Method of mounting a Kelly bar on a drilling machine, relevant mounting tool and a drilling machine equipped with such mounting tool

Abstract

A method of mounting a kelly bar on a drilling machine includes a step of installing a mounting tool between the rod of a pull-down cylinder and a rotary carriage of the drilling machine. Once the mounting tool has been installed, the drilling machine can be set up with a kelly bar that is longer than the usual kelly bars.

Claims

1. A method of mounting a kelly bar on a drilling machine, the method comprising: setting a pull-down cylinder containing a rod in an extended condition to bring a rotary carriage and a drilling rotary to a distance H or to a position close to the distance on a guide tower; locking the rotary carriage on the guide tower; disengaging the rotary carriage from the pull-down cylinder; switching the pull-down cylinder from the extended condition to a retracted condition by an extent at least equal to a length of a mounting tool provided with at least one traction element; installing the mounting tool between the rod of the pull-down cylinder and the rotary carriage; unlocking the rotary carriage on the guide tower; switching the pull-down cylinder to the extended condition to bring the drilling rotary to a distance H1 greater than the distance H; connecting a rope to the kelly bar; lifting the kelly bar by operating a main winch of the drilling machine, up to bring a lower end of the kelly bar above the drilling rotary; aligning the kelly bar with an annular passage of a drive sleeve of the drilling rotary; retracting the rod of the pull-down cylinder to obtain a rise of the rotary carriage and the drilling rotary up to a point, which has a distance from a head of the guide tower that is equal to or less than the distance H, the retraction of the rod of the pull-down cylinder determining a sliding engagement of the annular passage of the drive sleeve of the drilling rotary to the kelly bar; locking the rotary carriage on the guide tower; disassembling the mounting tool by disengaging the at least one traction element between the rod of the pull-down cylinder and the rotary carriage; switching the pull-down cylinder in to the extended condition; connecting the rod of the pull-down cylinder to the rotary carriage; and unlocking the rotary carriage on the guide tower, wherein the head of the guide tower is provided with at least one pulley for the rope from the main winch of the drilling machine to engage one end of the kelly bar, directly or indirectly, through a rotatable element, to move the kelly bar; the drilling rotary is slidingly engaged to the guide tower through the rotary carriage and has the driving sleeve with the annular passage for inserting and engaging the kelly bar; the pull-down cylinder is engaged to the guide tower; the pull-down cylinder is engaged to the rotary carriage and the drilling rotary via the rod of the pull-down cylinder to move the rotary carriage and the drilling rotary along the guide tower; the retracted condition is a condition in which the rod of the pull-down cylinder is disposed within the pull-down cylinder; the extended condition is a condition in which the rod of the pull-down cylinder is disposed outside the pull-down cylinder; and the distance H is defined by a maximum downward sliding of the rotary carriage controlled by the rod of the pull-down cylinder in the extended condition.

2. The method according to claim 1, further comprising: before connecting the rope to the kelly bar, carrying out a forward inclination of the guide towel; and before or simultaneously with aligning the kelly bar to the annular passage of the drive sleeve of the drilling rotary, straightening the guide tower to a vertical direction.

3. The method according to claim 1, further comprising: before retracting the rod of the pull-down cylinder to return the drilling rotary to the distance H, moving the kelly bar, by unwinding the rope to lead the kelly bar to cross the annular passage of the drive sleeve of the drilling rotary.

4. The method according to claim 1, wherein: at least one of said locking the rotary carriage on the guide tower includes installing one or more stop pads on guides of the guide tower; and at least one of said unlocking the rotary carriage on the guide tower comprises disassembling the one or more stop pads from the guides of the guide tower.

5. The method according to claim 1, wherein said installing the mounting tool between the rod of the pull-down cylinder and the rotary carriage includes: connecting one end of a rigid traction element of the mounting tool to the rod of the pull-down cylinder using at least one pin; and connecting the other end of the rigid traction element of the rigid mounting tool to the rotary carriage using at least one pin.

6. The method according to claim 1, wherein said installing the mounting tool between the rod of the pull-down cylinder and the rotary carriage includes: connecting one end of a first flexible traction element of the mounting tool to the rotary carriage using at least one pin; connecting another end of the first flexible traction element of the mounting tool to one end of a second rigid traction member of the mounting tool using at least one pin; and connecting another end of the second rigid traction element of the mounting tool to one end of the rod of the pull-down cylinder using at least one pin.

7. The method according to claim 6, further comprising: after said installing the mounting tool and before said unlocking the drilling rotary, adjusting the pull-down cylinder so that the pull-down cylinder is in the retracted condition of a measure sufficient to put under tension the first flexible traction element of the mounting tool.

8. A drilling machine, comprising: a guide tower equipped with a head provided with at least one pulley; a main winch equipped with a rope to engage, directly or indirectly, through a rotating element, one end of a kelly bar to move the kelly bar; a drilling rotary slidingly engaged to the guide tower via a rotary carriage and having a driving sleeve having an annular passage for inserting and engaging the kelly bar; a pull-down cylinder, wherein the pull-down cylinder is engaged to the guide towel, the pull-down cylinder has a rod and is engageable to the rotary carriage and the drilling rotary via the rod to move the rotary carriage and the drilling rotary along the guide tower, the pull-down cylinder switches between a retracted condition in which the rod is provided inside the pull-down cylinder and an extended condition in which the rod is provided outside the pull-down cylinder, and the pull-down cylinder defines, in the extended condition, a distance H of maximum downward sliding of the rotary carriage; and a mounting tool for mounting the kelly bar on the drilling machine, wherein the mounting tool contains at least one traction element installable between the rod of the pull-down cylinder and the rotary carriage of the drilling machine and is installed between the rod of the pull-down cylinder and the rotary carriage.

Description

(1) The characteristics and advantages of the mounting method and the relevant mounting tool will be more evident from the following description, which is a non-limiting example, referring to the attached schematic drawings in which:

(2) FIG. 1 is a schematic side elevation view of a drilling machine equipped with a kelly bar, in accordance with the present invention;

(3) FIGS. 2A, 2B, 2C are schematic side elevation views of a guide tower/kelly bar assembly of the drilling machine in FIG. 1 illustrating the steps of mounting the kelly bar on the respective guide tower without mounting tool;

(4) FIG. 3 is a perspective view of the guide tower of the drilling machine illustrated in FIG. 1 equipped with a mounting tool in accordance with a first embodiment variant of the present invention;

(5) FIG. 4 is a perspective view of the guide tower of the drilling machine illustrated in FIG. 1 equipped with a mounting tool in accordance with a second embodiment variant of the present invention;

(6) FIGS. 5A and 5B and 5C are schematic side elevation views of the guide tower in FIG. 4 illustrating a sequence of use of the relevant mounting tool provided.

(7) With reference to FIG. 1, the number 100 generally indicates a drilling machine.

(8) As can be seen in FIG. 1, the drilling machine 100 is equipped with a guide tower 101 which is inclinably constrained to a base body 100a consisting of an undercarriage 100b arranged to translate the drilling machine 100 on the ground and of a turret 100c superimposed on the undercarriage 100b. The turret 100c can be rotated around a vertical axis and is arranged to support the guide tower 101 by means of a hinge connection or a dedicated kinematic mechanism.

(9) The guide tower 101 is equipped with a pull-down cylinder 102 arranged to slide a rotary carriage 103 along the guide tower itself. The rotary carriage 103 is directly or indirectly connected by means of further components which will be described below to one end of the pull-down cylinder 102 by means of a respective fixing pin 104.

(10) A drilling rotary 105 is connected to the rotary carriage 103, while a drill head 106 is disposed at the top of the guide tower 101. The head 106 houses some components which will not be mentioned as they are not relevant for the purposes of the invention, and a pulley 107, on which a rope 108 slides which is moved by a main winch 109 (FIG. 1) of the drilling machine 100. At one end of the rope 108 there is fixed a rotatable element 111 which is in turn connected to an upper end of a digging battery or, more commonly referred to as a kelly bar 110, already described in detail in connection with the prior art. In detail, the rotatable element 111 is connected to an upper end of an innermost hollow telescopic cylindrical element of the kelly bar 110.

(11) The kelly bar 110 consists of an assembly of hollow cylindrical elements of different diameters that are coaxially coupled. Each cylindrical element is equipped with axial abutments located at the ends which prevent the complete disengagement of one element with respect to the adjacent ones. Each cylindrical element is equipped with ribs which, during rotation, come into contact with the ribs of the other cylindrical elements of the kelly bar, thus allowing the transmission of torque from the outermost cylindrical element up to the innermost cylindrical element. At the top of the outermost cylindrical element of the kelly bar, there may be a guide element equipped with a bearing that slides on corresponding sliding guides of the guide tower of the drilling machine 100 so as to keep the kelly bar 110 on the correct vertical axis. The bearing ensures free rotation of the kelly bar 110.

(12) The kelly bar 110 may further be connected to the guide tower 101 of the drilling machine 100 by means of an element or upper guide carriage 112, which also slides longitudinally, like the rotary carriage 103, on corresponding guides 113 of the guide tower 101. In the event that it is necessary to mount a kelly bar 110 having a length less than a distance H, defined as the distance between the top plane of the drilling rotary 105 and the bottom plane of the head 106, the traditional mounting method, already described in detail in relation to the prior art, can be carried out.

(13) Conversely, in the event that it is necessary to mount a kelly bar 110 having a length greater than the distance H, without having to disconnect the drilling rotary 105 from the guide tower 101 when the drilling machine 100 is in a working configuration, the relevant mounting method involves the use of a suitable mounting tool 200 (FIGS. 3, 4, 5B and 5C) which will be described below.

(14) With reference to the mounting of a kelly bar 110 having a length less than the above-mentioned distance H, schematically represented in FIGS. 2A, 2B and 2C, the rotary carriage 103, carrying the peroration rotary, 105 is directly fixed to the pull-down cylinder 102 by means of the fixing pin 104.

(15) The rotary carriage 103 and the drilling rotary 105 are brought to the lowest possible position by fully extending the pull-down cylinder 102. The maximum distance H between the top plane of the drilling rotary 105 and the bottom plane of the head 106 is then obtained.

(16) With reference to FIG. 2A, the kelly bar 110 is initially placed on the ground or, possibly on special stands, in an almost horizontal or horizontal position. The guide tower 101 is brought at the kelly bar 110 and can be inclined slightly forward, towards the kelly bar 110 itself. By means of the main winch 109, which is not shown as it is known, the rope 108 is lowered until the end of the rope 108 is close to the rotatable element 111.

(17) After having hooked, by means of a special pin, the rotatable element 111 to the end of the rope 108, the kelly bar 110 is slowly raised until it reaches a vertical position, as shown in FIG. 2B. At this point, the alignment of the upper guide element 112 is carried out, if applicable.

(18) Next, the guide tower 101 is slowly brought to a vertical position and the kelly bar 110 is lowered until it engages, in a known manner, with the drilling rotary, as shown in FIG. 2C.

(19) Alternatively, the kelly bar 110 may be held in a suspended position and the drilling rotary 105 may be raised until it engages, in a known manner, with the kelly bar 110.

(20) As can be seen from FIGS. 1, 2A, 2B and 2c, the maximum length that the kelly bar 110 may have in this case in order to proceed with the mounting as described above must be less than the distance H.

(21) Instead, with reference to the mounting of a kelly bar 110 having a length greater than the aforementioned distance H, the mounting tool 200 used may have different configurations.

(22) In accordance with a first embodiment of the present invention, illustrated in FIG. 3, the mounting tool 200 comprises a traction element 301 which may be rigid or flexible. In FIG. 3, the drilling rotary 105 is not shown to allow for a better view of the traction element 301 and the fixing thereof to the rotary carriage 103, but it is to be understood that in the condition of mounting the kelly bar 110, the drilling rotary 105 is connected to the rotary carriage 103. The traction element 301 which is mounted between the rod of the pull-down cylinder 102 and the rotary carriage 103. In detail, the ends of the traction element 301 are fixed, by means of corresponding pins 302 and 303, to the rod of the pull-down cylinder 102 and to the rotary carriage 103 respectively.

(23) The mounting of the traction element 301, during the machine set-up phase, makes it possible that following a complete extension of the pull-down cylinder 102 the rotary carriage 103 and the drilling rotary 105 itself can be lowered until they protrude below the lower end of the guide tower 101 therefore at a lower level than the level normally attainable in the absence of the traction element 301.

(24) In accordance with a second embodiment illustrated in FIG. 4, the mounting tool 200, comprises more than one traction element 401, 402 interposed between the rod of the pull-down cylinder 102 and the rotary carriage 103. In particular, the mounting tool 200 comprises a first traction element 401, preferably flexible, and a second rigid traction element 402 that are connected to each other by means of a connection pin 403. The second traction element 402 is interposed between the rod of the pull-down cylinder 102 and the first traction element 401 in such a way that it is, in an operating condition, positioned above the first traction element 401 and the drilling rotary 105.

(25) In detail, the second traction element 402 has a first end connected to the rod of the pull-down cylinder 102 by means of a pin 302 and a second end connected to a respective first end of the first traction element 401 by means of the pin 403. The first traction element 401 has a second end opposite with respect to the first and second traction element 402, which is connected to the rotary carriage 103 by means of a pin 303.

(26) The flexibility of the first traction element 401 makes it easier to connect it to the rotary carriage 103. In fact, the operator in charge of the step of setting up the drilling machine 100 has the possibility, when inserting the connection pin 303, of slightly deforming the first flexible traction element 401 by means of his manual force, in order to mate the insertion seats of said pin 303.

(27) With reference to FIGS. 5A, 5B and 5C, there is illustrated a sequence of use of the mounting tool 200 and, accordingly, the relevant method of mounting, in accordance with the present invention.

(28) For the sake of clarity, the undercarriage 100b and the body 100a of the drilling machine are not shown in FIGS. 5A-5C, but it should be understood that the guide tower 101 is connected to the drilling machine 100.

(29) As can be seen in the schematic FIG. 5A, the guide tower 101 of the drilling machine 101 is shown without the kelly bar 110 and without the mounting tool 200, with the drilling rotary 105 in the lowest permitted position on the guide tower 101 determined by the sole actuation of the pull-down cylinder 102 which is in the maximum extension condition.

(30) In the condition illustrated in FIG. 5A, a number of anti-sliding pads 501, are fixed on the guide tower 101 at a lower level than the rotary carriage 103 so as to stop the descent by gravity of the latter and the drilling rotary 105.

(31) The anti-sliding pads 501 may consist of mechanical stop abutments which are fixed to the guide tower 101 or to the guides of the tower guide 101 by screw, pin or clamp engagement means.

(32) Continuing the steps of the method of mounting the kelly bar 110, the fixing pin 104 connecting the rotary carriage 103 to the pull-down cylinder 102 is removed and the rod of the pull-down cylinder 102 is retracted, at least partially. In this situation, the drilling rotary 105 is temporarily kept locked by at least one anti-sliding pad 501 that prevents it from descending. With reference to the mounting tool 200 illustrated in FIG. 3, the traction element 301 is installed in a position interposed between the pull-down cylinder 102 and the rotary carriage 103 by connecting the ends of the traction element 301 to the pull-down cylinder 102 and to the rotary carriage 103 by means of respective fixing pins 302, 303.

(33) With reference instead to the mounting tool 200 illustrated in FIG. 4, the first and second traction element 401,402 are installed in a position interposed between the pull-down cylinder 102 and the rotary carriage 103, proceeding according to the sequence below.

(34) The second rigid traction element 402 is connected to the pull-down cylinder 102 by means of the respective pin 302.

(35) The first end of the first flexible traction element 401 is connected to the second rigid traction element 402 by means of the pin 403.

(36) The second end of the first flexible traction element 402 is connected to the rotary carriage 103, by means of the fixing pin 303.

(37) The anti-sliding pads 501 are removed such that at least one traction element 401, 402, preferably the first traction element 401, is placed under traction by the weight of the drilling rotary 105, while the latter is retained by the pull-down cylinder 102.

(38) Advantageously, the pull-down cylinder 102 may be retracted by a sufficient amount to place the first traction element 401 under traction before removing the anti-sliding pads 501.

(39) Once the anti-sliding pads 501 have been removed, the pull-down cylinder 102 is extended to cause the rotary carriage 103 and the drilling rotary 105 to descend along the guide tower 101 until a “set-up configuration” of the drilling machine 100 is reached in which the drilling rotary 105 is at a distance H1 greater than the distance H. In this case, the rotary carriage 103 is guided, only for a portion of its height, by the guides of the guide tower 101.

(40) More in detail, the upper guide seats of the rotary carriage 103 are fully engaged along their entire length to the guides of the guide tower 101, while the lower guide seats of the rotary carriage 103 may be engaged to the guide tower 101 even for only a limited part of their length.

(41) The position that is reachable by the drilling rotary 105 illustrated in FIG. 5B and therefore the length of the section of the rotary carriage 103 protruding below the guides of the guide tower 101 and the value of the distance H1 depend on the length of the traction element 301 or of the traction elements 401, 402 of the mounting tool 200 which is interposed between the pull-down cylinder 102 and the rotary carriage 103. The distance H1, reachable by means of the mounting tool 200, allows mounting kelly bars 110 having a length equal to the distance H1, i.e. Increased with respect to the length of the kelly bars 110 normally used on such drilling machines 100.

(42) Since the mounting tool 200 between the rotary carriage 103 and the pull-down cylinder 102 is used on the drilling machine 100 only during the set-up of the same and not in the working configuration, the condition of FIG. 5B with the guide seats of the rotary carriage 103 only partially engaged to the guide tower 101 cannot be achieved during the use of the drilling machine 100.

(43) When the drilling rotary 105 is at distance H1, the rope 108 may be connected to the kelly bar 110 to lift the latter through actuation of the main winch 109 of the drilling machine 100. The kelly bar 110 is then lifted until its lower end is brought above the drilling rotary 105. When lifting the kelly bar 110, the guide tower 101 may be kept slightly inclined forward to avoid undesirable collisions between the kelly bar 110, the drilling rotary 105 and any other parts of the drilling machine 100.

(44) Next, the kelly bar 110 is aligned with an annular passage of the drive sleeve of the drilling rotary 105 to make them coaxial.

(45) During this last phase, it is possible to adjust the inclination of the guide tower 101 in order to bring it to a position close to the vertical and to favour the coaxiality of the kelly bar 110 with the annular passage of the drive sleeve of the drilling rotary 105.

(46) Once the alignment has been made, the rod of the pull-down cylinder is retracted to achieve a rise of the rotary carriage 103 and of the drilling rotary 105 up to a distance from the head that is equal to or less than the distance H. During this rise, the annular passage of the drive sleeve of the drilling rotary 105 engages on the kelly bar 110 and rises sliding externally and coaxially thereto.

(47) In an alternative variant of the method, before retracting the rod of the pull-down cylinder to return the rotary to the distance H, the kelly bar 110 can be moved by unwinding the winch rope 109, so that the kelly bar 110 descends through the annular passage of the drive sleeve of the drilling rotary 105 with a relative translation motion with respect to the rotary itself. At this point, as shown in FIG. 5C, at least one anti-sliding pad 501 is mounted, on the guide tower 101, below the rotary carriage 103 so as to prevent the drilling rotary 105 from sliding downwards.

(48) Once the drilling rotary 105 is locked, it is possible to disassemble the mounting tool 200 by disengaging the traction element 301 or the traction elements 401, 402 from the drilling machine 100. In detail, the disassembly of the mounting tool 100 is performed by removing the pin between the rotary carriage 103 and the relevant pull-down element 301, 401 and by removing the pin between the pull-down cylinder 102 and the relevant pull-down element 301, 402.

(49) After removal of the mounting tool 200, the pull-down cylinder 102 is extended up to the seat of the pin on the rotary carriage 103. At this point, the relevant pin 104 is inserted between the rod of the pull-down cylinder 102 and the rotary carriage 103.

(50) All anti-sliding pads 501 are again removed to allow the drilling rotary 105 to slide together with the rotary carriage 103 along the guide tower 101.

(51) The digging tool can now be connected to the kelly bar 110 in order to put the machine in the “working configuration”, i.e. ready to dig into the ground. The mounting method and the mounting tool described so far solve the problems encountered with the prior art and achieve important advantages.

(52) First of all, according to the present invention it is possible to mount kelly bars of longer lengths than those normally used without having to disassemble or remove any component of the drilling machine, such as the drilling rotary or the rotary carriage. On the one hand, this allows improving all those drilling machines intended for use in environments and workspaces that are limited in height, such as areas under bridges, buildings or other similar existing structures, and on the other hand, it avoids or minimises all downtime and idle times for mounting the kelly bar.

(53) Furthermore, it should be considered that the mounting method and the relevant mounting tool according to the present invention make it possible to quickly set up drilling machines with longer kelly bars in order to be able to reach high digging depths while keeping the overall dimensions in height rather limited.