JPS5924387Y2 - Glue applicator for bookbinding - Google Patents

Description

[Detailed explanation of the idea] This invention relates to a glue applicator for bookbinding.

It is well known that during bookbinding, glue is applied to one end of the paper, and the glue is used to bind the paper into a booklet and to attach a cover.

It is already well known that in order to apply glue, a drum whose lower half is immersed in glue liquid is rotated, and the back of the clamped paper is moved so as to rub against the upper circumference of the drum. There is.

However, when applying glue in this way, if the glue is applied to the entire back side of the paper, then when the cover is strongly pressed to the back side in order to attach the cover to this back side, the glue will cover the leading edge and back of the paper. It may protrude and adhere to the edges, making the appearance of the booklet extremely unsightly.

Also, if the cover is shorter than the back of the paper, when pasting the cover, the back edge of the paper that protrudes from the cover will come into contact with the surface of the stand that supports the cover, and the glue applied there will be damaged. The adhesive may adhere to the stand, staining the stand, and when the cover is next placed on the stand, the cover may come into contact with the glue that has adhered to the stand, causing the cover to adhere to the stand.

In order to avoid these problems, a wiper is installed on the drum for glue application, and the wiper wipes off the glue on the drum before the leading edge of the paper reaches the drum. Then, the wiper stops scraping off the glue, and before the trailing edge of the paper reaches the drum, the wiper scrapes off the glue again, and after the trailing edge has passed the drum, the wiper stops scraping off the glue. Just do it like this.

However, it is conceivable to control such a wiper using a cam, but since the size of the paper is not always the same, the cam must be adjusted according to the length of the back surface, which is inconvenient. There is.

The purpose of this invention is to set the length of the non-applied portion at both ends of the paper to a preset length, regardless of the length of the back surface of the paper, when applying glue to the back surface of the paper.

Examples of this invention will be described below with reference to the drawings.

1 is a sheet of paper whose back sides are aligned on a table 2.

Then, it is clamped by a clamper (not shown) and transported in the direction of arrow P.

A glue applicator 3 is installed along this transfer path.

It mainly consists of a container 4 containing glue (for example, hot melt adhesive), a rotatable drum 5 whose lower half is immersed in the glue, and a wiper 6 that can freely come into contact with the circumferential side of the drum 5. It is composed of

The drum 5 is rotated by a drive source (not shown) (for example, rotated in a direction opposite to the conveying direction of the paper 1), and at this time,
The glue comes to adhere to the circumferential side of the upper half of the drum 5 above the glue.

Then, the back side of the transferred paper 1 comes into contact with the uppermost peripheral side of the drum 5, and at this time, the drum 5
The glue attached to the screen will now be applied to the back side.

A shaft 7 is fixed to the base end side of the wiper 6, and this shaft 7
is rotatably supported by the side wall of the container 4.

One end of the shaft 7 led out of the container 4 is connected to an arm 8.
It is fixed.

A spring 9 is attached to one end of the arm 8, and the elastic force of the spring 9 constantly rotates the arm 8 in a clockwise direction.

This rotation causes the shaft 7 to rotate in the same direction, so that
The wiper 6 is held at a position away from the circumferential side of the drum 5.

A plunger 11 of a solenoid 10 is connected to the other end of the arm 8.

When the solenoid 10 operates, the plunger 11 is attracted and lowered, so that the arm 8 rotates counterclockwise against the elasticity of the spring 9.

As a result, the shaft 7 also rotates in the same direction, and the wiper 6 comes into sliding contact with the circumferential surface of the drum 5, thereby removing the glue adhering to the circumferential surface.

A paper detector is installed along the transport path of the paper 1 and in front of the glue applicator 3.

The illustrated example consists of a light emitter 12 (for example, a light emitting diode) and a light receiver (for example, a phototransistor) 13, which are arranged on both sides of the transferred paper 1.

Normally, the light receiver 13 receives the light from the light emitter 12 and outputs an output signal.

This output signal is amplified by an amplifier 14 to become a signal a.

The signal a is waveform-shaped by an inverting shaping circuit 15 and a shaping circuit 16, and then the signal a is converted into a signal.

It becomes e.

Signals S and e are applied to delay circuits 17 and 18, respectively, and are delayed by predetermined delay times D1 and D1 from the rise of signals S and e, respectively. After D2, the sumo wrestlers will signal.

It outputs signals c and f that fall simultaneously with the fall of e.

The signals c and f are applied to monostable circuits 19.20, which are analogous to pulse signal generation circuits, and a pulse signal d5g of a constant width is output from each monostable circuit 19.20.

Both pulse signals d7g are applied as signals to the solenoid 10, and operate only during the period when the signals are applied.

In the above configuration, when the leading edge of the paper 1 reaches between the light emitter 12 and the light receiver 13, the signal a falls.

Similarly, when the rear end finishes passing, the signal a rises.

Upon receiving the signal a, the inversion shaping circuit 15 outputs a signal S which is an inversion of the signal a.

A delay circuit 17 receiving the signal S outputs a signal C which rises with a delay of time D1 after the rise of the signal S.

Here, this time D1 is set to be shorter than the time required for the leading edge of the paper 1 to reach above the drum 5 after reaching between the light emitter 12 and the light receiver 13.

This can be easily set if the transport speed of the paper 1 and the distance from the paper detection position by the light emitter 12 and the light receiver 13 to the drum 5 are determined.

When the delay time D1 has elapsed, a pulse signal d is output from the monostable circuit 19, and a signal based on this pulse signal d operates the solenoid 10 for the duration of this signal, causing the wiper 6 to stick to the drum 5. Scrape away the glue.

During the time when the pulse signal d is output, the leading edge of the paper 1 reaches above the drum 5 when a time t1 has elapsed since the pulse signal d rose.

Then, since the pulse signal d falls when time t2 has elapsed after reaching this point, the operation of the solenoid 10 ends at this point, and the scraping of the glue on the drum 5 is completed, so that no glue adheres to the drum 5 at this time. , the glue is paper 1
It will be possible to completely coat the back of the.

This prevents the adhesive from being applied to the back surface of the paper 1 by a length of 1□ from the leading edge.

As can be understood from the above explanation, the glue is not applied during the period when the paper 1 is transported for the time t2 while the leading edge of the paper 1 reaches the upper part of the drum 5, so that the length 1
1 is expressed as Vt2, assuming that the transport speed of paper 1 is .

Therefore, the length 11 will always be the same if the transfer speed V', the width of the pulse signal d, and the delay time D1 are constant.

When the rear end of the paper 1 passes between the light emitter 12 and the light receiver 13, the signal a rises, and at this time the signal e also rises.

A delay circuit 18 receiving this signal e outputs a signal f which rises with a delay of a predetermined delay time D2.

This delay time D2 is set to be shorter than the time required for the rear end of the paper 1 to reach above the drum 5 after passing between the light emitter 12 and the light receiver 13.

When the delay time D2 has elapsed, a pulse signal g is output from the monostable circuit 20, and the solenoid 10 is activated by the signal based on this pulse signal g for the duration of this signal, causing the wiper 6 to adhere to the drum 5. Scrape away the glue.

At the time when the pulse signal g rises, the trailing edge of the paper 1 has not yet reached the top of the drum 5, and does not reach the top of the drum 5 until time t3 has elapsed thereafter.

Then, when the time t4 further elapses, the pulse signal g falls, and the wiper 6 finishes scraping off the glue.

As can be understood from these explanations, the paper 1 starts from time t3 before the time when the trailing edge of the paper 1 reaches the upper part of the drum 5.
The trailing edge of the paper 1 passes above the drum 5 until the pulse signal g falls after the application of glue is stopped, and then the pulse signal g falls.

As described above, the application of glue is stopped before the trailing edge of the paper 1 reaches above the drum 5, and this stop continues until the trailing edge of the paper 1 finishes passing above the drum 5.

The length 1° of the trailing edge of the paper 1 where no glue is applied will always be the same length if the delay time D2 of the delay circuit 18 is constant.

In FIG. 4, T indicates the time period during which the glue is applied.

Furthermore, as understood from the above explanation, each length is 1□, 1□
is the same regardless of the length of the paper 1 (the length along the transport direction), but this length can be easily changed by adjusting the delay circuits of each delay circuit 17 and 18. It becomes possible.

Further, the cover may be attached in advance after the paper 1 has passed above the glue applicator 3, or the cover may be attached in advance when the paper 1 has passed above the glue applicator 3.
After leaving the sheet 1 and heading for the glue applicator 3, the cover is placed on this stand 2, and when the paper 1 has finished passing through the glue applicator 3, it is sent backwards and transferred to the top of the glue 2 again. You may also attach a cover here.

In this case, it is necessary to lower the glue applicator 3 (or only the drum 5) when the paper is fed backwards so that glue is not applied to the paper that is being fed backwards.

Similarly, the table 2 is lowered slightly so that it does not come into contact with the paper that is being fed backwards, and when the paper reaches the top of the table 2,
It is necessary to raise the platform 2.

As detailed above, according to this invention, when applying glue while leaving the front and rear edges on the back side of the paper, the length of this non-applied part can be kept constant regardless of the length of the paper. This has the advantage that there is no need to adjust the cam or other parts every time the length of the paper differs, unlike in the past.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an embodiment of this invention, FIG. 2 is a front view thereof, FIG. 3 is a block diagram for control, and FIG. 4 is a time chart for explaining the operation. 1...Paper, 3...Glue applicator, 5.
...Drum, 6...Wiper, 12...
...Emitter, 13...Receiver, 17, 18
...Delay circuit, 19.20...Pulse signal generation circuit.

Claims (1)

[Scope of utility model registration request] A glue applicator is installed in the transport path of the paper being transported,
A bookbinding device comprising: a drum for applying the glue, the circumferential side of which slides on the back surface of the paper to apply the glue; and a wiper that slides against the circumferential side of the drum to wipe off the glue. In the glue applicator, there is provided a paper detector that detects the paper being transferred in front of the glue applicator, and a predetermined period of time that has elapsed since the leading edge of the paper was detected by the paper detector. When the pulse signal is output, a pulse signal is output, and the pulse signal generation circuit is set so that the leading edge of the paper reaches above the drum during the period when this pulse signal is output, and the paper detector detects the trailing edge of the paper. A pulse signal is output when a certain predetermined period of time has elapsed since the edge was detected, and the trailing edge of the paper is set to reach above the drum during the period when this pulse signal is output. A bookbinding glue applicator comprising: a pulse signal generating circuit; and a wiper driven to wipe away glue by pulse signals from both of the pulse signal generating circuits.