Patent Publication Number: US-2004045269-A1

Title: Tree harvester trunk seal

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS  
     [0001] This application is a continuation of application Ser. No. 10/201,561 filed Jul. 22, 2002, which is a continuation of application Ser. No. 09/665,233 filed Sep. 18, 2000, now U.S. Pat. No. 6,463,725, issued Oct. 15, 2002; which applications are incorporated herein by reference. 
    
    
     
       TECHNICAL FIELD  
       [0002] The present invention relates to harvesting systems, and more particularly, to harvesting systems having a sealing arrangement for maintaining the harvester a predetermined distance from the plant such that a seal is maintained between the harvester and one or more plants.  
       BACKGROUND  
       [0003] Mechanized harvesters are well known and provide several advantages over traditional manual harvesting methods. One of the advantages provided by mechanized harvesters is that the time required to remove and gather produce from each of the plants is significantly reduced. Likewise, the overall cost of removing and gathering the produce from each of the plants is significantly reduced. Because of these advantages, the use of mechanized harvesters to harvest fruit, vegetables, or other produce from various plants, such as trees or vines, has increased considerably.  
       [0004] Despite these advantages, there can be disadvantages associated with the use of mechanized harvesters. One of the disadvantages associated with mechanized harvesters is the potential to lose produce as it falls to the ground while the harvester advances through the field. To minimize the amount of produce that falls to the ground, however, many mechanized harvesters currently exist that have been equipped with conveyor systems that are positioned beneath the foliage of the tree or plant being harvested. These conveyor systems are constructed and arranged to catch produce as it falls from the plant and move it to a larger storage bin located on or adjacent to the harvester.  
       [0005] However, these conveyors are typically rigidly affixed to the harvester. Thus, in order for the conveyor to maintain a position proximate to the tree or plant to minimize the amount of produce lost, the operator is typically required to continuously adjust the path of the harvester. As a result, the distance between the harvester and the tree varies as the harvester advances.  
       [0006] In one scenario, as the distance between the harvester and the tree line increases, the amount of produce lost is also increased. Thus, the overall efficiency and cost-savings is reduced. In another scenario, as the distance between the harvester and the tree line decreases, the potential for damage to the harvester and/or the trees is increased.  
       [0007] Improvements in harvesters and seals used to maintain a seal between a first object and a second object are sought.  
       SUMMARY OF THE DISCLOSURE  
       [0008] The present disclosure generally relates to an apparatus for maintaining a seal between a first object and a second object. More particularly, the present disclosure is directed towards an apparatus for maintaining a first object a predetermined distance from a second object such that a seal is maintained between the first object and the second object.  
       [0009] In one aspect, the device comprises a retractable arm mounted to and extending from the first object towards the second object. The retractable arm is selectively positionable between at least a first position and a second position. The device also comprises a sealing arrangement mounted at a distal end of the retractable arm. The sealing arrangement includes a sealing member and a sensor configured to engage the second object and provide input to the retractable arm so as to maintain a predetermined distance between the distal end of the retractable arm and the second object. As a result, a seal is formed and maintained between the first object and the second object.  
       [0010] In one aspect, the sealing member comprises a plurality of overlapping pivot plates pivotably mounted at the distal end of the retractable arm. The overlapping pivot plates are further constructed and arranged to accommodate the second object as the first object travels along a first direction. Furthermore, in this aspect, the sensor comprises a sensor bar extending along the width of the distal end of the retractable arm. The sensor bar is configured to engage the second object as the first object travels along a first direction.  
       [0011] In an alternative aspect, the sealing member and the sensor comprise a plurality of overlapping pivot plates pivotably mounted at the distal end of the retractable arm. In this aspect, the plurality of overlapping pivot plates are constructed and arranged to accommodate the second object as the first object travels along a first direction.  
       [0012] The disclosure also relates to a harvester for gathering product from one or more plants. The harvester comprises a drive mechanism for automatically advancing the harvester along a first direction relative to the plants. A retractable arm or conveyor is mounted to and extends from the drive mechanism towards the plant. The retractable arm is selectively positionable between a first position and a second position. Furthermore, the harvester also comprises a sealing arrangement mounted at a distal end of the retractable arm. The sealing arrangement includes a sealing member and a sensor configured to engage the plants and provide input to the retractable arm so as to maintain a predetermined distance between the distal end of the retractable arm and the second object. As a result, a seal is formed between the harvester and each of the plants.  
       [0013] The harvester can also comprise an agitator constructed and arranged to engage the plants and remove produce from the plant as the harvester moves in the first direction. In this aspect, the agitator comprises at least one whorl arrangement capable of rotating and engaging the plants to forcibly remove produce from the plant as the harvester moves in the first direction. Each of the whorls are capable of rotating about a vertical axis substantially perpendicular to the ground surface about which the harvester travels. Furthermore, each of the whorls are capable of reciprocating in a linear motion substantially forward towards and backwards away from the plant being harvested.  
       [0014] In one aspect, the sealing member comprises a plurality of overlapping pivot plates pivotably mounted at the distal end of the retractable arm. The overlapping pivot plates are constructed and arranged to accommodate at least one of the plants as the harvester travels along a first direction. In this aspect, the sensor comprises a sensor bar extending from a distal end of the retractable arm. The sensor bar is configured to engage a lower portion of the plants as the harvester travels along a first direction.  
       [0015] In an alternative aspect, the sealing member and the sensor can comprise a plurality of overlapping pivot plates mounted at the distal end of the retractable arm. In this aspect, the plurality of overlapping pivot plates are constructed and arranged to accommodate a lower portion of the plants as the harvester travels along a first direction.  
       [0016] The above summary of the present invention is not intended to describe each illustrated embodiment or every implementation of the present invention. Other objects, features and advantages of the present invention will become more apparent in light of the following detailed description of exemplary embodiments thereof, as illustrated in the accompanying drawings.  
     
    
    
     BRIEF DESCIPTION OF THE DRAWINGS  
     [0017] The invention may be more completely understood in consideration of the following detailed description of various embodiments of the invention in connection with the accompanying drawings, in which:  
     [0018]FIG. 1 is side-elevational view of a harvester for removing produce from a tree having a trunk seal in accordance with the present disclosure;  
     [0019]FIG. 2 is a top view illustrating the harvester for removing produce shown in FIG. 1;  
     [0020]FIG. 3 is a side-elevational view illustrating a retractable arm for use with the harvester of FIG. 1 in accordance with the present disclosure;  
     [0021]FIG. 4 is an enlarged, side-elevational view illustrating a sealing arrangement disposed at a distal end of the arm of FIG. 3;  
     [0022]FIG. 5 is a top view illustrating one possible embodiment of the retractable arm shown in FIG. 3;  
     [0023]FIG. 6 is a top view illustrating a second possible embodiment of the retractable arm shown in FIG. 3;  
     [0024]FIG. 7 is an enlarged, segmented, top view of the retractable arm shown in FIGS. 3 and 5 illustrating a sensor bar in an unactuated state;  
     [0025]FIG. 8 is an enlarged, segmented, top view of the retractable arm shown in FIGS. 3 and 5 illustrating a sensor bar in an actuated state;  
     [0026]FIG. 9 is an enlarged, segmented, top view illustrating one possible embodiment of the sealing arrangement in accordance with the present disclosure; and  
     [0027]FIG. 10 is an enlarged, segmented, top view illustrating a second possible embodiment of the sealing arrangement in accordance with the present disclosure. 
    
    
     [0028] While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.  
     DETAILED DESCRIPTION  
     [0029] The present disclosure generally relates to an apparatus for maintaining a seal between a first object and a second object. More particularly, the present disclosure is directed towards an apparatus for maintaining a first object a predetermined distance from a second object such that a seal is maintained between the first object and the second object. While the present invention is not so limited, a more detailed understanding of the present invention will be gained through a discussion of the drawings in connection with the examples provided below.  
     [0030] As will become apparent from the discussion below in connection with the accompanying drawings, the present disclosure has particularized applicability to mechanized harvesters used to harvest produce from a plant or tree. However, it will be appreciated by those having skill in the art that the present disclosure is not limited to the specific embodiments discussed below. Rather, the present disclosure has general applicability to situations where it is desirable to maintain a seal between a first object and a second object.  
     [0031] Referring now to FIG. 1, there is illustrated a harvester  100  operating adjacent to a plant  102 . By way of illustration, the plant  102  shown in FIG. 1 is a citrus fruit tree, such as an orange or grapefruit tree. However, it should be understood that the embodiment shown in FIG. 1 is generally applicable to a variety of plants and trees, including various fruit trees as well as plants growing against a support structure, such as grapevines, or other similar plants or trees.  
     [0032] In one embodiment, the harvester  100  comprises a drive mechanism, such as a farm tractor or other similar device capable of moving through a grove or orchard of fruit trees  102 . As will be described below, the harvester  100  is constructed and arranged to harvest produce as it moves along through a grove of fruit trees  102 . In the embodiment illustrated in FIG. 1, a single harvester  100  is shown. However, preferably the harvester  100  can work in conjunction with a second harvester (not shown) while harvesting produce from one or more trees  102  in cooperation with the harvester  100 . In this embodiment, each harvester  100  moves along a row of trees  102  at substantially the same rate and on opposite sides of the same tree  102 . As a result, each harvester  100  removes produce from about approximately half of the tree  102 .  
     [0033] A retractable arm  112 , such as a conveyor  112   a , is mounted to the harvester  100 . The retractable arm  112  has a proximal end portion  118  at or near a first side  100   a  of the harvester  100 . Similarly, the retractable arm  112  has a distal end portion  116  opposite the proximal end portion  118  at or near a location furthest away from the proximal end portion  118 . The retractable arm  112  is pivotably mounted to the harvester  100  at point  117  located substantially near or at a second side  100   b  of the harvester  100 . The retractable arm  112  is mounted at point  117  using a pin and channel arrangement (not shown) as is commonly understood in the art. As a result, the retractable arm  112  is able to pivot about point  117  and slide up and/or down as the retractable arm  112  is extended or retracted as explained below.  
     [0034] As shown in FIG. 1, the retractable arm  112  extends away from the harvester  100 , such that it can extend beneath the foliage of the tree  102 . The retractable conveyor  112  is selectively positionable between a first position and a second position. In the first position, for example, the retractable arm  112  is fully extended. In the second position, the retractable arm  112  is fully retracted. Typically, the distance the retractable conveyor or arm  112  extends from the harvester  100  varies according to the spacing between the distance between each row of trees  102  in the orchard or grove. For example, the retractable arm or conveyor  112  is positionable such that the distal end portion  116  of the retractable arm  112  can be at least about 8 feet (about 2.4 meters), no more than about 13 feet (about 4.0 meters), and in a preferred embodiment approximately about 11 feet (about 3.4 meters) from the centerline CL (FIG. 1) of the harvester  100 . Thus, in the preferred embodiment, the distance the retractable conveyor or arm  112  extends from the centerline CL of the harvester  100  is optimized for harvesting produce from in an orchard or grove having 24 foot spacing.  
     [0035] Similarly, the retractable arm  112  has an overall width from the first side  158  of the retractable arm  112  to the second side  159  of the retractable arm  112  suitable to catch produce from the tree  102  while minimizing the amount of lost produce. Thus, for example, if used for citrus fruit trees, such as tree  102 , the retractable arm  112  has a width of at least about 15 feet (about 4.6 meters), no greater than about 30 feet (about 9.1 meters), typically about 20-24 feet (about 6.1-7.3 meters), and in a preferred embodiment about 22 feet (about 6.7 meters). In this embodiment, the retractable arm  112  is typically wide enough to span beneath at least about one or more trees  102  arranged in a row substantially parallel with the direction of travel of the harvester  100  as is commonly the case in a grove or orchard.  
     [0036] The harvester  100  can remove the produce from the tree  102  by shaking and/or agitating the foliage of the tree  102  or in any other suitable method. For example, in one embodiment, a vertical support shaft  104  extends upwardly from the harvester  100 . By “upwardly,” it is meant that in the orientation of the harvester  100  shown in FIG. 1, the support shaft  104  extends above a platform (not shown) of the harvester  100  and away from and substantially perpendicular to the ground  124 . The vertical support shaft  104  can be centered on the harvester  100 . Alternatively, the vertical support shaft  104  can be offset to one side of the harvester  100  as shown in FIG. 1 to facilitate removal of the fruit or produce from a tree.  
     [0037] One or more arm members  106  are independently rotatably mounted to the support shaft  104 . Each of the arm members  106  has a proximal end portion  105  at or near its point of attachment to the support shaft  104 . Similarly, each of the arm members  106  has a distal end portion  107  opposite the proximal end portion  105  at or near a location furthest away from the point of attachment to the support shaft  104 .  
     [0038] An agitator  109  is mounted at or near the distal end portion  107  of each of the arm members  106 . The agitator  109  is constructed and arranged to engage the tree  102  and forcibly remove the fruit or produce from the tree  102  as the harvester  100  moves along a first direction adjacent to the tree  102 . In one embodiment, the agitator  109  includes one or more whorl arrangements  109   a . As shown in FIGS. 1 and 2, each whorl arrangement  109   a  is rotatably mounted at or near the distal end portion  107  of each of the arm members  106 . Moreover, each whorl arrangement  109   a  includes a first set of fingers  108  rotatably mounted above each arm member  106  and a second set of fingers  110  rotatably mounted below each arm member  106  as shown in FIG. 1.  
     [0039] The first and second set of fingers  108 ,  110  are constructed and arranged to engage the tree  102 . For example, the first and second set of fingers  108 ,  110  are configured to rotate in plane substantially parallel to the ground surface  124  about which the harvester  100  travels. Similarly, the first and second set of fingers  108 ,  110  are capable of reciprocating in a linear motion along a direction of travel from the proximal end  105  to the distal end portion  107  of each arm member  106 . As a result, the whorl arrangement agitates the foliage of the tree  102  to forcibly remove the fruit from the foliage of the tree  102  as the harvester  100  advances in a first direction adjacent to the tree  102 .  
     [0040] A sealing arrangement  114  is provided at the distal end  116  of the retractable arm or conveyor  112  to maintain a seal between the harvester  100  and the tree  102 . Specifically, the sealing arrangement  114  maintains the distal end  116  of the retractable conveyor  112  a predetermined distance from a lower portion or trunk  120  of the tree  102 . As a result, a seal is maintained between and the tree trunk  120  the distal end  116  of the retractable arm  112 .  
     [0041] The sealing arrangement  114  includes a sealing member and a sensor configured to engage the lower portion or trunk  120  of the tree  102 . By “engage,” it is meant that the sensor contacts or comes into close association or connection with the lower portion or trunk  120  of the tree  102 . In so doing, the sensor is capable of controlling the retractable arm  112  such that a seal is maintained between the harvester  100  and the trunk  120  of the tree  102 . As a result, the amount of produce or fruit lost during harvesting is minimized. Furthermore, the operator of the harvester  100  is free to focus on advancing the harvester  100  through the grove or orchard of trees  102 . The sealing arrangement  114  will be discussed in greater detail below in conjunction with FIG. 4.  
     [0042] Referring now to FIG. 3, a side-elevational view of the retractable arm  112  is shown. The illustrated retractable arm  112  is generally rectangular and extends away from the harvester  100  and beneath the foliage of the tree  102 . FIG. 5 illustrates a top view of the retractable arm  112 . The retractable arm  112  has a first side  158  and a second side  159  opposite the first side  158 . In one embodiment, the retractable arm  112  can be generally comprised of one or more sections  161 ,  162 ,  163 ,  164 ,  165  that span the width of the retractable arm or conveyor  112  from the first side  158  to the second side  159 . In this embodiment, each of the sections  161 ,  162 ,  153 ,  164 ,  165  can include one or more individual, collapsible panels. For example, conveyor section  161  includes individual, collapsible panels  161   a ,  161   b ,  161   c ,  161   d , and  161   e . The individual, collapsible panels  161   a ,  161   b ,  161   c ,  161   d , and  161   e  collapse longitudinally along the length of the retractable arm  112  from the proximal end portion  118  to the distal end portion  116 . As a result, the retractable arm  112  can telescopically extend or retract longitudinally along the length of the retractable arm  112  from the proximal end portion  118  to the distal end portion  116 .  
     [0043] In an alternative embodiment, the retractable arm  112  can be comprised of a singe section without individual, collapsible panels as described above. In this embodiment, the retractable arm  112  is configured to selectively extend or retract longitudinally along the length of the retractable arm  112  in a non-telescopically fashion.  
     [0044] In the embodiment shown in FIG. 5, the arm  112  is extended and/or retracted using a hydraulic motor  136  that drives a chain  134  coupled to at least one sprocket (not shown) disposed at the proximal and distal end portions  116 ,  118  of the arm  112 . The chain  134  extends the length of the retractable conveyor  112 . Furthermore, a second hydraulic motor and chain assembly can be situated along the second side  159  of the arm  112 . In so doing, the arm  112  can be extended or retracted evenly. However, it should be understood that the hydraulic motor and chain arrangement can be arranged at any location suitable to extend or retract the arm  112 . For example, the hydraulic motor and chain arrangement can be arranged beneath the arm  112 .  
     [0045] In an alternative embodiment shown in FIG. 6, the arm  112  is extended and/or retracted using one or more hydraulic cylinders  172 ,  174  coupled to proximal and distal end portions  116 ,  118  of the arm  112  (FIG. 3). In the embodiment shown, the hydraulic cylinders  172 ,  174  are arranged along the first and second sides  158 ,  159  of the arm  112 . However, it should be understood that the hydraulic cylinders  172 ,  174  can be arranged in any position suitable to extend or retract the arm  112 . For example, at least two phased hydraulic cylinders can be positioned along the first and second sides  158 ,  159  of the arm  112 . In still yet another embodiment, one or more hydraulic cylinders  172 ,  174  can be arranged above or beneath the arm  112 . Preferably, where more than one hydraulic cylinder is used to extend or retract the retractable arm  112 , the hydraulic cylinders  172 ,  174  can be phased hydraulic cylinders, such as those manufactured by Prince Manufacturing Corporation located in North Sioux City, S. Dak. In so doing, the arm  112  can be extended or retracted evenly.  
     [0046] Using either the hydraulic motor  136  and chain  134  assembly or the hydraulic cylinders  172 ,  174 , the arm  112  can be selectively extended or retracted. For example, in the embodiment illustrated in FIGS. 5 and 6, as the arm  112  extends, the overlap between the individual, collapsible panels of each of the conveyor sections  161 ,  162 ,  163 ,  164 , and  165  is decreased. Conversely, as the arm  112  retracts, the overlap between the individual, collapsible panels of each of the conveyor sections  161 ,  162 ,  163 ,  164 , and  165  is increased.  
     [0047] The retractable arm or conveyor  112  has at least one height control gauge  122  configured to allow the retractable arm or conveyor  112  to move along the ground  124  at a preferred height with the harvester  100 . In the embodiment shown in FIG. 3, the height control gauge  122  is constructed as a wheel having a cylindrical center portion  122   a , and two opposed frustro-conical end portions  122   b ,  122   c . However, it will be understood that the height control gauge  122  can have any shape, including the shape of a convention cylindrical wheel or a spherical wheel. The shape of the wheel  122  as shown in FIG. 3 allows the conveyor  122  to extend and retract with minimal resistance from the ground  124 .  
     [0048] Referring now to FIG. 4, a sealing arrangement  114  is provided at the distal end  116  of the retractable arm  112 . The sealing arrangement  114  includes a sealing member  129  and a sensor  131  configured to engage the lower portion or trunk  120  of the tree  102 . By “engage,” it is meant that the sensor  131  contacts or comes into close association or connection with the lower portion or trunk  120  of the tree  102 . In so doing, the sensor  131  is able to control the retractable arm  112 . By “control,” it is meant that the sensor  131  is configured to provide input to either the hydraulic motor  136  or the hydraulic cylinders  172 ,  174  to selectively extend and retract the retractable arm  112  in accordance with a pressure being applied to the sensor such that a seal is maintained between the harvester  100  and the tree trunk  102 .  
     [0049] In a first embodiment, the sealing member  129  includes a plurality of overlapping pivot plates or fish scale members  130 . By “overlapping,” it is meant that the leading edge of each of the pivot plates are positioned above or beneath a rear edge of an adjacent pivot plate such that no gap exists between any two adjacent pivot plates. While the illustrated sealing member  129  includes a plurality of overlapping pivot plates, it should be understood that the sealing member  129  can be any suitable member for maintaining a seal between the distal end  116  of the retractable arm  112  and the tree  102 , such as a rubber seal member or a brush-like member having bristles that form a seal. The overlapping pivot plates  130  extend from the distal end  116  of the retractable arm  112 . The pivot plates  130  are constructed and arranged to accommodate a desired object as the harvester  100  advances in a first direction. By “accommodate,” it is meant that the pivot plates  130  cooperate to conform to the contour of the desired object, thereby forming a seal between the harvester  100  and the object. In the embodiment shown, the pivot plates  130  cooperate to conform to the contour of the tree trunk  120 , thereby forming a seal between the harvester  100  and the tree trunk  120 .  
     [0050] Furthermore, in this first embodiment, the sensor includes a sensor bar  132  extending from the distal end portion  116  and along the width of the retractable conveyor  112 . The sensor bar  132  is mounted at the distal end portion  116  of the retractable conveyor  112  by cooperating linkage arms  145  as shown in FIG. 4. The sensor bar is generally a straight, flat or tubular member. It should be understood, however, that the sensor bar  132  is not intended to be limited to such arrangements and can generally take on any suitable configuration for engaging the tree trunk  120 . Preferably, the sensor bar  132  extends from the first end  158  of the conveyor  112  to the second end  159  of the conveyor  112 .  
     [0051] As shown in FIG. 5, the sensor bar  132  has a leading end portion  132   a  and a trailing end portion  132   b . In one embodiment, the leading end portion  132   a  extends beyond the first end  158  of the conveyor  112  and the trailing end portion  132   b  extends beyond the second end  159  of the conveyor  112 . Alternatively, sensor bar  132  can have a length approximately equal to about the width of the retractable arm  112 . The leading end portion  132   a  defines an arcuate or curved region of the sensor bar  132 . Accordingly, as the harvester  100  advances along a row of trees, the leading end portion  132   a  gradually engages an oncoming tree and decreases the tendency of the sensor bar to become snagged. Similarly, the trailing end portion  132   b  defines an arcuate or curved region of the sensor bar  132 . As a result, as the harvester  100  advances along a row of trees, the trailing end portion  132   b  gradually disengages the tree trunk  120 . Thus, the sensor bar  132  allows an operator to continuously drive the harvester  100  adjacent to the trees  102  within a predetermined distance such that the pivot plates  130  maintain a seal with the trees  102 . Similarly, the sensor bar  132  also prevents damage to the pivot plates  130  as the harvester  100  advances along the trees  102 .  
     [0052] Preferably, the sensor bar  132  is mounted at the distal end portion  116  of the retractable arm  112  using at least about two (2) pairs of cooperating parallel linkage arms  145 . However, it will be understood by those having ordinary skill in the art that the number of cooperating parallel linkage arms  145  used to support the sensor bar  132  can be varied according to the weight and width of the conveyor  112  as well as other considerations. Each pair of cooperating parallel linkage arms  145  includes an upper linkage arm  144  and a lower linkage arm  146 . As shown in FIG. 4, the lower linkage arm  146  is pivotably connected to the distal end portion  116  of the retractable arm  112  at pivot point  148 . As a result, the sensor bar  132  is able to pitch or rotate in relation to the distal end portion  116  of the arm  112 . Similarly, the plurality of overlapping pivot plates  130  can also pitch or rotate to guide the produce towards the conveyor or arm  112  as it falls from the tree  102 . Preferably, the sensor bar  132  is configured and arranged substantially perpendicular to the trunk  120 .  
     [0053] Moreover, the upper and lower linkage arms  144 ,  146  are biased such that the sensor bar  132  is fully extended from the distal end portion  116  of the retractable arm  112 . For example, as shown in FIGS. 5 and 6, a spring  170  biases the sensor bar  132  such that it is fully extended from the distal end portion  116  of the arm  112 . An adjustable chain (not shown) is provided to allow the distance or space between the sensor bar  132  and the distal end portion  116  of the arm  112  to be either increased or decreased so that the desired degree of sealing overlap can be set.  
     [0054] As shown in FIG. 8, the upper and lower linkage arms  144 ,  146  are constructed and arranged to allow the sensor bar  132  to move towards the distal end portion  116  when a force F (FIG. 8) is applied to the sensor bar  132  in a direction towards the retractable conveyor  112 . The force F is typically applied to the sensor bar  132  as the sensor bar  132  engages the tree  102 . Accordingly, as the retractable arm  112  is moved closer to the tree  102 , the force F acting on the sensor bar  132  is increased. Conversely, as the retractable arm  112  is moved away from the tree  102 , the force F acting on the sensor bar  132  is reduced. As shown, the linkage arms  144 ,  146  preferably are arranged such that they are not perpendicular to the distal end portion  116  when fully extended. Thus, when the sensor bar  132  engages the tree  102 , the upper and lower linkage arms  144 ,  146  can move towards the distal end portion  116  of the arm  112  with minimal resistance and strain on the sensor bar  132  and/or the linkage arms  144 ,  146 .  
     [0055] As can be seen in FIGS. 7 and 8, a connecting member  156  mechanically couples the sensor bar  132  to a linkage rod assembly  152 . The linkage rod assembly  152  extends along the second end  159  of the arm  112 . However, it should be understood that the linkage rod assembly  152  and the connection member  156  can be arranged at any suitable location along the sensor bar  132 . Furthermore, the linkage rod assembly  152  is also coupled to an actuating assembly  154  that is configured to selectively extend or retract the arm  112 .  
     [0056] In one embodiment, the actuating assembly  154  includes a conventional micro switch, such as a solenoid switch that actuates the conveyor  112 . The actuating assembly  154  is selectively positionable between a first, second, and third or neutral state. In the first state, the actuating assembly  154  is triggered to retract the conveyor  112 . In the second state, the actuating assembly  154  is triggered to extend the conveyor  112 . In the third state (e.g., between the first and second states), the actuating assembly  154  is not triggered and the conveyor  112  is, therefore, not extended or retracted.  
     [0057] For example, as the sensor bar  132  is compressed by a force F (e.g. a tree  102 ) as shown in FIGS. 8 and 9, the linkage rod  152  urges the actuating assembly  154  into its first state to retract the arm  112 . The actuating assembly  154  provides input to either the hydraulic motor  136  or the hydraulic cylinders  172 ,  174 , thereby retracting the arm  112 . The arm  112  retracts until the arm  112  is completely retracted or until the actuating assembly  154  reaches its neutral state. The neutral state is achieved when a predetermined force is applied to the sensor bar  132  that allows the overlapping pivot plate assembly  130  to form an adequate seal around the tree  120  without risking damage to the sensor bar  132  or the overlapping pivot plates  130 .  
     [0058] Conversely, as the arm  112  retracts, thereby reducing the force F exerted against the sensor bar  132 , the linkage rod  152  urges the actuating assembly  154  into its second state to extend the conveyor  112 . The actuating assembly  154  again provides input to the either the hydraulic motor  136  or the hydraulic cylinders  172 ,  174 . However, in this case, the hydraulic motor  136  or the hydraulic cylinders  172 ,  174  cause the conveyor  112  to extend. The conveyor  112  extends until the conveyor  112  is completely extended or until the actuating assembly  154  reaches its neutral state. As discussed above, the neutral state is achieved when a predetermined force is applied to the sensor bar  132  that allows the overlapping pivot plate assembly  130  to form an adequate seal around the tree  120  without risking damage to the sensor bar  132  or the overlapping pivot plates  130 .  
     [0059] As discussed above, the sealing arrangement  114  also includes a sealing member  129 . For example, in the embodiment illustrated in FIG. 9, the sealing member  129  includes a plurality of overlapping pivot plates or fish scale members  130 . The overlapping pivot plates  130  are pivotably mounted at the distal end  116  of the retractable arm or conveyor  112 . The pivot plates  130  are constructed and arranged to accommodate a desired object as the harvester  100  advances in a first direction. By “accommodate,” it is meant that the pivot plates  130  cooperate to conform to the contour of the desired object, thereby forming a seal between the harvester  100  and the object. A coil spring  150  is disposed beneath each of the overlapping pivot plates  130  (FIG. 4). As a result, each of the overlapping pivot plates  130  are spring biased such that they extend away from the distal end  116  of the conveyor  112 .  
     [0060] Furthermore, as shown in FIG. 9, the overlapping pivot plates  130  extend beyond the sensor bar  130 . Thus, as the harvester  100  advances adjacent to the trunk  120  of a tree, the sensor bar  132  engages or rubs against the trunk  120  of the tree. Similarly, the pivot plates  130  also engage the trunk  120  of the tree  102 . As can be seen from FIG. 9, the overlapping pivot plates  130  cooperate to form a seal against the tree trunk  120 . Preferably, the overlapping pivot plates  130  cooperate to form a seal about a centerline L of the tree  102 .  
     [0061] In a second embodiment illustrated in FIG. 10, the sensor includes a rotary sensor or switch  176  as is commonly understood in art. In this embodiment, one or more rotary sensors or switches  176  can be coupled to a corresponding one or more of the pivot plates  130 . In this embodiment, the sensor bar  132  is not required. However, it will be understood by those of ordinary skill, that bar similar in construction to the sensor bar  132  can be used as a guard to protect the distal end  116  of the conveyor  112  as well as the pivot plates  130 .  
     [0062] Preferably, one or more of the overlapping pivot plates  130  are pivotably mounted at the distal end  116  of the conveyor  112  using a rotary switch  176 . The rotary switch  176  is coupled to an actuating assembly  154 , such as a micro switch, that is configured to selectively extend or retract the conveyor  112 . As discussed above, the actuating assembly  154  is selectively positionable between a first, a neutral, and a second state. The rotary switch  176  provides input to the actuating assembly  154  according to the angular displacement of the corresponding pivot plate. In the first state, the actuating assembly  154  is triggered to retract the arm  112 . In the neutral state, the actuating assembly  154  is not triggered and the arm  112  is, therefore, not extended or retracted. In the second state, the actuating assembly  154  is triggered to extend the arm  112 .  
     [0063] For example, as the harvester  100  advances adjacent to the tree trunk  120 , the leading edges  131  of the pivot plates  130  engages the tree trunk  120  as shown in FIG. 10. The pivot plates  130  corresponding to the location of the tree trunk  120  are rotated. As the pivot plates  130  are rotated, the actuating assembly  154  is switched from its neutral state to its first state. Accordingly, the arm  112  is retracted.  
     [0064] Conversely, when all of the pivot plates  130  are fully rotated, the actuating assembly  154  is switched into its second state. Accordingly, the conveyor  112  is extended. The arm  112  extends until it is fully extended or until the actuating assembly  154  is switched to its neutral state.  
     [0065] Moreover, as discussed above, the harvester  100  can work in conjunction with a second harvester (not shown) while harvesting produce from one or more trees  102 . In this embodiment, each harvester  100  moves along a row of trees  102  at substantially the same rate and on opposite sides of the same tree  102 . As a result, each harvester  100  removes produce from about approximately half of the tree  102 . Furthermore, the sealing arrangement  114  as described above forms and maintains a seal between each tree  102  and both harvesters  100  while advancing adjacent to the trees  102 , thereby minimizing the amount of produce lost.  
     [0066] As a result of this arrangement, the overlapping pivot plates  130  are able to form a seal between harvester  100  and the tree trunk  120 . More specifically, the overlapping pivot plates  130  form a seal between the distal end  116  of the conveyor  112  and a centerline L of the tree trunk  120 .  
     [0067] The above specification and embodiments are believed to provide a complete description of the manufacturer and use of particular embodiments of the invention. Many embodiments of the invention can be made without departing from the spirit and scope of the invention, which is limited by the attached claims.