EP0778206A2

EP0778206A2 - Automatic device for gripping and holding flexible bag-shaped containers and by means of independent gripping units

Info

Publication number: EP0778206A2
Application number: EP95202423A
Authority: EP
Inventors: Mario Ronchi
Original assignee: RONCHI MARIO Srl OFFICINE MECCANICHE
Current assignee: Ronchi Mario Srl
Priority date: 1995-06-20
Filing date: 1995-09-07
Publication date: 1997-06-11
Also published as: IT1276757B1; ITMI951324A1; ITMI951324A0; EP0778206A3

Abstract

Automatic device for gripping and holding containers (20, 120) in the form of a bag and the like made of flexible material in particular for automatic packaging machines (100) comprising two pincer-type gripping units (9) located opposite one another and independent of one another, each of which is mounted on an associated upright (5) integral with a base (2) and movable in translation on the base itself with respect to the axis (X-X) of vertical symmetry of the container (20, 120), said gripping units being operated so as to perform a synchronized rotational movement away from and towards said axis of symmetry via first operating means (6, 8, 7, 16), cooperating with means (106) integral with the packaging machine (100), and so as to open and close via second operating means (11, 10, 18b, 18), cooperating with associated means (111) integral with the machine (100) and acting against the recall action of elastic elements (12).

Description

The present invention relates to an automatic device for container packaging machines which is designed to perform gripping and holding of flexible bag-shaped containers during the entire packaging cycle, said device being provided with means independent of one another for adjusting the relative distance of each gripping element with respect to the vertical axis of symmetry of the container itself.
It is known how the technology for the packaging of liquid or solid products is oriented, among other things, towards the production and packaging of flexible containers made in the form of bags or the like provided with a bottom designed to expand, following filling of the containers, so as to form, when the package is full, a stable support base for the container itself.
In this technology it is also known of automatic plants designed to produce said containers from a roll of film material consisting of plastic or like and to fill and hermetically close the containers: these plants are substantially composed of a first apparatus for forming the container and a second apparatus, arranged in series with the first one, in which the container is filled and sealed.
An example of this type of plant is for example described in the Patent Application IT-001409 in the name of the same Applicant.
This type of plant, although envisaging that the filling and sealing machine should function with the continuous feeding of the containers, has some drawbacks due to the fact the means for gripping and holding the containers themselves are integral with the individual filling and sealing carousels respectively, thereby making it necessary to pick up and release several times the container itself during its travel path inside the machine.
In addition to this, the upper part of the said containers is shaped in widely varying forms so as to provide for example handles, bottle-necks and the like, this variety of configurations which may also be asymmetrical with respect to the vertical axis of the container requiring the replacement of the known gripping devices which do not envisage independent adjustment of the distance of the gripping elements with respect to the said axis of symmetry.
The technical problem which is posed, therefore, is that of providing a device for gripping and holding containers in the form of a bag or the like made of flexible material, which is suitable for coupling to means for transporting the containers themselves inside packaging machines and operation of which can be effected by means of suitable elements integral with the machine so as to achieve holding of the containers and facilitate opening/closing of the mouth thereof during the various stages of packaging.
Within the scope of this technical problem it is also required that the gripping elements should be able to perform a translatory movement, independently of one another, with respect to the axis of vertical symmetry of the container so as to ensure carrying out of the said gripping, opening and closing operations also for containers which are asymmetrical and have different widths, without the need for replacement of the entire unit.
It is required, moreover, that said gripping devices should be easy and economical to install and be able to be supplied by means of suitable container loaders coupled to the machine.
These results are obtained by the present invention, which envisages an automatic device for gripping and holding containers in the form of a bag or the like made of flexible material in particular for automatic packaging machines, which comprises two pincer-type gripping units located opposite one another and independent of one another, each of which is mounted on an associated upright integral with a base and movable in translation on the base itself with respect to the axis (X-X) of vertical symmetry of the container, said gripping units being operated so as to perform a synchronized rotation away from and towards said axis of symmetry via first operating means, cooperating with means integral with the packaging machine, and so as to open and close via second operating means, cooperating with associated means integral with the machine and acting against the recall action of elastic elements, said first and second actuating means causing the symmetrical movement of the pincers towards/away from the axis (X-X) of vertical symmetry of the container and closing/opening of the pincers themselves in order to hold the container and cause opening/closing of the mouth thereof during the filling and sealing phases.
Further details can be obtained from the following description, with reference to the accompanying drawings, in which:

Figure 1 shows a partially sectioned side view of the gripping device according to the invention in the open position and mounted on a rotating packaging machine;
Figure 2 shows a partially sectioned plan view of the gripping device according to Figure 1;
Figures 3a, 3b and 3c show, respectively, a partially sectioned side view, a front view and a plan view of the gripping device during insertion of a symmetrical bag;
Figures 4a, 4b and 4c show, respectively, a partially sectioned side view, a front view and a plan view of the gripping device during gripping of the bag;
Figures 5a, 5b show, respectively, a front view and plan view of the gripping device during opening of the bag;
Figures 6a and 6b show a front view of the device during the phases, respectively, of gripping and opening of an asymmetrical bag.

As shown in the figures, the automatic gripping device 1 according to the invention comprises a substantially flat support base 2 integral with a shank 2a of square cross-section extending underneath the said base 2 and fixed to a disc 101 rotating about an axis of rotation 101a of a packaging machine shown only schematically by 100.
For the sake of simplicity of the description, below the internal part of a component will be defined as being that closest to the axis of rotation and the external part as that furthest from the latter.
The upper surface of the base 2 has mounted on it travel rollers 2a designed to engage with the opposite surfaces of a guide rail 102a integral with a fixed disc 102 of the machine 100: in this way the gripping devices 1, arranged at predetermined angular distances on the rotating disc 101, are able to rotate together with the latter, travelling on the fixed guide 102a and passing underneath the various stations of the machine 100.
The edge of the base 2 which is external with respect to the axis of rotation of the machine 100 is formed in the manner of a dovetail cross-section 2b onto which are inserted the bottom ends of a fixed central upright 4 and two lateral uprights 5 which slide independently of one another on the dovetail 2b and can be locked on the latter in different positions.
The central fixed upright 4 is shaped in the manner of an upturned "U" and the internal short branch of the "U" directed downwards is formed by small cylinders 4a, the bottom free end of which terminates in end-of-travel discs 4b for a horizontal rail 6 sliding in the vertical direction on the said small cylinders 4a actuated by cam means 106 integral with the machine 100 and designed to come into contact with a roller 6a mounted on an arm 6b extending from the rail 6 towards the axis of rotation of the machine.
On the outer side the rail 6 has a C-shaped cross-section designed to form the guide 6c for travel of a roller 8a described in more detail below.
Each lateral upright 5 supports a horizontal hollow shaft 7: the internal end of said hollow shaft is connected to a rotational actuating arm 8, the free end of which has mounted on it the said roller 8a travelling on the said rail 6.
The external end of the hollow shaft 7 carries, on the other hand, the unit 9 forming the actual pincer.
The hollow shaft 7 has arranged inside it, coaxially with respect thereto, a rod 10 free to slide relative to the hollow shaft 7 and pushed by a cross-piece 11 actuated by cam means 111 integral with the machine 100 against the recall action of elastic means 12 described more fully below.
The external end of the rod 10 terminates in a base-piece 10a, while at the internal end of the rod 10 there is arranged a block 14 provided with an inclined-surface tooth 14a designed to cooperate with a corresponding and complementary projection 15a of a rocker element 15 rotatable about a horizontal pin 15b against the thrusting action of a resilient lamina 15c.
As mentioned, the external end of the hollow shaft 7 carries the pincer unit 9 substantially consisting of a horizontal arm 16 intergal with the hollow shaft 7 with which it is able to rotate and carrying on the opposite side a vertical block 17 externally shaped so as to form the fixed jaw 17a of the pincer.
The block 17 has housed inside it a spindle 18, the opposite ends of which have fixed to them, respectively, an upper and lower horizontal arm- piece 18a and 18b forming the movable jaws of the pincer and the associated means for transmission of the closing/opening movement imparted, as described in more detail below, via the rod 10 and the base-piece 10a.
As illustrated in Fig. 1, the bottom arm-piece 18b has hooked to it one end 12b of the said spring 12, the other end 12a of which is hooked to the bottom part of the arm 16.
Operation of the device is as follows:
Assuming that the bag 20 is symmetrical, the lateral uprights 5 are arranged symmetrically with respect to the axis of symmetry X-X of the bag and at a suitable distance from one another.
During this first phase, the cross-piece 11 is not pressed outwards by the cam 111, therefore the action of each spring 12 recalls the associated bottom horizontal arm-piece 18b which, pressing on the base-piece 10a, causes retraction of the rod 10 and opening of the movable jaw 18a; during this phase, the rail 6 is pushed upwards by the cam 106, the arms 8 are therefore (Fig. 3b) rotated in an anti-clockwise direction, causing a similar rotation of the hollow shaft 7 and hence the rotation, in an anti-clockwise direction, of the arm 16 which brings the pincers into the position where they are located at the greatest distance from one another so as to allow the free entry, in the radial direction, of the bag 20 supplied (Fig. 3c) by a loader not shown.
During the next phase (Figs. 4a, 4b, 4c), the cam 106 coming into contact with the roller 6b of the rail 6 causes a first lowering movement thereof on the guides 4a, causing the rotation, in a clockwise direction, of the arm 8 and hence the hollow shaft 7 and the arm 16 which carries the jaws still open on the bag 20; at the same time the cam 111 acts on the cross-piece 11 pushing it outwards until the tooth 14a exceeds the projection 15a which, returning into the horizontal position pushed by the resilient lamina 15c, locks the rod in the position where it is pushed outwards, causing the stable closure of the movable jaws 18a against the fixed jaws 17a and hence the stable gripping of the upper edges of the bag 20. Continuing its rotation, the disc 101 conveys the bag to the filling station and before the travel has been completed opening of the mouth 20a of the bag is obtained (Figs. 5a, 5b) by means of further lowering of the rail 6 until it comes up against the end-of-travel stop 4b, this lowering movement causing a further rotation of the arms 8 and hence the arms 16 which bring the pincers 9 into the position where they are located at a mininum relative distance with respect to the axis X-X of symmetry of the bag, forcing the latter to open.
Continuing its rotation, the disc 101 must convey the bag to the sealing and the unloading points and therefore the pincers will be actuated during this travel section in accordance with a sequence exactly opposite to that described above in order to obtain reclosure of the mouth 20a for sealing thereof and opening of the pincers for removal of the bag 20 by a loader not shown.
As shown in Figs. 6a, 6b, with the gripping device according to the invention it is also possible to transport bags 120 which are asymmetrical, for example on account of a lateral chamfer 120b: in this case it is sufficient to slide the corresponding lateral upright 5 on the dovetail 2b of the base 2 until it is brought into the appropriate position closer to the axis of symmetry X-X of the bag 120 itself.
All the other operations performed by the device thus remain unaltered.
It is obvious how the device according to the invention allows bag-shaped containers of the most varied shapes and sizes to be handled automatically without having to provide special pincer configurations for each type, thus avoiding production downtimes associated with retooling of the packaging machine.
Many variants may be introduced as regards the realization of the component parts of the invention, without thereby departing from the protective scope of the present invention as defined in the claims which follow.

Claims

Automatic device for gripping and holding containers (20, 120) in the form of bags and the like made of flexible material in particular for automatic packaging machines (100), characterized in that it comprises two pincer-type gripping units (9) located opposite one another and independent of one another, each of which is mounted on an associated upright (5) integral with a base (2) and movable in translation on the base itself with respect to the axis (X-X) of vertical symmetry of the container (20, 120), said pincer-type gripping units being operated so as to perform a synchronized rotation away from and towards said axis of symmetry via first operating means (6, 8, 7, 16), cooperating with means (106) integral with the packaging machine (100), and so as to open and close via second operating means (11, 10, 18b, 18), cooperating with associated means (111) integral with the machine (100) and acting against the recall action of elastic elements (12), said first and second actuating means causing the symmetrical movement of the pincers towards/away from the axis (X-X) of vertical symmetry of the container (20, 120) and closing/opening of the pincers themselves of the gripping units in order to hold the container and cause opening/closing of the mouth (20a, 120a) thereof during the filling and sealing phases.
Device according to Claim 1, characterized in that said fixed base (2) supporting the pincer-type gripping units (9) has its external edge (2b) in the form of a dovetail so as to allow translation of the uprights (5) carrying the gripping units (9) away from and towards the axis of symmetry (X-X) of the container.
Device according to Claim 1, characterized in that said pincer units (9) are substantially formed by a vertical element (17), the upper end of which forms the fixed jaw (18a) of the pincer and which has coaxially arranged inside it a spindle (18) carrying on its upper end the movable jaw (18a) of the pincer and on its lower end an arm-piece (18b), parallel to the former, for actuating opening/closing of the said movable jaw (18a).
Device according to Claim 1, characterized in that each pincer-type gripping unit (9) is mounted on an arm (16) which can be actuated so as to perform a rotational movement about a horizontal axis via said means (6, 8, 7, 16) performing rotation away from and towards the axis of symmetry (X-X) of the bag (20, 120).
Device according to Claim 1, characterized in that said first means (6, 8, 7, 16) performing rotation of each pincer unit consist of a substantially horizontal rail (6), movable in translation in the vertical direction under the thrusting action of said means (106) integral with the machine (100), and of an arm (8), the opposite ends of which are respectively slidably mounted on the rail (6) and integral with a hollow shaft (7) carrying the said arm (16) supporting the pincer unit (9), translation of the rails in either direction causing the corresponding rotation of arm (8), hollow shaft (7) and pincer unit (9) in the clockwise and anti-clockwise direction.
Device according to Claim 1, characterized in that said second means (11, 10, 18b, 18) performing opening and closing of the jaws (18b) consist of a rod (10), coaxial with the hollow shaft (7), the opposite ends (11, 10a) of which are respectively actuated so as to perform a synchronized translatory movement by the said means (11) integral with the machine (100) and acting so as to push the said bottom arm-piece (18b) against the recall action of the said elastic means (12).
Device according to Claim 1, characterized in that said means (106, 111) integral with the machine and acting on said first and second means operating the gripping device consist of cams.
Device according to Claim 1, characterized in that means are provided for reversibly locking the rod (10), consisting of an element (14) integral with the rod (10), shaped in the manner of a tooth (14a) and cooperating with a corresponding and complementary projection (15a) on a rocker (15) which is held in position by a resilient lamina (15c) and can be released by cam means integral with the machine.
Device according to Claim 1, characterized in that said elastic means consist of a spring extending between the upright (5) and the bottom arm-piece (18b) of the pincer.
Device according to Claim 1, characterized in that said bags are symmetrical with respect to the axis of symmetry (X-X).
Device according to Claim 1, characterized in that the top part of said bags is asymmetrical with respect to the axis of vertical symmetry (X-X).