Device For Stabilizing The Course Of The Tunnelling Element

Abstract

A device for stabilizing the course of the tunnelling element, provided with a follow-up unit interacting with the walls of the hole and operating the power units which introduce corrections into the course of the tunnelling element.

Description

This invention relates to the devices for stabilizing the course of the moving tunnelling element and can be used with the self-propelled tunnelling elements and with the driving bits used for making holes in the ground by the compaction method mainly for laying pipes or cables under the surface of highways and railways.

It is known that the tunnelling element can deviate from the preset course owing to heterogeneity of the ground or while encountering solid inclusions or other obstacles.

There have already been attempts to counter this disadvantage by the use of devices which stabilize the course of the moving tunnelling element.

One of these devices comprises some power units with a variable-volume chamber (pneumatic or hydraulic cylinders) which guide the tunnelling element in the right direction, this element having the form of a tapered bit articulated to the front end of the pipe driven through the ground.

The direction of movement in this device is checked with the aid of optical instruments installed immovably in a pit near the mouth of the hole, said instruments registering the deviation of the light ray passing through the pipe from the source of light located inside the driving bit. The optical instruments in this device are linked with the valve mechanisms which control the source into the cylinders guiding the tunnelling element the supply of the fluid medium from in the preset direction (see, for example "Underground laying of pipelines", Mashgiz 1964, G.N. Peskov, page 49).

The known device has a narrow field of application, i.e., only with the driving bits of the pipes forced through the ground. This device cannot be used with more efficient self-propelled tunnelling elements of, say, impact type because the known means of checking the deviation of the tunnelling element cannot be used with this equipment.

Besides, the known devices are complicated in manufacture and operation.

The present invention is intended to eliminate the aforesaid disadvantages.

The main object of the invention is to provide a device for stabilizing the course of the moving tunnelling element with an improved follow-up unit which makes the claimed device suitable for use with various types of the tunnelling elements.

The device described in the invention comprises the power units guiding the tunnelling element, these units having a variable-volume chamber filled with a fluid medium under pressure from the valve mechanisms for guiding the tunnelling element, each of said valve mechanisms being connected with at least one variable-volume chamber and with the instrument registering the deviations of the tunnelling element. The improvement consists in that the follow-up unit is made in the form of a feeler mechanism articulated to the tunnelling element and interacting with the walls of the hole while the valve mechanisms are connected with said feeler mechanism and admit the fluid medium into the corresponding chamber when the feeler mechanism and tunnelling element turn with relation to each other.

It is preferable for the feeler mechanism to be connected with the tunnelling element by an articulated rod and for the valve mechanisms to be mounted directly on the tunnelling element and to be actuated by said articulated rod when it is shifted owing to the turning of the feeler mechanism and tunnelling element.

An advantage of the invention lies in that it uses comparatively simple means for ensuring automatic control of the course of the tunnelling element of any type and for correcting its possible deviations from the preset course.

Now the invention will be described in detail by way of example with reference to the accompanying drawings in which:

FIG. 1 shows the claimed device and the self-propelled tunnelling element turned with relation to each other in the hole;

FIG. 2 is a section taken along line II--II in FIG. 1 showing the arrangement of the variable-volume chambers around the tunnelling element;

FIG. 3 is a section taken along line III--III in FIG. 1 showing the arrangement of the valve mechanisms on the tunnelling element and the articulated rod interacting with the valve mechanisms when one of them is open.

The claimed device comprises a feeler mechanism 1 (FIG. 1) articulated to the tunnelling element 2 and interacting with the walls of the hole 3 made by said element. It is practicable that the tunnelling element 2 be of the pneumatic impact type described in French Pat No. 1,515,348 U.S. Pat. No. 3,580,014 Brit. Pat. Nos. 1,152,249 and 1,170,167, of the authors of the present invention and intended for making holes by compaction of ground.

The feeler mechanism 1 is fastened to the tunnelling element 2 by the articulated rod 4 in such a manner that said mechanism would be able to repeat all the motions of the element 2 in the hole 3.

Equispaced around the tunnelling element 2 are several variable-volume chambers 5, 5a and 5b (FIG. 2) whose walls are made of an elastic rubber-canvas material. These chambers are filled with a fluid medium, e.g., air, under pressure so as to shift the tunnelling element 2 in the required direction.

To prevent the wear of the chambers 5, 5a and 5b caused by friction against the walls of the hole, a cylindrical housing 6 is provided, one end of which is slipped on the tunnelling element 2 in such a manner that said housing can turn with relation to the rounded part 7 of the wider section 8 of the tunnelling element 2 under the pressure of the fluid medium fed into the chambers 5, 5a and 5b.

When the material of the chambers 5, 5a and 5b is sufficiently wear-resistant the housing 6 may be omitted in which case the chambers will be secured directly to the tunnelling element 2.

There is a possibility to substitute said chambers for hydraulic or pneumatic cylinders (not shown in the drawings) located radially with respect to the tail section of the tunnelling element 2.

Each chamber 5, 5a and 5b has an outlet hole 9 and a hose 10 for admitting fluid medium under pressure. Each hose 10 has valve mechanism 11 or 11a or 11b for communicating the corresponding chamber with the source (not shown) of the fluid medium under pressure.

The bodies 12 (FIG. 3) of the valve mechanisms 11, 11a and 11b are secured in the tail section of the tunnelling element 2 while their closing elements 13 are held by the springs 14 in the extreme position, shutting off the supply of the fluid medium, and are in contact with the articulated rod 4, following its motions.

An imperative prerequisite for efficient operation of the device lies in that area of passage through each valve mechanism 11, 11a and 11b and the hoses 10 connected with them should be considerably larger than the area of passage through the outlet holes 9 of the chambers 5, 5a and 5b in order to keep the fluid medium in them under pressure.

The air is fed to the tunnelling element 2 through a hose 15. A hole 17 in the partition 16 of the feeler mechanism 1 lets out the used air from the chambers 5, 5a and 5b and from the tunnelling element 2.

The claimed device functions as follows.

When the tunnelling element 2 moves on the preset course, its axis coincides with that of the feeler mechanism 1 and the rod 4 is positioned either coaxially or parallel with their axes. If the tunnelling element 2 deviates by chance from the preset course its axis is shifted from that of the feeler mechanism 1 and the rod 4 is correspondingly shifted too.

The shifted rod 4 presses the closing element 13 of at least one valve mechanism 11 or 11a or 11b.

As can be seen in FIG. 3, the rod 4 actuates the closing element 13 of the valve mechanism 11a which opens and puts the corresponding chamber 5a (FIG. 2) in communication with the source of fluid medium under pressure.

In view of the fact that the area of passage through the valve mechanism 11a and the admission hose 10 is considerably larger than that of the hole 9 of the chamber 5a, the latter is filled with the fluid medium under pressure. This creates a force shifting the cylindrical housing 6 and producing an additional asymmetry in the resistance to the movement of the tunnelling element so that the latter is correspondingly shifted. The magnitude of this shifting a is shown in FIG. 2.

The trial tests of the claimed device have proved the simplicity of its operation and accuracy of control.

Claims

What is claimed is:

1. A device for stabilizing the course of a tunnelling element comprising: power units interacting with said tunnelling element and provided with variable-volume chambers filled with a fluid medium under pressure for guiding said tunnelling element; a feeler mechanism following the deviations of said tunnelling element, articulating means linking the feeler mechanism to the tunnelling element, said feeler mechanism interacting with the walls of the hole; and valve mechanisms controlling the supply of the fluid medium into said variable-volume chambers, each valve mechanism communicating with at least one of said chambers, said valve mechanisms being connected with said feeler mechanism and admitting the fluid medium into the corresponding chamber when said feeler mechanism and tunnelling element turn with relation to each other.

2. A device as claimed in claim 1 wherein the articulating means between said feeler mechanism and the tunnelling element consists of an articulated rod, and said valve mechanism are located directly on the tunnelling element and are actuated by the rod when the latter is shifted due to relative turning of said feeler mechanisms and tunnelling element.