LIFTING GEAR

Abstract

The disclosure relates to a lifting gear for opening and closing a workstation of a packaging machine, wherein the lifting gear includes a stationarily mounted base, a lifting platform mounted to be height adjustable with respect to the base along a lifting axis for supporting a lower tool part of the workstation, and an adjusting mechanism comprising a drive unit and a toggle means on which the lifting platform is mounted, wherein the adjusting mechanism furthermore includes a pressure part coupled with the toggle means and adjustable by means of the drive unit along the lifting axis, wherein by the displacement of said pressure part along the lifting axis, the toggle means can be actuated for a height adjustment of the lifting platform.

Claims

1. A lifting gear for opening and closing a workstation of a packaging machine, the lifting gear comprising: a stationarily mountable base; a lifting platform mounted to be height adjustable with respect to the base along a lifting axis for supporting a lower tool part of the workstation; and an adjusting mechanism comprising a drive unit and a toggle means on which the lifting platform is mounted, wherein the adjusting mechanism furthermore includes a pressure part coupled with the toggle means and adjustable by means of the drive unit, wherein by displacement of the pressure part, the toggle means is actuatable for a height adjustment of the lifting platform along the lifting axis.

2. The lifting gear according to claim 1, wherein the toggle means includes at least three separate toggle joints which are actuatable together by means of a displacement of the pressure part.

3. The lifting gear according to claim 2, wherein the toggle joints are arranged at a predetermined angle with respect to each other such that their common actuation functions as a linear guide for adjusting the lifting platform along the lifting axis.

4. The lifting gear according to claim 1, wherein the toggle means includes four separate toggle joints which are arranged in pairs cross-over in first and second adjusting planes.

5. The lifting gear according to claim 4, wherein the first and second adjusting planes intersect along a drive axis of the drive unit.

6. The lifting gear according to claim 1, wherein the toggle means includes three or four separate toggle joints, wherein toggle joints arranged in pairs next to each other are adjustable in respective adjusting planes which intersect along an intersection line extending in parallel to a drive axis of the drive unit.

7. The lifting gear according to claim 1, wherein the pressure part is present in the form of a plate.

8. The lifting gear according to claim 7, wherein the toggle means is circumferentially fixed to the plate.

9. The lifting gear according to claim 1, wherein the pressure part is present in the form of a plate and has an X-shaped or O-shaped contour.

10. The lifting gear according to claim 1, wherein the pressure part has an X-shaped contour.

11. The lifting gear according to claim 1, wherein the pressure part has an O-shaped contour.

12. The lifting gear according to claim 1, wherein the pressure part is adjustable, by means of the drive unit, between a lowered position in which the pressure part is positioned approached to the base and a lifted position in which the pressure part is positioned to be spaced apart from the base.

13. The lifting gear according to claim 12, wherein the pressure part is positioned in the lowered position underneath lower attachment bearings provided at the base for the toggle means, and/or the pressure part is positioned in the lifted position above the lower attachment bearings provided at the base for the toggle means.

14. The lifting gear according to claim 1, wherein the toggle means is movable between a retracted position and an extended position in which upper attachment bearings provided at the lifting platform for the toggle means have a different distance with respect to each other than lower attachment bearings provided at the base for the toggle means.

15. The lifting gear according to claim 1, wherein the pressure part is adjustable along the lifting axis in a linearly guided manner.

16. The lifting gear according to claim 15, wherein the pressure part is guided along the lifting axis on the drive side only by a retractable and extendable piston of the drive unit, or the lifting gear has at least one separate linear guidance for the pressure part.

17. The lifting gear according to claim 1, wherein the drive unit is embodied as a pneumatic cylinder or as an electric cylinder.

18. The lifting gear according to claim 1, wherein the toggle means comprises a linkage.

19. A deep-drawing packaging machine or tray sealing machine comprising the lifting gear according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Below, the disclosure will be illustrated more in detail with reference to embodiments represented in the figures. The figures show in detail:

[0036] FIG. 1 shows a perspective view of a deep-drawing packaging machine;

[0037] FIG. 2 shows a perspective view of a tray sealing machine;

[0038] FIG. 3A shows a lifting gear according to the disclosure in an opened position;

[0039] FIG. 3B shows the lifting gear according to the disclosure in a closed position;

[0040] FIG. 4 shows a plan view representation of the toggle joints according to an arrangement according to the embodiment;

[0041] FIG. 5 shows a plan view representation of the toggle joints according to a further arrangement according to the embodiment; and

[0042] FIG. 6 shows a plan view representation of the toggle joints according to a further arrangement according to the embodiment.

[0043] Equal components are always provided with equal reference numerals in the figures.

DETAILED DESCRIPTION

[0044] FIG. 1 shows an intermittently operating deep-drawing packaging machine 1 in a perspective view. This deep-drawing packaging machine 1 includes a forming station 2, a sealing station 3, a cross cutter 4 and a longitudinal cutter 5 which are arranged in this sequence at a machine frame 6 in a direction of transport R. At the entry side, a feed roller 7 is located at the machine frame 6, a lower foil 8 being reeled off from said roller. Furthermore, the deep-drawing packaging machine 1 includes a transport chain 11 which grips the lower foil 8 and transports it further in the direction of transport R per main cycle, in particular transport chains or clamping chains 11, respectively, arranged at both sites.

[0045] In the represented embodiment, the forming station 2 is embodied as a deep-drawing station in which cavities are formed in the lower foil 8 by deep-drawing, for example by means of compressed air and/or a vacuum. The forming station 2 can be designed such that several cavities are formed next to each other in the direction perpendicular to the direction of transport R. In the direction of transport R downstream of the forming station 2, a filling section 12 is provided in which the cavities formed in the lower foil 8 are filled with products.

[0046] The sealing station 3 has a hermetically closable chamber 3a in which the atmosphere in the cavities is e.g., evacuated and/or can be replaced by a replacement gas or a gas mixture by gas flushing before the sealing with an upper foil 10 discharged by an upper foil retainer 9.

[0047] The transverse cutter 4 can be embodied as a stamping machine which cuts through the lower foil 8 and the upper foil 10 between adjacent cavities in a direction transverse to the direction of transport R. In the process, the transverse cutter 4 operates such that the lower foil 8 is not cut through across its total width, but is not cut through at least in an edge region. This permits a controlled further transport through the transport chain 11.

[0048] The longitudinal cutter 5 can be embodied as a knife arrangement by which the lower foil 8 and the upper foil 10 are cut through between adjacent cavities and at the lateral edge of the lower foil 8 in the direction of transport R so that singled packages are present downstream of the longitudinal cutter 5.

[0049] The right and left transport chains 11 of the deep-drawing packaging machine 1 which grip the lower foil 8 on both sides are each guided in a chain guide 13. These chain guides 13 are protected to the outside each by a side covering 14 of the deep-drawing packaging machine 1 and are optionally fixed to the side covering 14. The side covering 14 can be a panel.

[0050] The deep-drawing packaging machine 1 furthermore includes a control unit 19. The latter has the task of controlling and monitoring the processes running in the deep-drawing packaging machine 1. A display device 20a with operational controls 20b serves to visualize or influence the process flows in the deep-drawing packaging machine 1 for or by an operator.

[0051] FIG. 2 shows a tray sealing machine 15 also referred to as “tray sealer” by experts. This tray sealing machine 15 has a feed belt 16, a sealing station 17 and a discharge belt 18 which are arranged in this sequence at a machine frame 21 in the direction of transport R. Furthermore, the tray sealing machine 15 comprises a gripper means 22 by means of which prefabricated trays S can be fetched from the feed belt 16 and transported to the sealing station 17 for a sealing process performed therein. Furthermore, the gripper means 22 is embodied to grip trays S sealed within the sealing station 17 and deliver them to the discharge belt 18 for transporting them away on the latter. The unsealed trays S positioned within the sealing station 22 can be sealed by means of an upper foil 23 performed by the sealing station 22.

[0052] FIG. 3A shows a lifting gear 24 for opening and closing a workstation of a packaging machine. The workstation can be present, for example, as a sealing station 3 of the deep-drawing packaging machine 1 shown in FIG. 1 or as a sealing station 17 of the tray sealer 15 shown in FIG. 2.

[0053] In FIG. 3A, the lifting gear 24 is represented in an opened position 51. The lifting gear 24 has a base 25, a lifting platform 26 mounted to be height adjustable with respect to the base 25 along a lifting axis H on which a lower tool part 27 present in the form of a tray seat 31 is positioned. The lifting gear 24 furthermore comprises an adjusting mechanism 28 which includes a drive unit 29 and a toggle means 30. In FIG. 3A, the tray seat 31 is embodied for receiving cavities which are formed along the deep-drawing packaging machine 1.

[0054] By means of the lifting gear 24, the lower tool part 27 can be brought together with an upper tool part 32 arranged above it for a packaging process, for example a sealing process. The lifting gear 24 is fixed to a machine frame 33 on both sides. The base 25 of the lifting gear 24 is connected to the machine frame 33 by means of supporting rods 34, i.e., it is stationarily mounted relative to the machine frame 33. During the operation of the lifting gear 24, i.e., during the alternating lifting and lowering of the lifting platform 26, the base 25 remains stationarily mounted.

[0055] At lower ends of the supporting rods 34, two supports 35 are fixed transverse to the direction of transport R. On the two supports 35, a base plate 36 is mounted. The supporting rods 34, the two supports 35 and the base plate 36 fixed thereto form a good bearing base 25 fixed to the machine frame 33.

[0056] FIG. 3A furthermore shows that the drive unit 29 is fixed to the base plate 36. In FIG. 3A, the drive unit 29 is embodied as a piston cylinder unit 37. The piston cylinder unit 37 is, for example, a pneumatic cylinder or an electric cylinder which is provided for adjusting the lifting platform 26 along the lifting axis H.

[0057] FIG. 3A also shows that the adjusting mechanism 28 includes a pressure part 38 coupled with the toggle means 30 and adjustable by means of the drive unit 29 along the lifting axis H, wherein by the displacements of said pressure part along the lifting axis H, the toggle means 30 can be actuated for a height adjustment of the lifting platform 26.

[0058] FIG. 3B shows the lifting gear 24 in a closed position S2 in which the lower tool part 27 and the upper tool part 32 are brought together. For this, the pressure part 38, represented in a lowered position P1 in FIG. 3A in which it is positioned approached to the base plate 36, was adjusted to the lifted position P2 represented in FIG. 3B in which the pressure part 38 is positioned spaced apart from the base plate 36. In FIG. 3B, the toggle means 30 is now adjusted to an extended position M2 compared to a retracted position M1 shown in FIG. 3A.

[0059] In FIG. 3B, it can be clearly seen that the toggle means 30 has four separate toggle joints 39a, 39b, 39c and 39d (hereinafter: toggle joints 39a to 39d). The toggle joints 39a to 39d are arranged in pairs cross-over in a first and a second adjusting plane E1, E2. In particular, the respective toggles of the two toggle joints 39a and 39c can be pivoted in the adjusting plane E1, and the respective toggles of the other two toggle joints 39b and 39d can be pivoted in the adjusting plane E2. The two adjusting planes E1, E2 are arranged at a predetermined angle α with respect to each other. The angle α is present as an acute angle and is preferably 20°. According to FIG. 3B, the two adjusting planes E1, E2 intersect along a drive axis A of the drive unit 29.

[0060] FIG. 3B also shows that the piston cylinder unit 37 includes an extendable piston 40 which is adjustable along the drive axis A which is flush with the lifting axis H. The pressure part 38 fixed to an upper end of the piston 40 causes, by its displacement along the drive axis A, the toggle means 30 to move between the retracted position M1 of FIG. 3A and the extended position M2 of FIG. 3B. The toggle joints 39a to 39d of the toggle means 30 can thereby be adjusted synchronously to move the lifting platform 26 mounted thereon along the lifting axis H.

[0061] FIG. 3B also shows that in the extended position M2 of the toggle means 30, upper attachment bearings 41a, 41b have a distance a with respect to each other. Furthermore, FIG. 3B shows that lower attachment bearings 42a, 42b provided at the base 25 for the toggle means 30 have a distance b with respect to each other. The distance a of the upper attachment bearings 41a, 41b shown in FIG. 3B is smaller than the distance b present between the lower attachment bearings 42a, 42b. With this configuration, i.e., with the different distances a, b, during the lifting of the pressure part 38 via the toggle means 30, a centering function for the lifting platform 26 adjustable therewith results, so that at each lifting, it comes to a standstill at a predetermined position, i.e., at each lifting, the lower tool part 27 positioned thereon is precisely brought together with the upper tool part 32 arranged above it.

[0062] In FIGS. 3A and 3B, a linear guide 43 positioned next to the piston cylinder unit 37 is provided on the base plate 36. Two such linear guides 43 could also be provided on the base plate 36 on opposite sides of the piston 40. Nevertheless, the adjusting mechanism 28 also works without the separate linear guide 43. Here, a guided height adjustment of the lifting platform 26 along the lifting axis H results exclusively by the piston 40 of the piston cylinder unit 37 extendable along the drive axis A and the respective toggle joints 39a to 39d.

[0063] FIG. 4 shows the toggle means 30 mounted in FIG. 3B in a plan view. The intersection line formed by the two adjusting planes E1, E2 here corresponds to the drive axis A of the drive unit 29. The two adjusting planes E1, E2 intersect at an angle α. The angle α is in particular 80° to 100°.

[0064] FIG. 5 shows another arrangement of the four toggle joints 39a to 39d. The toggle joints 39a to 39d are adjustably mounted in respective adjusting planes Ea, Eb, Ec, Ed. The two adjusting planes Eb, Ec of the toggle joints 39b, 39c intersect in an intersection line B. The two adjusting planes Ea, Ed of the toggle joints 39a, 39d intersect in an intersection line C. The two intersection lines B, C extend in parallel to the drive axis A of the drive unit 29. FIG. 5 furthermore shows that the two intersection lines B, C extend equidistantly with respect to the drive axis A. This permits a particularly robust displacement of the lifting platform 26 because a stable guidance automatically results for it. The respective intersection line pairs Ea, Ed and Eb, Ec in particular each intersect at an angle amounting to 80° to 100°.

[0065] FIG. 6 shows the two toggle joints 39b, 39c according to the arrangement of FIG. 5 in a plan view. FIG. 6 furthermore shows a third toggle joint 39e which replaces the two toggle joints 39a, 39b shown in FIG. 5. These three toggle joints 39b, 39c, 39e include adjusting planes Eb, Ec, Ee which intersect along one single intersection line D extending in parallel to the drive axis A of the drive unit 29. Here, the toggle joint 39e is mounted such that the drive axis A of the drive unit 29 is located in its adjusting plane Ee. Even if only the three toggle joints 39b, 39c, 39e are employed, a robust, precisely guided adjustability results for the lifting platform 26 thereby. The arrangement of the respective toggle joints 39b, 39c, 39e could be such that their three adjusting planes Eb, Ec, Ee each intersect at an angle of 120° with respect to each other.