DRILLING MACHINE Russian patent published in 2003 - IPC

FIELD: instrumentation engineering, applicable in medical technologies for prosthetics and treatment of teeth. SUBSTANCE: drilling machine has drive with shaft having output end with axial hole, sleeve with bottom having hole coating to hole of shaft output end and rigidly secured to shaft output end, two helical springs for clamping of shank of cutting tool and located in sleeve cavity. Diameters of holes of sleeve bottom, shaft output end and inner diameter of the first helical spring are made to outer diameter of cutting tool shank. Similar ends of helical springs have lugs for their locking from turning. Drilling machine has additional second helical spring made of wire with diameter smaller than diameter of wire of the first helical spring and with inner diameter smaller than outer diameter of cutting tool shank. Coils of one helical spring are located between coils of other helical spring, and spring lugs are secured in region of sleeve bottom of shaft output end. Initial coils of helical springs on side of their lugs have diameter equaling that of internal cavity of sleeve of shaft output end. Sleeve bottom is made removable in form of cap, and lugs of helical springs are of hook shape and located in groove provided in sleeve on line of cap joint line. EFFECT: higher operating characteristics of drilling machine due to excluded falling-out of cutting tool with no load (torque). 3 cl, 2 dwg