Tag insertion device for a bag tyer

TECHNICAL FIELD

The invention relates to a tag attachment accessory to a machine for wrapping a ribbon around the gathered neck of a bag and twisting the ribbon for closing and sealing the neck of the flexible bag.

BACKGROUND OF INVENTION

U.S. Pat. No. 3,138,904 entitled “METHOD AND APPARATUS FOR TYING PACKAGES AND WRAPPING MATERIALS;” U.S. Pat. No. 3,059,670 entitled “WIRE TWISTING TOOL;” U.S. Pat. No. 3,919,829 entitled “APPARATUS FOR TYING PACKAGES AND WRAPPING MATERIALS;” U.S. Pat. No. 4,856,258 entitled “WIRE TYING DEVICE;” and U.S. Pat. No. 5,483,134 entitled “RIBBON SENSING DEVICE FOR BAG TYER” disclose apparatus used for closing a plastic bag by attaching and twisting a wire-like ribbon about the neck of the bag.

Bag tying devices of the type disclosed in the aforementioned patents are commercially available from Burford Corporation of Maysville, Okla. The tying devices are generally constructed to receive packages such as loaves of bread at speeds of for example one hundred (100) packages per minute.

SUMMARY OF INVENTION

The bag neck tying device disclosed herein incorporates a bag neck gathering mechanism comprising motor driven gathering belts for moving a bag neck along a path in a plane into engagement with a bag stop controlled by an electric brake positioned adjacent a ribbon holder-shear assembly which holds the free end of a ribbon of tie material. A motor driven needle wraps the strand of the tie material around the gathered neck of the bag, and a motor driven twister hook assembly engages the free end and the running end of the ribbon adjacent the gathered neck for twisting the ribbon.

Independently controlled bi-directional, brush type servomotors are mounted in the separate subassemblies of the tying device. Each of the servomotors is controlled by a solid state DC motor controller in a closed loop feedback system under the control of a multichannel microcontroller which precisely starts, controls and stops each of the servomotors in a pre-assigned sequence for each cycle of the tying apparatus.

The tag attachment device is a retrofit option to the standard servo-tyer. The tag attachment device can be mounted on the tyer by removing the cover with the two screws, using a drill template to add some additional holes for the air cylinder, removing the gathering belt and adding a pivot point. The gathering belt is replaced and an air cylinder is installed. The tag attachment device assembly itself bolts onto the existing servo-tyer bracket. The only electrical interface between the tag attachment device system and the servo-tyer is one unused contact in the switch that triggers the servo-tyer. A spool holder for a supply of tags and the tag attachment device are then mounted on the frame.

DESCRIPTION OF THE DRAWINGS

Drawings of a preferred embodiment of the invention are annexed hereto so that the invention may be better and more fully understood, in which:

FIG. 1

is a perspective view illustrating the front of the bag neck tying device;

FIG. 2

is a diagrammatic front elevational view;

FIG. 3

is a diagrammatic rear elevational view;

FIG. 4

is an end view looking generally in the direction of the arrows along line

4

—

4

in

FIG. 2

;

FIG. 5

is a diagrammatic end view illustrating the discharge end of the bag neck tying device, looking in the direction of the arrows along line

5

—

5

in

FIG. 2

;

FIG. 6

is a top plan view, looking in the direction of the arrows along line

6

—

6

in

FIG. 2

, parts being broken away to more clearly illustrate the details of construction;

FIG. 7

is a wiring diagram of the closed loop microcomputer controlled control system;

FIG. 8

is an enlarged elevational view similar to

FIG. 2

;

FIG. 9

is a diagrammatic elevational view of the tag attachment device;

FIG. 10

is a fragmentary elevational view of a strip of tags;

FIG. 11

is a diagrammatic elevational view similar to

FIG. 9

of a second embodiment;

FIG. 12

is an end view of the apparatus illustrated in

FIG. 11

; and

FIG. 13

is an enlarged diagrammatic view of a solenoid actuated feed roller.

Numeral references are employed to designate like parts throughout the various Figures of the drawing.

DESCRIPTION OF A PREFERRED EMBODIMENT

The wire tying device, generally designated by the numeral

10

, in

FIGS. 1 and 2

of the drawing is mounted adjacent the side of a conveyor

300

of the type disclosed in U.S. Pat. No. 5,483,134 to Jimmy R. Frazier, John D. Richardson and Greg P. Coxsey entitled “RIBBON SENSING DEVICE FOR BAG TYER,” the disclosure of which is incorporated herein by reference in its entirety for all purposes, for tying a flexible bag by attaching and twisting a wire-like ribbon about the neck of the bag. Conveyor

300

carries for example, loaves of bread to, through and out of wire tying device

10

in rapid succession. Conveyor

300

is well known to persons skilled in the art and further description thereof is not deemed necessary except in connection with the drive mechanism as will be hereinafter more fully explained. It should be appreciated that other and further structures may form the conveyor. Improvements is a tag attachment device

100

expand the capabilities of the servo-tyer of the type disclosed in U.S. Pat. No. 5,483,134.

Referring to

FIGS. 1 and 2

of the drawing, the numeral

20

generally designates a bag gathering apparatus for moving a bag B along a path

12

to a position adjacent a needle assembly

40

, a twister hook assembly

50

and a holder-shear assembly

60

. As will be hereinafter more fully explained, the free end of a ribbon of wire-like material

15

is gripped in holder-shear assembly

60

. The neck of the bag moves through a slot

122

between upper face plate

16

and lower face plate

17

for drawing the bag B to a controlled tension about the contents thereof. Needle assembly

40

wraps the ribbon

15

of the wire-like material about the gathered neck of the bag and twister hook

50

is actuated for twisting a portion of the wire-like material about the neck of the bag B. It should be noted that the ribbon of material

15

may be constructed of wire enclosed in paper or plastic or it may comprise a ribbon of plastic or any other material. The strand of ribbon

15

extends around one or more pulleys

41

,

41

a

and

41

b

mounted on shafts

41

a

from a spool of tie material (not shown).

The mounting for the spool is similar to that disclosed in U.S. Pat. No. 3,919,829 entitled “APPARATUS FOR TYING PACKAGES AND WRAPPING MATERIALS”, the disclosure of which is incorporated herein by reference in its entirety for all purposes. However, it will be noted that the spool of tie material is mounted on a shaft and tie material

15

is fed from the spool and is routed around rollers

41

b,

41

a

and

41

, around needle roller

44

and the end of the ribbon

15

is gripped in the holder-shear assembly

60

, as best illustrated in

FIGS. 1 and 7

of the drawing. The spool is mounted on a shaft engaged by a brake (not shown). As needle

42

forms a loop of tie material around the gathered neck of a bag, the force of inertia and force exerted by the brake cause the spool to remain stationary momentarily as a crank arm, on which roller

41

a

is mounted, is rotated in a clockwise direction as illustrated in

FIG. 2

of the drawing.

As will be hereinafter more fully explained, one of the pulleys

41

,

41

a

or

41

b

is preferably equipped with a sensor device which is capable of calculating the amount of ribbon

15

dispensed from the spool. The sensor apparatus determines whether or not a bag neck is present. As needle

41

moves from the full outline position illustrated in

FIG. 2

to the dashed outline position, if a bag neck is not positioned in the path of the ribbon, the cycle of operation will be interrupted so that the holder-shear assembly

60

will not be actuated and the twister hook assembly

50

will not rotate. This prevents actuation of the holder-shear assembly which would have resulted in the ribbon being dropped or released if a bag neck was not present.

The frame of the bag tying device may assume many configurations. In the illustrated embodiment upper and lower face plates

16

and

17

are supported on forward edges of vertically extending end plates

18

and

19

having slots formed therein to permit passage of a bag neck. A horizontal mounting plate

19

a

extends between lower portions of end plates

18

and

19

and a vertical mounting plate

16

a

extends outwardly from end plate

18

.

A motor M

1

, having an encoder E

1

mounted the rear end of motor M

1

, is mounted on an upper portion of the vertical mounting plate

16

a

for driving the gathering assembly

20

. A motor M

2

, having an encoder E

2

mounted the rear end and a gear box

46

mounted on the front end of motor M

2

, is mounted on an upper portion of the rear surface of face plate

16

for driving the needle assembly

40

. A motor M

3

, having an encoder E

3

mounted the rear end of motor M

3

, is mounted vertically on horizontally extending mounting plate

19

a

for driving the twister hook assembly

50

. A motor M

4

, having an encoder E

4

mounted the rear end of motor M

4

, is mounted on a lower portion of end plate

18

, and in the illustrated embodiment extends below motor M

2

, for driving the holder-shear assembly

60

.

Referring to

FIGS. 1-5

of the drawing, bag neck gathering apparatus

20

comprises, in a preferred embodiment of the invention, an upper gathering belt

22

routed around a driven pulley

24

and idler pulleys

26

,

27

and

28

. The bag neck gathering mechanism

20

further comprises a lower gathering belt

32

routed around a driven pulley

34

and idler pulleys

36

,

37

and

38

. As best illustrated in

FIG. 1

of the drawing, the portion

29

of the upper gathering belt

22

, extending between idler pulleys

27

and

28

, is substantially parallel and closely spaced relative to the portion

39

of the lower gathering belt

32

which extends between driven pulley

34

and idler pulley

36

. In the illustrated embodiment, gathering belts

22

and

32

move a bag neck along path

12

in a plane P as illustrated in

FIG. 2. A

pressure pad

21

, resiliently urged upwardly by springs

21

a

and

21

b

acting through bell cranks, maintains belts

22

and

32

in frictional engagement with the neck of a bag or other material to be tied.

As best illustrated in

FIGS. 3 and 5

of the drawing, driven shaft

25

, having driven pulley

24

mounted on one end, has a pulley

23

mounted on its opposite end. Driven shaft

35

, having driven pulley

34

mounted on one end, has a pulley

33

mounted on its opposite end. A pulley

30

mounted on the drive shaft of motor M

1

drives pulleys

23

and

33

through a belt

31

such that driven pulley

24

rotates in a clockwise direction while driven pulley

34

rotates in a counter-clockwise direction, as viewed in

FIG. 2

of the drawing. Belt guards

16

a

and

16

b

and

17

a

preferably extend between the gathering belts and products on the conveyor, as illustrated in FIG.

12

. The bag neck is moved into a slot in the belt guard by brushes (not shown) and the product in the bag engages the belt guards when the neck of the bag is drawn by gathering belts

22

and

32

around a bag stop lever

80

. It should be appreciated that other and further gathering structures may be used to form a gathered neck on a bag.

Terms such as “left,” “right,” “clockwise,” “counter-clockwise,” “horizontal,” “vertical,” “up,” and “down” when used in reference to the drawings, generally refer to orientation of the parts in the illustrated embodiment and not necessarily during use. These terms used herein are meant only to refer to relative positions and/or orientations, for convenience, and are not to be understood to be in any manner otherwise limiting.

As illustrated in

FIG. 7

of the drawing, motor M

1

is driven by a solid state DC motor controller

91

which is capable of varying the speed of motor M

1

to substantially synchronize movement of upper gathering belt

22

and lowering gathering belt

33

with the speed of a conveyor

300

moving packages

125

adjacent the bag gathering mechanism

20

. For example, if the tier

10

is to gather and tie the necks of 100 bags per minute, the conveyer

300

would preferably bring bags to and through the tier at a speed of approximately 300 feet per minute and the gathering belts

22

and

32

would preferably be driven at a speed of, for example 305 feet per minute, so that the neck of the bag would be accelerated for gathering the neck, stopped momentarily while it is being tied with a ribbon and then discharged in a substantially continuous operation.

As will hereinafter be more fully explained, the gathering assembly

20

also includes a bag stop lever

80

, illustrated in

FIGS. 2 and 3

, mounted on shaft

85

for rotary movement about a horizontal axis, in the illustrated embodiment. Shaft

85

extends through an electric brake

82

, which momentarily locks lever

80

in a lowered position extending across path

12

such that gathering belts

22

and

32

move the bag neck into engagement with lever

80

. After the bag neck has been gathered and tied, the electric brake

82

is released and the gathered neck, carried between belts

22

and

32

, urges the lever

80

upwardly such that it does not obstruct movement of the gathered neck. After the gathered neck passes lever

80

, the lever

80

moves back to the illustrated position extending across path

12

.

A needle assembly

40

, best illustrated in

FIGS. 1-4

and

7

, is positioned for wrapping a strand

15

of ribbon material around a gathered neck of a bag. The needle assembly

40

comprises a needle

42

carrying idler rollers

44

,

44

a

and

44

b.

The needle

42

is mounted on the output shaft

45

of a gear box

46

driven by motor M

2

. Needle

42

is shown in its home position in

FIGS. 1 and 2

of the drawing. Motor M

2

moves needle

42

from the full outline position to the dashed outline position, illustrated in

FIG. 2

of the drawing, and then reverses for moving the needle

42

back to the position illustrated in full outline in FIG.

2

.

Referring to

FIGS. 1

,

3

and

7

of the drawing, a twister hook assembly

50

comprises a twister shaft

52

rotatably mounted in a bearing

53

having a hook

54

on one end thereof and a pulley

55

on the other end. A drive pulley

56

is mounted on the drive shaft of motor M

3

and drives pulley

55

through a belt

58

.

As best illustrated in

FIGS. 1

,

2

,

5

and

7

of the drawing, a ribbon holder-shear assembly, generally designated by the numeral

60

, comprises a holder and shear assembly of the type disclosed in U.S. Design Pat. No. 307,281 to Charles E. Burford and U.S. Pat. No. 4,856,258 entitled WIRE TYING DEVICE, which issued Aug. 15, 1989, to Charles E. Burford and Jimmy R. Frazier. The holder-shear assembly

60

comprises a gripper arm

62

having a gripper finger

64

on one end thereof rotatably secured to a mounting plate

66

by bolt

65

. A pair of anvils

68

and

69

are formed on the end of mounting plate

66

, each being associated with shear surfaces

68

a

and

69

a

to grip and cut a strand of ribbon as will be hereinafter more fully explained.

Referring to

FIGS. 5 and 7

of the drawing, a cam

70

is mounted on the shaft of motor M

4

and is configured to engage cam-followers

72

and

74

on spaced arms

71

and

73

secured to and actuating rod

75

mounted for reciprocating movement in bearings

76

. A link

75

a

secures the end of gripper arm

62

to actuating rod

75

.

It should be readily apparent when the shaft of motor M

4

rotates one-half revolution, cam

70

will exert force through cam-followers

72

and

74

for moving actuating rod

75

for pivoting the actuating arm

62

about bolt

65

. The free end of the ribbon is gripped between the end of gripper finger

64

and anvil

68

or

69

, depending on which direction the gripper finger

64

is shifted. As will be hereinafter more fully explained, when needle

42

wraps the intermediate section of the ribbon

15

around the gathered neck of a bag, the ribbon will be positioned between gripper finger

64

and the other anvil

68

or

69

. When gripper finger

64

is shifted to its opposite position, the ribbon will be cut and the free end of the strand of ribbon will be gripped between gripper finger

64

and anvil

68

or

69

.

Referring to

FIGS. 12 and 13

of the drawing, roller

41

has a plurality of index points

41

x.

In the illustrated embodiment, the index points are formed by steel dowel pins circumferentially spaced around the axis about which roller

41

rotates.

A proximity switch

41

s

is positioned near index pointers

41

x

for making an electrical circuit when the presence of an indexing pin

41

x

is sensed. The proximity switch

41

s

is of conventional design and is connected through a suitable power supply and amplifier to the CPU

96

.

Thus, the CPU monitors the proximity output and counts the pulses produced by index pins

41

x

in roller

41

. The CPU

96

calculates the amount of ribbon dispensed to determine whether or not a bag neck is present as needle

42

moves from the full outline position illustrated in

FIG. 2

of the drawing toward the dashed outline position illustrated in

FIG. 2

of the drawing. If needle

42

did not wrap ribbon around a bag neck, the CPU will terminate a portion of the remainder of the cycle of operation so that holder-shear

65

will not be actuated to prevent releasing the end of ribbon

15

which is gripped between gripper finger

64

and anvil

68

or

69

.

Referring to

FIGS. 1

,

2

and

3

of the drawing, a bag stop lever

80

is mounted on a shaft

85

for rotary movement about a horizontal axis. Shaft

85

extends through an electric brake

82

and has a crank arm

85

a

secured thereto which is resiliently urged in a clockwise direction, as viewed in

FIG. 3

, by a spring

83

.

A switch

86

is actuated by switch arm

88

, which actuates a timer for energizing electric brake

82

which momentarily locks bag stop

80

in a fixed position for a predetermined period of time, for example 0.25 seconds for restraining the leading edge of a bag neck, such that gathering belts

22

and

32

will gather the neck adjacent bag stop

80

. Switch

86

also triggers a cycle of operation of the tag attachment device

100

. At the expiration of the predetermined period of time, electric brake

82

will be de-energized so that linear movement of the bag neck will rotate bag stop

80

upwardly to release the bag so that it will be moved away by the conveyor. Bag stop

80

is biased toward the position illustrated in

FIG. 3

of the drawing by a spring

83

. It should be readily apparent that the spring

83

may be replaced by a counter-weight, air cylinder or other suitable biasing mechanism to resiliently urge bag stop

80

toward its home position.

Motors M

1

, M

2

, M

3

and M

4

are bi-directional, permanent magnet, DC brush-type servomotors having outputs proportional to the voltage applied across the armatures. Such motors are commercially available from Groschopp, Inc. of Sioux Center, Iowa as a “Power Master 8304” 24 volt DC continuous power motor. At 1500 rpm the motor generates 16 oz-in torque and has an output of 0.090 horsepower at 4.2 amps. At 2450 rpm the torque is 47 oz-in and the output is 0.113 horsepower at 5 amps. At 5400 rpm the torque is 37 oz-in and the output is 0.197 horsepower at 8.2 amps.

It is noted that other motors and motors of other sizes may be provided to facilitate driving the various assemblies. For example, it is contemplated that smaller motors would be used in a counter top model used for gathering and fastening materials such as coils of electrical cord, water hose, tubing, or yarn, and bundles of cable, rods, or carrots and other produce.

One side of the armature winding of each motor M

1

, M

2

, M

3

and M

4

is connected to ground such that reversing the polarity of current through the armature winding reverses the direction of rotation of the motor.

Each of the motors M

1

, M

2

, M

3

and M

4

has an encoder E

1

, E

2

, E

3

or E

4

mounted on its drive shaft which delivers an electrical signal to a decoder D

1

, D

2

, D

3

or D

4

which is representative of the position of the motor shaft.

Referring to

FIG. 7

of the drawing, the numeral

90

generally designates a power supply for delivering electric current to motor controller

91

and to motor M

1

in the bag neck gathering mechanism

20

; motor controller

92

and motor M

2

in the needle assembly

40

; motor controller

93

and motor M

3

in the twister assembly

50

; and motor controller

94

and motor M

4

in the holder-shear assembly

60

. The power supply

90

comprises a pair of single-phase, doughnut transformers T

1

connected in parallel. The supply or primary circuits of transformers T

1

are connectable to any suitable source of electricity such as 115 volt, 60 cycle, single-phase electricity. The energy receiving or secondary circuits of transformers T

1

are connected through one or more rectifier bridge circuits B

1

and B

2

and capacitors C

6

and C

7

to a pair of controlled voltage power terminals, one of which forms a source of direct current maintained at positive 34 volts and the other a source of direct current at negative 34 volts.

The 34 volt and 8 volt power supplies illustrated in

FIG. 7

is of conventional design and form no part of the present invention except in combination with the other elements of the control circuit. It should be appreciated that many other DC power supplies may be used in lieu of those illustrated in the drawing.

Conventional multichannel incremental optical encoders E

1

, E

2

, E

3

and E

4

are mounted on the shaft of each motor M

1

, M

2

, M

3

and M

4

, respectively. The encoders E

1

-E

4

are high resolution incremental optical devices which include an encoder body, a metal code wheel and emitter end plate. An LED source and lenses transmit collimated light from the emitter diode through a precision metal code wheel and phase plate into a bifurcated detector lens (not shown).

The light is focused onto pairs of closely spaced integrated detectors which output two square wave signals in quadrature and an optional index pulse.

HEDS-6000 series, two and three channel incremental optical encoder kits are available from Hewlett Packard of Palo Alto, Calif. A standard selection of shaft sizes and resolutions between 192 and 1024 cycles per shaft revolution are available. The part number for a standard two-channel encoder is HDS-6000, while that for the three-channel device, with index pulse, is HEDS-6010. The encoder devices are typically used for printers, plotters, tape drives, positioning tables, automatic handlers, robots, and other servo loop applications. Specific details of construction of the incremental optical encoder can be found in Hewlett Packard Publication No. 5954-8420 (3/87) which is incorporated herein by reference.

The incremental shaft encoder operates by translating the rotation of a shaft into interruptions of a light beam which are then output as electrical pulses. The light source is a light emitting diode collimated by a molded lens into a beam of parallel light. An emitter end plate contains two or three similar light sources, one for each channel.

The code wheel is a metal disc that has N equally spaced slits around its circumference. An aperture with a matching pattern is positioned on a stationary phase plate. The light beam is transmitted only when the slits in the code wheel and the aperture line up; therefore, during a complete shaft revolution, there will be N alternating light and dark periods. A molded lens beneath the phase plate aperture collects the modulated light into a silicon detector.

The encoder body contains the phase plate and the detection elements for two or three channels. Each channel consists of an integrated circuit with two photo-diodes and amplifiers, comparator, and output circuitry (not shown).

The apertures for the two photo-diodes are positioned so that a light period on one detector corresponds to a dark period on the other. The photo-diode signals are amplified and fed to a comparator whose output changes state when the difference of the two photo currents changes sign. The second channel has a similar configuration but the location of its aperture pair provides an output which is in quadrature to the first channel (phase difference of 90°). Direction of rotation is determined by observing which of the channels is the leading waveform. The outputs are TTL logic level signals.

The motion sensing application and encoder interface circuitry will determine the need for relating the index pulse to the main data tracks. A unique shaft position is identified by using the index pulse output only or by logically relating the index pulse A and B data channels. The index pulse can be uniquely related to the A and B data tracks in a variety of ways. State width, pulse width or edge transitions can be used.

The two square wave signals in quadrature of channels A and B and a 5 volt supply input are delivered through a 10-pin connector to a corresponding decoder D

1

, D

2

, D

3

or D

4

mounted on an auxiliary board, as illustrated in

FIG. 7

of the drawing. Lines connecting encoders E

2

to a decoder D

2

are illustrated. Encoders E

3

and E

4

are similarly connected to decoders D

3

and D

4

.

Quadrature decoders D

1

-D

4

are CMOS (complimentary metal-oxide semiconductor) integrated circuits that perform the quadrature decoder, counter, and bus interface functions. “HTCL-2000,” commercially available from Hewlett Packard, quadrature decoder/counter interface IC decoder interfaces an encoder to a microprocessor and is designed for use in digital closed loop motion control systems and digital data input systems.

The decoder includes a 4× quadrature decoder, a binary up/down state counter and a 16-bit bus interface. A Schmitt-triggered CMOS input and input noise filters are incorporated in the device.

Further information regarding the quadrature decoder/counter interface IC for interfacing to Motorola and Intel microprocessors can be found at page 1-61 through page 1-76 of Hewlett Packard Publication for “HCTL-2000,” “HCTL-2016,” “HCTL-2020.”

Decoders D

1

-D

4

have pins for a channel A and channel B Schmitt-trigger inputs which accept the outputs from quadrature encoders E

1

-E

4

. The two channels are preferably 90° out of phase.

The system is controlled by a computer

95

, illustrated in

FIG. 6

, which receives and stores a set of instructions and then acts upon the instructions in a predetermined and predictable fashion. A microprocessor

96

is attached to a printed circuit board into which a thin layer of metal has been applied and then etched away to form traces. The electronic components of the central processing unit are attached to the board with solder so that they can change electronic signals through the etched traces on the board.

A suitable 32-bit integrated microcontroller

96

is the MC68332 which is commercially available from Motorola, Inc. of Schaumburg, Ill. as a product referred to as “MC68332 SIM” System Integrated Module. A complete documentation package of the MC68332 consists of the (SIM 32UM/AD), MC68332

System Integration Module User's Manual,

the (CPU32RM/AD), CPU32

Reference Manual

, and the TPU32RM/AD),

Time Processing Unit Reference Manual.

The MC68332

System Integration Module User's Manual

describes the capabilities, registers, and operation of the MC68332 MCU. The

CPU Reference Manual

describes the operation, programming and instruction set of the CPU32 processor used in the MC68332. The

Time Processing Unit Reference Manual

describes the autonomous timer system used in the MC68332.

The MC68332 microcontroller

96

contains intelligent peripheral modules such as the time processor unit (TPU) which provides 16 microcoded channels for performing time-related activities for simple input capture or output capture to complicated motor control or pulse width modulation. High-speed serial communications are provided by the queued serial module (QSM) with synchronous and asynchronous protocols available. Two kilobytes of fully static standby RAM allow fast two-cycle access for system and data stacks and variable storage with provision for battery backup. Twelve chip selects enhance system integration for fast external memory or peripheral access. These modules are connected on-chip via an intermodule bus (IMB).

The MC68332 microcontroller

96

is a 132-pin plastic quad flat pack that operates at a frequency of 16.78 MHZ with a 5 volt supply and is software programmable. It has 16 independent programmable channels and pins. Any channel can perform any time function including input capture, output compare or pulse width modulation (PWM).

The detailed logical procedures or algorithms processed by the microcomputer are proportional integral derivative (PID) type control mode signals. The PID control mode combines the best action of proportional control, integral control and derivative control in a closed loop control system.

In addition to the microcontroller chip

96

on the CPU board, random-access memory (RAM) integrated circuits

97

are used for storing values in distinct locations which can be recalled or altered for storing the software which controls the system. Since the values which are in RAM memory are lost when the power of the computer is turned off, a battery backup is provided. The microcontroller

96

processes digital signals, such as the presence or absence of voltages, to represent values.

The CPU board is connected to an auxiliary board

98

through a connector header which carries data signals and address signals. Driver circuits C

1

-C

4

, which generate pulse width modulated (PWM) signals, are mounted on the auxiliary board along with the decoders D

1

-D

4

. The pulse width modulated signals from driver circuits C

1

-C

4

are sent to the motor drivers

91

-

94

selectively delivering positive or negative DC power to control the operation of motors M

1

-M

4

.

The circuits carrying input signals from the encoders E

1

-E

4

to decoders D

1

-D

4

; the circuit carrying pulse width modulated signals from driver circuits C

1

-C

4

to motor drivers

91

-

94

; and the circuits carrying power from the motor drivers

91

-

94

to motors M

1

-M

4

form a closed loop control system. The closed loop control system depends upon the feedback concept for operation and the output PWM signals are forced to a preassigned function of the reference input of the microcontroller of the central processing unit. The microcontroller

96

sends control PWM signals determined by the programmed movements stored in RAM memory in a pre-assigned order as a function of time after switch arm

88

returns to its home position illustrated in FIG.

3

. The control PWM signals are delivered to the control circuit. Each encoder E

1

-E

4

, connected to the shaft of motors M

1

-M

4

, send quadrature signals to the decoders D

1

-D

4

that indicate the position of the shaft of each motor. The control PWM signals delivered to each control circuit C

1

-C

4

are delivered to motor drivers

91

-

94

. The quadrature signals from decoders D

1

-D

4

are read to adjust the control PWM signals.

Drivers

92

,

93

and

94

, which control the delivery of power to motors M

2

, M

3

and M

4

, respectively, for controlling the needle assembly

40

, twister hook assembly

50

and holder-shear mechanism

60

are substantially identical. One side of the winding of each of the motors M

2

, M

3

and M

4

is connected to ground. Drivers

92

,

93

and

94

deliver either positive or negative power to the other side of the motor winding for driving motors M

2

, M

3

and M

4

in opposite directions. For example, when positive

34

volt direct current is delivered to the winding of motor M

2

, its shaft is driven in a clockwise direction. If negative 34 volt direct current is delivered to the winding of motor M

2

, its shaft will be driven in a counter-clockwise direction.

The driver

91

for motor M

1

connected to the bag gathering assembly

20

, is similar to drivers

92

,

93

and

94

except that driver

91

is not provided with the capability of delivering negative direct current because it is not necessary for motor M

1

to be driven in reverse.

Software is stored in FEEPROM memory on the CPU board for controlling the acceleration, speed and position of the shaft of each motor M

1

-M

4

.

FIG. 11

is a graphic representation of the sequence of operation of the needle, hook and shear assemblies during a complete cycle of operation. The microcontroller

96

is initially programmed by a computer through a serial port RS for storing a program which will initiate movement of needle

42

from its home position illustrated in FIG.

3

and the speed of movement toward the dashed outline position illustrated in

FIG. 3

controlled by signals delivered through control circuit C

2

to motor M

2

. While needle

42

is moving from the position illustrated in full outline toward the position illustrated in dashed outline, the program causes a signal to be sent from control circuit C

3

to motor M

3

to begin rotating twister hook

54

and continue rotation of twister

54

a predetermined number of revolutions controlled by the motion profile in RAM memory. Similarly, when needle

42

and twister hook

54

are in predetermined positions, a signal will be sent from driver circuit C

4

which will energize motor M

4

for rotating cam

70

to move the gripper finger

64

to release the free end of the ribbon and shear a segment from the end of the strand of ribbon. At a time controlled by the software, a signal will be delivered to motor M

2

for moving needle

42

from the position shown in dashed outline in

FIG. 3

back to its home position. A signal will be delivered to motor M

3

for rotating twister hook

54

two revolutions in the reverse direction for slinging the tie, which has been twisted around the neck of a bag, out of the twister hook

54

for completing a tying cycle.

It should be readily apparent that when the neck of a bag moves between gathering belts

22

and

32

, switch arm

88

will be moved downwardly from the position illustrated in

FIG. 3

which will energize electric brake

82

so that belts

22

and

32

will move the neck of the bag into engagement with bag stop

80

causing the neck to be gathered. As the trailing edge of the neck of the bag passes over the end of switch arm

88

, switch arm

88

will move back to the position illustrated in

FIG. 3

causing switch

86

to send a signal to the microcontroller for starting a new tying cycle.

Referring to

FIG. 9

of the drawing the numeral

100

generally designates a tag attachment device having a frame

100

formed by a generally vertically extending frame portion

111

and a generally horizontally extending frame portion

112

. A driven roller

120

is mounted on the shaft

120

a

of an electric motor

120

b.

Idler pulleys

121

,

122

,

123

,

124

,

125

and

126

are rotatably mounted on frame plate

110

. A tag feed belt

115

extends around and is driven by driven roller

120

in a counter-clockwise direction as viewed in

FIG. 9

of the drawing around idler rollers

121

,

122

,

123

,

124

,

125

and

126

. It should be noted that idler rollers

121

,

124

and

125

are mounted on shafts extending through slots in frame plate

110

to permit adjustment of the position of the rollers for controlling belt tension and frictional force exerted on a tag, as will be hereinafter more fully explained.

Feed rollers

133

and

134

are mounted in a parallel linkage mechanism

130

. A bell crank having arms

133

a

and

133

b

supports roller

133

and is pivotally secured to a mounting plate

132

by a pin

133

c.

Roller

134

is mounted on a bell crank having arms

134

a

and

134

b

pivotally secured by a pin

134

c

to mounting plate

132

. A link

135

has opposite ends secured by pins

135

a

and

135

b

to arms

133

a

and

134

a

of the bell cranks such that the bell cranks move in unison and move rollers

133

and

134

into and out of engagement with belt

115

. The rod

139

of an air cylinder

138

is preferably connected to pin

135

b

for actuating the parallel linkage mechanism

130

for feeding tags through the system, as will be hereinafter more fully explained.

A guide plate generally designated by the numeral

140

has an inclined section

144

between end

142

and deflected portion

143

and a generally horizontally extending portion

146

between deflected portion

143

and curved guide surface

145

. When a tag is positioned on end

142

of guide plate

140

, it will be moved by belt

115

when the parallel linkage mechanism

130

is actuated for moving the tag downwardly along portion

144

and along portion

146

through a slot

147

between holder pin

148

and curved guide surface

145

.

Belt

115

is preferably driven continuously. When cylinder

138

is actuated, rod

139

is extended which rotates the bell cranks carrying rollers

132

and

134

simultaneously into engagement with belt

115

. As will be hereinafter more fully explained, an electric eye

165

senses the position of tags for controlling actuation of double acting cylinder

138

for raising and lowering rollers

133

and

134

.

A cutter

150

is mounted adjacent end

142

of guide plate

140

for severing individual tags from a series of tags. A driven roller

160

and an idler roller

162

form a nip adjacent opposite sides of a continuous series of tags for drawing the strip of tags through tag entry area

186

, adjacent to electric eye

165

into the nip between rollers

160

and

162

. The strip of tags is pushed through cutter

150

into space between belt

115

and guide plate

140

.

Strip

180

of tags, as illustrated in

FIG. 10

, comprises a series of tags

181

,

182

and

183

joined by connectors

185

. Cutter

150

cuts through tags

181

,

182

and

183

to form a body portion

182

a

on one end of connector

185

and a tail piece

181

a

on the other end of connector

185

.

Referring to

FIG. 10

of the drawing, tags in a continuous strip

180

are supplied on a roll or spool mounted on a spool holder

186

. The spool holder includes a spring clutch for holding tension on the strip

180

as tags are unrolled from the roll. The spring clutch includes a backup feature that backs up the roll approximately ¼ to ½ turn for taking up any backlash that might occur as the roll stops. The spool holder preferably has transparent sides to keep the roll of tags straight and to guide them as they unroll from the spool.

The continuous strip

180

extends into the entry area

168

of tag attachment device

100

, as best illustrated in

FIG. 9

of the drawing. The tag entry area is preferably formed by a pair of side guide members for controlling the tag position laterally and an entry rod under which the tags pass for aligning the tags. It should be readily apparent that the entrance angle of the strip

180

into the tag entry area will vary as the diameter of the spool decreases as tags are used.

As best illustrated in

FIG. 9

of the drawing, electric eye

165

is positioned to sense the position of the tags. Each tag has a black mark or other indicia thereon so that the photo eye can sense the relative position of each tag. The position of the photo eye

165

can be adjusted so that the distance between the mark and the cutter

150

can vary.

Pinch rollers

160

and

162

and cutter

150

are arranged to form a tag drive and cutting area. A clutch and brake control connected to drive roller

160

allow pinch rollers

160

and

162

to stop and start when demanded by the trigger switch

86

actuated when the neck of a bag engages switch arm

88

.

Cutter

150

is a dual blade rotating cutter that allows tag stock to travel through the cutter and to cut with 180° rotation of the dual blade. The clutch, brake and pinch roller bearings are mounted in a tag drive box.

As hereinbefore described, the tag feed area adjacent end

142

of guide plate

140

allows a cut tag to be fed to the front of the servo tyer. The feed area moves the tag by pinching the tag between rubber belt

115

and the inclined portion

144

of guide plate

140

. Before a tag is cut along the dotted line, illustrated in

FIG. 10

, belt

115

is held up out of engagement with the strip of tags. After a tag has been cut, piston rod

139

of cylinder

138

is extended pushing belt

115

toward portion

144

of guide plate

140

to pinch the tag and drive the tag to a holding area adjacent curved end

145

of guide plate

140

.

The portion of guide plate

140

between roller

125

and holder pin

148

bridges gathering belt

22

between rollers

26

and

27

so that movement of the rod of pressure actuated cylinder

26

c

will rotate bell crank

26

a

about pin

26

b

for moving pulley

26

toward guide plate

140

. The connector

185

between tag

182

and tail

181

a

will be engaged by belt

22

and wiped laterally with the bag neck away from the tag attachment device

100

.

As illustrated in

FIG. 8

of the drawing, cover

170

is formed by a back plate

172

secured to a cover plate

174

for forming a pocket into which the body portion

182

a

of the tag extends when it passes under holder pin

148

and is deflected upwardly by curved portion

145

of guide plate

140

. The body portion of the tag moves through an entrance slot

173

into the pocket where the body portion

182

a

is deflected to a substantially vertical position as it moves through the pocket and out of a discharge slot

175

. The connector portion

185

extends generally horizontally, as viewed in FIG.

8

.

When cylinder

26

c

is actuated moving pulley

26

, the upper surface of connector

185

is engaged by belt

22

and the lower surface of connector

185

engages the neck of the bag causing the tag to be moved through the pocket and through the exit slot

175

. Thus, the tag is positioned adjacent the bag while connector portion

185

is moved along with the neck of the bag toward bag stop lever

80

. The neck of the bag and connector portion

185

are encircled by ribbon

15

to securely attaching the tag to the bag.

When neck of a bag engages arm

88

the motor driving the driven pinch roller

160

is energized causing the strip of tags to be advanced. The trigger signal from the servo tyer trigger switch

86

and photo eye

165

provide the input signals for controlling the tag attachment device

100

. Outputs from the electric controller include power for the variable speed motor

120

b

having a shaft for driving the driven roller

120

. Signals are also delivered to the clutch that controls rotation of pinch roller

160

and a brake. A cutter control signal and air cylinder control signal for actuating the parallel linkage mechanism

130

are also sent. In addition, a signal is sent for actuating air cylinder

26

c

for moving gathering belt

22

into engagement with the tag.

It is to be understood that while detailed descriptions of a preferred embodiment has been illustrated and described, the invention is not to be limited to the specific arrangement of parts and specific features herein described and illustrated in the drawing. Rather, the descriptions are merely of an exemplary embodiment of the invention, which may be embodied in various forms.

A modified form of the apparatus is illustrated in

FIGS. 11

,

12

and

13

of the drawing. Referring to

FIGS. 9 and 11

, it will be noted that rollers

132

and

134

for urging the belt

115

have been replaced by a roller

233

, as best illustrated in

FIG. 13

of the drawing. Roller

233

is mounted on arm

233

a

of a bell crank pivotally supported on a pin

233

c.

A pin

235

a

pivotally secures arm

233

a

to one end of a link

235

. The opposite end of link

235

is pivotally connected by a pin

235

b

to a linear actuator, such as solenoid

240

.

As best illustrated in

FIG. 11

of the drawing, a spool holder generally designated by the numeral

200

includes a bar

202

pivotally secured by a pin

204

to the upper end of a post

205

and has idler rollers

206

and

208

mounted thereon. A spool

210

of tag material is rotatably mounted on bar

202

. Strip

180

of tags extends from spool

210

around idler rollers

209

,

208

,

207

and

206

into a funnel

210

at the entry area

168

into tag attachment device

100

.

A spring

201

urges bar

202

from the position shown in dashed outline to the position illustrated in full outline for maintaining tension on the strip

180

of tags.

A belt

163

extends around driven roller

160

and idler roller

164

for advancing strip

186

toward cutter

150

.

Number	Name	Date	Kind
3375634	Jarund	Apr 1968	A
3589092	Jarund	Jun 1971	A
3919829	Burford et al.	Nov 1975	A
4062383	Saito	Dec 1977	A
4215606	Britt	Aug 1980	A
4398379	Burford	Aug 1983	A
4711064	Tsuda	Dec 1987	A
4856258	Burford et al.	Aug 1989	A
5483134	Frazier et al.	Jan 1996	A
5708339	Frazier et al.	Jan 1998	A
5771664	Recchia, Jr.	Jun 1998	A

Tag insertion device for a bag tyer

Information

Patent Number

Date Filed

Date Issued

Inventors

Original Assignees

Examiners

Agents

CPC

US Classifications

Field of Search

US

International Classifications

Abstract

Description

Claims

US Referenced Citations (11)