DE9006374U1 - Reefing and/or stretching device for tubular stretch wrapping film - Google Patents

Description

Soefameit & Boehmcrt, Bremen / Munich

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8OuO Munich 2

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PATENT ATTORNEY DR.-ING. KARL BOEHMERT (1933-1973) PATENT ATTORNEY DIPL.-ING. ALBERT BOEHMERT", BREMEN ATTORNEY WILHELM J. H. STAHLBERG, BREMEN PATENT ATTORNEY DR.-ING. WALTER HOORMANN*. BREMEN PATENT ATTORNEY DIPl-PHYS. DR. HEINZ GODDAR*. MUNICH PATENT ATTORNEY DR.-ING. ROLAND LIESEGANG·. MUNICH ATTORNEYS WOLF-DIETER KUNTZE, BREiiEN" PATENT ATTORNEY DIPU-HuV^ «OSEÜTMÜNZHUBER·, MUNICH P/iTENTANWAI-T DIPL-ING. EDMUND P. EITNER*. MUNICH ATTORNEY DR. LUDWIG KOUKHIi, BREMEN PATENT ATTORNEY DR. RER. NAT- ANDREAS WINKLER. BREMEN

* EUROPEAN PATENT ATTORNEY

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B2402

Burning

June 6, 1990

Bernhard Beumer Maschinenfabrik KG, Oelder Strasse 40, 4720 Beckum

Reefing and/or stretching device for tubular stretch wrapping film

The invention relates to a device for reefing and/or stretching tubular or hood-shaped stretch film when wrapping piece goods, in particular cuboid or cube-shaped stacked piece goods, such as, for example, and in particular, multi-layered, palletized stacks of piece goods, using stretch film, with a (reefing) frame consisting of several bow-shaped frame sections arranged essentially in one plane, over which the supplied, spread-out (tubular) stretch film is to be pulled before wrapping the piece goods, the clear frame contour being larger

Office Bremen / Bremen Office: Office Munich/Munich Office (mirPiicnurmiuo Hollerallee 32, D-2800 Bremen 1 WidenmayerslraRc 4, D-8000 Munich 22 P.O.Box 1071 27 P.O.Box / P.C) Iiox2201 37 Telephone: (0421) ·34 90 71 Telephone: (089)* 22 33 11

_&Kgr;1&Ogr; Telex: 244 958bopatd Telex: 524 282 forbod

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Cables: Diagram Bremen Cables: Telepatent Munich Deutsche Bank, Bremen Bremer Bank, Bremen Hvpobank, Munich l'ScliA Hamburg

(BLZ29070050) I Il 2002 (BLZ290.(<()() ICf) ¹ M)(J&Iacgr;'44 9()0 ''·ißIÄ>70020001)6400 194333 (BLZ200 100201 12M)H3 202

BOEHMERT

is (or is to be made larger) than the outer contour of the item to be wrapped, the frame sections have a substantially continuous, preferably rounded or curved shape at least in the area of their outer side that comes into contact with the stretch film, and the frame sections are each held by means of a frame section support.

A device for wrapping piece goods with a stretch film hood is known from DE-GM 88 08 508. The tubular stretch film is pulled section by section from a film supply by a pulling device and separated from the film supply by means of a cutting device, whereby the pulling device is provided with a spreading device for pulling apart and later spreading the film section that later forms a hood, furthermore a reefing device arranged downstream of the spreading device for reefing the film section over a vertical distance that is smaller than the length of the film section, furthermore a welding device arranged between the spreading device and the reefing device for forming a seam, and finally a stretching device by means of which the film section is to be stretched, and a lifting device by means of which the hood formed is finally to be pulled over the piece goods to be wrapped located underneath.

In this known device, the reefing and stretching device has a so-called reefing frame, which consists of four bow-shaped frame sections ("reefing brackets") arranged in a horizontal plane, which in plan view each have the shape of an equal-sided L, with the apex area being rounded. The tubular or hood-shaped stretch film is guided over these bow-shaped frame sections before the item is wrapped.

BOEHMEW&BOEHMERT

-Z-

and applied to frame section supports ("reefing beams") in a reefed state (i.e. folded) before stretching takes place by moving the bow-shaped frame sections apart and then pulling the stretched film cover over the piece goods to be wrapped, whereby it should fit tightly against the piece goods in order to create a transport security and a weatherproof loading unit.

If the coefficient of friction between the film material and the surface of the bow-shaped frame sections that comes into contact with it is relatively high, the film may only be pulled over the bow-shaped frame sections at a relatively low speed in order to avoid overstretching. If, however, the coefficient of friction is very low, a relatively high lowering speed must be used at least if, in addition to the horizontal stretch already mentioned above, a considerable vertical stretch of the film material is also to be achieved.

Especially for the latter, the known device or its gathering and/or stretching device provides a certain undercut between the bow-shaped frame sections and the supports that hold them. However, it has been shown that this undercut must not be too large in order to ensure that the film slides off the bow-shaped frame sections properly.

Furthermore, the extensive (further) development work has shown that the design of the bow-shaped frame sections and in particular their supports are of considerable importance for proper operation.

BOEHMERT &'BOEKMERT

to.

The present invention is based on the object of improving the known reefing and/or stretching devices in particular so that not only a perfect stretching and reefing of the tubular film material, but also in particular an optimal, perfect sliding off of the device (onto the piece goods to be wrapped) is possible.

The solution to this problem is that the frame section supports are each designed with a flat (i.e. no longer essentially linear) outer side, which extends from the (lower) side of the relevant frame section facing away from the film feed direction in the film feed direction (downwards), and which - essentially following the shape of the relevant frame section in a projection plane running transversely to the film feed direction - extends at least at the upper end section essentially over the length of the relevant frame section.

In a preferred embodiment, the frame section supports can be designed in the form of plates (and of course curved at least in the "corner area") and can be made of sheet metal, for example, but they can also be made of appropriately designed plastic blocks or the like. Another variant that makes use of the inventive concept is, for example, that the frame section supports each consist of essentially parallel bars or the like, the outer envelope of which forms a flat outer side, so that the effect sought according to the invention can be at least essentially achieved.

According to a highly preferred embodiment, the outer side of the frame section facing the foil material

BOF.HMERT&'BOEMVTERT " ' "

Supports should be tapered from the relevant frame section, whereby the free edge of a frame section support remote from the frame section

is (still) outside the contour of the piece goods to be wrapped or is to be brought into such a position.

The frame sections preferably protrude laterally beyond their support so that the latter is undercut, so to speak, wherein the protrusion of the outer contour of the frame sections above their associated support preferably decreases towards the end sections of the relevant frame section.

For a cube- or cuboid-shaped stack of goods,

% the frame sections are each arranged in a corner area,

wherein they can each preferably be formed in the shape of a circular arc in their central area over an angle of approximately 90° in the top view and, in a further embodiment, a section can be connected to the essentially circular arc-shaped section at both ends, which has a small curvature or is angled inwards.

The frame section supports are preferably designed (seen in plan view) in their two end regions to run essentially tangentially to the curvature of the films stretched between them, so that an optimal transition is ensured.

In a further embodiment of the present invention, the middle area of the frame section supports can be recessed, whereby the edge sections facing each other on the recessed part of a frame section support are then preferably rounded or curved inwards in order to ensure unhindered inflow and outflow.

BOEHMERT &'

At least one reefing roller can be assigned to one or each frame section, whereby the reefing rollers can be moved towards or away from the reefing section assigned to them. It has been found that the reefing rollers should preferably be arranged in the upper area of a frame section support in order not to hinder the actual reefing process in any way.

For the horizontal stretching process, the frame sections must be moved apart so that their mutual distance increases.

Furthermore, it is not obligatory that the frame sections are essentially only present in the corner areas. Rather, at least two (or possibly all) adjacent frame sections can be connected to one another, and in such a design they should preferably be telescopic, in order to still be able to move apart in a practical way.

Preferred embodiments of the present invention are described in the subclaims.

The invention is explained further below using an embodiment with reference to a drawing. It shows:

Fig. 1 is a somewhat simplified spatial representation of a stack of items to be wrapped with a stretch film hood;

Fig. 2 is a representation according to Fig. 1 after the

Welding the film tube and

BOEHMERT ·& BOEHMERT ·

separating the foil cover;

Fig. 3 is a representation according to Figs. 1 and 2, in which the film hood is already stretched transversely ;

Fig. 4 is a view according to Figs. 1 to 3 during the pulling process;

Fig. 5 a partial plan view of the reefing and

Spreading device in an enlarged view compared to Figs. 1 to 4;

Fig. 6 is a plan view (enlarged compared to Fig. 5) of a frame section and its support, seen in the direction of arrows VI in Fig. 5;

Fig. 7 is a plan view of a bow-shaped frame section corresponding to Fig. 5 but reduced in size compared to Fig. 5;

Fig. 8 is a side view of the frame section support of the bow-shaped frame section according to Fig. 7, seen in the direction of arrow VIII in Fig. 7; and

Fig. 9 a cross-section through a bow-shaped frame section and the upper part of its support with gathered foil.

Fig. 1 to 4 show a multi-layered, cuboid-shaped stack of items 1 stacked using a Giner palletizing device, which is to be wrapped with a film hood 2 made of stretch film (stretch film) consisting of

BOEHMERT &BOEHMERT· ··' .·*"·.*

tubular stretch film material 3, which is fed from a tubular film supply (not shown).

Fig. 1 shows the state in which the lower section of the supplied tubular silicon film material 3 has already been removed from the reefing and stretching device (not described in detail below).

Fig. 2 shows the state in which the supplied hose

shaped stretch film ms tsrial 3 of the formed film- _f;

hood ? is already separated, which for this purpose by means of 1

a welding device 4 at its upper end a transverse t

seam 5. In addition, Fig. 2 shows that %

the foil hood 2 is already essentially on the reefing and f

Stretch device has been reefed. >

From Fig. 3 it can be seen how the hood 2 gathered onto the reefing and stretching device has been stretched horizontally by moving apart its frame sections ( described in more detail below) in the direction of the arrows 6 in order to be able to be pulled over the stack of items 1; and Fig. 4 shows an intermediate step in the wrapping of the stack of items 1, in which the upper end section of the stack of items 1 is already wrapped by the film material of the film hood 2, while the lower end section of the stack of items is still free, but will nevertheless be wrapped when the reefing and stretching device is lowered further in the direction of the arrows 7.

The reefing and stretching device already mentioned has a reefing frame, which essentially consists of four bow-shaped frame sections 8 arranged in a (horizontal) plane (of which only

BOEHMERT & BOEHMERT

two frame sections 8 are shown), and each of which is arranged in a corner area at a distance from the item to be wrapped, which is indicated in Fig. 5 with a knitted two-dot line.

The frame sections 8 are each made of polyurethane material and are each circular-curved in plan view in their middle area over an angle α of 90°. The middle circular-curved section is adjoined at both ends by a section 10 which has a finer curvature or is angled inwards, so that the ends 11 and 12 of the frame section 8 and their end sections 10 are free in the film material of the hood 2 and - for the latter an optimal transition into the "free section" to the adjacent frame section 8 is provided.

As can be seen from the top view according to Fig. 5 and also from Figs. 6 to 9, the frame sections 8 each protrude laterally beyond their frame section support 12, so that the latter is, as it were, undercut. This overhang a decreases at/towards the end sections 10, as can be seen from the lower part of Fig. 5.

The frame section supports 12 are each designed with a flat outer side 13 and extend from the underside 15 (see Fig. 6) of the relevant frame section 8 facing away from the film feed direction 14 (see Fig. 1) downwards in the film feed direction 14, namely in a (horizontal) projection plane running transversely to the film feed direction 14, essentially following the shape of the relevant frame section 8 at least in the area from the end sections to a middle area. The frame section supports 12, referred to above and below as "supports", are in the embodiment shown.

BOEHMERT & BOEHWERT

For example, they are plate-shaped and made of sheet metal. In one variant, however, they could also consist of a large number of parallel bars or the like, the outer shell of which forms a flat outer side in the sense of the present invention.

As can be seen in particular from Fig. 6, in the exemplary embodiment shown, the supports 12 made of sheet metal each extend conically tapered downwards from the associated frame section 8, the middle region 12' of the supports 12 each being recessed and the edge sections 16, 16 facing each other being rounded off at the recessed part 12'.

The surfaces of the frame sections 8 and the supports 12 that engage with the film 2 are polished to enable good sliding.

As can be seen in particular from Fig. 5, the supports 12 (seen in plan view) each run at their two end regions 17 essentially tangentially to the curvature of the film 2 to be stretched between them, so that an excellent transition is produced.

Each frame section 8 is assigned a reefing roller (not shown in detail in the drawing) which can be swung towards the frame section 8 assigned to it (and can therefore also be swung away again). The reefing rollers are arranged in the upper area of a support 12 in order not to hinder the reefing process in any way.

The frame sections 8 are to be moved apart according to Fi ₅ /. 3 while increasing their mutual distance in order to form the film hood 2 in the form already described.

BOEHMEFFr& BÖEHMERT' '

stretcher!

In the process as described above with reference to Figs. 1 to 4, the lower end section of the tubular stretch film material 3 is first pulled over the four bow-shaped frame sections θ and gripped by the gathering rollers (not shown in detail in the drawing), which gather the film material 3 over the bow-shaped frame sections 8 onto the frame section supports 12 in the manner shown in Fig. 2. Due to the design of the frame sections 8, the (elastic) film is clearly not overstretched - especially at the transition sections. Rather, due to the highly expedient design of the bow-shaped frame sections 8 according to the invention (in the top view see Fig. 5), an extremely smooth transition to the "free areas" takes place.

Likewise, a highly expedient transition is made from the bow-shaped frame sections 8 to the frame section supports 12, as can be seen in particular from Fig. 9, where the reefed foil is indicated and designated with 3 ^:.

The same applies to horizontal stretching according to Fig. 3 and, not least, when pulling the stretch film hood over as shown in Fig. 4. Until it is gently and tightly attached to the stack of items 1, the film hood 2 can be held with the reefing rollers if necessary in order to reliably prevent vertical springing back.

Overall, the reefing and spreading device according to the invention represents a design that, at relatively high working speeds and corresponding penetration capacity, enables optimal wrapping of piece goods with tubular shape!

BOEHMERT & BOTHMERT

or hood-shaped stretch film and leaves nothing to be desired in either technical or economic terms.

BOEHMERT & BdEVlMEKT

Battery: B24O2

REFERENCE 3 NUMBER ^
(LIST OF RSFaREKGE NUMERALS)

1 piece goods stack 1 2 foil hood 3 tubular stretch film material 3 ' - qereffte slide 4 Welding device 4 5 Cross seam (of 2) 5 6 arrows 6 7 arrows 7 8 bow-shaped frame sections 8th 9 Contour (of 1) 9 10 end sections (of 8) 10 11 ends (of 8 or 10) 11 12 (Frame section) support 12' - middle Range (of 12) 13 Outside (of 12) 13 14 Film feed direction 14 \y uui.eisej.Le vvuii o; 16 marginal sections 16 17 end areas (of 12) 17 18 18 19 19 20 20 21 21 22 22 23 23 24 24 25 25 PP. 26 27 27 28 28 29 29 30 30

Claims (20)

Bernhard Beumer Maschinenfabrik KG, Oelder Straßp 40, 4720 Beckum Reefing and/or stretching device for tubular stretch wrapping film Claims 1. Device for reefing and/or stretching tubular or hood-shaped stretch film when wrapping piece goods, in particular cuboid or cube-shaped stacked piece goods, such as, for example, and in particular multi-layered, palletized piece goods stacks using stretch film, with a (reefing) frame consisting of several bow-shaped frame sections arranged essentially in one plane, over which 518 Office Bremen / Bremen Office: Hollerallee 32, D-2800 Bremen 1 PO Box / &Rgr;.&Ogr;&Lgr;&ogr;&khgr; 10 7127 Telephone: (0421)*349071 Telex: 244 958 bopatd Fax: (04 21) 34 69 68 CClTT &Pgr;+III Cables: Diagram Bremen Munich Office (only Widenmayerstrasse 4, D-8000 Munich 22 P.O. Box 22 0137 Telephone: (089)* 223311 Telex: 524 282 forbod Fax: (089) 2215 69 CCITTII+III Cables: Telepatent Munich :utsche Bank. Bremen Bremer Bank, Bremen Hypobank, Munich PSchA Hamburg LZ29070050) 1112002 (BLZ29080910) J0pi44£&) "\· '(Bb^70020001)64001^TT" (BLZ20010020) 126083-202 BOEHMEFFr& BOEHMERT* the guided, spread stretch film is to be pulled before wrapping the item, the clear frame contour being/being made larger than the outer contour of the item to be wrapped, the frame sections having a substantially continuous, preferably rounded or curved shape at least in the area of their outer side engaging with the stretch film, and the frame sections are each held by means of a frame section support, characterized in that the frame section supports (12) are each designed with a flat outer side which extends from the side (15) of the relevant frame section (8) facing away from the film feed direction (14) in the film feed direction (14) and extends in a projection plane running transversely to the shape of the relevant frame section (8), essentially following the shape of the relevant frame section (8), at least at the upper end section, essentially along the relevant frame section (8). 2. Device according to claim 1, characterized in that the frame section supports (12) are plate-shaped. 3. Device according to claim 2, characterized in that the frame section supports (12) consist of sheet metal or the like. 4. Device according to claim 1, characterized in that the frame section supports (12) consist of essentially parallel rods or the like, the outer envelope of which forms a flat outer side. 5. Device according to one or more of the preceding claims, characterized in that the outer side of the frame section supports (12) facing the film material is in each case conically tapered from the relevant frame section (8). BOEHMERTT& BOEHMERT * '" &bull; · ■ ····■ &phgr;« « _t &bull; · &igr;#&diams; · ■ 6. Device according to one or more of the preceding claims, characterized in that the frame sections (8) each protrude laterally beyond its support (12). 7. Device according to claim 6, characterized in that the upper part (a) of the outer contour of the frame sections (P*) decreases over the associated frame section support (12) to the lower sections (10) of the frame section (8). 8. Device according to one or more of the preceding claims, characterized in that the frame sections (8) and/<four the surfaces of the frame section supports (12) engaging with the foil are polished or the like. 9. Device according to one or more of the preceding claims for wrapping a cube- or cuboid-shaped piece of goods, characterized in that the frame sections (8) are each arranged in a corner region of the corresponding piece of goods contour in the manner mentioned above. 10. Device according to one or more of the preceding claims, in particular according to claim 9, characterized in that the frame sections (8) are each (in plan view) circularly arc-shaped in their central region over an angle (α) of approximately 90°. 11. Device according to claim 10, characterized in that the essentially circular arc-shaped section is adjoined at both ends by a section (10) which has a smaller curvature or is angled inwards. 12. Device according to one or more of the preceding claims, in particular according to claim 11, characterized in that BOEHMERT & BOEHMERT - 4 - characterized in that the frame section supports (12) (seen in plan view) each run in their two end regions (17) essentially tangentially to the curvature of the film to be stretched between them. 13. Device according to one or more of the preceding claims, in particular one or more of claims 5 to 12, characterized in that the central region {12'} of the frame section supports (12) is each recessed. ^14. Device according to claim 13, characterized in that the facing edge sections (16, 16) on the recessed part ( ^12f ) of a recessed section support (12) are rounded. 15. Device according to one or more of the preceding claims, characterized in that at least one reefing roller is assigned to one or each frame section (8). 16. Device according to claim 15, characterized in that the reefing rollers can each be moved towards or away from the frame section (8) assigned to them. 17. Device according to claim 15 or 16, characterized in that the reefing rollers are each arranged in the upper region of a frame section support (12). 18. Device according to one or more of the preceding claims, characterized in that the frame sections (8) are to be moved apart in a manner known per se in order to increase their mutual distance for the purpose of horizontal stretching of the film hood (2). &bull; &diams; * · &psgr; « BOEHMERl & BOEHMERT'' 19. Device according to one or more of the preceding claims, characterized in that at least two adjacent frame sections (8, 8) are telescopically connected to one another. 20. Device according to claim 19, characterized in that all frame sections (8) are each telescopically connected to the adjacent frame sections (8, 8).