Apparatus for processing preforms

Abstract

An apparatus (1) for processing plastic preforms, comprising a line (10) for feeding preforms (50), which comprise a preform body (51) and a preform mouth (52), the feed line (10) being arranged upstream of an oven (2) for conditioning the preforms (50), an assembly (20) being provided for unloading the preforms (50) and being arranged downstream of the conditioning oven (2) and designed to feed the preforms (50) to a transfer or blow molding carousel, the conditioning oven (2) being associated with a closed conveyance circuit (3) comprising a plurality of supporting elements (4) configured to support respective preforms (50), the feed line (10) having a feeding device (11) designed to feed the preforms (50) to the closed conveyance circuit (3), and the unloading assembly (20) having an unloading device (21) designed to take the preforms (50) from the closed conveyance circuit (3), characterized in that it comprises a control and actuation device configured to actuate the transition of the apparatus (1) between an operating condition in which the preforms (50) are fed, via the feed line (10), to the closed conveyance circuit (3) and are sent, via the unloading assembly (20), to the transfer or blow molding carousel, and a recirculation condition, in which the feeding of the preforms (50) to the closed conveyance circuit (30) via the feed line (10) is interrupted and in which the unloading assembly (20) is not functionally connected to the closed conveyance circuit (30), in the recirculation condition the preforms (50) supported by the respective supporting elements (4) being moved along the closed conveyance circuit (3) and the preforms (50) supported by the respective supporting elements (4) not taken by the unloading assembly (20) being sent again toward the conditioning oven (2).

Description

[0001] APPARATUS FOR PROCESSING PREFORMS

[0002] The present invention relates to an apparatus for processing preforms.

[0003] Plants for blow molding plastic containers are known that comprise an apparatus for blow molding preforms so as to obtain containers such as bottles, for example.

[0004] The preforms are fed to the preform blow molding apparatus by means of a conveyor associated with a preform thermal conditioning oven.

[0005] The conveyor is normally associated with a preform transfer device, constituted for example by a handling device, which takes the preforms from the conveyor to transfer them to the preform blowing apparatuses.

[0006] The conveyor is also associated in input with an additional transfer device, designed to take the preforms from a feed line to transfer them to the conveyor.

[0007] The transfer device is also normally constituted by a handling device provided with grippers for picking up the preforms.

[0008] Known solutions, while widely used, are not without drawbacks, however.

[0009] In particular, the apparatus may be subject to a series of problems that affect its devices arranged both upstream and downstream of the conveyor, in which case it is necessary in many cases to stop the apparatus until the problem is resolved.

[0010] Such operations, if they continue beyond a certain amount of time, then force the rejection of the preforms arranged along the conveyor due to the excessive thermal stresses that they have undergone.

[0011] Upon restarting the plant, it is therefore necessary to unload the preforms and only then to start feeding again.

[0012] The aim of the present invention is to provide an apparatus for processing preforms that is capable of avoiding the drawbacks of the background art in one or more of the aspects mentioned above. Within this aim, an object of the invention is to provide an apparatus for processing preforms that allows to significantly increase productivity while reducing waste in case of apparatus downtime.

[0013] Not least object of the invention is to provide a preform processing apparatus that is highly reliable, relatively easy to provide, and at competitive costs.

[0014] This aim, as well as these and other objects that will become better apparent hereinafter, are achieved by a preform processing apparatus according to claim 1, optionally provided with one or more of the characteristics of the dependent claims.

[0015] Further characteristics and advantages of the invention will become better apparent from the description of some preferred but not exclusive embodiments of the apparatus for processing preforms according to the invention, illustrated by way of non-limiting example in the accompanying drawings, wherein:

[0016] Figure 1 is a schematic top view of the apparatus according to the invention in the operating condition;

[0017] Figure 2 is a view, similar to the preceding one, with the apparatus in the condition of transition between the operating and recirculating conditions;

[0018] Figure 3 is a view, similar to the preceding ones, with the apparatus in the recirculation condition;

[0019] Figure 4 is a view, similar to the preceding ones, with the apparatus in the condition of transition between the recirculation condition and the operating condition;

[0020] Figures 5 and 6 are perspective views of the feeding region with the apparatus in the operating and recirculating condition, respectively.

[0021] The preform processing apparatus, generally designated by the reference numeral 1, comprises a line 10 for feeding preforms 50 (plastic preforms), which comprise a preform body 51 and a preform mouth 52. The feed line 10 is arranged upstream of an oven 2 for conditioning the preforms 50.

[0022] The apparatus comprises an assembly 20 for unloading the preforms 50, which is arranged downstream of the conditioning oven 2 and is designed to feed the preforms 50 to a transfer or blow molding carousel (not shown in the figures).

[0023] The conditioning oven 2 is associated with a closed conveyance circuit 3, which comprises a plurality of supporting elements 4 configured to support respective preforms 50.

[0024] The feed line 10 is provided with a feeding device 11, which is designed to feed the preforms 50 to the closed conveyance circuit 3, while the unloading assembly 20 is provided with an unloading device 21 designed to take the preforms 50 from the closed conveyance circuit 3.

[0025] According to the present invention, the apparatus 1 comprises an actuation and control device, not shown in the figures, which is configured to actuate the transition of the apparatus 1 between an operating condition, in which the preforms 50 are fed, via the feed line 10, to the closed conveyance circuit 3 and are sent, via the unloading assembly 20, to the transfer or blow molding carousel, and a recirculation condition, in which the feeding of the preforms 50 to the closed conveyance circuit 30 via the feed line 10 is interrupted and in which the unloading assembly 20 is not functionally connected to the closed conveyance circuit 30.

[0026] In particular, in the recirculation condition the preforms 50 supported by the respective supporting elements 4 are moved along the closed conveyance circuit 3 and the preforms 50 supported by the respective supporting elements 4 not taken by the unloading assembly 20 are sent back to the conditioning oven 2.

[0027] Advantageously, as shown in the figures, the closed conveyance circuit 3 comprises a plurality of supporting elements 4 which can move, along a respective movement path 102 between a feeding region 200 formed at the feed line 10 upstream of the conditioning oven 2, and a release region 300 arranged at the unloading assembly 20, arranged downstream of the conditioning oven 2.

[0028] Conveniently, the control and actuation means are functionally connected to means for controlling the speed of travel of the preforms 50 along the closed conveyance circuit 3 with the apparatus 1 in the recirculation condition.

[0029] Moreover, the control and actuation means are functionally connected to means for controlling the temperature of the conditioning oven 2 with the apparatus 1 in the recirculation condition.

[0030] Advantageously, the feeding device 11 comprises a feeding star conveyor I la associated with a feeding guide 201.

[0031] The feeding guide 201 is configured to guide the preforms that travel along the feed line 10 to engage with a respective supporting element 4.

[0032] The feeding guide 201 is, in particular, movable on command to switch between an active condition, with the apparatus 1 in the operating condition, and an inactive condition, with the apparatus 1 in the recirculation condition.

[0033] The feeding guide 201, in the active condition, has at least one portion that affects the closed conveyance circuit 2 for feeding the preforms 50 to the closed conveyance circuit 3, while in the inactive condition the feeding guide 201 is moved away from the closed conveyance circuit 3 to allow the preforms 50 to transit along the closed conveyance circuit 3 at the feeding region 200.

[0034] With reference to the embodiment shown in the figures, the supporting body 4 is configured to form a support for the rim of the mouth of the preform 52.

[0035] In this regard, the upper portion of the supporting body 4 is arranged at a lower elevation than the elevation at which the mouth of the preform 52 lies at the feeding region 200. The feeding device 11 comprises, for example, a feeding star conveyor, which forms, at the peripheral region, a plurality of receptacles for a respective preform 50.

[0036] The preforms 50 are conveyed to the feeding device 11 with the mouth of the preform 52 directed downward.

[0037] The receptacles I la comprise a respective recessed region in which the concavity is directed downward and which is intended to accommodate, at least partially, a respective preform 50 with its mouth 52 directed downward.

[0038] According to a preferred embodiment, the supporting elements 4 are supported by a chain that extends along the closed conveyance circuit 3.

[0039] The chain comprises a plurality of pins interconnected by respective links: the supporting elements comprise respective bodies, i.e., supporting spindles arranged coaxially to respective pins of the chain.

[0040] The supporting spindles are associated with movement means adapted to allow their rotation about their own axis, at least while passing through the conditioning oven 2.

[0041] The preforms 50 are, in particular, of the type having a preform body 51 that has a smaller transverse dimension than the preform mouth 52.

[0042] The preforms 50 may have, of course, a greater extension in height than their diameter.

[0043] Advantageously, the preforms 50 have a conical or frustum-like extension.

[0044] The operation of the apparatus 1, according to the invention, is as follows.

[0045] The preforms 50 are fed via the feed line 10 to the closed conveyance circuit 3 at the feeding region 200.

[0046] From the feed line 10, the preforms 50 are fed onto a respective supporting body 4 which can move along the conveyance circuit 3 so as to make the respective preform 50 pass through the conditioning oven 2. Upon exiting the oven 2, the supporting bodies 4 bring the preforms 50, for example supported in such a way that the mouth 52 is directed downward, toward the pick-up region 300, at the unloading assembly 20, which comprises, for example, a tipping device which proceeds to pick them up from the respective supporting body 4 to bring them to a pick-up condition with the respective mouth 52 directed upward.

[0047] At this point, the pick-up device, constituted for example by an articulated arm provided with grip means at the free end, picks up the preform 50 from the tipping element to feed it to the blow molding carousel.

[0048] If problems arise during use, for example at the blow molding machine or at the feeder, the control and actuation device acts on the apparatus 1 to move it from the operating condition to the recirculation condition.

[0049] In practice, the feeding device and the unloading assembly are substantially stopped and the feeding guide 201 is moved from the active condition to the inactive condition so that the preforms 50 already supported by the closed conveyance circuit 3 continue circulation by passing even multiple times through the conditioning oven 2 once the unloading region 300 has been passed.

[0050] In this step, the control and actuation device can also act on the speed of travel of the preforms 50 along the closed conveyance circuit 3, and optionally also on the temperature of the conditioning oven so as not to compromise the preforms during recirculation.

[0051] Moving the feeding guide 201 from the active position to the inactive position allows the preforms that arrive from the unloading region 300 to pass through the feeding region 200 again to return to the conditioning oven 2.

[0052] Once the problem is resolved, the feeding device is reactivated.

[0053] In practice it has been found that the invention achieves the intended aim and objects, providing an apparatus for blow molding containers that allows to feed preforms of different diameters and shapes, moreover without having to engage on the outer surface of the preform.

[0054] The invention thus conceived is susceptible of numerous modifications and variations, all of which are within the scope of the appended claims; all the details may furthermore be replaced with other technically equivalent elements.

[0055] In practice, the materials used, so long as they are compatible with the specific use, as well as the contingent shapes and dimensions, may be any according to the requirements and the state of the art. The disclosures in Italian Patent Application No. 102023000026391 from which this application claims priority are incorporated herein by reference.

[0056] Where technical features mentioned in any claim are followed by reference signs, those reference signs have been included for the sole purpose of increasing the intelligibility of the claims and accordingly such reference signs do not have any limiting effect on the interpretation of each element identified by way of example by such reference signs.

Claims

CLAIMS1. An apparatus (1) for processing plastic preforms, comprising a line (10) for feeding preforms (50), which comprise a preform body (51) and a preform mouth (52), said feed line (10) being arranged upstream of an oven (2) for conditioning said preforms (50), an assembly (20) being provided for unloading said preforms (50) and being arranged downstream of said conditioning oven (2) and designed to feed said preforms (50) to a transfer or blow molding carousel, said conditioning oven (2) being associated with a closed conveyance circuit (3) comprising a plurality of supporting elements (4) configured to support respective preforms (50), said feed line (10) having a feeding device (11) designed to feed said preforms (50) to said closed conveyance circuit (3), and said unloading assembly (20) having an unloading device (21) designed to take said preforms (50) from said closed conveyance circuit (3), characterized in that it comprises a control and actuation device configured to actuate the transition of said apparatus (1) between an operating condition in which said preforms (50) are fed, via said feed line (10), to said closed conveyance circuit (3) and are sent, via said unloading assembly (20), to said transfer or blow molding carousel, and a recirculation condition, in which the feeding of the preforms (50) to said closed conveyance circuit (30) via said feed line (10) is interrupted and in which the unloading assembly (20) is not functionally connected to said closed conveyance circuit (30), in said recirculation condition the preforms (50) supported by the respective supporting elements (4) being moved along said closed conveyance circuit (3) and the preforms (50) supported by the respective supporting elements (4) not taken by said unloading assembly (20) being sent again toward said conditioning oven (2).

2. The apparatus (1) according to claim 1, characterized in that said closed conveyance circuit (3) comprises a plurality of supporting elements (4) which can move along a respective movement path (102) between a feeding region (200) formed at said feed line (10) upstream of saidconditioning oven (2), and a release region (300) located at said unloading assembly (20) downstream of said conditioning oven (2).

3. The apparatus (1) according to claim 1, characterized in that said control and actuation means are functionally connected to means for controlling the speed of travel of said preforms (50) along said closed conveyance circuit (3) with said apparatus (1) in the recirculation condition.

4. The apparatus (1) according to claim 1, characterized in that said control and actuation means are functionally connected to means for controlling the temperature of said conditioning oven (2) with said apparatus (1) in the recirculation condition.

5. The apparatus (1) according to claim 1, characterized in that said feeding device (11) comprises a feeding star conveyor (I la) associated with a feeding guide (201) configured to guide the preforms that travel through said feed line (10) to engage a respective supporting element (4), said feeding guide (201) being movable on command to transition between an active condition with said apparatus (1) in an operating condition and an inactive condition with said apparatus (1) in a recirculating condition, said feeding guide (201) in said active condition having at least one portion that affects said closed conveyance circuit (3) to feed the preforms (50) to said closed conveyance circuit (3), in said inactive condition said feeding guide (201) being moved away from said closed conveyance circuit (3) to allow said preforms (50) to transit along said closed conveyance circuit (3) at said feeding region (200).

6. The apparatus (1) according to claim 1, characterized in that said supporting element (4) comprises a supporting body (4a) configured to form a support for a rim of the preform mouth (52).

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