CA1043691A

CA1043691A - Band wrapping machine

Info

Publication number: CA1043691A
Application number: CA258,107A
Authority: CA
Inventors: Fritz Noack; Rolf Wenger
Original assignee: Emil Pester Platinen und Apparatefabrik
Current assignee: Emil Pester Platinen und Apparatefabrik
Priority date: 1975-07-31
Filing date: 1976-07-29
Publication date: 1978-12-05
Also published as: AU514274B2; AU1622676A; SE7608498L; JPS5635575B2; NL7608346A; ES450227A1; GB1514675A; NL181571C; IT1068199B; ATA542576A; CH608448A5; FR2319527A1; FR2319527B1; DD125064A5; SE429034B; NL181571B; AT346774B; JPS5249191A; DE2534157A1

Abstract

ABSTRACT OF THE DISCLOSURE
A foil band wrapping machine, wherein a foil band loop is formed around the articles to be wrapped and a tightening device is provided for tightening up the foil band loop. The tightening device consists of a rotatable roller having a slit which is parallel to the axis of the roller. The foil band is passed through the slit. With rotation of the roller in the first phase an automatic clamping or binding of the foil band on the roller takes place and during the continuously following phase the foil band loop is thightened up.

Description

1~)43~91 The present invention relates to a band wrapping machine for wrapping objects with a foil wrapping. Such a machine has a slider member for pushing forward the articles on a feed supply table up to a hanging of foil to form a foil loop and a tighten-ing up device to render the foil loop tight. It has also a bind-ing device to bind together the two foil parts which are adjacent one another, and which in the foil loop are touching one another, with a separating-welding device for welding of the foil loop and parting off from the foil remainder.
According~to the present invention there is provided a machine for wrapping objects with a foil wrapping, as said objects are being advanced, said machine comprising: at least one foil E
supply roller ror supplying a web of foil; two clamping elements disposed on either side of the path of movement of the objects, said clamping elements when in the clamping position grip two overlapping portions of a foil loop formed to encase said objects;
means for joining the two foil portions; separating means for separating the joined foil wrapping from the rest of the foil supply, tension means for engaging and drawing the foil loop taut around the objects, said tension means being mounted on one side of the path of the objects at a distance from said clamping ele-ments and being defined by a single rotatable roller disposed be-tween the supply roller and the foil loop having an axial passage formed therein being traversed by the foil; said roller being fur-, ther defined by a first position in which the foil extends sub-Y~ stantially without obstruction from said supply roller through r said passage to the foil loop as objects advance, and driving means connected to said roller for rotating said roller in a direction to a second position causing the foil to be clamped and the foil loop tensioned and for repositioning said roller back to ` said first position when the clamping elements are held in their clamping position.

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lV~91 An advantage oE the present invention is that there is no need for the tightening device to have its own clamping arrangement with an associated drive. During the initial move-ment of the tightening device the aperture is adjusted in its mounting so that secure clamping of the foil automatically occurs without the need for an additional drive or gears for adjustment of the aperture width. 9 The invention will now be described in more detail by way of example only with reference to the accompanying drawings, -10in which:
Figures 1 and 2 are respectively side and end views of a wrapping machine according to the invention;
Figure 3 is a side view of a tightening device on a larger scale and with the tightening up roller disposed in the plane of the feed table;
Figure 4 is a side view of the tightening roller in its tightening position; t . Figure 5 is a view in perspective of a modified embodi- ;
:~; ment of the tightening device; and i.
~i 20 Figures 6 and 7 are diagrammatic views of a further embodiment of a tightening device before and after the tightening process. . ~;
In the drawings, articles 3 which are to be wrapped are pushed alony a slider 2 of a band wrapping machine feed supply table 1 against a web of foil which is fed from an upper foil . roller 5 and a lower foil roller 6. Owing the forwards movement of the articles, the web of foil 4 becomes wrapped around the articles 3 in a loop and thereafter a pneumatically actuated :
. binding or clamping beam member 7 to the,rear of the pushed articles 3 is displaced downwardly. Prior to this bindin.g beam 7 coming into contact with a two-part counter beam 8, the tight- 1 ening up process is commenced. The commencement of the , , .

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In the embodiment in accordance with Figs. 1 to 4 the tigntening up device is forr,led from a roller 10 with a slit 11 which is parallel to the axis, contînuous throughout its extent and preferably eccentrically disposed. The web of foil 4 coming from the foil roller 6 is passed through the slit 11 of the rol-ler 10 and then proceeds to the binding zone of the two binding beams 7,8. There is becomes, with previous band wrapping process, welded to the foil web from the upper supply roller 5. The rol-ler 10 is positioned in mountings 12 of a machine frame 13 and has at one side a chain wheel- 14. Around this runs a chain 15 of l which one end is fastened to a tensioning spring 16 and the other 2 ', end to the piston rod of a compressed air cylinder 17.
In place of the chain wheel 14 and chain 15 there can be used a pulley and pulley belt or the like. Also the compressed air cylinder 17 may be replaced by an electrical linear motor for axial movement of a tie rod. ~, In the initial position of the roller 10 the aperture f ' 11 forms an obtuse angle with the lower web of foil and likewise, with the upper web of foil an obtuse angle (Figure 3), or may proceed as a linear ext,ension with the upper run of foil (Figure 1). On entry and exit of the web of foil in respect to the aper-, ture 11, the foil web is not to be too sharply inclined so that there is only slight braking of the web of foil in the formation of the foil loop.
With rotation of the roller lO due to air pressure in ~, 30 the compressed air cylinder 17 there is then set in train the first movement phase in the automatic binding. This is initiated ` after a small angle of rotation has taken place, namely at about .
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when at least one of the incoming and outgoing webs of foil makes an angle of approaching 90 degrees with the aperture 11. The following further rotation of a roller 10 in a' counter-clockwise direction brings about the tightening up process. The final yosition can be seen from Fig. 4. The roller has undergone substantially a whole rotation. The angle of rotation of the roller 10 is determined by the stroke of thè compressed air cylinder 17. The pressure of the compressed air cylinder can be adjusted in known manner by means of a control valve for a pre-determined power to be exerted on the foil loop. An adjustablefoil brake 18 bears on the upper foil web with a view to prevent-ing slipping of this occurring with smooth articles 3 during ~r~ the tightening up process. , At about the same time as the final position of the roller 10 has been reached, the binding beam 7 has attained its lowermost position and clamps two mutually overlapping foil webs !~
against the counter beam 8. The separating welding process then takes place in the clamping, binding zone. Prior to this however pressure release occurs in the compressed air cylinder 17 with A~ 20 re-setting of the roller 10 through the spring 16. The binding ~ beam 7 is then raised.
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Figure 3 differs from Figure 1 essentially in that the , roller 10 is disposed directly at the table plane of the feed supply table 1 and as close as possible to the foil loop. This j~
renders possible a shorter stroke of the compressed air cylinder 17.
Figure 5 shows another form for the tightening up device.
In place of the slit roller 10 there is utilised a rod drum 19 which is formed from two endplates 20 and'for example four paral-t~
lel mutually spaced rods 21. The foil web enters through the-two upper rods and exits through the two lower rods. The functioning of the rod drum 19 is the same as that of the roller 10.

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Fic~ures 6 and 7 show a tightening up device which is ~ormed from a drive roller 22 havincJ a flattened surface 23 and a counter roller 24. In the initial position of the rollers 22, 24, the flattenin~ 23 lies up against the counter roller 24 (Fiyure 6), with formation of an aperture 25 through which the foil run 4 proceeds. When the drive roller 22 becomes rotated in a counter-clockwise direction, from the initial position indi-cated in full lines, to the dashed lines clamping position, the q foil run is securely clamped between the rollers 22, 24, as the edge of the flattening 23 bears against counter roller 24. A
further counter-clockwise rotation of the roller 22 brings about the tightening process.
To accelerate the tightening up the drive roller 22 in Figure 6 is provided with a rocker arm 26 which carries at its free end an idler roller 27. This latter moves over a cir-cular track about the rotational axis of the roller 22 so that as soon as the rotational turn of the roller 22 exceeds a small angle, the rocker arm 26 is thereby brought out of the dashed indicated position in Figure 6 into the position of Figure 7 (tightening final position).
For all embodiments given by way of example it is re-~;; quisite that the foil web proceeds in a single layer form through an aperture of a rotatable tightening up device and that for a turn angle of the tightening up device the first part, through J variation of the disposition and, or of the form of the aperture, is used for securing the foil run in the tightening device, while a second part of the turn angle is utilised for the tight-ening up process.

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Claims

THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:

1. A machine for wrapping objects with a foil wrapping, as said objects are being advanced, said machine comprising: at least one foil supply roller for supplying a web of foil; two clamping elements disposed on either side of the path of movement of the objects, said clamping elements when in the clamping posi-tion grip two overlapping portions of a foil loop formed to en-case said objects; means for joining the two foil portions;
separating means for separating the joined foil wrapping from the rest of the foil supply, tension means for engaging and drawing the foil loop taut around the objects, said tension means being mounted on one side of the path of the objects at a distance from said clamping elements and being defined by a single rota-table roller disposed between the supply roller and the foil loop having an axial passage formed therein being traversed by the foil; said roller being further defined by a first position in which the foil extends substantially without obstruction from said supply roller through said passage to the foil loop as ob-jects advance, and driving means connected to said roller for ro-tating said roller in a direction to a second position causing the foil to be clamped and the foil loop tensioned and for re-positioning said roller back to said first position when the clamping elements are held in their clamping position.

2. A machine according to claim 1, wherein: said roller in the first position is disposed to orient said passage in linear extension to form an acute angle with one of adjacent foil webs.

3. A machine according to claim 1, wherein: two foil supply rollers are provided on either side of the line of advance of said objects, the foils of which are joined with one another, a first of the foils being passed through the passage of the single roller and the second of said foils being passed through a braking device cooperatively associated with the tension move-ment of the single roller.