JPH11952A - Impulse sealer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make precision of a cut length of a heating wire unnecessary while it can be easily changed to be strung by a method wherein a plurality of chuck pieces are provided inside a sleeve moving with engagement of a screw thread, and a support block is, in a free advance and retreat manner, fitted to a specific position. SOLUTION: One end of a heating wire cut out by an appropriate length is fixed to one side edge of a seal stand. A support block 6 is advanced, and the other end of the heating wire is inserted into a chuck mechanism. By retreating a sleeve 52 on a terminal main body 51 by rotating a sleeve 52, a chuck piece 53 is fastened, held, and the support block is retreated. Thereafter, a suitable tension is always applied to the heating wire with repulsive force of a spring or air pressure of an air cylinder, and a slack is prevented. Since executing holding in of the heating wire after advancing a movable terminal part to a suitable position in holding the chuck mechanism of the heating wire, the heating wire can be easily fitted even by an operator of weak force.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an impulse sealer used for heat sealing and fusing a plastic sheet.

[0002]

2. Description of the Related Art For example, when manufacturing a bag from a plastic film, in many cases, a method in which the film is folded in two and continuously supplied to a bag making machine, and heat sealing is performed at regular intervals and at the same time, fusing is performed. Has been adopted. An apparatus for performing such welding and / or fusing includes an impulse sealer having a structure as shown in FIG. 1, that is, a seal bar (2) on a plastic sheet (not shown) on a seal base (1). It is preferable that the heating wire (3) is supplied with electricity at the moment of falling to generate heat, thereby performing welding or fusing.

[0003] Normally, a nichrome wire is used as the heating wire. However, the heating wire is not limited to the nichrome wire, but expands when the temperature rises due to heat generation.
Therefore, one is a fixed terminal part (4) and the other is a movable terminal part (5). This movable terminal part is placed on an insulating block (6) as shown in FIG. Terminal
(5) A structure in which (31) is fixed together with a lead (8) and a terminal (81) from a power source with a screw (82) and the whole is pushed by a spring (7) (biased rightward in the figure) (5A) The tension always acts on the heating wire (3) to prevent it from sagging.

However, in order to form a terminal having such a structure, a spring having a considerably strong repulsive force must be used, so that a large force is required to extend the heating wire. Many of the heat seal workers were women, and felt that it was difficult to replace the heating wire.

Another problem is that in the above structure, the heating wire is cut to a fixed length and terminal pieces are attached to both ends, and at this time, the cutting length of the heating wire requires a considerably high precision. That is. If the length is longer than the standard length, there is a risk that the heating wire will sag due to insufficient tension by the spring.On the contrary, if it is too short, it will have to be installed against the repulsive force of the spring, and the above-mentioned difficulties will occur. In addition, the heating wire is easily cut.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problem associated with the replacement of the heating wire often seen in the conventional impulse sealer, so that even a worker having a weak force can easily replace the heating wire. An object of the present invention is to provide an impulse sealer that does not require exceptional precision in the cutting length of a heating wire.

[0007]

The impulse sealer of the present invention is an impulse sealer for welding and / or fusing a plastic sheet by instantaneously energizing a heating wire to generate heat. As shown in the figure, a movable terminal portion (5B) for fixing the heating wire (3) under tension, a cylindrical terminal body (51) having an external thread at one end, and a female thread engaged with the external thread are provided inside. From a sleeve (52) whose inner diameter decreases toward one end, a plurality of radially divided chuck pieces (53) inside the sleeve, and an insulating support block (6) for supporting the terminal body. And a support block is mounted at a predetermined position on the seal base so as to be able to move forward and backward.

In FIG. 3, reference numeral (81) denotes a terminal of a lead (8) connected to a power source, and (82) denotes a set screw thereof. When the sleeve (52) is rotated with respect to the terminal body (51) by the engagement of screws (to the right in FIG. 3), the chuck piece (5
3) is clamped and the heating wire (3) is added. Although not shown, between the chuck pieces (53), if springs that generate repulsive forces are embedded, the gaps between the chucks are opened as the sleeve moves (to the left in the figure). It becomes easy to insert the heating wires (3) at their centers. Since such a chuck mechanism is frequently used in a drill tip holding mechanism of an electric drill, for example, it can be easily manufactured by applying technology in the field.

In the impulse sealer of the present invention,
In use, it is necessary to always apply tension to the heating wire, and in order to urge the support block in the retreating direction, a spring may be provided similarly to the conventional one. In order to hold the heating wire with the chuck mechanism, it is necessary to advance the support block. To advance the support block against the force of the spring described above, a screw /
It is advantageous to use a nut mechanism or to use a lever mechanism (neither shown). Thus, the support block can be easily advanced with a small force.

The same effect can be obtained by using an air cylinder, and an appropriate tension can be applied to the heating wire by using air pressure, which is a recommended mode.

[0011]

When replacing the heating wire, first, one end of the heating wire cut to an appropriate length is fixed to one edge (left side in FIG. 1) of the seal base. Next, the support block (6) is advanced, and the other end of the heating wire is inserted into the above-mentioned chuck mechanism as shown in FIGS. 3 and 4, and the sleeve (52) is turned to rotate the terminal body (51). By retracting upward, the chuck piece (53) is clamped and held as shown in FIGS. 5 and 6, and then the support block is retracted. Thereafter, an appropriate tension is always applied to the heating wire by the repulsive force of the spring or the air pressure of the air cylinder, so that even if the heating wire is expanded and expanded by instantaneous energization, no slack occurs.

In the impulse sealer of the present invention, when the chucking mechanism of the heating wire is held, the movable terminal portion is advanced to a convenient position by a screw / nut or lever mechanism or by operating an air cylinder, and then the heating wire is heated. Since the holding is performed, even a weak worker can easily attach the heating wire.

When the heating wire is cut from a long one, there is no problem if the heating wire is too long and it can be absorbed into the terminal portion main body, except when the heating wire is too short and the holding margin is insufficient. The most reliable method is to cut off unnecessary parts after attaching the heating wire. For example, as shown in FIG. 7, a hole (83) is formed in the center of a set screw (82) of a terminal (81) of a lead (8) for connecting a terminal body to a power supply, and a heating wire is formed in the hole (83). 83)
Then, when the reheating can be performed, the heating wire can be easily cut by cutting the heating wire with a nipper or the like at a portion coming out of the set screw (82). When the heating wire is passed through the hole (83) from the front to the rear of the chuck mechanism, the tip of the set screw (82) may be recessed like a sliver.

If the heating wire can be passed through the hole (83) from the head of the set screw (82), that is, from the rear of the chuck mechanism, the recess at the tip of the set screw (82) is unnecessary, but each chuck piece is not required. The back of (53) should be cut diagonally to make it easier for the heating wire to exit forward. Passing the heating wire from behind allows the long heating wire wound on the reel to be supplied as it is and cuts off only the amount used. Waste is eliminated, which is preferable in increasing the utilization rate of the material.

If a spring is used, the forward position of the support block must be properly selected so that the repulsive force thereof becomes a predetermined value, and if the heating wire is maintained at that position so as not to slack, it is naturally appropriate. High tension is applied. If the tension can be determined by the air pressure of the air cylinder, the tension applied to the heating wire can be made substantially constant by adjusting the air pressure, even if the holding position is not always constant, so that the replacement is easier.

[Brief description of the drawings]

FIG. 1 shows a basic configuration of an impulse sealer.
The figure seen from the flow direction of the sealing material.

FIG. 2 is an expanded side view showing a structure of a movable terminal portion of a heating wire in a conventional impulse sealer.

FIG. 3 is a longitudinal sectional view showing a structure of a movable terminal portion of a heating wire of the impulse sealer according to the present invention, showing a stage before adding the heating wire.

FIG. 4 is a transverse cross-sectional view taken along the line II of FIG. 3;

FIG. 5 is a view of the movable terminal portion of the heating wire in FIG. 3 after the heating wire is added.

FIG. 6 is a cross-sectional view taken along the line II-II of FIG.

FIG. 7 is a longitudinal sectional view showing another aspect of the movable terminal portion of the heating wire shown in FIG. 3;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Seal base 2 Seal bar 3 Heating wire 31 Heating wire terminal 4 Fixed terminal part 5 Movable terminal part 5A Conventional movable terminal part 5B Movable terminal part of the present invention 51 Terminal body 52 Sleeve 53
Chuck piece 6 Support block 7 Spring 8 Lead 81 Lead terminal 82 Set screw 83
Hole

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[Procedure amendment]

[Submission date] July 15, 1997

[Procedure amendment 1]

[Document name to be amended] Drawing

[Correction target item name] All figures

[Correction method] Change

[Correction contents]

FIG.

FIG. 2

FIG. 3

FIG. 4

FIG. 5

FIG. 6

FIG. 7

Claims (3)

[Claims] In an impulse sealer for welding and / or fusing a plastic sheet by instantaneously energizing a heating wire to generate heat, a movable terminal portion for fixing the heating wire under tension is provided at one end. A cylindrical terminal main body having an external thread, a sleeve having an internal thread that engages with the external thread inside, and having a reduced inner diameter toward one end, a plurality of radially divided chuck pieces inside the sleeve, and An impulse sealer comprising an insulating support block for supporting a terminal body, wherein the support block is mounted at a predetermined position on a seal table so as to be able to move forward and backward. 2. A screw / nut mechanism or lever for advancing the support block against the force of the spring while providing a spring for urging the support block in a backward direction so as to always apply tension to the heating wire. The impulse sealer according to claim 1, further comprising a mechanism. 3. The impulse sealer according to claim 1, further comprising an air cylinder that moves the support block forward and backward and urges the support block backward so as to constantly apply tension to the heating wire.