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Dokumentenidentifikation EP1445090 24.05.2007
EP-Veröffentlichungsnummer 0001445090
Titel Transportsternrad mit veränderbarem Achsabstand zwischen den Gegenständen für eine Rotationsblasformmaschine
Anmelder SMI S.p.A., San Giovanni Bianco, Bergamo, IT
Erfinder Nava, Paolo, 24015 San Giovanni Bianco (BG), IT
Vertreter derzeit kein Vertreter bestellt
DE-Aktenzeichen 60313117
Vertragsstaaten AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GB, GR, HU, IE, IT, LI, LU, MC, NL, PT, RO, SE, SI, SK, TR
Sprache des Dokument EN
EP-Anmeldetag 23.12.2003
EP-Aktenzeichen 030295919
EP-Offenlegungsdatum 11.08.2004
EP date of grant 11.04.2007
Veröffentlichungstag im Patentblatt 24.05.2007
IPC-Hauptklasse B29C 49/42(2006.01)A, F, I, 20051017, B, H, EP

Beschreibung[en]

The present invention relates to a variable-pitch arm star construction for rotary molding machines for making, by drawing and blowing, plastic vessels and bottles, and a rotary molding machine comprising the star construction.

More specifically, the field of the invention is that of the machines which are used for making plastic material bottles and vessels, particularly of PET, by a drawing-blowing molding process, carried out starting from a molded preform.

For making the above mentioned bottles or vessels, a starting preform or parison, consisting of a tubular PET body having a closed bottom, is heated to a desired molding temperature, drawn, pre-blown and blown to a final forming pressure, for forming the bottle inside the mold.

In the above mentioned types of molding machines, the molds are rotatably supported on a supporting star or wheel construction, upstream and downstream of which are provided star arrangements, respectively for supplying the parisons and removing the blown bottles.

In particular, the star construction designed for feeding the parisons to the mold must be adapted to receive the parisons from a rotary feeder having a small operating pitch, and to transfer the received parison toward the mold supporting wheel, which has a larger pitch.

Variable pitch arm star construction are also known: however, they are greatly complex, and their variable pitch can be replaced or re-timed only by performing very difficult operations.

The document FR-2 802 191 substantially discloses the preamble of Claim 1.

SUMMARY OF THE INVENTION

Accordingly, the main object of the present invention is to overcome the above mentioned drawbacks of the prior art, by providing a variable pitch arm star construction which allows to quickly and simply replace the cams thereof, depending on the preselected operating pitch.

The above and yet other objects, which will become more apparent hereinafter, are achieved by the star construction according to claim 1.

Preferred embodiments of the invention are disclosed in the remaining claims.

With respect to a conventional prior star construction, the variable pitch arm star assembly according to the present invention allows to perform, in a very quick and simple manner, all of the operations which are necessary for modifying the pitch of the star arms.

BRIEF DESCRIPTION OF THE DRAWINGS

The above mentioned, as well as yet other characteristics and advantages of the invention, will become more apparent from the accompanying drawings, in which is shown, by way of an example and not of limitation, a preferred embodiment of the inventive variable pitch arm star construction.

In the drawings:

  • Figure 1 is a top plan view illustrating an operating assembly for feeding the parisons and removing the blown bottles, said operating assembly including two variable pitch star constructions according to the invention;
  • Figure 2 illustrates the operating assembly shown in figure 1, the star construction being respectively shown in a side view and in a cross-sectional view;
  • Figure 3 illustrates, by a top plan view, the gripper assembly of the star construction of the preceding figures;
  • Figures 4 and 6 illustrate the gripper assembly of figure 3, respectively by a cross-sectional view B-B, a cross-sectional view A-A and a front view;
  • Figures 7 to 10 respectively illustrates the operating steps for starting the parison taking operation, removing the parisons from their supply, introducing said parisons into the mold, and releasing said parison in said mold.

DESCRIPTION OF THE PREFERRED EMBODIMENT

The operating assembly shown in figures 1 and 2 comprises a supplying star construction 1 for feeding or supplying the parisons 2 to the mold 3, supported by a respective star construction 4, and a further star construction 5 for taking or removing the bottles 6 from the mold 3.

Said star constructions 1 and 5 are in turn provided with a plurality of variable pitch arms 7, each having gripper elements 8.

More specifically, the variable pitch arm 7 shown in figures 3 to 6, comprises two levers, respectively indicated by 9 and 10, designed for cooperating with respective contours of cams 11 and 12 at their end portions 17 and 18 (see figures 2, 7, 8).

Said levers 9 and 10 are in turn mutually pivoted at a pivot pin 13 supported by a supporting flange 14.

The lever 10 has a substantially L-shape construction, with an end portion 15 articulated on the gripper 8 at a double pin element 16.

The lever 9, which also has a substantially L-shape, has an end portion 19 thereof pivoted on a connecting rod 20, in turn articulated on the double pin element 16.

As is clearly shown in figures 4 and 6, the end portions 17 and 18 of the levers 9 and 10 are provided with a different diameter double-bearing, respectively indicated by the reference numbers 21 and 22.

Said bearings are designed for engaging in a corresponding engaging slot, defining the above mentioned cam contours 11 and 12.

As shown in figure 6, the larger diameter bottom portion 23 of the double bearing 22 (or 21) interferes against the inner edge 24 of the cam contour, whereas the smaller diameter top portion 25 of that same bearing bears on the outer edge 26 of said cam contour.

Thus, it is assured a proper rolling ratio between the end portions of the levers and the respective cam contours, thereby advantageously eliminating any clearances.

The mode of operation of the variable pitch arm star construction according to the invention is shown in figures 7 to 10, in which have been shown the different operating positions assumed by an arm and related gripper, respectively as the arm is moved toward the parison, as it removes the latter, and is moved toward the respective mold to release the parison in said mold.

Owing to the very simple construction of the variable pitch arms 7, the latter can be easily and simply removed from their supporting star construction, for their replacement or for adjusting them, by merely removing the respective supporting flange 14 from the star construction body (for example by removing screws or other fixing elements).


Anspruch[de]
Transportsternrad (1) mit veränderbarem Achsabstand zwischen den Gegenständen für eine Rotationsblasformmaschine zum Herstellen von Kunststoffbehältern oder - flaschen durch einen Tiehzieh-Blasvorgang, wobei das Transportsternrad Arme (7) mit Greifelementen (8) und ein zusammenwirkendes Hebel- und Nockensystem (9, 10, 11, 12) zum Ändern des Achsabstandes der Arme (7) und zum ordnungsgemäßen Ausrichten der Greifelemente (8) umfasst, wobei das System zwei Hebel (9, 10) umfasst, die auf einer Seite das Greifelement (8) in Eingriff nehmen und auf der anderen Seite mit den Konturen zweier Nocken (11, 12) zusammenwirken, und dadurch gekennzeichnet, dass die Hebel (9, 10) jeweilige Endabschnitte aufweisen, die jeweils ein Doppellager (21, 22) mit unterschiedlichem Durchmesser aufweisen, das die Nockenkonturen (11, 12) in Eingriff nimmt. Transportsternrad nach Anspruch 1, dadurch gekennzeichnet, dass die Hebel (9, 10) an einem Schwenkzapfen (13) angelenkt sind, der durch einen jeweiligen Stützflansch (14) gestützt wird, wobei der Stützflansch (14) starr mit dem Transportsternrad (1) ausgebildet ist. Transportsternrad nach Anspruch 1, dadurch gekennzeichnet, dass die Hebel (9, 10) im Wesentlichen eine L-Form haben, wobei ein Endabschnitt (15) eines Hebels (10) an dem Greifelement (8) an einem Schwenkzapfen (16) angelenkt ist, wobei ein Endabschnitt (19) des anderen Hebels (9) an einer Verbindungsstange (20) angelenkt ist, die wiederum an dem Schwenkzapfen (16) angelenkt ist. Transportsternrad nach Anspruch 3, dadurch gekennzeichnet, dass der Schwenkzapfen (16) ein doppelter Schwenkzapfen ist. Transportsternrad nach Anspruch 1, dadurch gekennzeichnet, dass das Doppellager (21, 22) einen unteren Abschnitt (23) aufweist, der gegen eine Innenkante (24) der Nockenkontur (11, 12) stößt, und einen oberen Abschnitt (25) aufweist, der an einer Außenkante (26) der Nockenkontur anliegt. Transportsternrad nach Anspruch 5, dadurch gekennzeichnet, dass der untere Abschnitt (23) des Doppellagers (21, 22) einen Durchmesser aufweist, der größer ist als der Durchmesser des oberen Abschnitts (25) des Doppellagers (21, 22). Rotationsblasformmaschine zum Herstellen von Kunststoffbehältern oder -flaschen durch einen Tiehzieh-Blasvorgang, dadurch gekennzeichnet, dass die Maschine wenigstens ein Transportsternrad (1) mit veränderbarem Achsabstand zwischen den Gegenständen nach einem oder mehreren der vorangehenden Ansprüche umfasst.
Anspruch[en]
A variable pitch arm star construction (1) for rotary molding machine for making plastic vessels or bottles by a drawing-blowing operation, whereby said star construction comprises arms (7) having gripper elements (8) and a cooperating lever and cam system (9, 10, 11, 12) for changing the pitch of said arms (7) and for properly orienting said gripper elements (8), wherein said system comprises two levers (9, 10) which, on a side, engages with said gripper element (8) and, on the other side, cooperate with the contours of two cams (11, 12), and characterized in that said levers (9, 10) have respective end portions including each a different diameter double bearing (21, 22) engaging the cam contours (11, 12). A star construction according to Claim 1, characterized in that said levers (9, 10) are pivoted on a pivot pin (13) supported by a respective supporting flange (14), said supporting flange (14) being rigid with said star construction (1). A star construction according to Claim 1, characterized in that said levers (9, 10) have a substantially L-shape, one end portion (15) of a said lever (10) being pivoted on said gripper element (8) on a pivot pin (16), an end portion (19) of the other lever (9) being pivoted on a connecting rod (20) in turn articulated on said pivot pin (16). A star construction according to Claim 3, characterized in that said pivot pin (16) is a double pivot pin. A star construction according to Claim 1, characterized in that said double bearing (21, 22) has a bottom portion (23) interfering against an inner edge (24) of said cam contour (11, 12), and a top portion (25) bearing on an outer edge (26) of said cam contour. A star construction according to Claim 5, characterized in that said bottom portion (23) of said double bearing (21, 22) has a diameter larger than that of said top portion (25) of said double bearing (21, 22). A rotary molding machine for making plastic vessels or bottles by a drawing-blowing operation, characterized in that said machine comprises at least a variable pitch arm star construction (1) according to one or more of the preceding claims.
Anspruch[fr]
Construction étoilée avec des bras à pas variable (1), destinée à une machine de moulage rotative permettant de fabriquer des récipients ou des bouteilles en plastique grâce à une opération de soufflage-étirage, moyennant quoi ladite construction étoilée comprend des bras (7) ayant des éléments de préhension (8) et un levier coopérant et un système de cames (9, 10, 11, 12) permettant de modifier le pas desdits bras (7) et d'orienter de manière appropriée lesdits éléments de préhension (8), dans laquelle ledit système comprend deux leviers (9, 10) qui, d'un côté, s'engagent avec ledit élément de préhension (8) et, de l'autre côté, coopèrent avec les contours des deux cames (11, 12), et caractérisée en ce que lesdits leviers (9, 10) ont des sections d'extrémité respectives incluant chacune un palier double (21, 22) ayant des diamètres différents, lequel s'engage avec les contours des cames (11, 12). Construction étoilée selon la revendication 1, caractérisée en ce que lesdits leviers (9, 10) sont pivotés sur un axe de pivotement (13) soutenu par un flasque d'appui (14) respectif, ledit flasque d'appui (14) étant installé fermement par rapport à ladite construction étoilée (1). Construction étoilée selon la revendication 1, caractérisée en ce que lesdits leviers (9, 10) ont sensiblement une forme de L, une section d'extrémité (15) d'un dit levier (10) étant amenée à pivoter sur ledit élément de préhension (8) sur un axe de pivotement (16), une section d'extrémité (19) de l'autre levier (9) étant amenée à pivoter sur une tige de raccordement (20) à son tour articulée sur ledit axe de pivotement (16). Construction étoilée selon la revendication 3, caractérisée en ce que ledit axe de pivotement (16) est un axe de pivotement double. Construction étoilée selon la revendication 1, caractérisée en ce que ledit double palier (21, 22) comporte une section inférieure (23) qui interfère contre un bord interne (24) dudit contour de came (11, 12), et une section supérieure (25) reposant sur un bord externe (26) dudit contour de came. Construction étoilée selon la revendication 5, caractérisée en ce que ladite section inférieure (23) dudit double palier (21, 22) a un diamètre supérieur à celui de ladite section supérieure (25) dudit double palier (21, 22). Machine de moulage rotative permettant de fabriquer des récipients ou des bouteilles en plastique grâce à une opération de soufflage-étirage, caractérisée en ce que ladite machine comprend au moins une construction étoilée avec des bras à pas variable (1) selon une ou plusieurs des revendications précédentes.






IPC
A Täglicher Lebensbedarf
B Arbeitsverfahren; Transportieren
C Chemie; Hüttenwesen
D Textilien; Papier
E Bauwesen; Erdbohren; Bergbau
F Maschinenbau; Beleuchtung; Heizung; Waffen; Sprengen
G Physik
H Elektrotechnik

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