Boring unit, in particular for small and middle depths

Claim 2

A boring unit, in particular for small and middle depths including: a substantially cylindrical body hanging from a hoisting apparatus and adapted to be lowered into a borehole; rotary drilling means provided at the end of said cylindrical body and including boring crowns, at least one of which has its teeth directed towards the inlet of said borehole; electrical and hydraulic means mounted in said cylindrical body for driving the said rotary drilling means in rotation relative to said cylindrical body; bar means actuated by said hoisting apparatus for axially lowering said cylindrical body while axially driving said rotary drilling means into said borehole; means carried by said hoisting apparatus for axially guiding said bar means while holding the latter against rotation, the said bar means being solid with said cylindrical body in rotation as well as in translation; and means for recovering the drilling waste from said borehole.

Claim 3

A boring unit according to claim 1, wherein the said means for holding the said bar means against rotation include a fixed plate provided with an opening of polygonal section through which the said bar means are adapted to slide, the said bar means having a similar corresponding cross section.

Claim 4

A boring unit according to claim 1, wherein the said hoisting apparatus is mounted on a truck provided with a crane adapted to the position the said bar means upright with respect to the borehole.

Claim 5

A boring unit according to claim 1, wherein said electrical and hydraulic means include a hydroelectric set with an electric motor which drives a hydraulic pump feeding at least one hydraulic motor adapted to rotate said rotary drilling means, and an auxiliary pump for the circulation of the drilling mud.

Claim 6

A boring unit according to claim 1, wherein the said means for recovering the waste or spoils comprise successive settling tanks constituted by buckets or vats which can be loaded onto a lorry.

Claim 7

A boring unit, in particular for small and middle depths including: a substantially cylindrical body hanging from a hoisting apparatus and adapted to be lowered into a borehole; rotary drilling means provided at the end of said cylindrical body; electrical and hydraulic means mounted in said cylindrical body for driving the said rotary drilling means in rotation relative to said cylindrical body, said electrical and hydraulic means comprising a hydroelectric set with an electric motor which drives a hydraulic pump feeding at least one hydraulic motor adapted to rotate said rotary drilling means, and an auxiliary pump for the circulation of the drilling mud; bar means actuated by said hoisting apparatus for axially lowering said cylindrical body while axially driving said rotary drilling means into said borehole; means carried by said hoisting apparatus for axially guiding said bar means while holding the latter against rotation, the said bar means being solid with said cylindrical body in rotation as well as in translation; with said hoisting apparatus including drum means around which an electric supply cable for said electric motor and a flexible pipe for conveying said drilling mud to said rotary drilling means, are wound; and means for recovering the drilling waste from said borehole.

Claim 8

A boring unit, in particular for small and middle depths including: a substantially cylindrical body hanging from a hoisting apparatus and adapted to be lowered into a borehole; rotary drilling means provided at the end of said cylindrical body; electrical and hydraulic means mounted in said cylindrical body for driving the said rotary drilling means in rotation relative to said cylindrical body, said electrical and hydraulic means comprising a hydroelectric set with an electric motor which drives a hydraulic pump feeding at least one hydraulic motor adapted to rotate said rotary drilling means, and an auxiliary pump for the circulation of the drilling mud; bar means actuated by said hoisting apparatus for axially lowering said cylindrical body while axially driving said rotary drilling means into said borehole; means carried by said hoisting apparatus for axially guiding said bar means while holding the latter against rotation, the said bar means being solid with said cylindrical body in rotation as well as in translation; with said hoisting apparatus including drum means around which an electric supply cable for said electric motor and a flexible pipe for conveying said drilling mud to said rotary drilling means, are wound; and means for recovering the drilling waste from said borehole.

Claim 9

A boring unit according to claim 6, wherein the said means for holding said bar means against rotation include a fixed plate provided with an opening of polygonal section through which the said bar means are adapted to slide, said bar means having a similar corrEsponding cross section.

Claim 10

A boring unit according to claim 6, wherein said hoisting apparatus is mounted on a truck provided with a crane adapted to position said bar means upright with respect to said borehole.

Claim 11

A boring unit according to claim 6, wherein said rotary drilling means include boring crowns, at least one of which has its teeth directed towards the inlet of the borehole.

Claim 12

A boring unit according to claim 6, wherein said means for recovering the waste comprise successive settling tanks constituted by buckets which can be loaded onto a lorry.