EP4029817A1 - Rotary frame structure for web poition control devices - Google Patents

Abstract

1. Rotating frame construction for web guiding devices, with a supporting frame (10) and a rotating frame (12) parallel thereto, which carries an infeed roller (14) and an outfeed roller (16) for a web to be controlled and pivotable by a bearing on the supporting frame (10) is held, the bearing having a virtual pivot point (P) defined by control surfaces (34, 36 of one frame (12) scanned by cam followers (38) of the other frame (10), and wherein the frames are Support rollers (42) of one (10) of the frames and associated running surfaces of the other frame are held in parallel alignment and are pivotably connected to one another by a drive (22), characterized in that the control surfaces are three control cams (34, 36). , which are formed on the outer edges of a cam plate (30) rigidly held to one (12) of the frames and of which two (34) are on one side of the cam plate and the third (36) on the opposite underlying side of the cam plate, and that the other of the frames (10) has exactly three cam followers (38), each associated with one of the cams.

Description

The invention relates to a rotating frame construction for web guiding devices, with a supporting frame and a rotating frame parallel thereto, which carries an infeed roller and an outfeed roller for a web to be controlled and is held pivotably on the supporting frame by a bearing, the bearing having a virtual pivot point which is control surfaces of one frame being sensed by cam followers of the other frame, the frames being held in parallel alignment by idler rollers of one of the frames and associated running surfaces of the other frame and being pivotally interconnected by a drive.

When processing running webs of material, for example in rotary printing presses, it is generally necessary to control or regulate web travel so that the web is prevented from migrating 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 90°, for example, at the infeed roller and at the outfeed roller. If the direction of travel deviates from the desired direction, the rotary frame, which carries the infeed roller and the outfeed roller, is pivoted relative to the support frame in such a way that the infeed and outfeed rollers assume a different orientation and direct the web back in the desired direction.

In most conventional rotating frame designs, the infeed roller and the outfeed roller are arranged with parallel axes in a plane parallel to the rotating frame, but offset from the plane of the rotating frame enough to allow the rollers to rotate freely. The rotary frame and the support frame are designed to be approximately congruent and are also arranged in planes that are offset from one another, so that they can be pivoted relative to one another. Overall, the rotating frame construction thus has a three-layer structure.

The pivot about which the pivot frame pivots relative to the support frame should ideally be in the center of the incoming web so that the pivot axis is perpendicular to the plane of the pivot frame and tangential to the outer crest of the infeed roll. In this way it can be achieved that when the rotating frame is pivoted, the incoming web remains practically stationary, while the outgoing web is displaced in the desired direction.

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

A rotary frame construction of the type mentioned above is 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 which roll on the walls both on the inside and outside of the curve, so that the degrees of freedom of movement in the plane parallel to the frames are reduced to one degree of freedom of rotation. The running surfaces for the support rollers are formed by bearing plates running parallel to the frame, 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 planes of the frames and also do not tilt relative to one another about an axis running parallel to the plane of the frames can become.

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 associated with one of the cams.

With 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, act on the 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 rotary frame is made possible.

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

Advantageous configurations are specified in the dependent claims.

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 rotary frame, which surrounds the supporting frame with its outer edge, then has a horizontal bar on which the cam plate is arranged in such a way that it is in turn surrounded by the parts of the supporting frame on which the cam followers are formed.

In an advantageous embodiment, the support rollers, which ensure the parallel alignment of the frames and which are arranged, for example, on the support frame, are each received with little play in a slot formed in the other frame (the rotating frame) and the parallel edges of which are the running surfaces form for the support roller. In this way, a relative movement in the direction perpendicular to the planes of the frame can already be prevented with a single support roller, since this can only move in the slot parallel to the plane of the frame. A small amount of play between the support roller and the edges of the slot enables a low-friction rolling movement at either 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 an allowable tolerance for relative movement of the frames in the direction perpendicular to the planes of the frames.

This mechanism for parallel alignment of the frames can also be used to advantage independently of the features of claim 1 described above. A rotary frame construction is thus also disclosed according to the preamble of claim 1, which is characterized in that each of the support rollers is accommodated 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 bolt running parallel to the plane of the rotating frame, the slots for the support rollers can be formed in connecting components which connect the cam plate to the bolt. In this way, a particularly simple construction 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 planes). Brackets can also be mounted on this plate, on the vertical legs of which the support rollers are then mounted with a horizontal axis of rotation, which engage in the slots of the connecting component.

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

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

In the following an embodiment is explained in more detail with reference to the drawings.

Show it:

1

a schematic representation of a rotary frame construction in plan view;

2

the rotating frame construction with a slightly pivoted rotating frame;

3

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

4

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

figure 5

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

6

a bearing plate of the support frame in plan view;

7

a front view of the support frame;

Figures 8 and 9

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

10

a floor plan of the curve plate.

In 1 shows a top view of a rotary frame construction with a support frame 10 and a rotary frame 12 which is pivotable about a virtual pivot point P relative to the support frame. 2 shows the rotating frame construction with a slightly pivoted rotating frame. For better differentiation, all of the (stationary) parts belonging to the support frame 10 are shown in thicker 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 rotary frame 12, over which a material web (not shown) is guided, the web run of which is to be controlled with the aid of the rotary frame construction. For example, the web can be reverse U-threaded upwards (in 1 towards the viewer) to the infeed roller 14 where it is deflected to the horizontal so that it runs to the outfeed 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 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 1 the base plate 18 forms a lever arm 20 which protrudes beyond the lateral edge of the rotary frame 12 and is connected via an articulated linear drive 22 to a bracket or a lever arm 24 of the rotary frame. When the linear actuator 22 pulls the lever arms 20 and 24 together, the pivot frame 12 pivots about the pivot point P going vertical pivot axis, as in 2 is shown. This pivot axis forms a tangent to the infeed roller 14, so that the infeed roller and thus the incoming material web does not perform any transverse movement when the rotary frame 12 is rotated, while the outfeed roller 16 and the outgoing material web experience a position shift in the transverse direction.

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

The edge of the cam plate 30 forms on the in 1 lower side two arcuate control cams 34 and on the upper side another circular control curve 36. The control curves 34 and 36 are centered on the virtual pivot point P. In order to clarify the curvature of these cams 34, 36, 1 extended circular arc pieces (solid lines) shown. Each cam 34, 36 is associated with a feeler roller 38 which is rotatably mounted on the support frame 10 about a vertical axis. The three feeler rollers 38 rest practically without play on the edge of the cam plate 30, so that this cam plate and thus the entire rotating frame 12 can only perform a circular movement about 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 ( 8 ) was added, which run horizontally in the legs of the trapezoidal wall element 32. These legs of the wall element 32 are angled in such a way that they are tangential to an arc of a circle 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 rotary frame is now pivoted, there is a relative movement between the support roller and the slot, and the support roller rolls off the upper edge of the slot.

In the event an upward force is applied to the pivot frame 12, the lower edges of the slots 44 will be drawn against the idler rollers 42 and upon pivotal movement, the idler rollers will 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 so small that the possible vertical movement of the wall element 32 relative to the support frame due to this play remains within the permissible tolerance limits.

In the housing 26 of the rotary frame 12, another wall element 46 with a trapezoidal plan view is accommodated, which is held firmly on the underside of the bolt 28, and in the angled legs of which horizontal slots 48 are also formed ( 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 in such a way that they run tangentially to an arc of a circle 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 vertical movement of the rotating frame relative to the supporting frame, and the rotating frame and the Support frames are kept exactly parallel to each other.

A holder 50 for one end of a tension spring 52 is fastened 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 rotate the rotating frame 12 clockwise relative to the support frame 10 to pivot. However, the linear drive 22 is self-retaining 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 rotary frame 12 . However, the elastic preload caused by the spring 52 means that any bearing play in the bearing formed by the cams 34, 36 and the feeler rollers 38 and any drive play in the linear drive 22 and its articulated connections to the lever arms 20, 24 is eliminated.

During operation of the device, to which the rotary frame construction described here belongs, the lateral position of the material web is detected using a sensor, and the linear drive 22 is controlled via a controller in such a way that the position of the material web is adjusted to a setpoint. In this control game, the linear drive 22 is alternately retracted and extended in order to pivot the rotary frame in one direction and in the other direction. The tension spring 52 ensures that no hysteresis occurs in this control game, since all components of the system where 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 play.

In 3 the rotating frame construction is shown in a front view. On the base plate 18 of the support frame 10, a bearing plate 54 is welded, on which the feeler rollers 34, 36 are mounted. The outlines of the base plate 18 and the bearing plate 54 are in Figures 5 and 6 shown separately. In 6 bearing holes or bearing axles 56 for the feeler rollers 38, 38 can also be seen. In figure 5 the positions of these bearing axes are drawn 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 . A precise positioning and secure fixation of the bracket 40 is achieved in that these brackets have pegs, not shown, on their edge facing the bearing plate 54, which engage in corresponding peg holes of the bearing plate 54.

7 shows the complete support frame in a front view

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

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 pegs 64 on its upper edge, which engage in peg holes of the bolt 28 .

In 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 ( 9 ). At their free lower ends, these holding webs have pins 68 which engage in corresponding pin holes 70 of the cam plate 30, which 10 shown separately in the floor plan. The cam plate 30 is welded to the pins 68 and is thus fixed in position in the rotating frame 12 . For additional stabilization, the cam plate 30 has extensions 72 at both ends, which, as shown in 3 can be seen, positively engage in corresponding recesses in side walls 74 of the housing 26. In 10 the contours of the cams 34 and 36 can also be seen more clearly.

In 4 the rotating frame construction is shown in a side view. Only the base plate 18 of the supporting frame can be seen here. The side walls 74 of the housing 26 of the rotary frame are at both ends to bearing extensions 76 for the infeed roller 14 and the outfeed roller 16 lengthened. Depending on the desired threading of the material web, these bearing extensions can have a different shape. 4 shows the configuration for an inverted U-thread. In this configuration, the overall height of the rotating frame construction is only slightly larger than the diameter of the infeed and outfeed rollers 14, 16. In addition, in 4 to recognize one of the extensions 72 of the cam plate, which passes through the side wall 74.

Claims (14)

Rotating frame construction for web guiding devices, with a supporting frame (10) and a rotating frame (12) parallel thereto, which carries an infeed roller (14) and an outfeed roller (16) for a web to be controlled and is held pivotably on the supporting frame (10) by a bearing , wherein the bearing has a virtual pivot point (P) defined by control surfaces (34, 36 of one frame (12) which are traced by cam followers (38) of the other frame (10), and wherein the frames are supported by idlers ( 42) of one (10) of the frames and associated running surfaces of the other frame are held in parallel alignment and are pivotally connected to one another by a drive (22), characterized in that the control surfaces are control cams (34, 36) which are attached to the outer edges of a cam plate (30) rigidly supported on one (12) of the frames, two (34) being on one side of the cam plate and the third (36) on the opposite the sides of the cam plate, and that the other of the frames (10) has three cam followers (38) each associated with one of the cams. A pivoting frame construction according to claim 1, wherein the cam plate (30) is part of the pivoting frame (12) and is surrounded by parts (40) of the support frame (10) which carries the cam followers, which are preferably in the form of follower rollers (38). Rotating frame construction according to claim 2, wherein the supporting frame (10) has a base plate (18) running parallel to the cam plate (30), on which bearings for the feeler rollers (38) are arranged in such a way that the axes of rotation of the feeler rollers extend perpendicularly to the base plate . Rotating frame construction according to Claim 3, in which a flat bearing plate (54) is fastened to the base plate (18) and carries bearing axles (56) for the feeler rollers (38). Rotating frame construction according to claim 3 or 4, in which on the base plate (18) or the bearing plate (54) there are arranged upright brackets (40) on which the support rollers (42) are mounted. Rotating frame construction according to one of Claims 2 to 5, in which the rotating frame (12) has two parallel side walls (74) with bearing projections (76) for the infeed rollers (14) and the outfeed rollers (16) and a plate-shaped bolt (28) connecting the side walls , on which the cam plate (30) is held by holding webs (66). A rotating frame construction as claimed in any one of Claims 1 to 6, in which each of the support rollers (42) is received in a slot (44, 48) formed in the other frame (12), the parallel edges of which form the running surfaces. Rotating frame construction according to claim 7, with at least one wall element (32, 46) which is trapezoidal in plan and whose legs run tangentially to a circle around the virtual pivot point (P), in which the slots (44, 48) are formed in the legs of this wall element. Rotating frame construction according to Claim 8, with two trapezoidal wall elements (32, 46) which are arranged in such a way that the bases of the trapezoids run parallel to one another and the symmetrically arranged legs of each wall element form a different angle with the base, and with a total of four support rollers ( 42) which each engage in one of the slots (44, 48) of the wall elements. A pivoting frame construction as claimed in claim 9, wherein one (46) of the wall members forms the attachment webs (66) for the cam plate (30). A pivoting frame construction according to claim 5 or any one of claims 8 to 10, wherein the brackets (40) and/or the or each wall member (32, 46) have pegs (62, 64, 66) which engage in corresponding peg holes (70) in the base plate (18) or the bearing plate (54) or the latch (28) or the cam plate (30). Revolving frame construction according to Claim 6, in which the cam plate (30) has extensions (72) which positively engage in recesses in the side walls (74) of the revolving frame (12). A pivoting frame construction as claimed in any preceding claim, wherein the drive (22) is self-retaining in at least one direction and the frames (10,12) are resiliently biased towards one another in the direction of rotation in which the drive is self-retaining. Rotating frame construction according to Claim 13, in which the drive (22) is a linear drive which is articulated to one lever arm (20, 24) of the support frame (10) and one of the rotating frame (12), and in which a compression spring or Tension spring (52) is tensioned.

Images