Blueberry Picking Machine

The use of straddle-type blueberry picking machines is well known today. These machines employ a substantially U-shaped elevated ground contacting frame which is usually self-propelled. The fruit bearing bushes are usually planted in spaced rows. The machine then straddles each row with the blueberry bushes passing through a longitudinal opening in the center of the machine. In order to dislodge the ripened berries from the branches of the bush, arms have been used which project out from each side into the longitudinal opening to agitate the bushes as the machine moves along the row. Others have suggested the use of freely rotating spaced drums with fingers projecting from the outer surface which roll along the bush at the same speed as the harvesting machine passes over the ground. The drums are biased inwardly to force the drums into contact with the surface of the bushes. Fingers projecting from the drums comb the surface of the bushes and knock the ripened berries off the branches.

In this description, blueberries and blueberry bushes will be used as a representative crop bearing bush. The invention, however, is not so limited. The term "blueberry" is used as a generic expression for all types of berries, fruits, beans, nuts, vegetables, and the like, which grow on bushes, trees and vines and which can be harvested mechanically by a machine passing over the crop bearing plant.

In order to improve the harvesting with straddle-type harvest machines employing freely rotating shakers or brush-like members, means have been used to cause the shakers to vibrate or twist as they roll along the bushes. For example, Rust U.S. Pat. No. 3,184,908 has a pair of laterally and longitudinally spaced, vertically oriented shakers fixed to a ground contacting frame. A pair of spaced crankshafts connected by an endless chain extend across the top of the frame. Each shaker is rotatably connected to 180.degree. opposed cranks on the crankshafts. The crankshafts are driven by a power take off from a tractor which causes the shakers to move up and down as the shakers roll along in contact with the fruit bearing plants. When using this type of assembly, the drive mechanism for the shakers can be loaded down when the rods or fingers on each shaker enter into a bush with heavy vegetation. Also, the shaker assembly is directly attached to the frame which can cause substantial vibration of the frame during operation of the picker.

Christie et al. U.S. Pat. Nos. 3,325,984 and 3,385,042 disclose a straddle-type picker having a pair of freely rotatable drums which support a plurality of projecting bush contacting and penetrating fingers. Each of the drums is freely rotatable and moves along the row of bushes at the same rate that the frame of the machine passes over the ground. Each of the shakers has its own vibrating unit which rotates an eccentric connected to the central shaft of the drum. Both the frequency and amplitude of the motion of the shakers is manually adjustable by changing the position of mechanical linkages. Again, as in the previously described picker, the picking action can be erratic, depending upon the density of the vegetation in the bush. Also, drum-type pickers have a tendency to roll along the surface of the bush combing the branches stripping all of the berries and scraping the branches, damaging the plants.

Weygandt et al. U.S. Pat. No. 3,494,117 discloses a straddle-type picker having a pair of spaced drums supporting a plurality of fingers for contacting and dislodging the fruit from the bushes. The drums of Weygandt et al. are supported either on heavy coil springs or by spring arms. The drums are caused to vibrate through the use of rotating weights mounted within the drums. As the weights rotate simultaneously in the same direction, the drums move in an orbital manner. The orbital movement can cause thin branches to wrap around the fingers resulting in damage to the bushes.

In each of the aforementioned references, the entire shaker assemblies can be made to move laterally relative to the plants being harvested. In Rust, the shakers are manually movable while in Christie et al., the shakers are spring biased to extend toward the longitudinal centerline of the machine. In Weygandt et al. the shakers are mounted on powered movable arms. In each of the referenced systems, the shaker or picker has a tendency to comb the outer surface of each bush.

It is extremely important in harvesting blueberries that the proper amount of energy be applied to each bush so that only the ripened fruit is collected, leaving the green or not yet fully ripened fruit for picking at another time. It is also important that the bushes be protected from damage during the harvesting process. In the past, the rows of blueberry bushes being harvested were slapped by flailing arms or radically oscillating shaker drums which produced a complex series of motions in the hope of striking all of the berry bearing branches to pick the fruit. The erratic oscillations of the pickers caused not only unripe berries to be picked but also the bushes themselves to be damaged.

In accordance with the present invention, a straddle-type blueberry harvesting machine is disclosed which employs a pair of spaced shakers, each of which has its own independent source of vertical vibratory energy. The amount of energy applied to each of the shakers can be precisely controlled and is not dependent on or affected by the load placed upon the shaker. Regardless of the load placed upon each shaker, the same amount of energy is applied to each unit. As a shaker breaks free of heavy vegetation, it does not tend to race. It merely returns to its normal picking mode.

Each of the shakers is freely rotatable and will roll along a row of bushes at the same rate as the ground is traversed by the supporting frame. The fingers on the shakers are constrained to undergo a simple up and down motion which limits the tendency for branches to wrap about the fingers. In one embodiment of the present invention, the shakers are resiliently mounted on a separate pivotally mounted subframe which is supported by the main frame of the harvesting machine. The subframe is mounted above the longitudinal passage through which the bushes pass as the harvester straddles a row of bushes. The subframe supporting the shakers can be moved up and down to enable the rolling vibrating shakers to move up and down from branch to branch through a bush being harvested to gently dislodge the ripened berries from the bush. In another and more preferred embodiment, the shakers are resiliently attached to the main frame. In both embodiments of the harvesting machine, the lateral positions of the shakers are fixed. Each shaker has a plurality of spaced elongated picking fingers which penetrate deeply into each bush as the shakers freely rotate The picked fruit falls onto a plurality of movable catcher pans which form a substantially continuous floor under each bush as it moves through the machine, the catcher pans being movable by the bush.

A large volume of air is supplied under the catcher pans to deflect fruit which might fall through the opening. The picked fruit moves from the catcher pans onto a conveyor belt on each side of the machine. The conveyor belts have apertures therein and some of the air which blows under the catcher pans is directed through the apertures to clean the picked fruit. A secondary air supply on each side of the frame provides additional air to thoroughly clean the fruit to prepare it for washing and packaging without the need for additional cleaning.

FIG. 1 is a side elevational view of the blueberry harvesting machine;

FIG. 2 is a top plan view along the line II--II of FIG. 1, with the shaker assemblies removed so that the cleaning air blowers and conveyor belts can be seen;

FIG. 3 is a sectional view of the blueberry harvesting machine taken on the line III--III of FIG. 1, showing the location of the shaker assemblies, the blowers used in harvesting the blueberries, the catcher pans and the endless conveyor belts used to deliver harvested berries to containers at the rear of the machine;

FIG. 4 is an elevational schematic view showing the subframe used to support the shaker assemblies on the main frame;

FIG. 5 is an overhead view of the components used to resiliently attach a shaker assembly to a fixed frame;

FIG. 6 is a fragmented view of the bottom end of a shaker assembly showing the struts used to hold the shaker assembly in position; and

FIG. 7 is a fragmentary view showing the resilient supports for each shaker and associated driver on an embodiment of the harvesting machine employing a movable subframe.

Referring to FIGS. 1 and 2, the harvesting machine of the present invention is indicated generally by the number 10. The harvesting machine has an inverted U-shaped frame configuration having a left side 11 and a right side 13. The harvesting machine is a self-propelled motor vehicle having an engine 15 (FIG. 1) and four ground contacting wheels 17. The harvesting machine is controlled from a raised position 19 from which the operator can view the row of bushes and the individual bushes as they enter the machine. The inner and outer surfaces of the machine are covered with a smooth material, preferably sheet metal, to enable the machine to pass over a row of bushes being harvested and along adjacent rows without damaging the bushes. The leading edge portion 21 of each side of the machine is covered during operation to protect adjacent bushes and also to help direct extending branches of the bushes being harvested into the center portion of the machine.

As shown in FIG. 3, the bottom portion of the center of the harvesting machine is substantially closed by a plurality of pivotally mounted catcher pans 23. The catcher pans are supported by the frame of the harvesting machine at an inclined angle so that any fruit or berries falling on a pan will tend to roll downwardly and outwardly to the conveyor belts 27 where the fruit is transported to the rear of the machine where it is dropped into containers 29 (FIG. 2) supported on the shelf 31 which projects from each side of the rear of the harvesting machine.

In FIGS. 3 and 7, a pair of shakers, indicated by the number 40, are shown mounted on each side of the longitudinal centerline of the harvesting machine. Each shaker is supported in a collar 41. The bottom of each shaker has a collar 43 which is pivotally attached by struts 45 to the frame of the harvesting machine. This mounting at the top and bottom of each shaker 40 helps to limit the motion of the shaker to a simple vertical up and down movement. The absence of complex shaker movements tends to limit injury to the bushes.

Shaft 47 of each shaker assembly has a plurality of substantially rigid fingers or rods 49 projecting outwardly in a circular pattern about the central shaft. Rods 49 are supported by spaced hubs 50 attached to shaft 47. Hubs 50 can be attached to shaft 47 by any type of conventional fastener or by welding. Welding is preferred due to its simplicity and durability. Each shaker has an overall diameter of approximately 41 inches and is approximately 5 feet long with 18-20 sets of fingers spaced approximately three inches along the length of each shaft 47. Each shaker assembly is substantially lighter than the drum-type shakers previously used.

The shaker assemblies 40 (FIG. 8) are mounted in supports 41 and 43 so that the units can freely rotate as the row straddling harvesting machine passes over a row of blueberry bushes and the bushes pass between the shaker elements. The shakers will rotate at the same speed as the harvesting machine traverses the ground.

Referring to FIG. 6, the bottom portion of a shaker assembly 40 is shown. The collars 50, which support picking fingers 49, are made up of an upper collar 51 and a lower collar 53, each of which is preferably welded to center shaft 47. Between each of the upper and lower collars are mounted four sectors 55, each of which contain radially spaced grooves. When the sectors are stacked between the collars, the grooves align to provide a plurality of radially spaced sockets for receiving the ends of the rods 49. The collars 51 and 53 can be tightened by spaced nut and bolt fasteners 57 to compress the sectors onto the rods 49 to tightly hold the rods in place.

Each of the rods 49 is preferably made of fiberglass and is approximately twenty inches long and approximately one-half inch in diameter. In order to protect the bushes and berries from damage, the free end of each rod is slightly rounded to enable the rod to penetrate deeply into a bush without damage.

As previously discussed, shaft 47 of each shaker assembly is caused to move in a simple vertical up and down motion. In order to control and constrain the bottom of shaft 47, a sleeve 43 is mounted on the bottom of the shaft. Sleeve 43 contains a bearing assembly (not shown) to enable the shaker unit to freely rotate. A pair of spaced flanges 61, only one of which is shown, are welded to sleeve 43. A bolt and nut combination 63 provide a pivot point for a link 65 which is fastened to a pair of diverging struts 45. The remote ends of struts 45 are attached to pivotable links 67. The pivotable links are fastened to pivot pins 69. The pins 69 are attached to flanges 71 which are fastened to the frame of the harvesting machine. Sleeve 43 is free to move up and down in a vertical direction while erratic movements are prevented by pivotally mounted struts 45.

Each shaker 40 has a driver unit 80 which causes the shaker assembly to reciprocate vertically. Each driver unit 80 is an Ajax vibrating shaker drive which is manufactured by Renold Inc., Westfield, N.Y. Each driver unit contains a pair of counter-rotating weights. Driver units utilize the forces set up by rotating two weights in opposite directions. The two weights are mounted on shafts geared together and supported by anti-friction bearings in a totally enclosed housing. The centrifugal forces of the counter rotating weights combine at two points to produce a directional force. These points are where the weights are passing on the axis which is vertical (or perpendicular) to the foot mounting pad. When the driver is attached to a freely supported member, the forces generated will produce an amplitude of vibration at the running frequency. The weights in the driver unit are rotating in phase but in opposite directions so that the force applied when the weights pass at the top and bottom is delivered to the end of shaker assembly 40 in the form of a reciprocating motion.

A hydraulic motor 81 (FIG. 2) drives a shaft 83 upon which a pair of spaced pulleys 85 are mounted. Rubber drive belts 87 extend from each pulley 85 to a pulley 89 (FIG. 7) fixed to the drive shaft 91 of each driver unit 80. The rubber belts used can be simple V-belts with appropriately shaped pulleys or rubber timing belts having spaced teeth in cooperation with cogged pulleys. The operator of the harvesting machine can control the speed of hydraulic motor 81 and in turn the speed of rotation of driver units 80. The two driver units 80 can be operated either in phase with each other or out of phase with one shaker assembly 40 ascending while the adjacent shaker unit is descending.

Drive unit 80 is supported directly above each shaker unit 40 on a driver unit support platform 90. The drive unit 80 is on a platform 93 to which it is bolted by spaced bolts 95, referring to FIGS. 5 and 7. A pair of air bags 97 and 99 are supported on steel plates 101 and 103 which are welded to frame 105. Bolts 107 are used to hold the air bags in place on their respective supports. A side frame member 109 (FIG. 7) is connected between plate 93 and two plates 111 and 113. Plates 111 and 113 extend across the drive unit 80 to a second plate 109 (not shown) which is joined to the opposite end of plate 93. For clarity in FIG. 7, plate 109 is not shown on the left platform so that the air bags and their mountings can be seen. Air bag 97 is positioned between support plate 101 and cross plate 111 and is held in position by bolts 107. Air bag 99 is supported on plate 103 and is held below cross plate 113 by bolts 107. Air bags 97 and 99 are connected to a source of high pressure air so that the operator of the harvesting machine can inflate the bags to adjust the position of the shaker assemblies.

As indicated above, driver units 80 employ a pair of counter-rotating weights (not shown) which cause shaker assembly 40 to undergo vertical reciprocating motion. In order to preclude a twisting action being imposed on the shakers as the weights move outwardly in opposite directions, a pair of struts 115 and 117 are connected to the driver unit support platform 90. Struts 115 and 117 are fastened together by a brace 119 which spaces the attachment points of the two struts to frame 105. Struts 115 and 117 are preferably welded to brace 119 which is a length of two inch diameter steel tubing. A gusset plate 121 is fastened between strut 117 and brace 119 to resist the tendency for the shaker units 40 to be pushed backward as the harvesting machine advances over a row of bushes. The gusset plate could also be attached to strut 115 to provide a pulling force to resist movement of the shaker assembly. Likewise, two gusset plates can be used, if necessary, depending on the type of plants being harvested.

Strut 115 and attachment member 123 are each pivotally attached by fasteners 128, such as a combination of a bolt and nut, to a pair of spaced flanges 125 and 127 which are attached to fame 105. In order to reduce the amount of vibration transmitted to the frame, the end of strut 115 and attachment member 123 contain rubber blocks (not shown) through which fasteners 128 can pass. The second shaker assembly 40 is attached to frame 105 in substantially the same way using the mirror image of the connections.

In the preferred embodiment, driver units 80 and associated shaker assemblies are resiliently mounted directly on frame 105 of the harvesting machine. The operator of the machine can directly control the speed of rotation of the driver units and in turn the output power to move the shaker assemblies up and down sufficiently to harvest the blueberries.

In a second embodiment of the harvesting machine, the driver units and shaker assemblies are similarly attached to a subframe which is pivotally mounted in the center of the harvesting machine.

The subframe can be moved up and down by the machine operator to extend the area covered by the shaker assembly. Again, the operator can control the energy applied to the shaker assemblies and can, for example, use a very small amount of energy and gently move the shaker through an extended range. The operator can also apply a large amount of energy to the shaker assemblies and only move the subframe as the operator determines, depending on the particular harvesting conditions encountered.

Now referring to FIGS. 2 and 4, subframe 140, shaker assemblies 40 and driver units 80 can be seen mounted above the center portion of the harvesting machine. The frame of the harvesting machine is indicated generally by the number 105. Subframe 140 is pivotally mounted to longitudinal frame members 141 and 143 by a pair of pivot pins 145 and 147. As can best be seen in FIG. 4, subframe 140 can be moved upwardly and downwardly, as shown by arrow 150, by double acting hydraulic cylinders 151.

The frequency of the vibration of shaker units 40 can be determined by controlling the speed at which the motor 81 causes the counterweight driver units 80 to rotate. The driver units can cause the shaker assemblies to move up and down from approximately one to one and one-half inches, with the preferred range approximately three-quarters of an inch to one inch. Subframe 140 can raise approximately three inches so that the combination of the vibration and the movement of subframe 140 will enable picker fingers 49 to move gently as a unit up and down and from branch to branch of a bush to harvest the ripe berries. The driver of the harvesting machine can control the speed of movement of the machine across the ground, the frequency of the vibration applied to shaker assemblies 40, and the amplitude of the movement of subframe 140 relative to main frame 105. The driver can also adjust the overall height of frame 105 using conventional hydraulic cylinders (not shown). The driver, after a preliminary adjustment of the height of the frame, can then make a fine adjustment of the height of shaker assemblies 40 and fingers 49 by adjusting the air pressure applied to air bags 97 and 99 supporting the shaker units.

As best seen in FIG. 3, a blower assembly 160 is mounted in each side of the harvesting machine and directs its output air below catcher pans 23. The use of an air blower in the harvesting of blueberries is disclosed in U.S. Pat. application Ser. No. 07/605,580 filed Oct. 30, 1990, entitled BLUEBERRY HARVESTING MACHINE. The patent application was filed in the name of Donald Windemuller, a co-inventor of the present invention, and is incorporated herein by reference. In the preferred embodiment, the air is directed through the center of endless conveyor belt 27 in order to raise the bottom of the harvesting machine. The air can also be directed below the conveyor belt; however, this lowers the bottom of the machine and raises the possible incidence of ground contact and possible root damage to the bushes being harvested. The input air for the blower 160 is preferably brought into the sides of the machine through screened openings 162. Each blower assembly 160 is approximately four feet in length and sixteen inches in diameter and has a plurality of spaced, slightly concave, air moving veins for moving the air. The fans are preferably of the cross-throw type similar to fans used in wheat harvesting combines. While the cross-throw fan is preferred, the invention is not so limited. Other types of fans such as centrifugal and separate blades mounted on a hub can be used. Also, the fans can either push or pull the air.

Each fan 160 is preferably driven by a conventional hydraulic motor attached directly to the rotor. The fans can also be indirectly driven using rubber drive belts connected to remotely positioned hydraulic motors. By using direct drive for each blower on the harvesting machine, several sources of potential mechanical failure are eliminated, increasing the reliability of the blower assemblies.

In the operation of the harvesting machine, the driver approaches a row of blueberry bushes to be harvested and makes the initial height adjustment of the frame and any fine tuning necessary with the pressure applied to the air bags. The driver then activates the shaker units and blowers 160 and advances the harvesting machine to straddle the row of blueberry bushes. As the blueberry bushes enter the harvesting machine, the driver from his position above the row, can look down to see the action of the shaker fingers on the bushes and determine whether the frequency of the vibration should be increased or decreased and whether subframe 140 should be raised or lowered, if an embodiment of the harvesting machine with a subframe is being used, to enable the shaker assemblies to completely contact all of the fruit bearing branches of the bushes being straddled. As the shaker units dislodge the fruit, the fruit falls to the inclined floor formed by the pivotally mounted catcher pans and rolls to the side onto the conveyor belts. As the machine progresses, each blueberry bush opens an area of the catcher pans through which blueberries might fall and be lost on the ground. In order to prevent this loss, the fountain of air from blowers 160 flows upwardly through the opening in the catcher pans causing any blueberries which might tend to drop straight to the ground to be deflected to one side or the other of the harvesting machine. The asymmetric shape of the blueberry encourages this unstable flight. The combination of the motion of shaker assemblies 40 and the air blast from blowers 160 enables the harvesting machine to pick substantially all of the ripe berries from the blueberry bush without over-picking the bush, that is picking unripe berries or damaging the bush.

In FIG. 2, a pair of additional blowers 161 and 163 can be seen mounted on each side of the harvesting machine. Blowers 161 and 163 are similar to blower 160; however, they are substantially smaller in size. Output ducts 162 and 164 direct the air into a duct (not shown) below conveyors 27.

As the blueberries fall on catcher pans 23 (FIG. 3) they roll off into conveyor belts 27 on each side of the machine. The conveyor belt is made up of spaced plastic compartments 165 which have a plurality of apertures in the bottom. The conveyor belts are available from Intralox, Inc., Harahan, La.

A portion of the air supplied by blower 160 is allowed to blow up through the bottom of the conveyor belt at location 167 (FIG. 2). This air provides an initial cleaning for the berries removing leaves, twigs and other debris that might have fallen on conveyors 27. The conveyor then proceeds to station 169 where air from blowers 161 and 163 provide a second cleaning of the berries. Prior to the position where the conveyor turns and dumps the fruit into boxes 29, a third cleaning station 171 is provided. The three separate cleaning stations thoroughly remove all foreign material from the berries enabling the berries to be washed and packaged or quick frozen without further cleaning and handling, substantially reducing the amount of labor involved in handling and cleaning the picked berries.

Though the invention has been described with respect to a specific preferred embodiment thereof, many variations and modifications will become apparent to those skilled in the art. It is therefore the intention that the appended claims be interpreted as broadly as possible in view of the prior art to include all such variations and modifications.