to corresponding lowering and lifting means, by means of which the tool holder (7) is lowered and raised accordingly, so producing the lifting and lowering of a respective tool (3) through the cover (2).

A broaching tool, comprising a shank, a body and a cutting head that comprises at least one rake face. The rake face comprises a cutting edge that comprises a cutting corner at a forward end of the cutting head. The rake face is configured such that upon simultaneously rotating the broaching tool about the axis of the broaching tool and advancing the broaching tool along the axis of the broaching tool in a forward direction, the first corner travels in a first circular helix pattern. Also, a method of forming one or more grooves in a bore-containing structure, the method comprising simultaneously rotating a broaching tool and a bore-containing structure relative to one another about the axis, and moving the broaching tool and the bore-containing structure relative to one another along the axis. Also, methods of making broaching tools, and broaching machines.

A broaching tool, comprising a shank, a body and a cutting head that comprises at least one rake face. The rake face comprises a cutting edge that comprises a cutting corner at a forward end of the cutting head. The rake face is configured such that upon simultaneously rotating the broaching tool about the axis of the broaching tool and advancing the broaching tool along the axis of the broaching tool in a forward direction, the first corner travels in a first circular helix pattern. Also, a method of forming one or more grooves in a bore-containing structure, the method comprising simultaneously rotating a broaching tool and a bore-containing structure relative to one another about the axis, and moving the broaching tool and the bore-containing structure relative to one another along the axis. Also, methods of making broaching tools, and broaching machines.

Stepped rotary broaches, and systems and methods employing such broaches, are disclosed herein. In one example embodiment, a stepped rotary broach includes a contact portion integrally formed with or coupled to a support portion. The contact portion includes a face and a periphery. The periphery includes an outer surface and a plurality of step formations, where each of the step formations extends between the face and a respective location along the periphery at which the respective step formation adjoins a respective portion of the outer surface. Each of the step formations includes a respective step including a respective surface region extending in a respective direction about a central axis of the stepped rotary broach. The respective surface regions of the respective steps are respectively positioned more closely to the central axis than are the respective portions of the respective outer surface that respectively adjoin the respective step formations.

Stepped rotary broaches, and systems and methods employing such broaches, are disclosed herein. In one example embodiment, a stepped rotary broach includes a contact portion integrally formed with or coupled to a support portion. The contact portion includes a face and a periphery. The periphery includes an outer surface and a plurality of step formations, where each of the step formations extends between the face and a respective location along the periphery at which the respective step formation adjoins a respective portion of the outer surface. Each of the step formations includes a respective step including a respective surface region extending in a respective direction about a central axis of the stepped rotary broach. The respective surface regions of the respective steps are respectively positioned more closely to the central axis than are the respective portions of the respective outer surface that respectively adjoin the respective step formations.

Machine tool, comprising a base (1) with a bottom (10) and a peripheral wall (11) of predetermined height to delimit an internal volume of predetermined capacity and open at the top, in which on the upper edge of said wall (11) is placed, removably, a pierced cover (2), or a work-piece carrier surface provided with through holes (20) through which a refrigerant liquid is free to fall, and wherein an electric motor (4), on which is engaged a tool holder (7), is placed in said inner volume, and wherein said electric motor (4) is inserted in a protection chamber (5) which protects it from the refrigerant liquid passing through said holes (20). The electric motor (4) is connected to corresponding lowering and lifting means, by means of which the tool holder (7) is lowered and raised accordingly, so producing the lifting and lowering of a respective tool (3) through the cover (2).