JPH0659893B2 - Label application device for rotary blow molding machine - Google Patents

Description

Detailed Description of the Invention [Technical Field] The present invention relates to a label application device for a rotary blow molding machine, and more particularly to a label application device for a rotary blow molding machine in which a label is placed on the inner wall of a pair of split molds that can be opened and closed and rotates on a circular track at a constant speed, and the label is fused to the molded product during blow molding.

BACKGROUND ART A rotary blow molding machine is known in which a large number of split mold units, each consisting of a pair of split molds that can be opened and closed along the horizontal axis, are installed at equal intervals around the outer periphery of a rotor that rotates around a horizontal axis, a parison is extruded between the open split molds, the split molds are then closed, and air is blown into the hollow part of the parison to form a hollow molded product.

Such rotary blow molding machines generally mold plastic containers. Labels indicating the contents of the plastic containers are attached to the plastic containers. However, if the label is attached to the molded container with an adhesive, a label attachment step is required after the blow molding step, which increases the manufacturing cost.
Another problem is that it is difficult to obtain strong adhesion between the label and the container, and therefore a method has been proposed in which a high-temperature molding material is pressed onto the label when the container is molded, thereby fusing the label to the container.

That is, the label application device shown in U.S. Pat. No. 4,479,770 has a dispensing head that reciprocates up and down between a label magazine and an open mold half, and an expandable label carrier is provided on the dispensing head, and the label is transferred from the label magazine to the inner wall of the mold half by a combination of the two reciprocating motions.

In such a label application device, the drive mechanism is complicated and the dispensing head is reciprocated over a long distance, so a drive force against inertia is required.

SUMMARY OF THE INVENTION An object of the present invention is to provide a label application device for a rotary blow molding machine which overcomes the above problems, requires a small driving force, and has a simple structure.

In a rotary blow molding machine, a pair of closed mold halves must be clamped together with a clamping force that overcomes the air pressure blown in, and a mold clamping device for this purpose is shown in U.S. Pat. No. 3,764,250.

In the mold clamping device shown there, a split mold holder that holds a pair of split molds is clamped by a fixed cam via a slider crank mechanism and a compression spring.

In the above-mentioned conventional mold clamping device, the cam follower that engages with the fixed cam must operate against the force of the compression spring, so a large force is required to drive the cam follower supported by the rotor, and the driving force of the rotor fluctuates greatly due to the fluctuating load of the cam follower, which in turn causes the rotational speed of the rotor to fluctuate, making it difficult to accurately position the label to be placed inside the split mold.

Furthermore, scrap, such as defective molded products, generated in the early stages of blow molding is disposed of in a work space located between the part where the split molds begin to separate and the device for removing the molded product (this work space is essential for the mechanism of the blow molding machine).

However, this work space is not necessary after the initial molding stage has passed and the molding state has reached a normal state. However, because the timing of the closing and opening of the split molds is controlled by a single shaped cam, the split molds open at the same time as in the initial molding stage even after the molding state has reached a normal state, which shortens the blow molding period after the molding state has reached a normal state (by reducing the rotation angle of the split piece unit in the closed state).

The present invention has been made to solve the above problems, and its object is to provide a label application device for a rotary blow molding machine that utilizes a mold clamping device in a rotary blow molding machine that has small fluctuations in the load that drives the rotor and a long blow molding period under normal conditions, and that accurately positions and places labels on the inner walls of the split molds, thereby producing high-quality molded products.

DISCLOSURE OF THE INVENTION In order to solve the above problems, the labeling device for a rotary blow molding machine according to the present invention has a rotor that rotates about a horizontal axis, and a number of two-split mold units, each consisting of a pair of split molds that can be opened and closed in the direction of the horizontal axis, are arranged at equal intervals around the outer periphery of the rotor that rotates about the horizontal axis, and a parison is extruded between the open split molds, and then the split molds are closed and air is blown into the hollow part of the parison to form a hollow molded product.In this labeling device for a rotary blow molding machine, a heat-sealable label is arranged on the inner wall of the split mold, and a high-temperature molding material is pressed onto the label to apply the label to the molded product.The labeling device for a rotary blow molding machine has a rotor that rotates a predetermined angle parallel to the rotation axis of the rotor and stops. A rotating shaft is provided which is rotated intermittently in one direction so as to rotate in one direction, and two parallel links to which a dispensing head is attached are provided on a lever holder fixed to the rotating shaft so as to be able to swing at an interval of 180° about the axis of the rotating shaft, and a segment gear provided on one of the parallel links is engaged with a rack provided on a slide block which slides on the rotating shaft which is rotated intermittently, and the parallel links are swung by sliding the slide block on the rotating shaft, and when the rotating shaft stops at the stop position, a rubber cup fixed to the dispensing head passes a label to the inner wall of the split mold.

By configuring the label placement device in this way to transport the label to the inner wall of the split mold by a combination of rotational and swinging motion, there is no need to reciprocate a heavy member over a long distance, which reduces the required driving force and makes the device smaller, as well as making it easier to operate at high speeds.

The mold clamping device used in the present invention has a pair of split mold holders, each of which holds a pair of left and right split molds, slidably held by a guide rod mounted on a rotor, one of the split mold holders being connected to a slider slidably supported on the guide rod via a hydraulic cylinder unit, and the other split mold holder being connected to a slider via a lever so as to move in the opposite direction to the slider, and the slider is connected to a cam follower that engages with a mold clamping control cam installed near the rotor, and a slider that is held by the rotor so as to be movable in the radial direction thereof and can take a dead center position. The hydraulic cylinder unit is connected via a slider crank mechanism, and when the slider crank mechanism is at its dead point, the hydraulic cylinder unit applies clamping pressure to the split mold holder. Therefore, no clamping force is applied to the slider crank mechanism that drives the split mold holder and the cam follower until the slider crank mechanism is at its dead point. When the hydraulic cylinder unit applies clamping force, the slider crank mechanism is at its dead point, so the clamping force is received by the fulcrum of the slider crank mechanism and no clamping force is applied to the cam follower.

Therefore, no large force is applied to the cam follower held by the rotor, the load on the rotor is constant and the rotor is driven at a constant speed, so that the label is accurately positioned on the inner wall of the split mold.

The mold clamping control cam is a fixed cam on the side that controls closing of the split mold and a movable cam on the side that controls opening, and the timing of opening the split mold is variable between the early stage of blow molding and the normal stage, so that a working space for processing scrap such as defective molded products that are generated in the early stage of blow molding is not required during normal blow molding.

In addition, a fixed cam for mold clamping hydraulic pressure is attached to the fixed cam, a movable cam for mold clamping hydraulic pressure is attached to the movable cam, the movable cam for mold clamping hydraulic pressure is made movable in synchronization with the movable cam for mold clamping hydraulic pressure, and the period of hydraulic pressure supply to the hydraulic cylinder unit is changed between the initial stage of blow molding and normal operation.

Therefore, at the beginning of blow molding, the movable cam is shortened to hasten the time when the split molds separate, and a working space for disposing of scraps such as defective molded products is provided between the part where the split molds start to separate and the molded product removal device.When blow molding is normal, the movable cam is extended so that this working space can be used for the blow molding period, and the time when the split molds separate can be extended, resulting in the production of high-quality molded products with labels affixed thereto.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram of a rotary blow molding machine using the present invention, FIG. 2 is a front view of the machine with a portion omitted, FIG. 3 is a right side view of the machine with a portion omitted, FIG. 4 is a front view of a mold clamping control cam of the machine, FIG. 5 is an explanatory diagram of the control cam at the beginning of blow molding, FIG. 6 is a front view of the control cam of the same, FIG. 7 is an explanatory diagram of the control cam during normal blow molding, FIG. 8 is a front view of the control cam of the same, FIG. 9 is a front view showing a partial cross section of a label placement device of the machine, FIG. 10 is a cross-sectional view taken along line X-X in FIG. 9, FIG. 11 is a cross-sectional view taken along line XI-XI in FIG. 9,
The figure shows the label take-out device used in the machine.
12. FIG. 13 is a cross-sectional view of the XII-XII line in FIG. 12.
14 is a view taken along the line XIV in FIG. 12; FIG. 15 is a schematic diagram showing the drive mechanism of a label placement device used in the machine; and FIG. 16 is a schematic diagram showing the drive mechanism of a label removal device used in the machine.

BEST MODE FOR CARRYING OUT THE INVENTION In order to more fully describe the present invention, reference will now be made to the specific embodiment illustrated in the accompanying drawings.

Figure 1 is a schematic diagram of a rotary blow molding machine using the present invention. In the figure, 1, 1... are split mold units, and a large number of them are mounted at equal intervals on the outer periphery of a rotor 7 (shown in Figure 2) that rotates around a rotary shaft 2. When the rotor passes through the illustrated rotation range S, each split mold 1a, 1a is closed, and when the rotor passes through other rotation ranges, each split mold 1a is opened. The opening and closing mechanism of the split mold unit 1 will be described later.

When the split molds 1a, 1a are closed, both ends of the hollow portion of the plastic tube extruded from the extrusion mold 3 between the left and right split molds 1a, 1a of each split mold unit 1, i.e., the parison, are sealed. Air is blown into the hollow portion from a blow needle provided in the split mold, and the parison is sealed inside the split molds 1.
a, 1a and pressed against the inner wall surfaces of the container to form the container shape.

Thereafter, the molded plastic is cooled on the inner wall surfaces of the split molds 1 a, 1 a through which cooling water passes, and becomes a molded product 8 .

When the plastic is pressed, it fuses and becomes one with the molded product 8.

When the split molds 1a, 1a are opened, first, the scrap parison remaining between the split mold units 1 (connecting the molded products) is blown into the scrub receiving port 6 with air, and then the molded product 8 is sucked and removed by the molded product removal device 5 and sent onto the belt conveyor.

Thereafter, labels are placed on the left and right inner wall surfaces of the opened split molds 1a, 1a by the label placement device 4. The mechanism of the label placement device 4 will be described later.
The label placed on the wall of the molded article 8 is fused and becomes one with the molded article 8 when hot plastic is pressed against it later. In this way, the molded article 8 with the label attached is produced during blow molding.

Next, the mechanism of the mold clamping device 37 will be described with reference to FIGS.

The rotation of the electric motor 9 is transmitted to a large gear 11 fixed to the rotary shaft 2 via a reducer 10, and the rotor 7 fixed to the rotary shaft 2 is rotated at a constant speed.

A mold clamping control cam (hereinafter referred to as cam) 26 is attached to the machine frame on the right side surface of the rotor 7, and a cam follower 25 that engages with the cam 26 is axially attached to a slide block 24 that slides in the radial direction of the rotor on a guide 23 fixed to the rotor 7. In this way, the slide block 24 reciprocates in the radial direction as the rotor 7 rotates.

The slide block 24 further includes a pin 22 and a link 2
The rotor 7 is connected to one end of a lever 18, the center of which is supported by a pin 19 on the rotor 7, via a pin 21, to swing the lever 18. The other end of the lever 18 is connected to a pin 17,
The slider 14 is connected to the link 15 and the pin 16. The slider 14 is slidably supported on a guide rod 35 mounted on the outer periphery of the rotor 7, and constitutes a slider crank mechanism together with the lever 18 and the link 15. That is, the slider 14 moves linearly on the guide rod 35 as the lever 18 rotates.

The slider 14 also includes a pin 27, a rod 28, and a pin 2
9, a lever 30, a pin 32, a link 33, and a pin 34 are connected to one of the split mold holders 13, and the center of the lever 30 is supported by a pin 31 on the rotor 7.
Since both ends of the lever 30 change the direction of movement, the slider 14 and the split mold holder 13 move in opposite directions.

The other split mold holder 12 is connected to the slider 14 via a hydraulic cylinder unit 36 attached to the slider 14, and moves in the same direction as the slider 14. In other words, the split mold holders 12 and 13 are driven to move toward or away from each other. Split molds 1a, 1a are attached to these split mold holders 12, 13. Clamping pressure is applied to the split molds 1a, 1a by operation of the hydraulic cylinder unit 36.

The hydraulic cylinder unit 36 is a type in which the piston rod is pushed out when oil is injected into the cylinder, and the piston rod is pulled back into the cylinder by the action of a spring built into the cylinder when the pressure in the pipe leading to the cylinder drops.
Oil is injected into or discharged from rotor 6 by three-way valves (not shown) arranged on rotor 7 in the same number as the number of split mold units 1. Supply pipes and discharge pipes to the three-way valves are joined together, pass through the inside of rotating shaft 2, and are connected to a hydraulic pump and an oil tank via a rotary joint.
The three-way valve is operated by an actuator located near the rotor 7 .

Then, the link 15 and lever 18 of the slider crank mechanism are aligned via pins 16, 17, 19, and 21 as shown in the lower part of Fig. 2 (dead center position), and when the split mold holders 12 and 13 approach, the three-way valve is operated by the actuator and high-pressure oil is injected into the hydraulic cylinder unit 36. At this time, the piston rod is pushed out and the split molds 1a and 1b attached to the split mold holders 12 and 13 are pressed against each other.
This clamping pressure is applied to pin 19
is received by the cam follower 25 and is not transmitted to the cam follower 25.

Immediately before the split molds 1a, 1a are opened, the three-way valve is operated by the actuator, and when the inside of the hydraulic cylinder unit 36 is connected to the discharge pipe, the piston is pushed back by the spring in the hydraulic cylinder unit 36, discharging the oil in the cylinder, and the piston rod is pulled in, releasing the mold clamping pressure. In this state, the split molds 1a, 1a are opened by the action of the cam 26 and cam follower 25 as shown in the upper part of Figure 2, but since the mold clamping pressure is not transmitted to the cam 26 and cam follower 25, the contact pressure is small.

Next, the structure of the cam 26 will be described with reference to FIG.

As described above, the cam 26 controls the closing and opening/closing timings of the split dies 1a, 1a. The cam 26 is made up of a fixed cam 26a attached to the machine frame c and controlling the closing timing, and a movable cam 26b that rotates opposite one side of the fixed cam 26a by the operation of a cam drive hydraulic cylinder 112 whose base is journaled on the machine frame c and controls the opening timing.

The fixed cam 26a is provided with a fixed cam 2 for clamping hydraulic pressure.
A mold clamping hydraulic pressure movable cam 26d is attached to the movable cam 26b so as to move in synchronization with the movable cam 26b.

FIG. 5 is an explanatory diagram showing the state of the cam 26 at the beginning of blow molding, in which the cam drive hydraulic cylinder 112 is not in operation, and the movable cam 26b and the mold clamping hydraulic movable cam 26d rotate due to the retraction of the piston rod, and the fixed cam 26a
The rotation angle of the split mold unit 1 for blow molding from the time X when the split molds 1a, 1a are closed, which is controlled by the movable cam 26d, to the time Y when the split molds 1a, 1a start to separate, which is controlled by the movable cam 26d, is small (for example, 175°).
The valve 113 for clamping hydraulic pressure is controlled by the movable cam 26c and the movable cam 26d.

FIG. 6 shows the cam 2 at the initial stage of blow molding as explained in FIG.
6 shows the shape of

FIG. 7 is an explanatory diagram showing the state of the cam 26 when the initial stage of blow molding has passed and the molding state has reached a normal state. The cam drive hydraulic cylinder 112 is operated, and the piston rod is extended, causing the movable cam 26b and the mold clamping hydraulic movable cam 26c to move.
6d rotates, and the split molds 1a, 1b are controlled by the fixed cam 26a.
The rotation angle of the split mold unit 1 for blow molding is increased from the time X when the split molds 1a and 1a are closed to the time Y when the split molds 1a and 1a start to separate, which is controlled by the movable cam 26b.
05°), as mentioned above, the working space for disposing of scraps such as defective molded products in the initial stage of blow molding is used during the blow molding period.

FIG. 8 shows the shape of the cam 26 during the normal blow molding period explained in FIG.

Next, the mechanism of the label placement device 4 will be described with reference to FIGS. 9 to 11 and 15.

The label placement device 4, which places labels on the inner walls of the opened mold halves 1a, 1a, is attached to a rotary shaft 40 and rotates together with the rotary shaft 40 as shown in FIG.

The rotating shaft 40 is driven to rotate by the drive unit shown in Figure 15, and the rubber cups 51, 51... arranged at the tip of the link 49 rotate in one direction, repeatedly stopping at a position facing the label take-out device 80, 80 or the inner wall of the split mold 1a, 1a (the position shown in Figure 9) and rotating 180 degrees.

It should be noted that four, three or two rubber cups 51 may be provided at equal intervals, so the above 180° includes 90° and 120°.

The shaft 74 of the drive device is driven so as to rotate once while the split mold unit 1 is pitch fed, and the rotation of this 74 is transmitted by a Geneva stop mechanism 75 so that when the shaft 74 rotates once, the shaft 73 rotates 90° and then stops.

The rotation of the shaft 73 is transmitted to the rotary shaft 40 by the gears 72 and 71 at a rotational speed ratio of 1:2.

That is, the rubber cups 51, 51... are
When the split mold 1a passes the position shown in FIG.
It will occupy a position facing the inner wall of the

As shown in FIG. 9, the links 42 and 49, the lever holder 4
1 and the dispensing head 50 are connected to the pins 43, 43.
... to form four parallelogram links. The lever holder 41 is fastened to the rotating shaft 40 so as to be integral with it.

A segment gear 44 fixed to the base end of the link 42
The lever 41 engages with a rack 46 fixed to the slide block 45, and when the slide block 45 moves in the axial direction of the rotation shaft 40, the link 42 supported by the lever holder 41 swings around the pin 43.
As shown in FIG. 10, the rotor 5 is supported by a rotary shaft 40 so as to be constrained in the rotational direction and slidable in the axial direction.

The link 49 is biased toward the center by a tension spring 52, and the cam follower 47 provided on the slide block 45 is biased toward the center by a cam 48 fixed to the split molds 1a, 1a.
When the slide block 45 is pressed, the slide block 45 moves toward the center and swings the link 42 outward via the rack 46 and the segment gear 44. At this time, as will be described later, the label 67 adsorbed on the rubber cup 51 is pulled into one of the split molds 1.
a) is placed on the inner wall of the

An air suction hole is opened in the inner wall of each split mold 1 a, and the label 67 is held and welded to the plastic molded product 8 .

At a position above the rotating shaft 40, the parallelogram link is supported in a fixed position by the cam follower 47 engaging with a cam 66 fixed to a bearing device that supports the rotating shaft 40, and receives a label 67 from a label take-out device 80.

The dispensing head 50 delivers the label 67 by vacuum suction and compressed air blowing.
As shown in FIG. 0, two rubber cups 51, 51 and an air ejection nozzle 68 are provided, and the rubber cups 51, 51 are connected to a vacuum pump via flexible hoses 59, 60, an electromagnetic valve 55 and a rotary joint 64, and the air ejection nozzle 68 is connected to a compressed air tank via a flexible hose 62, an electromagnetic valve 56 and a rotary joint 65.

In order to apply labels 67 to the front and back of the molded product 8, a front label dispensing head and a back label dispensing head are provided on the same side of the rotating shaft 40, and their rubber cups are connected to solenoid valve 55 via flexible hoses 57 and 58, and their air ejection nozzles are connected to solenoid valve 56 via flexible hose 61. However, a different solenoid valve is connected to the dispensing head on the opposite side of the rotating shaft 40.

These flexible hoses are fixed to the rotary shaft 40 via blocks 53 and 54 as shown in Fig. 11, and communicate with the solenoid valves through the hollow holes in the rotary shaft 40. These solenoid valves are opened and closed by the current flowing through the slip rings 63 (Fig. 9), and the current flowing through the solenoid valves is controlled based on the signal from the rotation angle sensor of the rotor 7.
The dispensing head 50 is connected to the label pick-up device 80.
When the label 67 is received from the mold half 1a, the label 67 is sucked by the rubber cup 51, and when the label 67 is placed on the inner wall of one of the mold halves 1a, air is blown onto the label 67 by the air jet nozzle 68.

Next, the label take-out device 80 will be described with reference to FIGS. 12 to 14 and 16. FIG.

The frame 81 is supported by a shaft 82 and a drive shaft 83 and rotates intermittently by 180°, and the shaft 96 rotates back and forth once while the drive shaft 83 is stopped.

The operation of the label take-out device drive device 84 which drives the shaft 96 and the drive shaft 83 will be described with reference to FIG.

The shaft 85 is driven so as to rotate once while the split mold unit 1 is fed one pitch, and the rotation of this shaft 85 is transmitted by a Geneva stop mechanism 86 and gears 88 and 89 so that when the shaft 85 rotates once, the shaft 83 rotates 180° and then stops. The rotation of the shaft 85 is also transmitted by a Geneva stop mechanism 87 and gears 90 and 91 so that when the shaft 85 rotates once, the shaft 9
2 is rotated 360 degrees and then stopped. Moreover, shaft 92 rotates while drive shaft 83 is stopped.

The drive shaft 83 stops at the position where the frame 81 fixed thereto is positioned as shown in Figs. 13 and 14, that is, where the rubber cups 109, 109 of the label take-out device face the label magazine 111 and the label placement device 4. While the drive shaft 83 is stopped, the shaft 9
6 is connected to links 93, 94, 95 and pin 9 by shaft 92.
8, 99 and rotates back and forth once.

As shown in FIG. 14, a pair of opposing shafts 100, 10
The levers 101, 101 are fixed at their centers to the connecting rods 102, 102 to form a parallelogram link.
As shown in the figure, the levers 101 are rotatably supported by the frame 81 and guide rod stays 108, 108, and the levers 101, 101 are biased in the same direction by tension springs 103, 103.

As described above, when the shaft 96 rotates back and forth once, the lever 97 fixed thereto swings once between the position shown by the solid line and the position shown by the two-dot chain line in FIG.

At this time, the lever 101 is pushed and swings, and the shafts 100 and 10
When this occurs, the levers 104, 104 fixed to the shafts 100, 100 swing, causing the cam followers 175, 105 engaged therewith to reciprocate.

The cam followers 105, 105 are connected to the slide block 10
6, 106, and the slide block 10
The slide blocks 106 and 106 are further supported slidably on guide rods 107 and 107 supported by guide rod stays 108 and 108, so that the slide blocks 106 and 106 reciprocate together with the swinging of the levers 104 and 104.

At this time, the rubber cups 109, 109 provided on the slide blocks 106, 106 and the air ejection nozzle 11
0, 110 receives the label 67 from the label magazine 111 and delivers the label 67 to the label placement device 4, and the control of the solenoid valve (not shown) for this purpose is the same as that of the label placement device 4.

The rubber cup 109 that has received the label 67 from the label magazine 111 in this way is then guided to the label placement device 4 when the frame 81 rotates 180° in the direction of the arrow in FIG.
When the slide block 106 next moves back and forth, it delivers the label 67 to the label placement device 4.

In the mold clamping device of the above specific example, the slider crank mechanism for mold clamping is configured by configuring the split mold holder as a slider, converting the movement of this split mold holder into movement in the opposite direction using a lever, and transmitting this to a slider facing the split mold holder.The same effect can also be obtained by placing a hydraulic cylinder unit between this slider and the other split mold holder.

Industrial Applicability: The plastic containers manufactured by the apparatus of the present invention have labels fused to the container at high temperatures. If the label material is the same as the container material, a strong bond can be obtained, making them suitable for food containers. Furthermore, if the container and label are made of the same material, the container is reinforced by the label, thereby saving material for the container. In addition, the label is accurately positioned and attached to the container, resulting in a desirable product appearance.

Furthermore, because the mold clamping control cam consists of a fixed cam (for controlling the closing timing of the split mold) and a movable cam (for controlling the opening timing of the split mold), the working space required for scrapping defective molded products, which is required in the early stages of blow molding, can be used during the period when the blow molding is in a normal state, improving the cooling effect during molding and enabling the production of high-quality molded products, as well as allowing the incorporation of a label application device without reducing the mold clamping rotation angle of the split mold unit.

In addition, when checking the installation of the mold, the clamping of the mold, the cutting of the scrap parison, etc., the work must be done in the area of the movable cam.
This allows checking the mold clamping position without rotating the rotor.
A significant improvement in workability is achieved.

Claims (7)

[Claims] Claim 1: A rotor rotating around a horizontal axis has a rotor circumferentially extending from the rotor.
a rotary blow molding machine in which a plurality of split mold units each consisting of a pair of split molds that can be opened and closed in the horizontal axis direction are arranged at equal intervals, a parison is extruded between the open split molds, and then the split molds are closed and air is blown into the hollow portion of the parison to form a hollow molded product; and a heat-sealable sieve is arranged on the inner wall of the split mold of the rotary blow molding machine.
In a label application device for a rotary blow molding machine, which presses a high-temperature molding material onto the label to apply the label to the molded product, a rotating shaft is provided that is parallel to the rotating shaft of the rotor and is intermittently rotated in one direction so as to rotate a predetermined angle and then stop, and a lever holder fixed to the rotating shaft is provided with:
A label application device for a rotary blow molding machine is configured such that two parallel links to which a dispensing head is attached are arranged to be swingable at an interval of 180 degrees about the rotation axis, a segment gear provided on one of the parallel links is engaged with a rack provided on a slide block that slides on the rotation axis that is intermittently rotated, the parallel links are swung by sliding the slide block on the rotation axis, and a rubber cup fixed to the dispensing head passes a label to the inner wall of a split mold when the rotation axis stops. [Claim 2] A label application device for a rotary blow molding machine as described in claim 1, wherein a rubber cup fixed to the dispensing head is configured to receive a label from a label removal device that removes a label from a label magazine at a stop position of the intermittent rotational motion. 3. A label application device for a rotary blow molding machine according to claim 1, wherein said two parallel links form a symmetrical pair. [Claim 4] A pair of split mold holders for holding left and right split molds respectively are slidably supported on guide rods mounted on a rotor, one of the split mold holders is connected to a slider slidably supported on said guide rod via a hydraulic cylinder unit, the other split mold holder is connected to a slider via a lever so as to move in the opposite direction to the slider, and the slider is connected to a cam follower that engages with a mold clamping control cam installed near the rotor,
4. A label application device for a rotary blow molding machine according to claim 1, further comprising a mold clamping device that is held on the rotor so as to be movable in the radial direction thereof and is connected to the rotor via a slider crank mechanism that can assume a dead center position, and that applies mold clamping pressure to the split mold holder by the hydraulic cylinder unit when the slider crank mechanism assumes the dead center position. [Claim 5] A label application device for a rotary blow molding machine as described in Claim 4, wherein the mold clamping control cam is a fixed cam on the side that controls closing of the split mold and a movable cam on the side that controls opening, making the timing of opening the split mold variable. 6. The method according to claim 4, wherein the fixed cam is fixed to the frame of the rotary blow molding machine, and the movable cam is operated by a cam drive hydraulic cylinder whose base is journaled on the frame.
6. A label application device for a rotary blow molding machine according to claim 5. 7. A fixed cam for clamping hydraulic pressure is attached to the fixed cam, and a movable cam for clamping hydraulic pressure is attached to the movable cam,
A label application device for a rotary blow molding machine according to any one of claims 4 to 6, wherein the movable cam for mold clamping hydraulic pressure is movable in synchronization with the movable cam for mold clamping, and the period of hydraulic pressure supply to the hydraulic cylinder unit for mold clamping is variable.