WO2011121624A1

WO2011121624A1 - Gripping device for containers

Info

Publication number: WO2011121624A1
Application number: PCT/IT2010/000143
Authority: WO
Inventors: Gianluca Pongolini
Original assignee: Sidel S.P.A. Con Socio Unico
Priority date: 2010-04-02
Filing date: 2010-04-02
Publication date: 2011-10-06

Abstract

There is described a gripping device (1; 1') comprising a first (4) and a second (5) swivelling levers adapted to contact a container (2) on opposite sides thereof, having respective swivelling axes (B, C) and being rotationally linked to one another, the first and second swivelling levers (4,5) and their respective swivelling axes (B, C) being arranged symmetrically with respect to a plane (S); a counteraction swivelling lever (8) having a respective swivelling axis (E), being rotationally linked to the first and second swivelling levers (4,5) and extending along a direction intersecting said plane (S); said swivelling axes (B, C, E) all lying on the circumference of a circle (10), said plane (S) defining at its intersection with a plane orthogonal to said swivelling axes (B, C, E) a first diameter (Dl) of said circle (10); and said counteraction swivelling lever (8) and at least one of said first and second swivelling levers (5) and their respective swivelling axes (C, E) being arranged symmetrically with respect to a second diameter (D2) of said circle (10).

Description

GRIPPING DEVICE FOR CONTAINERS

TECHNICAL FIELD

The present invention relates to a gripping device for containers, in particular for containers having an at least partially circular cross-section, such as bottles.

More particularly, the invention relates to a gripping device which may be mounted on a container- processing machine, such as a filling machine, a rinsing machine, a labelling machine and the like.

BACKGROUND ART

As it is generally known, gripping devices for containers, e.g. for bottles, are used on container- processing machines for gripping the containers. In the gripped position, containers can be conveniently conveyed, filled, sealed, labelled and so forth.

Especially when processing bottles of a thermoplastic material, such as PET, gripping devices are designed to grip the bottles at their neck portion, which is commonly provided with a reinforced collar adapted to this purpose.

A disadvantage inherent with certain gripping devices known in the art is that they are suitable only for one specific container size. As a consequence, when containers , having a different size have to be processed, all gripping devices on the container-processing machine shall have to be replaced by corresponding gripping devices of a different size.

Other more recently developed gripping devices, on the other hand, can be adapted to grip bottles having different sizes. However, in order to compensate for an increased/decreased size, the position of the container relative to the gripping device is adjusted, hence the very position of the centre of the container is slightly shifted depending on its size. This is highly undesirable, since the container in the gripped position is to align or, at least, partially engage with the portion of the machine responsible for a certain process, e.g. a machine portion bearing a labelling device, or a filling/rinsing head, etc.

Gripping devices are known from US 7661739 and US2009/0020394 which comprise three swivelling levers for gripping a container by contacting its surface at three distinct positions, the swivelling levers being kinematically linked to one another.

More particularly, one of the swivelling levers is rotationally coupled to the other levers in counter- rotation direction, so that the gripping levers can only execute pre-determined movements relative to each other. Furthermore, one of the swivelling levers is arranged so as to contact the container at a position between the container and the swivelling axes, in order to prevent the container from slipping towards the swivelling axes.

Finally, at least two of the levers have a contoured grip surface by which a single lever may grip the container at at least two separate positions at a time, with a view to positioning the centre of containers having different sizes always in the same location in relation to the swivel bearings of the levers.

However, while the levers of the gripping devices known from US 7661739 and US2009/0020394 engage with the container surface at a plurality of positions about its circumference, pressure on the container is generally not evenly distributed, particularly when the device is used for gripping containers having a size greatly larger/smaller than the average container size for which the device is designed.

In fact, for each different size of the container to be gripped, the force applied to the container by the swivelling lever contacting the container in a position between the container and the swivelling axes shall be directed along a different axis, generally not parallel to the symmetry axis of the other swivelling levers.

Consequently, this force shall generally be only partly balanced by the forces exerted on the container by the other swivelling levers, the gripping device as a whole thereby subjecting the container to a force tending to shift it off its ideally aligned position.

Furthermore, this non-uniform distribution of forces about the circumference of the container may cause an at least partial local deformation of the container being gripped, unless the neck portion thereof is suitably reinforced .

The residual tendency to shift the container off its ideally centred position, together with the potential occurrence of local deformation of the gripped portion of the container may lead to undesirable problems when the container has to be passed from one container-processing machine to another .

In addition, it must be noted that the manufacture of containers from recycled plastics is becoming more and more frequent. These materials comply with all health requirements and substantially maintain the workability properties, of their as-synthesised counterpart. However, containers manufactured therefrom have been found to be more prone to being irreversibly marked (e.g. scratched) as a consequence of any rough rubbing of their surface against the levers of gripping devices, or against other moving parts, as may be caused by an imprecise positioning of the container {e.g. when a container is transferred from one machine to another) .

Therefore, the need is felt in the art for a gripping device by means of which the likelihood of deformation of the containers being gripped is significantly reduced and whereby a more precise alignment of the container being gripped with a processing (i.e. labelling, filling, rinsing, etc.) machine is consistently ensured, regardless of the size of the container, and particularly when this is considerably greater/smaller than the average container size for which the gripping device is designed.

DISCLOSURE OF INVENTION

It is therefore an object of the present invention to provide a gripping device designed to achieve the above in a straightforward, low-cost manner and with a limited mechanical complexity.

Another object of the invention is to provide a container-processing machine having corresponding gripping devices .

This object is achieved by the present invention, according to which there is provided a gripping device as claimed in Claim 1.

BRIEF, DESCRIPTION OF THE DRAWINGS

In the following, a number of preferred, non- limiting embodiments of the present invention will be described by way of example with reference to the accompanying drawings, in which:

Figure 1 shows a schematic plan view of a gripping device in accordance with the teachings of the present invention gripping a container of diameter dl;

Figure 2 shows a schematic plan view of the gripping device of Figure 1 gripping a container of diameter d2 greater than dl;

Figure 3 shows a plan view of an alternative of the gripping device according to the present invention;

Figures 4 and 5 show two views in perspective from different view-points of the gripping device of Figure 3; and

Figure 6 shows a plan view of a further alternative of the gripping device according to the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Number 1 in Figure 1 indicates as a whole a gripping device for gripping a container 2, particularly a bottle, the container 2 having a longitudinal axis A and a top neck portion 3 substantially coaxial with axis A, the axis A further defining a centre Z of the neck portion 3 of the container 2.

The gripping device 1 comprises a first and a second swivelling levers 4,5 adapted to contact the container 2 on opposite sides thereof, having respective swivelling axes B and C and being rotationally linked to one another by means of respective gearwheel segments 6,7.

The first and second swivelling levers 4,5 and, in particular, their respective swivelling axes B,C are arranged symmetrically with respect to a plane S. Preferably, the first and second swivelling levers 4,5 are substantially specular.

The .gripping device 1 further comprises a counteraction swivelling lever 8 having a respective swivelling axis E, being rotationally linked to the first and second swivelling levers 4,5 by means of a respective gearwheel segment 9 and arranged in such a way that it extends in a direction intersecting the symmetry plane S.

In the embodiment shown in the Figure, the counteraction swivelling lever 8 intersects not only the symmetry plane S, but also the second swivelling lever 5 and is rotationally coupled directly to the latter by means of gearwheel segment 9, which engages the gearwheel segment 7.

Advantageously, all three swivelling axes B, C and E lie on the circumference of a circle 10 of centre P and radius R. It must be noted that the symmetry plane S defines, at its intersection with the swivelling plane of the swivelling levers 4, 5 and 8, a first diameter Dl of circle 10, upon which the centre point P lies.

Furthermore, the second swivelling lever 5 and the counteraction swivelling lever 8 and, in particular, their respective swivelling axes C,E are arranged symmetrically with respect to a second diameter D2 of the circle 10 and, consequently, to the centre point P thereof .

With the first and second swivelling levers 4,5 and the counteraction swivelling lever 8, the container 2 may be gripped at at least three positions about its surface.

The swivelling levers 4, 5 and 8 may be swivelled to open or to close about a container 2. More particularly, the swivelling levers 4, 5 and 8 are designed so that they can be swivelled in synchronisation outwardly, i.e. away from the centre point P, but can also be swivelled in synchronisation toward the centre point P, at which the container being gripped shall be positioned. In particular, in the absence of a container 2, the swivelling levers 4, 5 and 8 can be swivelled inwardly to a closed configuration of the gripping device 1.

Furthermore, as shown in Figures 1 and 2, swivelling levers 4 , ' 5 and 8 are adapted to grip containers of different sizes.

As will become apparent from the following analysis, due to the mutual geometric arrangement of the swivelling levers 4, 5 and 8 and of their respective swivelling axes B, C, E about the circumference of circle 10, with the symmetry relations set forth above, the gripping device 1 shall always position the container 2 being gripped, regardless of its size (diameter) , with the centre Z of the neck portion 3 centred at centre point P.

In fact, a container (bottle) 2 being gripped at its neck portion 3 between the first and second swivelling levers 4, 5 shall have its outer (circular) surface tangent to both first and second swivelling levers 4, 5. The diameter Dl of circle 10 is the symmetry axis of the first and second swivelling levers 4, 5, hence it is also, by definition, the locus of the centres of all circumferences of any diameter tangent to both first and second swivelling levers 4, 5. As a consequence, the centre Z of the neck portion 3 shall necessarily lie on the diameter Dl, regardless of the size of container 2 (see Figures 1 and 2) .

At the same time, the container (bottle) 2 being gripped at its neck portion 3 between the second swivelling lever 5 and the counteraction swivelling lever 8 shall have its outer (circular) surface tangent to both swivelling levers 5 and 8. The diameter D2 of circle 10 is the symmetry axis of the swivelling levers 5 and 8, hence it is also, by definition, the locus of the centres of all circumferences of any diameter tangent to both swivelling levers 5 and 8. As a consequence, the centre Z of the neck portion 3 shall necessarily lie on the diameter D2 , regardless of the size of container 2 (see Figures 1 and 2) .

It appears, therefore, that the centre Z of the neck portion 3 shall necessarily lie on both diameters Dl and D2 at once. By definition, the centre point P is the sole point diameters Dl and D2 have in common, hence the centre Z of the neck portion 3 of a container 2 being gripped by the swivelling arms 4, 5 and 8 of a gripping device according to the invention shall advantageously always be positioned and held at the centre point P.

Given the particular mutual geometric arrangement described above, the swivelling levers 4, 5 and 8 shall apply respective gripping forces to the container 2 along respective directions all passing by the centre point P, hence the container shall be subjected to substantially no torque .

Figures 3 to 5 show an alternative embodiment of a gripping device according to the invention, indicated by reference 1' . The gripping device 1' is similar to the gripping device 1, and is described below only insofar as it differs from the latter, and using the same reference numbers, where possible, for identical or corresponding parts of the gripping device 1.

More specifically, the gripping device 1' differs from the gripping device 1 in that it comprises a second counteraction swivelling lever 11 having a respective swivelling axis F, being rotationally linked to the first and second swivelling levers 4,5 and to the first counteraction swivelling lever 8 by means of a respective gearwheel segment 12 and arranged in such a way that that it intersects at least one of the swivelling levers 4,5.

More particularly, as shown e.g. in Figure 3, the second counteraction swivelling lever 10 intersects the first swivelling lever 4 and is rotationally coupled directly to the latter by means of gearwheel segment 12, which engages the gearwheel segment 6.

Advantageously, also the swivelling axis F of the second counteraction swivelling lever 11 lies on the circumference of the circle 10.

Furthermore, the first swivelling lever 4 and the second counteraction swivelling lever 11 and, in particular., their respective swivelling axes B,F are arranged symmetrically with respect to a third diameter D3 of the circle 10 and, consequently, to the centre point P thereof .

As a matter of fact, it shall appear from the above (see Figure 3) that also the first and second counteraction swivelling levers 8 and 11 and their respective^' swivelling axes E and F are arranged symmetrically with respect to a fourth diameter D4 of the circle 10 and, consequently, to the centre point P thereof .

As a consequence, the geometric considerations made above with reference to the interaction and mutual arrangement of the container 2 being gripped and the pairs of swivelling levers 4,5 and 5,8, shall apply, in analogous fashion, to the pairs of swivelling levers 4 , 11, and 8,11. Therefore, the centre Z of the neck portion 3 of a container 2 being gripped by the gripping device 1' shall necessarily lie on all symmetry diameters Dl, D2 , D3 and D4 at once. By definition, the centre point P is the sole point all diameters of a circle have in common, hence the centre Z of the neck portion 3 of a container 2 being gripped by the swivelling arms 4, 5, 8 and 10 of gripping device 1' according to the invention shall advantageously always be positioned and held at the centre point P.

Furthermore, due to the particular mutual geometric arrangement described above, the swivelling levers 4, 5, 8 and 11 shall apply respective gripping forces to the container .2 along respective directions all passing by the centre point P, hence the container 2 shall never be subjected to any torque. In addition, given the symmetric arrangement described above, all components of all forces applied by the swivelling levers 4, 5, 8 and 11 to the container 2 shall be substantially balanced by a corresponding counterpart having the same modulus and opposite direction, hence the resulting force acting on the container shall be substantially null.

As shown in Figures 3, 4 and 5 with particular reference to the alternative embodiment described above, which is,, however, taken by way of non limitative example, the swivelling axes B, C, E and F of the corresponding swivelling levers 4, 5, 8 and 10 are formed by threaded bolts 13b, 13c, 13e and 13f, which are releasably fixed, e.g. screwed, to a base plate 14.

Advantageously, the arrangement described above favours the opening of the gripping device 1' , which is conveniently initiated by the torque applied to the first swivelling lever which comes into contact with the container 2 to be gripped.

Preferably, the gripping device of the invention comprises an elastic means 15, e.g. a compression spring, operatively coupled with the first and second swivelling levers 4, 5 at respective end portions thereof and such that, when the elastic means is in a respective non- stressed condition, the gripping device 1, 1' is held in its closed configuration. On the other hand, when the elastic means 15 is stressed, e.g. when the container 2 to be gripped first comes into contact with either swivelling lever 4 or 5 and therefore applies a torque to the latter, the gripping device 1, 1' shall at least partially open to accommodate the container 2 in the centred position defined by the centre point P, only to then substantially close again about the container 2 to grip it and held it in the centred position.

Alternatively, a pair of swivelling arms other than the first and second swivelling arms 4,5 may be coupled by the elastic means 15.

As a further alternative, a cam system (not illustrated) may be used instead of the elastic means 14.

Yet another alternative of the invention is illustrated in Figure 6, wherein a gripping device is identified by reference 1' ' .

The gripping device 1' ' is similar to the gripping device 1' of Figures 3, 4 and 5, and is described below only insofar as it differs from the latter, and using the same reference numbers, where possible, for identical or corresponding parts of the gripping device 1' .

More specifically, the gripping device 1'' differs from the gripping device 1' in that one of the first and the second swivelling levers 4,5 comprises a projecting portion 40, extending on the side opposite a container contacting portion 41 of the swivelling lever 4,5 with respect to the relative swivelling axis B,C. Furthermore, the projecting portion 40 bears at its end portion 42, rotationally coupled therewith, e.g. by means of a corresponding pin, a cam-follower roller 43, i.e. a roller which is operationally couplable, in use, with a cam surface (not shown) so as to follow it.

Thus, in use, cooperation of the roller 43 with a corresponding cam surface suitably designed and borne, e.g. by another portion of a container processing machine on which the gripping device 1'' is mounted, shall result in a torque being applied to the swivelling lever 4,5 bearing the roller 43, thereby stressing the elastic means 15 and causing the gripping device 1'' to open. This arrangement may advantageously used for obtaining a cyclical opening/closing of the gripping device 1' ' .

The kinematic coupling of the swivelling arms 4, 5, 8, 11 of the gripping device 1, 1' may, as an alternative, be achieved by means of connecting rods, functionally replacing the gear segments 6,7,9,12 described above .

Advantageously, the gripping device of the invention may be mounted on a container-processing machine (not shown) such as a labelling machine, a filling/rinsing machine, a conveying machine, etc.

Preferably, a container-processing machine shall comprise a plurality of gripping devices 1, 1' arranged about the circumference of a carousel.

The advantages of the gripping device 1 according to the present invention will be clear from the above description.

In particular, as a result of the mutual arrangement of the swivelling levers of the gripping device of the invention and, consequently, of the positions at which forces are applied on the container, the resulting torque on the container is always substantially null, hence the likelihood of the container surface being deformed, marked or scratched, either by the gripping device itself, or by a portion of a container-processing machine with which the gripped container interacts, is significantly reduced.

Furthermore, at least in all embodiments comprising an even number of swivelling levers mutually arranged according to the teachings of the invention, even the resulting force applied by the gripping device on the container shall always be substantially null, thereby further reducing the likelihood of local deformation of the container being gripped, even when the neck portion of the container is not particularly reinforced. Finally, regardless of the size (diameter) of the container being gripped, the gripping device of the invention shall always position the container at a centred position, which is particularly advantageous when optimum alignment is required for correct operation of the container-processing machine (e.g. when rinsing or filling a container) , and even more so when interaction between two container-processing machines is required {e.g. when a container is to be transferred from one container-processing machine to another) .

Clearly, changes may be made to the gripping device 1 as described and illustrated herein without, however, departing from the scope of protection as defined in the accompanying claims .

Claims

1) A gripping device (1; 1') for gripping a container (2) , comprising

- a first (4) and a second (5) swivelling levers adapted to contact the container (2) on opposite sides thereof, having respective swivelling axes (B, C) and being rotationally linked to one another; the first and second swivelling levers (4,5) and their respective swivelling axes (B,C) being arranged symmetrically with respect to a plane (S) ;

- a counteraction swivelling lever (8) having a respective swivelling axis (E) , being rotationally linked to the first and second swivelling levers (4,5) and arranged in such a way that it extends along a direction intersecting said plane (S) ;

characterised in that

said swivelling axes (B, C, E) all lie on the circumference of a circle (10) , said plane (S) defining at its intersection with a plane orthogonal to said swivelling axes (B, C, E) a first diameter (Dl) of said circle (10) , and that said counteraction swivelling lever (8) and at least one of said first and second swivelling levers (5) and their respective swivelling axes (C,E) are arranged symmetrically with respect to a second diameter (D2) of said circle (10) .

2) The gripping device according to Claim 1, comprising a second counteraction swivelling lever (11) rotationally linked to the first and second swivelling levers (4,5) and to the first counteraction swivelling lever (8); having a respective swivelling axis (F) lying on the circumference of said circle (10) and being arranged in such a way that it extends along a direction intersecting said plane (S) ; said second counteraction swivelling lever (11) and the other one of said first and second swivelling levers (4) and their respective swivelling axes (B,F) being arranged symmetrically with respect to a third diameter (D3) of said circle (10) .

3) The gripping device according to Claim 1 or 2 , comprising at least a further swivelling lever rotationally linked to the first and second swivelling levers (4,5) and to the first and second counteraction swivelling lever (8, 11); having a respective swivelling axis lying on the circumference of said circle (10) and being arranged symmetrically to at least one of said swivelling levers (4,5,8,11) with respect to a further diameter of said circle (10) . 4) The gripping device according to any one of Claims 1 to 3 , comprising a base plate 14 to which said swivelling levers (4, 5, 8, 11) are pivotably linked. 5) The gripping device according to any one of

Claims 1 to 4 , wherein said swivelling levers (4,5, 8,

11) are rotationally linked to one another by means of gearwheel segments (6,7,9,12). 6) The gripping device according to any one of the

Claims 1 to 5, comprising an elastic means (15) operatively coupled with the first and second swivelling levers (4, 5) at respective end portions thereof and such that, when the elastic means (15) is in a respective non- stressed condition, the gripping device (1, 1') is held in its closed configuration.

7) The gripping device according to any one of the Claims 1 to 6, wherein one of said first and second swivelling levers (4, 5) comprises a projecting portion (40) extending on the side opposite a container contacting portion (41) of the swivelling lever (4,5), the projecting portion (40) bearing at its end portion (42) , rotationally coupled therewith, a cam-follower roller (43) .