Abstract:
The present invention relates to a device used to mechanically enlarge the base de caissons, so as to form a semi-spherical cavity in the base de the caisson formed, in which said device includes a socket in the upper extremity thereof for the engine shaft, a guide ring, a soil excavating mechanism and a recipient for collecting the excavated soil.

Description:
TECHNICAL FIELD 
       [0001]    This patent of invention application relates to a device to be used in mechanically enlarge of caisson bases, so that form a semi-spherical cavity at the base of caisson performed. 
         [0002]    Currently, every soil excavating process for carrying out of base for caissons é performed manually, consisting of carrying out the same with a operator going down in the shank of caisson for enlarging the base, which process impose risks to the executor, incurring the possibility of soil landslip. 
         [0003]    In this patent of invention application, the developed process has the purpose to remove the human figure of the process, avoiding burial risks and speeding up the base enlarging process, which is efficient in terms of reduction of execution time in the order of 80% or more. 
         [0004]    Some features of purpose of invention are:
       possibility of change in knives, which allows a opening of bases with different diameters;   creation of a collector system facilitating the removal of excavated soil, besides take the easy of coupling in consideration.       
 
       SUMMARY DESCRIPTION OF INVENTION 
       [0007]    The present invention relates to a device to be used in mechanically enlarge of caisson bases. 
         [0008]    Device for enlarging caisson bases comprises:
       an engine shaft;   a socket of engine shaft;   a fixation pin of engine shaft;   a moveable column;   a guide ring bound to moveable column;   a rotary joint, a stationary column;   two side arms and two knives fixed to arms, which are part of soil excavating mechanism;   a collector vessel of excavated soil bound to stationary column; and   pivotable caps at vessel.       
 
         [0018]    The device is a mechanism comprising, at upper extremity, the socket of engine shaft of machine carrying out the mechanical excavating of caisson (the fixation of shaft in socket is made through cylindrical pin), being, at the side arms, the knives carrying out the enlarging and, at lower extremity, a collector vessel of excavated soil. 
         [0019]    The engine shaft rotates and presses the device against the bottom of orifice. The side arms of device open and the knives perform the excavation of soil, which is lodge at collector vessel, as the excavation proceeds. 
         [0020]    The collector vessel, at the base of mechanism, is bound to its, through rotary joint, so that, while the mechanism rotates, the collector vessel could not rotate. 
         [0021]    After the end of operation, a collector pan can already rotate, removing the soil from the bottom of caisson which is irregular due to excavation process of shank, providing a compact surface at the base of same. 
         [0022]    To better understanding, the following schematic figures of particular embodiments of invention will be shown, the dimensions and ratios of which are not real necessarily, because the figures has the only purpose for didactically show the preferred applications, the protection scope of which is determined by the scope of appended claims. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0023]    This invention will be better understood by means of figures, which illustrate schematically the following: 
           [0024]    FIG.  1 —perspective view of device in general feature; 
           [0025]    FIG.  2 —front view of device during the performance of enlarging of caisson base; 
           [0026]    FIG.  3 —view of device at initial position, about to initiate the enlarging of caisson base; 
           [0027]    FIG.  4 —view of device at final position of enlarging operation; 
           [0028]    FIG.  5 —view of device already out of caisson, with pivotable caps at position for eliminating excavated soil; 
           [0029]    FIG.  6 —view of shank of accomplished caisson ( 6   a ) and view of caisson base enlarged by device ( 6   b ); 
           [0030]      FIG. 7  —view of stationary and moveable columns, separated by rotary joint, in details; and 
           [0031]    FIG.  8 —schematic view of fixation of knife in the side arm. 
       
    
    
     DETAILED DESCRIPTION OF INVENTION 
       [0032]    According to  FIG. 1 , it is possible to note the general feature of device for enlarging caissons, said device comprising, at upper extremity thereof, a socket ( 11 ) of engine shaft ( 1 ), a guide ring ( 2 ), a soil excavating mechanism ( 3 ), and a collector vessel for excavated soil ( 4 ). 
         [0033]    Said soil excavating mechanism ( 3 ) and collector vessel of excavated soil ( 4 ) has cylindrical shape, which fits to diameter of caisson to be enlarged. 
         [0034]      FIG. 2  shows the device in details, during the performance phase of enlarging a caisson base, wherein said device comprises, at upper extremity thereof, the socket ( 11 ) of engine shaft ( 1 ) of machine carrying out the mechanical excavating of caisson, wherein a fixation of shaft ( 1 ) in the socket ( 11 ) is made through a cylindrical fixation pin ( 12 ), said device comprises, at side arms ( 6 ) thereof, knives ( 7 ) which perform the enlarging of caisson base, and said device further comprises a collector vessel ( 4 ) of excavated soil at lower extremity thereof. 
         [0035]    During the enlargement performance, engine shaft ( 1 ) rotates and presses the device against the bottom of caisson, thus, side arms ( 6 ) open and knives ( 7 ), fixed to arms ( 6 ), perform excavation of soil, which will be lodge in the collector vessel ( 4 ). Said collector vessel ( 4 ) is bound to said mechanism ( 3 ), at base thereof, through a rotary joint ( 8 ), such that, while mechanism ( 3 ) rotates, the vessel ( 4 ) could not rotate. 
         [0036]    Said side arms ( 6 ) are fixed in the excavating mechanism ( 3 ) through horizontal bars ( 62 ) and pivotable bars ( 61 ), moving in accordance with motion of moveable column ( 5 ), as said moveable column ( 5 ) is pressed against the caisson, thus allowing the arms ( 6 ) to leave of initial position thereof, and moving to the final position of enlarging process. Said bars ( 61 ,  62 ) and arms ( 6 ) are hinged through pins ( 63 ). 
         [0037]      FIGS. 3 and 4  show, respectively, device at the initial position, about to initiate the enlarging operation of caisson base, and the device at the final position of operation, wherein the soil excavated by knives ( 7 ) is lodged in the collector vessel ( 4 ). Device is shown at  FIG. 5 , already out of caisson after operation, with pivotable caps ( 41 ) at position for eliminating excavated soil, arranged at lower portion of collector vessel ( 4 ). Said pivotable caps ( 41 ) have a semi-circular shape, matching with collector vessel ( 4 ). 
         [0038]      FIGS. 6   a  and  6   b  show the shank of accomplished caisson, before and after the base enlarging by said device, respectively. 
         [0039]    In accordance with  FIG. 7 , it can be seen the columns, called stationary ( 9 ) and moveable ( 5 ), separated by rotary joint ( 8 ) of device for enlarging. 
         [0040]    Said stationary ( 9 ) and moveable ( 5 ) columns have cylindrical shape, and further, said moveable column ( 5 ), according to motion thereof, works at the device like a shaft. 
         [0041]    At the beginning of enlarging operation, pin ( 81 ) crosses the lock ( 82 ), and lateral portion ( 85 ) of rotary joint ( 8 ), such that two columns stand alone. This allows the rotate of collector pan ( 4 ), removing the soil from the bottom of caisson, which is irregular due to excavation process of shank, and providing a compact surface at the base of caisson. 
         [0042]    A lower portion ( 84 ) is a stand-alone stationary column ( 9 ), and together with upper portion ( 83 ), through bolt ( 87 ), they make a coupling of rotary joint ( 8 ), which allows motion at the same longitudinal axis of engine shaft ( 1 ), and moveable column ( 5 ) with the stationary column ( 9 ). This alignment is obtained in operation both with and without the lock pin ( 81 ). 
         [0043]    Rotary joint ( 8 ) further comprises abutment joints ( 86 ) disc-shaped, to eliminate the friction between metallic parts in the excavation operation of soil, wherein, at this moment, only the moveable column ( 5 ) rotates. 
         [0044]    At following step, lock pin ( 81 ) is removed, and only the moveable column ( 5 ) rotates, causing the knives ( 7 ) starts the soil removal process. 
         [0045]    Said knives ( 7 ) are fixed to side arms ( 6 ) through three bolts ( 64 ), as shown at  FIG. 8 , providing a risk-proof fixation. 
         [0046]    In addition, device allows utilization of knives with different sizes, so as to provide different diameters of base for the same diameter as the shank of caisson. Said knives ( 7 ) have an L-shape, and at upper portions thereof, a portion of knife ( 71 ) is tilted, so as remove the soil easier. 
         [0047]    The scope of this patent of invention, therefore, should not be limited to illustrated applications, but, instead, only to terms defined at claims and equivalents thereof.