Abstract:
A device for abrading a wooden barrel ( 13 ) includes a robot having elements ( 11, 17, 23 ) for loading a barrel ( 13 ), elements ( 29   a   , 29   b   , 33   a   , 33   b ) for gripping and rotating the barrel ( 13 ) around the axis thereof, elements ( 43   a   , 43   b ) for extracting and re-positioning the two bilge hoops of the barrel, elements ( 53 ) for abrading the barrel, and elements ( 69 ) for removing the barrel ( 13 ).

Description:
BACKGROUND OF THE INVENTION 
   1. Field of the Invention 
   The present invention relates to a device and a method for abrading, i.e. sanding, a wooden barrel. 
   2. Description of the Related Art 
   Traditionally, in barrel works, wooden barrels are sanded entirely manually: an operative loads the barrel onto a lathe, removes a first bilge hoop (a metal ring situated in the largest diameter region, known as the “bilge”) with a hammer and a drift, sands a first half of the barrel with a belt sander, replaces the first bilge hoop, removes the second bilge hoop, sands the second half of the barrel, replaces the second bilge hoop, and finally unloads the barrel from the lathe. 
   Apart from the fact that these operations are physically very tiring, the operative must work in a very dusty atmosphere. 
   Moreover, it takes a relatively long time to sand a barrel using the traditional technique. 
   An object of the present invention is to provide a device and a method that overcome these drawbacks. 
   SUMMARY OF THE INVENTION 
   That object of the invention is achieved with a device for sanding a wooden barrel, characterized in that it consists of a robot comprising:
         means for loading said barrel,   means for gripping and rotating said barrel around the axis thereof,   means for removing and replacing the two bilge hoops of said barrel,   means for sanding said barrel, and   means for removing said barrel.       

   Clearly, the device of the invention robotizes tasks that were previously difficult and lengthy, and thereby achieves the required improvement. 
   According to other features of the device of the invention:
     said gripping and rotating means comprise two mobile headstocks moving symmetrically and each including extendable clamping jaws,   said hoop removing and replacing means comprise a plurality of arms mounted to be mobile between an open position in which they are moved away from said barrel and a closed position in which they are able to grip one of said bilge hoops and to slide along the axis of said barrel,   said arms are mounted on a carriage adapted to slide between a first position in which said arms face one of said bilge hoops and a second position in which said arms face the other of said bilge hoops,   said arms comprise clamping shoes conformed to be applied to either of said bilge hoops interchangeably,   said device comprises means for preventing said arms from gripping each of said bilge hoops too tightly,   there are four arms,   said sanding means comprise a sanding head including a belt sander,   said sanding head is mounted so that it is able to slide along the axis of said barrel,   said device comprises means for varying the distance of said sanding head from the axis of said barrel,   said distance varying means comprise a deformable parallelogram,   said device comprises means for varying the inclination of said sanding head to the axis of said barrel,   said device comprises means for adjusting the pressure exerted on said barrel by said sanding head,   said device comprises a safety enclosure with an entry airlock and an exit airlock for said barrel,   said device comprises means for sequencing the passage of said barrel into said entry airlock,   said device comprises means for identifying the position of the bunghole of said barrel,   said device comprises means for immobilizing and lifting said barrel.   

   The method of the invention, applied to the above device, is characterized in that it comprises the steps of:
     a) placing said barrel between said gripping and rotating means,   b) gripping said barrel with said gripping and rotating means,   c) removing one of said bilge hoops on one half of said barrel with said hoop removing and replacing means,   d) rotating said barrel with said gripping and rotating means,   e) sanding said half barrel with said sanding means,   f) stopping the rotation of said barrel,   g) replacing said bilge hoop with said hoop removing and replacing means,   h) repeating steps c) to g) for the other bilge hoop and the other half of said barrel, and   i) releasing said barrel from said gripping and rotating means.   

   According to other features of the method of the invention:
     for executing said step e), said sanding head is moved in the direction of the axis of said barrel,   between said steps b) and c), the position of said bunghole is identified in order to position said barrel so that said hoop removing and replacing means do not interfere with riveted areas of said bilge hoops,   to execute said step c), said barrel is rotated so that it occupies a plurality of successive positions and, in each of said positions, removal forces are exerted on said bilge hoop with said hoop removing and replacing means.   

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other features and advantages of the invention will become apparent in the light of the following description and on examining the appended drawings, in which: 
       FIG. 1  is a front view of the device of the invention, and 
       FIG. 2  is a side view of the device of the invention. 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  of the appended drawings shows that the device of the invention comprises a safety enclosure  1  that is preferably soundproofed and comprises an entry airlock  3 , a main chamber  4  and an exit airlock  5 . 
   Doors P 1  and P 2  separate the entry airlock  3  from the main chamber  4  and the main chamber from the exit airlock  5 , respectively. 
   A pair of parallel rails with a slight inclination known as a track  7  terminates in the entry airlock  3  and conveys thereto a barrel  9  to be processed. 
   A sequencer device  11  immobilizes the barrel  9  to be processed in the entry airlock  3  until the processing of the preceding barrel  13  has been completed. 
   The sequencer device  11  may comprise rollers  15   a ,  15   b  rotatably mounted at the two ends of a deformable parallelogram  17  mounted pendulum-fashion on a support  19  and actuated by a cylinder  21 . 
   A track  23  links the entry airlock  3  to the main chamber  4 . 
   The main chamber  4  contains means for immobilizing and lifting the barrel  13  before it is processed. 
   As is apparent in  FIGS. 1 and 2 , those means may comprise buffers  25   a ,  25   b  that are raised by a lead screw  27  until they come into contact with and then lift the barrel  13 . 
   The main chamber  4  further contains means for gripping the barrel  13  and rotating it about its axis A. 
   As may be seen in  FIGS. 1 and 2 , those means may comprise two motorized mobile headstocks  29   a ,  29   b  each including a chuck  31   a ,  31   b  with extendable jaws  33   a ,  33   b.    
   The term “extendable” means that the jaws  33   a ,  33   b  can be moved in the direction of the axis A of the barrel  13  by pneumatic cylinders  35   a ,  35   b  visible in  FIG. 2 . 
   A high-power electric motor  37  is adapted to drive rotation of the chuck  31   b.    
   The main chamber  4  further contains means for removing and replacing the two bilge hoops  39   a ,  39   b  of the barrel  13 . 
   As can be seen in  FIG. 2 , the bilge hoops are the metal hoops that are situated in the bulging portion of the barrel  13 , known as the “bilge”, one on each either side of the bunghole  41 . 
   The hoop removing and replacing means comprise a plurality of arms, preferably four arms  43   a  to  43   d  as shown in  FIG. 1 , mounted on a carriage  45  to pivot about axes parallel to the axis A of the barrel. 
   These arms are therefore mobile between an open position, represented in thicker line in  FIG. 1 , in which they are moved away from the bilge hoops  39   a ,  39   b , and a closed position, represented in thinner line in  FIG. 1 , in which they are able to grip the bilge hoops. 
   The arms  43   a  to  43   d  are actuated in these two positions by cylinders  47   a  to  47   d  disposed between the arms and the carriage  45 . 
   As can be seen in  FIG. 1 , the ends of the arms  43   a  to  43   d  carry clamping shoes  49   a  to  49   d  mounted to rotate relative to the arms about axes parallel to the axis A of the barrel  13 . 
   The clamping shoes are conformed so that they are able to cooperate firmly with either of the bilge hoops  39   a ,  39   b.    
   Pressure sensors known in the art (not shown) are preferably provided so that the arms  43   a  to  43   d  do not apply too high or too low a pressure to the bilge hoops  39   a ,  39   b  after their removal. 
   The carriage  45  is mounted to be slid along the axis A of the barrel  13  by appropriate conventional means, for example rails  51   a  and  51   b  and a lead screw  52  extending along the axis A. 
   The main chamber  4  further contains means for sanding the barrel  13 . 
   As is apparent in  FIGS. 1 and 2 , those means comprise a sanding head  53  including a sanding belt  55  driven by an electric motor  57  in a direction substantially transverse to the axis A of the barrel  13 . 
   The sanding head is suspended from a frame  60  mounted to be slid along the axis A of the barrel  13  by appropriate conventional means, for example rails  59   a  and  59   b  and a lead screw  61  extending along the axis A. 
   Means are provided for varying the distance of the sanding head  53  from the axis A of the barrel  13 . 
   As can be seen in  FIG. 1 , those means may comprise two links  63   a ,  63   b  linking the sanding head  53  to the frame  60  and substantially defining a deformable parallelogram. 
   Means are also provided for varying the inclination of the sanding head  53  to the axis A of the barrel  13 . 
   As can be seen in  FIG. 2 , those means comprise an arm  65  for rotating the head  53  relative to the frame  60  about a substantially horizontal axis perpendicular to the axis A of the barrel  13  and a cylinder  67  for actuating the arm  65  disposed between the head  53  and the frame  60 . 
   Means known in the art and not shown ensure that the sanding belt  55  applies a constant pressure to the barrel  13 . 
   As can be seen in  FIG. 1 , a track  69  connects the main chamber  4  to the exit airlock  5 . 
   Means known in the art are also provided for marking the position of the bunghole  41 . Those means may comprise a photoelectric cell, for example (not shown). 
   All of the moving parts of the device of the invention are controlled by an electronic circuit connected to a man/machine interface (not shown) enabling an operative to fix set points associated with each type of barrel to be processed. 
   The operation and the advantages of the device of the invention are clear from the foregoing description. 
   The barrel to be processed arrives in the entry airlock  3 , rolling along the track  7 , and reaches the position  9  represented in  FIG. 1 . 
   The sequencer  11 , which is in the position represented in  FIG. 1  for as long as the preceding barrel  13  is being sanded in the chamber  4 , immobilizes the barrel  9  inside the airlock  3 . 
   When the sanding of the preceding barrel  13  has been finished and that barrel has left the chamber  4 , the cylinder  21  pivots the sequencer  11  so that the roller  15   a  is in the raised position and the roller  15   b  is in the lowered position. 
   The door P 1  is then opened and the barrel  9  rolls along the track  23  into the chamber  4 , until it reaches the position  13  seen in  FIG. 1 . The door P 1  is then closed. 
   Driven by the lead screw  53 , the buffers  25   a ,  25   b  come into contact with the barrel  13  and then lift it until it reaches a position in which its axis A is substantially aligned with the rotation axes of the headstocks  29   a  and  29   b  (see  FIG. 2 ). 
   The pneumatic cylinders  35   a ,  35   b  then place the jaws  33   a ,  33   b  of the chucks  31   a ,  31   b  against the two ends of the barrel  13  to hold the barrel firmly. 
   The electric motor  37  rotates the barrel  13  so that the bunghole  41  moves in front of the photoelectric cell so that it may be identified. 
   Once this identification has been effected, the barrel  13  continues to turn to a position in which it is certain that the shoes  49   a  to  49   d  will be pressed onto areas of the bilge hoops  39   a ,  39   b  with no rivets. 
   In other words, identifying the position of the bunghole  41  indexes the angular position of the barrel  13  in order to optimize the gripping of the bilge hoops  39   a ,  39   b  by the arms  43   a  to  43   d.    
   The carriage  45  then slides on the rails  51   a ,  51   b  until the arms  49   a  to  49   d  are in line with the bilge hoop  39   a.    
   The cylinders  47   a  to  47   d  are then actuated so that the shoes  49   a  to  49   d  are pressed onto the bilge hoop  39   a  and grip it. 
   The carriage  45  then slides to remove the bilge hoop and then pass it over the head of the barrel  13 . 
   Once it has been extracted, the gripping force applied to the bilge hoop  39   a  by the arms  43   a  to  43   d  is controlled so that the arms do not crush the hoop. 
   Note that if removing a hoop proves difficult, removing it in several stages may be envisaged, turning the barrel through a certain angle (for example 45°) between attempts. 
   The barrel  13  is then rotated continuously by the electric motor  37 . 
   The deformable parallelogram  63   a ,  63   b  then lowers the sanding head  53  until the sanding belt  55  comes into contact with the head of the barrel  13 . 
   The motor  57  is then started, which drives the sanding belt  55 . 
   While the barrel  13  is turning about its axis, the sanding head  53  slides on the rails  59   a ,  59   b.    
   The relative speeds of rotation of the barrel  13 , on the one hand, and of translation of the head  53 , on the other hand, are adapted so that a single excursion of the head  53  between the end and the bilge of the barrel  13  is sufficient to sand half of the barrel. 
   Once this sanding has been effected, the bilge hoop  39   a  is replaced by a sequence of operations in the reverse order to that described above: the carriage  45  slides to reposition the hoop  39   a  on the bilge of the barrel  13 , after which the arms  43   a  to  43   d  are moved apart to release the hoop. 
   All of the steps described above are then repeated to remove/replace the other bilge hoop  39   b  and sand the second half of the barrel  13 . 
   It will be noted that while the sanding head  53  is advancing, its inclination to the axis A of the barrel is adjusted by the cylinder  67  operating on the arm  65 . 
   Thus the sanding belt  55  can at all times be tangential to the generatrices of the barrel  13 . 
   For example,  FIG. 2  shows two different inclinations of the belt  55 , corresponding to positions in which the belt is in the regions of the heads  55   a ,  55   b  or the bilge  55  of the barrel  13 . 
   As is clear in the light of the foregoing description, only one bilge hoop is removed at a time, which means that the staves forming the barrel are held together while the corresponding half of the barrel is sanded, which prevents sawdust penetrating to the interior of the barrel. 
   Once the whole of the barrel has been sanded, the sanding head  53  is raised by the links  63   a ,  63   b , rotation of the barrel is stopped, the jaws  33   a ,  33   b  are opened, the barrel is lowered onto the track  69 , the door P 2  is opened, and the barrel is evacuated into the exit airlock  5 . 
   The next barrel can then be sanded in its turn. 
   As is clear in the light of the foregoing description, the device of the invention is able to sand wooden barrels entirely automatically, so that the irksome and lengthy manual operations of the prior art can be dispensed with. 
   For example, the device of the invention is able to sand a 228-liter barrel in less than two minutes. 
   Of course, the present invention is not limited to the embodiment described and shown, which is provided by way of illustrative and nonlimiting example.