Patent Abstract:
An avocado processor extracts the pulp from the fruit. The avocados are heated, cooled, sliced in half, depitted, and squeezed all while continuously traveling along a conveyor path. The squeezing is handled by V-shaped finger assembly. Guides force the fingers to close as they move along the path.

Full Description:
FIELD OF THE INVENTION 
       [0001]    This invention relates in general to processing fruit, and in particular, to a method of processing avocados. 
       BACKGROUND OF THE INVENTION 
       [0002]    An avocado is an organic green colored tropical fruit that is roughly spherical or ellipsoid in shape. Avocados generally have a major axis length ranging from 2 to 4 inches long, contain a single hard seed in the center of the fruit, and have a wrinkled leathery outer skin or rind. When harvested ripe and processed within a few hours, the edible pulp of this fruit is firm and easy to remove. However, if the fruit is not ripe, the pulp is too hard to effectively remove from the fruit. If the fruit is over ripe, the pulp is too soft and mushy to effectively remove from the fruit. A variety of methods are employed to extract the pulp from the avocado, however many of these methods require extensive manual labor. 
         [0003]    For example, a laborer might hand wash, slice, and depit the avocados in a processing system. With this system, a great deal of manual labor and time is involved in processing the avocados. Furthermore, once the avocado has been sliced and depitted, more manual labor is required in removing the pulp from the avocado. While manual processing may be a successful method, this system of processing requires a large amount of physical labor and also involves a large amount of time associated with this labor 
       SUMMARY OF THE INVENTION 
       [0004]    In this invention, an automated system processes the avocados as they work their way along a continuous path. The avocados are preferably heated and cooled prior to squeezing in order to increase the ease with which the pulp is removed from the rind. Following the heating and cooling process, the avocados are conveyed along a path where they are sliced in half with a rotating blade. The avocado halves are then conveyed to a squeeze cell where they are depitted and squeezed as they continue along a desired path. As the avocado halves continue through the squeeze cell, a squeezing force is applied to the halves, causing the pulp to be removed from the rind. The pulp is collected and conveyed for further processing, as the rind is then disposed of. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a flow chart of the method for processing avocados as comprised by the invention. 
           [0006]      FIG. 2  is a schematic of the heating and cooling tanks with conveyor belts. 
           [0007]      FIG. 3  is an isometric view of the mesh conveyor belts employed in the heating and cooling tanks. 
           [0008]      FIG. 4A  is an end view of the feed conveyors leading to the slicer. 
           [0009]      FIG. 4B  is an isometric view of the feed conveyors leading to the slicer. 
           [0010]      FIG. 5  is a schematic side view of the feed conveyor as it passes through the slicing mechanism. 
           [0011]      FIG. 6  is a top view of the transition from the feed conveyor to a transfer conveyor leading to a squeeze cell. 
           [0012]      FIG. 7  is a side view of the squeeze cell with depitting stations. 
           [0013]      FIG. 8A  is a sectional view of a V-shaped clamp with guide tracks, with fingers in an open position, and taken along the line  8 A- 8 A of  FIG. 7 . 
           [0014]      FIG. 8B  is a sectional view of the V-shaped clamp with guide tracks, with fingers in a gripping position, and taken along the line  8 B- 8 B of  FIG. 7 . 
           [0015]      FIG. 8C  is a sectional view of the V-shaped clamp with guide tracks, with fingers in a near closed position, and taken along the line  8 C- 8 C of  FIG. 7 . 
           [0016]      FIG. 9A  is a sectional view of alternate embodiment of a clamp with guide tracks, with dual hinged fingers in an open position. 
           [0017]      FIG. 9B  is a sectional view of the clamp and guide tracks of  FIG. 9A , with the dual hinged fingers in a gripping position. 
           [0018]      FIG. 9C  is a sectional view of the clamp and guide tracks of  FIG. 9A , with the dual hinged fingers in a near closed position. 
           [0019]      FIG. 10A  is a sectional view of alternate embodiment of a clamp with guide tracks, with concave fingers in an open position. 
           [0020]      FIG. 10B  is a sectional view of the clamp and guide tracks of  FIG. 10A , with the concave fingers in a gripping position. 
           [0021]      FIG. 10C  is a sectional view of the clamp and guide tracks of  FIG. 10A , with the concave fingers in a near closed position. 
           [0022]      FIG. 11  is a schematic top view of the idle roller squeezing device. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0023]    Since avocados are an organic product, the size and shape are not within human control; therefore, it is the responsibility of other sorting systems to group like size fruit together and to reject damaged fruit prior to delivery to this process. 
         [0024]    Referring to  FIG. 1 , the method for processing avocados as comprised by this invention involves passing the avocados through the following: a heating and cooling station  21 , then a slicing station  23 , and finally, a depitting and squeezing station  25 . 
         [0025]    Referring to  FIG. 2 , the avocados are conveyed through a brusher  31 , which cleans the outer skin of the avocados using a combination of liquid spray and brushing. After the avocados leave brusher  31 , they are immersed and conveyed through a heated liquid tank  34  by means of mesh conveyor belts  33 . Preferably, the avocados are immersed in the heated liquid for thirty seconds. The avocados are then exposed to room temperature air  35  as they are transferred from the heated liquid tank  34  to the chilled liquid tank  36 . Preferably, the avocados are exposed to room temperature air for eight seconds. The avocados are then immersed, and conveyed through a chilled liquid tank  36  by means of mesh conveyor belts  33 . Preferably, the avocados are immersed in the chilled liquid for thirty seconds. The avocados are then exposed to room temperature air  37  as they are transferred from the chilled tank  36  to the chilled sanitizing liquid tank  38 . Preferably, the avocados are exposed to room temperature air for eight seconds. The avocados are then immersed, and conveyed through a chilled sanitizing liquid tank  38  by means of mesh conveyor belts  33 . Preferably, the avocados are immersed in the chilled sanitizing liquid for thirty seconds. Referring to  FIG. 3 , mesh conveyor belts  33  travel in the same direction, above and below the avocados. 
         [0026]    Referring to  FIGS. 4A and 4B , the avocados travel from the heating and cooling station to the slicing station on feeder conveyors  41 . The feeder conveyor is constructed of two independent parallel flat belt conveyors  41  that are opposing yet inclined to each other along their short axis, thereby forming a V-trough. The conveyors  41  are essentially mirror image in design and the two belts  41  run in the same direction. The angle of inclination between the flat belt conveyors  41  is adjustable. The avocados are loaded into the open space between the two conveyors  41  and rest on the bottom tangential surfaces. A small gap is maintained at the bottom of the conveyors  41  and is adjustable. The avocados continue along feeder conveyors  41  and through the slicing station. 
         [0027]    Referring to  FIGS. 4A and 5 , towards the end of feeder conveyors  41 , a rotating saw blade  51  is mounted to allow for vertical adjustment. The blade  51  passes through the gap at the bottom of conveyors  41 . Guided rollers  42  engage each side of the blade  51  in the gap to minimize deflection, and to ensure precision. Blade  51  is used to automatically cut through the avocado and its seed in order to produce two halves of roughly equal dimension. Ideally, the cut surface is vertical and along the long axis at the centerline of the avocados. As the avocados continue down the conveyors  41 , the saw blade  51  rotates in the same direction as the conveyors  41  in order to push the fruit further into the trough of conveyors  41  as the fruit passes through the blade  51 , thereby increasing the grip and improving the cut quality of each half. At the bottom of rotation, the blade  51  also promotes transport of the avocado halves once separated since the blade  51  spins in the same direction as avocados travel. This is advantageous since avocados are fairly lightweight and are only supported on the bottom tangents. 
         [0028]    To prevent fruit from moving during the cut, multiple powered O-ring belts  53  are provided above the fruit. Belts  53  extend from blade axles to a fixed axle on a wedge  55 , forward of the end of conveyors  41 . Belts  53  extend from the blade axles to a fixed axle ablve conveyors  41 . Wedge  55  is a stationary, generally V-shaped member for directing one avocado half left and the other right as illustrated in  FIG. 4A . Belts  53  are powered by pulleys  54  located on either side of blade  51  and contact the fruit on tangential surfaces. Pulleys  54  are slaved off the saw blade shaft, and as such, the contacting surfaces of belts  53  run in the same direction as the avocados. Upstream of saw  51 , belts  53  are horizontal and spaced along conveyor  41  to prevent stacked or under-ripe avocados from moving away from blade  51 ; downstream of saw  51 , belts  53  incline downward promote transfer of avocado halves through wedge  55  and down the chute in a controlled manner. Downstream belts  53  are generally parallel with the upper edge of wedge  55 . 
         [0029]    Referring to  FIG. 6 , transfer conveyor  61  is used to separate fruit halves and to transfer halves between the slicing station and squeezing station. Just after the avocados begin passing through saw  51  or afterwards, the bottom of the fruit is wedged apart laterally by wedge  55 . The flat bottom of the fruit half falls onto transfer conveyor belt  61 . Avocado halves must then be separated from a common drop point at the centerline of the transfer conveyor  61  to the outside edges of conveyor  61 . The transfer is accomplished by side guides  63  that direct the fruit from a common input to two parallel outputs. It is necessary in the squeezer section to have the fruit facing with the cut face down prior to entering the squeezer. In one embodiment, an optical sensor can be used to detect if an avocado is facing correctly by looking at the color. The outside skin is significantly darker that the color of the pulp, which is light green. In the event that the fruit is disoriented, then an escapement can automatically push the fruit toward the center of the conveyor  61 . The fruit will fall off the end of the conveyor  61  into a holding bin, where an operator can manually load it later. 
         [0030]    Referring to  FIG. 7 , which is a side view of the squeezing cell, avocados continue along the transfer conveyor  61  until they reach the depitting and squeezing station where: 1) the seed is removed; 2) the fruit pulp is separated from the skin; and 3) the remaining materials are taken away from the machine. The squeezing station has two parallel lanes that process each respective half of the avocado. Each lane is independently powered and controlled and utilizes a corrosion-resistant attachment chain  72  as the transport devices. The chain  72  is located above the transfer conveyor and is driven such that the bottom of the chain  72  travels in the same direction &amp; speed as the transfer conveyor  61 . 
         [0031]    Referring to  FIGS. 8A ,  8 B and  8 C, each chain attachment link contains a finger assembly, consisting of a hinged joint  81  and two flat fingers  83  attached to the pivot axis that act together to form a V-shape. Each finger assembly contains a center hinge pin  81 , two flat fingers  83 , each with a small slot (not visible) to improve friction, one or more torsion springs (not visible) to urge the fingers closed, a pin  85  welded perpendicular toward the outside of each finger  83 , and idler rollers (not visible) which ride on the pin  85 . These finger assemblies are attached to the chain  72  permanently or with removable fasteners for service and cleaning. 
         [0032]      FIGS. 9A ,  9 B, and  9 C illustrate an alternate embodiment of the finger assembly of  FIGS. 8A ,  8 B, and  8 C, consisting of common member  91 , two hinged joints  93 , and two flat fingers  95  attached to the pivot axes that act together to form a V-shape. Each finger assembly contains hinge pins  93 , two flat fingers  95 , each with a small slot (not visible) to improve friction, one or more torsion springs (not visible) to urge the fingers closed, a pin  97  welded perpendicular toward the outside of each finger  95 , and idler rollers (not visible) which ride on the pin  97 . 
         [0033]      FIGS. 10A ,  10 B, and  10 C illustrate an alternate embodiment of the finger assembly of  FIGS. 8A ,  8 B, and  8 C, consisting of slot joints  100 , and two concave fingers  105  attached to the pivot axis that act together to form a V-shape. Each finger assembly contains two pins  101 , a slot  103 , two concave fingers  105 , each with a small slot (not visible) to improve friction, one or more torsion springs (not visible) to urge the fingers closed, a pin  107  welded perpendicular toward the outside of each finger  105 , and idler rollers (not visible) which ride on the pin  107 . 
         [0034]    Referring back to  FIGS. 7 ,  8 A,  8 B, and  8 C, each pin  85  is captured above by an upper guide track  77 , and below by a lower guide track  78 . The gap distance between guides  77 ,  78  is used to limit the pivot angle from open to close between fingers  83  or the relative motion of just one finger. Initially, guide tracks  77 ,  78  ensure that the fingers are fully open by restricting the movement of pins  85  ( FIG. 8A ). Once the chain reaches a parallel attitude to the transfer conveyor  61 , guide tracks  78  are lowered, and pins  85  are no longer restricted. As a result, the torsion spring in the fingers causes the fingers to close and grip the avocado halves. The spring constant must be selected to provide sufficient torque to grip the avocado halves between the fingers, but must not be too great to cause premature extraction of the fruit. If there is an avocado half available, fingers  83  will close until they grip the fruit. ( FIG. 8B ). If a fruit is not available, lower guides  78  prevent the finger assembly from closing fully to avoid damage. 
         [0035]    As the avocados are gripped and conveyed along the chain path, the fruit passes over a slotted plate  74  so that the bottom surface of the avocado half is once again supported. The entry of the plate begins before de-seeder  73  and ends past de-seeder  75 . Each avocado half passes through two in-line de-seeders  73 ,  75  per lane. A de-seeder assembly  73 ,  75  consists of a powered blade with four points and this blade is attached to a drive shaft axis horizontal and perpendicular to the direction of travel. As the blade  73 ,  35  passes through the fruit, one or more points of the blade  73 ,  75  engage the seed and extract it from the fruit. 
         [0036]    After the seed has been removed and the avocado half leaves the skid plate  74 , the guides  77 ,  78  are configured to gradually force closure of the spring fingers  83 . The upper guides tracks  77  bend downward towards the lower guide tracks  78 . As the distance between the chain  72  and upper guides  77  is increased, a downward force is exerted on pins  85 . The downward force on pins  85  forces fingers  83  closer together ( FIG. 8C ). The lower guides  78  ensure that fingers  83  do not close more than a desired amount. The wedge action of the fingers  83  forces the avocado pulp to separate from the skin, where it falls down into a container, transport conveyor, or other similar transport method (not visible). Since the force on pins  85  can be significant, the pins  85  have roller bushings (not visible) intended to reduce slide friction. To improve the yield of extracted avocado fruit from skin, the finger assembly then passes through a secondary squeeze section  79  that applies significantly higher force to the fruit. 
         [0037]    Referring to  FIG. 10 , an optional second squeezer consists of idler rollers  113  on either side of the finger assembly path  112  that are mounted on a base  115  which pivots on the frame  117 . The other end of the base  115  is attached to a pneumatic cylinder  119  or similar device that can provide force. The pneumatic cylinder  119  force can be adjusted via regulator regardless of stroke and it can be attached to a valve actuator in order to retract the wheels for cleaning. Each roller  113  rolls on the outer sides of fingers  83  ( FIG. 8A ), pushing them tightly together. 
         [0038]    Referring back to  FIG. 7 , after the pulp has been extracted and the fruit is in a safe location, the guide tracks  77 ,  78  are arranged to force open the finger assemblies. The remaining products fall from the fingers  83 , into a waste container, transport conveyor, or other similar disposal method (not visible). While the fingers  83  are held in an open position, one or more nozzles  81  spray pressurized fluid toward the fingers in order to remove debris. The cleaning fluid usually contains water and sanitizer chemicals. The fingers  83  then travel in an open position on chain  72  to the initial starting point, and the process is repeated. 
         [0039]    The invention has significant advantages. By processing the avocados while they continuously travel on a conveyor belt, the manual labor associated with such a process is eliminated. Furthermore, the automated system allows the avocados to be processed at a high rate of speed, ensuring that pulp is removed from the avocados in a quick and efficient manner. 
         [0040]    While the invention has been described in only one of its forms, it should be apparent to those skilled in the art that it is not so limited, but is susceptible to various changes without departing from the scope of the invention.

Technology Classification (CPC): 0