Abstract:
A harvesting apparatus for harvesting generally spherical fruit by severing each fruit from its stem and conveying it using air flow into a receptacle. The harvesting apparatus includes a tubular body with a clamshell cutter for severing items of fruit from their stems, and a retractable throat that is able to restrict and then allow passage of the fruit. The apparatus further includes a control unit that can control the clamshell cutter and the throat. A funnel-shaped orifice is preferably included at the harvesting end of the tubular body. When a piece of fruit enters the harvesting end, it contacts the throat and blocks the airflow. The control unit senses the resulting pressure drop, and then activates the clamshell cutter while causing the throat to open so as to allow the piece of fruit to pass through the tubular body and into the receptacle.

Description:
FIELD OF THE INVENTION 
     The invention generally relates to agricultural harvesting apparatus, and more specifically to devices for automatically picking fruit. 
     BACKGROUND OF THE INVENTION 
     Harvesting devices are useful for reducing the amount of manual labor that is required to harvest agricultural crops. For example, a very large harvesting machine can typically be used by a single operator to harvest many acres of wheat, corn, tomatoes, and other crops where the plant itself is necessarily destroyed during the harvesting operation. However, the picking of tree-grown and vine-grown fruits, such as oranges and apples, where the parent plant sustains only minimal damage during harvesting, is typically done by hand, utilizing ladders, clippers (for example in the case of lemons), bags, and transfer boxes, and is therefore highly labor intensive. 
     Various automated devices are known for reducing the time and labor required for fruit picking, so as to lower the overall cost of the fruit that is harvested. However, these known fruit harvesting devices typically cut or twist the fruit from their stems using complex technology that requires substantial maintenance, such as whirling blades, iris blades, fruit grabbers and twisters, or even lasers. Moreover, the complexity of these known mechanisms significantly increases the likelihood that a malfunction could damage some of the harvest. In addition, many of these known devices do not automate the step of bringing each item of fruit to a receiving container after picking, and therefore they can provide only a minimal improvement in speed and efficiency as compared to picking by hand. 
     The high cost of manufacturing and maintaining these known automated picking devices, the limited reductions that they offer in labor costs, and the potential of damaging valuable crops if the device malfunctions, have largely prevented these automated picking devices from being economically practical. 
     SUMMARY OF THE INVENTION 
     An automated fruit harvesting apparatus is claimed that is simple to manufacture and to maintain, highly unlikely to malfunction or damage crops, and significantly faster and more efficient than previously known picking devices. The claimed apparatus automatically severs an item of fruit from its stem using a “clamshell” cutting mechanism that is located near the distal, or harvesting end of the tubular body. The claimed apparatus then uses air flow to convey the item of fruit through a tubular body and a flexible conduit, and into a receiving container. An inflatable throat located within the tubular body is able to alternately restrict and then allow the passage of each item of fruit. 
     An automatic control unit is able to sense a reduction in air pressure caused by contact between the piece of fruit and the inflatable throat. When the reduction in pressure is sensed, the automatic control unit actuates the clamshell cutting device, and then opens the inflatable throat so as to allow the harvested item of fruit to pass through the tubular body and flexible conduit, and into the receiving container. 
     One general aspect of the present invention is a harvesting apparatus for harvesting generally spherical fruit. The harvesting apparatus includes an elongated tubular body having a harvesting end and a discharge end, the elongated tubular body being configured so as to allow a piece of fruit to pass therethrough, a clamshell cutting device located within the harvesting end, the clamshell cutting device including a pair of opposing blades, the opposing blades being substantially shaped as partial spheres, with cutting edges that can be brought together by a pivotal motion of the blades, thereby severing the piece of fruit from an attached stem and allowing the piece of fruit to travel through the elongated tubular body and emerge from the discharge end, and a clamshell drive mechanism that can be actuated so as to cause the pair of opposing blades to pivot, thereby bringing their cutting edges together and then separating them. 
     In preferred embodiments, the clamshell drive mechanism includes a pneumatic piston and/or a linear solenoid. Some preferred embodiments further include a manual cutter actuator that enables a user to manually actuate the clamshell drive mechanism. In other preferred embodiments the harvesting end includes a funnel-shaped orifice that tends to guide pieces of fruit into the harvesting end of the tubular body. 
     In certain preferred embodiments the elongated tubular body is able to conduct a flow of air through its length, so as to draw a piece of fruit into the harvesting end and through the tubular body to the discharge end. Some of these embodiments further include a retractable throat, located within the harvesting end, and positioned so as to be in close proximity to the piece of fruit when the piece of fruit is drawn into the harvesting end, the close proximity thereby causing at least a partial blockage of the flow of air, and a consequent reduction of air pressure within the elongated tubular body. In some of these embodiments the retractable throat includes an inflatable member that is inflatable so as to block passage of the piece of fruit through the elongated tubular body, the inflatable member being deflatable so as to allow passage of the piece of fruit through the elongated tubular body. 
     Other of these embodiments further include a control unit that is able to sense the reduction of air pressure within the elongated tubular body, actuate the clamshell drive mechanism, thereby severing the piece of fruit from the stem, and cause the retractable throat to retract, thereby allowing the piece of fruit to pass through the tubular body to the discharge end. In some of these embodiments, the control unit includes an air pressure sensor that is able to sense the reduction of air pressure, the air pressure sensor being located between the retractable throat and the discharge end. In other of these embodiments, the control unit includes a timer, and is able to automatically repeat the actuation of the clamshell drive mechanism if the reduction of air pressure persists for a specified duration of time after the actuation of the clamshell drive mechanism. 
     Preferred embodiments further include a flexible conduit cooperative with the discharge end of the elongated tubular body, the flexible conduit being able to convey the piece of fruit from the discharge end to a receiving container. Other preferred embodiments further include comprising a receiving container suitable for collection of pieces of fruit after they have passed through the elongated tubular body and been discharged from the discharge end. 
     Another general embodiment is a harvesting apparatus for harvesting generally spherical fruit. The harvesting apparatus includes the following elements: 
     an elongated tubular body having a harvesting end and a discharge end, the harvesting end having a funnel-shaped orifice that tends to guide pieces of fruit into the harvesting end, the elongated tubular body being configured so as to enable conduction of a flow of air through its length, thereby drawing a piece of fruit into the harvesting end and through the tubular body to the discharge end; 
     a retractable throat, located within the harvesting end, and positioned so as to be in close proximity to the piece of fruit when the piece of fruit is drawn into the harvesting end, the close proximity thereby causing at least a partial blockage of the flow of air, and a consequent reduction of air pressure within the elongated tubular body; 
     a clamshell cutting device located within the harvesting end, the clamshell cutting device including a pair of opposing blades, the opposing blades being substantially shaped as partial spheres, with cutting edges that can be brought together by a pivotal motion of the blades, thereby severing the piece of fruit from an attached stem and allowing the piece of fruit to travel through the elongated tubular body and emerge from the discharge end; 
     a clamshell drive mechanism that can be actuated so as to cause the pair of opposing blades to pivot, thereby bringing their cutting edges together and then separating them; and 
     a control unit that is able to: 
     sense the reduction of air pressure within the elongated tubular body; 
     actuate the clamshell drive mechanism, thereby severing the piece of fruit from the stem; and 
     cause the retractable throat to retract, thereby allowing the piece of fruit to pass through the tubular body to the discharge end. 
     In preferred embodiments, the clamshell drive mechanism includes a pneumatic piston and/or a linear solenoid. Some preferred embodiments, further include a manual cutter actuator that enables a user to manually actuate the clamshell drive mechanism. In some of these embodiments, the retractable throat includes an inflatable member that is inflatable so as to block passage of the piece of fruit through the elongated tubular body, the inflatable member being deflatable so as to allow passage of the piece of fruit through the elongated tubular body. 
     In various preferred embodiments the control unit includes an air pressure sensor that is able to sense the reduction of air pressure, the air pressure sensor being located between the retractable throat and the discharge end. In certain preferred embodiments the control unit includes a timer, and is able to automatically repeat the actuation of the clamshell drive mechanism if the reduction of air pressure persists for a specified duration of time after the actuation of the clamshell drive mechanism. Other preferred embodiments further include a flexible conduit cooperative with the discharge end of the elongated tubular body, the flexible conduit being able to convey the piece of fruit from the discharge end to a receiving container. And still further preferred embodiments include a receiving container suitable for collection of pieces of fruit after they have passed through the elongated tubular body and been discharged from the discharge end. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention will be more fully understood by reference to the detailed description, in conjunction with the following figures, wherein: 
         FIG. 1  is an illustration of a preferred embodiment of the complete apparatus of the invention; 
         FIG. 2  is an enlarged oblique angle illustration of the harvesting end of the tubular body and the clamshell cutter device; 
         FIG. 3  is an exploded view illustration of a preferred embodiment of the clamshell cutter device and two cutter actuators; 
         FIG. 4A  is a side view illustration of a preferred embodiment of the invention that includes the clamshell cutter device and cutter actuators shown in  FIG. 3 , with the clamshell cutter device shown in a fully open configuration; 
         FIG. 4B  is a side view illustration of the preferred embodiment of  FIG. 4A , with the clamshell cutter device shown in a partially open configuration; 
         FIG. 4C  is a side view illustration of the preferred embodiment of  FIG. 4A , with the clamshell cutter device shown in a closed configuration; 
         FIG. 5  is an exploded view illustration of a preferred embodiment of the clamshell cutter device that includes a single cutter actuator; 
         FIG. 6A  is a side view illustration of a preferred embodiment of the invention that includes the clamshell cutter device and the cutter actuator shown in  FIG. 5 , with the clamshell cutter device shown in a fully open configuration; 
         FIG. 6B  is a side view illustration of the preferred embodiment of  FIG. 6A , with the clamshell cutter device shown in a partially closed configuration; 
         FIG. 6C  is a side view illustration of the preferred embodiment of  FIG. 6A , with the clamshell cutter device shown in a fully closed configuration; 
         FIG. 7A  is a side transparent illustration of the pneumatic cylinder and piston depicted in  FIG. 3 ; 
         FIG. 7B  is a side transparent illustration of the pneumatic cylinder and piston depicted in  FIG. 5 ; 
         FIG. 7C  is a side opaque illustration of a pull-type linear solenoid which is used in embodiments as an alternative to the cutter actuator shown in  FIG. 3 ; 
         FIG. 7D  is a side view illustration of a push-type linear solenoid which is used in embodiments as an alternative to the cutter actuator shown in  FIG. 5 ; 
         FIG. 8A  is a side view illustration of a cutter actuator including a pneumatic piston and cylinder, a rotatable drive component, and an actuator arm; 
         FIG. 8B  is an enlarged oblique angle illustration of the clamshell cutter device operated by the cutter actuator shown in  FIG. 8A ; and 
         FIG. 9  is a flow diagram illustrating a preferred embodiment of the method of use of the invention. 
     
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       FIG. 1  is an illustration of a preferred embodiment of the present invention. A tubular body portion  100  is shown with handles  102  and a cutter switch  103 . Also mounted upon the tubular body are a pressure sensor  104 , diaphragm manifold connections  106 , and a harvesting end  108 . The tubular body  100  is connected to a receiving container  112  by a flexible conduit  110 . The receiving container  112  has a closure top  113 . The top also forms the support for a vacuum pump  114 , diaphragm chamber  116 , and control unit  118 . In similar embodiments, the receptacle  112  and its top  113  are formed in other shapes, such as cylindrical. Preferably, where design and economy permits, certain of these components are constructed using composite materials that are both strong and light in weight. 
       FIG. 2  is an enlarged oblique angle illustration of a preferred embodiment the cutter head  200  at the harvesting end  108  of the tubular body  100 , which includes a clamshell cutter device  202 . The illustration shows the clamshell cutter device  202  in a partially opened position. When the cutter head  200  is placed near a piece of fruit, a flow of air into the cutter head pulls the piece of fruit into the cutter head  200 . When the piece of fruit enters the cutter head  200 , it blocks the flow of air and thereby causes a reduction of the air pressure within the cutter head  200 . A control unit senses this drop in pressure, and actuates the clamshell cutter device  202 , causing it to quickly close, thereby severing the piece of fruit from its stem. Note that throughout this document the term “piece of fruit” refers generically to any agricultural product for which each item is substantially spherical in shape and is harvested separately by disconnection of the item from a parent plant without causing substantial damage to the parent plant. Examples include tree grown fruits such as apples, oranges, and lemons, as well as vine grown agricultural products such as tomatoes. 
       FIG. 3  is an exploded illustration of a preferred embodiment of the clamshell cutter device  202  and two cutter actuators  300 . In this figure, each cutter actuator  300  includes a pneumatic piston  302  that drives a toothed rack  304 . A small gear  306  is affixed to each side of the top half of the clamshell cutter device  202 , as well as to each side of the bottom half of the clamshell cutter device  202 . The gears  306  on each side of the clamshell cutter device  202  are affixed near hinge joints that join the two halves of the clamshell cutter device  202 , enabling the clamshell cutter device  202  to open and close. The toothed rack  304  fits in between each pair of gears  306 . Each toothed rack  304  is attached to and driven by the pneumatic piston  302 . Linear movement of the toothed racks  304  by the pneumatic pistons  302  thereby causes the gears  306  to rotate, thereby causing the clamshell cutter device  202  to open and close. 
       FIG. 4A  is a side view illustration of the preferred embodiment of  FIG. 3 , shown with the clamshell cutter device  202  in a fully open configuration. A spherical piece of fruit  400  is shown being drawn into the cutter head  200  at the harvesting end of the tubular body  100 . Once the fruit  400  makes contact with an inflated throat  402 , the air flow through the tubular body  100  is blocked, the air pressure within the tubular body  100  drops, and a control unit senses the drop in pressure. In preferred embodiments, the control unit includes a pressure-sensing valve that is in communication with the cutter actuators  300 . 
     Upon sensing the pressure drop, the control unit causes air to flow into the pneumatic cylinder  404 , thereby pushing an enclosed piston  302  away from the clamshell cutter device  202 , and causing the toothed rack  304  to move backwards and rotate the gears  306  with which it is engaged in such a manner as to move the two halves of the clamshell cutter device  202  towards each other. 
       FIG. 4B  is a side view illustration of the preferred embodiment shown in  FIG. 4A , the clamshell cutter device  202  shown in a partially open configuration. In this figure, the piston  302  has begun to move, and the clamshell cutter device  202  has begun to close. The control unit also includes a diaphragm actuator that can inflate and deflate the diaphragm of the inflatable throat  402 . Upon sensing the drop in air pressure, the control unit allows air to escape from the inflatable throat  402 , thereby causing the throat  402  to collapse, and enabling the fruit  400  to pass through the now deflated throat  402  once the fruit stem is severed. 
       FIG. 4C  is a side view illustration of the preferred embodiment shown in  FIG. 4A , with the clamshell cutter device  202  in a closed configuration. The piston  302  is fully extended away from the clamshell cutter device  202 , and the toothed rack  306  has rotated the gears such that the top half and bottom half of the clamshell cutter device  202  have come together. Having previously sensed the drop in air pressure due to the proximity of the fruit  400  to the inflatable throat  402 , the control unit has allowed a sufficient amount of air to escape from the interior of the inflatable throat  402 , so as to enable the fruit  400  to pass through the inflatable throat  402 , and eventually through the flexible conduit  110  and into the receptacle  112 . Once the fruit  400  has passed through the inflatable throat  402  and into the interior of the tubular body  100 , air is able to flow through the tubular body  100  at a high enough volume and speed to enable normal activation of the mechanism to pick a subsequent item of fruit even before the previously picked item of fruit has reached the receptacle  112 . This allows for a high picking speed, and greatly enhances the economic practicality of the invention. 
       FIG. 5  is an exploded illustration of a preferred embodiment of the clamshell cutter device  202  that includes a single cutter actuator  500 . In this figure, the cutter actuator  500  includes a pneumatic piston  502  that drives a piston rod  503 , which in turn drives a ring  504 . A hinge joint  506  on either side of the clamshell cutter device  202  joins the two halves of the clamshell cutter device  202 , enabling the clamshell cutter device  202  to close about the hinge joint  506 . The ring  504  fits against the rear side of the clamshell cutter device  202 . The ring  504  is attached to and driven by a piston rod  503 , which in turn is driven by the pneumatic piston  502  when air is introduced into the system. 
       FIG. 6A  is a side view illustration of the preferred embodiment of  FIG. 5 , with the clamshell cutter device  202  shown in the fully open configuration. A spherical piece of fruit  400  is shown as being drawn into the harvesting end of the tubular body  100 . When the fruit  400  makes contact with the inflated throat  402 , it blocks the flow of air through the tubular body  100  and causes a drop in the pressure of the air in the tubular body  100 , which is sensed by a control unit. Upon sensing the pressure drop, the control unit causes air to flow into a pneumatic cylinder  600 . When air is fed into the cylinder  600 , the piston  502  contained therein moves towards the clamshell cutter device  202 . As a result, the driven ring  504  moves forward toward the rear side of the clamshell cutter device  202 . This forward motion of the ring  504  causes the top half and the bottom half of the clamshell cutter device  202  to rotate about the hinge joint  506  in a manner so as to move the top half and the bottom half of the clamshell cutter device  202  toward each other. 
       FIG. 6B  is a side view illustration of the preferred embodiment of  FIG. 6A , showing the clamshell cutter device  202  in a partially closed configuration. In this figure, the piston  502  has begun to move, and the clamshell cutter device  202  has begun to close. Upon sensing the drop in air pressure, the control unit also has allowed some air to escape from the interior of the inflatable throat  402 , thereby preparing for the fruit  400  to pass through the inflatable throat  402  once the fruit stem is severed. 
       FIG. 6C  is a side view illustration of the preferred embodiment of  FIG. 6A , showing the clamshell cutter device  202  in the fully closed configuration. The piston  502  is fully extended towards the clamshell cutter device  202 , and the ring  504  has pushed against the interior side of the clamshell cutter device  202  until it has completely closed. Having previously sensed the drop in air pressure due to the proximity of the fruit  400  to the inflatable throat  402 , the control unit has allowed a sufficient amount of air to escape from the interior of the inflatable throat  402  so as to enable the fruit  400  to pass through the inflatable throat  402  and eventually through the flexible conduit  110  and into the receptacle  112 . 
       FIG. 7A  is a transparent side view illustration of the pneumatic piston  700  and cylinder assembly  404  depicted in  FIG. 4A . A spring  702  contained within the cylinder  700  holds a pneumatic piston  302  in its rest position when no additional air has been introduced into cylinder  700 . When air is introduced into the cylinder  700 , the piston  302  moves away from the clamshell cutter device  202 , and the spring  702  is compressed. When the air pressure is released, the spring  702  returns the piston  302  to its usual position. In similar embodiments, the return spring is located elsewhere in the mechanism, and not inside of the pneumatic cylinder. 
       FIG. 7B  is a side view illustration of the pneumatic cylinder  704  and piston assembly  600  depicted in  FIG. 6A . A spring  706  located inside of the cylinder  704  holds the piston  502  in its rest position when no additional air has been introduced into the cylinder  704 . When air is introduced into the cylinder  704 , the piston  502  moves towards the clamshell cutter device  202 . The spring  706  is compressed, and when the air pressure is released a moment later, the spring  706  returns the piston  502  to its rest position. In similar embodiments, the return spring is located elsewhere in the mechanism, and not inside of the pneumatic cylinder. 
       FIG. 7C  is a side view illustration of a pull-type linear solenoid  708  which is used in place of a pneumatic cylinder and piston assembly in some embodiments that include the cutter actuator  300  shown in  FIG. 3 . When an electric voltage is applied to a solenoid coil contained within the solenoid body  710 , a magnetic field is created which pulls a magnetized armature rod  712  into the solenoid body  710 , and away from the clamshell cutter device  202 . When the magnetic field is switched off, a return spring located inside of the solenoid body returns the armature rod  712  to its rest position. In similar embodiments, the return spring is located elsewhere in the mechanism, and not inside of the solenoid body. 
       FIG. 7D  is a side view illustration of a push-type linear solenoid  714  that is used in place of a pneumatic cylinder and piston assembly in some embodiments that include the cutter actuator  500  shown in  FIG. 5 . When an electric voltage is applied to a solenoid coil within the solenoid body  716 , a magnetic field is generated which pushes a magnetized armature rod  718  outward from the solenoid body  716 , and toward the clamshell cutter device  202 . When the magnetic field is switched off, a return spring located inside of the solenoid body returns the armature rod  718  to its rest position. In similar embodiments, the return spring is located elsewhere in the mechanism, and not inside of the pneumatic cylinder. 
       FIG. 8A  is a side view illustration of a preferred embodiment of a cutter actuator  800  including a pneumatic cylinder and piston assembly  802 , a rotatable drive component  804  and an actuator arm  806 . In this embodiment, air forced into the pneumatic cylinder  802  pushes a piston  808  which forces the rotatable drive component  804  to pivot about a fulcrum  810 , thereby magnifying the range of motion of the piston  808  and pushing the actuator arm  806 . The actuator arm  806  pushes half of the clamshell cutter device  202  into the closed position. A similar arrangement of elements (not shown) located on the other side of the cutter head  100  simultaneously closes the other half of the clamshell cutter device  202 . When the air pressure is released a from the pneumatic cylinder  802 , a spring  812  returns the rotatable drive component  804  to its original rest position, thereby retracting the actuator arm  806  and opening the clamshell cutter device  202 . In this embodiment, the actuator arm  806  and rotatable drive component  804  do not require special maintenance or adjustments, and the spring action is accomplished using a typical hardware spring  812 , requiring no lubrication or unique specifications. 
       FIG. 8B  is an enlarged oblique angle illustration of the harvesting end of the preferred embodiment of  FIG. 8A . The cutter head  200  of this preferred embodiment includes a funnel-shaped intake  802 . The funnel-shaped intake  802  helps to position fruit against the inflatable diaphragm  402 , and to align the fruit&#39;s stem properly so as to avoid less efficient angular cuts. The funnel-shaped intake  802  also helps to separate one piece of fruit from other pieces of nearby fruit. 
       FIG. 9  is a flow diagram that illustrates a preferred embodiment of the method of use of the invention. A user connects the air flow to the tubular body  100  of the apparatus,  900 . Grasping the handles on the tubular body  100 , the user places the cutter near a piece of fruit  400 ,  902 . The suction caused by the air flow draws the fruit  400  into the harvesting end of the tubular body  100  and draws the fruit  400  into contact with the inflatable throat  402 ,  904 . Contact between the piece of fruit and the inflatable throat  402  blocks the flow of air through the tubular body  100 , and causes a drop in air pressure within the tubular body  100 . A control unit with a pressure sensor then senses the drop in air pressure  906 . Upon detecting this drop in air pressure, the control unit actuates the clamshell cutter actuator, and also begins releasing air from the diaphragm of the inflatable throat  402 ,  908 . The cutter actuator actuates the clamshell cutter device  202 ,  910 , while the inflatable throat  402  becomes sufficiently deflated so as to allow the fruit  400  to pass into the tubular body  100 ,  911 . 
     If the clamshell cutter device  202  fully severs the fruit  400  stem when the cutter actuator is automatically activated by the control unit, the severed fruit  400  passes through the tubular body  100 , through the flexible conduit  110 , and into the receptacle  112 ,  912 . In the rare event that the clamshell cutter device  202  does not succeed in fully severing the stem and freeing the fruit  400  from the tree within a preset amount of time after the cutter actuator has been automatically activated by the control unit, then the sensing unit timer will automatically reactivate the clamshell cutting mechanism,  913 , causing the clamshell cutting mechanism to open and re-close. This can be repeated as many times as is required to fully sever the fruit  400  stem. In similar embodiments, a manual cutter switch is provided so as to enable a user to actuate the clamshell cutter device manually. 
     Once the stem is fully severed, the fruit  400  can pass through the deflated throat  402  and onto the receptacle  112 ,  914 . When the receptacle  112  is filled with harvested fruit  400 , the user can replace the full receptacle  112  with an empty receptacle  112  through various means, or empty the receptacle  112  through various conveyor methodologies,  916 . When the user is completely finished using the harvesting apparatus, the user disconnects the air flow through the tubular body  100 ,  918 . 
     Other modifications and implementations will occur to those skilled in the art without departing from the spirit and the scope of the invention as claimed. Accordingly, the above description is not intended to limit the invention except as indicated in the following claims.