EP3397492B1 - Pressure plate clamping rail - Google Patents

Description

The invention relates to a device for clamping flexible printing plates on the plate cylinder of a rotary printing press according to the preamble of claim 1.

Through the DE-OS 26 26 503 a printing plate clamping device has become known in which a printing plate end is clamped between parallel clamping surfaces of a plate support fixed to the housing and a terminal strip guided perpendicular thereto. A movement of the terminal strip takes place via several toggle lever mechanisms arranged axially parallel to which an eccentric acts in each case in the area of the toggle joint. The eccentrics are arranged on a common shaft and are actuated together when the shaft is rotated. The toggle lever mechanisms are moved beyond a stretched position into a stable top dead center position against a stop designed as a second eccentric. To move the toggle joints out of their stable top dead center position, the second eccentrics are pivoted against the direction of action of the first eccentrics by means of a second common shaft.

Disadvantageous in the DE-OS 26 26 503 The devices shown are that the pressure plate clamping device must be operated by hand or with tools, which leads to the extension of the set-up times. In addition, automatic actuation is not possible.

Out DE 42 15 612 C1 a clamping device for a printing machine for fastening a printing plate on a printing cylinder between a clamping strip and a clamping strip is known. A clamping device is made available in which a defined clamping force can be achieved for clamping the printing plate and which is well suited for automatic clamping of the printing plate is in that the terminal strip can be moved into the clamping position by means of a predetermined actuating force translated via several toggle lever mechanisms.

From the DE 37 31 039 A1 a device for clamping flexible printing plates on the plate cylinder of a rotary printing press is known. In this device, several toggle linkages are arranged axially parallel to actuate a terminal strip. The toggle linkage is by means of several springs brought into an extended position and by means of a pneumatically operated device from this extended position.

Furthermore, plate clamping rails and coating form carrier clamping rails are also used in sheet-fed offset printing machines for the automated tensioning and clamping of printing plates or coating form carriers DE 10 2007 002 785 B4 and the DE 20 2007 002 299 U1 known, which work with at least one hose segment each, which are arranged on each side of a toggle lever drive generating the clamping movement of the slide rails.

The invention is based on the object of creating a clamping device for flexible printing plates on the plate cylinder of a rotary printing press which enables the clamping device to be actuated without tools.

According to the invention, the object is achieved by the characterizing part of patent claim 1.

The advantages that can be achieved with the invention are in particular that tools can be dispensed with when converting the printing press. Consequently, no points of engagement for the tools need to be provided on the plate cylinder. In particular, the device according to the invention makes it possible to provide a remote or foot control, so that an operator has his hands free when converting the machine.

The pressure hose no longer presses directly on the knee lever to open the splint. The force of the pressure hose is centrally directed directly to the spring via pressure pieces. The pressure pieces run through the lever segments, which are also guided axially in their position. This gives the force of the pressure hose on the compression spring without loss of leverage. This enables an efficient design.

The device is suitable for clamping different sheet thicknesses / coating form carrier thicknesses. In the following only printing plates are mentioned. The clamping force changes only slightly depending on the material thickness to be clamped. Settling behavior or wear of the components to generate the clamping force is automatically compensated for and only leads to negligible changes in the clamping force, in particular only to only slight increases in the clamping force.

Due to the concept, the components involved in the clamping process can mainly be designed with standard tolerance values. The clamping force can also be individually adjusted in the simplest way, depending on the structural design.

If no printing plate is clamped in the plate clamping rail, the system can still close completely, depending on the design, so that the clamping rail can remain in the printing machine even without the plate clamped, as the mechanism is pretensioned and nothing can move uncontrollably when it is moved. Alternatively, a stop for fixing the rail elements can be provided for the basic position.

The closing process does not make any noise. The toggle lever drive does not reverse, so that no reversal of the direction of force can occur within the movable lower rail. There is also no need to compensate for a loss of clamping, because the toggle lever drive shortens again after passing through the top dead center and thus removes clamping force.

Changes in force slowly build up and down. That protects the construction. The lower rail is moved via a knee lever. Depending on the position of the toggle lever, the plate clamping rail is closed (the plate is clamped) or the plate clamping rail is open.

• Eine Feder drückt seitlich, gegen das Kniehebel-Gelenk (dies nimmt hierbei eine konvexe Stellung zur Feder ein), dadurch werden die Kniehebelendpunkte, welche auf der einen Seite am Gehäuse und auf der anderen Seite an der beweglichen Unterschiene befestigt sind, auseinander gedrückt. Die Schiene ist geschlossen und die Platte ist geklemmt.
• Zum Öffnen der Plattenspannschiene wird z.B. ein Druckschlauch mit Druckluft beaufschlagt. Der Druckschlauch ist konkav zum Kniehebel auf der Gegenseite zur Feder positioniert. Der Druckschlauch arbeitet gegen die Federkraft, die Kniehebelenden verkürzen sich und die Unterschiene bewegt sich nach unten. Ein integrierter Anschlag lässt den Öffnungsweg begrenzen. An Stelle eines Druckschlauches kann auch eine andere Kraftquelle genutzt werden.
• Wird der Druckschlauch entlüftet, erzeugt die anstehende Federkraft wieder einen Kraftüberschuss und die Plattenspannschiene schließt sich.

The positions of the knee lever are reached as follows:

• A spring pushes laterally against the toggle joint (this assumes a convex position to the spring), thereby the toggle end points, which are on one side on the housing and on the other side on the movable Lower rails are attached, pressed apart. The rail is closed and the plate is clamped.
• To open the plate clamping rail, compressed air is applied to a pressure hose, for example. The pressure hose is positioned concave to the knee lever on the opposite side to the spring. The pressure hose works against the spring force, the knee lever ends shorten and the lower rail moves downwards. An integrated stop can limit the opening path. Instead of a pressure hose, another power source can also be used.
• If the pressure hose is vented, the existing spring force generates an excess of force and the panel clamping rail closes.

The knee lever never overturns. The clamping force results from the triangle of forces which the spring exerts on the lower rail in the closing direction by means of the angular position of the toggle lever.

If the material of the pressure plate to be clamped becomes stronger, the triangle of forces worsens in the sense that less force is generated to close the plate clamping rail, but the spring force increases because the spring is more pretensioned in this position. In the usual plate thickness range of 0.2 to 0.4 mm and with coating form carrier thicknesses of up to approx. 2 mm (with coating form carriers), the resulting clamping forces are almost identical, depending on the geometric design.

The clamping force can be adjusted by adjusting the spring position to the knee lever. Change e.g. Clamping lever lengths or positions of clamping lever end points due to wear or the utilization of manufacturing tolerances of the components involved, the resulting behavior is ultimately the same as when the force is built up to clamp different material thicknesses. The influence on the clamping force is slight or at most leads to an increase in the clamping force, since the toggle lever is stretched further due to wear.

Depending on the design, the lower rail can theoretically be pressed into the upper rail, so that the system also jams, if no plate is clamped. Toggle levers, springs and bottom rails can be divided into different segments across the format width. In this way, manufacturing tolerances of the components can be better compensated for. A clamping force that is as uniform as possible over the entire clamping area is achieved.

Through improvement measures, the influence of transverse forces is avoided, which in the prior art according to Figure 1 and when using a pressure hose in direct contact with the toggle levers. Lateral forces pull the two toggle lever segments apart at their common pivot point. Manufacturing tolerances are pushed into their end positions, which reduce the opening gap, but which have a negative impact on the accuracy and reproducibility of the clamping process before a subsequent clamping process.

In the solution according to the invention, however, transverse forces no longer occur. Therefore, the lower clamping rail can easily and with little force e.g. be pressed down in the direction of the "Rail opening" function by means of a tension or compression spring, a lever, etc. Thus, the toggle lever package always remains under sufficient pressure to avoid play and is practically constantly internally in a play-free network. The toggle lever segments lie freely in the plate clamping rail and no connecting elements to the lower clamping rail, to the housing or between the toggle lever segments are necessary.

The clamping system is therefore inexpensive and easy to assemble.

The pressure piece is made in two parts. A second, smaller pressure piece is designed to be axially displaceable in the first pressure piece. This means that individual springs can be pressed over the thread in the first pressure piece using a screw, supported on the rail body (assembly / disassembly / repair) without the pressure hose being inflated.

The second smaller, axially displaceable pressure piece remains in its position and therefore does not cause the rail to open. If at least two pressure pieces are passed through a toggle lever package, this is axially displaceable necessary, otherwise the system will be damaged. If this axial displaceability were not given, the second spring would work against the first spring via the toggle lever assembly and lead to tension forces and damage within the rail.

In terms of design, a toggle lever package contains three springs. Several toggle lever packages are used within a plate clamping rail.

Figur 1

einen Schnitt durch eine bekannte Plattenbefestigungseinrichtung,

Figur 2

eine Ausführungsform einer Plattenbefestigungseinrichtung,

Fig. 2a/2b

zwei Kraftschemata zu einer Plattenbefestigungseinrichtung,

Figur 3

eine Detailierung einer Plattenbefestigungseinrichtung,

Figur 4

eine Teilansicht der die Klemmung bewirkenden Kniehebelschienen der Plattenbefestigungseinrichtung,

Figur 5

eine Detailansicht aus der Plattenbefestigungseinrichtung und

Figur 6

eine Teilansicht der Plattenbefestigungseinrichtung im Teilschnitt.

In addition to a solution from the prior art, two exemplary embodiments of the invention are illustrated below with reference to drawings and explained in more detail in a description. It shows

Figure 1

a section through a known plate fastening device,

Figure 2

an embodiment of a plate fastening device,

Figures 2a / 2b

two force schemes for a plate fastening device,

Figure 3

a detailing of a panel fastening device,

Figure 4

a partial view of the clamping-effecting toggle lever rails of the plate fastening device,

Figure 5

a detailed view of the plate fastening device and

Figure 6

a partial view of the plate fastening device in partial section.

Figure 1 shows a device according to the prior art. A plate cylinder 1 is provided with a cylinder channel 2 for receiving two plate clamping rails 3, only one of which is shown here. A plate clamping rail 3 is provided on the bottom 5 with a rail body 4 extending over the length of the plate cylinder 1. The rail body 4 can be displaced in the cylinder channel 2 in the direction of a left and a right side delimitation 6, 7. In the axially parallel direction, several bearing points 8 are arranged for pivotably receiving the respective lower end 11 of lower rail couplings 9 of a toggle lever drive, the upper end 12 of which are articulated to a then lower end 13 of upper rail couplers 10, with upper ends 14 of the upper rail couplers 10 in Bearing points 15 are pivotably mounted. The camp points 15 are arranged on an upper rail 16 which can be pivoted relative to the rail body 4 for clamping the pressure plates. This has a T-shape and is arranged with a rounded foot designed as a bearing 17 in a recess 18 of the rail body 4 assigned to the left side boundary 6. The left end of the upper rail 16 forms the clamping strip 19 and works against a plate support 20 on the upper side of the rail body 4 so that the end of a pressure plate 21 is clamped there. A guide rail 22, which supports the upper rail 16 during the clamping movement, is attached to an upper side on the right-hand side boundary 7 of the rail body 4.

Under the guide rail 22, between a wall of the rail body 4, the couplings 9 and 10, a pressure space 23 extending over the length of the cylinder is formed, in which one or more inflatable, elastic hoses 24 are received. In the left side delimitation 6 of the rail body 4, a compression spring 26 acting on the latter is arranged in a recess 25 for each toggle lever drive 9, 10. The compression springs 26 are supported on the bottom of the recesses 25 and press the toggle lever drive 9, 10 at least into an extended position. The hoses 24 are arranged to counteract the compression springs 26 and deflect the toggle linkage 9, 10 out of the extended position in order to open the upper rail 16 to release the disk clamp relative to the disk support 20.

On the left wall of the cylinder channel 2, several recesses 27 are provided in the rail body 4, in each of which an inflatable, elastic bellows 28 is mounted and is supported on the channel wall. On the opposite channel wall, a plurality of compression springs 29 are arranged in each case in a recess 30 of the rail body 4 in order to displace the rail body 4. These compression springs 29 act horizontally between the rail body 4 and the channel side wall against the force of the bellows 28 to move the rail body 4 approximately in a circumferential direction to the plate cylinder 1 in the cylinder channel 2.

In Figure 2 the basic form according to the invention of a novel plate clamping device 3 is shown which contains a printing plate clamp and for which the im The following general prerequisites for a proper clamping of the printing plate apply.

A plate clamping rail that contains a printing plate clamping device must be suitable for clamping printing plates or coating form carriers with different plate thicknesses. In the following only printing plates are mentioned. The clamping force should change as little as possible depending on the material thickness to be clamped. It should be noted, however, that mainly less compressible materials such as aluminum plates, plastic clichés or high-strength rubber or printing blankets should be provided for clamping in such printing plate clamping rails.

Settling behavior or wear of the components to generate the clamping force should be compensated automatically and should only lead to negligible changes in clamping force that do not impair the clamping effect.

Based on the concept according to the invention, the components involved in the clamping process can mainly be designed with standard tolerance values.

If necessary, the clamping force itself or its basic setting can also be made individually adjustable in a simple manner by means of an appropriate structural design.

The functional sequence of the clamping process itself is controlled in a manner known per se via one or more pneumatic valves.

If no printing plate is clamped, the system still closes completely, depending on the design of the toggle lever drive contained here, so that the plate clamping rail can remain in the printing machine even without the printing plate clamped. The mechanism is preloaded and cannot move uncontrollably when the plate cylinder is moved.

The pretensioning of the non-tensioned plate clamping rail system can also be ensured in a simple manner by means of a system-internal stop. Such a stop directly on the toggle lever elements or with the interposition of the pressure hose or

The closing process does not make any noise. The toggle lever drive used is designed in such a way that when the pressure plate is clamped it does not overturn over its dead center, so that there can be no reversal of the direction of force with an undesired reduction in the clamping force on the movable lower rail.

Furthermore, compared to systems that push the dead center of the toggle lever drive into an end position at a stop, no loss of clamping force has to be compensated for. This is necessary because the effective length of the toggle lever drive is shortened again after passing through the top dead center and the clamping force is thereby reduced. Furthermore, changes in force build up and decrease slowly and protect the moving parts and bearings of the device.

In Figure 2 it is shown that a toggle lever drive with a lower link 39 and an upper link 40, which are connected to one another by a toggle joint 42, is used for clamping the pressure plate. The toggle lever drive (elements 39, 40, 42) is supported in a rail body 41 and is arranged between a lower rail 43, which is vertically movable for the purpose of clamping the pressure plate, and the rail body 41. The toggle joint 42 connects the lower and the upper link 39, 40. The upper link 40 is supported upwards against the vertically movable lower rail 43, which by the pivoting movement of the toggle drive (elements 39, 40, 42) linearly towards an upper rail 44 is moved. The upper rail 44 is a fixed or rigidly mounted part on the rail body 41. Depending on the current position (stretched or bent) the toggle lever drive (elements 39, 40, 42) is in, the clamping function of the plate clamping rail 3 is closed and a pressure plate 45 is clamped between the lower rail 43 and the upper rail 44 or the clamping function of the plate clamping rail 3 of the upper 44 and lower rail 43 is open.

Furthermore, a sleeve-shaped pressure piece 46 is arranged in the rail body 41 so as to be longitudinally movable, which is loaded by a compression spring 47 and is assigned to the toggle joint 42 with an active surface opposite the compression spring 47. The compression spring 47 is supported on the rail body 41 in an annular groove 47a serving as a spring guide.

If, including the annular groove 47a, from the bottom areas 48 each serving to guide a compression spring 47, an as e.g. is formed via a thread in the rail body 41 adjustable insert element, each of these elements formed in this way can be used in the area of an annular groove 47a for presetting or readjustment of the spring force of the compression spring 47 acting there in relation to the toggle lever drive 39, 40, 42.

The rail body 41 is closed by means of a cover 51 which thus forms a pressure space 49 opposite the toggle lever drive 39, 40, 42. Furthermore, the rail body 41 and cover 51 in the upper space form a parallel guide for the vertical movement of the lower rail 43.

A pressure hose 50 is arranged in the pressure chamber 49 and is coupled to at least one pneumatic line via a valve control. The pressure hose 50 can be supplied with compressed air by means of the valve control, so that the pressure hose 50 is inflated and, while being supported on the cover 51, exerts a force against the toggle lever drive 39, 40, 42. The force exerted by the pressure hose 51 acts on the toggle lever drive against the force of the spring 47.

• Das im Schienenkörper 41 längsbeweglich angeordnete, hülsenförmige Druckstück 46 wird durch die Druckfeder 47 belastet, welche abgestützt in der Ringnut 47a am Schienenkörper 41 angeordnet ist und im Bereich des Kniehebel-Gelenks 42 gegen den oberen 40 und den unteren Lenker 39 (konvexe Grundstellung zur Druckfeder 47) drückt. Die oberen und unteren Kniehebelendpunkte 39a, 40a, welche auf der unteren Seite am Schienenkörper 41 im Zylinderkanal 2 des Plattenzylinders 1 und auf der oberen Seite an der beweglichen Unterschiene 43 schwenkbar befestigt oder gelenkig abgestützt sind, werden so auseinander gedrückt. Der Klemmspalt der Plattenspannschiene 3 wird geschlossen, indem die Unterschiene 43 gegenüber dem Schienenkörper 41 nach oben bewegt wird, so dass die Druckplatte 45 zwischen der beweglichen Unterschiene 43 und der feststehenden Oberschiene 44 eingeklemmt wird. Die Klemmflächen an der Oberschiene 44 und der Unterschiene 43 sind zur verbesserten Kraftübertragung aufgeraut oder strukturiert.
• Zum Öffnen der Plattenspannschiene 3 wird z.B. ein Druckschlauch 50 mit Druckluft beaufschlagt. Der Druckschlauch 50 ist an der konkaven Seite des Kniehebeltriebs 39, 40, 42 auf der Gegenseite zu dem von der Druckfeder 47 belasteten Druckstück 46 positioniert. Der Druckschlauch 50 arbeitet bei Druckbeaufschlagung gegen die Federkraft der Druckfeder 47, so dass die Kniehebelenden 39a, 40a ihren Abstand verkürzend sich aufeinander zu bewegen und die Unterschiene 43 bewegt sich gegenüber dem Schienenkörper 41 linear nach unten und entfernt sich dabei von der Oberschiene 44. Mittels eines integrierten Anschlages, der auf die Lenker 39, 40 oder das Druckstück 46 wirken kann, lässt sich der Öffnungsweg des Kniehebeltriebs 39, 40, 42 begrenzen. An Stelle eines Druckschlauches 50 kann auch eine andere flexible Kraftquelle in Art eines pneumatischen Muskels genutzt werden.
• Wird der Druckschlauch 50 wieder entlüftet, kann die Federkraft aus der Druckfeder 47 den Kniehebeltrieb 39, 40, 42 wieder strecken und die Klemmfunktion der Plattenspannschiene 3 schließt sich erneut. Hierbei bewegt sich der Kniehebeltrieb 39, 40, 42 niemals über seinen Totpunkt und schlägt also nicht auf eine Lösestellung um. Dies kann durch einen Anschlag realisiert sein.

The positions of the toggle lever drive are reached as follows:

• The sleeve-shaped pressure piece 46, which is arranged longitudinally movable in the rail body 41, is loaded by the compression spring 47, which is supported in the annular groove 47a on the rail body 41 and in the area of the toggle joint 42 against the upper 40 and lower link 39 (convex basic position relative to the compression spring 47) presses. The upper and lower toggle lever end points 39a, 40a, which on the lower side on the rail body 41 in the cylinder channel 2 of the plate cylinder 1 and on the upper side on the movable Lower rail 43 are pivotally attached or supported in an articulated manner, are thus pressed apart. The clamping gap of the plate clamping rail 3 is closed in that the lower rail 43 is moved upwards relative to the rail body 41, so that the pressure plate 45 is clamped between the movable lower rail 43 and the fixed upper rail 44. The clamping surfaces on the upper rail 44 and the lower rail 43 are roughened or structured for improved power transmission.
• To open the plate clamping rail 3, compressed air is applied to, for example, a pressure hose 50. The pressure hose 50 is positioned on the concave side of the toggle lever drive 39, 40, 42 on the opposite side to the pressure piece 46 loaded by the pressure spring 47. When pressure is applied, the pressure hose 50 works against the spring force of the compression spring 47, so that the toggle lever ends 39a, 40a move towards one another, shortening their distance, and the lower rail 43 moves linearly downwards relative to the rail body 41 and moves away from the upper rail 44 An integrated stop, which can act on the link 39, 40 or the pressure piece 46, the opening travel of the toggle lever drive 39, 40, 42 can be limited. Instead of a pressure hose 50, another flexible power source in the form of a pneumatic muscle can also be used.
• If the pressure hose 50 is vented again, the spring force from the pressure spring 47 can stretch the toggle lever drive 39, 40, 42 again and the clamping function of the plate clamping rail 3 closes again. Here, the toggle lever drive 39, 40, 42 never moves above its dead center and therefore does not change to a release position. This can be achieved by a stop.

The clamping force of the plate clamping rail 3 can be derived from a force triangle, which results from the force K _F and the direction of force of the compression spring 47, the length and the angular position of the elements of the toggle lever drive 39, 40, 42 and the thickness of the respective pressure plate 45 to be clamped. A vertical force component is thus exerted as a clamping force K _K on the lower rail 43 in its closing direction against the upper rail 44.

This effect is in the Figures 2a and 2b shown schematically. Thus, a spring force F _F acting horizontally on a lower end of a link 40 becomes a clamping force F _K acting vertically on an upper end of the link 40, which varies according to the inclination of the upper link 40 due to the thickness of the pressure plate 45 to be clamped on the lower rail 43 trains.

Will according to Figure 2b If the material of the printing plate to be clamped is thicker, the effect of this triangle of forces consisting of K _F and K _K worsens in the sense that a lower resultant force for closing the clamping gap of the plate clamping rail 3 or for clamping a printing plate is generated. At the same time, however, there is a greater effective spring force, since the compression spring 47 is also more strongly pretensioned in this more strongly deflected position.

Plate thicknesses of 0.2 to 0.4 mm are usually used for offset printing plates and up to approx. 2 mm for coating form carriers. Depending on the geometric design, this results in an almost identical clamping force. The two following practical examples have been chosen arbitrarily to show that significant differences in thickness provoke comparatively small differences in clamping force in the panel clamping rail: - plate thickness 1.9 mm → Clamping force 1,151 N. - plate thickness 0.27 mm → Clamping force 1,310 N

If, for example, the length of the clamping lever or the length of the handlebars or the positions of the clamping lever end points should change in the arrangement shown due to wear or the utilization of manufacturing tolerances of the components involved, this has no effect on the clamping effect of the plate clamping rail 3, since such dimensional changes act like clamping of printing plates with different material thicknesses. The influence on the clamping force is small and, due to a slight stretching of the toggle lever system, tends to increase the force and thus in any case not deteriorate the function.

Depending on the design of the lever lengths of the links 39, 40, the toggle lever drive can theoretically be overpressed beyond its dead center position while the lower rail 39 is in contact with the upper rail 40 if no pressure plate 45 is provided in the clamping gap. The system of the plate clamping rail 3 is thus jammed and is automatically in a secured state even without being used for a printing process.

The toggle lever drive 39, 40, 42 and the compression springs 47 can be arranged several times next to one another over the format width or the length of the plate cylinder 2. This also applies in particular if the lower rail 43 or the entire rail body 41 is divided into several segments, possibly of different lengths, in order to achieve further adjustability. Toggle lever drives 39, 40, 42 and compression springs 47 can be assigned to each of the segments independently. In this way, manufacturing tolerances between the various components can be better balanced. In this way, the most uniform possible clamping force is achieved over the entire clamping area.

The arrangement and dimensioning of the compression springs 47 is designed so that the clamping force applied to the lower rail 43 always corresponds to at least a minimum clamping force, which ensures that the pressure plate 45 is securely clamped in the clamping gap between the upper 44 and lower rail 43.

In Figure 3 is a further development of the execution according to Figure 2 shown, the orientation of the plate clamping rail 3 being rotated 180 degrees in the illustration. The toggle lever drive with lower link 39 and upper link 40 is connected to a toggle joint 42 (not visible here) (see FIG Fig. 4 ) and is supported between the rail body 41 and the vertically movable lower rail 43. The upper link 40 is supported upwards with an upper end 40a in a bearing point 43a on the underside of the lower rail 43. The lower link 39 is supported downward with a lower end 39a in a bearing point 41a in the interior of the rail body 41.

Furthermore, a sleeve-shaped first pressure piece 52 is arranged in a guide opening 41b in the rail body 41 so that it can move longitudinally and is seated on a compression spring 47 via an annular collar 52a and has a cylindrical sleeve opening 52c inside.

The first pressure piece 52 is designed on its cylindrical outside with sufficiently large play relative to the guide opening 41b, so that tilting or increased friction cannot occur during longitudinal movements of the pressure piece 52 within the guide opening 41a.

The pressure piece 52 is under a coaxial force which is applied by the compression spring 47 on the annular collar 52a. On the side of the annular collar 52a opposite the compression spring 47, an active surface is formed on the pressure piece 52, from which the force of the compression spring 47 is centrally applied to the toggle joint 42.

The compression spring 47 is supported on its lower side in an annular groove 47a on the rail body 41, which is used to guide the compression spring 47 and is configured concentrically to the guide opening 41b.

Here, too, the bottom area 48, which may be designed to be adjustable for the purpose of adjusting the springs, is shown on the rail body 41.

The first pressure piece 52 is also provided with a hollow cylindrical extension 52b as an extension of the guide opening 41b. The extension 52b protrudes through the area of the toggle joint 42 in the area of an opening 55. The opening 55 is formed by corresponding, approximately semicircular recesses in the mutually facing sides of the links 39, 40.

The pressure pieces 52 protrude with the cylindrical extension 52b through the links 39, 40, which serve as lever segments of the toggle lever drive, so that at the same time the links 39, 40 are guided and secured parallel to the plate cylinder axis in the respective working position.

The first pressure piece 52 is assigned a further, mushroom-shaped pressure piece 53, which has a bolt-shaped extension 53b in the interior of the guide opening 52c is arranged displaceably in the first pressure piece 52 and has an active surface 53a at the opposite end, which has a larger diameter than the opening 55 between the links 39 and 40.

A pressure hose 50 is again arranged opposite the second pressure piece 53 and the toggle lever drive 39, 4, 42 in a pressure space 49 closed by a cover 51 within the rail body 41.

Here too, the rail body 41 forms, with the cover 51 in the upper area, a parallel guide for the vertical movement of the lower rail 43.

The pressure hose 50 is again coupled to at least one pneumatic line via a valve control, via which the pressure hose 50 is supplied with compressed air and inflated, so that, while being supported on the cover 51, it exerts a force against the toggle lever drive 39, 40, via the second pressure piece 53, 42 exerting tension spring 47. The force applied by the pressure hose 51 acts via the second pressure piece 53 on the first pressure piece 52 and thus against the force of the spring 47.

To limit the travel of the toggle lever drive in the direction of the pressure chamber 49, the cover 51 is provided with a stop surface 51a, which extends over the bottom of the cover 51 in the area of the toggle joint 42.

Alternatively, such stops can also be integrated on the pressure pieces 53, for example in the area of the active surface 53a, so that they are supported against the rear wall of the cover 51 (see FIG Figure 5 ).

For the introduction of force when the pressure hose 50 is pneumatically inflated onto the active surface 53a of the second pressure piece 53, a force-conducting element 56 in the form of a metal sheet is provided. The force control element 56 can be attached to the pressure hose 50 and extends over several of the pairs of the first 52 and second pressure pieces 53 arranged on a common toggle lever drive. The assignment of such force control elements 56 to the respective toggle lever drives 39, 40, 42 is shown in FIG Figure 4 shown. Here there is one force control element 56 per toggle lever drive over all openings 55 and thus also over the pressure pieces 52, 53 arranged there in the assembled state.

Figure 4 shows basically two toggle lever drives 39, 40, 42, the arrangement of the openings 55 in the transition between the links 39, 40 on both sides to the toggle lever joint 42 being shown. The links 39, 40 are arranged as a paired package between the rail body 41 and the lower rail 43: Each toggle lever drive has three openings 55, each of which is assigned a pair of pressure pieces 52, 53.

In Figure 3 and Figure 4 a tension spring 54 is also shown, which engages the lower rail 43 and is fastened to the rail body 41. One or two such tension springs 54 are each assigned to a toggle lever drive, but can also be assigned to several toggle lever drives as required and are used to maintain contact between the loosely interacting individual elements of the toggle lever drive lower rail 43, upper link 40 and lower link 39 at the joints or hinge points 41a , 42 and 43a.

Instead of the illustrated tension springs 54, for the above-mentioned purpose, of course, in a correspondingly structurally adapted arrangement, e.g. Compression springs or other non-positive holding devices are used.

In Figure 5 and Figure 6 functional details of a toggle lever drive are shown, which again emphasize the simplicity of the structure of the plate clamping rail.

At Figure 5 the function of the assembly of the toggle lever drive is to be explained. Across from Figure 3 Here, each force guide element 56 is connected to a pressure piece 53 by means of a holding element 57 of a latching connection which is arranged on the active surface 53a of the second pressure piece 53. Thus, all of the second pressure pieces 53 belonging to a toggle lever drive can also be hung on a force guide element 56 by means of the holding elements 57 and can be easily assigned to the first pressure pieces 52 in the openings 55 of a toggle lever drive. For this purpose, the (according to the exemplary embodiment) three pressure pieces 52 of a toggle lever drive 39, 40, 42 are connected to the corresponding openings 55 (see FIG Figure 4 ) assigned to compression springs 47 on the rail body 41 corresponding to the respective annular grooves 47a.

Furthermore, each holding element 57 can serve as a stop to limit the opening movement of the toggle lever drive in the direction of the cover 51. Each pressure piece 53 then abuts against the vented pressure hose 50 resting on the cover 51 via a respective holding element 57 and the toggle lever drive is in a play-free, secured and open state with the cooperation of the tension spring 54. In this case, no separate stop surface 51a is provided on the cover 51, since this is now formed by the cover 51 itself.

To assemble the clamping mechanism of the plate clamping rail:
In order to be able to insert the respective upper 40 and lower link 39 together with the respective lower rail 43 in the rail body 41, the compression springs 47 must be pretensioned, since otherwise the toggle lever drive would be in the extended position and could not be inserted. Therefore, each first pressure piece 52 is braced against the respective compression spring 47 resting on the rail body 41 by means of a retaining screw 58 which is screwed into a thread inside the guide opening 52c. The retaining screw 58 can be tightened up to the stop on the rail body 41 against a shoulder on the cylindrical collar 52a of the first pressure piece 52, so that the pressure piece 52 reaches its lowest possible position in the rail body 41.

This initial assembly position of a toggle lever drive, given under prestressing of the retaining screw 58, is shown in FIG Figure 5 shown in solid lines. Thus, the upper 40 and lower links 39 can easily be inserted into the bearing points 41a, 43a on the rail body 41 and on the lower rail 43, which is also inserted, by joining their toggle joint 42. To conclude this assembly process, the lower rail 43 is also secured by means of the tension spring 54, the tension spring 54 in FIG Figure 5 clarity because of not shown. The spring force of the tension spring 54 pulls the lower rail 43 against the upper link 40 by means of its bearing point 43a, so that the upper link 40 is positioned against the lower link 39 via the toggle joint 42 and the lower link 39 in the bearing point 41a on the Rail body 41 is made free of play.

The second pressure pieces 53 are then inserted into the guide openings 52c of the first pressure pieces 52. In a preferred embodiment, this process can take place together with the force guide elements 56 latched onto the holding elements 57, onto which the pressure hose 50 belonging to the unit is then inserted.

Alternatively, the pressure pieces 53 are used individually if the force guide elements 56 are loosely inserted or together with a respective pressure hose 50, e.g. connected by gluing, installed.

Finally, at the end of the assembly process, the cover 51 is fastened to the rail body 41 to close the plate clamping rail 3. The lower rail 43 is guided with little play between the corresponding guide surfaces on the rail body 41 and on the cover 51. In each case, an air supply connected to each of the pressure hoses 50 inserted within the plate clamping rail 3 is required to operate the plate clamping rail by means of compressed air. These air supply lines are led out of the plate clamping rail 3 through openings in the cover 51, which are not shown in the figures.

Only then can the retaining screws 58 with washers 59 be removed from the assembly of the plate clamping rail. The installation position that occurs after the retaining screws 58 have been removed is shown in dashed lines, with the toggle lever drive then under load from the compression spring 47 via the pressure piece (s) 52 in an almost stretched clamping position between the rail body 41 and the lower rail resting on the upper rail 44 43 is located.

During the sequential removal of the retaining screws 58, one pressure piece 52 after the other is set by its compression spring 47 against the toggle lever drive. The toggle lever drive is then supported on the cover 51 via the second pressure piece 53. The force build-up from the various compression springs 47 takes place successively and without excess force, since the toggle lever drives can move independently of the pressure pieces 52, 53.

The end position of the toggle lever drive is shown in broken lines, the pressure piece 53 with the holding element 56 of the latching device being supported on the pressure hose 50 which rests on the inner wall of the cover 51.

In Figure 6 Finally, functional details of a toggle lever drive with regard to the embodiments of the bearings of the links 39, 40 and of the toggle joint 42 are shown. Here the cylindrical extension 52a of the first pressure piece 52 has been omitted for the sake of clarity.

The lower link 39, the upper link 40 and the lower rail 43 are coupled relative to one another and to the rail body 41 by loose bearing points 41a, 42, 43a (sliding bearings). The joint function of these bearing points 41a, 42, 43a is ensured by the holding force of the tension spring 56. For this purpose, the tension spring 56 is fastened under a predefined tensile stress between the lower rail 43 and the rail body 41, the force flow resulting from the tensile stress including the toggle lever drive. In this way, the components of the lower link 39, the upper link 40 and the lower rail 43 are coupled to one another and on the rail body 41 in the bearings 41a, 42, 43a without play.

Frequent switching movements when opening and closing the plate clamping rail for clamping printing plates result in setting effects in the bearing points 41a, 42, 43a and minimal wear on the bearing surfaces during operation of the printing machine. This effect has the effect that the links 39, 40 align themselves between the bearing points 41a and 43a in their end position when a pressure plate is clamped in a rather elongated position relative to one another. This leads to an increased clamping force, which keeps the system operationally safe.

In summary, the main effects of the new plate clamping rail can be characterized as follows:
The pressure hose 50 no longer presses directly on the toggle lever drive to open the clamping of the plate clamping rail. The force of the pressure hose 50 is centrally guided directly to the pressure spring 47 via pressure pieces 53. The force effect of the pressure hose 52 on the compression spring 47 is thus given without losses due to deteriorated leverage.

The toggle lever drive used is designed in such a way that, when the pressure plate 45 is clamped, it does not overturn over dead center, so that there can also be no reversal of the direction of force within the movable lower rail 43.

Furthermore, compared to systems that push the dead center of the toggle lever drive into an end position at a stop, no loss of clamping force has to be compensated for. This would be necessary because the effective length of the toggle lever drive is shortened again after passing through the top dead center and the clamping force is thereby reduced.

The pressure piece is guided in an opening 55 through the toggle lever drive. The pressure pieces 52 thus protrude through the lever segments (links 39, 40), which are thus simultaneously guided axially in their position.

Since two pressure pieces 52, 53 which can be displaced one inside the other are provided per compression spring 47, the first pressure piece 52 can apply the spring force centrally to the toggle lever drive when closing. The second pressure piece 53 directs the force of the pressure hose 50 via the first pressure piece 52 against the compression spring 47.

The second pressure piece 53 is designed to be axially displaceable in the first pressure piece 52 so that individual compression springs 47 can be pre-tensioned via a thread inside the first pressure piece 52 by means of a retaining screw 58, supported on the rail body, in order to carry out assembly, disassembly or repairs. The pressure hose 50 then does not have to be inflated.

The second axially displaceable pressure piece 52 then remains in its position and thus does not cause any opening of the plate clamping rail 3.

If at least two pressure pieces 52 are guided by a toggle lever drive, this axial displaceability is necessary, since otherwise the respective second compression spring 47 would work against the first spring via the toggle lever package and lead to tension forces and damage within the plate clamping rail. A tension spring device is used to maintain contact between the loosely interacting elements, lower rail 43, upper link 40 and lower link 39. Other devices such as compression springs are also conceivable.

Changes in attitudes are not necessary. However, variants of settings for different panel thicknesses are possible.

Toggle lever drives, compression springs and bottom rails can be divided into different and possibly differently wide segments across the format width. In this way, manufacturing tolerances of the components can be better compensated for. A clamping force that is as uniform as possible over the entire clamping area is achieved.

List of reference symbols

1

Plate cylinder

2

Cylinder channel

3

Printing plate clamping device, plate clamping rail

4th

Rail body

5

ground

6th

left side border

7th

right border

8th

Bearing point

9

lower rail coupling, lower link

10

upper rail coupling, upper link

11

lower ends

12

upper ends

13

lower ends

14th

upper ends

15th

Bearing point

16

Head rail

17th

camp

18th

Recess

19th

Terminal block

20th

Plate support

21st

printing plate

22nd

Guide rail

23

Printing room

24

tube

25th

Recess

26th

Compression spring

27

Recess

28

Bellows (pneumatic)

29

Compression spring

30th

Recess

39

lower handlebar

39a

lower handlebar end / bearing point of the toggle lever drive in the rail body

40

upper handlebar

40a

upper handlebar end / bearing point of the toggle lever drive on the lower rail

41

Rail body

41a

Depository

41b

Guide opening

42

Toggle joint

43

Lower rail

43a

Depository

44

Head rail

45

Printing plate, printing form

46

Pressure piece

47

Compression spring

47a

Ring groove

47b

Guide opening

48

Bottom part of the ring groove

49

Printing room

50

pressure hose

51

cover

51a

Stop surface

52

first pressure piece

52a

annular collar

52b

sleeve-shaped extension

52c

Hole / guide opening / thread

53

second pressure piece

53a

Effective area

53b

bolt-shaped extension

54

Tension spring

55

opening

56

Force control element

57

Stop / holding element

58

Retaining screw

59

Washer

Claims (10)

1. A device for clamping flexible pressure plates (45) at a plate cylinder (1) of a sheet-fed offset printing press comprising plate tensioning rails (3) arranged axially parallel in a cylinder channel (2), comprising a toggle lever drive for generating a clamping movement comprising an upper and lower lever element (39, 40) each, wherein the lever elements (39, 40) are coupled by means of a toggle lever joint (42), and comprising a spring assembly, which is arranged in the area of the toggle lever joint (42) so as to act on the toggle lever drive, so that, by the action of the spring assembly in the plate tensioning rail (3), the clamping movement for pressure plates (45) into a clamping position can be performed by means of displacement of the lever elements (39, 40),
   and, to open the plate tensioning rail (3), comprising one or several expandable pneumatic or hydraulic elements (50), respectively, which are assigned to the toggle lever drive for displacing the lever elements (39, 40) from a clamping position into an open position,
   that a lower rail (43) is provided, which performs the clamping movement in combination with the lever elements (39, 40),
   that the lower rail (43) is arranged so as to be displaceable linearly and essentially radially to the plate cylinder (1) with respect to an upper rail (44), which is firmly connected to a rail body (41) of the plate tensioning rail (3),
   and that, to move the lower rail (43) into an open position with respect to the upper rail (44), one or several expandable pneumatic or hydraulic elements (50), respectively, are provided, which are arranged so as to act on the spring assembly, which strains the toggle lever drive, to displace the lever elements (39, 40) from the clamping position into an open position,
   wherein the spring assembly is formed by individually arranged pressure springs (47),
   characterized in
   that the pressure springs (47) are arranged so as to be supported on the rail body (41) of the plate tensioning rail (3) and so as to act on a first transfer element (52) each,
   wherein each first transfer element (52) is arranged at the rail body (41) so as to be guided in a longitudinally movable manner between a pressure spring (47) and so as to act centrally on the toggle lever joint (42).
2. The mechanism according to claim 1,
   characterized in
   that the pneumatic or hydraulic elements (50), respectively, are arranged so as to be supported between a cover (51), which is connected to the rail body (41) to close the plate tensioning rail (3), and a second transfer element (53) each, which is coupled to each first transfer element (52) so as to be capable of being shifted all the way against a stop.
3. The mechanism according to one or several of claims 1 to 2,
   characterized in that the expandable elements are embodied as pneumatically inflatable, elastic pressure tubes (50).
4. The mechanism according to one or several of claims 1 to 3,
   characterized in that the lever elements are formed as lower connecting rod (39) and upper connecting rod (40) and are embodied so as to be connected to one another in an articulated manner under a non-positive or positive guidance in an open bearing point, which forms the toggle lever joint (42).
5. The mechanism according to claim 1 to 4, characterized in
   that the compression springs (47) are arranged so as to be supported on a rail body (41) of the plate tensioning rail (3) and so as to be capable of being displaced on at least one adjustable control element each, such that the clamping force of the plate tensioning rail (3) can be adjusted by means of the adjusting elements.
6. The mechanism according to one or several of claims 1 to 5,
   characterized in
   that the pressure tubes (50) are arranged such that the force components created in response to the inflation thereof are introduced directly to the second transfer elements formed as second pressure pieces (53) and without contacting the connecting rods (39, 40), so that this effect is guided solely against the pressure springs (47) by means of the pressure pieces (53).
7. The mechanism according to one or several of claims 1 to 6,
   characterized in
   that, with an end located opposite the pressure spring (47), each of the first pressure pieces (52) sticks out from an opening (55) in the toggle lever drive (39, 40, 42), so that the pressure pieces (52) secure the position of the connecting rods (39, 40) axially in the direction of the plate cylinder (1) in their position.
8. The mechanism according to one or several of claims 1 to 7,
   characterized in
   that the second pressure piece (53) is arranged in the first pressure piece (52) in an axially shiftable manner, that each first pressure piece (52) is arranged in a pre-tensionable manner with respect to the rail body (41) by means of a retaining screw (58) to optionally pre-tension the pressure spring (47) cooperating with said first pressure piece, and that at least two pressure pieces (52) are guided by a toggle lever drive (39, 40, 42).
9. The mechanism according to one or several of claims 1 to 8,
   characterized in
   that a tension spring or pressure spring or mechanical position fixation with respect to the assignment to the rail body (41) is provided for maintaining contact between the loosely cooperating elements lower rail (43), upper connecting rod (40), and lower connecting rod (39).
10. The mechanism according to one or several of claims 1 to 9,
    characterized in
    that the toggle lever drives (39, 40, 42), pressure springs (47), and the lower rail (43) are arranged so as to be divided into different segments over the format width.

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