Inverter unit for a machine for molding glass articles

Abstract: An inverter unit (1) for a machine for molding glass articles has a supporting frame (2), and two gripping members (13) connected to the frame (2) and rotated about a hinge axis (8) by a mechanical transmission (17, 23) powered by a rotary motor (28); the motor (28) having an output shaft (27) extending parallel to and at a distance from the hinge axis (8); and the transmission (17, 23) having at least one toothed belt (26).

Description: The present invention relates to an inverter unit for a machine for molding glass articles, and in particular for a so-called I.S. molding machine. As is known, I.S. machines comprise a number of molding sections, each of which in turn comprises a parison mold, a finish mold, and an inverter unit between the parison and finish molds. The inverter unit comprises a supporting frame connected to the machine structure; and a gripping member, which grips the parisons formed in the parison mold, and is connected to the frame to rotate about a horizontal axis and transfer the parisons to the finish mold. The gripping member is normally rotated about the horizontal axis by a drive assembly comprising a gear transmission in turn comprising a gear coaxial with the rotation axis and angularly integral with the gripping member. The gear meshes with a worm, which is connected to the frame to rotate about a vertical axis and is connected to the output shaft of a respective vertical-axis electric drive motor. Alternatively, the gear meshes with a vertical rack moved by a linear actuator as disclosed in US-A-3 617 233. Though widely used, known drive assemblies of the above type have the drawback of being extremely bulky in height and, above all, in a horizontal direction perpendicular to the rotation axis, and so occupying all the space between the relative molds. Moreover, using a worm-helical gear or rack-and-pinion assembly, the worm/rack must be disconnected from the frame and/or motor/actuator to replace or service the motor/actuator, thus resulting in losses in terms of downtime and cost, while normal maintenance of the unit is a long, painstaking job when it calls for releasing the gripping member from angular connection to the worm/rack. It is an object of the present invention to provide an inverter unit designed to provide a straightforward, low-cost solution to the above problems. According to the present invention, there is provided an inverter unit for a machine for molding glass articles, the unit comprising a supporting frame; gripping means connected to the frame to rotate about a horizontal hinge axis and transfer, in use, parisons from a parison mold to a finish mold; a motor for powering said gripping means and having an output shaft rotating about a respective axis; and a mechanical transmission interposed between said motor and said gripping means; characterized in that the axis of said output shaft extends at a distance from said hinge axis and lies in a substantially horizontal plane. A number of 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 view in perspective, with parts removed for clarity, of a first preferred embodiment of the inverter unit according to the present invention; Figure 2 shows a partly sectioned side view of the Figure 1 unit; Figure 3 shows a view in perspective, with parts removed for clarity, of a second preferred embodiment of the inverter unit according to the present invention; Figure 4 shows a partly sectioned side view of the Figure 2 unit. Number 1 in Figure 1 indicates as a whole an inverter unit for a so-called I.S. machine (not shown) for molding glass articles and comprising a parison mold (not shown) and a finish mold (not shown). Unit 1 provides for successively transferring one or more parisons (not shown) from the parison mold to the finish mold, and comprises a frame 2 in turn comprising an elongated bottom fastening plate 3 connected to a supporting structure of the machine (not shown), and two uprights 4 extending upwards from plate 3 and connected to each other by a platelike intermediate crosspiece 5 at a distance from plate 3. The free top ends of uprights 4 are fitted with a driven shaft 7, which rotates about a respective horizontal axis 8 and extends through two sleeves 9 extending adjacent to respective uprights 4 and connected in axially-sliding, angularly-fixed manner to shaft 7 by a known splined coupling 11 (Figure 1). Each sleeve 9 is fitted integrally - by means of a known releasable fastening device 12 not described in detail - with a respective known radial gripping member 13 - not described in detail - which, together with respective sleeve 9, is movable with respect to shaft 7 and in opposite directions along axis 8 by a respective known linear actuator interposed between shaft 7 and respective sleeve 9. A variable-volume chamber 14 of one of the linear actuators is shown in Figure 2. Sleeves 9 are separated by a gear 16 fitted to an intermediate portion of shaft 7 and forming part of a mechanical transmission 17 for rotating gripping members 13 between a gripping position to pick up the parisons from the parison mold, and a release position to deposit the parisons inside the finish mold. Transmission 17 also comprises a gear 18, which meshes with gear 16 and is fitted to an intermediate driven shaft 19 in turn fitted in axially-fixed manner to crosspiece 5 by means of two supports 21 so as to rotate about a respective axis 20 parallel to axis 8. Shaft 19 has an end portion projecting from one of supports 21 and fitted with a pulley 22 of a belt transmission 23, which also comprises a second pulley 24 rotating about an axis 25 parallel to axes 8 and 20, and a toothed belt 26 looped about pulleys 22 and 24. Pulley 24 is fitted to a drive shaft 27 coaxial with axis 25 and forming the output shaft of a rotary horizontal-axis motor reducer 28, which extends beneath plate 3 and is connected adjustably to a supporting portion 29 connected integrally to plate 3 and extending downwards on the opposite side of plate 3 to uprights 4. The Figure 3 and 4 embodiment relates to an inverting unit 30, which differs in certain design details from unit 1, and the component parts of which are indicated where possible using the same reference numbers as for the corresponding parts of unit 1. Unit 30 differs from unit 1 by gear 16 being replaced with a toothed pulley 32; by driven shaft 19, gear 18 and pulley 22 being dispensed with; and by belt 26 being replaced with a belt 33 looped about pulleys 24 and 32. Belt 33 has two branches 34, one of which extends over an idle transmission roller 35 located between bottom plate 3 and crosspiece 5 and connected to frame 2 to rotate about an axis 36 parallel to axes 8 and 25. As will be clear from the above, locating motor reducer 28 beneath bottom plate 3, and with its axis 25 parallel to the hinge axis 8 of gripping members 13, provides, unlike known solutions, for greatly reducing the transverse dimensions of units 1 and 30, and in particular in a direction perpendicular to axes 8 and 25. By connecting motor reducer 28 directly to and entirely beneath frame 2, the whole of unit 1; 30 can be taken out and put back in one operation - since all the component parts of the unit are carried by the frame, and only bottom plate 3 needs connecting to the machine structure - and extremely easily, by both the motor and transmission being protected and so prevented from latching on to or knocking against other parts of the machine. Moreover, using a toothed-belt transmission provides for releasing the shaft, and hence the gripping members, quickly and easily from angular connection to the motor reducer by simply removing the toothed belt, and for replacing the motor reducer and/or performing any other work on the unit extremely quickly. Using a toothed belt is also particularly advantageous by involving no noticeable slack, so that the efficiency and reliability of unit 1 are comparable with those of known units, while those of unit 30 are even greater by the linkage mechanism between the motor reducer and gripping members comprising none of the gear transmissions invariably featured in all known inverter units. Moreover, a belt transmission provides for greatly enhancing the safety of the unit, by being more flexible than commonly used gear transmissions, so that the unit is arrested quickly in the event of any foreign bodies along the path of the gripping members. As compared with known solutions, a belt transmission also provides for reducing the noise level of the unit and so improving working conditions. Units 1 and 30 can be fitted to any existing machine with no alterations required to the machine structure, and in particular no structural alterations requiring further alterations to the machine to reassemble the original or any other known inverter unit. Clearly, changes may be made to units 1 and 30 as described herein without, however, departing from the scope of the claims. In particular, the motor reducer may be positioned otherwise than as described by way of example, providing its axis lies in a horizontal plane parallel to and a distance from hinge axis 8; and the two gears in unit 1 may be replaced with a different type of mechanical transmission, e.g. a straightforward angular transmission, a belt transmission, or a worm-helical gear transmission. In the latter case, the axis of the motor extends perpendicularly to hinge axis 8.

Claims: An inverter unit (1; 30) for a machine for molding glass articles, the unit (1) comprising a supporting frame (2); gripping means (13) connected to the frame (2) to rotate about a horizontal hinge axis (8) and transfer, in use, parisons from a parison mold to a finish mold; a motor (28) for powering said gripping means (13) and having an output shaft (27) rotating about a respective axis (25); and a mechanical transmission (17, 23; 33) interposed between said motor (28) and said gripping means (13); characterized in that the axis (25) of said output shaft (27) extends at a distance from said hinge axis (8) and lies in a substantially horizontal plane. A unit as claimed in Claim 1, characterized in that the axis (25) of said output shaft (27) is parallel to said hinge axis (8). A unit as claimed in Claim 1 or 2, characterized in that said frame (2) comprises a bottom fastening portion (3) for connection to a structure of said molding machine; the output shaft (27) of said motor (28) and said hinge axis (8) being located on opposite sides of said bottom fastening portion (3). A unit as claimed in any one of the foregoing Claims, characterized in that said mechanical transmission (17, 23; 33) comprises belt transmission means (23; 33). A unit as claimed in Claim 4, characterized in that said belt transmission means comprise a single transmission belt (26; 33). A unit as claimed in Claim 5, characterized in that said transmission belt (26; 33) is a toothed belt. A unit as claimed in Claim 6, characterized in that said mechanical transmission (17, 23; 33) also comprises a driven shaft (19; 7) parallel to the axis (25) of said output shaft (27); said belt transmission means comprising two pulleys (22; 32) (24), one fitted to said driven shaft (19; 7) and the other to said output shaft (27); and said belt (26; 33) being looped about said two pulleys (22; 32) (24); said driven shaft being an intermediate shaft (19). extending parallel to and a transverse distance from said hinge axis (8); said mechanical transmission also comprising further transmission means (17) interposed between said intermediate shaft (19) and said gripping means. A unit as claimed in Claim 7, characterized in that said further transmission means (17) are gear transmission means. A unit as claimed in Claim 8, characterized in that said gear transmission means comprise one pair of gears (16)(18) meshing with each other. A unit as claimed in Claim 6, characterized in that said mechanical transmission (17, 23; 33) also comprises a driven shaft (19; 7) parallel to the axis (25) of said output shaft (27); said belt transmission means comprising two pulleys (22; 32) (24), one fitted to said driven shaft (19; 7) and the other to said output shaft (27); and said belt (26; 33) being looped about said two pulleys (22; 32) (24); said driven shaft (7) extending coaxially with said hinge axis (8) and said gripping means (13) being carried by said driven shaft (7). A unit as claimed in Claim 10, characterized in that said belt transmission means also comprise a transmission roller (35) located outwards of said belt (33) and along a branch (34) of the belt (33).

Inventors: ARMANDO LORENZO, BAJO ROLANDO, LISCO GABRIELE, ARMANDO, LORENZO, BAJO, ROLANDO, LISCO, GABRIELE
Applicants: BOTTERO SPA, BOTTERO S.P.A.
Application year: 2001
Main classification: C03B9
IPC codes: C03B9