WO2009087216A2

WO2009087216A2 - Band drive for strapping machines

Info

Publication number: WO2009087216A2
Application number: PCT/EP2009/050213
Authority: WO
Inventors: Dieter Banholzer
Original assignee: Maschinenfabrik Gerd Mosca Ag
Priority date: 2008-01-11
Filing date: 2009-01-09
Publication date: 2009-07-16
Also published as: WO2009087216A3; DE102008004118A1; DE102008004118B4

Abstract

The invention relates to a strapping machine having a band-guiding channel and having a supply unit by means of which a strapping band is conveyed from a band store to the band-guiding channel, wherein the supply unit comprises the following: a pair of drive rollers which interact with one another and between which the band can be clamped and which form a supply and retraction drive; a pair of tensioning rollers which interact with one another and between which the band can be clamped and which form a tensioning drive. It is an object of the invention to further simplify the band drive. According to the invention, the strapping machine has only one motor 14 which directly drives one of the rollers, that is to say a drive roller 7 or a tensioning roller. If the drive roller 7 is directly driven by the motor 14, a movement transmission means 18 transmits the movement of the motor shaft of said motor 14 to a reduction gearing 20 which drives one of the tensioning rollers 9. If the tensioning roller is driven by the motor via a reduction gearing, a movement transmission means transmits the movement of the motor shaft of said motor to the drive roller.

Description

DESCRIPTION:

BELT DRIVE FOR STRIPPING MACHINES

Technical area

The invention relates to a strapping machine with a tape guide channel and a supply unit through which a strapping tape is fed from a tape supply to the tape guide channel, wherein the supply unit comprises: - a pair of cooperating drive rollers, between which the tape is clamped and the supply and Forming retraction drive,

- A pair of interacting tensioning rollers, between which the belt can be clamped and which form a tensioning drive.

State of the art

Strapping machines are well known in the art. For example, European patent EP 1 489 012 B1 discloses a strapping machine of the type mentioned in the introduction.

Such devices are used for strapping articles such as newspaper stacks, parcels or the like. The articles are usually transported on a conveyor in the tape guide frame, so that they protrude through the plane of the tape guide frame. A flat strapping tape is fed to the tape guide channel in the tape guide frame by means of the tape drive. Subsequently, the tape guide frame opens, whereby the formed belt loop is released in the radially inward direction and surrounds the object to be strapped. The strap loop is then tightened until tight around the strap Object is curious. In this state, the formed belt loop is separated from the tape supply, and the two ends of the belt loop are pressed against each other and connected together. The connection of the loop ends is usually done by welding.

Originally, the strapping machines had a drive motor coupled to the shaft of one of the drive rollers and to the shaft of one of the tension rollers. For transmission of motion, a drive belt or drive chain was usually used.

With the reduction of powerful drive motors one went over to arrange the drive motor and the clamping motor directly at the supply unit. On the shaft of the drive motor while one of the drive rollers was attached. The tensioning motor was designed as a geared motor with reduction gear, with the transmission output shaft carried one of the tension rollers. Such a strapping machine 1 according to the prior art is shown in Figures 1 and 2.

Fig. 1 shows a schematic side view of these known

Strapping machine 1. It is used for strapping objects 12 with a belt 11, which is withdrawn by a retracting device 4 from a supply roll 3. The withdrawn band 11 is introduced into a supply cassette 2, where a certain length of tape collects. By means of a feed unit 5 ', which has a feed drive with a pair of drive rollers 6', 7 'lying on opposite sides of the belt, the belt 11 is fed at high speed to a belt guide channel in a belt guide frame 13, so that the belt 11 forms a loop. The belt 1 1 is then withdrawn by the drive rollers 6 ', 7 ", so that the belt loop fits snugly against the object 12. Now, a clamping device also present in the feed unit 6 'is activated with a pair of tension rollers 8', 9 ', which clamps the belt loop around the object 12 with a predetermined high tension force. The tension rollers 8 ', 9' are driven at a lower speed but higher torque than the drive rollers 6 ', 7'. Thus, the tape feed and retraction by the drive rollers 6 ', 7' at high speed but low power and the clamping with high force but low belt speed.

After tensioning, the tensioned loop is cut from the supply of tape. The loop beginning is connected to the loop end by means of a closure unit 10. The closure assembly 10 is in practice e.g. from a welding device, which welds the two ends of the formed packing loop together. In general, plastic strapping are used, wherein the closure unit 10, the film-like plastic material from which the strapping band consists, melts and thereby the two end portions of the belt 11 welded together.

The object 12 is then transported out of the strapping machine 1, so that a next object can be strapped.

Fig. 2 shows the motors, which drive a drive roller T and a tension roller 9 ¹ . The driven drive roller T is seated directly on the motor shaft of the drive motor 14 '. The driven tension pulley 9 'is seated on the transmission output shaft of a tensioning motor 15' designed as a geared motor. The clamping motor 15 'has in the motor housing a reduction gear 20', which the - A -

Shaft speed of the transmission output shaft relative to the motor 15 'significantly reduced.

Disclosure of the invention The object of the invention is to further simplify the tape drive.

This object is achieved in a strapping machine of the type mentioned in two different ways.

According to a first aspect, when the strapping machine has a drive motor, on the motor shaft of which one of the drive rollers is arranged, it is proposed that a movement transfer means transmits the movement of the motor shaft of the drive motor to a reduction gear which drives one of the tension rollers.

In other words, the shaft of the drive motor carries one of the drive rollers and an element such as a gear or a pulley, with which the movement of the drive motor can be transmitted to the transmission input shaft of the reduction gear by a motion transmission means such as a chain or a belt or another gear , on the transmission output shaft, a tension roller is attached. In this way, a motor enough to drive both the supply and retraction drive and the tensioning drive. The drive rollers of the feed and return drive feed the tape at high speed to the tape guide channel in the tape guide frame so that the tape forms a loop, and tension the tape by subsequent high speed retraction so that the tape loop fits tightly against the article. The drive rollers thus have a high rotational speed with low torque. The tension rollers tension the belt loop with a predetermined high clamping force in order to and are driven at a lower speed but higher torque than the drive rollers

In contrast, if the strapping machine comprises a tensioning motor, which is provided as a geared motor with a reduction gear, wherein on the transmission output shaft, one of the tensioning rollers is arranged, it is proposed according to a second aspect of the invention that a motion transmitting means transmits the movement of the motor shaft of the tensioning motor to a shaft, on which one of the drive rollers is attached.

In this case, the only motor designed as a geared motor clamping motor is provided. The first end of the motor shaft drives the reduction gear, on whose transmission output shaft a clamping roller is attached. The other end of the motor shaft of the tensioning motor carries a member such as a gear or a pulley, with which by a motion transmission means such as a chain or a belt or another gear, the movement of the motor shaft of the tensioning motor is transmitted to the shaft of the drive roller. Also in this case, a single motor is sufficient to drive both the high and low torque drive and retract drive of the high speed, low torque drive rollers and the low speed, high torque tensioner drive of the tension rollers.

The driven drive roller and the driven tension pulley are permanently coupled together in both cases via the motion transmission means. In the drive and retraction phase, the force is transmitted to the strapping by pinching between the two drive rollers of the drive roller pair, the tape is not clamped here at a wide distance between the tension rollers. On the other hand, during clamping, the two clamping Roll pressed against each other, so that the tape is clamped between them, and between the drive rollers at the same time a wide gap is set.

As already mentioned, the motion-transmitting means may preferably be at least one of the following means:

- gear wheel;

- Chain,

- straps.

The rotation of the motor shaft can therefore be transmitted via a chain drive, belt drive or gear drive to the second shaft, which preferably runs parallel to the motor shaft. In principle, any motion transmission means can be used. The invention is not limited to a specific drive.

When a belt tensioned around two pulleys is used as the motion transmission means, in the first alternative in which only the drive motor is provided, a pulley may be arranged on the end of the motor shaft of the drive motor opposite the drive roller. A second pulley is mounted on the transmission input shaft.

On the other hand, in the case of the second tensioned motor alternative used as a motion transmission means, if a belt tensioned around two pulleys is used, a pulley may be disposed on the end of the motor shaft of the tensioning motor opposite to the transmission, with a second pulley disposed on the shaft of the drive pulley is. In both alternatives, a first tensioning roller is preferably displaceable with respect to the second tensioning roller, so that the width of the gap between the two tensioning rollers, through which the belt passes, is variable. The gap can be made wide when the feed and retract drive is active, allowing the tape to slip between the two idlers. To activate the tensioning drive, the two tensioning rollers are pressed against each other. The tape is thereby clamped between the tension rollers.

Also preferably, a drive roller is displaceable with respect to the second drive roller, so that the width of the gap between the two drive rollers, through which the belt passes, is variable. The gap between the drive rollers is set wide when the tension drive is active so that the belt passes between the two drive rollers with slippage. To activate the feed and retract drive, the two drive rollers are pressed against each other. The tape is clamped between the drive rollers.

In the known strapping machines of the applicant, the band is deflected by one of the drive rollers by an angle of about 75 °. The belt is fed in an obliquely upwardly running web, abuts the drive roller over approximately 75 ° and is finally guided in a substantially horizontal path to the belt guide channel. The wrapping of the drive roller through the strapping band is disadvantageous in a strapping machine according to the invention, in particular during tensioning of the band. The speed of the drive roller is much higher during clamping than the speed reduced by the reduction gear of the tensioner. In addition, tensioning roller and drive roller are coupled to one another via the motion transmission medium. A wrap of the drive roller over a large angular range due to the tensioned band with high force would result in a strong deceleration of the drive roller and the tensioning roller coupled thereto. For this reason, a guide element may be arranged in each case preferably on both sides of the narrowest gap between the two drive rollers, on the surface of which the band rests. In particular, the length of the contact region of the belt with the drive roller may be less than 25 mm. Beyond the contact area, the band is guided by the guide elements, which cover the peripheral surface of the drive roller.

In practice, the strapping machine may comprise a support element, on one side of which the motor, the reduction gear and the movement transmission means are arranged and on the other side of which the drive roller and the tension roller are arranged. By means of the support element substantially all elements of the supply unit are combined to form a mounting unit.

As in the prior art, each of the two tension rollers may comprise a gear, wherein the gears of the two tension rollers mesh with each other. In this way, the surfaces of the two tension rollers evenly transfer the clamping force to the strapping band. Even if the idler coupled to the motor should slip against the belt surface, the other idler is rotated by the motion coupling by means of the two sprockets.

Brief description of the drawings

Embodiments of the invention will be explained below with reference to the accompanying drawings. The drawings show in: 1 is a schematic side view of a Umreifungsmaschi- ne according to the prior art,

2 is an enlarged perspective view of the motors of the supply unit of the strapping machine of FIG. 1,

3 is a perspective view of the motors of the supply unit according to the invention,

4 is a perspective view of a tape guide frame with inventive supply unit, FIG. 5 is an enlarged perspective view of the supply unit of FIG. 4,

Fig. 6 is a representation corresponding to FIG. 3 of the motors of another embodiment of the supply unit according to the invention.

Embodiments of the invention

3 shows a perspective view of a part of the supply unit according to a first embodiment of the invention. In this case, only one drive motor 14 for the motor-driven drive roller 7 and the motor-driven tension roller 9 is provided. At the first end of the motor shaft 16 of the drive motor 14, a drive roller 7 is attached. At the second shaft end, a pulley 17 is fixed, which is wrapped by a toothed belt 18.

A second belt pulley 19, looped by the toothed belt 18, is seated on the transmission input shaft of a reduction gear 20. The reduction gear 20 may, for example, have a gear ratio of 1: 8. On the transmission output shaft 21, a tensioning wheel 9 is fixed. Consequently, the tensioning wheel 9 rotates one eighth of the speed of the transmission input shaft and thus with one eighth of the speed of the drive motor fourteenth

The complementary drive roller 6 and the complementary tension roller 8 can only be seen in FIG. In Fig. 3, they are omitted for the sake of clarity.

FIG. 5 shows that the two tensioning rollers 8, 9 carry intermeshing gears 22, 23. The gears 22,23 ensure that the tension rollers rotate 8.9 with opposite direction of rotation and identical speed.

During clamping, the tension roller 8 is pressed against the tension roller 9, so that the band is clamped between the two tension rollers 8.9.

During the supply and the withdrawal of the belt, a wide distance between the tension rollers is set 8.9, so that the tape is not clamped here. By contrast, in this second operating state, the drive roller 6 is pressed against the drive roller 7, so that a clamping force arises between these two rollers.

FIG. 3 also shows guide elements 24, 25, 26 on which the strapping band rests and which cover the circumference of the drive roller 9 and the tension roller 7 in the regions beyond the contact region 27 of the tension roller 9 and the contact region 28 of the drive roller 7. In particular, the upper guide member 26 is to be mentioned, which limits the contact region 28 of the drive roller 7 in its length. According to the prior art, the drive roller 7 was looped around an angle section of about 70 °. According to the invention, it is advantageous to reduce the contact area to a few millimeters ter (eg below 25 mm). Otherwise, the drive roller 7, which rotates at a much higher speed than the tension roller 9, would brake the drive motor 14 when the strapping band is tensioned around the drive roller 7 with high force. Characterized in that the contact region 28 of the drive roller is limited to a length of less than 25 mm, is substantially straight and runs parallel to the belt plane, the belt is not pulled with great force against the surface of the drive roller 7 during clamping and generates no significant braking force ,

FIG. 6 shows a representation corresponding to FIG. 3 of a second embodiment of a drive according to the invention. Here is designed as a single motor designed as a gear motor clamping motor 15 is provided on the transmission output shaft 21, the tension roller 9 is seated. On the opposite side of the housing of the tensioning motor 15, a pulley 19 is attached, which is coupled via a toothed belt 18 with a second pulley 17. The second pulley 17 is connected to the drive roller 7 via a rigid shaft 29. Since the motor shaft on which the belt pulley 19 is seated rotates at eight times the speed of the transmission output shaft of the tension motor 15 designed as a gear motor, the rotational speed of the drive pulley 7 is eight times as high as the speed of rotation of the tension pulley.

The shaft 29, at the end of which the drive roller 7 is fixed, is supported in a shaft housing 30 which is fixed to the support member 31 of the supply unit 5.

On one side of the support member 31, the rollers, namely drive and tension rollers are arranged. On the opposite side of the Supporting element 31 is the motor 14 (Fig. 3) and 15 (Fig. 6) with the reduction gear 20 and 20 '.

LIST OF REFERENCE NUMBERS

1 strapping machine

2 supply cassette

3 supply roll

4 retractor 5.5 'feed unit

6.6 'drive roller

7.7 'drive roller

8,8 'tension pulley

9.9 'tension pulley 10 locking unit

1 1 strapping band

12 subject

13 tape guide frame with tape guide channel 14, 14 'drive motor 15, 15' clamping motor

16 motor shaft

17 Pulley

18 timing belt, motion transmission

19 Pulley 20,20 'reduction gear

21 transmission output shaft

22 gear

23 gear

24 guide element 25 guide element

26 guide element Contact area of the tension roller Contact area of the drive roller Shaft Shaft housing Support element

Claims

CLAIMS:

A strapping machine (1) comprising a tape guide channel (13) and a feeding unit (5) through which a strapping tape (11) is fed from a tape supply (3) to the tape guide channel (13), the feeding unit (5) comprising :

- A pair of mutually cooperating drive rollers (6,7), between which the band (1 1) can be clamped and which form a supply and retraction drive, - a pair of interacting tension rollers (8,9), between which the band (1 1 ) can be clamped and form a tensioning drive,

- A drive motor (14), on the motor shaft (16) one (7) of the drive rollers (6,7) is arranged, characterized in that a motion transmission means (18) movement of the motor shaft (16) of the drive motor (14) to a Reduction gear (20) transmits, which drives at least one of the tension rollers (8.9).

2. strapping machine (1) with a tape guide channel (13) and a supply unit (5) through which a strapping tape (11) from a tape supply (3) to the tape guide channel (13) is passed, wherein the supply unit (5) comprises:

- A pair of cooperating drive rollers (6,7), between which the band (1 1) can be clamped and the one

Form feed and retraction drive,

a pair of cooperating tensioning rollers (8, 9), between which the band (11) can be clamped and which form a tensioning drive, - A tensioning motor (15) which is provided as a geared motor with a reduction gear (20 '), wherein on the transmission output shaft one (9) of the tensioning rollers (8,9) is arranged, characterized in that a movement transmitting means (18), the movement of Motor shaft of the tensioning motor (15) to a shaft (29) transmits, on which one of the drive rollers (7) is attached.

3. strapping machine (1) according to claim 1 or 2, characterized in that the motion transmission means is at least one of the following means:

- gear wheel;

- Chain,

- Belt (18).

4. strapping machine (1) according to claims 1 and 3, characterized in that as movement transmission means to a two pulleys (17,19) tensioned belt (18) is used and that on the drive roller (7) opposite end of the motor shaft (16 ) of the drive motor (14) a pulley (17) is arranged, wherein a second pulley (19) is arranged on the transmission input shaft.

5. strapping machine (1) according to claims 2 and 3, characterized in that as movement transmission means around a two pulleys (17,19) tensioned belt (18) is used and that on the said transmission (20 ') opposite end of the motor shaft Tensioning motor (15) a pulley (19) is arranged, wherein a second pulley (17) on the shaft (29) of the drive roller (7) is arranged.

6. strapping machine (1) according to one of the preceding claims, characterized in that a tension roller (8) with respect to the second tension roller (9) is displaceable, so that the width of the gap between the two tension rollers (8,9), by the tape runs through, is changeable.

7. strapping machine (1) according to one of the preceding claims, characterized in that a drive roller (6) with respect to the second drive roller (7) is displaceable, so that the width of the gap between the two drive rollers (6,7), through the tape runs through, is changeable.

8. strapping machine (1) according to claim 7, characterized in that on both sides of the narrowest gap between the two drive rollers (6,7) each have a guide element (25,26) is arranged, on the surface of which the band rests.

9. strapping machine (1) according to claim 8, characterized in that the length of the contact region (28) of the belt with the drive roller (7) is less than 25 mm.

10. strapping machine (1) according to one of the preceding claims, characterized in that it comprises a support member (31) on one side of the motor (14 or 15), the reduction gear (20 or 20 ') and the motion transmission means (18) are arranged and on the other side of the drive roller (6,7) and the tension roller (8,9) are arranged.

1 1. Strapping machine (1) according to one of the preceding claims, characterized in that each of the two tension rollers (8,9) a gear (22,23) and that the gears (22,23) of the two tension rollers (8,9) mesh with each other.

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