Seed packet filling and closing machine

A machine for filling and closing seed packets has a conveyor system which includes first and conveyors, when continuously advance a succession of preformed seed packets. Packets are filled from a continuously rotating funnel wheel which receives seed from a vibratory feeder as the packets are advanced by the first conveyor. The second conveyor receives packets from the first conveyor and applies sealing pressure to the closing flaps on the packets as the packets are further advanced.

BACKGROUND OF INVENTION
 This invention relates in general to packaging apparatus and deals more
 particularly with an improved seed packaging machine for filling and
 closing preformed seed packets.
 Such seed packaging machines of the aforementioned type as have been
 heretofore available are generally complex mechanisms designed for low
 speed operation, operate with intermittent motion, and have large numbers
 of moving parts. Such machines are generally expensive to produce, operate
 and maintain, are subject to heavy wear, and usually require frequent
 adjustment, which adds substantially to machine operating cost.
 Accordingly, it is the general aim of the present invention to provide an
 improved seed packet filling and closing machine which may be produced at
 relatively low cost, and which is designed for continuous high speed,
 maintenance free operation. It is a further aim of the invention to
 provide a machine which may be readily adjusted by an operator having
 ordinary skill to accommodate frequent changes in seed feeding
 requirements with minimal machine downtime.
 SUMMARY OF THE INVENTION
 In accordance with the present invention an apparatus is provided for
 filling and closing preformed seed packets which have front and rear
 panels connected together along bottom and side edges, an upwardly open
 mouth and an upwardly extending closure flap connected to an upper edge of
 one of the panels. The apparatus comprises a supply magazine for
 containing a quantity of packets, packet feeding means for withdrawing
 each successive packet from the supply magazine and disposing it in a
 pick-up position, first conveying means for engaging each successive
 packet at the pick-up position, gripping an associated lower portion of
 the packet, and continuously advancing the packet along a predetermined
 path to and through a packet filling station. A packet opening means
 mounted in fixed position along the predetermined path opens the packet as
 the packet advances along the predetermined path to the filling station.
 Seed dispensing means at the filling station load a predetermined quantity
 of seed into the packet through the mouth thereof as the packet is
 advanced along the predetermined path through the filling station. A
 packet closing means is provided for closing the closure flap as the
 packet is further advanced along the predetermined path from the packet
 filling station.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENT AND METHOD
 In the drawings and in the description which follows the present invention
 is illustrated and described with reference to a seed packet filling and
 closing machine embodying the invention and indicated generally by the
 numeral 10. The illustrated machine 10 is particularly adapted to fill and
 close standard preformed 31/4.times.41/2 seed packets. However, modified
 versions of the machine may be provided to accommodate seed packets of
 other sizes.
 The machine 10 shown in FIGS. 1 and 4 generally comprises a frame,
 indicated generally at 12, which supports a conveyor system. The conveyor
 system includes first and second conveyors generally indicated at 14 and
 16, respectively, which cooperate to continuously move a succession of
 preformed seed packets along a predetermined path to and through
 successive work stations where packet filling, closing and marking
 operations are performed on the advancing packets. More specifically, the
 first conveyor 14 receives a succession of upwardly open seed packets at a
 packet feeding station 18, grips a lower portion of each successive seed
 packet and advances the packet to and through a packet filling station 20
 where a continuously moving seed distributor 22 deposits a predetermined
 quantity of seed in the packet through the upwardly open mouth of the
 packet. The moving packet is further advanced by the first conveyor 14
 from the packet filling station 20 to a closing station 24 where a closure
 flap on the packet is folded from an open to a closed position and sealed
 in the latter position. The second conveyor 16 receives the filled and
 closed packet from the first conveyor 14, grips an upper marginal portion
 of the moving packet, and urges the closure flap toward and holds the flap
 in sealed position while conveying the packet along a further portion of
 the predetermined path to a marking station 26 where code information or
 other indicia is or may be imprinted on the packet, after which the packet
 is ejected from the machine at a discharge station 28, all of which will
 be hereinafter more fully described. However, before describing the
 machine 10 in further detail, a preformed seed packet used with the
 machine will be briefly considered to aid in a further understanding of
 the machine and the manner in which the packet cooperates with the
 machine.
 The construction of the seed packet may vary; however, a typical preformed
 seed packet used with the machine of the present invention and shown in
 FIGS. 5 and 6 essentially comprises a substantially flat paper envelope
 formed from a unitary blank and indicated generally by the letter P. The
 packet P has front and rear panels designated, respectively, by the
 letters F and R and joined together along a bottom edge B and side edges
 S, S'. The front and rear panels F and R cooperate to define an upwardly
 open mouth M. A closure flap C connected to an upper edge of the front
 panel F extends upwardly from the front panel when the packet is in an
 open condition for use with the machine 10, as hereinafter further
 discussed. The closure flap C is adapted to be folded from the aforesaid
 open position to a closed position wherein it overlies an upper portion of
 the rear panel R and, for this reason, the closure flap C is preferably
 connected to the front panel F along a preformed fold or score line
 indicated by the letter L. Although the presence of a fold line on the
 packet is not essential to the operation of the machine 10, the fold line
 is desirable, because it aids in assuring proper packet closure.
 Considering now the illustrated machine 10 in further detail, and referring
 first particularly to FIGS. 1 and 4, the frame 12 essentially comprises a
 table-like structure and has a top or horizontal base plate 30. The
 conveyor system which includes the first and second conveyers 14 and 16 is
 mounted above the base plate 30 and comprises a plurality of endless
 conveyor chains supported by sprockets mounted on vertically upwardly
 extending shafts. The first conveyor 14 receives a succession of empty
 preformed seed packets P, P at the packet feeding station 18 and conveys
 each packet along an initial portion of a predetermined path through the
 machine 10. The first conveyor includes vertically spaced apart upper and
 lower conveyor chains disposed in horizontal planes and respectively
 indicated at 32 and 34. The lower conveyor chain 34 is driven by a main
 drive sprocket 36 keyed to a first or main drive shaft 38 which extends
 upwardly through the base plate. The lower end of the main drive shaft 38
 is coupled by a friction clutch 40 to a DC drive motor 42 mounted on the
 frame 12 below the base plate 30 and near the front and the left hand or
 discharge end of the machine 10, as shown in FIG. 1.
 The lower conveyor chain 34 drives a second drive sprocket 44 keyed to a
 second drive shaft 46, located near the right hand or input end of the
 machine 10, and is further supported by an idler sprocket and a pivotally
 mounted chain tensioning sprocket 50 biased toward a tensioning condition
 relative to the conveyor chain 34. The lower conveyor chain 34 carries a
 plurality of generally V-shaped flights 52,52 and generally L-shaped jaws
 54, 54 arranged in spaced apart alternate series along the conveyor chain
 for engaging seed packets, as will be herein after further described.
 The first conveyor 14 further includes an endless backup conveyor chain 56,
 best shown in FIGS. 2 and 3 and disposed rearwardly of and generally
 within a horizontal plane of the lower conveyor chain 34. The backup chain
 56 is supported by a plurality of sprockets and travels along the frontal
 surface of a vertically disposed backup wall 58 mounted in fixed position
 on the base plate 30 immediately rearward of the lower conveyor chain 34.
 The backup chain 56 carries a plurality of L-shaped jaws 54', 54' for
 cooperating in generally complementary interlocking and gripping relation
 with the opposing L-shaped jaws 54, 54 on the lower conveyor chain 34. A
 spring biased pressure bar 60 (FIG. 8) mounted on the base plate 30
 inwardly of the rear run of the lower conveyor chain 34 biases a portion
 of the lower conveyor chain toward the backup wall 58 whereby the gripping
 jaws 54, 54 on the lower conveyor chain 34 are biased toward complementary
 gripping engagement with associated opposing gripping jaws 54', 54' on the
 backup conveyor chain 56 generally along the entire length of the pressure
 bar 60.
 The upper conveyor chain 32 is supported by a plurality of sprockets
 mounted on upper portions of the shafts which carry the sprockets
 supporting the lower conveyor chain 34. The upper conveyor chain 32 is a
 near mirror image of the lower conveyor chain 34 and carries a series of
 flights 52', 52', each flight 52' being vertically aligned with an
 associated flight 52 on the lower conveyor chain. However, unlike the
 lower conveyor chain 34, the upper conveyor chain 32 does not have
 gripping jaws. The upper conveyor chain 32 is driven by the lower conveyor
 chain 34 and more specifically by the second drive sprocket 44 and second
 drive shaft 46. A third drive sprocket 61 is mounted in fixed position on
 and angularly adjustable relative to the second drive shaft 46, to permit
 adjustment of the upper conveyor chain 32 relative to the lower conveyor
 chain 34 to bring each flight 52' on the upper chain into vertical
 alignment with an associated flight 52 on the lower conveyor chain. For
 this reason a sprocket 63 which supports the upper conveyor chain 34 on
 the main drive shaft 38 is angularly movable relative to the main drive
 shaft.
 A horizontally elongated support rail 62 which defines a horizontally
 disposed and upwardly facing packet supporting surface 64 is located below
 the lower conveyor chain 34 and the backup conveyor chain 56 as best shown
 in FIG. 7 and 8. The support rail is mounted on the backup wall 58 for
 vertical adjustment relative to the wall to adjust the vertical position
 of the packet supporting surface 64 relative to the upper and lower
 conveyor chains 32 and 34 and the backup conveyor chain 56.
 Referring now particularly to FIGS. 1 and 2, the second conveyor 16 is
 mounted on and below a horizontal carrier plate 66 supported on stanchions
 (one shown in FIG. 1) above the base plate 30 and at a level above the
 level of the horizontally disposed first conveyor 14. The infeed end of
 the second conveyor 16 is disposed in slightly overlapping relation to the
 discharge end of the first conveyor 14, which discharge end is at the
 return end of the backup conveyor chain 56. The second conveyor 16
 cooperates with the first conveyor 14 to define the predetermined path of
 packets P, P through the machine 10. More specifically, the second
 conveyor 16 is adapted to receive each successive packet P from the first
 conveyor 14, grip an upper portion of the packet at a position along its
 closed closure flap C and further advance the packet along a final portion
 of the predetermined path through the machine 10. The second conveyor 16
 generally comprises an endless second conveyor chain 68 supported on the
 underside of the carrier plate 66 by a plurality of sprockets, which
 include idler, tension and drive sprockets, and travels in a generally
 rectangular path. The second conveyor 16 is driven in timed relation to
 the first conveyor by a drive sprocket 69 mounted on the main drive shaft
 38 and coupled by a drive chain 71 to a driven shaft 73 and sprocket 75
 associated with the second conveyor 16. The second conveyor chain 68
 carries a series of spaced apart groups of discrete pressure pads 70, 70'
 for engaging each filled, closed and sealed seed packet along its closure
 flap C as the packet is further advanced by the second conveyor. A typical
 group of pressure pads shown in FIG. 14 includes 5 discrete pads, the
 outermost pads 70', 70' of the group having chamfered lower corners. A
 linear array of closely spaced rollers 72, 72 journalled on the carrier
 plate 66 for rotation about vertical axes are disposed adjacent the inner
 side of the second conveyor chain 68 along the rear run of the chain and
 provide backup for the second conveyor chain along a substantial portion
 of its rear run. The second conveyor 16 further includes an endless
 elastomeric belt 74 supported by crowned rollers 77, 77 to run in
 engagement with groups of pressure pads 70, 70' as the pressure pads
 travel along the rear run of the second conveyor chain 68. The elastomeric
 belt 74 is spring biased in a forward direction and toward engagement with
 the pressure pads 70, 70' carried by the rear run of the second conveyor
 chain 68, substantially as shown in FIG. 2. Thus, the overlapping first
 and second conveyors 14 and 16 which comprise the conveyor system define
 first and second portions of a predetermined path along which seed packets
 P, P are conveyed through the machine 10.
 Preformed seed packets P, P contained in a supply magazine 76 at the packet
 feeding station 18 are successively withdrawn from the magazine by an
 electrically controlled pneumatically operated vacuum feeding device
 indicated generally at 78 which removes each successive packet P from the
 supply magazine 76, positions and releases the packet at a pick-up
 location in alignment with a nip at the in-feed end of the first conveyor
 14 and in the path of upper and lower flights 52', 52 carried by the upper
 and lower conveyor chains 32 and 34. The piston/cylinder operated vacuum
 feeding device 78 is operated by a programmable logic controller (PLC) 80,
 shown in FIG. 1, in response to signals received from a rotary encoder 82
 located below the base plate 30 and driven in timed relation to the
 conveyor system by the drive shaft 46, which drives the upper conveyor
 chain 32.
 Seed is fed into each packet P from the seed distributor 22 which
 preferably comprises a rotary turret type distributor or funnel wheel
 journalled for rotation about a horizontal axis above the first conveyor
 14. The presently preferred funnel wheel 22 (FIGS. 7 and 8) comprises a
 star-shaped wheel having coaxial circular front and rear walls and a
 circumaxial series of radially outwardly projecting funnels 84, 84 which
 converge radially outwardly to seed discharge openings 86, 86. Each funnel
 has a radially outwardly extending tab 87 at its outer or discharge end.
 The inner end of each funnel defines a seed receiving mouth 88 immediately
 adjacent and forming a junction with the mouth of the next successive
 funnel 84 in the circumaxial series. The rear wall of the funnel wheel 22
 is mounted on and in coaxial alignment with an axially horizontal drive
 shaft 89 connected by bevel gears to a vertically oriented drive shaft 90
 driven by a drive sprocket 92 located below the base plate 30. A drive
 chain 94 located below the base plate and engaged with the sprocket 92 and
 a drive sprocket 96 on the main drive shaft 38 (FIG. 1) drives the funnel
 wheel 22 in timed relation to the operation of the conveyor system. The
 drive chain 94 also engages a sprocket which drives the backup chain 56 in
 timed relation to the lower conveyor chain 34.
 Seed is fed into the seed distributor or funnel wheel 22 from a vibratory
 feeder 99 of a well known type having a cylindrical feeder bowl including
 a spiral track and associated gates which direct seed from the bowl to and
 along the track into a chute 101 disposed between the vibratory feeder 99
 and a circular seed receiving opening 103 in the circular front wall of
 the funnel wheel 22 as shown in FIG. 8. A lightweight flexible flap 105 at
 the discharge end of the chute 101 aids in controlling seed discharge from
 the chute into the funnel wheel 22.
 The illustrated machine 10 also includes a packet opening device 98 (FIG.
 7) for opening the mouth of each packet P to prepare the packet to receive
 seed from the funnel wheel. The presently preferred packet opening device
 comprises a first air supply tube 100 for directing a blast of air under
 pressure, received from a pressurized air supply source (not shown),
 downwardly and toward the mouth of each packet as the packet is advanced
 toward the funnel wheel 22 by the first conveyor 14.
 A second air supply tube is preferably provided for directing a blast of
 air into each seed packet P while the packet is being filled by the funnel
 wheel, for a reason which will be hereinafter further discussed. The
 second air supply tube is shown in FIGS. 7 and 8 and indicated by the
 numeral 102. The air supply tube 102 is mounted in fixed position relative
 to the base plate 30, connected to a pressurized air supply source (not
 shown) and is or may be controlled by the PLC 80 to operate in timed
 relation to the seed feeding cycle of the funnel wheel 22 in response to
 signals from the rotary encoder 82.
 The packet closing station 24 (FIG. 4) is located along the portion of the
 predetermined path defined by the first conveyor 14 and between the funnel
 wheel 22 and the second conveyor 16 for closing each filled packet as it
 is further advanced by the first conveyor 14. The presently preferred
 closure flap closing and sealing mechanism, located at the closing station
 24, includes a glue applicator indicated generally at 104 for applying a
 stripe of liquid glue to the closure flap C of each packet as the closure
 flap passes through the flap closing station 24. The illustrated
 applicator 104, shown in FIGS. 4 and 9, has a driven glue applicator wheel
 106 which receives liquid glue from a reservoir 108 and transfers the glue
 to the closure flap C of each advancing seed packet P. Referring
 particularly to FIG. 4 drive sprockets engaged with the upper and lower
 conveyor chains 32 and 34 drive a gear train which, in turn, rotates the
 glue applicator wheel 106 in timed relation to the operation of the first
 conveyor 14 so that the linear speed of the circumferential glue
 applicator surface of the applicator wheel 106 substantially equals the
 linear speed of the advancing conveyor 14. As the moving packet leaves the
 glue applicator 104 it encounters a plow 112 of a generally conventional
 type which engages the upwardly extending closure flap C to which glue has
 been applied and folds the closure flap in a forward and downward
 direction to a closed and sealed position in overlying engagement with the
 packet rear panel R.
 After leaving the closing station 24, the upper portion of the advancing
 closed packet P, which includes the closed closure flap C, enters the
 second conveyor 16 at a nip formed between a group of pressure pads 70,
 70' carried by the rear run of the conveyor chain 68 and the elastomeric
 belt 74. The jaws 54, 54' on the first conveyor 14 separate releasing the
 packet P from the first conveyor 14 as the packet enters the nip of the
 second conveyor 16. As each filled and closed packet is advanced by the
 second conveyor 16 an associated group of pressure pads 70, 70' cooperate
 with the elastomeric belt 74 to apply sealing pressure to the packet
 closure flap C. The applied pressure may cause some glue to be extruded
 near the opposite ends of the closure flap; however, the chamfers on the
 end pads 70', 70' of the group, best shown in FIG. 14, provide end
 clearance to enable the pressure pads to avoid glue contamination.
 The effective length of the second conveyor 16 is such that the portion of
 the conveyor which is operative to convey each packet allows time for the
 glue to dry while the closure flap is held in its sealed position by the
 conveyor. As each completed filled and sealed seed packet P approaches the
 discharge end of the second conveyor 16 the packet passes through the
 marking station 26 where a rotary printing mechanism 116 which operates in
 timed relation with the conveyor system applies desired indicia to the
 closed package. Such indicia may, for example, comprise a date code or lot
 number.
 The rotary printing mechanism 116, shown somewhat schematically in FIG. 11,
 essentially comprises a printing cylinder 118 which carries a rubber
 printing die segment 120. The illustrated printing cylinder 118 is
 supported on a vertical drive shaft 122 journalled on the carrier plate 66
 and may receive ink from any appropriate source, such as an inking pad
 indicated at 124. The illustrated printing cylinder is driven in timed
 relation with the second conveyor 16 by a timing belt 126 drivingly
 connected to the upper end of the main drive shaft 38. It will now be
 apparent that the marking station 26 may be located at any convenient
 position on the machine; however, it is preferably located near the
 discharge end of the machine to avoid risk of ink being smeared on the
 packets as the packets are advanced through the various work stations by
 the conveyor system.
 As each filled, closed, and marked seed packet leaves the conveyor system
 at the discharge end of the second conveyor 16, it enters the discharge
 station 28 where a crank-operated slide mechanism, indicated generally at
 128 and which carries a movable pusher 130, engages the trailing side edge
 S' of the packet to separate the packet from the conveyor flights. The
 crank-operated slide mechanism 128 operates continuously with a
 reciprocating motion. The pusher 130 carried by the slide mechanism is an
 electrically-controlled pneumatically-operated device which operates in
 response to signals from the PLC 80 to move the pusher 130, which travels
 with the slide, into and out of alignment with the trailing side edge S'
 of each successive packet as it leaves the second conveyor 16. The pusher
 130 pushes the packet into the path of an electrically-controlled and
 pneumatically-operated ejector 132 which also operates in response to
 signals from the PLC and abruptly changes the direction of packet
 movement, causing each successive packet to move onto an
 independently-driven belt conveyor 134 located adjacent the end of the
 machine 10 as it leaves the machine. The belt conveyor 134 extends in a
 direction normal to the predetermined path of the packets through the
 machine 10 and carries each packet away from the machine and to an
 operator station (not shown) where the completed packets are or may be
 collected for packaging and shipment.
 Preparatory to operating the machine 10, a quantity of preformed seed
 packages P, P are loaded into the supply magazine 76. A manually operable
 start button (not shown) energizes the DC drive motor 42 which places the
 conveyor system in operation. The programmable logic controller (PCL) 80
 responds to a signal from the rotary encoder 82 to operate an air valve
 which controls the vacuum pick-up device 78 causing the pick-up device to
 withdraw a packet P from the supply magazine 76 and move the packet to and
 release it at the pick-up location at the in feed end of the first
 conveyor 14 where upper and lower flights 52, 52' on the upper and lower
 chains of the first conveyor 14 engage vertically spaced apart portions of
 the packet trailing side edge S'. As the packet P is advanced by the
 flights with its bottom edge B in sliding engagement with the packet
 supporting surface 64 a pair of opposing jaws 54, 54' carried by the lower
 conveyor chain 34 and its opposing backup conveyor chain 56 close on the
 packet and grip the packet at a predetermined position near its bottom B
 and leading side edge S. As the upwardly open preformed packet P is
 advanced by the first conveyor 14 it passes under the first air supply
 tube 100 which directs a blast of air under pressure toward and into the
 packet mouth M whereby the mouth is opened. The air control valve
 associated with the fist air supply tube 100 may be set to deliver a
 continuous blast of air or may be controlled by the PLC in timed relation
 to movement of the conveyor system to deliver a blast of air only when a
 packet is properly positioned to receive the air blast. As the packet, in
 opened mouth condition, approaches the funnel wheel 22 a tab 87 on one of
 the funnels enters the open mouth M and guides the funnel into said
 feeding position relative to the mouth. The tab also controls the packet
 closing flap C maintaining the flap in its upstanding position.
 Upon initiation of the machine starting cycle the vibratory feeder
 commences to continuously feed seed into the funnel wheel 22 at a
 predetermined rate set by a manually controlled regulator (not shown). The
 seed feed rate may be regulated by the machine operator independent of
 other machine control functions. The required feed rate is generally
 determined by the type of seed to be packaged. As each funnel 84 moves
 angularly about the axis of the funnel wheel 22 and into, through and out
 of loading position relative to a seed packet P moving thereunder a
 generally predetermined quantity of seed is discharged from the funnel
 wheel and into the packet. It has been found that a reasonably accurate
 positive packaging tolerance can be maintained by establishing properly
 regulated settings for the vibratory feeder control regulator thereby
 avoiding the need for expensive weighing or measuring devices for
 controlling seed delivery. The presently preferred machine employs a
 funnel wheel which has 10 feeding funnels. It has been found that the
 angular movement of the funnel wheel in timed relation with the advancing
 movement of the conveyor system assures interruption of the flow of seed
 from each feeding funnel in the interval during which each packet is being
 moved into or out of seed receiving position relative to a funnel 84 by
 the advancing movement of the conveyor system. By regulating the feed rate
 of the vibratory feeder manually and independently of the operation of the
 machine, a trained machine operator may rapidly and accurately change the
 seed feeding rate so that changeover from packaging one type of seed to
 another may be accomplished with minimal machine down time. As seed is
 being discharged into a packet P from an associated funnel a blast of air
 is simultaneously directed into the open seed packet from the second air
 supply tube 102. The air flow into the packet aids in the flow of seed
 into the packet and toward the packet bottom and also assures that seed
 will not become lodged in an upper portion of a packet near a packet side
 edge which could interfere with proper package closure.
 In accordance with presently preferred practice, liquid adhesive is applied
 to the envelope closing flap at the closing station 24 in the manner
 previously described. However, it should be understood that other closure
 flap sealing arrangements are possible and are contemplated within the
 scope of the present invention. Thus, for example, dry adhesive may be
 carried by a preformed envelope flap and activated at the closing station
 by the application of moisture using any appropriate applicator, including
 an applicator wheel of the aforedescribed general type. A spray-on
 adhesive may be applied to the closure flap at the closing station and
 such arrangement is also contemplated within the scope of the present
 invention.
 After the closing flap C has been prepared for sealing the flap is moved to
 its closed position. A conventional plow is preferably employed to perform
 the flap closing operation, because a plow provides both positive and
 economical means for performing this function. The second conveyor applies
 sealing pressure to the closure flap after the flap has moved to its
 closed position relative to the packet. The marking or printing mechanism
 associated with the second conveyor 16 completes the packaging operation
 by applying such code information to each packet as may be necessary. The
 PLC controls the package ejector which changes the direction of packet
 movement as the completed packet leaves the machine and enables provision
 of a machine of minimal length, thereby minimizing the machine footprint
 to conserve valuable floor space.
 In addition to the features herein before described, the machine 10 may
 include other control functions. Thus, for example, a sensing device, such
 as a photoelectric cell, for example, may be employed for detecting an
 empty supply magazine condition and interrupting operation of the machine
 when such condition occurs. A sensing device of a similar type may also be
 provided to detect interruption of the ordinary flow of packets to the
 seed filling station and shut down the machine if such interruption should
 occur. A sensing device associated with the PLC may also be employed to
 monitor the ejection of packets from the machine.