Assembly for moving excavation or drilling equipment and actuating method therefor

An assembly for driving excavating equipment for an excavating machine includes a drive assembly sliding along a mast of a machine, for driving the drilling equipment; and an actuator. The drive assembly includes a first structure with guide members for sliding along the mast; and a second support structure to support the drilling equipment. The first and second support structures are mutually movable. The drive assembly has at least two operating configurations, for setting at least two excavation center-to-center distances. In the operating configurations of the drive assembly, the first and second support structures are mutually rigidly and directly constrained. While switching between operating configurations, the first and second support structures are always directly mechanically constrained to each other. The actuator controls movement between the first structure and the second support structure and carries out further operative functions for driving parts of an excavating machine or drilling equipment.

This application is a National Stage Application of International Application No. PCT/IB2019/050288, filed Jan. 15, 2019, which claims benefit of Serial No. 102018000001088, filed Jan. 16, 2018 in Italy and which applications are incorporated herein by reference. To the extent appropriate, a claim of priority is made to each of the above-disclosed applications.

TECHNICAL FIELD

The present invention finds application in the field of drilling techniques, and relates to an assembly, comprising a drive assembly and an actuator, for driving parts of ground drilling equipment. The present invention further relates to a system comprising such an assembly, adapted to allow changing the excavation centre-to-centre distance in an excavating machine.

Furthermore, the present invention relates to a method for changing the excavation centre-to-centre distance in an excavating machine.

TECHNOLOGICAL BACKGROUND/STATE OF THE ART

It is known that the procedures for making a foundation or ground consolidation excavation rely mainly on a self-moving machine, generally a tracked one, equipped with a rotating tower, also called “upper-structure” or “upper-frame”, which comprises an operator cabin and the propulsion and control units used for the driving and drilling operations. A mast is connected to the rotating tower with one or more degrees of freedom, in particular directly to the frame of the rotating tower or to a telescopic movable part projecting out from the frame and sliding thereon towards the excavation, referred to as “spotter frame”, or through more or less complex linkages, which allow adjusting the spatial position of the mast, thus allowing the mast to take different angles and/or to move closer to or farther from the rotating tower. The mast comprises a power assembly and ground excavating means. The mast is an elongated boxed-type or lattice-type element. Said mast is delimited at the top by a head and at the bottom by a foot adapted to transmit to the ground a part of the loads acting upon the structures. The power assembly, which may be either hydraulic or electric, is also called drill head or “rotary”. The rotary moves along said mast between the head and the foot, transmitting the rotatory motion and a forward or upward force to excavating or drilling means or tools. The excavating means in turn comprise: a drill rod, which may be either simple or telescopic, also referred to as “kelly”; and an excavating or consolidating tool. The excavating means may be mounted slideable relative to the rotary and may be equipped with suitable independent driving means.

For the purposes of the present description, said excavating means are defined as excavating equipment.

The driving means for the rotary and the excavating means, employed for ensuring a constant thrust on the excavating tool and/or for extracting the drill string when the excavation is complete, are substantially of two kinds:driving systems with flexible elements: rope-type hoist or chain-type motoreducer;rigid driving means: e.g. operated by means of a hydraulic cylinder.

The driving means with flexible elements, more specifically rope-type driving means, require the application, on the machine or directly on the mast, of one or more hoists comprising a drum around which a rope is wound. Pulls may be either direct or “multiplied” by means of transmission systems, in which case the insertion/extraction force will be increased at the cost of a lower speed of the excavating means.

Rigid driving means mostly consist of linear actuators or cylinders arranged on the front side of the machine, or excavation side. Said linear actuators are fastened at one end to the mast, and are connected at the other end to the rotary in order to transmit thereto the push and pull forces while moving it longitudinally, guided by the mast.

The rotary is normally installed on the mast with an excavation axis located at a predefined distance from the mast guides, on which the rotary slides longitudinally. The distance of the excavation axis of the rotary from the mast guides depends on the dimensions of the guiding means on the mast, of the driving means along the rotary tower, and of the power means for turning the excavating tools. Such distance is generally known as “excavation centre-to-centre distance”. As a function of the excavation centre-to-centre distance it is possible to define the loads acting upon the structures, particularly upon the mast, and the general stability of the excavating or drilling machine.

Given an excavation centre-to-centre distance, the maximum diameter of the excavating tool that can be used and driven in front of the mast must be smaller than or equal to twice the value of the excavating centre-to-centre distance, in order to avoid that the excavating tool might come in contact with the mast or with the means installed thereon, such as, for example, ropes, pulleys, fittings, which generally protrude past the mast structure.

In the course of time, however, the increasing power of the motors installed on the self-moving rotating towers, or externally supplied to such rotating towers, and the increasing torque outputs of the rotaries installed on machines of the same size or category, have made it possible to increase the drilling diameters, resulting in a fresh need for arranging the excavating equipment at longer excavation centre-to-centre distances, so as to allow drilling while at the same time ensuring the necessary stability of the machine.

Patent EP 0,433,892 describes excavating or drilling machines equipped with a parallelogram-type linkage. In these machines, the guiding mast is connected to the tower through an articulated quadrilateral that can be moved by means of a motor unit. The elements connected to the frame rotate about pins. In this solution, the mast translates without rotating, keeping its own inclination unchanged throughout the movement.

The parallelogram-type linkage is conveniently used in order to change the excavation radius, i.e. the distance between the excavation axis and the axis of rotation of the tower on the tracked carriage, by a very high value, even more than one metre. In this solution, when the working radius is at its minimum the mast is close to the rotating tower and in a raised position. Conversely, when the working radius is at its maximum, i.e. in the fully extended position, the mast translates forwards and goes down, moving away from the tower and dropping towards the ground.

Conveniently, in the configuration with the minimum working radius it is possible to use the room under the mast to install a tool having a very big diameter, which could not otherwise be installed in front of the mast. However, this simple solution is not applicable when, instead of using a drill bit of a mechanical mixing tool, the tool to be used has a cylindrical stem equipped with an openable base, called bucket, because the height between the mast and the ground may nevertheless be insufficient to allow the base to open and discharge the material excavated from the borehole.

Another condition that poses a diameter limitation is found in the so-called “segmental casing” applications, wherein the casing elements may have considerable longitudinal dimensions, even as long as 6 m, to allow for an advantageous reduction of the excavation times. As in the previous case, in this case as well the rod will have a maximum diameter compatible with the excavation centre-to-centre distance, since it will inevitably end up operating in front of the mast.

It is therefore advantageous, in such cases, to move the excavation axis away from the mast, so that bigger tool diameters can be used.

EP 0,548,900 teaches to change the excavation centre-to-centre distance in a mechanized way in a mobile drilling rig for hydrocarbon exploration, by using a kinematic connection between the rotary and the rotary support carriage sliding in a guided manner along the mast. Said connection is an articulated quadrilateral that causes the rotary to translate from a first retracted working position to an extended service position for picking up the drill rods to be added to the string. Several drawbacks make this solution unsuitable for applications wherein drilling machines are used for building foundation piles, particularly piles having considerable dimensions. Such drilling machines for hydrocarbon exploration as described in the above-mentioned patent are different, in that they utilize much smaller drill rods and tools, generally a few hundred millimetres in diameter. Moreover, the loads that stress the structures while raising a drill rod as described in said patent are much smaller than those generated during the working or excavation phase. Besides, in the application described in said patent there are no vibrations and fatigue loads that might result in an unstable connection between the rotary and the mast. Furthermore, the linkage is bulky, heavy, and reduces stability, in addition to being complex and expensive. Also, the solution described in said patent requires the use of a dedicated actuator, exclusively adapted to drive said linkage, being connected to the carriage and to the linkage itself. The presence of an additional actuator implies higher costs and more maintenance, and also requires the implementation of a power supply for the actuator in order to impart the movements.

According to other solutions employed in this field, the rotary is mounted on a guiding structure or carriage that can be replaced in order to adapt it to the centre-to-centre distance. In practice, in order to obtain a shorter excavation centre-to-centre distance a first type of carriage is mounted, which protrudes only slightly from the mast; whereas to obtain a longer excavation centre-to-centre distance a second type of carriage is mounted, which protrudes more from the mast.

As an alternative, one type only of carriage is used, to which a spacer can then be added between the carriage and the rotary in order to move the rotary away from the mast.

These solutions offer the advantage that they provide a rigid connection between the rotary and the carriage, without the interposition of any kinematic elements. Direct connections are therefore used, by means of pins or screws. On the other hand, however, the centre-to-centre distance cannot be changed easily and quickly. In order to implement these solutions, in fact, time-consuming and difficult operations are necessary for dismounting the rotary, which must be completely released or disconnected from the carriage, and for substituting the carriages, which generally also carry connection and transmission means for drive units and hydraulic components. By way of example, reference can be made to patent EP 1,983,149, wherein some solutions are disclosed for facilitating the mounting and dismounting of the rotary in transport conditions, so that the person skilled in the art can understand the complexity of the operations required for dismounting the carriage, on which there are many elements such as pulleys, ropes and hydraulic units.

With reference toFIG. 1, there is shown a drilling machine100according to the prior art, which comprises a rotating tower1comprising: a base frame connected to an undercarriage2through a vertical-axis rotation centre plate; suitable drive motor means; a cabin with a control seat, from which the operator carries out the positioning checks and the excavation operations; power and control assemblies, contained in suitable compartments, for supplying primary power, whether hydraulic or electric, to the machine; one or more ballast elements, arranged in the rear, for stabilising drilling machine100.

Said self-moving tracked undercarriage2is driven by rotating tower1through a connection joint.

Drilling machine100further comprises a connection linkage3between a mast5and rotating tower1; said linkage3allows mast5to be moved in space with at least one degree of freedom, preferably by rotating and translating relative to the base frame. In particular, said linkage3is an articulated quadrilateral made up of two elements connected to the base frame of rotating tower1and at least one linear actuator, e.g. a hydraulic cylinder, that connects the base frame of rotating tower1to one of the other elements of the articulated quadrilateral. An upper support element of linkage3is connected to mast5through a pin-type connection that allows mast5to rotate from a transport configuration, in which mast5is substantially horizontal, to a working configuration, in which mast5is substantially vertical. Rotation of mast5is imparted by a pair of hydraulic jacks that connect mast5to the upper element of linkage3. Said pair of jacks also allow mast5to rotate transversally, in addition to longitudinally, through a different modulation of the opening thereof. This results in four tilting adjustments, i.e. frontal and lateral, of mast5.

Said mast5consists of one or more central members, and is connected at the top to a head6that supports the pulleys adapted for the sliding of a main rope23a. Said main rope23ais normally used for moving a drill rod or kelly10, or for moving a continuous flight auger or CFA drill head or rotary8, in case of drilling without a kelly10. The pulleys of head6are also adapted for the sliding of a service rope23b, which is used for moving the loads and equipment useful for preparing the drilling process. To the base of mast5a bottom foot7may be connected, which generally carries an internal hydraulic cylinder that, by extending itself, causes a support plate connected to the end thereof to go down to ground “G”. Said bottom foot7is used in order to give stability to the machine and to be able to exert the maximum extraction forces, particularly in cased drilling operations, e.g. comprising an outer casing protecting the walls of the borehole, and for other excavation technologies, such as, for example, continuous flight auger drilling, also referred to as CFA. On mast5there is a third hoist13, called pull-down hoist, which is used for moving rotary8. Two branches of a rope are connected to rotary8, at the top in order to exert an extraction or pull force, and at the bottom in order to exert an insertion or push force on the excavation tools. The rope may be either connected directly to rotary8or applied onto a sliding carriage9.

Said rotary8is adapted to slide along mast5through mechanical guiding or countering means, which allow for the guided sliding thereof along mast5. These guiding or countering means may be connected to rotary8in a non-removable manner, or may be connected in a removable manner on a distinct component defined as rotary carriage9. Said rotary carriage9is adapted to support the driving means, e.g. the connections for pull and/or push ropes, or transmission pulleys in case of multiple-tackle pulls, which allow reducing the dimensions of pull-down hoist13. Said guiding or countering means are, for example, guiding sliders or, as an alternative, rollers. Normally rotary carriage9is employed on drilling machines100when it is necessary to remove rotary8from mast5, e.g. in transport conditions, in order to reduce the total weight of the machine. In this case, the connection between the carriage and the rotary is effected by means of removable connections, and only one operating configuration can be taken, which defines a single excavation centre-to-centre distance.

Said drill rod or kelly10, e.g. a telescopic rod with multiple elements that can run one into the other as shown inFIG. 1, is slideably connected inside rotary8and is moved by the main hoist, the end of which is connected to the innermost drilling member, generally through the interposition of a swivelling element. The main hoist may be installed either on rotating tower1(as inFIG. 1) or on mast5, just like pull-down hoist13. When the rope of the hoist is released, kelly10goes down until the outer member abuts against rotary8, while the inner members continue to descend under their own weight. When the rope is pulled, the members are compacted, thus extracting kelly10from the borehole. Rotary8can exert a thrust force on kelly10by exploiting backing ledges comprised on the outermost member of kelly10, which are also used for transmitting the excavation torque, e.g. for friction rods, or with mechanical joints implemented through horizontal profiles of the ledges, e.g. for mechanical locking rods. At the top, kelly may be guided by a rod guiding element11, also connected to mast5in a slideable manner, and is preferably provided with guiding or backing members, so as to run in the same way as rotary8or carriage9. Rod guiding member11is normally used for improving the guiding of drill rod or kelly10and for keeping the excavating tool always aligned and accurate, particularly when the guiding provided to kelly10by rotary8is not sufficient to keep the kelly in alignment, especially for inclined, non-vertical drilling.

Drilling machine100further comprises an excavating tool12, represented inFIG. 1as a drill bit, connected to drill rod10, in particular to the innermost member of kelly10, and having a profile capable of transmitting pull and extraction forces and torque.

As clearly shown inFIG. 1, when rotary8is mounted on carriage9there is a distance between the excavation axis, coinciding with the axis of drill rod10and with the axis of rotation of excavating tool12, and the guides of mast5, which distance is referred to as excavation centre-to-centre distance “i”.

Diameter “Ø” of excavating tool12is correlated with excavation centre-to-centre distance “i”. Diameter “Ø” must be equal to or smaller than twice the value of excavation centre-to-centre distance “i”, i.e. it must not exceed twice the value of excavation centre-to-centre distance “i”. In particular, it is preferable that said diameter “Ø” of the tool is smaller than twice the value of excavation centre-to-centre distance “i”, so as to leave the necessary clearance for the excavating tools and for the protruding elements on mast5, such as, for example, the transmission pulleys for the rope of pull-down hoist13, and the ropes themselves, installed on the front side of the mast, in the lower part thereof, particularly the pushing branch. The position of linkage3, shown inFIG. 1in the fully retracted configuration, produces a distance between the excavation axis and the axis of rotation of tower1, referred to as working radius R max. By changing the position of linkage3, in particular by extending it forwards towards the excavation face, mast5will translate and go down, thus further reducing the ground clearance.

FIG. 2shows the same drilling machine100, from which said foot7has been removed from the bottom part of mast5. Since linkage3is of the parallelogram type, linkage3connects to mast5at a very tall height from ground “G”, several metres above ground, and therefore the available space under mast5can be used for inserting excavating tools12having diameters “Ø” much greater than twice excavation centre-to-centre distance “i”.

Not all drilling technologies are compatible with this geometry, in which tool12remains constantly under the bottom end of mast5. In fact, in some cases tubes need to be moved, typically having a variable length of 3 to 6 m, so that they can no longer be housed underneath mast5, and therefore their diameter will have to be correlated with excavation centre-to-centre distance “i” as previously specified. This problem also arises when excavating tools called “buckets” are used, which may be as high as 2 m, and which comprise a bottom bucket that remains partially open during the excavation process, thus promoting the entry of the material inside the tool; once extracted from the borehole, the bucket can be opened in order to discharge the excavated material. With tools having a diameter of 3 m, the minimum height necessary to make room for the open bucket and the cylindrical stem of the tool may exceed 5 m, and therefore also in this case the tool could not be housed underneath mast5.

It is known the patent application EP0548900A2 in which is disclosed a drilling machine of the type comprising a drilling tower fixed in a reclinable manner on a transporting vehicle (11) and provided with motive power units (15) and a driving head (30) for driving the drill rods. The drilling tower is of telescopic type slidable along a fixed guide structure or lattice (24) by the action of a hydraulic piston (23), the telescopic tower being provided at its ends with a series of pulleys (27,35) to allow the movement of flexible transmission means (28,34) having one end connected to said driving head (30) and the other end connected to a point on the fixed structure (24), so as to form a closed ring about the tower. The drilling machine is also provided with a system for stowing and handling the drilling rods.

It is also known the patent application CN202913951U in which is disclosed a power head and a rotary drilling rig with an adjustable pulley yoke center distance. The rotary drilling rig is mainly composed of a crawler belt chassis, an upper revolving vehicle, a main winch, a steel wire rope, a luffing mechanism, a mast, a pulley yoke, a drilling rod, the power head and a drilling bit, the power head is composed of a power head sliding frame, a connection board, a reduction gearbox and an adjusting device, a pin hole arranged on the adjusting device is respectively connected with the power head sliding frame and the connection board, the reduction gearbox is rigidly connected with the connection board, the pulley yoke is composed of a rear pulley yoke body, a rear pulley, an adjusting rod, a front pulley and a front pulley yoke body, one end of the adjusting rod is provided with a hole to be hinged with the rear pulley yoke body, the other end of the adjusting rod is provided with a first hole and a second hole to be connected with the front pulley yoke body, and the rear pulley yoke body, the adjusting rod and the front pulley yoke body are mutually hinged to form a triangle. According to the power head and the rotary drilling rig with the adjustable pulley yoke center distance, drilling diameter ranges of the drilling rig can be enlarged under the condition that the drilling depth is reduced, the drilling depth is increased under the condition that the drilling diameter is reduced, and drilling capacity ranges of the drilling rig are enlarged.

It is the object of the present invention to provide an assembly for driving excavating or drilling equipment for ground which overcomes all the drawbacks of the prior art.

According to the present invention, an assembly for driving excavating or drilling equipment for ground is provided.

Another aspect of the present invention relates to a system for changing the excavation centre-to-centre distance of an excavating machine.

A further aspect of the present invention relates to a machine for excavating ground through the use of drilling equipment.

Yet another aspect of the present invention relates to a method for changing the excavation centre-to-centre distance of an excavating machine.

DETAILED DESCRIPTION OF THE INVENTION

With reference to the above-mentioned figures, the assembly according to the present invention is adapted to drive excavating or drilling equipment (10,12) for ground “G”. Said assembly is particularly suitable for implementation on an excavating or drilling machine100, which may be either a specially designed machine or an existing machine in accordance with the prior art. For simplicity's sake, reference numeral100will be used throughout this description.

For the purposes of the present description, the term drilling equipment refers to one or more drill rods or kellies10and/or one or more excavating tools12connected to said one or more rods.

In general, the assembly according to the present invention comprises a drive assembly (110,900) adapted to slide along a mast5of an excavating or drilling machine100, for driving at least a part of drilling equipment (10,12).

Said assembly also comprises at least one actuator (23,13), which is configured for performing operative functions for driving parts of an excavating or drilling machine100or of drilling equipment (10,12).

Drive assembly (110,900) according to the present invention comprises a first structure or carriage (90,111), in turn comprising guide members (92,116,115) adapted to allow it to slide along said mast5.

Drive assembly (110,900) according to the present invention further comprises a second support structure (80,112) adapted for at least supporting drilling equipment (10,12).

Said first structure or carriage (90,111) and said second support structure (80,112) are mutually movable relative to each other.

Said at least one actuator (23,13) of the assembly according to the present invention is adapted for at least controlling the mutual movement of said first structure or carriage (90,111) and said second support structure (80,112).

Drive assembly (110,900) of the assembly according to the present invention is capable of taking at least two operating configurations. In the different possible operating configurations of the drive assembly, there is a variation in the distance of said second support structure (80,112) from said mast5, particularly at least relative to an axis perpendicular to the axis of extension of said mast5. The variation in the distance of said second support structure (80,112) from said mast5allows the assembly according to the present invention to take at least two different excavation centre-to-centre distances (i1, i2).

In said at least two operating configurations of said drive assembly (110,900), said first structure or carriage (90,111) and said second support structure (80,112) are mutually constrained, in particular in a rigid and direct manner.

In the assembly according to the present invention, between said first structure or carriage (90,111) and said second support structure (80,112) no additional elements, such as extensions, kinematic mechanisms, etc. are needed to allow the drive assembly to take the different operating configurations.

Moreover, in the assembly according to the present invention, while switching between the different operating configurations of drive assembly (110,900), said first structure or carriage (90,111) and said second support structure (80,112) are always directly constrained to each other through at least one mechanical constraint.

In the assembly according to the present invention, said first structure or carriage (90,111) and said second support structure (80,112) are never unconstrained from each other; in fact, there is always at least one mechanical constraint between the structures.

Furthermore, in the assembly according to the present invention said at least one actuator (23,13), in addition to controlling at least the mutual movement of said first structure or carriage (90,111) and said second support structure (80,112), is configured for carrying out further operative functions for driving parts of an excavating or drilling machine100or of the drilling equipment (10,12).

The assembly according to the present invention allows the assembly to switch between the different operating configurations of the drive assembly by exploiting an actuator already present in the machine, which is already employed for other functions. Therefore, the present invention does not require the implementation of a dedicated actuator to allow changing excavation centre-to-centre distance “i”.

In one possible embodiment of the assembly according to the present invention, for switching from a first configuration to a second configuration of the drive assembly (110,900), the mutual movement of said first structure or carriage (90,111) and said second support structure (80,112) is effected by means of at least one rotary movement.

In one possible alternative and exemplary, but non-limiting, embodiment, for switching from a first configuration to a second configuration of the drive assembly (110,900), the mutual movement of said first structure or carriage (90,111) and said second support structure (80,112) is effected by means of at least one linear movement.

In further possible exemplary, but non-limiting, embodiments, the mutual movement of said first structure or carriage (90,111) and said second support structure (80,112) may be a combination of rotary and/or linear and/or rotational-translational movements, according to specific requirements, e.g. a combination of a rotary movement and a linear movement, or a combination of rotary movements.

In general, depending on the implemented type of mutual movement of said first structure or carriage (90,111) and said second support structure (80,112), the type of mechanical constraint between the structure may vary and/or be a combination of mechanical constraints, such as hinge constraints and/or a slider-type constraint, e.g. a prismatic one.

For the purposes of the present description, a slider-type constraint is meant to be a constraint that allows translation in one direction, but no rotation.

By way of exemplary, but non-limiting, embodiment in case of a rotary movement the constraint may be a hinge constraint, whereas in case of a linear movement it may be a slider-type constraint; in case of hybrid movements, e.g. roto-translation, the mechanical constraint may be a combination of hinge and slider-type constraints.

Therefore, in the assembly according to the present invention, while switching between the different operating configurations of drive assembly (110,900), said first structure (90,111) and said second structure (80,112) are constrained via at least one hinge and/or slider-type constraint, preferably prismatic in shape.

In one possible embodiment of the assembly according to the present invention, for switching from a first configuration to a second configuration of drive assembly (110,900), the mutual movement of said first structure (90,111) and said second structure (80,112) is effected by means of at least two rotary movements. In the present embodiment, while switching between two different operating configurations of drive assembly (110,900), said first structure or carriage (90,111) and said second support structure (80,112) are constrained by means of hinge constraints, wherein a first rotary movement occurs relative to a first hinge constraint and a second rotary movement occurs relative to a second hinge constraint.

The present solution allows changing, through two tilting movements, the distance of said second support structure (80,112) from said mast relative to both an axis perpendicular to the axis of extension of said mast5and the very axis of extension of mast5. Preferably, the radii of curvature of the rotary movements are selected in a manner such that the variation relative to the longitudinal axis of the mast is negligible compared to the variation relative to the axis perpendicular to the axis of the same mast5.

It is thus possible to change the excavation centre-to-centre distance in a simple manner, even when said second structure (80,112) has a considerable mass.

In a preferred exemplary, but non-limiting, embodiment, said first structure or carriage (90,111) and said second support structure (80,112) are constrained via removable pin-type fixing means (25a-25D,21,22) adapted to directly constrain said first structure or carriage (90,111) and said second support structure (80,112) in the different operating configurations.

Said pin-type fixing means are adapted to be inserted into suitable holes (93-96,112,113,118-121) made in said first structure (90,111) and said second structure (80,112).

In general, said first structure (90,111) or said second structure (80,112) comprises at least two pairs of holes. In general, the position and number of holes may vary according to the implemented embodiment.

In said embodiment, a first pair of holes (95,96) lie on a first circumference, e.g. having a radius “R1”, and a second pair of holes (93,94) lie on a second circumference, e.g. having a radius “R2”.

Preferably, the centre of said first circumference is one of the holes of said second pair; and the centre of said second circumference is one of the holes of said first pair.

In such an embodiment, said first pair of holes and said second pair of holes lie at different heights relative to the longitudinal axis of said mast5, so that, while making the two above-described rotary movements, the distance of said second support structure (80,112) from said mast (5) will change with respect to the axis perpendicular to the axis of extension of said mast (5), so that at least two different excavation centre-to-centre distances (i1, i2) can be set.

In one possible embodiment of the assembly according to the present invention, for switching from a first configuration to a second configuration of drive assembly (110,900), the mutual movement of said first structure (90,111) and said second structure (80,112) is effected by means of a linear movement. In such an embodiment, while switching between the different operating configurations of drive assembly (110,900), said first structure (90,111) and said second structure (80,112) are constrained by means of at least one slider-type constraint, preferably prismatic in shape.

Said first structure (90,111) or said second structure (80,112) comprises at least one pair of holes. Said pair of holes lie on a straight line parallel to the direction of linear motion of the parts. Said pin-type fixing means are adapted to create a joint-type constraint.

In an advantageous embodiment of the assembly according to the present invention, said first structure or carriage (90,111) and said second support structure (80,112) are constrained to each other by means of pins; each pin is moved axially by a respective actuator201.

The assembly according to the present invention is particularly suitable for being controlled by a control unit, e.g. a PLC installed either in the assembly or in the machine.

Said control unit may be a unit capable of controlling said actuators201and also capable of interfacing to the control unit of excavating or drilling machine100in order to control actuators of machine (13,23).

Said control unit may be able to automate the movements of drive assembly (110,900), thus ensuring a faster and safer change of excavation centre-to-centre distance. In general, implementing pin-type fixing means driven by an actuator allows increasing the safety level and reducing the operators' effort, resulting in shorter machine downtimes. Said control unit can control the driving of the pins and verify the positions thereof.

In general, in the assembly according to the present invention said at least one actuator (23,13), adapted for at least controlling the mutual movement of said first structure or carriage (90,111) and said second support structure (80,112), can exert a force along one direction only, in the desired sense.

In the several possible embodiments of said at least one actuator (23,13), it may be a rope, e.g. rope23, associated with a hoist, e.g. the main or service hoist, or hoist13adapted to drive a carriage90for moving rotary80.

Preferably, the rope and the hoist are already present in drilling machine100and are configured for performing other operative functions for driving parts of an excavating or drilling machine100or of drilling equipment (10,12); in fact, said rope23may be the rope associated with the main hoist for moving the drilling equipment, or the one associated with the service hoist for moving drilling equipment.

Alternatively, the actuators in use may consist of any combination of a rope and a hoist already present in excavating machine100and intended for performing a function on the excavating machine as a primary function and, as a secondary function, controlling the movements between said first structure or carriage (90,111) and said second support structure (80,112) of drive assembly (110,900) of the assembly according to the present invention.

In an alternative embodiment, said at least one actuator is a linear actuator.

Preferably, said linear actuator is at least one hydraulic, electric or pneumatic cylinder. Said linear actuator is an actuator already comprised in drilling machine100, configured for carrying out operative functions for driving parts of an excavating or drilling machine100or of drilling equipment (10,12) as a primary function and, as a secondary function, controlling at least the mutual movements of said first structure or carriage (90,111) and said second support structure (80,112). In one possible embodiment, said linear actuator is adapted to drive carriage90along mast5, as an alternative to the use of hoist13.

In general, said at least one actuator (23,13) is fastened at one end to at least one portion of drilling machine100, and is connected at the other end to at least one of said first structure or carriage (90,111) or said second support structure (80,112) or said excavating equipment (10,12).

As a function of the different possible embodiments of the assembly, and in particular depending on the typology of the first structure or carriage (90,111), e.g. whether or not it is equipped with a drive actuator along mast5, or depending on said second support structure (80,112), in particular its weight and/or its working position on mast5and/or the positioning characteristics on the same mast5, said at least one actuator may be connected to one or more of said first structure or carriage (90,111) or said second support structure (80,112) or said excavating equipment (10,12). Several possible exemplary, but non-limiting, embodiments thereof will now be described, which are applicable in a general sense.

In a first possible embodiment of the assembly according to the present invention, described herein by way of non-limiting example, said drive assembly900comprises a second support structure, which is a drill head or rotary80.

In a second exemplary, but non-limiting, embodiment of the assembly according to the present invention, said drive assembly110comprises a second support structure, which is a central frame112comprised in a rod guide110, to which drill rod or kelly10can be connected.

The different possible embodiments of the assembly, particularly as regards the actuator and the drive assembly, and in particular the connection and movement of the first structure or carriage and said second support structure, shall apply whether said second support structure is rotary80or central frame112.

It must also be underlined that, in the embodiment wherein said second support structure is a drill head or rotary80, the same rotary80can work in all of the operating configurations taken by drive assembly900, in order to carry out an excavation or a drilling operation.

For the purposes of the present description, the term operating configuration refers to that operating configuration taken by the drive assembly in which the working axis of the support structure (80,112) is parallel to the longitudinal axis of mast5. For the purposes of the present description, the term working axis of support structure (80,112) refers to the axis relative to which drilling equipment (10,12) can move when it is associated with the second support structure, i.e. the axis of rotation of the drilling equipment.

In general, the conformation of the assembly according to the present invention allows the second support structure (80,112) to perform the same functions in the different operating configurations of the drive assembly. Therefore, in the embodiment wherein the second support structure is rotary80, the rigid and direct mutual constraint between rotary80and carriage90allows the same rotary to apply the same pull, push and rotation forces, with the same torque, in both of the operating configurations of drive assembly900, when compatible with the stability of the same assembly and/or of excavating machine100whereon the assembly is applied.

The assembly according to the present invention is particularly suitable for being comprised in a system for changing excavation centre-to-centre distance (i) of an excavating machine100.

In general, as previously specified, an excavating machine100adapted to comprise the assembly or the system according to the present invention comprises: a base machine (1,2); a mast5, the upper end of which comprises a head6for supporting the pulleys for the sliding of ropes (23a,23b); and a rotary80, to which an excavating tool12is secured by means of a drill rod or kelly10.

The system or assembly for changing excavation centre-to-centre distance “i” comprises a first carriage (9,90), to which said rotary80is secured, so that it can slide along said mast5; and a second carriage (11,111), in which said drill rod10is suitably housed, so that it can slide along said mast5.

In the system according to the present invention, at least one of a first support structure (8,80), in which said drill rod (10) can be suitably housed, and a second support structure (11,112), in which said drill rod can be suitably housed (10), is comprised in an assembly according to the present invention.

Therefore, at least one support structure has the characteristics of the first support structure (80,112) as previously defined herein.

Advantageously, the first support structure is so constructed as to be comprised in the assembly according to the present invention.

Even more advantageously, an assembly according to the present invention comprises both the first excavating equipment support structure (80) and the second excavating equipment support structure (112).

Therefore, in addition to the carriage adapted for moving the rotary, also other elements of drilling machine100must be adapted and moved in order to change excavation centre-to-centre distance “i”, in particular in order to obtain the full configuration with an extended excavation centre-to-centre distance “i2”.

In a preferred embodiment of the system for changing excavation centre-to-centre distance “i” of an excavating machine100according to the present invention, said head60comprises a drive mechanism (21,63). Said drive mechanism is adapted to drive pulleys62. Said mechanism is also adapted to allow pulleys62to change position, particularly with respect to an axis perpendicular to the axis of extension of said mast5.

The movement of said pulleys62caused by the drive mechanism (21,63) is a movement in accordance with the movement of said assembly, between the different operating configurations of drive assembly (110,900).

The drive mechanism allows adjusting the exit position of main rope23a, which must be located either at an excavation centre-to-centre distance “i1” or at excavation centre-to-centre distance “i2” relative to mast5.

Such variation can be obtained in a simple and known manner, e.g. by installing the front pulley in a more forward position by a distance “d”; therefore, the head has at least one pair of holes at a distance “d” from each other.

In an alternative embodiment, it is possible to install in the same hole a pulley having a bigger diameter. In such an embodiment, the groove diameter of a pulley for working at excavation centre-to-centre distance “i2” will show an increase, compared to the pulley for excavation centre-to-centre distance “i1”, amounting to twice value “d” of the difference between the two excavation centre-to-centre distances (i1, i2).

FIG. 13ashows a head assembly60, wherein on main frame61a pulley62is mounted, on which rope23aof the main hoist is laid and ends up vertically at the excavation axis corresponding to an excavation centre-to-centre distance “i1”.

The pulley is fixed to main frame61by means of a removable pin28.

By removing pin28it is possible to insert an adapter frame63, whereon the same pulley62is mounted, with the same pin28, in a more forward position than the previous one, by a distance “d”, as shown inFIG. 13b. The frame is fixed, by means of a second pin29, to the structure of main frame61, and the structure rotates about pin29. The axis of pin29may not coincide with the hole in which the pin28was originally fixed in the retracted centre-to-centre distance position, shown inFIG. 13a. When rotation is complete, said structure abuts on the frame in proximity to the abutment plane30.

The abutment condition may be locked by means of a removable fastener, e.g. screws, pins, plugs, or frame63may be allowed to swivel about pin29.

By using the main hoist and providing rope23awith an abutment element, it is possible to raise adapter frame63about pin29, so as to overturn it and, in a second variant, leave it installed when switching again to the retracted centre-to-centre distance configuration shown inFIG. 13a.

Rope23aof the main hoist will thus be at a distance from the guides equal to “i2”, corresponding to the extended excavation centre-to-centre distance.

The system according to the present invention allows an excavating machine100to be set to at least two excavation centre-to-centre distances (i1, i2).

The system and/or the assembly according to the present invention are particularly suitable for being comprised in an excavating machine100for excavating ground by means of drilling equipment (10,12).

Excavating machine100according to the present invention comprises: a rotating tower1, in turn comprising: a base frame connected to an undercarriage2; and a mast5, the upper end of which comprises a head6for supporting pulleys6for the sliding of ropes (23a,23b).

The assembly, system and machine according to the present invention allow solving all the problems of the prior art mentioned in the present patent application, as well as many others.

The following will describe more in detail, with reference to the annexed drawings, several possible embodiments of the assembly according to the present invention and of the system and excavating machine100whereto they are applied.

FIG. 3shows, by way of non-limiting example, a first drive assembly900comprised in a first embodiment of the assembly according to the present invention. Said drive assembly900is adapted to allow rotary80to move along said mast5, while allowing changing the excavation centre-to-centre distance at which rotary80can work. The drawing shows a rotary80having the technical characteristics already illustrated above, and a carriage90whereon rotary80is installed. In the present embodiment, in the operating configurations taken by said drive assembly900, carriage90and rotary80are mutually constrained in a rigid and direct manner through a pin-type connection.

For illustrative, but non-limiting, purposes, rotary80comprises a fabricated body or base reducer81and coupling means for toothed wheels and at least one bearing for keeping quill82aligned with the excavation axis. Quill82is the rotary element used for transmitting the excavation forces, in particular the drilling torque. Quill82has an elongated tubular shape, and is fitted with abutment ledges82bengaging with matching ledges of the drill rods or kellies for transmitting the torque and the pull/push forces, e.g. in case of friction-type rods. In the case of drilling by means of mechanically locked kelly rods, the horizontal tracts of the ledges, both the upper and the lower ones, are used as mechanical stops for the extraction pull force and for the push force exerted on rod10. At the bottom, with reference to a vertical axis, quill82may have additional fixing elements for motion transmission, e.g. holes82a, at least one pair thereof, arranged symmetrically relative to the excavation axis defined by rotary80. To such holes82aother devices useful for the excavation activity are connected, e.g. a cardan joint to which the drill pipe is connected, which is adapted to receive the rotary motion and the axial motion of insertion into and extraction from quill drive82. Rotary motion is imparted to quill82by at least one motor or moto-reducer assembly, preferably hydraulically controlled.FIG. 3shows a preferred, but non-limiting, architecture, in which a pair a mechanical reducers83and a pair of variable-displacement motors84are installed. Several different alternative and equivalent configurations are also known in the industry, such as: a single moto-reducer assembly, one or more large-displacement hydraulic motors directly connected without the interposition of a reducer, fixed-speed or shiftable reducers, final reduction stage inside single-stage base reducer81, dual stage reducer, e.g. with a gear change. Alternatively to rotaries80comprising an oil-pressure power unit, rotaries are also known in the industry which can be driven by electric motors, e.g. direct-current, alternating-current, permanent-magnet motors or the like.

In the embodiment shown inFIG. 3, carriage90, according to the present invention, has a main portion91, which is so shaped as to comprise guiding or backing members92adapted to guide carriage90along mast5. In the present embodiment, said guide members92are adapted to slide along prismatic guides provided on mast5. Such guiding or backing members92comprise abutment portions, e.g. ledges made of plastic material or bronze for reducing the coefficients of friction along mast5, or may consist of rolling elements, e.g. rollers with bushings or bearings for further reducing frictions.

In general, said mast5comprises a pair of guides arranged parallel to each other at a predetermined distance.

In a preferred, but non-limiting, embodiment, said guide members are so shaped as to comprise at least three abutment portions for each guide comprised in mast5. In particular, said abutment portions are a front one, a rear one and a lateral one, so as to guide carriage90on three sides along each guide comprised in mast5. Preferably, said guide members are so designed as to comprise abutment portions acting upon each guide of mast5in at least two distinct zones of the same guide spaced apart from each other.

In the embodiment shown inFIGS. 3 and 4, it can be understood that mast5comprises at least two parallel guides, and therefore said guide members92are abutment portions acting upon both guides of mast5. Advantageously, these abutment portions can be short, and therefore, for each guide of mast5, the guide members92are so designed as to comprise abutment portions located at the upper and lower ends of carriage90, with reference to the longitudinal extension of the guide. In the embodiment shown inFIGS. 3-8, it can be understood that the number of abutment portions is twelve.

In general, the shape of guide members92will depend on the shape of the guides comprised in mast5. In fact, in case of cylindrical guides, the corresponding guiding or backing members92comprised in carriage90, according to the present invention, will be provided in the form of bushes or portions of a cylindrical sector, or a pair of rollers oriented at 45° or a plurality of rollers, e.g. three rollers arranged at 90°.

In one possible exemplary, but non-limiting, embodiment, carriage90, and in particular main portion91, supports the hydraulic block85that supplies power to motors84and/or the system that controls the logics of operation. Hydraulic block85receives the tubes coming from rotating tower1, which carry pressurized oil for supplying the power required for the rotation of rotary80.

As an alternative, hydraulic block85may be connected directly to rotary80, being removable by means of screws or pins, and/or having flanged, screwed or quick-coupling, whether single or plate-type ones, tube connections.

In the illustrated embodiment, said fabricated body81of rotary80comprises a plurality of crosspieces, appropriately arranged, in particular in such a way as to form two substantially triangular structures, e.g. forming an “A” shape, adapted to surround rotary80, and in particular the circular structure of fabricated body81, on two sides.

FIGS. 3 and 4show one possible embodiment of drive assembly900in a first operating configuration, wherein excavation centre-to-centre distance “i” is at its minimum value.

Describing more in detail one possible embodiment of drive assembly900according to the present invention, e.g. as shown inFIG. 4, in the upper portion of drive assembly900, with reference to a vertical axis, there is a pin21that connects carriage90to the rotary, wherein rotary80is in a first position, corresponding to the first or retracted operating configuration of drive assembly900. In particular, said pin21is inserted in a first upper hole96comprised in carriage90. In this configuration, excavation centre-to-centre distance “i” of rotary80is at its minimum value “i1”. Under pin21, still with reference toFIG. 4, there is a pin22that connects rotary80to carriage90in the same position corresponding to the first or retracted operating configuration. Specularly, on the other side of carriage90, not visible inFIG. 4, pins21and22are installed in as many holes (96,94) at the top and bottom. In this operating configuration there are four connection points, in particular four holes (94and96), two per side, in which as many pins (21and22) are inserted. Alternatively, the pins may be just two, one at the top and one at the bottom, and be sufficiently long to enter through the holes provided on both sides. It is clear that in the portion of fabricated body81of rotary80there are holes into which pins (21,22) can be inserted in order to rigidly secure rotary80to carriage90in said operating configurations.

In the configuration illustrated inFIGS. 3 and 4, the connection protuberances or brackets comprised in carriage90define the female portion of a fitting, into which the triangular structures of the fabricated body that support rotary8can be fitted. Such triangular structures define the male portion of the fitting. Pin21connects holes96and pin22connects holes94of carriage90, in alignment with the corresponding ones that are present on the structure of rotary80.

Likewise, the parts may be coupled together by reversing the male and female types of the fitting portions between rotary80and carriage90, or by using a mixed configuration, while keeping the characteristics of the present invention unchanged. As a further alternative, rotary80and carriage90comprise each a single section into which the pin can be inserted.

Holes94and96of carriage90are arranged at a distance from each other, with reference to an axis parallel to the longitudinal axis of mast5along which carriage90slides, so as to achieve a maximum possible distance, compatible with the extension in length of carriage90. This feature allows reducing the loads acting upon pins (21,22), so that the latter can be sized favourably in the design phase.

In particular, upper holes96are located in proximity to the top end of carriage90, whereas lower holes94are located in proximity to the bottom end of carriage90.

Continuing the description of the first embodiment shown inFIGS. 3-8, a second pair of holes93and95, e.g. visible inFIGS. 3 and 4, which illustrate the left side of carriage90, are spaced apart from the corresponding holes94and96by the same distance, equal to the necessary increase in excavation centre-to-centre distance “i” in an extended configuration, at least with respect to an axis perpendicular to the axis of extension of said mast5. As already pointed out, holes (93-96) are present on both sides of carriage90.

Advantageously, holes93,94,95,96have the same diameter, so that similar and interchangeable pins (21,22) can be used. In different variants, the holes have different diameters, e.g. the diameter of upper holes95and96is different from that of lower holes93and94. This variant implies that pins (21and22) must be different from each other. In a much less preferred, though possible, manner, the holes have different diameters, thus requiring their own specific pin. This will avoid any mistakes when assembling carriage90and rotary80between the different operating configurations. Reduction bushings may possibly be available, to be inserted into the holes in order to adapt the size of pin (21,22) to that of hole (93-96).

FIG. 4shows a side view of a first embodiment of drive assembly900according to the present invention, wherein a rotary80is connected to the carriage90.FIG. 4shows drive assembly900in a first operating configuration, or retracted configuration, in which excavation centre-to-centre distance “i” is at its minimum value “i1”.

In this operating configuration, pins21and22are connected in holes96and94, which are closer to guiding or backing members92, and therefore to the guides comprised in mast5, so that the excavation centre-to-centre distance “i” is at its minimum value “i1”. When the assembly is applied to an excavating machine100, this first operating configuration ensures the utmost stability of excavating machine100and lower loads on the structures, especially on mast5, the performance being equal.

Hole95lies at a distance “d” from corresponding hole96. By the same distance “d” also hole93is spaced apart, along the axis perpendicular to the longitudinal extension of mast5, from hole94.

FIG. 5shows drive assembly900in a second operating configuration, in which rotary80is mounted on carriage90in a second position corresponding to an extended centre-to-centre distance “i2”. This position is obtained by arranging rotary80, in particular the triangular portion of fabricated body81, and in particular the fixing holes thereof, so that it matches those holes (93,95) on carriage90that are farther from guiding or backing members92, and therefore from the guides comprised in mast5, on both sides of drive assembly900.

In this second position, excavation centre-to-centre distance “i2” will be longer, and in particular equal to:
i2=i1+d.

The increased excavation centre-to-centre distance “i” allows the installation of excavating tools having a bigger diameter Ø, and these can also be placed in the front part of mast5. Of course, this configuration involves higher stress on the structures, including carriage90itself, mast5, linkage3and rotating tower1.

As previously explained, the means for driving rotary80, and therefore carriage90, may be of different types. In the one represented inFIG. 3there is a hole97, located in the upper region of carriage90, into which a pin can be inserted, to which a linear actuator can be fastened. Said linear actuator, e.g. a hydraulic cylinder, or equivalent devices, is adapted to impart the pull and push forces to said carriage90. The actuator in use is per se known. In general, said actuator is connected at one end to carriage90and at the other end to mast5, e.g. in the front part of the same. In an alternative embodiment of the actuator a pulley is used. Said transmission pulley is received in the housing formed on main structure91of carriage90. A rope of the pull branch is run in the upper transmission pulley in the carriage and returns in proximity to the upper part of mast5, preferably secured in head6in order to exert a double-tackle multiple extraction pull on the carriage and the rotary. Motion is imparted to the rope by a hoist13called pull-down hoist. This hoist is preferably arranged on mast5. Likewise, on main structure91of carriage90, specularly to the upper pulley, there may be a second pulley, located at the bottom, in which the rope of the push branch of hoist13is run.

Equivalent embodiments are known which utilize different types of multiple pulls with different numbers of tackles, e.g. the connection of the ropes may be direct, without a transmission pulley, or the push hoist may be connected above or under drive assembly900and the rope may come out from such hoist directed downwards to exert the thrust on the carriage. Alternative implementations of the actuator are also known, such as, for example, the use of other equivalent devices with pinions and a rack, although more expensive and delicate and less powerful in terms of force/speed ratio. Another possible embodiment of said actuator uses a moto-reducer with a closed-loop chain. Such chain is connected at both ends on carriage90, so that the moto-reducer will, by reversing the direction of rotation, either pull or push carriage90.

In general, in the second operating configuration, or extended configuration, the fixing between carriage90and rotary80is effected in the same way as in the first operating configuration, being in particular effected by means of pins and being thus equally rigid and precise.

FIG. 6shows an intermediate condition of drive assembly900, in particular between the first operating configuration, or retracted configuration, in which excavation centre-to-centre distance “i1” is shorter, as shown by way of example inFIG. 4, and the second operating configuration, or extended configuration, in which excavation centre-to-centre distance “i2” is longer, as shown by way of example inFIG. 5.

As previously specified, in the assembly according to the present invention, an actuator already employed for other functions of an excavating machine is used for effecting the mutual movements of said carriage90and said rotary80, e.g. a rope with a hoist or a linear actuator already present on excavating machine100. Such a solution allows working in a simple and safe manner without requiring any auxiliary driving devices.

In one possible embodiment, one of the two hoists already present on excavating machine100may be used, e.g. either the main hoist or the service hoist, without distinction.

Referring back to the conformation of drive assembly900, in one possible and preferred embodiment upper holes95and96of carriage90are situated along the circumference having as a centre one of the other two lower holes (93,94); in particular, in the embodiment shown in the drawings upper holes95and96are located along the circumference having as a centre hole94. The circumference having a radius “R1” has hole94as a centre and passes through the centres of holes96and95. The position of the holes is invariant along the circumference, since the fundamental characteristic is that the distance between the two centres of holes (95,96) is equal to that of lower holes (93,94), i.e. equal to “d”.

In the illustrated embodiment, upper hole96is vertically aligned with hole94, thus moving forward the excavation centre-to-centre by distance “d”; the point where rotary80is fixed to carriage90drops by a negligible value compared to distance “d”, because hole95lies on the circumference having radius “R1”.

In one possible variant, instead of having lower holes94and upper holes96aligned along the vertical, the drive assembly may have upper holes (95,96) in symmetrically opposite positions relative to the vertical joining line passing through the centre of hole94. Since hole96lies on the right side of the vertical, in particular at a distance d/2 from the vertical, and hole95lies on the left side of the vertical, at a distance d/2 from the vertical, a symmetrical condition is obtained in which there is no vertical movement of rotary80when switching between the different operating configurations of drive assembly900, in particular from retracted centre-to-centre distance position “i1” to extended centre-to-centre distance position “i2”.

In a similar and specular manner, all that has been illustrated with regard to holes95and96also applies to holes93and94. In particular, as shown by way of example in the embodiment of the annexed drawings, holes93and94are located along a circumference having as a centre the centre of hole95and a radius R2. Being the distance between the centres of holes95and93equal to that between the centres of holes95and94, in a preferable embodiment it is obtained that R1=R2.

In general, the method for changing an excavation centre-to-centre distance “i” of an excavating machine100according to the present invention, comprising at least one assembly adapted to drive drilling equipment (10,12) according to the present invention, requires the execution of specific steps that allow switching between the different operating configurations while still maintaining a mechanical constraint between said first structure or carriage and said second support structure.

In the light of the different possible embodiments of the assembly according to the present invention, the method can be generalized to encompass all the different possible implementations. In general, the method according to the present invention comprises the following steps:removing at least two pin-type fixing means that constrain a first structure or carriage (90,111) and said second support structure (80,112) of a drive assembly (110,900);mutually moving said first structure or carriage (90,111) and said second support structure (80,112), so as to switch from a first configuration to a second configuration, controlling the movement by means of at least one actuator (23,13);constraining again said first structure or carriage (90,111) and said second support structure (80,112) by means of said at least two pin-type fixing means.

In the embodiment wherein the mutual movement of said first structure or carriage (90,111) and said second support structure (80,112) is of the rotary type; and in particular in the embodiment wherein said first structure or carriage (90,111) and said second support structure (80,112) are mutually constrained in the different configurations through first pin-type fixing means (21), adapted to define a first constraining axis, and second pin-type fixing means (22), adapted to define a second constraining axis, specific consecutive steps are required. In particular, for switching from a first operating configuration to a second operating configuration of drive assembly (110,900), the following successive steps are carried out:removing the first pin-type fixing means (21), thereby releasing a first constraint;mutually moving said first structure or carriage (90,111) and said second support structure (80,112), so as to switch from a first operating configuration to an intermediate configuration, turning about said second constraining axis;constraining again said first structure or carriage (90,111) and said second support structure (80,112) by means of said first pin-type fixing means;removing said second pin-type fixing means, thereby releasing a second constraint;mutually moving said first structure or carriage (90,111) and said second support structure (80,112), so as to switch from said intermediate configuration to a second configuration, turning about said first constraining axis;constraining again said first structure or carriage (90,111) and said second support structure (80,112) by means of said second pin-type fixing means.

In this implementation of the method, in order to switch from a first operating configuration, e.g. the retracted configuration, to a second operating configuration, e.g. the extended configuration, two rotary or tilting movements are necessary by turning about constraining axes. Such a solution is particularly suitable for application in embodiments wherein the second support structure (80,112) has a considerable mass, at least greater than the mass of the first structure or carriage (90,111), e.g. in the embodiment wherein said second support structure is a drill head or rotary80. Anyway, this sequence of steps can be implemented also for other embodiments of the assembly, in particular of the drive assembly.

The method according to the present invention can be automated. For example, it may be implemented, at least partially, by means of a control unit. Said control unit is adapted to appropriately activate one or more actuators and/or to receive data from sensors for the purpose of executing and/or controlling, at least partially, one or more steps of the method according to the present invention. In one possible exemplary, but non-limiting, embodiment, said control unit is the control unit of excavating machine100. Said control unit is adapted to allow and/or control the execution of one or more steps of the method.

As an alternative, said control unit is a control unit remote from the assembly, system and/or excavating machine100according to the present invention.

With reference to the specific embodiment shown by way of non-limiting example inFIGS. 3-8, in order to allow the mutual movement of rotary80and carriage90it is necessary to carry out a number of steps, such as, for example, connecting one end of a rope23of one of the two hoists to rotary80at a connection point. Said connection point preferably does not lie in any one of the planes that join holes94and96or95and93on both sides of drive assembly900. Preferably, the connection point is located at that end of the rotary which is farther from carriage90. In a first configuration, rotary raising point86is only one and is positioned in the upper part of rotary80itself, so that it can be directly reached by the ropes descending from head6of mast5. As already described, it is possible to use other holes or multiple hooks and connection points at the same time.

In order to allow the switching between the different operating configurations, and in particular from the first operating configuration, or retracted configuration, to the second operating configuration, or extended configuration, e.g. via an intermediate configuration, it is necessary to remove pin21in order to release a first constraint.

In light of the possible arrangements of holes (93-96), and since the centre of gravity of drive assembly900is eccentric relative to the fixing points that connect carriage90to rotary80, rotary80will tend to rotate under its own weight, thereby promoting the movement, when the mast is in the vertical condition. Therefore, in order to cause rotary80to turn about pin22fixed in hole94, it is sufficient to remove pin21from hole96and release rope23. During the rotation, hole95is clear. When the centres of the holes comprised in carriage90and rotary80are aligned, pin21can be inserted again into hole95. This is because holes95and96advantageously have the same diameter.

Once pin21has been re-inserted, an intermediate configuration is reached wherein carriage90is again rigidly and directly connected to rotary80.

During this movement, the only function performed by the actuator of the assembly according to the present invention, was to control the mutual movement of said carriage90and said rotary80. In fact, in the present embodiment the force that allows the mutual movement of carriage90and rotary80is the weight force acting upon rotary80.

In order to find the correct position, it is also possible to use video cameras, or locator means, whether removable ones to be temporarily installed during the movement stages or permanent ones, preferably adjustable, fixed to the structure. The locator on hole96is adjusted with pin21inserted in hole96. The locator on hole95is adjusted with pin21on the hole95. Once the outermost positions have been adjusted, it is possible to carry out the rotations of rotary80on carriage90by simply coming in abutment. The locators may be common devices with screw-type adjustment, or locking-hat, key-type or hydraulic devices, or ties, e.g. ropes and chains, the length of which is adjusted to allow the required arc of rotational movement.

Advantageously, pins21and22have a tapered point that facilitates the insertion of the pin and does not require a precise alignment of the holes.

When one wants to switch from the intermediate configuration to the first configuration, i.e. to make a reverse movement compared to the one described above, e.g. to turn rotary80clockwise in order to insert pin21into hole96again, it is possible to pull rope23by winding it on the hoist, activating said at least one actuator of the assembly according to the present invention. During this movement, the actuator of the assembly according to the present invention is adapted to carry out, and not only control, the mutual movement of said carriage90and said rotary80.

In a second drive variant, the hoist that exerts tension on rope23is not moved, but a longitudinal movement is exerted on carriage90by the means that drive the carriage itself along mast5, e.g. hoist13or the pull-down cylinder or other equivalent means fixed to carriage90for exerting forces on the carriage in the longitudinal direction of mast5and for exerting pull and/or push forces on rotary80.

In such an embodiment of the assembly according to the present invention there are two actuators which, in addition to controlling the mutual movement of said first structure or carriage (90,111) and said second support structure (80,112), are both configured for carrying out further operative functions for driving parts of an excavating or drilling machine100, as previously specified. In this case, an actuator, and in particular rope23connected to a hoist, is adapted to control the movement of drive assembly90between the various configurations, while the other actuator, normally adapted to drive carriage90along mast5, is adapted to exert a force that allows the mutual movement of carriage90and rotary80. In fact, by lowering carriage90along mast5, since rope23is connected to connection point86and locked, rotary80is made to turn about pin22, which is fixed to hole94, by dropping carriage90whereon hole94is present.

FIG. 7shows the intermediate configuration of the drive assembly, between the first configuration, or retracted configuration, and the second configuration, or extended configuration. This intermediate configuration is the starting position of the next step, wherein the movement of rotary80from the position with a retracted centre-to-centre distance to the position with an extended centre-to-centre distance, and vice versa, is completed.

In order to continue the switching between the different operating configurations, and in particular from the first operating configuration, or retracted configuration, to the second operating configuration, or extended configuration, e.g. in order to switch from the intermediate configuration to the second operating configuration, it is necessary to remove pin22in order to release a second constraint. By removing pin22from hole94, a second constraint will be released and it will be possible to mutually move said carriage90and said rotary80.

For example, by exerting a pull force on rope23it is possible to raise rotary80. Rotary80will turn about pin21fixed in hole95, and consequently the hole on rotary80will move from the position aligned with hole94to the one aligned with hole93.

As an alternative to exerting a pull force on rope23, it is possible to not activate the hoist that exerts tension on rope23and exert a longitudinal movement on carriage90through the means for driving the carriage along mast5, e.g. through hoist13or the pull-down cylinder or other equivalent means fixed to carriage90to exert forces on the carriage in the longitudinal direction of mast5and to exert pull and/or push forces on rotary80, as previously described.

Once the holes comprised in carriage90and rotary80have been aligned, it is possible to insert pin22into hole93.

In this case as well, it is possible to insert locator elements and any other variants already illustrated, e.g. pushing carriage90or dropping it by activating the means for driving carriage90itself and leaving the hoist to which rope23is connected in a fixed position.

FIG. 8shows a perspective view of drive assembly900in a second operating configuration, or extended operating configuration, wherein there is an extended working centre-to-centre distance “i2”. In this operating configuration of drive assembly900, pins21and22are respectively fixed into holes95and93, spaced apart along the axis perpendicular to the axis of mast5by a quantity “d” from the previous ones, so as to increase the excavation centre-to-centre distance to the value i2=i1+d.

After working centre-to-centre distance “i” has been extended, drilling machine100, comprising an assembly according to the present invention, will be able to work with tools having a much bigger diameter “Ø”, e.g. diameters increased by a value equal to twice the value of “d” compared to the diameters that can be used in the operating configuration with a retracted working centre-to-centre distance “i1”.

The embodiment described herein allows switching from the first configuration to the second configuration of drive assembly900, and vice versa, and the mutual movement of carriage90and rotary80occurs by means of at least two tilting movements.

As an alternative, it is possible to implement a drive assembly900wherein the mutual movement of carriage90and rotary80occurs by means of at least one linear movement, and wherein, while switching between the different operating configurations of drive assembly900, said carriage90and rotary80are constrained by at least one slider-type constraint, preferably prismatic in shape.

In a second embodiment of the assembly according to the present invention, as previously specified, said drive assembly110comprises a second support structure, which is a central frame112comprises in a rod-guide110, to which drill rod or kelly10can be connected.

In general, rod-guide11may be present on an excavating machine100, in which case it must also be able to change working centre-to-centre distance “i”.

In the second embodiment of drive assembly110, it comprises a first structure or carriage provided as a first frame111slideably connected to guiding mast5through guiding or backing members comprised in said first frame11. Such guide members are, for example, sliders116. Said first frame111has a series of holes that are used for positioning central frame112, which constitutes the second support structure of drive assembly110. To such central frame112drill rod or kelly10is connected through flange117, e.g. through the interposition of a centre plate in order to allow rod or kelly10to turn when rod guide110is not rotating.

Advantageously, sliders116are mounted on a hinged structure115that can be opened by rotation, thus allowing full access for maintenance and replacement of the sliders, e.g. three on each side, i.e. left and right, of the guide, as shown by way of example inFIGS. 9, 10, 11.

Alternatively, the guide members may consist of bronze or plastic sliders to reduce the coefficient of friction, or may be provided as rolling bearings.

In the illustrated embodiment, the first frame111is connected to central frame112by means of four pins25a,25b,25c,25d. Alternative embodiments may comprise a different number of pins, e.g. three or two or more than four.

In the illustrated embodiment, the first pair of pins25aand25bis aligned with at least one other hole113on the first frame111. The same applies to pins25c,25dand hole114.

In the case illustrated inFIGS. 9, 10, 11, central body112represents the female part of a slider-type constraint, e.g. prismatic in shape. Therefore, the first frame111represents the male part of the mechanical constraint, but the constraint parts may also be reversed, and additional holes113,114may be located on central frame112.

In an alternative embodiment, while switching from the first configuration to the second configuration of drive assembly110, and vice versa, the mutual movement of the first frame111and central body112occurs by means of at least two rotary or tilting movements, e.g. in a way similar to the one previously described with regard to the movements of carriage90and rotary80.

FIG. 10shows rod guide assembly10installed in a first operating configuration, or retracted configuration, with a retracted excavation centre-to-centre distance “i1”.

In the exemplary, but non-limiting, embodiment ofFIG. 10there are four pins, wherein pins25a,25b,25c,25dadvantageously have the same diameter and the same length. This embodiment allows said pins to be interchanged. Preferably, at least pins25aand25bhave the same diameter, and the same applies to pins25cand25d.

The exemplary, but non-limiting, embodiment ofFIG. 11shows drive assembly or rod guide110in a second operating configuration, or extended configuration, with an extended excavation centre-to-centre distance “i2”.

One possible method for changing an excavation centre-to-centre distance “i” of an excavating machine100according to the present invention, wherein the drive assembly is a rod-guide110, comprises the following steps:removing at least two pin-type fixing means that constrain a first structure or carriage (90,111) and said second support structure (80,112) of a drive assembly (110,900);mutually moving said first structure or carriage (90,111) and said second support structure (80,112) by means of a linear movement, so as to switch from a first configuration to a second configuration, controlling the movement by means of at least one actuator (23,13);constraining again said first structure or carriage (90,111) and said second support structure (80,112) by means of said at least two pin-type fixing means.

Describing the construction of one possible embodiment more in detail, the mutual movement of frames (111,112) can occur after the removal of the fixing pins, i.e. pins25a,25b,25c,25d. In the illustrated embodiment, the switching between the different operating configurations is effected by causing the first frame111and second central frame112to slide relative to each other.

During the relative sliding occurring between the frames of rod-guide110, a prismatic mechanical constraint is in effect, as can be clearly understood from the drawings.

By moving the two frames (111,112) away from each other, it is possible, after aligning holes113and114of both frames (111,112), to insert pins25band25d. Pins25aand25cthat were fixed into holes118and119can be used for fixing frames (111,112) to each other in the middle holes previously occupied by pins25band25d, as shown by way of example inFIG. 10.

In the present embodiment, the three holes per side of rod-guide110are distant from each other by the same quantity “d”. The extension sliding action results in a desired increase of the excavation centre-to-centre distance “i”, which becomes i2=i1+d.

In an equivalent solution there may be just four holes, two on each side of rod-guide110, e.g. holes113,121and holes114,120, spaced apart by a quantity “d”. As an alternative, it is possible to generate intermediate configurations between the first operating configuration and the second operating configuration of rod-guide110, wherein multiple fixing holes may be provided to move the two frames (111,112) relative to each other by desired quantity “d”.

The pins may be either fully removable or integral with either frame, advantageously with the female one, in this case central frame112.

When integral with a frame, they can be raised in a position that allows clearing the holes of the other frame, thus longitudinally disengaging the two frames from each other, so that relative movement can be effected, in particular by sliding them relative to each other. When the new position is reached, the pins can be lowered again and inserted into the holes of the other frame. In one possible embodiment, rod guide110implements snap-action pins.

In general, if the pins are equal, at least in pairs, it is possible to use the pins of each pair without distinction in order to fasten the two frames (111,112).

FIG. 12shows the second embodiment of the assembly for driving excavation or drilling equipment (10,12) according to the present invention.

This embodiment is exemplary only and non-limiting, but represents an advantageous approach for reducing the downtime necessary for changing working centre-to-centre distance “i”.

During the manoeuvres for dismounting drill rod or kelly10, necessary for disengaging rotary80, e.g. for ensuring that excavation centre-to-centre distance “i” can be changed as previously described and illustrated, it is possible to exploit the hoist normally used for raising rod or kelly10in order to adjust working centre-to-centre distance “i” on rod-guide110.

Drill rod or kelly10is placed in a configuration lowered to ground “G”, wherein its bottom end lies on the ground, e.g. at point “P”, and the other end is connected to rope23of one of the hoists available for this raising operation. Advantageously, it is possible to use rope23aof the main hoist, because the latter is installed in alignment with the axis of rotation of excavating tool12. Said rope23is connected, in particular, to the top end of drill rod10, e.g. of the innermost element of a telescopic kelly, preferably through the interposition of a swivelling joint.

When rope23is slackened, the drill rod or kelly10will tend to go down under its own weight, turning about point “P”.

Preferably, when a height reachable from the ground is arrived at, pins24a,24b,24c,24dare removed in order to disengage the two frames (111,112) of rod-guide110from each other.

In particular, this disengagement can occur when also the bottom end of rod guide110, in particular the first frame111, lies on ground “G” or against a backing element placed on the ground.

Assuming to start from the first operating configuration, or retracted configuration, with an excavation centre-to-centre distance “i1”, by raising drill rod or kelly10it is possible to cause the first frame111and central frame112to slide relative to each other under their own weight, until the second operating configuration, or extended configuration, is reached. Once this latter operating configuration has been reached, it is possible to insert the pins into the holes corresponding to the new position that provides extended excavation centre-to-centre distance “i2”.

Vice versa, in order to reduce the excavation centre-to-centre distance, e.g. in order to switch from the second operating configuration to the first operating configuration of rod guide110, after having laid drill rod or kelly10on the ground at point “P”, and having also laid on the ground rod guide110at the opposite end, the pins can be disengaged and rope23can be released, e.g. by unwinding the hoist, preferably the main hoist, in order to cause the first frame and the central frame of the rod-guide to slide relative to each other. Said main hoist, as previously specified, may be located either on rotating tower1or on mast5. By releasing the rope, it is possible to re-close the two frames (111,112) of rod-guide110until the retracted operating configuration is reached, in which the fixing pins will be inserted again into the respective holes.

In order to facilitate the steps of switching between the different operating configurations, it is possible to employ mechanical locators, as described with reference to the preceding embodiment of the assembly. Said mechanical locators may be adjustable, if necessary, e.g. via a screw mechanism, and are preferably removable. Such an embodiment allows sliding the two frames (111,112) relative to each other by a desired or required quantity, e.g. a quantity “d”. In this case as well, the pins may advantageously have a tapered point to facilitate the assembling.

The devices described so far in the different embodiments of the machine, system, assembly and drive assembly have removable pin-type fixing systems that are moved, removed, even only partially, and reversed manually.

FIG. 14shows a variant wherein the pin is motorized and controlled automatically, e.g. remotely.

Pin204may be any one of those previously described, i.e. any one of pins21,22,25a,25b,25c,25d,28. The motorized pin can be implemented for all of the above-described pins.

For illustrative purposes, in order to allow understanding the characteristics of the pin, frame205that in this case is shown as having a double bracket, i.e. a female bracket, may be a structure of drive assembly (110,900), e.g. the first structure or carriage (90,111). The second frame, not shown in the drawing, is inserted between the two walls205aand205bof frame205. The second frame may be the other structure of drive assembly (110,900), e.g. the second support structure (80,112). The second frame, not shown, is secured by pin204, which is inserted into its hole and, after running past the second frame, is centred and inserted into hole206on part205bof the first frame205, thus constraining the two frames together.

Pin204comprises an actuator that allows the pin to make an axial movement. Said actuator can receive a drive signal preferably sent, e.g. remotely, from the cabin of rotating tower1, or from a remote control, whether an electric or wireless one. In a preferential embodiment, the actuator is a linear actuator201, e.g. a hydraulic cylinder. In a second variant, said linear actuator201may be powered by equivalent and alternative types of energy, such as, for example: electric, pneumatic, magnetic. Linear actuator201is removably fixed to spacer202through a fitting203, preferably by means of screws, to allow dismounting pin204from the seat.

The pin is driven by actuator201, which moves it axially from an extended or engaged configuration to a retracted or disengaged configuration. In the extended configuration, as shown inFIG. 14, the head of the pin engages into hole206on wall205b, opposite to wall205awhereon spacer202is integrally or removably fixed. In the retracted or disengaged configuration, the pin moves back into spacer202, which acts as a protector. In one embodiment, in the retracted or disengaged configuration pin204remains engaged in hole208of the first wall205a, so as to fully clear the hole of the second frame and allow the latter to move relative to frame205. Pin204has a tapered head portion to facilitate the insertion and centring of the holes through which it must run.

A position sensing device207, e.g. a limit switch, may detect the inserted position of the pin and send a signal to the control unit of the machine, indicating that the pin has been inserted.

The drawing shows a female frame205, but it is clear that the frame may have just one wall and connect to the second frame, which also has just one wall. In such a case, the actuation system may be mounted on either wall without distinction, on the side opposite to that where the same walls of the frame are coupled together.

It is apparent that in the drive systems or drive assemblies described above, fromFIG. 3toFIG. 13, each pair of frames unconstrained or constrained by means of pins may comprise a motorized pin, e.g. as previously described and illustrated inFIG. 14.

Preferably, actuator201is positioned outside the structure of the drive assembly, e.g. outside the first structure or carriage, so as to avoid taking up space internally.

With reference to the embodiment of drive assembly900having a carriage90and a rotary80, wherein the relative movements of the parts are rotary movements, it is preferable that one actuator be associated with the pin in each hole. With reference to the illustrated embodiment, four actuators and four pins will be required on the left-hand side and as many actuators and pins will be required on the opposite, right-hand side of drive assembly900.

With reference to the embodiment of drive assembly110illustrated inFIG. 10, the actuator may be fixed to central frame112at pins25a,25b,25c,25d. When only two pins are used, only two actuators will be necessary, which may work either synchronously or autonomously and independently.

The advantages of the assembly for driving parts according to the present invention are apparent in light of the above description and the annexed drawings.

More in detail, the following can be inferred:the connections between the structures of the drive assembly are rigid ones, e.g. using pins, with no adjustment linkages that would introduce play in the couplings and promote the arising of vibrations in operating conditions, resulting in excavation inaccuracy;no dedicated actuators are necessary for moving the parts or structures of the drive assembly in order to switch between the different operating configurations, because an actuator already present on the machine is used which is configured for carrying out additional operative functions for driving parts of an excavating or drilling machine100or of the drilling equipment, e.g. one of the hoists not used in the steps of changing the excavation centre-to-centre distance, resulting in considerable savings in economical and practical terms;it is not necessary to install complex and heavy driving devices in areas on the excavation face, which cause great instability of the machine;the switching from one operating configuration to the other is carried out in a short time, e.g. a few minutes, resulting in a considerable advantage in terms of time and productivity, thus considerably reducing the machine downtimes;it is not necessary to install any heavy and expensive spacers or third elements that require the complete disassembling of the parts to be spaced apart, resulting in wasted time;it is not necessary to use any external handling systems, e.g. cranes, to support the parts during the movements;it is not necessary to disconnect the ropes or the hydraulic (or electric) power supplies in order to dismount motorized parts, such as the rotary, thus reducing the transformation times and preserving the environment against contamination from hydraulic fluids;the system as claimed inFIG. 3allows switching, through a few simple movements, from a retracted configuration to an extended configuration by means of plain rotations that are safe, simple and easily controllable, while also being automatable;the ease of switching from a retracted configuration to an extended configuration allows the machine to be quickly set up for switching from reduced-diameter tools to increased-diameter tool, so that the same machine can be configured for two different technologies, or anyway for an extended range of use;it is not necessary to fully replace parts of the machine, such as carriages or a rod-guide with a short centre-to-centre distance, with other parts suitable for working with an extended centre-to-centre distance, thus reducing the costs and being able to work continuously with the same parts, by simply changing the conformation of the drive assembly via a relative movement of the parts thereof;the possibility of automating the system and controlling it remotely allows, in countries where it is not advisable to work at height for safety reasons, changing the excavation geometry without requiring the personnel to intervene directly, leading to improved safety.

The following will describe a sequence of steps for changing the excavation centre-to-centre distance “i” of an excavating or drilling machine100. This sequence of steps is merely exemplary and non-limiting, and explicitly refers to the specific embodiments illustrated in the drawings.

Preferably, drilling machine100is configured in a vertical position, as shown by way of example inFIG. 1, and is set up with the following devices: rotary80, carriage90, head60, rod-guide110, if present, with a telescopic drill rod or kelly10, installed at retracted excavation centre-to-centre distance “i1”.

In order to switch from the first operating configuration at working centre-to-centre distance “i1” to the second operating configuration at working centre-to-centre distance “i2”, the following procedure is carried out:step1: dismounting drill rod or kelly10by extracting it from mast5in accordance with the normal procedures, raising the drill rod past rotary80, while rotary80is positioned at the bottom part or base of mast5. Drill rod10is lowered to the ground until its bottom end, opposite to the point where rope23ais hooked, touches ground “G” at point “P”;step1a: if rod-guide110is present, it is possible to remove drill rod or kelly10from the mast only after having disengaged rod-guide110from the guides of mast5, e.g. by raising rod or kelly10, using the main hoist, by means of rope23aup to the point on mast5where the guides have recesses that allow rod-guide110to be disengaged from the guides of mast5;step1b: as an alternative to step1a, opening guides115, turning them about the hinge and disengaging them from the guides on mast5; rod-guide110is located near the top of mast5, whereas rotary80is in proximity to the base of mast5, so that also the longest rods or kellies10can come out of rotary80from above the same rotary80;step2: with rotary80still positioned near the base of mast5, preferably in a position that can be reached from the ground, connecting rope23of one of the available hoists to rotary80. For example, the available hoist may be the service hoist, because the main hoist may still be connected to rod or kelly10. The rope of the hoist is fastened to rotary80at any hooking point, preferably at hook86. It is then possible to remove a first constraint, e.g. pin21on the left-hand side and pin21on the right-hand side, getting ready for the rotation of rotary80relative to carriage90about the axis passing through hole94in which pin22is inserted;step3a: while modulating the pull force of the hoist, a suitable tension is exerted on rope23which allows releasing the rotary and causing it to rotate under its own weight, until the hole on the frame of rotary80becomes coaxial to the one95of the carriage, into which pin22is then inserted on both the left-hand and right-hand sides, thus taking an intermediate configuration;step3b: as an alternative to the preceding step, pull modulation is effected by acting upon the pull/push system connected to carriage90while rotary80is being held by rope23only, which is not actuated during this step; by raising carriage90, i.e. sliding it towards the top of the mast, rotary80is made to rotate until the upper hole of its frame81reaches hole95; when such holes are coaxial, pin21is fixed into left-hand hole95, and the same is done on the right-hand side;step4: lower pin22is extracted from hole94, thus allowing rotation about the axis of hole95, on both the left-hand side and the right-hand side;step5a: while modulating the pull force of the hoist, a suitable tension is exerted on rope23which allows pulling the rotary and causing it to rotate, driven by the hoist, which overcomes the weight of rotary80, until the hole on the frame of rotary80becomes coaxial to the one93of carriage90, into which pin22is then inserted on both the left-hand and right-hand sides;step5b: as an alternative to the preceding step, pull modulation is effected by acting upon the pull/push system connected to carriage90while rotary80is being held by rope23only; by lowering carriage90, i.e. sliding it towards the base of the mast, rotary80is made to rotate until the lower hole of its frame reaches hole93; when such holes are coaxial, pin22is fixed into left-hand hole93, and the same is done on the right-hand side. At the end of this step, drive assembly900will be already in the second operating configuration, since it can already operate at working centre-to-centre distance “i1”;step6: at the end of step5, or after step1when rod-guide110is present, with the bottom end of rod or kelly10resting on the ground at point “P”, the descent of rope23ais modulated by releasing the main hoist, until rod-guide110lies on the ground or against a backing element; pins (25a,25b,25c,25d) that secure the two frames111and112are removed and, while raising rod or kelly10by pulling rope23a, central frame112is raised relative to the first frame111, which stays low under its own weight; when the new operating configuration, or extended configuration, is reached, the pins are fixed into the new holes113;114and into the previous holes121and120;step7: rod or kelly is disconnected from the main hoist, e.g. by disconnecting rope23a, preferably from the internal element of the telescopic rod:step8a: mast5is lowered into the transport condition in order to adapt head60to the new excavation centre-to-centre distance “i2”, and then mast5is brought back into the vertical configuration;step8b, to be carried out as an alternative to step8a: the work on head60is carried out at height, and changes are made thereto in order to obtain the new excavation centre-to-centre distance “i2”;step9: drill rod or kelly10is installed after connecting rope23aof the main hoist to rod10, in particular to the innermost element of the rod, proceeding in reverse order to the order laid down in steps1,1aor1b.

In the light of the present sequence of steps, as well as of the previous description and the annexed drawings, a person skilled in the art will be able to determine a sequence of steps necessary for switching from the second operating configuration with an extended centre-to-centre distance “i2” to the first operating configuration with a centre-to-centre distance “i1”.

Drilling machine100is generally equipped with at least one control unit, through which information is gathered from the sensors installed on the machine in order to detect positions, speeds, pressures and any other parameters useful for the execution of the excavation work, whether during the drilling operations or during the handling and translation operations. The control unit processes the information and outputs data, and also sends alarms for the operator on control panels, e.g. in the cabin or on a remote console, and, if necessary, directly controls the actuators and motors in order to set the machine into a safe condition.

Likewise, such functionality can also be applied to the assembly and the system for changing the centre-to-centre distance, as well as to the method for changing the centre-to-centre distance, as described above.

In particular, with reference toFIG. 3, the minimum level of control that can be provided concerns the mutual movement of the first structure or carriage (90,111) and the second support structure (80,112), e.g. the relative movement between rotary80and carriage90, e.g. for the purpose of carrying out the two rotations necessary for switching from hole96to hole95, and/or from hole94to hole93, and vice versa. Since the arc of rotation is known, and so are distances “d”, also the angle of rotation is known. In one possible embodiment, for example, the rotation corresponds to an angle of 11° for both the upper holes and the lower holes.

In order to determine the angle of rotation between rotary80and carriage90, the control unit can, e.g. by means of an inclinometer integral with the frame of rotary80, determine the differential inclination relative to carriage90. The control unit can also determine an actual value between the two structures, in that carriage90is aligned with mast5, which already has an inclinometer necessary for ensuring the verticality of mast5and hence of the excavating tools. The differential angle between the two readings of the two inclinometers will determine the actual rotation between parts (80,90), which will have to be equal to the angle of rotation, i.e. for example, 11°.

Since it is possible to determine the actual angle of rotation, the control unit can send a signal for the operator for stopping the movement in the positions that allow the insertion of the pins, or, in a more automated version, it may issue closing commands towards automatic latches or actuators201. In this case, no manual intervention will be required.

As an alternative, in the case wherein the mutual movement of the parts is achieved by operating one of the actuators already present in the excavating machine, e.g. the hoists, and in particular the main hoist or the service hoist, it is possible to determine the relative movement, for example, by means of a depth meter measuring the extent of unwinding of the rope. Encoder-based systems are known which measure depth starting from the number of revolutions, e.g. of the motor or the reducer or the drum of the hoist, or magnetic sensors measuring, for example, the revolutions of the drum in order to determine the extent of unwinding of the rope, or devices directly measuring the moving end, e.g. rope-based, optical or laser devices.

Depending on the point where the rope is attached to drive assembly900, and depending on the known geometry of rotary80and carriage90, through the control unit it is possible to determine the rotation required for switching between the two holes by sliding rope23in length. The control unit may possibly display the reading on a control display and/or activate alarm signals and/or activate the direct control over actuators201in order to fix the pins into the new positions when the rotation is complete.

In a similar manner, the control unit can control the relative movements of carriage90and rotary80when the carriage is driven by means of pull-down hoist13or the pull-down cylinder. If the actuator of the assembly according to the present invention is pull-down hoist13, and knowing the position of rotary80along mast5, it is possible to determine the incremental value of the movement, which depends on the same variables previously indicated for the preceding embodiment, wherein a hoist moved rope23. Also in this latter embodiment, the movement may be effected under control of the control unit, with the resulting actions as already described.

Wholly similar concepts still apply when using, instead of a hoist, the linear actuator adapted for driving carriage90, controlling it by means of the control unit.

Sensors may be electronically connected to said control unit, e.g. proximity or position sensors, which may use different technology, e.g. electronic, magnetic or lever-type sensors, in order to sense the positions, e.g. the end-of-travel positions between the start point and the end point, e.g. between holes95and96. Once they have been properly adjusted, it is possible to know the exact position of rotary80when it is in either position. These signals are collected by the control unit in order to send signals and/or actuation commands as previously described.

A sensor, e.g. a limit switch207like the one shown by way of example inFIG. 14, may be installed to determine if the pin has been fully inserted, as a confirmation of the locking of the two parts, with the option of issuing an enable signal or unlocking an operating condition that was previously locked or forbidden.

The assembly, system, machine and method described so far, as well as all the various optional embodiments described and illustrated herein, may be subject to variations, additions and modifications that, in the light of the present description and of the annexed drawings, can be easily inferred by a person skilled in the art without however departing from the protection scope of the appended claims.

By way of example, as shown inFIGS. 3 to 8, the whole drive system has been described herein with reference to the sequence for switching from a retracted first excavation centre-to-centre distance “i1” to an extended second excavation centre-to-centre distance “i2”, in particular by rotating first the upper holes from96to95and then the lower ones from94to93, so that, as a consequence, the upper holes lie on an arc of circumference having as a centre the hole in which, at excavation centre-to-centre distance “i1”, pin22is inserted at the bottom, i.e. the hole that is closer to guide members92of carriage90, specifically hole94; while the other two lower holes94and93have as a centre upper hole95, which is farther from guide members92of the same carriage90.

It is obvious that it is possible to rotate drive assembly900while leaving pin21inserted in hole96. In this case, lower holes93and94will be positioned on a circumference having as a centre hole96in which pin21is fixed. Subsequently, holes95and96will be arranged on a circumference that will have as a centre hole93in which pin22is fixed in the intermediate configuration, equivalent to the one illustrated inFIG. 6.

For the purposes of the present invention, the term pin, e.g. pins21and22, refers to either a pin passing through the first structure or carriage, e.g. carriage90, from one side to the other thereof, which uses at least one hole available on the second support structure, e.g. the frame of rotary80, and at least one hole available on the same first structure or carriage, or, preferably, at least one hole on the second support structure and at least two holes on the first structure or carriage, or, as a further alternative, two or more holes on the first structure or carriage and two or more holes on the second support structure. In a preferable embodiment, pin21on the left side that secures the first structure or carriage to the second support structure is complemented with an opposite hole on the right side, coaxial to the former, which secures the first structure or carriage to the second support structure also on the opposite side. The same also applies to pin22. In a preferred embodiment, the structures of rotary80, and in particular of fabricated base81, and of carriage90, and in particular of frame91, are symmetrical with respect to a vertical and longitudinal plane passing through the centre of rotation of quill82and through the centre line of motors84, and therefore the holes shown on the left side are also present on the right side (see hole95′ symmetrical to the hole95inFIG. 3).

In general, in a preferred but non-limiting embodiment, each pair of holes (95-96and93-94) is present on the female frame, whereas the male frame may have only one hole for fixing it to the holes of one pair. In the more specific case of drive assembly900, if rotary80has a female frame and carriage90has a male frame91, opposite to the configuration shown in the drawings, the pairs of holes allowing the movement as previously described will be integral with rotary80, not with carriage90.

In general, in the case wherein both structures of a drive assembly have either male or female connection frames, at least one of the two frames will have at least one pair of holes with axes spaced apart by distance d, and these may be located, without distinction, on either one of the two frames of the two structures.

If a third excavation centre-to-centre distance “i3”, different from the previously described excavation centre-to-centre distances “i1” and i2”, were to be generated, for example equal to i1+“d′”, where “d′” is different from and preferably greater than “d”, it will suffice to add at least one additional upper hole95″ and at least one additional lower hole93″ respectively at the same distance “d′” from holes95and93or holes94and96; together with the adjacent ones, the new holes will constitute another pair of upper and lower holes, and therefore may have the following characteristics:the upper pair of holes lie on an arc passing through the centre of hole93in which pin22is inserted to impart the rotation from95to95″; therefore, the lower pair of holes93and93″ lies on a circumference the centre of which is in line with hole95″ in which pin21is inserted for the last rotation that brings the rotary to excavation centre-to-centre distance “i3”;or, vice versa, the lower pair of holes lie on a circumference having as a centre hole95in which pin21is inserted and around which rotation occurs to switch from93to93″; therefore, upper holes95and95″ lie on a circumference having as a centre the axis of hole93″;or hole95″ may be located on the circumference passing through96and having as a centre the centre of hole94—in this case a change will occur directly from the first excavation centre-to-centre distance “i1” to the third excavation centre-to-centre distance “i3” without passing by the second excavation centre-to-centre distance “i2” as in the previously described cases—and therefore holes93″ and94lie on the circumference having as a centre hole95″;or hole93″ lies on the circumference passing through94and having as a centre the axis of hole96, and holes96and95″ lie on a circumference having as a centre the axis of hole93″.