Method Of Reaming Ground Through Holes And Device For Effecting Same

Abstract

A method of reaming through holes by destroying the soil layers adjacent to the hole, and a device for effecting this method, in which the reamer is provided with means used for destroying in the hole the adjacent layers of the soil.

Description

The present invention relates to methods of reaming ground through-holes, and to devices for effecting these methods.

At present, widely known in the art is a method of reaming preliminarily formed through-holes by double packing adjacent layers of the soil, as a result of which the holes are reamed to a required diameter. Usually, the packing is not carried out more than two times, since further packing is generally inefficient and requires much energy.

The above method is disadvantageous in that the formation of holes of large diameters may bring about bulging which may result in destruction of constructions, such as railway tracks or highways, disposed thereabove. Experiences show that the above-described method can be applied only in the cases when the diameter of the hole does not exceed 400 mm.

Additionally, the prior art method of forming reamed holes by packing consumes large quantities of energy, and therefore requires use of powerful devices.

In order to carry out the method of reaming holes by packing, use is generally made of devices statically of the following two types: devices acting upon the ground and those dynamically acting upon the ground.

In both cases the working member (tool) of the device is essentially a reamer, i.e., a conically-shaped body.

In the static-action device the reamer is drawn through a hole by means of jacks acting on the reamer through the intermediary of rods.

Also known in the art are static-action devices having a reamer which is drawn through a hole by means of a hoist.

These devices are disadvantageous in that they are generally inefficient and require large quantities of energy.

The devices that act upon the ground dynamically incorporate essentially a percussive mechanism in which a reamer is mounted in the head portion thereof. Under the action of an impact impulse the devices are moved forwardly and their reamer moves the soil aside, thereby reaming the hole.

All the afore-described devices can be used only for carrying out methods of reaming holes by packing the soil.

It is an object of the present invention to eliminate the disadvantages of the conventional method of reaming holes through provision of an improved and novel reaming method, and to provide a device for carrying out the improved method.

Accordingly, a primary object of the present invention is to provide a method of reaming holes, which is based on the principle of removal of the soil from the hole rather than on the principle of packing the soil adjacent to the hole, and furthermore provides for a device for carrying out the inventive method.

This object is accomplished in that the method of reaming ground through-holes, according to the invention, consists of in that the soil layers adjacent to the hole are destroyed simultaneously with the blowing-through of the hole in the direction in which it is being reamed.

In order to carry out the method with the device for reaming ground through holes, the device is essentially a body which is moved through the hole by means of a drive, and includes a reamer mounted at the head portion thereof. In accordance with the invention, the walls of the reamer constitute a lattice and form in the tail portion of the reamer a chamber which is connected with a compressor, being provided at the front portion thereof with a nozzle.

It is expedient to construct the lattice walls of the reamer from rings-cutters of different sizes, which are arranged one after another as their diameters increase, and which are interconnected by ribs.

In order to protect the rings against boulders or other encountered obstacles which cannot be packed, the ribs interconnecting the rings-cutters are disposed in such a manner so as to protrude outside relative to the rings.

In view of this embodiment of the ribs, the afore-mentioned obstacles or boulder are moved aside during operation of the device.

In order to prevent the nozzle passage from being clogged, and to provide for a more effective destruction of the soil cuttings, a disc accommodating nozzles which are built therein, mounted tangentially and inclined in the direction of the nozzle of the reamer, is installed within the chamber of the reamer, and is adapted to be freely rotated.

To preclude an emergency increase of pressure in the chamber in the case the passage of the preliminary holes is completely clogged, the face wall of the reamer is made from an elastic material and is provided with a cut which forms an orifice during the course of any face wall deformation.

The following detailed description of exemplary embodiments of the present invention is given with reference to the accompanying drawings in which:

FIG. 1 shows a ground through-hole reamed for a portions of its length by the method according to the invention;

FIG. 2 shows a longitudinal sectional view of a first embodiment of the device for reaming the hole by the method according to the invention;

FIG. 3 is a section taken along line III in FIG. 2;

FIG. 4 is a section taken along line IV--IV in FIG. 2;

FIG. 5 shows a longitudinal sectional view of a second embodiment of the device for effecting the method of reaming the hole according to the invention; and

FIG. 6 is a section taken along line VI--VI in FIG. 5.

The method according to the present invention is adapted for reaming through-holes which are preliminarily formed by any conventional method and by means of any conventional device.

Holes may be reamed with any of the below-described devices.

Due to the fact that the reamer of each of these devices is provided with lattice walls, the soil is destroyed as the reamer advances along the hole and, through the orifices of the reamer, is conveyed into the chamber of the latter. Particles of the ground soil within the chamber of the reamer are then carried away from the hole by an air flow generated by the compressor and which directed along the hole being reamed.

In order to keep the particles of the ground soil in a loose or suspended state, the speed of the air flow must be maintained sufficiently high.

In practice, the method can be applied to the reaming of holes in any soil, in a coal seam, or the like.

FIG. 2 shows an embodiment of the device designed for carrying out the method according to the invention.

The device comprises a percussive mechanism 1 consisting of a body 2 with a percussor (not shown in the drawing) movable within the body; and a reamer 3 secured to the front portion of the body 2 of the percussive mechanism 1.

The reamer 3 is formed by ring-shaped cutters 4 of different diameters, arranged one after another as their diameters increase. The cutters 4 are interconnected by ribs 5 which are secured by means of a coupling 6 (FIG. 2) on the body 2.

The ribs 5 are made so that they protrude outside relative to the cutting edges of the cutters 4. Because of this construction, in case the reamer encounters a boulder or some other obstacle that cannot be ground or packed, the latter is moved aside by the inclined surfaces of the ribs 5.

At its front or leading end portion the reamer 3 is provided with a nozzle 7, and at its trailing end portion it is connected, by means of a shell 8, with a chamber 9 into which compressed air is supplied from a compressor (not shown in the drawing) through a pipe line 10. Mounted on the pipe line 10 is a support valve 11 which distributes the supply of the compressed air into the body 2 of the mechanism 1 and inside the chamber 9. The compressed air used by the mechanism 1 is also delivered into the chamber 9.

Mounted so as to be capable of free displacement within the shell 8 is a disc 12 with nozzles 13 which are disposed tangentially and are inclined relative to the nozzle of the reamer 7 (FIGS. 2 and 3).

The face wall 14 of chamber 9 is made of an elastic material, such as rubber. An emergency pressure rise within the chamber 9 caused by the clogging of the passage of the nozzle 7 or of the preliminary hole 15 formed in the ground as shown in FIG. 1, causes deformation of the wall 14, as a result of which a clearance is formed between the wall and the walls of the cut through which the pipe line 10 is laid, so as to thereby vent the compressed air into the atmosphere through the reamed hole 16.

The device functions as follows:

The nozzle 7 of the device is brought into the preliminarily formed hole 15 as shown in FIG. 1, and which extends between two end shafts 15' sunk into the ground.

With the compressed air being conveyed through the pipe line 10, the mechanism 1 starts delivering blows against the reamer 3, thus providing for advancement of the device along the hole. With the device advancing, the adjacent layers of the soil are cut off by the annular cutters, the soil passes through the lattice walls of the reamer, and is then ground and carried away to the outside by the air flow along the preliminary hole 15 through the nozzle 7. This forms the enlarged diameter bore hole 15", as shown in FIG. 1 of the drawings, having a diameter commensurate with the external diameter of the device.

WIth the air flow generated by the compressor, because of the nozzles 13 being arranged in the afore-described manner, the disc 12 rotates, thus creating narrow air streams. This contributes to an additional crushing of the soil cuttings, and provides for a more effective removal of the soil particles.

The friction forces arising between the surface of the shell 8 and the soil protect the device in the hole against the action of inertial forces.

FIG. 5 shows another embodiment of the device for reaming holes through the method according to the present invention.

The device comprises a percussive mechanism 17 consisting of a body 18 with a percussor (not shown in the drawing) being movable within the body; and with a reamer 19 being secured on the front portion of the body 18 of the percussive mechanism 17.

The reamer 19 is made integral with a chamber 20 and is provided at the front portion thereof with a nozzle 21. The walls of the reamer and nozzle are provided with orifices 22 (FIGS. 5,6) and 23 (FIG. 5), respectively.

By means of ribs 24 the reamer 19 and chamber 20 are secured to a coupling 25 which, in turn, is mounted on the front portion of the body 18 of the percussive mechanism 17.

The face wall 26 of chamber 20 is made in a manner analogous to that described with reference to the first embodiment of the device and has an analogous designation.

Compressed air is delivered into the mechanism 17 through a hose 27, and into the chamber 20 through a hose 28.

In general, the device operates in a manner analogous to that of the device of the first embodiment. As the device advances, the adjacent layers of the soil are pushed through the orifices 22, and soil particles 29 are conveyed to the outside by the compressed air along the preliminary hole 30. The orifices 23 of the nozzle 21 are designed to prevent packing of the soil disposed ahead of the reamer 19.

Claims

What we claim is:

1. A device for reaming ground through holes by destroying the soil layers adjacent to the hole simultaneously with the blowing-through of said hole in the direction of its reaming, comprising a body; a drive for displacing said body through said hole; a reamer mounted at the leading end portion of said body and having lattice walls; said walls of said reamer forming at the trailing end portion thereof a chamber; a compressor communicating with said chamber;and a nozzle being provided at the leading end of said reamer.

2. A device according to claim 1, in which a disc accommodating nozzles built therein, mounted tangentially and inclined in the direction of said nozzle of said reamer, is installed inside said chamber of the reamer capably of rotating freely.

3. A device according to claim 1, in which the face wall of said chamber of said reamer is made from an elastic material and is provided with a cut which in the course of the face wall deformation forms an orifice.

4. A device according to claim 1, in which the walls of said reamer are formed by a system of rings-cutters of different sizes, arranged one after another as their diameters increase and interconnected by ribs.

5. A device according to claim 4, in which said ribs interconnecting said rings-cutters protrude outside relative to said rings.