EP4029817B1 - Rotary frame structure for web poition control devices - Google Patents

Description

The invention relates to a rotating frame construction for web running control devices, with a support frame and a rotating frame parallel thereto, which carries an inlet roller and an outlet roller for a web to be controlled and is pivotally held on the support frame by a bearing, the bearing having a virtual pivot point which is through Control surfaces of one frame are defined, which are scanned by cam followers of the other frame, and wherein the frames are held in parallel alignment by support rollers of one of the frames and associated running surfaces of the other frame and are pivotally connected to one another by a drive.

When processing running webs of material, for example in rotary printing machines, it is generally necessary to control or regulate the web run so that the web does not migrate in the direction transverse to the running direction. For this purpose, the web is threaded through the rotating frame construction in such a way that it is deflected by, for example, 90° on the inlet roller and the outlet roller. If the running direction deviates from the desired direction, the rotating frame, which carries the inlet roller and the outlet roller, is pivoted relative to the support frame so that the inlet and outlet rollers assume a different orientation and direct the web back in the desired direction.

In most conventional rotating frame designs, the inlet roller and the outlet roller are arranged with parallel axes in a plane parallel to the rotating frame, but offset from the plane of the rotating frame to such an extent that the rollers are freely rotatable. The rotating frame and the support frame are designed to be approximately congruent and are also arranged in mutually offset planes so that they can be pivoted relative to one another. Overall, the rotating frame construction has a three-layer structure.

The pivot point about which the rotating frame is pivoted relative to the support frame should ideally be in the middle of the incoming web, so that the pivot axis is perpendicular to the plane of the rotating frame and tangential to the outer apex of the inlet roller. This means that when the rotating frame is pivoted, the incoming web remains practically stationary, while the outgoing web shifts in the desired direction.

A bearing with a virtual pivot point has the advantage that the ideal position for the pivot axis can be achieved without there being any mechanical axis or bearing elements at this point that would collide with the incoming web.

A rotating frame construction of the type mentioned at the beginning is in DE 20 2017 100 819 U1 described. The control surfaces that define the virtual pivot are formed by cylindrically curved walls centered on the virtual pivot. The associated curve followers are formed by sets of feeler rollers that roll on the walls on both the inside of the curvature and the outside of the curvature, so that the degrees of freedom of movement in the plane parallel to the frames are reduced to a degree of freedom of rotation. The running surfaces for the support rollers are formed by bearing plates running parallel to the frames, and the support rollers are each arranged on both sides of the bearing plate and roll on both surfaces of the bearing plate, so that the frames are held in a fixed position in the direction perpendicular to the frame planes and are not tilted against one another about an axis running parallel to the frame plane can be.

The object of the invention is to create a rotating frame construction with a simplified structure

This object is achieved according to the invention in that the control surfaces are three control cams which are formed on the outer edges of a cam plate rigidly held on one of the frames and of which two are located on one side of the cam plate and the third on the opposite side the cam plate, and that the other of the frames has three cam followers, each of which is assigned to one of the control cams.

In the construction according to the invention, the control surfaces can simply be formed by a single plate, which can be machined, for example, by laser cutting, so that the edges of the plate form the control curves with the desired curvature. Since the cam followers, for example feeler rollers, attack the control cams from opposite sides, the restriction of the degrees of freedom of movement parallel to the frame planes is achieved with only three cam followers. In this way, a smooth and therefore precisely controllable pivoting of the rotating frame is made possible.

Since at least parts of the support frame and the rotating frame, namely the cam plate and the cam followers, must lie in a common plane, a low overall height of the frame construction (when installed horizontally) is achieved, which means that you gain additional design freedom when installing the rotating frame construction in a machine.

Advantageous refinements are specified in the subclaims.

A particularly small construction can be achieved in that the support frame and the rotating frame lie almost in a common plane, with one frame (for example the rotating frame) surrounding the other frame (the supporting frame) at a distance.

The cam plate can either be part of the rotating frame or part of the support frame. For the sake of simplicity, only the case in which the cam plate is part of the rotating frame will be discussed below. The rotating frame, which surrounds the support frame with its outer edge, then has a horizontal bar on which the cam plate is arranged so that it is in turn surrounded by the parts of the support frame on which the cam followers are formed.

In an advantageous embodiment, the support rollers, with which the parallel alignment of the frames is ensured and which are arranged, for example, on the support frame, are each accommodated with little play in a slot which is formed in the other frame (the rotating frame) and whose parallel edges are the running surfaces for the support roller. In this way, a relative movement in the direction perpendicular to the frame planes can be prevented with just a single support roller, since this can only move in the slot parallel to the frame plane. A slight play between the support roller and the edges of the slot enables a low-friction rolling movement either on one edge or the other edge of the slot, depending on which of the two edges of the slot the support roller is pressed against. The game can be kept so small that it is smaller than a permissible tolerance for relative movement of the frames in the direction perpendicular to the frame planes.

This mechanism for parallel alignment of the frames can also be used with advantage regardless of the features of claim 1 described above. A rotating frame construction according to the preamble of claim 1 is also disclosed, which is characterized in that each of the support rollers is received with little play in a slot formed in the other frame, the parallel edges of which form the running surfaces.

If the cam plate is held on a bar that runs parallel to the frame plane of the rotating frame, the slots for the support rollers can be formed in connecting components that connect the cam plate to the bar. In this way, a particularly simple structure of the rotating frame construction can be achieved. The feeler rollers, which move along the edges of the cam plate, can be mounted on a plate of the carrier and can be rotated about vertical axes (with horizontal frame levels). Bracket brackets can also be mounted on this plate, on the vertical legs of which the support rollers are mounted with a horizontal axis of rotation and engage in the slots of the connecting component.

Due to unavoidable manufacturing tolerances, the bearing that defines the virtual pivot point has a certain amount of bearing play, which can affect the accuracy of the web tracking control. The drive, which pivots the rotating frame sometimes in one direction and sometimes in the other direction relative to the support frame, also generally has a certain amount of play. In an advantageous embodiment, the drive is self-holding at least in one direction. Both the bearing play and the drive play can then be eliminated simply by elastically bracing the frames against each other against the self-holding force of the drive. This measure can also be advantageous regardless of the features of claim 1 be. A rotating frame construction according to the preamble of claim 1 is therefore also disclosed, which is characterized in that the drive is self-holding at least in one direction and the frames are elastically biased against one another in the direction of rotation in which the drive is self-holding.

For example, the drive can be a linear drive that acts between two lever arms formed on the two frames. The elastic pretension can then be achieved, for example, with the help of a simple tension spring that pulls the two lever arms together.

An exemplary embodiment is explained in more detail below using the drawings.

Fig. 1

eine schematische Darstellung einer Drehrahmenkonstruktion in der Draufsicht;

Fig. 2

die Drehrahmenkonstruktion mit leicht verschwenktem Drehrahmen;

Fig. 3

eine Ansicht der Drehrahmenkonstruktion in Richtung der Pfeile III - III in Fig. 1;

Fig. 4

eine vergrößerte Seitenansicht der Drehrahmenkonstruktion in Richtung der Pfeile IV - IV in Fig. 1;

Fig. 5

einen Grundriss einer Grundplatte eines Tragrahmens;

Fig. 6

eine Lagerplatte des Tragrahmens in der Draufsicht;

Fig. 7

eine Frontansicht des Tragrahmens;

Figuren 8 und 9

Frontansichten zweier Befestigungsteile zur Befestigung einer Kurvenplatte am Drehrahmen; und

Fig. 10

einen Grundriss der Kurvenplatte.

Show it:

Fig. 1

a schematic representation of a rotating frame construction in a top view;

Fig. 2

the rotating frame construction with a slightly pivoted rotating frame;

Fig. 3

a view of the rotating frame construction in the direction of arrows III - III in Fig. 1 ;

Fig. 4

an enlarged side view of the rotating frame construction in the direction of arrows IV - IV in Fig. 1 ;

Fig. 5

a floor plan of a base plate of a support frame;

Fig. 6

a bearing plate of the support frame in plan view;

Fig. 7

a front view of the support frame;

Figures 8 and 9

Front views of two fastening parts for attaching a cam plate to the rotating frame; and

Fig. 10

a floor plan of the cam plate.

In Fig. 1 a top view shows a rotating frame construction with a support frame 10 and a rotating frame 12, which can be pivoted about a virtual pivot point P relative to the support frame. Fig. 2 shows the rotating frame construction with a slightly pivoted rotating frame. For better differentiation, all (stationary) parts belonging to the support frame 10 are shown in bolder lines than the parts that are movable with the rotating frame 12.

An inlet roller 14 and an outlet roller 16 are mounted in the rotating frame 12, over which a material web (not shown) is guided, the web path of which is to be controlled with the aid of the rotating frame construction. For example, the material web can be threaded upwards in an inverted U-shape (in Fig. 1 towards the viewer) run to the inlet roller 14, where it is deflected horizontally so that it runs to the outlet roller 16, where it is deflected again so that it then moves downwards.

The support frame 10 has a horizontal base plate 18, from which in Fig. 1 Most of it is covered by the rotating frame 12, so that only the left edge of the base plate 18 is visible. On the right in Fig. 1 the base plate 18 forms a lever arm 20, which protrudes beyond the side edge of the rotating frame 12 and is connected to a console or a lever arm 24 of the rotating frame via an articulated linear drive 22. When the linear drive 22 pulls the lever arms 20 and 24 together, the rotating frame 12 pivots about the pivot point P going vertical pivot axis, as in Fig. 2 is shown. This pivot axis forms a tangent to the inlet roller 14, so that the inlet roller and thus the incoming material web does not carry out any transverse movement when the rotating frame 12 is rotated, while the outlet roller 16 and the outgoing material web experience a position shift in the transverse direction.

The rotating frame 12 forms a trough-shaped, downwardly open housing 26, the upper wall of which forms a latch 28 for holding a cam plate 30 accommodated inside the housing 26, which is connected to the latch 28 via a vertical wall element 32 which is trapezoidal in plan.

The edge of the cam plate 30 forms on the in Fig. 1 lower side two circular arc-shaped control cams 34 and on the upper side another circular control cam 36. The control cams 34 and 36 are centered on the virtual pivot point P. In order to clarify the curvature of these control curves 34, 36, in Fig. 1 extended circular arc pieces (solid lines) shown. Each control cam 34, 36 is assigned a feeler roller 38, which is mounted on the support frame 10 so that it can rotate about a vertical axis. The three feeler rollers 38 rest on the edge of the cam plate 30 with practically no play, so that this cam plate and thus the entire rotating frame 12 can only carry out a circular movement around the virtual pivot point P relative to the support frame.

Four brackets 40 are welded onto the support frame 10, which protrude vertically from the base plate and on each of which a support roller 42 is mounted. Two of these support rollers 42 are in slots 44 ( Fig. 8 ) recorded, which run horizontally in the legs of the trapezoidal wall element 32. These legs of the wall element 32 are angled so that they run tangentially to an arc around the virtual pivot point P. If a downward (weight) force acts on the rotating frame 12, the upper edges of the slots 44 are pressed against the support rollers 42, so that the wall element 32 and thus the entire rotating frame 12 supported on the support rollers 42. If the rotating frame is now pivoted, a relative movement occurs between the support roller and the slot, and the support roller rolls off the upper edge of the slot.

In the event that an upward force acts on the rotating frame 12, the lower edges of the slots 44 are pulled against the support rollers 42, and during a rotational movement, the support rollers roll on these lower edges of the slots. The play of the support rollers 42 in the slots 44 is on the one hand so large that the support rollers can move with little friction, but on the other hand is so small that the vertical movement of the wall element 32 possible due to this play relative to the support frame remains within the permissible tolerance limits.

In the housing 26 of the rotating frame 12, another wall element 46 is accommodated, which is trapezoidal in plan, which is held firmly on the underside of the bolt 28, and in the angled legs of which horizontal slots 48 are also formed ( Fig. 9 ). Two of the four support rollers 42 are accommodated in these slots in the wall element 46. The legs of this wall element are also angled so that they run tangentially to an arc around the virtual pivot point P. The wall element 46 is therefore guided by the support rollers 42 in the same way and supported with little play as the wall element 32. Overall, the engagement of the support rollers 42 in the slots 44, 48 prevents a vertical movement of the rotating frame relative to the support frame, and the rotating frame and the Support frames are kept aligned exactly parallel to each other.

A holder 50 for one end of a tension spring 52 is attached to the base plate 18 of the support frame and to the lever arm 20 formed by this base plate. The other end of this tension spring is anchored to the lever arm 24 of the rotating frame 12, so that a tensile force is permanently exerted which tends to pull the lever arms 20 and 24 together and the rotating frame 12 clockwise relative to the support frame 10 to pivot. However, the linear drive 22 is self-holding at least in the direction in which its length shortens, so that the torque caused by the tension spring 52 does not lead to an actual pivoting of the rotating frame 12. However, the elastic preload caused by the spring 52 results in any bearing play in the bearing formed by the control cams 34, 36 and the feeler rollers 38 as well as any drive play in the linear drive 22 and its articulated connections to the lever arms 20, 24 being eliminated.

During operation of the device, to which the rotating frame construction described here belongs, the lateral position of the material web is detected with the aid of a sensor, and the linear drive 22 is controlled via a controller so that the position of the material web is adjusted to a target value. In this control game, the linear drive 22 is alternately retracted and extended in order to pivot the rotating frame sometimes in one direction and sometimes in the other direction. The tension spring 52 ensures that no hysteresis occurs in this control game, since all components of the system in which a certain amount of play can occur are always held by the spring at the same limit of the range of motion made possible by this game.

In Fig. 3 The rotating frame construction is shown in a front view. A bearing plate 54 is welded onto the base plate 18 of the support frame 10, on which the feeler rollers 34, 36 are mounted. The floor plans of the base plate 18 and the bearing plate 54 are in Figures 5 and 6 shown separately. In Fig. 6 Bearing holes or bearing axes 56 for the feeler rollers 38, 38 can also be seen. In Fig. 5 The positions of these bearing axes are shown in dashed lines. The base plate 18 has recesses 58, 60 in which the ends of the bearing axles are received.

The brackets 40 for the support rollers 42 are also welded onto the bearing plate 54. Accurate positioning and secure fixation of the bracket 40 is achieved achieved in that these brackets have pins, not shown, on their edge facing the bearing plate 54, which engage in corresponding pin holes in the bearing plate 54.

Fig. 7 shows the complete support frame in a front view

The trapezoidal wall element 32 in plan, which forms the slots 44 for the support rollers 42, is in Fig. 3 to recognize and again separately in Fig. 8 shown. This wall element also has projecting pins 62 on its upper edge, which engage in corresponding pin holes (not shown) in the bolt 28.

Fig. 9 shows a front view of the wall element 46, which forms the slots 48 for the two remaining support rollers 42. This wall element also has pins 64 on its upper edge, which engage in pin holes in the bolt 28.

In Fig. 3 the wall element 46 is largely covered by the wall element 32 in front of it, so that only retaining webs 66 projecting downwards remain visible ( Fig. 9 ). These holding webs have pins 68 at their free lower ends, which engage in corresponding pin holes 70 in the cam plate 30, which are in Fig. 10 shown separately in the floor plan. The cam plate 30 is welded to the pins 68 and is thus fixed in its position in the rotating frame 12. For additional stabilization, the cam plate 30 has extensions 72 at both ends, which, as in Fig. 3 can be seen, engage positively in corresponding recesses in side walls 74 of the housing 26. In Fig. 10 The contours of the control curves 34 and 36 can also be seen more clearly.

In Fig. 4 The rotating frame construction is shown in a side view. Only the base plate 18 of the support frame can be seen here. The side walls 74 of the housing 26 of the rotating frame form bearing extensions 76 for the inlet roller 14 at both ends and the outlet roller 16 is extended. These bearing extensions can have a different shape depending on the desired threading of the material web. Fig. 4 shows the configuration for a reverse U-threading. In this configuration, the total height of the rotating frame construction is only slightly larger than the diameter of the inlet and outlet rollers 14, 16. In addition, in Fig. 4 one of the extensions 72 of the cam plate can be seen, which passes through the side wall 74.

Claims (14)

1. A rotary frame construction for web transport control devices, the rotary frame construction comprising a carrier frame (10) and a rotary frame (12) which extends in parallel with the carrier frame and carries an input roller (14) and an output roller (16) for a web to be controlled and is pivotably mounted on the carrier frame (10) by means of a bearing, the bearing having a virtual rotation center (P) that is defined by control surfaces (34, 36) of one (12) of the carrier frame and the rotary frame, the control surfaces being scanned by cam followers (38) on the other (10) of the frames, the frames being held in parallel alignment by means of support rollers (42) on one (10) of the frames and associated run surfaces on the other frame, the frames being connected with one another so as to be pivotable by means of a drive system (22), characterized in that the control surfaces (34, 36) are constituted by three control curves that are formed at the outer edges of a cam plate (30) that is rigidly held on one (12) of the frames, two (34) of the control curves being located on one side of the cam plate and the third (36) on the opposite side of the cam plate, and the other (10) of the frames has three cam followers (38) that are respectively associated with one of the control curves.
2. The rotary frame construction according to claim 1, wherein the cam plate (30) forms part of the rotary frame (12) and is enclosed by parts (40) of the carrier frame (10) which carries the cam followers that are preferably configured as follower rolls (38).
3. The rotary frame construction according to claim 2, wherein the carrier frame (10) has a base plate (18) that extends in parallel with the cam plate (30) and on which bearings for the follower rolls (38) are arranged such that the axes of rotation of the follower rolls are orthogonal to the base plate.
4. The rotary frame construction according to claim 3, wherein a support plate (54) carrying bearing axles (56) for the follower rolls (38) is mounted on the base plate (18) so as to rest flat on the base plate.
5. The rotary frame construction according to claim 3 or 4, wherein brackets (40) in which the support rollers (42) are rotatably supported are arranged upright on one of the base plate (18) and the support plate (54).
6. The rotary frame construction according to any of the claims 2 to 5, wherein the rotary frame (12) has two parallel side walls (74) with projecting bearing brackets (76) for the input roller (14) and the output roller (16) as well as a plate-shaped cross-bar (28) that connects the side walls (74) and on which the cam plate (30) is supported via studs (66).
7. The rotary frame construction according to any of the claims 1 to 6, wherein each of the support rollers (42) is accommodated in a slot (44, 48) that is formed in the other (12) of the frames and has parallel edges that form the run surfaces.
8. The rotary frame construction according to claim 7, comprising at least one wall member (32, 46) that is trapezoidal in plan view and has legs that extend tangentially with respect to a circle around the virtual rotation center (P), the slots (44, 48) being formed in the legs of this wall member.
9. The rotary frame construction according to claim 8, comprising two trapezoidal wall members (32, 46) that are arranged such that the base lines of the trapezoids are parallel to one another and the symmetrically arranged legs of the two wall members form different angles with the base line, the rotary frame construction comprising a total of four support rollers (42) engaging in a respective one of the slots (44, 48) of the wall members.
10. The rotary frame construction according to claim 9, wherein one (46) of the wall members forms the studs (66) for holding the cam plate (30).
11. The rotary frame construction according to claim 5 or any of the claims 8 to 10, wherein the brackets (40) and/or the wall members (32, 46) have pegs (62, 64, 66) that engage in corresponding peg holes (70) of the base plate (18), the support plate (54), the cross-bar (28) and the cam plate (30), respectively.
12. The rotary frame construction according to claim 6, wherein the cam plate (30) has projections (72) that are in form-fitting engagement with recesses in the side walls (74) of the rotary frame (12).
13. The rotary frame construction according to any of the preceding claims, wherein the drive system (22) is self-arresting in at least one direction, and the frames (10, 12) are elastically biased against one another in the rotary direction in which the drive system is self-arresting.
14. The rotary frame construction according to claim 13, wherein the drive system (22) is a linear drive that is connected to a lever (20, 24) of the carrier frame (10) and the rotary frame (12), respectively, by articulated joints, and one of a compression spring and a tension spring (52) is held under tension between these levers.

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