| 摘要 |
The invention concerns a rake drill bit consisting of body, whose upper part is welded to joining element with section of drill lead and lower part is equipped with elements cutting with teeth symmetrically located on body's circumference along its axis, where is situated central flow canal, characterised in that body (1) has diameter greater than diameter of drill lead and is equipped with in even number of suction pipes (8) spaced evenly on body's (1) circumference, above cutting elements (3), and angle between axis of body (1) and of each suction pipe (8) is 25 degrees, and suction pipes (8) are limbs of central flow canal, at inlet of which is located crowns (6) precluding circulation of drillings and drilling fluid, fixed to body (1), whereas inlet planes (9) of tips, preferably replaceable, of suction pipes (8) form with axis of suction pipes (8) angle 30 degrees - 45 degrees, and sum of surfaces of cross-section of suction pipes (8) is not lesser than surface of cross-section of drill lead, with cutting elements (3) being connected to bracket ring (7) located on body (1).<IMAGE>
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