Patent Description:
The bag-making and packaging machine disclosed in patent document <NUM> (<CIT>) has sealing jaws that perform a transverse sealing operation. The sealing jaws can move in the up and down direction, which is the conveyance direction of a film for packaging. The mechanism that moves the sealing jaws up and down includes a servo motor that rotates in one direction and a link mechanism that converts the rotational force of the servo motor into up and down reciprocal motion and transmits it to the sealing jaws.

<CIT> discloses a bag-making and packaging machine according to the preamble of claim <NUM>.

<CIT> discloses a lateral seal controller of a bag-making and packaging machine.

<CIT> discloses a horizontal seal mechanism of a bag making and packaging machine.

Patent document <NUM> contains no description in regard to rotating the servo motor in both forward and reverse directions.

It is a problem of this disclosure to utilize bidirectional rotation of a motor in a bag-making and packaging machine to improve the flexibility of operations that the bag-making and packaging machine executes.

A bag-making and packaging machine pertaining to the invention includes sealing jaws, a horizontal moving device, a vertical moving device, and a control unit, as set out in appended claim <NUM>. The sealing jaws perform a transverse sealing operation. The horizontal moving device moves the sealing jaws in a horizontal direction. The vertical moving device moves the sealing jaws in a vertical direction. The vertical moving device has a rotating shaft, a motor, and a link mechanism. The rotating shaft is capable of forward rotation and reverse rotation. The motor rotates the rotating shaft. The link mechanism transmits rotational force of the rotating shaft to a support body that supports the sealing jaws such that the support body and the sealing jaws move in the vertical direction. The control unit performs first control and second control. The first control forwardly rotates and reversely rotates the rotating shaft during the time from the start of one transverse sealing operation to the start of the subsequent transverse sealing operation. The second control performs one of one transverse sealing operation and the subsequent transverse sealing operation with a forward rotation of the rotating shaft and the other with a reverse rotation of the rotating shaft.

According to this configuration, the control unit can perform the first control and the second control. Consequently, there is greater flexibility in the operations that the bag-making and packaging machine executes.

Preferably, the link mechanism has a first link and a second link. The first link has a first link length, and has a first link first end coupled to the rotating shaft and a first link second end coupled to the second link. The second link has a second link first end coupled to the first link and a second link second end coupled to the support body that supports the sealing jaws. The first link second end moves through a region on a circle whose radius is the first link length and which includes a top dead center, a bottom dead center, a first half circle interconnecting the top dead center and the bottom dead center, and a second half circle on the opposite side of the first half circle.

According to this configuration, the link mechanism has the first link and the second link. Consequently, the rotational force of the rotating shaft can be transmitted by the first link and the second link to the sealing jaws.

Preferably, the first link second end at the end of the transverse sealing operation is positioned above the bottom dead center without being positioned at the bottom dead center.

According to this configuration, at the end of the transverse sealing operation, the first link second end is not positioned at the bottom dead center. Consequently, the operation subsequent to the transverse sealing operation can be smoothly started.

Preferably, the first link second end at the start of the transverse sealing operation is positioned below the top dead center without being positioned at the top dead center.

According to this configuration, at the start of the transverse sealing operation, the first link second end is not positioned at the top dead center. Consequently, the transverse sealing operation can be smoothly started.

Preferably, the first link second end at the end of the transverse sealing operation is positioned above the bottom dead center an amount corresponding to a rotation angle of <NUM>° or more.

According to this configuration, at the start of the transverse sealing operation, the first link second end is positioned above the bottom dead center an amount corresponding to a rotation angle of <NUM>° or more. Consequently, the sealing jaws can move further downward at the end of the transverse sealing operation, so jamming of the film that is conveyed can be inhibited.

Preferably, the first link second end at the start of the transverse sealing operation is positioned below the top dead center an amount corresponding to a rotation angle of <NUM>° or more.

According to this configuration, at the start of the transverse sealing operation, the first link second end is positioned below the top dead center an amount corresponding to a rotation angle of <NUM>° or more. Consequently, speed in the vertical direction for the sealing jaws to perform a stripping operation can be ensured.

Preferably, the control unit performs the second control. At the end of the transverse sealing operation the first link second end is positioned in one of the first half circle or the second half circle and thereafter passes through the bottom dead center to move to the other of the first half circle or the second half circle.

According to this configuration, the forward rotation and the reverse rotation of the rotating shaft are each executed one time each for every two transverse sealing operations. Consequently, the frequency of switches between the forward rotation and the reverse rotation is small, so the transverse sealing operation can be quickly performed.

Preferably, after the end of the transverse sealing operation the sealing jaws move downward at least one time.

According to this configuration, the first link second end moves downward after the end of the transverse sealing operation. Consequently, jamming of the film that is conveyed can be inhibited.

According to the invention, the control unit selectively performs one of the first control and the second control.

According to this configuration, the control unit is capable of executing both the first control and the second control. Consequently, control flexibility is improved.

According to the bag-making and packaging machine of this disclosure, there is greater flexibility in the operations that the bag-making and packaging machine executes.

An embodiment of the invention will be described below with reference to the drawings. It will be noted that the following embodiment is a specific example of the invention and is not intended to limit the technical scope of the invention.

<FIG> shows the overall configuration of a bag-making and packaging machine <NUM>. The bag-making and packaging machine <NUM> makes bags W from a film F and puts articles A inside to package the articles A. The bag-making and packaging machine <NUM> has a film roll support unit <NUM>, a former <NUM>, pull-down belts <NUM>, a longitudinal sealing device <NUM>, a transverse sealing device <NUM>, and a control unit <NUM>.

The film roll support unit <NUM> supports a film roll FR. The film F pulled out from the film roll support unit <NUM> heads toward the former <NUM> via plural rollers.

The former <NUM> forms the film F into a tube by bending the film F and overlapping the two longitudinal edges of the film F. The former <NUM> has a tube <NUM> and a sailor's collar <NUM>. The tube <NUM> also functions as a guide path for the articles A. The sailor's collar <NUM> guides the film F between the sailor's collar <NUM> and the tube <NUM> while curving the film F.

The pull-down belts <NUM> are driven by a motor not shown in the drawings to convey the tubular film F downward along the tube <NUM>.

The longitudinal sealing device <NUM> bonds the two parallel edges of the film F extending in the conveyance direction to make a film tube FT. The longitudinal sealing device <NUM> heats, while applying pressure to, the two edges of the film F overlapping each other on the tube <NUM>. The longitudinal sealing device <NUM> has a heater and a heater belt, for example.

The transverse sealing device <NUM> bonds two opposing surfaces of the film tube FT to make the bags W. The transverse sealing device <NUM> has a first sealing jaw <NUM> and a second sealing jaw <NUM>. The first sealing jaw <NUM> and the second sealing jaw <NUM> can each move in a horizontal direction H toward or away from each other. In addition, the first sealing jaw <NUM> and the second sealing jaw <NUM> can also move in a vertical direction V.

The control unit <NUM> controls the motor of the pull-down belts <NUM>, the longitudinal sealing device <NUM>, the transverse sealing device <NUM>, and other actuators, and also processes signals from various sensors. The control unit <NUM> comprises a processor, for example.

<FIG> shows the detailed configuration of the transverse sealing device <NUM>. The transverse sealing device <NUM> has a frame base <NUM>, a horizontal moving frame <NUM>, a slide member <NUM>, a horizontal moving device <NUM>, a vertical moving device <NUM>, the first sealing jaw <NUM>, and the second sealing jaw <NUM>.

The frame base <NUM> shown in <FIG> has a first side frame <NUM>, a second side frame <NUM>, a first coupling member <NUM>, a second coupling member <NUM>, and plural guides <NUM>. The first coupling member <NUM> and the second coupling member <NUM> both couple the first side frame <NUM> and the second side frame <NUM> to each other. Each of the guides <NUM> is secured to the first side frame <NUM> or the second side frame <NUM>.

The horizontal moving frame <NUM> has a square shape. The horizontal moving frame <NUM> is movable in the horizontal direction H with respect to the frame base <NUM>. The horizontal moving frame <NUM> has a first slide rod <NUM>, a second slide rod <NUM>, a first base member <NUM>, and a second base member <NUM>. The first slide rod <NUM> is disposed along the first side frame <NUM>. The second slide rod <NUM> is disposed along the second side frame <NUM>. To both ends of the first slide rod <NUM> and the second slide rod <NUM>, the first base member <NUM> and the second base member <NUM> are secured respectively. The first slide rod <NUM> and the second slide rod <NUM> are slidably supported by the plural guides <NUM> of the frame base <NUM>.

The slide member <NUM> bridges the first slide rod <NUM> and the second slide rod <NUM>. Both ends of the slide member <NUM> are provided with sliders <NUM>. The sliders <NUM> can slide in the horizontal direction H with respect to the first slide rod <NUM> and the second slide rod <NUM>.

The horizontal moving device <NUM> has a horizontal moving motor <NUM> and a horizontal link mechanism <NUM>.

The horizontal moving motor <NUM> generates power that moves the first sealing jaw <NUM> and the second sealing jaw <NUM> in the horizontal direction H. The horizontal moving motor <NUM> can rotate in both a forward direction and a reverse direction.

The horizontal link mechanism <NUM> transmits the power of the horizontal moving motor <NUM> to the horizontal moving frame <NUM> and the slide member <NUM>. As shown in <FIG>, the horizontal link mechanism <NUM> has a first link <NUM>, a second link <NUM>, and a third link <NUM>. To the center of the first link <NUM>, a rotating shaft 58a is secured. The rotating shaft 58a is rotated by the horizontal moving motor <NUM>. The rotating shaft 58a can rotate in both a forward direction and a reverse direction. The rotating shaft 58a may be a shaft directly coupled to a rotor of the horizontal moving motor <NUM>. Alternatively, the rotating shaft 58a may be a shaft rotated by a gear box or a belt attached to the horizontal moving motor <NUM>. In accompaniment with the rotation of the rotating shaft 58a, the first link <NUM> also rotates. To both end portions of the first link <NUM>, the second link <NUM> and the third link <NUM> are rotatably coupled respectively. The second link <NUM> is coupled to the second base member <NUM>. The third link <NUM> is coupled to the slide member <NUM>.

The first sealing jaw <NUM> is installed on the first base member <NUM> of the horizontal moving frame <NUM>. The second sealing jaw <NUM> is installed on the slide member <NUM>. The first sealing jaw <NUM> and the second sealing jaw <NUM> are provided with heaters not shown in the drawings. Moreover, at least one of the first sealing jaw <NUM> and the second sealing jaw <NUM> is provided with a movable knife not shown in the drawings.

In <FIG>, the first sealing jaw <NUM> and the second sealing jaw <NUM> are in positions near each other. When the rotating shaft 58a rotates a predetermined angle, the horizontal link mechanism <NUM> switches to the arrangement shown in <FIG>. In <FIG>, the first sealing jaw <NUM> and the second sealing jaw <NUM> are in positions away from each other. When, in the state in <FIG>, the rotating shaft 58a rotates in the reverse direction, the horizontal link mechanism <NUM> returns to the arrangement shown in <FIG>.

The vertical moving device <NUM> shown in <FIG> has a vertical moving motor <NUM> and a vertical link mechanism <NUM>.

The vertical moving motor <NUM> generates power for moving the first sealing jaw <NUM> and the second sealing jaw <NUM> in the vertical direction V. The vertical moving motor <NUM> can rotate in both a forward direction and a reverse direction.

The vertical link mechanism <NUM> transmits the power of the vertical moving motor <NUM> to the frame base <NUM>. The vertical link mechanism <NUM> has a first link <NUM> and a second link <NUM>. To one end of the first link <NUM>, a rotating shaft 59a is secured. The rotating shaft 59a is rotated by the vertical moving motor <NUM>. The rotating shaft 59a can rotate in both a forward direction and a reverse direction. The rotating shaft 59a may be a shaft directly coupled to a rotor of the vertical moving motor <NUM>. Alternatively, the rotating shaft 59a may be a shaft rotated by a gear box or a belt attached to the vertical moving motor <NUM>. In accompaniment with the rotation of the rotating shaft 59a, the first link <NUM> also rotates. To the other end of the first link <NUM>, the second link <NUM> is rotatably coupled. The second link <NUM> is coupled to the first side frame <NUM> or the second side frame <NUM> of the frame base <NUM>. When the rotating shaft 59a rotates, the frame base <NUM> moves in the vertical direction V, and therefore the first sealing jaw <NUM> and the second sealing jaw <NUM> move up and down.

<FIG> shows the operation of the first sealing jaw <NUM> and the second sealing jaw <NUM>. The period in which the transverse sealing operation is performed is called a cycle. One cycle comprises four phases, that is, a first phase to a fourth phase.

At the start of the first phase, the first sealing jaw <NUM> and the second sealing jaw <NUM> are away from each other. In the first phase, the first sealing jaw <NUM> and the second sealing jaw <NUM> move in the horizontal direction H toward each other. When the first sealing jaw <NUM> and the second sealing jaw <NUM> start pressing the film tube FT, the first phase ends.

At the start of the second phase, the first sealing jaw <NUM> and the second sealing jaw <NUM> press the film tube FT. This signifies the start of the transverse sealing operation. Next, the first sealing jaw <NUM> and the second sealing jaw <NUM> strip the film tube FT by moving a predetermined distance downward in the vertical direction V faster than the conveyance speed of the film tube FT. Next, the first sealing jaw <NUM> and the second sealing jaw <NUM> apply heat to the film tube FT to make a transversely sealed portion in the bags W. Next, the knife provided in the first sealing jaw <NUM> or the second sealing jaw cuts the transversely sealed portion. The cutting of the transversely sealed portion signifies the end of the transverse sealing operation. With this, the second phase also ends. It will be noted that the conveyance of the film tube FT may also be stopped during the transverse sealing operation.

In the third phase, the first sealing jaw <NUM> and the second sealing jaw <NUM> at least move in the horizontal direction H away from each other. When the distance separating the first sealing jaw <NUM> and the second sealing jaw <NUM> reaches a maximum, the third phase ends.

In the fourth phase, the first sealing jaw <NUM> and the second sealing jaw <NUM> move a predetermined distance upward in the vertical direction V. When the upward movement ends, the fourth phase ends.

<FIG> is a schematic view of the vertical link mechanism <NUM>. The length of the first link <NUM> is a first link length r. The first link <NUM> has a first link first end 91a and a first link second end 91b. The second link <NUM> has a second link first end 92a and a second link second end 92b. The first link first end 91a is secured to the rotating shaft 59a. The first link second end 91b is coupled to the second link first end 92a. The second link second end 92b is coupled to the frame base <NUM>. The rotation of the rotating shaft 59a moves the frame base <NUM> in the vertical direction V.

<FIG> is a schematic view of the first link <NUM> of the vertical link mechanism <NUM>. The first link <NUM> can rotate in a forward direction R or a reverse direction -R as a result of the rotating shaft 59a rotating in the forward direction or the reverse direction. An angle θ of the first link <NUM> shown in <FIG> indicates the degree of rotation of the first link. When the first link <NUM> rotates in the forward direction R, the angle θ increases. A path P of the first link second end 91b follows a circle whose radius is the first link length r. An angle θ of <NUM>° corresponds to a top dead center T. An angle θ of <NUM>° corresponds to a bottom dead center B. The region of the circular path corresponding to an angle θ of <NUM>° or more and less than <NUM>° is a first half circle h1. The region of the circular path P corresponding to an angle θ of <NUM>° or more and less than <NUM>° is a second half circle h2.

The control unit <NUM> selectively implements one of first control and second control described below.

The first control is control that forwardly rotates and reversely rotates the rotating shaft 59a during the time from the start of one transverse sealing operation to the start of the subsequent transverse sealing operation (i.e., during one cycle). <FIG> is a schematic diagram showing the operation of the first link <NUM> under the first control in two cycles.

At the start of the first phase of the first cycle, the first link second end 91b is in the first half circle h1. The angle θ of the first link <NUM> is set to an initial value θ<NUM>. The initial value θ<NUM> exceeds at least <NUM>°, and the first link second end 91b is below the top dead center T. The initial value θ<NUM> is, for example, <NUM>° or more and <NUM>° or less. That is, the first link second end 91b at the start of the transverse sealing operation is positioned below the top dead center T an amount corresponding to a rotation angle of <NUM>° or more.

In the second phase of the first cycle, the first link <NUM> rotates in the forward direction R so that the angle θ reaches a value θ<NUM>. The value θ<NUM> is less than at least <NUM>°, and the first link second end 91b is above the bottom dead center B. The value θ<NUM> is, for example, <NUM>° or more and <NUM>° or less. That is, the first link second end 91b at the end of the transverse sealing operation is positioned above the bottom dead center B an amount corresponding to a rotation angle of <NUM>° or more.

In the third phase of the first cycle, the first link <NUM> stops. At this time, the first sealing jaw <NUM> and the second sealing jaw <NUM> move away from each other. Alternatively, the first link <NUM>, instead of stopping, rotates slightly further in the forward direction R. At this time, the first sealing jaw <NUM> and the second sealing jaw <NUM> move away from each other while moving in the conveyance direction of the film tube FT, that is, downward.

In the fourth phase of the first cycle, the first link <NUM> rotates in the reverse direction -R.

As described above, in the first control, the operation during one cycle includes both a rotation of the rotating shaft 59a in the forward direction R and a rotation of the rotating shaft 59a in the reverse direction -R.

In the second cycle, the first link <NUM> operates in exactly the same way as in the first cycle.

The second control is control that performs one of one transverse sealing operation and the subsequent transverse sealing operation with a forward rotation of the rotating shaft 59a and the other with a reverse rotation of the rotating shaft 59a. <FIG> is a schematic diagram showing the operation of the first link <NUM> under the second control in two cycles.

In the third phase of the first cycle, the first link <NUM> rotates further in the forward direction R. At this time, the first sealing jaw <NUM> and the second sealing jaw <NUM> move away from each other while moving in the conveyance direction of the film tube FT, that is, downward.

In the fourth phase of the first cycle, the first link second end 91b moves to the second half circle h2. The first link <NUM> rotates further in the forward direction R.

At the start of the first phase of the second cycle, the first link second end 91b is in the second half circle h2. The angle θ of the first link <NUM> is set to an initial value θ<NUM>. The initial value θ<NUM> is less than at least <NUM>°, and the first link second end 91b is below the top dead center T. The initial value θ<NUM> is, for example, <NUM>° or more and <NUM>° or less. That is, the first link second end 91b at the start of the transverse sealing operation is positioned below the top dead center T an amount corresponding to a rotation angle of <NUM>° or more.

In the second phase of the first cycle, the first link <NUM> rotates in the reverse direction -R so that the angle θ reaches a value θ<NUM>. The value θ<NUM> at least exceeds <NUM>°, and the first link second end 91b is above the bottom dead center B. The value θ<NUM> is, for example, <NUM>° or more and <NUM>° or less. That is, the first link second end 91b at the end of the transverse sealing operation is positioned above the bottom dead center B an amount corresponding to a rotation angle of <NUM>° or more.

In the third phase of the second cycle, the first link <NUM> rotates further in the reverse direction -R. At this time, the first sealing jaw <NUM> and the second sealing jaw <NUM> move away from each other while moving in the conveyance direction of the film tube FT, that is, downward.

In the fourth phase of the first cycle, the first link second end 91b moves to the first half circle h1. The first link <NUM> rotates further in the reverse direction -R.

As described above, in the second control, a transverse sealing operation accomplished by a rotation of the rotating shaft 59a in the forward direction R and a transverse sealing operation accomplished by a rotation of the rotating shaft 59a in the reverse direction -R are alternately performed.

(<NUM>-<NUM>)
The control unit <NUM> can perform the first control and the second control. Consequently, there is greater flexibility in the operations that the bag-making and packaging machine <NUM> executes.

(<NUM>-<NUM>)
The vertical link mechanism <NUM> has the first link <NUM> and the second link <NUM>. Consequently, the rotational force of the rotating shaft 59a can be transmitted by the first link <NUM> and the second link <NUM> to the first sealing jaw <NUM> and the second sealing jaw <NUM>.

(<NUM>-<NUM>)
At the end of the transverse sealing operation, the first link second end 91b is not positioned at the bottom dead center B. Consequently, the operation subsequent to the transverse sealing operation can be smoothly started.

(<NUM>-<NUM>)
At the start of the transverse sealing operation, the first link second end 91b is not positioned at the top dead center T. Consequently, the transverse sealing operation can be smoothly started.

(<NUM>-<NUM>)
At the start of the transverse sealing operation, the first link second end 91b is positioned above the bottom dead center B an amount corresponding to a rotation angle of <NUM>° or more. Consequently, the first sealing jaw <NUM> and the second sealing jaw <NUM> can move further downward at the end of the transverse sealing operation, so jamming of the film F that is conveyed can be inhibited.

(<NUM>-<NUM>)
At the start of the transverse sealing operation, the first link second end 91b is positioned below the top dead center T an amount corresponding to a rotation angle of <NUM>° or more. Consequently, speed in the vertical direction for the first sealing jaw <NUM> and the second sealing jaw <NUM> to perform a stripping operation can be ensured.

(<NUM>-<NUM>)
The forward rotation and the reverse rotation of the rotating shaft 59a are each executed one time each for every two transverse sealing operations. Consequently, the frequency of switches between the forward rotation and the reverse rotation is small, so the transverse sealing operation can be quickly performed.

(<NUM>-<NUM>)
The first link second end 91b moves downward after the end of the transverse sealing operation. Consequently, jamming of the film F that is conveyed can be inhibited.

(<NUM>-<NUM>)
According to this configuration, the control unit is capable of executing both the first control and the second control. Consequently, control flexibility is improved.

Claim 1:
A bag-making and packaging machine (<NUM>) comprising:
sealing jaws (<NUM>, <NUM>) configured to perform a transverse sealing operation;
a horizontal moving device (<NUM>) configured to move the sealing jaws (<NUM>, <NUM>) in a horizontal direction;
a vertical moving device (<NUM>) configured to move the sealing jaws (<NUM>, <NUM>) in a vertical direction; and
a control unit (<NUM>),
wherein the vertical moving device (<NUM>) has
a rotating shaft (59a) capable of forward rotation and reverse rotation,
a motor (<NUM>) configured to rotate the rotating shaft (59a), and
a link mechanism (<NUM>) configured to transmit rotational force of the rotating shaft (59a) to a support body (<NUM>) that supports the sealing jaws (<NUM>, <NUM>) such that the support body (<NUM>) and the sealing jaws (<NUM>, <NUM>) move in the vertical direction,
wherein the control unit (<NUM>) is configured to perform:
a first control that forwardly rotates and reversely rotates the rotating shaft (59a) during the time from the start of one transverse sealing operation to the start of the subsequent transverse sealing operation;
characterised in that the control unit (<NUM>) is further configured to perform:
a second control that performs one of one transverse sealing operation and the subsequent transverse sealing operation with a forward rotation of the rotating shaft (59a) and the other with a reverse rotation of the rotating shaft (59a), and
in that the control unit (<NUM>) is configured to selectively perform one of the first control and the second control.