JPS6231381Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an improvement of a device for detecting the end of a roll film used in a packaging machine or the like.

Conventionally, the end of the film roll used in packaging machines was detected by a limit switch placed in engagement with a vertical curtain, and continuous wrapping operations were made possible by connecting it to a spare film roll. Detection of the end of the film has become extremely uncertain due to malfunction of the limit switch due to shaking of the film curtain, etc.

In the present invention, a detection device with a guide plate consisting of two conductors pressed with a weak elastic force is swingably arranged on the side of the film path, and the detection device is normally retracted to the side of the film path. Also, when the remaining amount of film reaches around a predetermined value, the film is swung and held in response to a signal from a warning detector.
It is possible to detect the passage of the trailing edge of the film by the conduction of two conductors, and it reliably detects the trailing edge of the film without being affected by the shaking of the film curtain, thereby eliminating the defects of the conventional device described above. The purpose of the present invention is to provide a device for detecting the end of a film.

To describe in detail the embodiment of the packaging machine shown in the figure, 1, 2
A film roll and a preliminary film roll are rotatably supported by rollers 3, 4 and 5, 6, respectively. Of these, rollers 3 and 5 are pivotally supported at the tips of brackets provided at the fixing part of the packaging machine, and roller 6 is attached to one arm of a T-shaped arm 7 whose central portion is swingable concentrically with roller 5. The roller 4 is pivotally supported at the tip of the other arm of the T-shaped arm 7, and the link 9 has one end pivoted to the packaging machine fixing section. I've let it happen.

Numeral 10 is a stopper provided on the packaging machine fixing part so as to be able to engage with the tip of the T-shaped arm 7, and 11 is a stopper whose base is pivotally connected to the packaging machine fixing part and whose tip end is pivotally connected to the tip of the leg of the T-shaped arm 7. When the cylinder 11 is retracted, the tip of the T-shaped arm 7 engages with the stopper 10 and the rollers 3, 4 and 5, 6
are placed in a horizontal state, and the rollers 5 and 6 are positioned appropriately above.

As a result, the T-shaped arm 7 swings clockwise in FIG. 1 due to the extension of the cylinder 11.
First, the roller 4 moves to the left in the figure to drop the core tube of the used film roll 1, and then the roller 6 becomes higher than the roller 5, causing the spare film roll 2 to roll to the right in the figure. The next spare film roll is mounted between the rollers 5 and 6 when the cylinder 11 is in the returned state.

Reference numeral 12 indicates a core tube holder for the film roll, and reference numeral 13 indicates an advance notice detector provided below the roller 3, which detects when the diameter of the film roll 1 has decreased to a predetermined value (diameter when the remaining amount of film is small) due to use. Detects this and sends an appropriate message.

Reference numeral 14 denotes a film, which includes a vertical curtain portion 14a, a holding portion formed by a feed roller 15 with a driving device and a pinch roller 16, a guide roller 17, and a dancer roller 1.
8. It reaches the packaging position via guide rollers 19, etc., and is maintained in an appropriate tension state by the driving force of the feed roller 15 corresponding to the pulling force of the packaged item at the packaging position, so that it can be pulled out from the film roll 1. .

Reference numeral 20 denotes a heat fusing device provided above the film vertical curtain portion 14a, and a movable portion 23 comprising a fixing portion 21 and a cylinder 22 located on both sides of the film.
Consists of.

The fixing part 21 is equipped with a needle-shaped film stopper 24 that projects upward, and fixes the tip of the film 25 pulled out from the preliminary roll 2. When the cylinder 22 is extended, the film is fixed. It looks like 14 and 25 are heat fused together.

Reference numeral 26 denotes a detection device with a guide plate disposed on the side of the vertical film curtain portion 14a below the heat-sealing device 20, and has the following configuration.

That is, 27 is an angle member fixed to the packaging machine fixing part 28, and a rotation drive source 29 is fixed to the back side of the vertical member parallel to the film curtain 14a, and an arm base 30 is attached to the rotation shaft 29a of the drive source 29. The key is locked. Reference numerals 31 and 32 designate guide plates that protrude in the radial direction from the arm base 30 at appropriate intervals, and are wide on one side at the tip and bent outward from each other to form an eight-shape shape.

33 is a spring plate, and the base end is an insulator 3 fixed with screws.
4 is capped on the outer surface of the arm base 30 and fastened with bolts, and a conductor 35 is fastened to the tip with screws so as to pass through a square hole 31a formed in the guide plate 31.

36 is an insulator fixed to the tip of the guide plate 32, and the guide plate 32 is connected to the guide plate 32 by a conductor screw 37 at the center inside.
The conductor 3 passes through the square hole 32a drilled in the
8 is fixed, and both conductors 35 and 38 are always pressed against each other by the weak elastic force of the spring plate 33.

Reference numeral 39 indicates the angle member 2 so as to be electrically conductive when the guide plate 32 swings from the vertical position to the horizontal position.
A limit switch 40 fixed to the side of 7 has one end connected to the conductor 35 and the other end connected to the conductor screw 37 via a power source 41, a transmitter 42, and a limit switch 39.
This is a conductor connected to the

The detector 13 rotates the rotational drive source shaft 29a by 90 degrees by the signal, and the limit switch 39 is activated.
In the operating state, the transmitter 42 sends a signal due to conduction between the conductors 35 and 38, causing the feed roller 15 to stop and the cylinder 22 to extend.As the cylinder 22 moves back and returns, the cylinder 11 extends. Each is configured so that the feed roller 15 rotates again upon return.

1, when the diameter of the film roll 1 decreases to a predetermined value due to the use of the film, the detector 13 is actuated by the lowering of the roll, and the rotation drive source 29 is actuated. As a result, the guide plates 31 and 32 swing together from the vertical position shown by the two-dot chain line in FIG. 2 to the horizontal position shown by the solid line in the same figure. At this time, the side part of the film vertical curtain 14a is guided by the guide plates 31, 32 and the notch openings formed in both the conductors 35, 38, and overcomes the weak elastic force of the spring plate 33 to , 38, both conductors are brought into a non-conducting state.

When the guide plate 31 is at the complete swing position, the limit switch 39 is activated, but the transmitter 42 is not activated due to the film being held.

Furthermore, film use is carried out, and film 14
When the terminal end of the cylinder passes between the two conductors 35 and 38, the transmitter 42 is activated due to the conduction between the two conductors, and the rotation of the feed roller 15 is stopped and the cylinder 22 is extended.

As a result, the film 14 and the film 25 are thermally fused together, and as the cylinder 22 subsequently returns, the cylinder 11 is extended, causing the remaining core cylinder of the film roll 1 to fall onto the core cylinder holder 12 below, and the preliminary roll. 2 is rolled between rollers 3 and 4. Next, when the cylinder 11 returns, the feed roller 15 is driven again to restart the packaging operation.

In the above description, the advance detection signal for detecting that the remaining amount of film has decreased and the end of the film is approaching is for detecting a decrease in the diameter of the film roll, but is not limited to this. It is also possible to use a device that detects a decrease in the weight of a film, or a device that is installed in a film stretching section or the like to detect the length of a passing film.

As described in detail above, in the device of the present invention, the film end detector is normally retracted to the side of the film curtain, but is swung to the film clamping position by the advance notice detector activated when the remaining amount of the film roll decreases. Since the heat fusion device and other devices are actuated by the transmission caused by the passage of the ends of the film of the two conductors constituting the film, the end of the film can be detected reliably without being affected by the shaking of the film curtain, etc. .

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is an overall layout, Fig. 2 is an enlarged view taken in the direction of the arrow in Fig. 1, and Figs. -, - A cross-sectional view and a side view. In the figure, 1 is a film roll, 3 and 4 are rollers,
Reference numeral 13 indicates a detector, 14a a vertical film curtain, 26 a detection device with a guide plate, 31 and 32 guide plates, 33 a leaf spring, 35 and 38 a conductor, and 42 a transmitter.

Claims (1)

[Claims for Utility Model Registration] (1) In a film roller having two rollers that are capable of pulling out a film upwardly from a film roll whose lower part is rotatably supported, the film path side in the vertical direction near the film roll. A detection device with a guide plate made of two conductors pressed against each other with a weak elastic force is arranged so as to be swingable from the side of the film path to the film path, and the remaining amount of film is reduced to near a predetermined amount. An advance notice detector for detecting the above is provided, and the detection device with a guide plate is always on standby at a retracted position on the side of the film path, and is swung by the signal from the advance notice detector to overcome the elastic force and nip the film. , above 2
1. A film end detection device, characterized in that it is possible to detect passage of a trailing end of the film by conduction between two conductors. (2) The film end detection device according to claim 1, wherein the advance notice detector is provided near the film roll and is capable of transmitting a signal when the film roll has decreased in diameter to around a predetermined diameter.