Abstract:
An automatic loader ( 10 ) for drill rods ( 11 ) adapted to be associated with a boring machine having a guide and drive assembly ( 12 ) for the drill rods ( 11 ) includes at least a store ( 13 ) containing a plurality of drill rods ( 11 ) and a movement assembly ( 14 ) that is able to selectively remove, one at a time, the drill rods ( 11 ) from the store ( 13 ) to position them on the guide and drive assembly ( 12 ). The movement assembly ( 14 ) is arranged in an intermediate position between the store ( 13 ) and the guide and drive assembly ( 12 ), so as to not interfere with the latter during the removal of the drill rods ( 11 ) from the store ( 13 ).

Description:
FIELD OF THE INVENTION 
     This invention concerns an automatic loader for drill rods employed in association with boring machines comprising a guide and drive assembly, on which the drill rods are mounted and made to rotate in order to drill the ground. 
     The automatic loader according to the invention comprises a store, on which a plurality of drill rods are temporarily arranged, located adjacent to the guide and drive assembly of the boring machine. 
     A pick-up mechanism, cooperating with the store, is provided to selectively pick up one of the rods and position it on the guide and drive assembly. 
     BACKGROUND OF THE INVENTION 
     Conventional boring machines, employed to bore the ground, comprise a guide and drive assembly able to make the drill rods rotate; the drill rods are several meters long and at the lower end a drilling tool is associated to drill the ground. 
     In order to perform drilling operations of several tens of meters in depth, it is necessary to attach a plurality of drill rods one after the other, until the specified depth is reached. 
     The drill rods are normally prepared in appropriate containers, or stores, arranged at the side of the boring machine; they are mounted onto the guide and drive assembly one by one, by means of movement means, which are at least partly automatic. 
     The movement means, however, often do not ensure a secure grip of the drill rods during the pick-up step, and make it difficult to position the drill rods precisely on the guide and drive assembly. 
     The state of the art includes a boring machine wherein the loader is of the rotary type and is mounted on the frame, on one side with respect to the guide and drive assembly, while the movement means are mounted on the opposite side. 
     In this embodiment, however, the combination of the boring machine and the loader is very bulky. 
     With this machine, moreover, given the particular arrangement of the different assemblies, it is not possible to prepare a new drill rod while the boring machine is drilling, due to the interference which the movement means would create with the guide and drive assembly. 
     Therefore, the time required to load the drill rods is substantially lengthened, which does not make possible to optimize the working cycle of the boring machine. 
     The present Applicant has devised and embodied this invention to overcome these shortcomings and to obtain other advantages. 
     SUMMARY OF THE INVENTION 
     The invention is set forth and characterized in the main claim, while the dependent claims describe other characteristics of the main embodiment. 
     The purpose of the invention is to achieve a loader which will allow to perform the operations of arranging the drill rods on the guide and drive assembly easily, quickly and completely automatically, limiting to a minimum the inactive times of the boring machine with which it is associated. Another purpose of the invention is to achieve a loader for drill rods which is extremely versatile, that is, which can be used for drill rods of different lengths and diameters, and which has a limited bulk so that the relative boring machine can be used even in limited operating spaces. 
     The automatic loader according to the invention is associated on one side of the guide and drive assembly of the relative boring machine and comprises at least a store to contain the drill rods and a movement device arranged in an intermediate position between the store and the guide and drive assembly. 
     To be more exact, the movement device comprises at least an oscillating arm associated at the end with a gripper member which can be selectively activated by actuator means of a pneumatic or oil-dynamic type. 
     The gripper member is also able to rotate with respect to the relative oscillating arm, to cooperate selectively with the rod container store and with the guide and drive assembly. 
     In a preferential embodiment, the gripper member comprises jaws of an interchangeable type, which can be replaced according to the diameter of the drill rods which have to be moved. 
     In an advantageous embodiment, the container store is also of the rotary type, so that it can be selectively arranged with the drill rod to be used facing towards the movement device. 
     According to the invention, the drill rods are picked up from the container store and arranged in an operating position on the guide and drive assembly by a coordinated movement of the oscillating arm and the gripper member. 
     Thanks to the position of the movement device, it is possible to pick up and prepare the drill rods for loading even while the boring machine is drilling, since there is no danger of interference between the movement device and the guide and drive assembly. 
     As soon as the drilling step is finished, the new rod to be loaded can thus be mounted immediately onto the guide and drive assembly, so that the inactive time of the boring machine is reduced to a minimum. 
     During the movement of the container store to the guide and drive assembly, the drill rods are always gripped by the gripper member, which substantially prevents any risk of the drill rods falling. 
     The automatic loader according to the invention is also extremely compact and suitable to act in very limited spaces, therefore the boring machine with which it is associated can be used substantially under any operating conditions. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     These and other characteristics of the invention will be clear from the following description of some preferred forms of embodiment, given as a non-restrictive example, with reference to the attached drawings wherein: 
     FIG. 1 is a three-dimensional view of the automatic loader for drill rods according to the invention; 
     FIGS. 2,  3  and  4  are schematic views from above of the automatic loader according to the invention in three different working steps; 
     FIG. 5 is a side view of a variant of the movement device of the automatic loader according to the invention; 
     FIG. 6 is a part sectional view of the movement device taken along line VI—VI of FIG. 5; 
     FIG. 7 is a partial side elevational view of the movement device as seen from line VII—VII of FIG. 5; 
     FIG. 8 is a sectional view of the movement device taken along line VIII—VIII of FIG. 5; and 
     FIG. 9 is a sectional view of the movement device taken along line IX—IX of FIG.  5 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     With reference to the attached drawings, an automatic loader  10  for drill rods  11  is laterally associated with a guide and drive assembly  12  of a boring machine. 
     The automatic loader  10  comprises a store  13  to contain the drill rods  11  and a movement device  14  able to pick up each drill rod  11  individually from the store  13  to position it on the guide and drive assembly  12  by means of which it is subsequently made to rotate in order to drill the ground. 
     The store  13  is solidly associated with the guide and drive assembly  12  by means of two brackets  15 , shown only in FIG. 1 for reasons of greater clarity, and comprises two disks  16 , parallel to each other, able to contain the drill rods  11  above and below. 
     The disks  16  are mounted on a shaft  17  able to be made to rotate selectively by means of an appropriate drive member  18 , for example consisting of a ratchet gear device commanded by a hydraulic cylinder or by a motion reducer of a conventional type. 
     On the shaft  17 , in an intermediate position between the disks  16  and parallel thereto, there are also two circular racks  19  provided on the perimeter with a plurality of hollows  20  arranged radially and able to keep the drill rods  11  positioned. 
     In a preferential embodiment, the two disks  16  can be positioned at a variable distance to adapt to the length of the different drill rods  11 , while the circular racks  19  are interchangeable according to the diameter of the rods  11 . 
     According to a variant, diameter reduction elements, not shown in the drawings, are able to be mounted, interposed between the circular racks  19  and the rods  11 , in correspondence with the hollows  20 . 
     With this solution it is not necessary to replace the circular racks  19  when the diameter of the drill rods  11  varies. 
     According to another variant, the circular racks  19  are provided, in correspondence with the hollows  20 , with retaining elements, not shown in the drawings, which can be selectively activated to keep the drill rods  11  in position. 
     The movement device  14  is also attached, by means of a relative profile  21 , to the guide and drive assembly  12 , in an intermediate position between the latter and the store  13 . 
     The movement device  14  comprises two oscillating arms  22 , of which only one can be seen in FIGS. 2-4, transverse with respect to the longitudinal axis of the guide and drive assembly  12 ; the oscillating arms  22  are pivoted on respective supports  23  attached to the profile  21  in correspondence with one end, and associated with a gripper member  24  at the other end. 
     A stationary arm  25  is also associated with the profile  21  at an intermediate position between the two supports  23 ; a first rod  27  of a double actuator  26  is constrained rotatably to the free end of said stationary arm  25 . 
     The second rod  28  of the double actuator  26  is pivoted on a collar  29  solidly associated with a cross-piece  30  which connects the two oscillating arms  22 . 
     By activating the double actuator  26 , the oscillating arms  22  are therefore able to be moved from a first position in proximity with the store  13  (FIG. 3) to a second position cooperating with the guide and drive assembly  12  (FIG.  4 ). 
     The gripper member  24  is constrained to the oscillating arms  22  by means of a pin  32  around the axis of which it is able to rotate selectively from a position facing the store  13  (FIGS. 2 and 3) to a position facing the guide and drive assembly  12  (FIGS.  1  and  4 ). 
     To be more exact, in the embodiment shown in FIGS. 2-4, a pinion  33  is keyed onto the pin  32  and a circular toothed sector  34 , made on a shaped plate  35  pivoted on one of the oscillating arms  22 , is engaged on the pinion  33 . 
     The rod  37  of an actuator  36  pivoted on a connection element  38  associated with said oscillating arm  22  is rotatably constrained to the shaped plate  35 . 
     Activating the actuator  36  causes the shaped plate  35  to rotate and therefore also the circular toothed sector  34  which, being engaged on the pinion  33 , transmits the rotation to the gripper member  24 . 
     In the embodiment shown here, the gripper member  24  comprises two pairs of jaws  31 , of which a single pair is visible in FIGS. 2-4, mounted on the pin  32 . 
     The jaws  31  of the gripper member  24  are connected in twos by a pair of transverse pins  40  with which an actuator  39  is associated in correspondence with the ends. 
     Activating the actuator  39  causes the two pairs of jaws  31  to rotate simultaneously with respect to the pin  32  and thus causes the gripper member  24  to open or close. 
     In this case, moreover, each jaw  31  has a pair of anti-slip inserts  41  able to improve the gripping conditions of the gripper member  24  on the drill rods  11 . 
     With reference to FIGS. 2-4, we shall now describe how the automatic loader  10  according to the invention works. 
     The movement device  14 , initially in the inactive position with the gripper member  24  open (FIG.  2 ), is brought near the store  13  by making the oscillating arms  22  rotate by retracting the rod  27  of the double actuator  26 . 
     In this position the gripper member  24  is in correspondence with a drill rod  11  and is closed by extending the rod  42  of the actuator  39 , causing the drill rod  11  to be gripped by the jaws  31  (FIG.  3 ). 
     Subsequently the rod  37  of the actuator  36  is extended to cause the shaped plate  35  to rotate and then, due to the effect of the coupling of the circular toothed sector  34  and the pinion  33 , it causes the gripper member  24  to rotate which directs the drill rod  11  towards the guide and drive assembly  12 . 
     By means of extending the two rods  27  and  28  of the double actuator  26 , the oscillating arms  22  are then made to rotate, arranging the drill rod  11  in the relative seating on the guide and drive assembly  12  (FIG.  4 ). 
     At the same time, the shaft  17  of the store  13  is made to rotate by the member  18  to arrange a new drill rod  11  in a position accessible for the movement device  14 . 
     By means of retracting the rod  42  of the actuator  39 , the drill rod  11  arranged on the guide and drive assembly  12  is then released and the movement device  14  is moved towards the store  13  to allow drilling operations to start and at the same time to pick up the new drill rod  11 . 
     When the new drill rod  11  has been picked up, the movement device  14  moves substantially to the position shown in FIG. 2, but with the gripper member  24  facing towards the guide and drive assembly  12  waiting for the first drilling step to be completed. 
     In this way, when at the end of the drilling step the guide and drive assembly  12  is free, the new drill rod  11  is quickly positioned simply by rotating the oscillating arms  22 . 
     The cycle to load the drill rods  11  then restarts in the manner described until the specified drilling depth is reached. 
     FIGS. 5-9 show a different embodiment of the movement device  14 . 
     This movement device  14  is provided with a different system to rotate the gripper member  24  which comprises an actuator  43  constrained at one end to the connection element  38  (FIG. 6) and at the other end to a lever assembly  50  (FIG. 7) associated with the gripper member  24 . 
     To be more exact, the actuator  43  is connected at an intermediate point of a first lever  44  of said assembly  50 , which pivots on a pin  45  mounted on one of the oscillating arms  22 . 
     The first lever  44  is connected by means of a pin  46  to a second lever  47 . 
     The second lever  47  is connected to a jaw  31  by means of a pin  48  with which a third lever  49  is also associated, pivoting on a pin  51  coaxial with the pin  32  (FIG.  7 ). 
     When the rod  52  of the actuator  43  is in its extracted condition, the gripper member  24  is facing towards the left, that is, towards the guide and drive assembly  12  (visible in FIGS.  2 - 4 ). 
     Activating the actuator  43  in the opposite direction, with the rod  52  retracted, causes the coordinated rotation in a clock-wise direction of the first lever  44  with respect to the pin  45 , the second lever  47  with respect to the pin  46  and the third lever  49  with respect to the pin  51 . 
     Accordingly, by means of the pin  48 , the whole gripper member  24  is made to rotate with respect to the pin  32  to be turned toward the store  13 , that is, towards the right in FIG.  7 . 
     The movement device  14  also comprises, in a position adjacent to the two pairs of jaws  31 , two relative alignment and centering assemblies  53 , keyed onto the pin  32  (FIG.  9 ). 
     Each alignment and centering assembly  53  comprises a supporting plate  54  provided at the front part with an abutment shoulder  57 ; at the sides of said plate  54  two elastic bars  55  are attached cantilevered. 
     The elastic bars  55  are arranged symmetrical with respect to the median longitudinal plane “X” of the gripper member  24  and are orthogonal with respect to the abutment shoulder  57 . 
     The elastic bars  55  are also provided with pads  56  at the end, advantageously made of anti-wear and anti-friction material, able to cooperate with the outer surface of the drill rods  11  together with the abutment profile  57 . 
     The alignment and centering assemblies  53  encourage the correct positioning of the gripper member  24  when the drill rod  11  is picked up. 
     To be more exact, when the gripper member  24 , with its jaws  31  open, approaches the drill rod  11  to be picked up, the elastic bars  55  move to the sides of the rod  11 , opening slightly to allow the latter to be positioned between them. 
     Subsequently, the approaching gripper member  24  causes the abutment shoulder  57  to rest on the rod  11 ; in this condition the rod  11  is closed between the elastic bars  55  in the centered position with respect to the median longitudinal plane “X” of the gripper member  24 . 
     The alignment and centering assemblies  53  are particularly advantageous also when the gripper member  24  has to release the drill rod  11  into the appropriate seating of the guide and drive assembly  12 . 
     During this step, in fact, when the jaws  31  are opened, the elastic bars  55  keep the rod  11  in an aligned position and at the same time, due to the presence of the pads  56 , allow the rod  11  to slide axially to be positioned on the guide and drive assembly  12 . 
     In the movement device  14  shown in FIGS. 5-9, moreover, each pair of jaws  31  is associated with a balancing mechanism  60  (FIG. 8) which makes possible for them to open and close symmetrically with respect to the median longitudinal plane “X” and therefore substantially with respect to the alignment and centering assembly  53  and the drill rod  11  to be picked up. 
     The balancing mechanism  60  comprises a pair of levers  58 , each one pivoted on a relative jaw  31  and connected to a common central pin  61 . 
     The central pin  61  can slide in an eyelet  62  arranged on the median longitudinal plane “X” and made on a plate  59  keyed onto the pin  32  which rotates the gripper member  24 . 
     During the opening-closing of the jaws  31 , the levers  58  rotate, making the central pin  61  slide inside the eyelet  62 ; the movement of the central pin  61  causes a coordinated and symmetrical rotation of the levers  58  and therefore the jaws  31  are symmetrically arranged with respect to the median longitudinal plane “X” and the axis of the alignment and centering assembly  53 . 
     In this way the rod  11  is clamped more securely by the gripper member  24 , to compensate for any possible play between the two. 
     It is obvious however that modifications and/or additions can be made to the automatic loader  10  as described heretofore, but these shall remain within the field and scope of the invention. 
     For example, the movement device  14  can comprise a single oscillating arm  22  and/or a single pair of jaws  31 , or the system to rotate the gripper member  24  may be of a different type. 
     Moreover, the store  13  can house a different number of drill rods  11 , also of a different diameter. 
     Furthermore, one of the two disks  16  can be of the stationary type, as it is sufficient that only one of them be movable in order to vary the configuration of the store  13  according to the length of the drill rods  11 . 
     It is also obvious that, although the invention has been described with reference to specific examples, a skilled person shall certainly be able to achieve many other equivalent forms of automatic loader for drill rods, all of which shall come within the field and scope of the invention.