Rotary disk cutter blade

Abstract

The invention relates to a rotary disk cutter blade having a circular outer contour, an axis of rotation, and a central opening which has a form-fitting inner contour. The invention also relates to a hub for the blade, a rotary disk cutter arbor, and a packaging machine.

Description

[0001] Roller shear cutting blade

[0002] The present invention relates to a rotary shear cutting blade with a circular outer contour, a rotational axis, and a central opening having an inner contour. The present invention also relates to a rotary shear cutting shaft and a packaging machine.

[0003] Such rotary shear cutting blades are known from the prior art and are used in packaging machines to separate finished packages by making a cut parallel to the direction of travel of the packaging material, for example, a film. They work together with a so-called counter blade to perform the cutting action. Typically, several of these rotary shear cutting blades are arranged parallel to each other on a rotary shear cutting shaft. Since the rotary shear cutting blades become dull over time, they must be arranged on the rotary shear cutting shaft in a replaceable manner. Different types of packaging and / or different packaging formats can be produced on such packaging machines. When changing production, the position of the rotary shear cutting blades relative to the longitudinal axis of the rotary shear cutting shaft must be changed.Both changing the blade and changing the position of the rotary shear cutting blade on the rotary shear cutting shaft should be possible as quickly and precisely as possible.

[0004] The object of the present invention was therefore to provide a rotary shear cutting knife and a rotary shear cutting shaft and the associated packaging machine with which a knife change and / or a format change can be carried out quickly and precisely.

[0005] The problem is solved with a rotary shear cutting knife having a circular outer contour, an axis of rotation and a central opening having an inner contour, wherein the inner contour has at least two recesses and one recess is essentially trapezoidal and the other recess is essentially triangular.

[0006] The descriptions given for this embodiment of the present invention apply equally to the other objects and vice versa. Features disclosed in connection with the rotary shear cutting blade can be combined with features of the rotary shear cutting shaft and vice versa. This object of the present invention relates to a rotary shear cutting blade, preferably the so-called lower blade of the longitudinal cutter, which is used for longitudinal cutting in a packaging machine. It interacts with a counter blade, which is preferably arranged above it, in a cutting action. Both blades rotate during the cutting process. The rotary shear cutting blade according to the invention has a preferably circular outer contour. In the center of the blade, around its axis of rotation, an opening is provided which receives a shaft on which the rotary shear cutting blade is arranged. This opening has an inner contour.The opening extends around the axis of rotation of the knife and preferably follows the outer contour of the shaft in sections.

[0007] According to the invention, the inner contour has at least two recesses, one of which is essentially trapezoidal and the other essentially triangular. In the area of ​​the recesses, the distance of the inner contour from the axis of rotation of the roller shear cutting blade is greater than in the area of ​​the inner contour of the opening surrounding the recess.

[0008] Furthermore, according to the invention, one of the two inner contours is essentially trapezoidal, with the longer longitudinal side of the trapezoid pointing towards the axis of rotation of the roller shear cutting blade. Preferably, the corners of the trapezoid are rounded. Preferably, the short longitudinal side of the trapezoid, also referred to as the "base" in the present application, is provided with a curvature, at least in sections.

[0009] According to the invention, at least one other recess is essentially triangular in shape, with the corners of the triangle preferably being rounded.

[0010] According to a further or preferred embodiment of the invention, a positive locking element, preferably a chamfer, is provided on the inner contour. This positive locking element allows the roller shear cutting blade to be attached to a roller shear cutting shaft and / or for the transmission of torque. The positive locking element is preferably a chamfer, which may have a circular segment or polygonal cross-section. The positive locking element on the inner contour may extend over its entire length or be present only in sections. In particular, the positive locking element is provided in the area of ​​the triangular recess.

[0011] Preferably, the trapezoidal recess and a triangular recess are opposite each other, in particular diametrically opposite each other.

[0012] According to a further preferred embodiment, the essentially trapezoidal recess is framed by preferably two further essentially triangular recesses. In this case, therefore, four recesses are provided on the inner contour.

[0013] Alternatively, the inner contour has only essentially triangular recesses, in particular three essentially triangular recesses. These then secure the roller shear cutting blade to the roller shear cutting shaft and transmit a torque.

[0014] The problem is also solved with a roller shear cutting shaft on which a plurality of the roller shear cutting knives according to the invention are arranged and which has a hub for each roller shear cutting knife with which the roller shear cutting knife is attached to the roller shear cutting shaft.

[0015] The descriptions given for this embodiment of the present invention apply equally to the other items and vice versa. Features disclosed in connection with the roller shear cutting blade can be combined with features of the roller shear cutting shaft and vice versa.

[0016] This embodiment of the present invention relates to a rotary shear cutting shaft on which a plurality of rotary shear cutting blades are arranged. Each rotary shear cutting blade has a hub by which the blade is attached to the shaft. A torque is also transmitted to the blade via the hub. The hub can be moved along the longitudinal axis of the rotary shear cutting shaft and fixed in place.

[0017] Preferably, the hub has a cam that interacts with the substantially trapezoidal recess to transmit torque. Preferably, the base of the substantially trapezoidal recess does not rest against the cam.

[0018] Preferably, a clamping means is provided on the hub for each triangular recess, which reversibly clamps together with the roller shear cutting blade and thereby secures the roller shear cutting blade to the roller shear cutting shaft and / or transmits a torque.

[0019] According to a preferred embodiment, the clamping means can be reversibly moved from a non-clamping to a clamping position and vice versa.

[0020] Another object of the present invention is a packaging machine for producing packaging, with a sealing station that seals a material web, in particular a film web, to a packaging recess, wherein the packaging recess may optionally be deep-drawn into the material web, in particular a film web, and wherein the packaging machine has a roller shear cutting shaft according to the invention.

[0021] Such a packaging machine is, in particular, a thermoformer or a trayformer. In a thermoformer, for example, a bottom film web is unwound from a supply roll and preferably transported intermittently along the packaging machine. In a forming station, a packaging cavity can first be formed in the bottom film web, which is then filled with a product, especially a food item. Subsequently, the packaging cavity is sealed in a sealing station with one or more top films, which are sealed to the bottom film. The top film web is also unwound from a supply roll. The film web(s) are transported by endless chains arranged to the right and left of the respective film web. At least one gear is provided for each chain at both the beginning and the end of the packaging machine, around which the respective chain is deflected.At least one of these gears, or gears arranged elsewhere, is driven. The gears in the infeed and / or outfeed sections can be connected to each other, preferably by a rigid shaft. Each chain has a plurality of clamping elements that grip the underlayer film in the infeed section at the so-called edge strip and transmit the movement of the transport element to the underlayer film. In the outfeed section of the packaging machine, the clamping connection between the transport element and the respective film film is released. Downstream of the sealing station, a cross cutter is provided that cuts apart the individual rows of packages of a given format perpendicular to the transport direction of the film films. Subsequently, the blades of a longitudinal cutter divide these rows into individual packages.These knives are the roller shear cutting knives according to the invention, which are part of the roller shear cutting shaft according to the invention.

[0022] The inventions are explained below with reference to the figures. These explanations are merely exemplary and do not limit the general concept of the invention. The explanations apply equally to all aspects of the present invention.

[0023] Figure 1 shows the packaging machine according to the invention.

[0024] Figure 2 shows the rotary shear cutting knife.

[0025] Figure 3 shows the basic body of the hub.

[0026] Figures 4-10 each show a representation of the roll shear cutting shaft. Figure 1 shows the packaging machine 1 according to the invention, in this case a so-called thermoformer, which has a thermoforming station 2, a filling station 7, and a sealing station 15. A bottom film web 8, here a plastic film web 8, is unwound from a supply roll and transported intermittently along the packaging machine according to the invention from right to left. The film roll is generally mounted on a shaft. In each cycle, the bottom film web 8 is advanced by one feed, with several feeds being required to produce a finished package. For this purpose, the packaging machine has two transport means (not shown), in this case two endless chains, which are arranged to the right and left of the bottom film web 8.At both the beginning and end of the packaging machine, at least one gear is provided for each chain around which the respective chain is deflected. At least one of these gears is driven. The gears in the inlet and / or outlet areas can be connected to each other, preferably by a rigid shaft. Each transport element has a plurality of clamping elements that grip the underlayer 8 in the inlet area 19 and transmit the movement of the transport element to the underlayer 8. In the outlet area of ​​the packaging machine, the clamping connection between the transport element and the underlayer 8 is released. A heating element is provided downstream of the inlet area 19 to heat the film 8, particularly when it is stationary.In the thermoforming station 2, which here has an upper die 3 and a lower die 4 that has the shape of the packaging tray to be produced, the packaging trays 6 are formed in the heated film web 8. Typically, a format of packaging trays consisting of several rows and / or several columns, each with multiple trays, is produced simultaneously during a single cycle. The lower die 4 is arranged on a lifting table 5, which, as symbolized by the double arrow, is vertically adjustable by a lifting device. Before each film feed, the lower die 4 is lowered and then raised again. In the next stage of the packaging machine, the packaging trays are then filled with the product 16 in the filling station 7.In the subsequent sealing station 15, which also consists of an upper tool 12 and a vertically adjustable lower tool 11, a top film 14 is bonded to the bottom film web 8, for example by sealing. In the sealing station as well, the upper tool and / or the lower tool are lowered or raised before and after each film transport. The top film 14 is also unwound from a film roll mounted on a shaft and can be guided in transport devices or transported by conveyor chains, whereby these transport devices then extend only from the sealing station and, if necessary, downstream. Otherwise, the descriptions given for the transport devices of the bottom film apply. The top film can also be heated with a heating medium and deep-drawn.For sealing, a heated sealing frame, for example, is provided as the lower tool 11. This frame has an opening for each packaging cavity into which the packaging cavity is immersed during sealing, i.e., during the upward movement of the lower sealing tool. For sealing, the upper and lower film webs are pressed together between the upper and lower tools 12, 11 and bond under the influence of heat and pressure. After sealing, the tools 11, 12 are moved apart vertically again. A dancer is preferably provided between the respective supply roll and the sealing tool. This dancer compensates for the intermittent feed of the lower film 8 and thus the intermittent release of the upper film web 14. The dancer can serve as a film web storage unit and / or to generate a specific film tension.Those skilled in the art understand that several top films may be present, for example, in a multi-layer package or a package with multiple top films. Preferably, a dancer is provided along each top film. Those skilled in the art further understand that a dancer may also be provided in the area of ​​the bottom film 8, preferably downstream of its feed roll. Further along the packaging machine, the finished packages are separated, which in this case is done with the cross cutter 18 and the longitudinal cutter 17. In this case, the cross cutter 18 can also be raised and lowered by a lifting device 9. The longitudinal cutter has several rotary shear cutting blades 30. The rotary shear cutting blades of the longitudinal cutter and the associated rotary shear cutting shaft are explained with reference to the following figures.

[0027] Figure 2 shows the rotary shear cutting blade 30 according to the invention, which has a circular outer contour with which the material web 8, 14 is cut. The rotary shear cutting blade 30 rotates about its axis of rotation 45 during cutting. In its center, the rotary shear cutting blade 30 has an opening 41 that accommodates a shaft (not shown). This opening has an inner contour 39 which, in this case, has four recesses 40, 42, 43. One recess 43, which in this case is located at the 12 o'clock position, is essentially trapezoidal. As will be explained in more detail later, the essentially trapezoidal recess interacts with a cam 44, which is connected to a shaft, to transmit a torque from the shaft to the rotary shear cutting blade.The short longitudinal side 46 of the substantially trapezoidal recess, also referred to as the base of the trapezoidal recess 43, is preferably curved so that this surface does not abut, or does not fully abut, the cam 44. The other recesses 42 are substantially triangular, with one corner of the triangle being provided with a radius. In the present example, three triangular recesses 42 are provided, although those skilled in the art understand that two or only one substantially triangular recess 42 may also be provided. It is also possible that more than three triangular recesses 42, for example four, five, or six recesses 42, are provided. In the case that only one recess 42 is provided, it should be arranged opposite the substantially trapezoidal recess 43 with respect to the opening 41.It is also conceivable that only substantially triangular recesses 42 are provided and no substantially trapezoidal recess 43. In this case, at least two, preferably three, triangular recesses 42 are preferred.

[0028] Figure 3 shows a hub 31. The hub can be reversibly connected to a shaft by means of a clamping device 33, here for example a clamping ring. The hub 31 has a cam 44 which interacts with the recess 43 in the roller shear cutting blade. Preferably, at least one, here three, contact surfaces 47 are also provided for a clamping device 32, with which the roller shear cutting blade according to Figure 2 is attached to a shaft.

[0029] Figures 4-10 show the roller shear cutting shaft 34 according to the invention, on which a roller shear cutting blade 30 is attached by means of a hub 31. The hub 31 can be reversibly connected to a shaft by means of the clamping means 33a. The blade 30 is fixed to the hub 31 by means of the clamping holders 32. These can be moved from a retracted position to a clamping position, as shown in Figure 6, and fixed there, for example, by means of the fastening means 33b. In the illustrated embodiment, it is advantageous if the clamping holder 32, which is diametrically opposite the cam 44 (six o'clock position), engages with the blade first, because this pulls the recess 43 against the cam 44, creating a force-fit and form-fit connection.Figure 6 also shows that it is advantageous if a gap 37 remains between the base of the essentially trapezoidal recess 43 and the cam 44 even after clamping. This ensures a backlash-free positive fit between the recess and the cam.

[0030] The attachment of the knife 30 to the hub is particularly well shown in Figure 7. Into the

[0031] The inner contour 39 incorporates a positive locking element 36, here a chamfer, into which the clamping holder 32 engages when moved outwards as shown in Figure 6. The movement of the clamping holder 32 is achieved, for example, by turning the screw 33c, which is then fixed in its desired position by the element 33b.

[0032] To change the blade 30, the clamping holder is then returned to its retracted position, as shown in Figures 8 and 9. A blade can now be moved completely over the hub.

[0033] Figure 10 illustrates a knife change. The knife 30 can be moved completely over the hub 31, optionally to either side. This allows all knives to be removed from the hubs 31 and the shaft 34 one after the other or as a unit, with the hubs remaining in their set positions on the shaft. The hubs 31 would only be moved to a new longitudinal position on the shaft when the format changes, not for a simple knife change.

[0034] Reference symbol list:

[0035] 1 packaging machine

[0036] 2 forming station, deep-drawing station

[0037] 3 Upper tool of the deep drawing station

[0038] 4 lower tools of the deep drawing station

[0039] 5 Lifting table, carrier of a tool of the sealing, deep drawing station and / or the cutting device

[0040] 6 packaging trays

[0041] 7 first filling station

[0042] 8 film layer, underfilm layer

[0043] 9 Lifting device

[0044] 10 longitudinal cutting cassettes

[0045] 11 Sub-tools of the sealing station

[0046] 12 Upper tool of the sealing station

[0047] 13

[0048] 14 Top film layer, lid film

[0049] 15 Sealing Station

[0050] 16 Packaged goods

[0051] 17 longitudinal cutters

[0052] 18 cross cutters

[0053] 19 Entrance area

[0054] 30 knives, lower knives

[0055] 31 hub

[0056] 32 clamping devices, clamping holders

[0057] 33, 33a, 33b, 33c Fasteners, clamping devices, sliding devices, screws

[0058] Threaded pin

[0059] 34 Shaft, knife shaft

[0060] 35a Direction, locking direction

[0061] 35b direction, release direction

[0062] 36 Positive locking devices, chamfer, spring

[0063] 37 gap, free space

[0064] 38 Direction, direction of movement (of the knife)

[0065] 39 Inner contour of the knife,

[0066] 40 Exclusion

[0067] 41 Opening

[0068] 42 Triangular recess Trapezoidal recess Cam Axis of rotation Base of the trapezoidal recess 43 Contact surfaces

Claims

Patent claims:

1. Roller shear cutting blade (30) with a preferably circular outer contour, an axis of rotation and a central opening (41) which has an inner contour (39), characterized in that the inner contour (39) has at least two recesses (40, 42, 43), wherein one recess (43) is essentially trapezoidal and the other recess (42) is essentially triangular.

2. Roller shear cutting blade (30) according to claim 1 or the preamble of claim 1, characterized in that a form-fitting means (36), preferably a chamfer, is provided on the inner contour (39).

3. Roller shear cutting knife (30) according to one of the preceding claims, characterized in that the trapezoidal recess (43) and the triangular recess (42) are opposite each other.

4. Roller shear cutting knife (30) according to one of the preceding claims, characterized in that the trapezoidal recess (43) is framed by preferably two further triangular recesses (42).

5. Roller shear cutting blade (30) according to one of the preceding claims, characterized in that the trapezoidal recess (43) has a curved base (46).

6. Roller shear cutting shaft (34) on which a plurality of roller shear cutting knives (30) according to one of the preceding claims are arranged and which has a hub (31) for each roller shear cutting knife (30) with which the roller shear cutting knife (30) is attached to the roller shear cutting shaft (34).

7. Roller shear cutting shaft (34) according to claim 6, characterized in that the hub (31) has a cam (44) which interacts with the trapezoidal recess (43) to transmit torque.

8. Roller shear cutting shaft (34) according to claim 6 or 7, characterized in that a clamping means (32) is provided on the hub for each triangular recess (42), which clamps together with the roller shear cutting knife (30).

9. Roller shear cutting shaft (34) according to claim 8, characterized in that the clamping means can be reversibly moved into a clamping position.

10. Packaging machine (1) for producing packaging, comprising a sealing station (15) which seals a film web (14) to a packaging trough (6), wherein the packaging trough may optionally have been deep-drawn into a film web (8), characterized in that the packaging machine has a roller shear cutting shaft (34) according to one of claims 6 - 9.

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