Patent Publication Number: US-9896889-B2

Title: Drilling tool support and method of collaring

Description:
RELATED APPLICATION DATA 
     This application claims priority under 35 U.S.C. §119 to EP Patent Application No. 13198918.8 filed on Dec. 20, 2013, which the entirety thereof is incorporated herein by reference. 
     TECHNICAL FIELD 
     The disclosure relates to a support of a drilling tool used in rock drilling. The support is located at a front end portion of a feed beam and is used to support the tool especially during collaring phase of the drilling. The support has supporting surfaces, which may be set close to outer surfaces of the tool. The support has a supporting position and an idle position between which positions the support may be moved by means of an actuator. The disclosure further relates to a method of collaring wherein a drilling tool is supported by means of a support. 
     BACKGROUND 
     In mines and at other work sites, drilling machines are used for drilling bore holes into rock surfaces and soil. The drilling machine includes a rotating device for rotating a drilling tool during drilling. In many drilling applications the drilling machine also include a percussion device for generating impact pulses to the tool. The drilling tool may be supported during drilling by means of a support. However, the present supports have some defects. 
     SUMMARY 
     An aspect of the invention is to provide a novel and improved support for supporting a drilling tool. A further aspect is to provide a novel and improved method for collaring. 
     The support is characterized in that the support element of the support is located inside a suction housing of a dust removal system at least during drilling, whereby the support element is surrounded by inner surfaces of the suction housing. 
     The method is characterized by surrounding the support by the suction housing at least during the collaring; and generating a relative movement between the support and the suction housing for moving the support to a support position for supporting the drilling tool and to an idle position. 
     The drilling tool is supported with a support, which is located at a front portion of a feed beam. The front portion of the feed beam also includes a suction housing, which is part of a dust removal system. The support is arranged so that it is inside the suction housing at least during the drilling. That is to say that the support element is within the suction housing and is surrounded by inner surfaces of the suction housing at least during the drilling. 
     An advantage of the disclosed solution is that the support may be located close to the front most end of the feed beam. The drilling tool may be supported properly for the collaring drilling, since distance between the support and a drill bit of the drilling tool is short. Improved support of the tool may improve accuracy of the drilling and may prevent tool damages. 
     According to an embodiment, the support element is continuously inside the suction housing. The support element may be designed so that it does not hamper suction flow when being in the idle position. 
     According to an embodiment, the support element is arranged rotationally relative to the suction housing allowing the actuator to turn the support element inside the suction housing to the support position and to the idle position. The support is intended to be turned to the support position for the duration a collaring drilling. When the drilling is initiated properly the need for support decreases and the support may be turned to the idle position. 
     According to an embodiment, the support element is inside the suction housing only during the drilling. 
     According to an embodiment, the support element is within the suction housing at least during the drilling. The suction housing includes a first upper end facing towards a rock drilling device and a second lower end facing towards an opposite direction. During drilling the support element is inside a space confined by inner surfaces of the suction housing. Furthermore, when viewed in an axial direction of the suction housing, the support element is located between the upper end and the lower end of the suction housing. 
     According to an embodiment, the suction housing has a first upper end facing towards a rock drilling device and a second lower end facing towards an opposite direction. The first end of the suction housing includes upper inner surfaces confining a space within the suction housing. The support element is a separate element relative to the upper inner surfaces of the suction housing. The support element is located between the mentioned upper inner surfaces and the second opening of the suction housing. 
     According to an embodiment, the suction housing is a unitary, single piece forming a space inside which the support element is located at least during drilling. 
     According to an embodiment, the support has two or more support elements, which are arranged to move towards each other to provide support for the tool, and are arranged to move to an opposite direction towards an idle position. The support elements may be moved linearly in a transverse direction relative to the longitudinal axis of the drilling tool, for example. Further, the support elements may have curved contact surface facing the drilling tool. 
     According to an embodiment, the support is one single support element. 
     According to an embodiment, the support is one single support element and the support element is provided with an opening allowing the drilling tool to be arranged through the opening, whereby the drilling tool is surrounded by the support element. The support element may be a continuous piece surrounding the drilling tool, or in an alternative solution, the support element may have a gap in the surrounding structure. 
     According to an embodiment, the support is one single support element and the support element is provided with at least two contact surfaces. The support surfaces are connected to each other by means of a rigid mechanical connection. 
     According to an embodiment, the support element has a peripheral configuration. Suction flow inside the suction housing is intensive in a middle portion of the suction housing. When the support element includes the peripheral structure, it is positioned in an edge zone of the suction housing when in the idle position, whereby it does not hamper suction flow. A further advantage of the peripheral structure is that it may allow strong and simple construction. 
     According to an embodiment, the support element has a sleeve-like configuration. The sleeve may have a ring-shaped cross section and may thus have a round or oval periphery. The sleeve-like support element has a front face, an end face and a side surface. The front face and end face have a wall thickness in a transverse direction of the sleeve and the side surface has a length in the longitudinal direction of the sleeve. Further, the length of the sleeve-like support element is at least double the wall thickness of the faces of the support element. 
     The front end of support element is in a direction of a suction flow when the support element is in the idle position. The front end of the sleeve has a substantially small face area, whereby the support element does not hamper suction flow when being in the idle position. However, the sleeve may be rigid since the longitudinal length of the sleeve may be dimensioned so as to provide needed stiffness for the support element. The longitudinal dimension of the sleeve does not cause flow resistance to the suction flow inside the suction housing when the support element is in the idle position. 
     According to an embodiment, the support element has a sleeve-like configuration and the support element is provided with a first contact surface and a second contact surface, which are located on opposite sides of the sleeve. Side surfaces of the sleeve are provided with a first opening and a second opening, which serve as a first contact surface and a second contact surface. The first and the second opening are located on opposite sides of the sleeve-like support element relative to each other. The first opening opens to the front face of the support element and the second opening opens to the rear face of the support element. The first and second opening may be a longitudinal groove. Alternatively, the first and second opening may be notches. The groove or the notch may have a curved bottom surface, which serves as the contact surface. Due to the curved contact surface, possible contact between the tool and the contact surface does not cause point load between the components but instead larger contact area may exist. 
     According to an embodiment, the support element has a peripheral configuration. Thus, the support element may have a sleeve-like form, for example. Further, the support element may be provided with one or more sensors or measuring devices for measuring the drilling tool and drilling parameters. The support element may include measuring means for determining forces directed from the drilling tool to the support element in situations when the drilling tool is physically guided by means of the support element. This type of measuring may be executed when the support element is in a support position. Since the support element is a uniform structure around the drilling tool, it is possible to provide the peripheral support element with a measuring coil allowing measuring impact pulses conveyed in the drilling tool, for example. This type of measuring may be executed when the support element is in an idle position. 
     According to an embodiment, the support element is supported to the suction housing by means of two rotational axles, which are located on opposite sides and have a common central axis. The two rotational axles ensure rigid support for the support element. 
     According to an embodiment, the support element is supported to the suction housing by means of one single rotational axle. The rotational axle may be dimensioned to be rigid enough. 
     According to an embodiment, the support element is rotated between a horizontal position and vertical position. The horizontal position of the support element serves as the idle position and the vertical position serves as the support position. The support element may be turned 90°. 
     According to an embodiment, the actuator is a pressure medium operated device. Hydraulic pressure fluid and compressed air is typically available in a rock drilling unit, whereby use of the pressure medium operated actuator does not need any special arrangements. 
     According to an embodiment, the actuator is a pressure medium operated cylinder. Cylinders are reliable and inexpensive force devices. 
     According to an embodiment, the actuator is a pressure medium operated motor. 
     According to an embodiment, the actuator is an electrical motor. 
     According to an embodiment, the actuator is an electrical linear force member. 
     According to an embodiment, the support has at least one transfer element for transmitting the transfer movement of the actuator to the support element. The transfer element may have a crank-like configuration. 
     According to an embodiment, the support is arranged at a distal end portion of a feed beam of a rock drilling unit. At an outermost end of the feed beam is a contact element for supporting the feed beam against a surface being drilled. The contact element of the feed beam may be a claw, a pad, a support plate or any other physical supporting element, which defines an outermost end portion of the feed beam. The suction housing is located on the feed beam and it comprises openings allowing the drilling tool to be fed through it. The support is located between the contact element of the feed beam assembly and an upper opening of the suction housing. 
     According to an embodiment, the suction housing is movable relative to the feed beam assembly. The support is continuously inside the suction housing. Thus, the support is moving together with the suction housing. 
     According to an embodiment, the suction housing is movable relative to the feed beam assembly. The suction housing has an idle position and an operative position. In the idle position the suction housing is at a greater distance from the contact element as compared to the operational position. The support is mounted to the distal end portion of the feed beam assembly and is located between the contact element and the suction housing. The support is surrounded by the suction housing when the suction housing is moved to the operational position closer to the contact element. 
     According to an embodiment, the suction housing has a rigid base and a flexible contact portion at an outermost end of the suction housing. Thus, the first opening is defined by the rigid base and the second opening is defined by the flexible contact portion. The flexible contact portion settles against the surface being drilled and prevents dust from escaping to the surrounding air. The flexible contact portion may be made of flexible material such as rubber or plastic. 
     According to an embodiment, the support is intended to be used in percussion drilling. 
     According to an embodiment, the support is intended to be used in rotary drilling. 
     According to an embodiment, the support is intended to be used in a surface drilling device. 
     According to an embodiment, the support is intended to be used in an underground drilling device. 
     According to an embodiment, the support element is intended to serve as a flow guide for directing suction flow inside the suction housing. The support element may direct the flow towards a discharge opening of the suction housing. Alternatively, or in addition to, the support element may be configured to direct the suction flow or at least part of it away from outer surfaces of a drilling tool, whereby abrasive attack of the drilling cuttings of the suction flow is decreased and life time of the drilling tool may be longer. Geometry of the support element may be designed so that the desired guiding is achieved. Alternatively, or in addition to, the support element may be turned inside the suction housing to a turning position, where the desired guiding is achieved. 
     The above-disclosed embodiments can be combined to form desired solutions provided with necessary features disclosed. The foregoing summary, as well as the following detailed description of the embodiments, will be better understood when read in conjunction with the appended drawings. It should be understood that the embodiments depicted are not limited to the precise arrangements and instrumentalities shown. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a side view of a rock drilling rig provided with a drilling unit. 
         FIG. 2  is a schematic side view of a front portion of a feed beam provided with a suction housing and a support. 
         FIG. 3  is a schematic view of a support in an idle position, and in  FIG. 4  the same support is in an operative support position. 
         FIGS. 5 and 6  are schematic views of a support in idle and support position and when seen in longitudinal direction of a drilling tool. 
         FIGS. 7 and 8  are schematic views of a turning mechanism of a support. 
         FIGS. 9 and 10  are schematic views of a suction housing seen from the front end of a feed beam, and wherein inside the suction housing is a support element in an idle position and in a support position. 
         FIG. 11  is a schematic view of support seen from above, wherein the support includes two support plates allowed to be turned between a support position and an idle position. 
         FIG. 12  is a schematic side view of the support shown in  FIG. 11 . 
         FIG. 13  is a schematic side view of a front portion of feed beam provided with a support having fixed position and a suction housing being movable relative to the support. 
         FIGS. 14 and 15  are schematic views of a support seen in longitudinal direction of a drilling tool and illustrating a support and idle positions of support elements of the support. 
     
    
    
     For the sake of clarity, the figures show some embodiments of the disclosed solution in a simplified manner. In the figures, like reference numerals identify like elements. 
     DETAILED DESCRIPTION 
       FIG. 1  shows a rock drilling rig  1  including a rock drilling unit  2 , which may be connected by means of a boom  3  to a movable carrier  4 . The drilling unit  2  may have a feed beam  5  and a rock drilling machine  6  supported thereon. The rock drilling machine  6  may be moved on the feed beam  5  by means of a feed device  7 . The rock drilling machine  6  has a shank  8  at a front end of the rock drilling machine  6  for connecting a tool  9 . The tool  9  may include one or more drill rods  10  and a drill bit  11  located at a distal end of the tool  9 . 
     The rock drilling machine  6  further includes a rotating device  12  for rotating the shank  8  and the tool  9  connected to the shank  8 . When the rock drilling is based on rotation R and feed F of the tool then the drilling is known as rotary drilling. However, the rock drilling machine  6  may also have an impact or percussion device  13  for generating impact pulses to the tool  9 . When the rock drilling machine  6  is provided with the percussion device  13 , which is located on an opposite end of the tool  9  as compared to the drill bit  11 , the drilling is known as top-hammer drilling. 
     At a drilling site, one or more drill holes  14  are drilled with the drilling unit  2 . The drill holes  14  may be drilled in a vertical direction, as is shown in  FIG. 1 , or alternatively, in a horizontal direction or in an angular direction. The drill holes  14  may be drilled in a rock material or soil. 
     During drilling dust and drilling cuttings are formed, wherefore the rock drilling rig  1  is provided with a drill hole flushing system allowing feeding of flushing fluid through the drilling tool  9  to the drill hole  14 . The rock drilling rig  1  may also include a dust collection system for removing the produced dust from an opening of the drill hole  14 . At a front portion  5   a  of the feed beam  5  is a suction housing  15  inside which a negative pressure is formed through a suction line  16 . The dust is conveyed through the suction line  16  to the carrier  4  where particles are separated from the air. The suction housing  15  has a discharge port  17  for connecting the suction line  16 . As can be noted, the drilling tool  9  passes through the suction housing  15 . At a front most end of the feed beam  5  is a contact element  18  by means of which the feed beam  5  is supported to a surface being drilled. At least the feed beam  5  and the contact element  18  define a feed beam assembly  19 . 
     The rock drilling unit  2  includes a support S for providing support for the tool  9  at the front portion  5   a  of the feed beam  5 . The support S is located between the contact element  18  and an upper end of the suction housing  16 , as it is shown in  FIG. 1 . If the support is in a location  20  shown in dotted lines, then the support is located at a relative long distance from the front most end of the feed beam assembly  19 , whereby no proper support is achieved. 
       FIG. 2  illustrates a front portion  5   a  of a feed beam  5 . A suction housing  15  may be arranged movably relative to the feed beam  5 . The suction housing  15  may be mounted to a cradle  21 , which is supported on the feed beam  5 . The cradle  21  may be moved by means of a cylinder  22 . During positioning of the feed beam  5 , the suction housing  15  may be in an upper position and during drilling it may be in a lower position. 
     Inside the suction housing  15  is arranged a support element SE of a support S. The support S may move along the suction housing  15 . The support elements SE may be actuated by an actuator  23 , which may be a cylinder, for example. The actuator  23  may affect operation of the support elements SE through a transfer element  24 , which may have a crank mechanism, for example. The suction housing  15  has a first upper opening  25  facing a drilling machine and a second lower opening  26  facing the drilled surface. The tool passes through the openings  25  and  26 . The support element SE is located within a space formed by inner surfaces of the suction housing  15 . Further, as shown in  FIG. 2 , the support element SE is located axially between the first upper opening  25  and the second lower opening  26  of the suction housing  15 . 
       FIG. 3  discloses a support S including a sleeve-like support element SE. The support element SE may be turned around rotational axles  27 . The rotational axles  27  may be supported to a suction housing or to any other support structure. The support element SE may be turned by means of an actuator  23  and a transfer element  24 . The support element SE is shown in  FIG. 3  in an idle position IP and in  FIG. 4  in operative support position SP. The sleeve like support element SE has a cylindrical side surface  28  and ring shaped front face  29  and end face  30 . The support element SE is also provided with a first contact surface  31   a  and second contact surface  31   b , which are located on opposite sides. 
     The side surface  28  has a first opening  32   a  and a second opening  32   b . The first opening  32   a  opens to the front face  29  and the second opening  32   b  opens to the end face  30 . The bottom of the first opening  32   a  serves as the first contact surface  31   a  and the bottom of the second opening  32   b  serves as the second contact surface  31   b . In the idle position IP the sleeve like support element SE is in a horizontal position and the drilling tool  9  passes through it. The contact surfaces  31   a  and  31   b  are facing away from the drilling tool  9 . The support element SE may be turned to a vertical position shown in  FIG. 4 , whereby the contact surfaces  31   a  and  31   b  are moved close to the outer surface of the drilling tool  9 . The drilling tool  9  then passes through the first opening  32   a  and the second opening  32   b . The actuator  23  may be a hydraulic cylinder and the produced linear movement of the cylinder may be converted to a rotational movement by means of a crank mechanism serving as the transfer element  24 . 
       FIGS. 5 to 8  disclose the support S in other directions/views. The features and operation of the support is disclosed above. 
     In  FIGS. 9 and 10  the support S is integrated to a structure of a suction housing  15 . A support element SE of the support S is located inside the suction housing  15 . An idle position IP and support position SP are shown in  FIGS. 9 and 10 . The suction housing  15  may be supported to a feed beam by means of slide elements  33 . 
       FIG. 11  discloses an alternative support S having two separate support elements SE 1  and SE 2 , which are plate-like objects and are allowed to be turned relative to transverse rotating axles  27 . Front ends of the support elements SE 1  and SE 2  are provided with curved contact surfaces  31   a  and  31   b . The support elements  31   a  and  31   b  may be turned by an actuator, which may be a hydraulic or electrical motor, for example. 
       FIG. 12  shows the support S of  FIG. 11  from one side. The idle position ID is indicated by dotted lines. In connection with the support may be a suction housing  15 , which is also shown in dotted lines. The suction housing  15  may be arranged to move linearly together with the support S or alternatively only the suction housing  15  moves and the support S is not moved.  FIG. 12  further shows that at an upper end portion of the suction housing may be a guide plate  34  for directing the suction flow towards a discharge port  17 . 
       FIG. 13  discloses a solution where a support S is not moved together with suction housing  15 . Instead the support S is supported to a lower portion  5   a  of the feed beam by means of suitable support brackets  35 . The support S may have any suitable basic structure. At least for the duration of collaring and normal drilling the suction housing  15  is moved towards a surface to be drilled and as a consequence of that, the suction housing  15  will slide over the support S and surround it. At a lower end on the suction housing  15  may be a flexible portion  36  which seals gaps between the suction housing  15  and the surface. The flexible portion  36  may also reshape and allow the movement of the suction housing  15  relative to the support S. 
       FIGS. 14 and 15  show in a simplified manner an additional support S provided with two support elements SE 1  and SE 2 , which are moved linearly in a transverse direction relative to the tool  9 . 
     Although the present embodiment(s) has been described in relation to particular aspects thereof, many other variations and modifications and other uses will become apparent to those skilled in the art. It is preferred therefore, that the present embodiment(s) be limited not by the specific disclosure herein, but only by the appended claims.