Abstract:
Apparatuses and methods of picking up items from a first location and selectively releasing those items at one of multiple desired second locations are provided in which an item is either pierced, clamped, or stuck to a gripper without using vacuum pressure to maintain the grasp between the item and the pickup device. In several embodiments the items are grasped by piercing probes such as an expandable needle, a barbed needle or a screw. In other embodiments the items are clamped by tweezers or a gear and fingers combination. In a final embodiment, an item is grasped by being frozen to a temperature controllable surface.

Description:
[0001]    This application is a continuation-in-part (CIP) of co-pending U.S. patent application Ser. No. 10/262,223 to Winkelmolen, filed Oct. 1, 2002. 
     
    
     
       FIELD OF THE INVENTION  
         [0002]    The present invention relates to methods and apparatuses for picking up and transferring those items from a first location to a second location. More particularly, the present invention relates to methods and apparatuses for picking up semi-rigid or non-rigid items having a slippery surface and irregular shape (such as chicken parts or other food items) from a first location and selectively releasing the picked up items at one of multiple predetermined release locations.  
         BACKGROUND OF THE INVENTION  
         [0003]    In food processing facilities, it is typically necessary to select a single article/object or food item from a bulk load of such food items and to grade, or weigh or measure some attribute of the food item. This is done for purposes of pricing the food item or for meeting particular specifications related to the food item. Once the attribute for the food item has been determined, it is then often necessary to place the food item into a segregated location along with a group of other food items having the same or similar attribute(s). Historically, apparatuses and methods for determining attributes of food items have required that a single food item be removed from the bulk load at a first location, placed on a conveyor at a second location, and then moved via the conveyor to a device for measuring the attribute. Such apparatuses and methods have generally included an array of vacuum devices, each for picking up a single food item and transporting the food item from the first location to the second location.  
           [0004]    Although vacuum pick-up devices, such as those disclosed in U.S. Pat. No. 5,725,082 which is incorporated herein by reference, are extremely reliable for firmly grasping and transporting item bodies of semi-rigid or non-rigid structure and having a slippery surface and irregular shape, such as chicken parts, arrays of these devices are designed primarily for releasing items at a single, fixed location. This is because vacuum pick-up devices require application of significant and continuous suction on the item being transported, and thus a complex valve arrangement or some other means of terminating vacuum pressure at the desired release location is necessary when arrays of multiple pick-up devices are involved. When multiple possible release locations are available, the application and termination of vacuum pressure becomes even more complicated, and can add substantially to the overall size and cost of the machinery used in a food processing facility.  
           [0005]    As traditional apparatuses and methods for determining attributes do in fact transport and release each food item to a single fixed location on a conveyor, the use of vacuum pick-up devices has worked very well. Nevertheless, due to the recent invention of apparatuses and methods for product attribute measurement, as disclosed in currently-pending U.S. patent application Ser. No. 10/262,223 to Winkelmolen, incorporated herein by reference, which provide for item attribute measurement while the item is being transported from the bulk load and prior to release at a second location, it has become desirable to develop apparatuses and methods for picking up a food item at a first location and selectively releasing the food item at one of multiple possible second locations. Given the difficulties in permitting selective location release with the vacuum pick-up devices of the prior art, it is desirable to develop apparatuses and methods for picking up a food item at a first location and selectively releasing the food item at one of multiple possible second locations that do not utilize vacuum pressure to grasp the item.  
         SUMMARY OF THE INVENTION  
         [0006]    An object of the present invention is to provide apparatuses and methods for picking up a food item, or other object, at a first location and selectively releasing the food item at one of multiple possible second locations. A further object of the present invention is to provide apparatuses and methods for picking up a food item, or other object, at a first location and selectively releasing the food item at one of multiple possible second locations that are simple yet reliable in design, construction and operation. Yet another object of the present invention is to provide an array of apparatuses each for picking up a single food item, or other object, at a first location from a group of bulk items and selectively releasing the food item at one of multiple possible second locations.  
           [0007]    In order to overcome the difficulties with the prior art and achieve the above described objects, the instant invention provides several alternative embodiments of methods and apparatuses for picking up a food item at a first location and selectively releasing the food item at one of multiple possible second locations. The methods and apparatuses of the instant invention utilize unique gripper devices and/or unique methods of grasping/gripping objects that are vastly more versatile than the vacuum-controlled object pickup devices and object pickup methods of the prior art. The gripper devices and grasping methods of the instant invention allow for an array of pickup devices to each be individually controlled to release an item at one of numerous possible locations or bins without the need for complex valve arrangements as are required to supply continuous suction with the vacuum pickup devices and methods of the prior art.  
           [0008]    In several embodiments of the present invention, an item, such as a chicken part, is picked up by a piercing probe such as an expandable needle, a barbed ended spear, or a screw that protrudes from an object pickup device. In operation, the object pickup device is positioned over a conveyor or some other area holding items, i.e. chicken parts, in bulk. The object pickup device is moved into close proximity to the bulk chicken parts and the piercing probe, or gripper, is manipulated so that the gripper pierces the item and then continuously holds the item as the object pickup device is moved to a position where release of the item is desired. The gripper is then manipulated so that the piercing probe is withdrawn from the item and the item is released.  
           [0009]    In one embodiment of the instant invention, the piercing probe gripper includes an expandable needle similar to a balloon-tipped catheter tube used in angioplasty procedures. In the preferred embodiment, the expandable needle includes a generally rigid body constructed of steel, hard plastic, or any other suitable structural material. The needle body includes a sharpened or pointed rigid endpoint for piercing the item that is to be picked up. In the preferred embodiment of the expandable needle, a small section of the needle body, located relatively close to the endpoint, is constructed of rubber, an elastomer, or any other suitable material having elastic properties or otherwise capable of creating the desired expansion. Once the needle pierces the item that is to be picked up, the expandable section is expanded to form a bulge in the otherwise smoothed surface of the needle body and preventing premature disengagement of the item from the needle. The object pickup device then moves toward a desired release location and the expandable section of the needle body will be manipulated to collapse/remove the bulge, allowing the item to slip off of the needle.  
           [0010]    In another embodiment of the instant invention, the piercing probe gripper includes a barbed endpoint, similar to a spear or fish hook, located on the end of a generally rigid needle. In operation, the needle is manipulated to pierce the item that is to be picked up and the barbed endpoint will prevent the item from slipping off of the needle. The object pickup device then moves toward a desired release location and the needle is retracted into a cavity of the pickup device, causing the item to be biased against the outer surface of the pickup device and disengaging the barb from the item, thus allowing the item to slip off of the needle.  
           [0011]    In yet another embodiment of the instant invention, the piercing probe gripper includes a generally sharp-pointed threaded screw. In operation the object pickup device is located in close proximity to the item that is to be picked up, such that the endpoint of the screw gripper is in contact with the item. The screw gripper is then rotated in a direction that causes the screw threads to pierce and continue into the item, affixing the item to the screw. The object pickup device then moves toward a desired release location and the screw is rotated in the reverse direction causing the screw threads to retract from the item and ultimately causing the item to release from the screw.  
           [0012]    In several alternative embodiments of the instant invention, an item, such as a chicken part, is picked up by a gripper that does not necessarily pierce the surface of the item. In operation, the object pickup device is positioned over a conveyor or some other area holding items, i.e. chicken parts, in bulk. The object pickup device is moved into close proximity to the bulk chicken parts and the gripper is manipulated engage/grasp the outer surface of the item and then continuously hold the item as the object pickup device is moved to a position where release of the item is desired. The gripper is then manipulated so as to disengage the outer surface of the item and the item is released.  
           [0013]    In one embodiment of the instant invention, the outer-surface engaging gripper includes tweezers. In operation, the object pickup device is positioned in close proximity to the item that is to be picked up. The tweezers are extended outward from a cavity of the object pickup device, causing the fingers of the tweezers to spring apart from each other. The tweezers are then manipulated to locate the item between the fingers of the tweezers and the tweezers are retracted into the cavity of the object pickup devices, causing the fingers to clamp together and grasp the item. The object pickup device then moves toward a desired release location and the tweezers are extended outward from the cavity of the object pickup device, causing the item to be released.  
           [0014]    In another embodiment of the instant invention, the outer-surface engaging gripper includes a gear and finger. The gear and finger gripper operates in a similar fashion to the tweezers described above; however, combination of a gear and finger(s), allows for a wide variety of finger configurations, shapes and sizes that are not available with the generally straight finger design of tweezers. For example, a first finger can be fixed, while another finger is manipulated by the gear to open and close (or clamp) with the fixed finger. In another arrangement, a single finger can be utilized that opens and closes with a surface of the object pickup device. In operation, the object pickup device is positioned in close proximity to the item that is to be picked up. The gear is manipulated to place the finger(s) in an open position and the item is located in the opening. The gear is then manipulated to place the finger(s) in a closed position, causing the fingers to clamp together and grasp the item. The object pickup device then moves toward a desired release location and the gear is manipulated to open the fingers, causing the item to be released.  
           [0015]    In yet another embodiment of the instant invention, the outer-surface engaging gripper includes a temperature controllable surface. This embodiment is particularly useful in grasping food items, such as chicken parts, that inherently include a minimum moisture content. In operation the object pickup device is located in close proximity to the item that is to be picked up, such that the temperature controllable surface is in contact with the item. The temperature controllable surface is then adjusted to a cold temperature, freezing the moisture in the item and causing the item to freeze to the surface. The object pickup device then moves toward a desired release location and the surface is adjusted to a warmer temperature, thawing the point of engagement and releasing the item.  
           [0016]    The foregoing and other objects are intended to be illustrative of the invention and are not meant in a limiting sense. Many possible embodiments of the invention may be made and will be readily evident upon a study of the following specification and accompanying drawings comprising a part thereof. Various features and subcombinations of invention may be employed without reference to other features and subcombinations. Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawings, wherein is set forth by way of illustration and example, an embodiment of this invention.  
       
    
    
     DESCRIPTION OF THE DRAWINGS  
       [0017]    Preferred embodiments of the invention, illustrative of the best modes in which the applicant has contemplated applying the principles, are set forth in the following description and are shown in the drawings and are particularly and distinctly pointed out and set forth in the appended claims.  
         [0018]    [0018]FIG. 1 is a plan view of an attribute measurement and item separation process line that utilizes the apparatuses and methods for transferring objects of the present invention.  
         [0019]    [0019]FIG. 2 a  is a front cross-sectional view of an expandable needle pickup device of the present invention in a disengaged position.  
         [0020]    [0020]FIG. 2 b  is a front cross-sectional view of the expandable needle pickup device of FIG. 2 a  of the present invention in an engaged position.  
         [0021]    [0021]FIG. 3 a  is a front cross-sectional view of a tweezers pickup device of the present invention in a disengaged position.  
         [0022]    [0022]FIG. 3 b  is a front cross-sectional view of the tweezers pickup device of FIG. 3 a  of the present invention in an engaged position.  
         [0023]    [0023]FIG. 3 c  is a front cross-sectional view of a gripper assembly of the tweezers pickup device of FIGS. 3 a  and  3   b.    
         [0024]    [0024]FIG. 4 a  is a front cross-sectional view of a barbed piercing probe pickup device of the present invention in an engaged position.  
         [0025]    [0025]FIG. 4 b  is a front cross-sectional view of the barbed piercing probe pickup device of FIG. 4 a  of the present invention in a disengaged position.  
         [0026]    [0026]FIG. 4 c  is a front cross-sectional view of a gripper assembly of the barbed piercing probe pickup device of FIGS. 4 a  and  4   b.    
         [0027]    [0027]FIG. 5 is a front cross-sectional view of a screw pickup device of the present invention.  
         [0028]    [0028]FIG. 6 a  is a front cross-sectional view of a gear and finger pickup device of the present invention in a disengaged position.  
         [0029]    [0029]FIG. 6 b  is a front cross-sectional view of the gear and finger pickup device of FIG. 6 a  of the present invention in an engaged position.  
         [0030]    [0030]FIG. 7 is a front cross-sectional view of a temperature controllable surface pickup device of the present invention.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0031]    As required, detailed embodiments of the present inventions are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention, which may be embodied in various forms. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention in virtually any appropriately detailed structure.  
         [0032]    Referring to FIG. 1, an attribute measurement and item separation process line  80  is shown in which items  13  are to be picked up from a bulk supply delivery station,  12 , and transferred to one of multiple possible second locations depending upon the result of an attribute measurement (e.g., a particular weight, color, texture and/or hardness). In the embodiment shown in FIG. 1 and described below the measured attribute for an item is its weight. Item separation process line  80  includes delivery station  12 , product transfer station  28 , distribution conveyor  40 , and recirculation conveyor  54 , all connected to a support frame.  
         [0033]    As shown in FIG. 1, a series of item release locations, including distribution conveyor  40 , bins A′, B′, C′ and D′ for holding items, and recirculation conveyor  54 , are distributed around the circumference of product transfer station  28 . Bins A′, B′, C′ and D′ are intended for direct release of items from product transfer station  28 . As there is a finite amount of space located directly around the circumference of product transfer station  28 , it may be desirable to have additional bins located away from product transfer station  28 , at a location where additional space is available. Thus, distribution conveyor  40  is provided as a release location to move items away from product transfer station  28 . Additional bins A, B, C, D, E, F, G and H are located along distribution conveyor  40  for holding items deflected off distribution conveyor  40  by deflection arms  42 . An array of pickup units  21  are attached to product transfer station  28  via pickup arms  24 , which rotate about central shaft  26 . Each pickup unit includes pickup head  22  designed to pickup an item from delivery station  12  and selectively release the item and at one of the item release locations.  
         [0034]    The entire operation of processing line  80  is controlled by computer  38 . Bulk items  13 , such as chicken parts, will enter the processing line via a delivery conveyor (not shown) that will deposit items  13  on turntable  14  of delivery station  12 . As shown in FIG. 1, turntable  14  rotates in a clockwise direction and intersects the clockwise (or counterclockwise) rotation of product transfer station  28 . Pickup units  21  are located above turntable  14  to enable pickup of individual item  20  from bulk items  13  as pickup units  21  travel across turntable  14  at the point of intersection. Once a single item  20  has been picked up by pickup unit  21 , the clockwise rotation of transfer station  28  causes pickup arm  24  to move across load cell  82  that is incorporated into cam  84  through which pickup arm  24  travels. Computer  38  registers the weight from load cell  82 , which includes the weight of pickup unit  21  and the weight of the item, and subtracts from that weight the tare weight of the pickup unit that was measured by tare weight load cell  88  prior to pickup of the item to determine the weight of item  20 . Computer  38  then utilizes preprogrammed standards to determine the appropriate release location for item  20  based upon its weight, and releases the item from pickup unit  21  as the item rotates across the desired release location. If item  20  is to be placed in any of bins A′, B′, C′ or D′, it will be released directly into those bins from pickup unit  21 . If item  20  is to be placed in any of bins A-H however, it will be released at location P from pickup unit  21 , and distribution conveyor  40  will transport the item past point Q to point R, where the appropriate deflection arm  42  will be activated to deflect the item into the desired bin. When full, bins A′-D′ and A-H can be removed for further processing of the items within those bins. If an item  20  is outside of specifications or requires reworking it can be dropped onto recirculation conveyor  54  for a second pass through processing line  80 . Recirculation conveyor  54  can be used to simply recycle item  20  or a worker E′ can be stationed near recirculation conveyor  54  to rework or modify a item  20  which was determined to be outside of specifications.  
         [0035]    Referring now to FIGS. 2 through 7, several embodiments of pickup heads  22  of the present invention will be discussed. FIGS.  2 ( a, b ),  4 ( a, b ) and  5 ( a, b ) all show embodiments of pickup heads  22  that each includes a gripper that pierces an item as it grasps the item. Alternatively, FIGS.  3 ( a, b ),  6 ( a, b ) and  7  all show embodiments of pickup heads  22  that each includes a gripper that engages the outer surface of an item without necessarily requiring piercing of the item.  
         [0036]    [0036]FIGS. 2 a  and  2   b  show one embodiment of a piercing gripper of the instant invention in which pickup head  22  includes expandable needle  34  within housing  32 . Needle  34  is constructed similar to a balloon-tipped catheter tube that is commonly used in angioplasty procedures. Needle  34  includes a generally rigid body constructed of steel, hard plastic, or any other suitable structural material. The needle body includes sharpened or pointed rigid endpoint  35  for piercing the item that is to be picked up. Expandable section  36  of needle  34  is constructed of a material capable of expansion and contraction, such as rubber, an elastomer, or any other suitable material having elastic properties or otherwise capable of creating the desired expansion.  
         [0037]    In operation of the pickup head  22  shown in FIGS. 2 a  and  2   b , computer  38  controls endpoint  35  of needle  34  to pierce the item that is to be picked up, and then manipulates expandable section  36  to form a bulge in the otherwise generally smooth surface of needle  34 , as shown in FIG. 2 b . Because the bulge created by the expansion of section  36  is larger in diameter than the hole created in the item by the piercing needle, the bulge will prevent premature disengagement of the item from the needle. The item is then transported to the desired release location via product transfer station  28 , as described above with respect to FIG. 1, and computer  38  contracts the bulge of expandable section  36 , as shown in FIG. 2 a , allowing the item to slip off of the needle.  
         [0038]    It will be appreciated that expandable section  36  of needle  34 , and the manner in which it pierces and releases the object to be picked up, can be accomplished in a wide variety of arrangements and designs without departing from the scope of the present invention. For example needle  34  and expandable section  36  can be formed as a single integral unit, or can alternatively be formed as two separate components that are attached together. When needle  34  and expandable section  36  are formed as two separate components, expandable section  36  can be located within needle  34  or on the outer surface of needle  34 . If expandable section  36  is located within needle  34 , needle  34  may include apertures or slits to permit expandable section  36  to expand from within needle  34  and protrude outside of needle  34  to form the bulge. Needle  34  can be permanently affixed to housing  32 , such that the movement of pickup head  22  itself generates the force necessary to pierce the item. Alternatively, needle  34  can be equipped with a mechanism for extending and retracting needle from housing  32 , as is discussed below with respect to alternative embodiments of the instant invention. In such an arrangement, it is necessary only to position pickup head  22  above an item and then extend needle  34  from housing  32  to pierce the item.  
         [0039]    It will also be appreciated that the manner in which expandable section  36  is expanded and contracted can be accomplished by numerous means, all of which are within the scope of the instant invention, including but not limited to pneumatics, hydraulics, or mechanical expansion. In one embodiment, needle  34  is a hollow tube that is connected to a small air line. Computer  38  will activate the air supply to pressurize hollow needle  34  and cause section  36  to expand. Alternatively, section  36  can be expanded by actuation of a piston or some other mechanical member that protrudes in a direction generally orthogonal to the length of needle  34 .  
         [0040]    [0040]FIGS. 3 a ,  3   b  and  3   c  show an embodiment of the gripper of the instant invention in which pickup head  22  includes tweezers  334 . Tweezers  334  include two finger members  335  extending from a single intersection point  336  such that finger members  335  are in an open arrangement when no pressure is applied. Tweezers  334  are constructed of a metal or any other material having suitable elastic properties such that fingers  335  are capable of being positioned in a closed arrangement through the application of pressure to the outer sides of fingers  335  and returning to an open arrangement when such pressure is removed. Intersection point  336  is connected to a piston member  337  via extension member  338 . Piston member  337  is contained in cavity  330  of housing  32  with extension member  338  extending downward through housing opening  333  such that fingers  335  are capable of protrusion from housing  32  through opening  333 . Spring  339  is located in cavity  330  between the bottom wall of cavity  330  and piston member  337 , such that the compressive force of spring  339  will urge piston member  337  upward toward the top of cavity  330  when no downward force is applied to piston  337 . As shown in FIG. 3 b , the walls of opening  333  apply inward pressure to the outer sides of fingers  335  as piston  337  moves upward in cavity  330 , causing fingers  335  to close.  
         [0041]    In operation, computer  38  positions the object pickup device, including pickup head  22  of FIGS. 3 a  through  3   c , in close proximity to the item that is to be picked up. As is shown in FIG. 3 a , computer  38 , through application of air pressure through airline  331  into cavity  330 , forces piston  337  downward, compressing spring  339 , and allowing fingers  335  to extend outward through opening  333  and into an open arrangement. The object pickup device is then manipulated by computer  38  to locate the item between fingers  335  of tweezers  334 , and computer  38  releases the air pressure from cavity  330  causing piston  337  to be forced upward by spring  339  and causing fingers  335  to close together and grasp the item, shown in FIG. 3 b . Computer  38  then moves the object pickup device toward a desired release location and air pressure is applied to cavity  330  to force piston  337  downward to compress spring  339  and result in release of the item as fingers  335  open.  
         [0042]    It will be appreciated that the manner in which fingers  335  of tweezers  334  are opened and closed can be accomplished by a wide variety of embodiments, all of which are within the scope of the instant invention. For example, spring  339  could be place on the top of piston  337 , urging piston  337  downward, and thus vacuum pressure could be utilized to urge piston  337  upward. Alternatively, spring  339  could be eliminated and the position of piston  337  could be controlled simply by the application of increased pressure to move the piston downward, and the removal of pressure creating a vacuum to pull the piston upward. Other embodiments could be contemplated that eliminate piston  337  entirely and utilize other mechanical, or electromechanical means of opening and closing tweezers  334 .  
         [0043]    [0043]FIGS. 4 a ,  4   b  and  4   c  show an embodiment of the piercing probe gripper of the instant invention in which pickup head  22  includes needle  34  within housing  32 , and in which sharpened endpoint  35  of needle  34  further includes barb  37 . Barb  37  is constructed in similar fashion as a spear head or a fish hook. Needle  34  is connected to piston member  437 . Piston member  437  is contained in cavity  430  of housing  32  with needle  34  extending downward through housing opening  433  such that endpoint  35  is capable of protrusion from housing  32  through opening  433 . As shown in FIG. 4 b , the walls of opening  433  closely surround barb  37  when needle  34  is retracted. This allows bottom surface  434  of housing  32  to bias against the outer surface of an item being retained by barb  37  as needle  34  is retracted into housing  32 , causing the item to be released from barb  37 .  
         [0044]    In operation, computer  38  positions the object pickup device, including pickup head  22  of FIGS. 4 a  through  4   c , in close proximity to the item that is to be picked up. Computer  38 , through application of air pressure through an airline (not shown) into cavity  430 , forces piston  437  downward causing endpoint  35  and barb  37  of needle  34  to extend outward through opening  433 . The downward force of needle  34  will cause endpoint  35  and barb  37  to pierce the item that is to be picked up. Barb  37  will prevent the item from slipping off of needle  34 . Computer  38  then moves the object pickup device toward a desired release location and air pressure is released, or a vacuum is applied to cavity  430  to move piston  437  upward causing needle  34  to retract into opening  433  of housing  32 . As barb  37  of needle  34  is retracted into opening  433 , the item being held will bias against bottom surface  434  of housing  32 , causing barb  37  to be pulled out of the item.  
         [0045]    It will be appreciated that the manner in which needle  34  is extended and retracted from housing  32  can be accomplished by a wide variety of embodiments, all of which are within the scope of the instant invention. For example, a spring mechanism similar to that discussed with respect to FIGS. 3 a - 3   c  above can be utilized to move the piston up and down. Alternatively, needle  34  can be rigidly attached to housing  32  as is discussed with respect to FIGS. 2 a  and  2   b . Other embodiments could be contemplated that eliminate piston  437  entirely and utilize other mechanical, or electromechanical means of extending needle  34  into the item to be picked up.  
         [0046]    [0046]FIG. 5 shows another embodiment of the instant invention in which piercing probe gripper  22  includes generally sharp-pointed threaded screw  534  protruding from housing  32 . In operation, computer  38  positions the object pickup device in close proximity to the item that is to be picked up such that endpoint  535  of screw contacts the outer surface of the item. Computer  38  then causes screw  534  to rotate in a direction that will result in threads  537  piercing into the item and affixing the item to screw  534 . Computer  38  then moves the object pickup device toward a desired release location and screw  534  is rotated in the reverse direction causing threads  537  to retract from the item and ultimately causing the item to release from screw  534 .  
         [0047]    The rotation of screw  534  can be accomplished by any means now known or hereinafter contemplated. For example, a shaft can extend through housing  32  to be connected to screw  534 . The other end of the shaft can be connected to gears and a motor that is controlled by computer  38 . FIG. 5 shows screw  534  as having a fixed length a protrusion from housing  32 . Thus, in the embodiment of FIG. 5, as screw  534  rotates in either direction, its vertical position with respect to housing  32  will remain unchanged. Nevertheless, it will be appreciated that a similar pickup in which screw  534  extends and retracts from housing  32  as it is rotated is within the scope of the instant invention.  
         [0048]    [0048]FIGS. 6 a  and  6   b  show an embodiment of the gripper of the instant invention very similar to that shown in FIGS. 3 a - 3   c , with the primary difference being the replacement of the tweezers with gear and finger gripper  634 . The inclusion of the gear and finger gripper allows for a virtually unlimited variety of finger shapes and sizes, which are not as easily accomplished using a tweezer type claim or gripper. Gripper  634  includes two finger members  635  rotatably connected to housing via bearings  636 . Fingers  635  each include gear teeth members  632 , which mesh together with each other to provide a rotatable connection between the two fingers. One of fingers  635  is connected to piston member  637  via extension member  638 . Piston member  637  is contained in cavity  630  of housing  32  with extension member  638  extending downward through housing opening  633  such that extension member  638  protrudes from housing  32  through opening  633  to connect to fingers  635 . Spring  639  is located in cavity  630  between the bottom wall of cavity  630  and piston member  637 , such that the compressive force of spring  639  will urge piston member  637  upward toward the top of cavity  630  when no downward force is applied to piston  637 .  
         [0049]    In operation, computer  38  positions the object pickup device, including pickup head  22  of FIGS. 6 a  and  6   b , in close proximity to the item that is to be picked up. As is shown in FIG. 6 a , computer  38 , through application of air pressure through airline  631  into cavity  630 , forces piston  637  downward, compressing spring  639 , and causing extension  638  to extend outward through opening  633 . The outward/downward motion of extension  638  will cause gear teeth  632  to rotate such that fingers  635  rotate via bearings  636  into an open arrangement. The object pickup device is then manipulated by computer  38  to locate the item between fingers  635 , and computer  38  releases the air pressure from cavity  630  causing piston  637  to be forced upward by spring  639  and causing fingers  635  to close together and grasp the item, shown in FIG. 3 b . Computer  38  then moves the object pickup device toward a desired release location and air pressure is applied to cavity  630  to force piston  637  downward to compress spring  639  and result in release of the item as fingers  635  open apart from one another.  
         [0050]    It will be appreciated that the manner in which fingers  635  are opened and closed can be accomplished by a wide variety of embodiments, all of which are within the scope of the instant invention and which have been discussed above with respect to alternative embodiments of the instant invention.  
         [0051]    [0051]FIG. 7 shows an embodiment of the instant invention in which the outer-surface of the gripper includes temperature controllable surface  735  protruding from housing  32  of pickup head  22 . This embodiment is particularly useful in grasping food items, such as chicken parts, that inherently include a minimum moisture content. As shown in FIG. 7, the temperature controllable surface is the bottom surface of stainless steel capped thin wall tube  734  which extends through housing  32 . In operation the object pickup device is located via computer  38  into close proximity with the item that is to be picked up, such that temperature controllable surface  735  is in contact with the item. Computer  38  then adjust the surface  735  to a cold temperature by charging tube  734  with cold carbon dioxide, freezing the moisture in the item and causing the item to freeze to surface  735 . The object pickup device then moves toward a desired release location and the surface is adjusted to a warmer temperature by discharging the carbon dioxide from the tube, thawing the point of engagement and releasing the item.  
         [0052]    It will be appreciated that the means of providing variable temperature to surface alternative means of varying the temperature of surface  735  can be utilized without departing from the scope of this instant invention.  
         [0053]    In the foregoing description, certain terms have been used for brevity, clearness and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirements of the prior art, because such terms are used for descriptive purposes and are intended to be broadly construed. Moreover, the description and illustration of the inventions is by way of example, and the scope of the inventions is not limited to the exact details shown or described.  
         [0054]    Certain changes may be made in embodying the above invention, and in the construction thereof, without departing from the spirit and scope of the invention. It is intended that all matter contained in the above description and shown in the accompanying drawings shall be interpreted as illustrative and not meant in a limiting sense.  
         [0055]    Having now described the features, discoveries and principles of the invention, the manner in which the inventive apparatus and methods are constructed and used, the characteristics of the construction, and advantageous, new and useful results obtained; the new and useful structures, devices, elements, arrangements, parts and combinations, are set forth in the appended claims.  
         [0056]    It is also to be understood that the following claims are intended to cover all of the generic and specific features of the invention herein described, and all statements of the scope of the invention which, as a matter of language, might be said to fall therebetween.