Patent ID: 8256533

Claim:
A distance holder for connection to, and rotation with, a drill string in an earth formation drilling device arranged to supply a jet of abrasive fluid for the purpose of providing a borehole by removing earth formation material through abrasion, comprising a housing with a chamber that is essentially rotationally symmetric and has a rotation axis and which faces the earth formation material, and a jet nozzle arranged for discharging a jet of the abrasive fluid in said chamber, said housing comprising at least one slot for allowing the abrasive fluid to leave the chamber, wherein the slot is continued over the outer surface of said housing, and wherein the housing at its axially outermost end comprises a skirt having an outer surface, the slot being provided in said skirt, wherein the slot extends helically on the outer surface of the skirt wherein the skirt is provided with a deflector positioned in the path of the fluid jet discharged from the jet nozzle; and wherein a distance from the side of said deflector bordering the slot to the rotation axis is larger than a distance from the opposite side of said deflector to the rotation axis, such that said deflector has a slanting orientation that diverts the fluid jet toward the slot.