EP1283798A1

EP1283798A1 - Device for tightening and sealing plastic packaging straps

Info

Publication number: EP1283798A1
Application number: EP01951457A
Authority: EP
Inventors: Detlef Scholl; Leo Zeimetz; Peter Nober
Original assignee: Cyklop GmbH
Current assignee: Cyklop GmbH
Priority date: 2000-05-26
Filing date: 2001-04-21
Publication date: 2003-02-19
Anticipated expiration: 2021-04-21
Also published as: DE10026198A1; DE50101149D1; BR0111177B1; EP1283798B1; AU7237601A; AU2001272376B2; WO2001089929A1; BR0111177A; US20030131570A1

Abstract

The invention relates to a device for tightening and sealing plastic packaging straps for packages. Said device comprises a housing (11), a strap channel (14) which extends in the longitudinal direction of the packaging strap (12), is open on one side and receives the strap ends (19, 20) that are to be mutually tightened, said channel being delimited on one side by a tightening plate (16) and on the other side by a tightening wheel (18), which is provided with a profiling, whereby the tightening wheel and the tightening plate can be adjusted in relation to one another. The aim of the invention is to exert a considerable tightening force on the ends of the bands, using a negligible adjusting force between the tightening wheel and the tightening plate, without damaging the strap by the rotation of the tightening wheel. To achieve this, the profiling of the tightening wheel consists of first transverse profile grooves (27) running approximately parallel to the axis of said wheel and second circumferential profile grooves (29) running parallel to the circumference, whereby the transverse profile grooves have a shallower groove depth (t) than the circumferential profile grooves. This arrangement forms tightening teeth (30) on the circumference of the tightening wheel, which penetrate the strap to the depth of the transverse profile grooves, even at a negligible adjusting force and enable the transmission of considerable tightening forces.

Description

Title: Device for tensioning and closing plastic strapping

The invention relates to a device for tensioning and closing plastic strapping for packages or the like., With a housing, a in the housing extending in the longitudinal direction of the strapping in the housing, open on one side and the mutually bracing strap ends of the strapping receiving the channel, the one side is delimited by a clamping plate and on the other side by a clamping wheel provided with a profiling, the clamping wheel and the clamping plate being adjustable relative to one another.

Devices of this type serve to clamp the strap ends of plastic straps placed around packages against each other and to connect them firmly by means of a closing device, so that the packages are then securely strapped. For this purpose, the strap ends of the plastic strapping are inserted into the strap channel that is open on one side so that they lie one above the other. Then the tensioning wheel and tensioning plate are adjusted relative to one another, so that one end of the strap lies firmly against the tensioning plate and the other end of the strap against the tensioning wheel, which is then rotated by hand or by motor and stretches the adjacent strap end relative to the strap end held firmly by the tensioning plate , When the desired tension is reached, the tape ends are firmly connected to one another by means of a friction welding device or other closure devices.

In order to achieve the tightest possible tensioning of the strapping, it is necessary to ensure the highest possible coefficient of friction between the plastic strap ends and the tensioning plate on the one hand and the tensioning wheel on the other. For this is in α 3 <l- ¹ o H ".) rt m σ 0: Λ U5 P- ω 0. 01 N ≥! 01« 01 Hl <! CΛ H- H- o P- Φ ι-J 0 φ H P- er ^• P ⁾ 0 φ φ 0 0 o lJ Ω Φ φ 0 φ 0 P- 0 φ rt 0 «QH φ φ 0 O 0 ι-J o φ φ pi Hi H 01 Hi 0 Φ y 0 Ω P- * lJ 0 o 0 lJ 0

Φ rt iQ ι-s Hi ιQ P ^J Hl 01 n 0 0 iQ Ω o 0 Ω 0 '• - {0 0 "Φ 01 y ⁱ -Q 01 0

Φ Φ 0 P- 0 P- φ 3 0 rt 0 ≥! - 0 'rt P- rt 0 0 rt 01 φ

P- α

P- 0 rt 0 P- * <! 0 P- ¹ pj: K Φ er: s: iQ 0 φ • et α Φ p * - 01 er Hl y

3 p H Hi H φ Hl P-> & a l-J 0 Φ y 0: Φ P- 0 rt P- 0 P- er 01 rt Φ P- Φ α

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P- P- Holy 3

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Φ s: CD 3 P- 0 0 s: i-i Hl H 0 H 0 Φ 0 0 0 i-J Φ 01 0

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Advantageously, the circumferential and / or transverse profile grooves thus form between them approximately pyramid-shaped, pointed clamping teeth, which can easily penetrate into the end of the band to be tensioned even with a low pressure force and can thus be gripped and tensioned in a practically positive manner. The transfer forces, which are large even with a low pressure force between the tensioning wheel and the tensioning plate, enable the strap ends to be firmly clamped against one another without the tensioning wheel turning on the corresponding strap end, so that no plastic material is removed from the strap end that was previously known Devices softened as a result of the frictional heat occurring when the tensioning wheel slipped on the end of the belt and settled into the profiling, from which it could only be removed with great difficulty after cooling and hardening.

The smaller depth of the transverse profile grooves compared to the circumferential profile grooves ensures that the clamping teeth cannot emerge from the bottom of the band end lying against the tensioning wheel and can engage in the other band end. For this purpose, the transverse profile grooves preferably have a groove depth that is smaller than the thickness of the thinnest strapping to be processed.

It is particularly advantageous if the tip angle of the clamping teeth enclosed by the groove walls of the profile grooves is less than 60 °, in particular between 35 and 45 °, because with such a small tip angle, complete penetration of the clamping teeth into the band is very small Contact pressure reached. The groove depth of the circumferential profile grooves is preferably 1.5 to 3 times the groove depth of the transverse profile grooves. The groove depth of the transverse profile grooves can be, for example, between 0.2 and 0.4 mm and the groove depth of the circumferential profile grooves between 0.6 and 1 mm.

A particularly advantageous embodiment is obtained if the tensioning plate also extends in the longitudinal direction of the band channel φ p. Hi Ό P- X 01 0 P- Λ W P. Hi er CΛ iQ CΛ IQ 03 CΛ CΛ φ P * P. OP * ^• es m

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Border profile grooves. 'When the tensioning wheel is rotated, the cleaning teeth peel impurities out of the circumferential profile grooves, and particularly thorough cleaning can be achieved in that the cleaning teeth extend with their tooth tips to the groove base of the circumferential profile grooves. Surprisingly, it has also been found that contaminants in the transverse profile grooves are also easily removed, since they generally adhere to the plastic or other particles that have become lodged in the circumferential profile grooves. In particular in the case of a trapezoidal configuration of the transverse profile grooves, the dirt particles which are fixed therein are easily removed again when the peripheral profile grooves are scraped out with the cleaning device.

The cleaning device can be set against the tensioning wheel under the action of a pressure spring and thus permanently clean it; however, it is also possible to operate the cleaning device only when required or at regular intervals. A particularly advantageous embodiment results when the cleaning block is approximately wedge-shaped and rests with a free wedge edge on the tensioning wheel, as a result of which the unhindered removal of the dirt particles removed from the grooves is reliably ensured. It is very particularly advantageous if the cleaning block consists of a soft metal, in particular a brass alloy, which leads to a self-sharpening effect when the cleaning block is pressed against the tensioning wheel. The cleaning teeth encircling the circumferential profile grooves are thereby optimally adapted to their shape and safely scrape out the profile grooves completely.

Further features and advantages of the invention result from the following description and the drawing, in which a preferred embodiment of the invention is explained in more detail with reference to an example. It shows: 1 shows a device according to the invention for tensioning and closing plastic strapping in a side view, the housing of the device being merely indicated;

FIG. 2 shows a section through the tensioning wheel and the tensioning plate of the device shown in FIG. 1 in the region of the strap channel when the strap is not inserted;

3 shows the object of FIG. 2 with the strapping inserted; and

4 shows a detail of the tensioning wheel in the area of the cleaning block interacting with it in an enlarged section IV according to FIG. 1.

The device 10 shown in Fig. 1, the housing 11 is indicated by dash-dotted lines for reasons of clarity, is used for tensioning and closing a plastic strapping 12 or the like about a package 13. should be placed.

For this purpose, the device 10 has a strap channel 14 which extends in the longitudinal direction of the strapping strap 12 in the housing and is open on one side, which is delimited on its underside 15 by a tensioning plate 16 and on its top 17 by a tensioning wheel 18 and in which the two strap ends 19, 20 of the strapping 12 are inserted from the open long side, as is known per se. For tensioning the strap ends 19, 20 against one another, the tensioning wheel 18 can be adjusted from above with an eccentric drive 21 against the fixed tensioning plate 16 in an unspecified manner, so that the two strap ends 19, 20 are clamped between the tensioning plate 16 and tensioning wheel 18, whereupon the Drive 22 for the tensioning wheel is actuated, which then pulls the upper band end 19 backwards into the device 10, to the right in the drawing, while the lower one Band end 20 is held in its position by the clamping plate 16. When the desired tension in the strapping band 12 is reached, the friction welding device 23 arranged in the longitudinal direction of the strapping band behind the tensioning wheel is actuated, which in a known manner rubs the upper band end 19 transversely to the longitudinal direction of the band at high speed over the lower band end and thus a firm weld connection of the two Band ends generated.

In order to achieve a high tension in the strapping band 12 even with low pressure forces between the tensioning wheel and tensioning plate and the strap ends between them, the tensioning wheel 18 is provided on its periphery 24 with a profile 25, the design of which can be seen in FIGS. 2 to 4. The profile 25 consists of first transverse profile grooves 27 running in the axial direction 26 of the tensioning wheel 18 and second circumferential profile grooves 29 running at right angles to this in the circumferential direction 28 and having a greater groove depth T than the transverse profile grooves. In the exemplary embodiment shown, the groove depth T of the circumferential profile grooves is approximately 0.7 mm, while the groove depth t of the transverse profile grooves is only 0.3 mm. 2 to 4 also show that the circumferential profile grooves have an approximately V-shaped cross-sectional shape and are close to each other, while the transverse profile grooves are trapezoidal in section. The circumferential and transverse profile grooves 27, 29 located next to or behind one another form between them approximately pyramid-shaped, pointed clamping teeth 30, the tip angle α of which is enclosed by the groove walls 31 of the profile grooves 27, 29 is approximately 40 °.

As can be clearly seen from FIG. 3, the clamping teeth 30 press slightly into the upper band end 19 down to the depth t of the transverse profile grooves 27 and thus ensure a practically positive connection between the profiling 25 even with a small pressing force of the tensioning wheel and the upper end of the band. The maximum depth of penetration, which is determined by the groove depth t of the transverse profile grooves, ensures that the clamping teeth 30 on the underside of the upper band end 19 do not emerge again. since the thickness D of the strapping is regularly more than 0.3 mm. Thus, it cannot happen that the clamping teeth 30 of the tensioning wheel are pressed through the upper band end into the lower band end, which would make it impossible to brace the two parts against one another.

As can further be seen from the drawings, the clamping plate 16 is provided with holding teeth 32 running in the longitudinal direction of the band channel 14, which, in the clamping position of the clamping plate 16 and the tensioning wheel 18 when the band is not inserted, is shown a little bit in the circumferential direction as shown in FIG. Border profile grooves 29. The holding teeth 32 ensure that the lower band end 20 is held firmly during the tensioning process in the band channel by pressing the holding teeth 32 into the lower band end from below, as do the clamping teeth 30 of the tensioning wheel 18 from the top in the upper band end 19. The special arrangement of the holding teeth and the clamping teeth relative to one another, in which the holding teeth protrude a bit into the circumferential profile grooves and correspondingly the clamping teeth into the holding grooves 33 formed between the holding teeth, if no strapping band is inserted between the clamping plate and the tensioning wheel, ensures a maximum possible tensile force exerted on the belt ends with low contact forces between the tensioning wheel and the tensioning plate. Since the clamping teeth or the holding teeth press firmly into the band ends from above or below even with slight pressure, there is no spinning of the tensioning wheel at the top of the upper band end or a pulling of the lower band end over the even with large clamping forces Clamping plate so that the strap ends are not damaged during tensioning and no or very little abrasion is generated during tensioning which could clog the profile grooves or the retaining grooves.

In order to keep the profile grooves 27, 29 free from this little abrasion or other dirt particles that have entered the device, the device 10 above the belt channel 14 is provided with a cleaning device 34 for the tensioning wheel 18, which substantial consists of an approximately wedge-shaped cleaning block 35, which is provided on its free, front wedge edge 36 with cleaning teeth 37 which engage in the circumferential profile grooves 29. The arrangement is such that the cleaning teeth 37 extend with their tooth tips 38 to the groove bottom 39 of the circumferential profile grooves.

The cleaning block 35 is pivotally mounted on an axis 40 and is pressed by a pressure spring 41 with its free wedge edge 36 against the tensioning wheel 18, the cleaning teeth with their tooth tips firmly pressing into the circumferential profile grooves 29 and, when the tensioning wheel rotates, in the Scrape out any accumulated contamination. It has been shown that the contaminants that have accumulated in the transverse profile grooves 27 are also carried away, since these grooves have only a shallower groove depth and, moreover, the trapezoidal shape of the profile grooves prevents impurities from caking firmly therein. The cleaning block consists of a softer metal than the tensioning wheel 18 or its clamping teeth, in the present exemplary embodiment made of brass, so that its cleaning teeth 37 are continuously reground when the tensioning wheel rotates and always fit exactly and without play into the circumferential profile grooves and thereby also these scrape it out completely.

By holding the clamping teeth 30 of the tensioning wheel 18 a little way into the holding grooves 33 when the strapping band is not inserted into the band channel, as shown in FIG. 2, the holding grooves are also freed of any impurities that accumulate therein when the tensioning wheel is not inserted Strapping is rotated. In order to prevent the clamping teeth and the holding teeth from colliding with one another or to prevent the tips of the clamping teeth 30 from touching the groove base of the retaining grooves 33 and thereby being damaged, the device 10 has a clamping wheel 18 in the clamping position relative to Lead clamping plate in the axial direction 26 of the tensioning wheel Locking mechanism "42, which essentially consists of a guide finger 43 rising from the clamping plate 16, which engages in a circumferential direction guide groove 44 in the clamping wheel 18. The arrangement is such that the guide finger 43 is in the clamping position of the clamping wheel and When the strapping band is not inserted in the band channel, its free end 45 rests from the guide groove bottom 46, the tips of the clamping teeth 30 still gripping between the holding teeth 32, but being held at a sufficiently large distance from the groove base of the retaining grooves 33. The guide groove 44 goes into their radially outer area to form a radius R in the circumferential surface of the tensioning wheel 18 and thus forms a centering guide 47 for the guide finger 43, which ensures that the floating tensioning wheel with its guide groove 44 always exactly engages with the guide finger when it is pressed against the clamping plate 43 arrives ,

Claims

PATENT CLAIMS

1. Device for tensioning and closing plastic strapping for packages or the like, with a housing, a one-sided open and the mutually bracing strap ends of the strapping receiving the channel extending on the one side, extending in the longitudinal direction of the strapping in the housing is delimited by a tensioning plate and on its other side by a tensioning wheel provided with a profile, the tensioning wheel and the tensioning plate being adjustable relative to one another, characterized in that the profile (25) consists of the first, approximately in the axial direction (26) of the tensioning wheel ( 18) extending transverse profile grooves (27) and second circumferential profile grooves (29) running in the circumferential direction (28), the transverse profile grooves (27) having a smaller groove depth (t) than the circumferential profile grooves (29) ,

2. Device according to claim 1, characterized in that the circumferential profile grooves (29) and / or the transverse profile grooves (27) have an approximately V-shaped or trapezoidal cross-sectional shape which tapers to the radially inner groove base (39).

3. Apparatus according to claim 1 or 2, characterized in that the circumferential profile grooves (29) have a V-shaped and the transverse profile grooves (27) have a trapezoidal cross-sectional shape tapering to the radially inner groove base (37).

4. Device according to one of claims 1 to 3, characterized in that the circumferential and / or transverse profile grooves (29th

| _ ^" I or 27) between them form approximately pyramid-shaped, pointed clamping teeth (30).

5. Device according to einöm of claims 1 to 4, characterized in that the transverse profile grooves (27) have a groove depth (t) which is smaller than the thickness (D) of the thinnest strapping to be processed (12).

6. Device according to one of claims 1 to 5, characterized in that of the groove walls (31) of the profile grooves (27, 29) included tip angle (α) of the clamping teeth (30) is less than 60 °.

7. The device according to claim 6, characterized in that the tip angle (α) is between 35 ° and 45 °.

8. Device according to one of claims 1 to 7, characterized in that the groove depth (T) of the circumferential profile grooves

(29) is 1.5 to 3 times the groove depth (t) of the transverse profile grooves (27).

9. Device according to one of claims 1 to 8, characterized in that the groove depth (t) of the transverse profile grooves (27) between 0.2 and 0.4 mm and the groove depth (T) of the circumferential profile grooves (29) between 0.6 and 1 mm.

10. Device according to one of claims 1 to 9, characterized in that the clamping plate (16) with in the longitudinal direction of the band channel (14) extending holding teeth (32) is provided, which in the clamping position of the clamping plate (16) and clamping wheel (18) If the tape is not inserted, insert it a little into the circumferential profile grooves (29).

11. The device according to one of claims 1 to 10, characterized by a locking mechanism (42) guiding the tensioning wheel (18) in the tensioning position relative to the tensioning plate (16) in the axial direction (26) of the tensioning wheel.

12. The device according to Anäpruch 11, characterized in that the locking mechanism (42) essentially from a from the clamping plate (16) projecting in a circumferential direction (28) circumferential guide groove (44) engaging in the tensioning wheel (18) guide finger (43 ) consists.

13. The apparatus according to claim 12, characterized in that the guide finger (43) in the tensioned position when the band is not inserted rests with its free end (45) on the guide groove bottom (46) of the guide groove (44).

14. Device according to one of claims 1 to 13, characterized in that the guide groove (44) in its radially outer region forms a centering guide (47) for the guide finder (43).

15. Device according to one of claims 1 to 14, characterized by a cleaning device (34) assigned to the tensioning wheel (18) for the profile grooves (27, 29).

16. The device according to one of claims 1 to 15, characterized in that the cleaning device (34) consists essentially of a cleaning block (35) with cleaning teeth (37) which surround the circumferential profile grooves (29).

17. The device according to one of claims 1 to 16, characterized in that the cleaning teeth (37) with their tooth tips (38) to the groove base (39) of the circumferential profile grooves (29).

18. Device according to one of claims 1 to 17, characterized in that the cleaning device (34) is set against the tensioning wheel (18) under the action of a pressure spring (41).

19. Device according to one of claims 1 to 18, characterized in that the cleaning block (35) is approximately wedge-shaped and with its free wedge edge (36) bears against the tensioning wheel (18).

20. Device according to one of claims 1 to '19, characterized in that the cleaning block (35) consists of a soft metal, in particular a brass alloy.