EP0645341B1 - Method and device for identifying and sorting of aluminium and plastic screw caps of bottles or similar containers after the unscrewing process - Google Patents

Abstract

The invention relates to a method and a device for identifying and sorting aluminium and plastic screw caps of bottles (14) and similar containers after the unscrewing process, using a rotating unscrewing machine (10) having screwing-on heads (6) which describe a circular or curved path, engage around the screw caps (13) mounted on the bottles or containers and, with simultaneous rotation, screw them off, lift them up and discharge them by, among other means, arranging for an ejection rod (11), which can be actuated by means of a radial cam (1), directly or indirectly to open the gripping device (5) of the unscrewing heads for the caps and for the latter to be released above a collecting container, by arranging for expansion of the gripping device (5) of the unscrewing heads (6) to be carried out after some delay and in stages via at least two steps in the radial cam, in such a way that in an initial phase, when the first stage of the radial cam has been reached, the aluminium screw caps of a relatively small diameter and in a second phase after further operation of the radial cam and when the second step has been reached, the plastic screw caps of a relatively large diameter are ejected into separate containers at a distance from one another corresponding to the distance between the steps. In this process, the device according to the invention has a radial cam which activates the stroke of the unscrewing heads and has at least two steps in the ejection sector, the inclination, height, length and distance between the said steps being proportional to the opening distance of the gripping device of the unscrewing heads and the distance between the at least two collecting containers. <IMAGE>

Description

The invention relates to a method and a device for detecting and sorting aluminum and plastic screw caps of bottles and similar containers after the unscrewing process, according to the preamble of claim 1 and claim 2.

Preferably in the beverage industry, the declining reusable bottles must be freed of any screw caps that may have been screwed onto the bottle mouth before further treatment. Various fully automated systems are known for this. Such a unscrewing machine is known for example from the company brochure "Adelski, Mannheim, PPE 80".

The return bottles with closures arriving on a conveyor belt are placed in a bottle sorting screw and from there they enter a bottle inlet star, which passes the bottles on to a central star via a belt guide. After the bottles are centered, the appropriate unscrewing heads lower onto the bottles and unscrew the existing closures from the bottle using a locking tool. The unscrewing heads are designed so that any incoming bottles cannot be damaged at the mouth and thread without closure. The central star then passes the bottles on to the discharge star, which forwards them to a conveyor belt running through the machine. The closures twisted off the bottles are so long in the Unscrewing heads held until they are over a catch device. Here the twisted closures are released by the unscrewing head and fall into the closure catcher.

The closures themselves are destroyed by the unscrewing head because it pierces through the closures.

In order to eject the bottle caps, a relatively high stroke is required, which depends on the height of the caps.

From the company brochure Alcoa "Unscrewing machines of the 90 series" 1989 a unscrewing machine similar principle is known. Here, too, the bottles, which are centered, run into the machine and are positioned below, concentrically positioned around a vertical axis and rotating around the unscrewing heads. During constant movement, the bottles pass through the work area, with a synchronous control unit causing the unscrewing heads to move up and down. Plier-shaped screwdriver heads are used here, which grip the bottle caps, twist them off under rotation, lift them off and eject them. The stroke of the unscrewing heads or the ejection plunger integrated therein is carried out via a corresponding control cam that is aligned with the movement sequence of the unscrewing heads.

The disadvantage of the prior art shown, however, is that these unscrewing heads or unscrewing machines are aluminum and Plastic screw caps cannot differentiate from one another. However, this is desirable and necessary due to the further recycling, since otherwise a complex sorting work will follow.

Document DE-A-2752035 discloses a method and an apparatus which correspond to the subject matter of the preambles of claims 1 and 2.

The present invention is therefore based on the object of providing a method and a device by means of which detection and sorting, that is to say differentiation between the plastic and aluminum closures, is possible during the transport flow.

This object is achieved by a method according to the characterizing part of claim 1 and by a device according to the characterizing part of claim 2.

The invention takes on the property of the different caps with regard to their size, in particular their diameter. Plastic screw caps have a larger diameter than aluminum screw caps. According to the invention, this difference in size or difference in diameter is now used to gradually eject the unscrewed caps. In unscrewing machines, after the unscrewing process, the ejection plunger is controlled downwards via a stroke curve and opens by means of a control ring that slides on the corresponding control cams, the control levers arranged there. Now the unscrewed capsule, which until now has been held by the unscrewing plates, can fall down. To according to the invention, plastic capsule of aluminum separate, an additional step is installed on the stroke curve so that the unscrewing head first opens to a dimension of 29 mm, for example. Now the aluminum locks fall out. When the second stage is reached, the unscrewing head is opened to, for example, 34 mm, so that the plastic closures are ejected. The difference in diameter of aluminum closures (28mm) compared to plastic closures (30mm) is used to sort them. If the unscrewing head unscrewed a plastic capsule, it is still held in place at the first stage (opening to 29mm). If an aluminum capsule had been unscrewed, it will be ejected in stage I. So the plastic capsule is only released at the second stage (opening 34mm).

Figur 1

einen schematischen Querschnitt durch eine Abschraubmaschine;

Figur 1a

eine Vergrößerung der Fig. 1 (linker, oberer Bereich)

Figur 1b

eine Vergrößerung der Fig. 1 (rechter, oberer Bereich)

Figur 1c

eine Vergrößerung der Fig. 1 (linker, unterer Bereich)

Figur 1d

eine Vergrößerung der Fig. 1 (Mitte, unten)

Figur 2

eine Vergrößerung des Entschrauberkopfes;

Figur 3

eine Draufsicht auf den schematischen Verlauf der Steuerkurve und

Figur 4

eine schematisch dargestellte Abwicklung der Steuerkurve.

With reference to the accompanying drawings, which show a particularly preferred embodiment of the invention, this will now be described in more detail. Show:

Figure 1

a schematic cross section through a unscrewing machine;

Figure 1a

an enlargement of Fig. 1 (left, upper area)

Figure 1b

an enlargement of Fig. 1 (right, upper area)

Figure 1c

an enlargement of Fig. 1 (left, lower area)

Figure 1d

an enlargement of Fig. 1 (middle, bottom)

Figure 2

an enlargement of the stripper head;

Figure 3

a plan view of the schematic course of the control curve and

Figure 4

a schematically illustrated execution of the control curve.

FIG. 1 shows a cross section through a unscrewing machine 10. A plurality of unscrewing heads 6 are arranged concentrically around a vertical axis 9. The unscrewing heads 6 are formed, inter alia, from the gripping device 5 and the ejection plunger 11 (5 and 11 cannot be seen). In addition to the rotation about the central vertical axis 9 of the unscrewing machine 10, the unscrewing heads 6 are also able to rotate about their own axis 12. This is important for the actual unscrewing process so that the screw caps 13 can be properly removed from the bottles 14. Prior to this, the bottles are pre-sorted and centered, then inserted into the work area of the unscrewing machine in accordance with the registration.
This is done in a known manner, for example by means of a centering star.

At the end, the unscrewing heads 6 have a guide carriage 15 which travels the cam 1. The dynamics of the control curve 1 can be seen in two places in this figure, in that in the left half of the picture the control curve in area A is higher than the control curve 1 in area B. If the guide carriage 15 works the control curve 1 concentrically around the vertical axis 9 of the unscrewing machine , this has a direct effect on the stroke behavior of the unscrewing heads 6, or their ejection plungers 11. In connection with FIG. 2, which shows an enlargement of the unscrewing head, the further process sequence can now be described further and in more detail.

For this purpose, the structural nature of the Descrewing head 6 discussed in more detail. As already explained above, a de-screwing head 6 consists of the gripping device 5 and the ejection plunger 11. The de-screwing head 6 or the gripping device 5 has a plier-like shape. In this illustration according to FIG. 2, however, only a pair of pliers is shown for the sake of simplicity.

On a bell 16 17 control levers 18 are arranged pivotable about an axis 19 within corresponding recesses. On their inside, the control levers 18 carry corresponding obliquely entering control cams 20. On the lower end side, a holding plate 21 is arranged on both sides of the control lever 18. The opposite control levers 18 are biased by the tension spring 22. The caps are now gripped and unscrewed in a conventionally known manner.

If the caps are now to be ejected, this is done via the respective position of the de-screwing head 6 on the control curve 1. Here, the cross pin 23 will strike the lower wall 24 of the elongated hole 25 on the control wall 1 during an upward stroke of the guide carriage 15, since the Move bells 16 together with piston 26 upwards and in doing so wipe the ejection plunger 11 with its control ring 27 over the control cams 20, whereby it reaches the raised cam part 29 via the bevel 28 and thus expands the gripping device 5.

According to the invention, this widening now takes place in a step-like manner, in that stages designed in accordance with the ejection behavior are incorporated into the control cam 1.

This is schematically best explained in FIGS. 3 and 4.

In addition to the usual course of the control curve, to which the first stage 3 is also to be counted, there follows a stepless movement path 30, which is followed by a second stage 4. This area is identified as ejection sector 2 as a whole.
According to the device, the collection containers are also located here, which are schematically identified by the reference numerals 7 and 8.

The development of the control curve begins with the reference symbol (I). The inlet (II) is marked in the range of 95 °, an increase above 10 ° (III) taking place beforehand.
A lowering takes place in the range of 55 ° (IV), followed by a lower curve of 80 ° (V) with an approximately 7 mm slope.
The curve continues with a 30 ° sector (VI) upwards, followed by a 70 ° outlet (VII) (top). Now there is a 10 ° step (VIII) - 10 mm rising - with a subsequent 10 ° (IX) horizontal course.

The present invention provides a method and a device by means of which, using the screw cap diameter, it is possible to recognize and sort between aluminum and plastic screw caps in order to continue to handle them separately, for example first to eject them into separate collection containers.

Reference list

1

Control curve

2nd

Ejection sector

3rd

Level I

4th

Stage II

5

Gripping device

6

Unscrewing head

7

Collection container I

8th

Collection container II

9

vertical axis of 10

10th

Unscrewing machine

11

Ejection plunger

12th

Axis of 6

13

Screw cap

14

bottle

15

Guide carriage

16

Bell jar

17th

Recesses

18th

Control lever

19th

Swivel axis

20th

Control cam

21

Holding plates

22

Tension spring

23

Cross splint

24th

bottom wall of 25

25th

Long hole

26

piston

27

Control ring

28

sloping track of 20

29

raised cam part of 20

30th

stepless movement

Claims (2)

1. Process of identifying and sorting of aluminum and plastic screw caps as used on bottles and other containers after their removal from the bottles or other containers using, for the removal, a rotating twist-off machine equipped with twist-off heads passing through a circular or trajectory course, with the screw caps applied to the bottles or containers being clutched by these twist-off heads, unscrewed in a rotating movement, lifted off, then ejected by means - among others - of an ejector tappet which, activated by a cam, directly or indirectly drives open the gripping device of the twist-off heads thus releasing the screw caps and dropping them into a collecting receptacle,
   wherein
   the gripping device of the twist-off heads is driven open, in a time-delayed and stepwise motion, by at least two stages of the cam in such a way as to enable,

   a) in a first phase, upon arriving at the first stage of the cam, the aluminum screw caps having a smaller diameter, and

   b) in a second phase, as the cam proceeds in its course and upon arriving at the second stage, the plastic screw caps having a larger diameter,

   c) to be released and dropped into separate collecting receptacles placed at a distance from each other that corresponds to the gap between the two stages of the cam.
2. Device for the execution of the process described in Claim 1 equipped with a bottle conveying line and centering devices used to accurately place the bottles (14) in an ideal seizing and clutching position below the claw-shaped twist-off heads (6), with the twist-off heads being distributed in a concentric arrangement around a vertical central axis (12) enabling them to pass through a circular or trajectory course that represents the field of action, and with the twist-off heads (6) moving up and down, the up-and-down stroke being controlled by a cam, the screw caps being twisted off the bottle (14) by a rotational movement of the twist-off heads to be subsequently discharged into a receptacle,
   wherein
   the cam (1) that controls the stroke of the twist-off heads (6) presents, in the ejection or discharge sector (2), at least two stages (3,4) the pitch, height and length of which, as well as the spacing one from another, are proportional both to the drive-open motion of the gripping device (5) of the twist-off heads (6) and to the distance at which at least two collecting receptacles (7,8) are placed from each other.

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