Transfer star-wheel for containers of thermoplastic material

Abstract

Transfer star-wheel (1) for containers (100) of thermoplastic material, comprising: a rotary carousel (2) bearing a plurality of supporting stations (S) for supporting containers (100) by their neck (100b), in each supporting station (S) being provided a pliers (3) hinged to the rotary carousel (2) at a hinge axis (AA) in such a way that it assumes at least a first configuration in which the pliers (3) is fixed, that means it cannot rotate about its hinge axis (AA), and a second configuration in which the pliers (3) can oscillate about its hinge axis (AA); a cam kinematic motion that is operatively active on each pliers (3) for maintaining it in the first configuration,
characterized in that it comprises a reactivating device (8) for each pliers (3), that comprises elastic means (9, 10) operatively active on the pliers (3) to bring it from the second to the first configuration following an accidental event that deactivated the pliers.

Claims

1. Transfer star-wheel for containers of thermoplastic material, comprising: a rotary carousel bearing a plurality of supporting stations for supporting the containers by their neck, each supporting station being provided with pliers hinged to the rotary carousel at a hinge axis so that the pliers assumes at least a first configuration in which the pliers is fixed, that means it cannot rotate about the hinge axis, and a second configuration in which the pliers can oscillate about the hinge axis, each pliers comprising two jaws and a plate to which said jaws are integrally fixed, said plate being hinged to the rotary carousel at said hinge axis; a cam kinematic motion that is operatively active on each pliers for maintaining the pliers in the first configuration, wherein said cam kinematic motion comprises a roller coupled to a perimeter recess of said plate whereby said roller can slide on said perimeter recess; a reactivating device for each pliers, that comprises elastic means operatively active on the pliers to bring the pliers from the second to the first configuration following an accidental event that deactivated the pliers, wherein said perimeter recess is a curvilinear recess obtained on the edge of said plate.

2. The transfer star-wheel according to claim 1, wherein said plate is provided with a pin, said reactivating device comprising a further pin and an articulated arm that connects the further pin to the cam kinematic motion, said elastic means comprising a first spring interposed between said pin and said further pin to elastically couple said pin and further pin to a second spring in a preloaded position on the articulated arm.

3. The transfer star-wheel according to claim 2, wherein each supporting station comprises a further plate fixed to the rotary carousel, said plate, said cam kinematic motion and said reactivating device being fixed to said further plate.

4. The transfer star-wheel according to claim 2, wherein said further plate is fixed to a lower surface of the rotary carousel.

5. The transfer star-wheel according to claim 2, wherein said plate is provided with a pin that is slidably arranged in a corresponding arched opening obtained in said rotary carousel.

6. The transfer star-wheel according to claim 5, wherein said arched opening is a through-hole or a blind hole.

7. The transfer star-wheel according to claim 5, wherein part of said reactivating device extends above the rotary carousel and part of said reactivating device extends below said rotary carousel.

8. The transfer star-wheel according to claim 2, wherein said reactivating device is interposed between said pin and said cam kinematic motion.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) Further characteristics and advantages of the present invention will become more apparent from the following indicative and therefore non-limiting description of a transfer star-wheel for containers of thermoplastic material, as illustrated in the appended drawings in which:

(2) FIG. 1 shows a transfer star-wheel for containers of thermoplastic material, according to the present invention, seen from above;

(3) FIGS. 2a, 2b and 2c show a first embodiment of a supporting station of the transfer star-wheel of FIG. 1, respectively in bottom view, side view and sectional side view;

(4) FIG. 3 shows the supporting station of FIGS. 2a-2c, in perspective view from below;

(5) FIG. 4 shows a second embodiment of the supporting station of FIG. 3;

(6) FIGS. 5-6 show the supporting station of FIG. 4 mounted on the rotary carousel of the transfer star-wheel, respectively seen from below and from above;

(7) FIGS. 7a and 7b show, respectively, the first and second embodiment of the supporting station, in sectional side view.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

(8) With reference to the figures, the number 1 indicates a transfer star-wheel for containers 100 of thermoplastic material, for example PET.

(9) In particular, in this context the term “container” can be considered a preform of thermoplastic material or a formed container, which has a tubular body 100a and a threaded neck 100b.

(10) For example, the transfer star-wheel 1 is interposed between a forming unit 200 and a sterilizing unit 300 of the containers 100.

(11) The transfer star-wheel 1 comprises a rotary carousel 2 bearing a plurality of supporting stations S for supporting the containers 100 by their neck 100b.

(12) In each supporting station S a pliers 3 is provided, which is hinged to the rotary carousel 2 at a hinge axis AA so as to assume at least: a first configuration in which the pliers 3 is fixed, that means it cannot rotate about its hinge axis AA, and a second configuration in which the pliers 3 can oscillate about its hinge axis AA, that means the pliers 3 is neutral with respect to said hinge axis AA.

(13) Thus, each pliers 3 is rotatably hinged to the rotary carousel 2 at its hinge axis AA.

(14) As can be seen from the figures, each pliers 3 comprises two jaws 3a, 3b elastically coupled, and a plate 4 to which the jaws 3a, 3b are integrally fixed. In particular, the plate 4 is hinged to the rotary carousel 2 at the hinge axis AA. Each pliers 3 is maintained in the first configuration by a cam kinematic motion. Preferably, the cam kinematic motion comprises a roller 7 coupled to a perimeter recess 4a of the plate 4 in such a way that the roller 7 can slide in the perimeter recess 4a.

(15) In particular, the plate 4 of each pliers 3 has a substantially disc-like shape and the perimeter recess 4a is a curvilinear recess obtained on the outer perimeter area of the plate 4.

(16) When a jamming occurs downstream of the transfer star-wheel 1, or more in general a slowdown, the pliers 3 is uncoupled, that means it passes from the first configuration in which it is fixed to the second configuration in which it can oscillate with respect to the hinge axis AA. In particular, following the jamming, the plate 4 begins to rotate about the hinge axis AA so that its perimeter recess 4a slides on the roller 7.

(17) Advantageously, for each pliers 3 a reactivating device 8 is present which comprises elastic means 9, 10 operatively active on the pliers 3 to bring it from the second to the first configuration. The reactivating device 8 then intervenes following the removal of the jamming downstream of the transfer star-wheel 1 or following the resumption of the advancement of the containers 100.

(18) In accordance with a first embodiment illustrated in FIGS. 2a-2c, 3 and 7a, the plate 4 is provided with a pin 5 and the reactivating device 8 comprises a further pin 11, integrally fixed to the rotary carousel 2.

(19) The reactivating device 8 comprises elastic means 9, 10 consisting of: a first spring 9 interposed between the pin 5 and the further pin 11 in such a way as to elastically couple them; a second spring 10 in preloaded position on an articulated arm 12 which connects the further pin 11 to the cam kinematic motion.

(20) In particular, the reactivating device 8 is interposed between the pin 5 of the plate 4 and the cam kinematic motion.

(21) In accordance with a second embodiment illustrated in FIGS. 4, 5, 6 and 7b, the plate 4 is provided with a pin 5 that is slidably engaged in an arched opening 6 obtained in the rotary carousel 2.

(22) As many arched openings 6 are obtained in the rotary carousel 2 as there are supporting stations S (and therefore pins 5).

(23) Preferably, each arched opening 6 is a through-hole. Alternatively, the arched opening 6 can be a blind hole.

(24) When a jamming occurs downstream of the transfer star-wheel 1, or more in general a slowdown, the pliers 3 is uncoupled, that means it passes from the first configuration in which it is fixed to the second configuration in which it can oscillate with respect to the hinge axis AA. In particular, following the jamming, the plate 4 begins to rotate about the hinge axis AA so that its perimeter recess 4a slides on the roller 7.

(25) The pin 5 of the plate 4, in turn, slides into the corresponding arched opening 6 of the rotary carousel 2.

(26) FIGS. 7a-7b show the differences between the first and the second embodiment. In particular: in the first embodiment illustrated in FIG. 7a, the supporting station S comprises a further plate 14 having one side fixed to the rotary carousel 2 and the other bearing the plate 4 with the pliers 3, the cam kinematic motion and the reactivating device 8; in the second embodiment illustrated in FIG. 7b, the pin 5 of the plate 4 crosses the rotary carousel 2 at the arched opening 6. In this way, part of the reactivating device 8 extend below the rotary carousel 2 and part of the reactivating device 8 extend above the rotary carousel 2.

(27) Preferably, in the first embodiment, the further plate 14 is fixed to a lower surface 2a of the rotary carousel 2.

(28) The first embodiment is more compact than the second embodiment and structurally simpler because all the elements of the supporting station S are located on one side (underneath) of the rotary carousel 2.

(29) In the second embodiment, however, some components of the reactivating device 8 extend above the rotary carousel 2 and other components extend below the rotary carousel 2.

(30) From the description given, the features of the transfer star-wheel for containers of thermoplastic material according to the present invention appear clear, as do the advantages thereof.

(31) In particular, when jamming or slowdowns occur, the pliers can uncouple from its fixed position, and then be automatically returned to such a position when the cause of the jamming/slowdown has been eliminated. This is ensured by the reactivating device proposed herein.