GB1568575A - Rotary excavating device - Google Patents

Description

(54) ROTARY EXCAVATING DEVICE (71) We, SOLETANCHE, a French Societe Anonyme, of 6, rue de Watford, 92000 Nanterre, France, do hereby declare the invention for which we pray that a patent may be granted to us, and the method by which it is to be performed, to be particularly described in and by the following statement:- This invention relates to machines used for attacking or cutting materials by means of rotary cutter members advancing in a direction perpendicular to their rotational axis. This is the case, for example, with machines used to excavate holes such as wells, mine galleries or trenches in the ground, particulary in hard ground.

One of the disadvantages of known machines of this kind resides in the fact that the parts supporting the rotary cutter members, whether these parts are central or to one side, project, at least partly, in a plane perpendicular to the forward direction of the machine, outside of the working surface of these members.

Consequently, therefore, supplementary work has to be done to clear a passage for these supports and permit the excavation to continue.

For example, in the case of a drilling machine featuring rotary cutter members mounted on one part or another of a common support, such as the machine which forms the object of French Patent Application No. 72.44542 published under number 2,211,027 and of the addition to this application, No. 73.40624 published under number 2,252,011, the presence of the support generally entails the formation, at the bottom of the excavated hole, of a central tongue or ridge which collapses on its own.

However, when it is a matter of more powerful machines in which the motor is spaced from the rotary cutter members and a part of the mechanism transmitting movement to these bits is accommodated in the support, requiring the support to be made more robust and thus increasing the thickness of the tongue or ridge, destruction of the tongue or ridge does not always take place automatically.

The invention has the object of improving machines of the type referred to above, with a view to extending the working field of the excavating members of the rotary cutter members in such a manner that work can continue without obstruction to the advance of the rotary cutter members.

According to the invention there is provided a rotary excavating device comprising an excavating tool-carrying rotor mounted on a support extending transversely to the axis of rotation of the rotor for advance of the rotor in a direction perpendicular to said axis, wherein an excavating tool is movably mounted on the rotor so as to move relative to the rotor between an active position in which its projection, in a plane perpendicular to the direction of advance, overlaps the support, and an inactive position in which it avoids the support.

Maintenance of the tool in the active position may be ensured by any suitable method, for example, by virtue of the reaction of the material being excavated on the tool itself, return to the inactive position being accomplished, for example, by spring means or by contact with a fixed element, such as the support of the rotary member.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a schematic view, in elevation, of a known machine to which this invention can be applied, Figure 2 is a sectional view on a larger scale taken along the line II-II of Figure 3 and showing details of the fitting and the functioning of an excavating tool constructed according to the invention, and Figure 3 is a part-sectional view of Figure 2 in which part of the tool has not been shown.

In the example shown in Figure 1, a drilling machine includes a frame 1 in the shape of an elongated rectangular parallelepiped ending in a relatively thin support 2 situated in the medial plane P of the frame 1 and serving for the fitting of rotary excavating members 3.

The frame 1 contains a motor with a reduction gear assembly, not shown, which drives the members 3 by means of a transmission, for example, by gearing situated in the support 2 and in a gear box 4 integral with this support 2 and on which are mounted the members 3.

The latter are arranged in pairs symmetrical with respect to the medial plane and each comprises a rotor made up of a disc 3a in the shape of a dish which is integral with a central shaft 3b perpendicular to the support and which covers a respective side of the gear box 4, as well as a cylindrical rim 5 which surrounds the gear box 4 and extends to the vicinity of the support 2.

This rim 5 carries the excavating tools which are not shown in the figure but of which the field of operation, as far as conventional tool are concerned, is represented by the rectangules 6 shown in broken lines.

The machine drills a hole 7 in the ground and it can be seen that, if the ground is sufficiently hard, a vertical ridge 8 remains between the two members 3 which, of course after a period of time obstructs the advance of the machine.

With the construction according to the invention shown in Figures 2 and 3, the rim 5 carries, evenly spaced around its periphery adjacent the support 2, cheek plates made up of two brackets 10 and 11 (Figure 3) welded to the rim 5.

These cheek plates run parallel to each other and have coaxial bores 12 and 13 in which a pivot shaft 14 is mounted in a plane perpendicular to the axis of rotation of the rotary member 3 and at a tangent to a circle centred on the said axis.

A tool-bearing element 15 is mounted on the pivot shaft 14 and consists of a solid U-shaped member having a central slot 16 (Figure 3) into which is fitted and welded the shaft 17 of an excavating tool 18. This tool 18 can be of any kind, for example, a pick or a wheel cutter.

The bracket 11 is longer than the other bracket 10 and includes a trapezoidal notch 19 (Figure 2) into which is engaged a laterally projecting portion 20 of the toolbearing element 15.

The arrangement is such thta the tool-bearing element 15 can oscillate between two positions, i.e. that shown in solid lines in Figure 2 in which the projecting portion 20 rests against a face 21 of the notch 19 nearest to the support 2, and that shown in broken lines in which the portion 20 abuts the opposite face 22 of the notch 19. In this latter position the tool 18 is inclined towards the support 2, so that the ground reaction R (Figure 2), which is perpendicular to the rotational axis of the element 3, comprises a longitudinal thrust component L directed towards the axis of the pivot 14 and d tangential component T which tends to cause the tool to swing into the former position, i.e. towards the support 2.

In operation, the tool 18 thus automatically moves into its fully inclined position as a result of this tangential component of force obtained during cutting and it can be seen that, for example, when fitted in the machine shown in Figure 1, the tool 18 can pass very close to the medial plane P of the support and even, if required, can intersect this plane. Thus, the formation of a ridge can be averted or only a thin ridge is formed which collapses as the machine advances.

In the case of a lateral support, it can also be arranged for the tool to pass beyond the projection of the support in a plane perpendicular to the direction of advance.

The return of the tool 18 into the other position (abutting against the face 22) may be effected, for example, by contact of a projection 23 of the shaft 17 of the tool 18 with the support 2 which can be furnished with a suitable ramp or fitting, not shown.

If required, a return spring can be connected to the tool-bearing element 15 with the object of returning it into contact with the face 22.

The use of a spring acting in the reverse direction, i.e. urging the tool-bearing element 15 into an active position towards the face 21 of the bracket slot 19 may also be appropriate in certain cases, with return to wards the face 22 effected by other means, for example by action on the support 2.

It goes without saying that the constructional methods described are only given as examples and that they can be modified, notably by the substitution of equivalent techniques, without departing from the framework of this invention.

WHAT WE CLAIM IS: 1. A rotary excavating device comprising an excavating tool-carrying rotor mounted on a support extending transversely to the axis of rotation of the rotor for advance of the rotor in a direction perpendicular to said axis, wherein an excavating tool is movably mounted on the rotor so as to move relative to the rotor between an active position in which its projection, in a plane perpendicular to the direction of advance,

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (10)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   2 in which part of the tool has not been shown.

   In the example shown in Figure 1, a drilling machine includes a frame 1 in the shape of an elongated rectangular parallelepiped ending in a relatively thin support 2 situated in the medial plane P of the frame 1 and serving for the fitting of rotary excavating members 3.

   The frame 1 contains a motor with a reduction gear assembly, not shown, which drives the members 3 by means of a transmission, for example, by gearing situated in the support 2 and in a gear box 4 integral with this support 2 and on which are mounted the members 3.

   The latter are arranged in pairs symmetrical with respect to the medial plane and each comprises a rotor made up of a disc 3a in the shape of a dish which is integral with a central shaft 3b perpendicular to the support and which covers a respective side of the gear box 4, as well as a cylindrical rim 5 which surrounds the gear box 4 and extends to the vicinity of the support 2.

   This rim 5 carries the excavating tools which are not shown in the figure but of which the field of operation, as far as conventional tool are concerned, is represented by the rectangules 6 shown in broken lines.

   The machine drills a hole 7 in the ground and it can be seen that, if the ground is sufficiently hard, a vertical ridge 8 remains between the two members 3 which, of course after a period of time obstructs the advance of the machine.

   With the construction according to the invention shown in Figures 2 and 3, the rim 5 carries, evenly spaced around its periphery adjacent the support 2, cheek plates made up of two brackets 10 and 11 (Figure 3) welded to the rim 5.

   These cheek plates run parallel to each other and have coaxial bores 12 and 13 in which a pivot shaft 14 is mounted in a plane perpendicular to the axis of rotation of the rotary member 3 and at a tangent to a circle centred on the said axis.

   A tool-bearing element 15 is mounted on the pivot shaft 14 and consists of a solid U-shaped member having a central slot 16 (Figure 3) into which is fitted and welded the shaft 17 of an excavating tool 18. This tool 18 can be of any kind, for example, a pick or a wheel cutter.

   The bracket 11 is longer than the other bracket 10 and includes a trapezoidal notch 19 (Figure 2) into which is engaged a laterally projecting portion 20 of the toolbearing element 15.

   The arrangement is such thta the tool-bearing element 15 can oscillate between two positions, i.e. that shown in solid lines in Figure 2 in which the projecting portion 20 rests against a face 21 of the notch 19 nearest to the support 2, and that shown in broken lines in which the portion 20 abuts the opposite face 22 of the notch 19. In this latter position the tool 18 is inclined towards the support 2, so that the ground reaction R (Figure 2), which is perpendicular to the rotational axis of the element 3, comprises a longitudinal thrust component L directed towards the axis of the pivot 14 and d tangential component T which tends to cause the tool to swing into the former position, i.e. towards the support 2.

   In operation, the tool 18 thus automatically moves into its fully inclined position as a result of this tangential component of force obtained during cutting and it can be seen that, for example, when fitted in the machine shown in Figure 1, the tool 18 can pass very close to the medial plane P of the support and even, if required, can intersect this plane. Thus, the formation of a ridge can be averted or only a thin ridge is formed which collapses as the machine advances.

   In the case of a lateral support, it can also be arranged for the tool to pass beyond the projection of the support in a plane perpendicular to the direction of advance.

   The return of the tool 18 into the other position (abutting against the face 22) may be effected, for example, by contact of a projection 23 of the shaft 17 of the tool 18 with the support 2 which can be furnished with a suitable ramp or fitting, not shown.

   If required, a return spring can be connected to the tool-bearing element 15 with the object of returning it into contact with the face 22.

   The use of a spring acting in the reverse direction, i.e. urging the tool-bearing element 15 into an active position towards the face 21 of the bracket slot 19 may also be appropriate in certain cases, with return to wards the face 22 effected by other means, for example by action on the support 2.

   It goes without saying that the constructional methods described are only given as examples and that they can be modified, notably by the substitution of equivalent techniques, without departing from the framework of this invention.

   WHAT WE CLAIM IS: 1. A rotary excavating device comprising an excavating tool-carrying rotor mounted on a support extending transversely to the axis of rotation of the rotor for advance of the rotor in a direction perpendicular to said axis, wherein an excavating tool is movably mounted on the rotor so as to move relative to the rotor between an active position in which its projection, in a plane perpendicular to the direction of advance,

   overlaps the support, and an inactive position in which it avoids the support.
2. 2. A device according to claim 1, wherein the tool is articulated on the rotor and can pivot between two stops defining the two positions.
3. 3. A device according to claim 2, wherein the pivot axis of the tool is substantially perpendicular to the rotational axis of the rotor.
4. 4. A device according to claim 3, wherein the pivot axis of the tool is tangential to a cylinder coaxial to the rotor.
5. 5. A device according to any one of claims 2 to 4, wherein, in the inactive position, the tool is inclined towards the support, in such a manner that, during excavation, the reaction of the excavated material tends to incline the tool further towards the support to urge the tool into the active position.
6. 6. A device according to claim 5, wherein spring means are provided to return the tool into the inactive position when said reaction is removed.
7. 7. A device according to any one of claims 2 to 4, wherein spring means are provided to urge the tool into the active position.
8. 8. A device according to claim 5 or 7, wherein the tool can be returned to the inactive position by acting on an element fixed relative to the support.
9. 9. A device according to any one of claims 2 to 8, wherein the tool is mounted on a tool-bearing element articulated in a cheek plate which affords stops for a projection provided on the tool-bearing element.
10. 10. A rotary excavating device substantially as hereinbefore described with reference to and as shown in the accompanying drawings.