Abstract:
A gripper for capturing and transporting a food product. In one implementation the gripper has first and second arms having first end portions that cooperate with each other to capture the food product. In a first pivot position the first end portion of the first arm is positioned to cooperate with the first end portion of the second arm to capture the food product, whereas in a second pivot position the first end portion of the first arm is positioned not to cooperate with the first end portion of the second arm. The gripper has an expandable fluid chamber that in an expanded state acts on a portion of the first arm to cause the first arm to assume the first pivot position.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application relates to and claims priority to European Patent application No. 11382146.6, filed May 12, 2011. 
     FIELD 
     This invention relates to grippers for capturing and transporting foodstuffs, and in particular to grippers for capturing and transporting foodstuffs, adapted for use in packaging processes. 
     BACKGROUND 
     Grippers for capturing and transporting products of different characteristics are well known from prior art, said products including foodstuffs, for example. 
     These types of grippers comprise a plurality of arms, which open and/or close like jaws to capture or release a product. Each arm comprises a main end and when the gripper closes to capture a product both main ends move towards each other, trapping the product between them. Different means for causing the opening and closing of the arms are also known. 
     Document US 20040207222 A1 discloses a gripper with two arms, both arms pivoting in relation to a corresponding axis of rotation to open or close the gripper, the rotation being caused by the rectilinear movement of an actuating piece. 
     Document U.S. Pat. No. 6,666,489 B2 discloses a gripper with two arms in which one of the arms pivots in relation to an axis of rotation so that the gripper captures or releases a product, the other arm remaining in a fixed position. The pivoting of the arm is performed by means of a cylinder, through the movement of its rod. 
     SUMMARY 
     It is an object of this invention to provide a gripper for capturing and transporting foodstuffs, as described in the claims. 
     The gripper for capturing and transporting foodstuffs of the invention comprises a plurality of arms. Each arm comprises a main end, and all the main ends cooperate with each other to capture a product in the manner of a jaw, at least one of the arms being adapted to pivot in relation to a corresponding point of rotation so that the main ends capture the product. 
     The pivoting for capturing or seizing the product is performed by means of a fluid that acts on the arm that is adapted to pivot. As a result, the pressure exerted on the product by the gripper can be regulated in a simple and efficient manner, thereby controlling the amount and/or the pressure of the fluid that acts on the arm, ensuring a correct seizure of the product that prevents its accidental release and an excessive seizure that may cause unwanted damage to the product. 
     These and other advantages and characteristics of the invention will be made evident in the light of the drawings and the detailed description thereof. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a perspective view of a first embodiment of the gripper of the invention. 
         FIG. 2  shows the gripper according to the embodiment of  FIG. 1 , without a cover and with an arm in an open position. 
         FIG. 3  shows the gripper according to the embodiment of  FIG. 1 , without a cover and with an arm in a closed position. 
         FIG. 4  shows a perspective view of a second embodiment of the gripper of the invention. 
         FIG. 5  shows the gripper according to the embodiment of  FIG. 4 , without a cover and with the arms in an open position. 
         FIG. 6  shows the gripper according to the embodiment of  FIG. 4 , without a cover and with the arms in a closed position. 
     
    
    
     DETAILED DESCRIPTION 
       FIGS. 1 to 4  show a first embodiment of the gripper  100  for capturing and transporting foodstuffs of the invention, which is designed to capture objects with a uniform shape such as sausages.  FIGS. 5 to 7  show a second embodiment of the gripper  100  for capturing and transporting foodstuffs of the invention, which is designed to capture objects with a non-uniform shape, such as chicken wings or breasts. 
     In both embodiments the gripper  100  comprises a plurality of arms  1  that cooperate with each other to capture the product in the manner of a jaw. Each arm  1  comprises a main end  10  and the product is captured between all the main ends  10  of the arms  1  of the gripper  100 , with all the main ends  10  cooperating with each other to capture a product. In order to perform the capture at least one of the arms  1  is adapted to pivot in relation to a point of rotation, causing the main end  10  of said arm  1  to move closer to the other main ends  10  of the different arms  1 , the product being captured or trapped between said arms  1 . 
     In both embodiments the gripper  100  comprises an actuator to cause, when the product is to be captured, a fluid to push a distal end  11  opposite to the main end  10  of the arm  1  (or the arms  1 ) that can pivot, thereby causing the arm  1  to pivot in relation to the point of rotation, the main ends  10  of the different arms  1  being brought closer to each other. 
     In both embodiments the gripper  100  comprises a support structure  3  to which the arms  1  are connected, and a chamber  4  disposed on the support structure  3  where the fluid that pushes the distal end  11  of any arm  1  that can pivot is introduced, the chamber  4  expanding when the fluid is introduced into its interior. Any arm  1  that can pivot is connected to a side of the support structure  3  with the possibility of pivoting, the point of connection between said arm  1  and the support structure  3  corresponding with the point of rotation. The main end  10  is beneath the support structure  3  whereas the distal end  11  is above the support structure  3 . As a result, the chamber  4  is in contact with the distal end  11 , and when, due to the introduction of the fluid, the chamber  4  expands, said chamber  4  pushes the distal end  11 , causing the corresponding arm  1  to pivot in relation to the point of rotation. 
     In both embodiments, the gripper  100  comprises an elastic assembly  8  to cause any arm  1  that has pivoted due to the fluid to return to its original position once said fluid has been removed from the chamber  4 , and to keep the arms  1  in their original position while there is no fluid in the chamber  4 , which can correspond to a rubber piece or equivalent member, for example. The elastic assembly  8  surrounds, at least partially, the chamber  4 , and the distal end  11  of any arm  1  that can pivot is disposed between the elastic assembly  8  and the chamber  4 . As a result, when a fluid is introduced into the chamber  4 , this expands and exerts a force against the distal end  11  that is greater than that exerted by the elastic assembly  8 , causing the arm  1  to pivot, whereas when the fluid is removed the elastic assembly  8  exerts a force in an opposite direction to recover their original shape, causing said arm  1  to pivot in the opposite direction, returning to its original position. 
     On the introduction of the fluid into the chamber  4  to cause the arms  1  to capture a product, when one of the arms  1  makes contact with the product the fluid is distributed in the interior of the chamber  4  so that when all the arms  1  make contact with the product they do so exerting the same pressure on said product, thereby resulting in a uniform and safe seizure of the product. 
     In the first embodiment, as the shape of the product to be captured is uniform, the necessary arms  1  can be disposed in a certain shape that depends on the product to be captured and it is not necessary for all the arms  1  to pivot, the gripper  100  being capable of comprising an arm  1  that can pivot. The arms  1  that cannot pivot are fixed to the support structure  3 .  FIG. 2  shows the first embodiment of the gripper  100  with said arm  1  in an open position where it has not pivoted, and  FIG. 3  shows the first embodiment of the gripper  100  with the arm  1  in a closed position where it has pivoted to capture a product. In addition, to help capture the product, the main end  10  of at least one of the arms  1  can comprise a suitable shape so that the product is held correctly by the arms  1 , a shape that depends on the product to be captured, said main end  10  thus comprising a surface of contact  10   a  greater than the rest of the main ends  10 , as shown in  FIG. 3 . In addition, the main end  10  of the arm  1  that can pivot can be flexible, so that it can be easily adapted to the shape of the product to be captured, thereby ensuring a correct seizure of the product. 
     In the first embodiment the gripper  100  preferably comprises a cover  5  shown in  FIGS. 2 and 3  that is attached to the support structure  3 , the chamber  4  being disposed and delimited between the support structure  3  and the cover  5 . In addition, either the cover  5 , on a surface that faces the support structure  3 , or the support structure  3 , on a surface that faces the cover  5 , can comprise a housing not shown in the figures, adapted to house the chamber  4 . Said cover  5  is also covered, preferably by a cover  101  shown in  FIG. 1 . 
     In the first embodiment, the cover  5  covers the chamber  4  both by the top part and by its outer perimeter, and comprises a window  51  through which the chamber  4  can expand. The distal end  11  of the arm  1  that can pivot faces the window  51 , so that the chamber  4  can push said distal end  11  causing the pivoting of the arm  1 . The elastic assembly  8  surrounds the perimeter of the cover  5 , surrounding the chamber  4  along the length of the window  51  of the cover  5  and covering in said length the distal end  11  of said arm  1 . 
     In the first embodiment, the chamber  4  comprises a valve or an equivalent member through which the fluid can be introduced into or removed from its interior, and the actuator comprises a pipe  7  through which the fluid reaches the valve so that it can be introduced into the chamber  4 . Preferably, the cover  5  comprises a through hole  50  that is passed through by the pipe  7  to reach the chamber  4 , although the through hole  50  can be in the support structure  3 . 
     In the second embodiment, as the product to be captured is not uniform, all the arms  1  of the gripper  100  can pivot in relation to the support structure  3 .  FIG. 4  shows the second embodiment of the gripper  100 , with the arms  1  in an open position where they do not capture a product, and  FIG. 5  shows the second embodiment of the gripper  100 , with the arms  1  in a closed position that is the position they adopt to capture a product. The chamber  4  comprises a substantially circular shape with a central space  40 , as shown in the  FIG. 5 , and the gripper  100  can comprise a support  102 , shown in  FIG. 6 , which is disposed in the central space  40  that defines and supports the chamber  4 , both the chamber  4  and the support  102  being capable of being covered by a cover  5 , the chamber  4  being disposed and delimited between the support structure  3  and the cover  5 . 
     In the second embodiment, the elastic assembly  8  covers the distal ends  11  of all the arms  1 , thereby surrounding the chamber  4 . The cover  5  covers the chamber  4  by its top part and its outer perimeter, acting as a cover, as shown in  FIG. 4 . 
     As in the first embodiment, in the second embodiment the chamber  4  can comprise a valve or an equivalent member through which the fluid is introduced into or removed from its interior, and the actuator comprises a pipe  7  through which the fluid reaches the valve so that it can be introduced into the chamber  4 . Preferably, the cover  5  comprises a through hole  50  that is passed through by the pipe  7  so that it can reach the chamber  4 , although the through hole  50  can be in the support structure  3 .