Tool holding assembly and assembly

Abstract

A tool clamping assembly (38) for clamping a blanking tool (40) intended for use in a blanking station of a sheet processing machine has a frame (46) and at least one clamping element (48), the blanking tool (40) being clamped to the frame (46). The frame (46) has an alignment mechanism adapted to align the blanking tool (40) in a first direction. Furthermore, the frame (40) has at least one support surface (60) oriented to support the blanking tool (40) in a second direction perpendicular to the first direction and at least one abutment surface (62) oriented to support the blanking tool (40) in a third direction perpendicular to the first and second directions. The clamping element (48) is displaceable between an open position and a clamping position, the clamping element (48) being adapted to clamp the blanking tool (40) against the support surface (60) and the abutment surface (62). Furthermore, a blanking tool assembly having such a tool clamping assembly is shown.

Description

TECHNICAL FIELD

[0001] The present invention relates to a tool clamping assembly for clamping a blanking tool and an assembly comprising said tool clamping assembly. BACKGROUND

[0002] Sheet processing machines, also known as converting machines, are used in the packaging industry for processing raw material, e.g. cardboard, paper or foil, into intermediate products or finished products, usually in the form of sheets. The converting operations can for example include printing, cutting, scoring, blanking, punching and / or folding and gluing. Typically, separate operations are performed in subsequent processing stations of the sheet processing machine, where the sheets are transported from one processing station to the subsequent processing station by a transport mechanism. The sheets can be collected into a vertical stack after conversion in a designated stacking area of the sheet processing machine.

[0003] The blanking operation involves breaking the score in the sheet formed in a previous processing step. This results in a blank being punched out of the sheet. To this end, the blanking station can for example comprise an upper male blanking tool and a lower female blanking tool assembled vertically to each other. The upper blanking tool is made of a pusher slightly smaller than the periphery of the blank. The lower blanking tool is made of longitudinal and transversal bars forming a grid corresponding to the periphery of the blank. When the upper blanking tool is lowered, the blank can fall through the space of the grid and pile up vertically.

[0004] The quality of this blanking operation depends on the correct alignment of the blanking tool used in the corresponding blanking station. Therefore, a mechanism for aligning and securing the position of the blanking tool used is necessary. Typically, the blanking tool has to be changed between different production batches to correspond to the shape and / or size of the blank required. In order to reduce the downtime of the sheet processing machine, a mechanism is needed which allows a quick change of the blanking tool while providing a reliable alignment of said blanking tool. SUMMARY

[0005] It is an object of the present invention to provide a simple device for aligning and securing a blanking tool.

[0006] It is an object of the present invention to provide a simple device for aligning and securing a blanking tool.

[0007] The present invention is based on the idea of providing a device for securing a blanking tool against movement in any direction by a combination of two simple mechanisms, i.e. by a combination of an alignment mechanism and a clamping element.

[0008] In order to further ensure the secured position of the blanking tool, the clamping element exerts a clamping force on the blanking tool, in particular in the clamping position, wherein the clamping surface has a component in the second direction and a component in the third direction. Thus, the clamping can be adapted to secure the position of the blanking tool in both perpendicular directions at the same time.

[0009] In order to allow an easy transition between the open position and the clamping position, the clamping element can be displaced between the open position and the clamping position by a movement in the second direction, in particular by a movement initiated by a piston arranged in the frame and connected to the clamping element.

[0010] In a variant, the clamping element is connected to the frame by a carrier element, wherein the carrier element is connected to the frame by a first end portion thereof and to the clamping element by a second end portion of the carrier element.

[0011] Preferably, the carrier element is connected to the piston at the first end portion. Thus, the clamping element can be displaced between the open position and the clamping position by means of the carrier element by a movement of the piston, and vice versa.

[0012] A plurality of clamping elements can be connected to the same carrier element. Furthermore, the tool clamping assembly can comprise a carrier element for each clamping element.

[0013] The clamping element can be rotatably connected to the carrier element to allow a change of alignment of the clamping element between the open position and the clamping position.

[0014] In an embodiment, the clamping element and the carrier element can be connected by a pin of the carrier element and a sleeve or bushing of the clamping element.

[0015] The clamping element can be rotatably connected to the carrier element by a first end portion and adapted to rotate when displaced between the open position and the clamping position, wherein a second end portion is directed towards the carrier element, wherein the second end portion is adapted to clamp the blanking tool against a support surface and an abutment surface of the frame. In this way, a particularly simple and fast mechanism is provided which allows a quick exchange and securing of the blanking tool.

[0016] The clamping element and the carrier element form an angle relative to each other in the open position of the clamping element of less than 90°, in particular. This provides an arrangement of the clamping element and the carrier element relative to each other, wherein the carrier element effectively forms a protrusion which can be used to interact with the blanking tool.

[0017] Furthermore, if the clamping element and the carrier element are rotatably connected to each other, a preferred direction of rotation can be provided. Preferably, in this variant, the smallest angle between the clamping element and the carrier element in the open position is 10°.

[0018] In another variant, the tool clamping assembly further comprises a leaf spring connected to the clamping element, in particular a leaf spring further connecting the clamping element and the carrier element. The leaf spring can hold the clamping element in a tilted state in the open position to ensure a correct relative alignment of the clamping element with respect to the carrier element while still allowing a relative movement of the carrier element when moving between the open position and the clamped position. At the same time, the leaf spring can be used to realign the clamping element when the clamping element is displaced from the clamped position to the open position.

[0019] Furthermore, the carrier element can comprise a cover arranged at the second end portion. The cover can prevent a movement, in particular a rotation, of the carrier element in the direction of the cover to prevent misalignment of the carrier element.

[0020] The alignment mechanism is preferably connected to the frame. In one embodiment, the alignment mechanism is a clamp mounted on the frame.

[0021] The object of the present application is further solved by a blanking tool assembly comprising a tool clamping assembly as described before and a blanking tool.

[0022] The clamping element in particular presses against a contact surface of the blanking tool in the clamped position, wherein the contact surface in particular is located in a corner of a receiving space of the blanking tool. Thus, the blanking tool is pressed against the support surface and the abutment surface of the frame by the clamping element pressing against the contact surface of the blanking tool. In other words, the blanking tool is fixed in the second and third direction by clamping the blanking tool between the support surface, the abutment surface and the clamping element.

[0023] The contact surface can be part of a step structure of the blanking tool. The step structure can be adapted to cooperate with further components of the tool clamping assembly, for example with the cover of the carrier element.

[0024] In order to provide a flat surface of the blanking tool, the blanking tool can have a recess in which the clamping element can be contained, in particular the clamping element and the carrier element can be contained when the clamping element is in the clamped position.

[0025] Furthermore, the alignment mechanism can cooperate with the alignment protrusion of the blanking tool. In other words, the blanking tool may include the alignment protrusion for aligning the blanking tool via the alignment mechanism of the frame. In one embodiment, the alignment mechanism may be a trapezoidal clamp that interacts with the alignment protrusion to prevent movement of the blanking tool in a first direction. Attached Figure Description

[0026] Further advantages and features will become apparent from the following description of the invention and the accompanying drawings illustrating non-limiting exemplary embodiments of the invention, wherein:

[0027] - Figure 1 A sheet processing machine including a blanking tool assembly according to the invention is illustrated schematically;

[0028] - Figure 2 A first embodiment of a tool clamping assembly according to the invention is shown. Figure 1 A perspective view of the blanking tool component;

[0029] - Figure 3 Schematally shown in perspective view Figure 2 Blanking tool components;

[0030] - Figure 4 Schematic illustration along Figure 3 A cross-sectional view of the blanking tool assembly of plane AA;

[0031] - Figure 5 A perspective view of a second embodiment of the tool clamping assembly according to the invention is shown, wherein the clamping element is in the open position; and

[0032] - Figure 6 It shows Figure 6 A tool clamping assembly, wherein the clamping element is in the clamping position. Detailed Implementation

[0033] Figure 1 A sheet processing machine 10 is schematically shown, which enables the cutting of blanks from a continuous sheet 12. These blanks are typically intended to be subsequently folded and glued to form packaging boxes. However, the sheet 12 can generally be made of, for example, paper, cardboard, foil, or any other material commonly used in the packaging industry.

[0034] The sheet processing machine 10 comprises a series of processing stations juxtaposed but interdependent in order to form an overall assembly. The processing machine 10 comprises an infeed station 14, followed by a cutting station 16 (also commonly referred to as a punching station) comprising for example a die-cutting machine or a flat-bed printing press 18, in which the sheet 12 is transformed by cutting, a waste stripping station 20 in which most of the waste portion is stripped, a blanking station 22 (also commonly referred to as a receiving station) for separating the blanks (or blanking operation) and an ejection station 24 for removing the residual waste sheet of the punched sheet 12.

[0035] The number and nature of the processing stations can vary depending on the nature and complexity of the transformation operations to be performed on the sheet 12.

[0036] The sheet processing machine 10 also has a conveying device 26 to enable each sheet 12 to be moved individually from the outlet of the infeed station 14 to the ejection station 24.

[0037] The conveying device 26 uses a series of gripper bars 28 mounted so as to be movable by means of two loops of chain 30 placed laterally on each side of the sheet processing machine 10. Each loop of chain 30 travels around a ring which allows the gripper bars 28 to follow a trajectory which successively passes through the cutting station 16, the waste stripping station 20, the blanking station 22 and the ejection station 24.

[0038] Each gripper bar 28 travels on an outward path in a substantially horizontal plane of passage between a driven wheel 32 and an idler wheel 34, then on a return path on the top portion of the sheet processing machine 10. Once returned to the driven wheel 32, each gripper bar 28 is then able to grip a new sheet 12 at the leading edge of the sheet 12.

[0039] In Figure 1 , each processing station is shown in the form of two rectangles which symbolically represent respectively the top portion and the bottom portion thereof positioned on each side of the plane of movement of the sheet 12.

[0040] In Figure 1 , the transverse (or lateral), longitudinal and vertical directions are indicated by an orthogonal spatial system (T, L, V). In the following, these directions will also be denoted respectively as first, second and third directions.

[0041] The terms "upstream" and "downstream" are defined with reference to the direction of movement of the sheet 12 in the second direction L (as indicated by the arrow D in Figure 1 ).

[0042] The blanking station 22 comprises a blanking tool assembly 36 according to the application, which is shown in more detail in Figure 2 .

[0043] The blanking tool assembly 36 comprises a tool clamping assembly 38 and a blanking tool 40.

[0044] Figure 2 The blanking tool 40 shown in Figure 1 is a lower blanking tool, i.e. it is made of longitudinal and transversal bars 42 forming a grid corresponding to the periphery of the blank to be cut from the sheet 12 (see Figure 1 ). The blank can fall through the spaces 44 of the grid and pile up vertically (see ).

[0045] The tool clamping assembly 38 comprises a frame 46 and a plurality of clamping elements 48 (see Figure 3 ), which are connected to the frame 46 by means of carrier elements 50, wherein each clamping element 48 is associated with one of the carrier elements 50.

[0046] In Figure 3 , selected components of the blanking tool assembly 36 are shown.

[0047] The blanking tool 40 comprises an alignment protrusion 52, which cooperates with an alignment mechanism 54 of the clamping tool assembly 38. In the shown embodiment, the alignment mechanism 54 is a cam interacting with a lateral surface 56 of the alignment protrusion 52.

[0048] Furthermore, the blanking tool 40 rests in a receiving portion 58 of the frame 46, wherein the receiving portion 58 comprises a support surface 60 and an abutment surface 62.

[0049] The clamping elements 48 are cams rotatably connected to the respective carrier elements 50.

[0050] This arrangement is shown in more detail in Figure 4 , Figure 4 is a cross-sectional view along the plane A-A indicated in Figure 3 .

[0051] The carrier elements 50 are associated with the frame 46 at the first end portion 64 of the carrier elements 50 by means of a piston 66. The piston 66 is movable in a third direction, i.e. vertically, as indicated by the arrow P3 in Figure 4 .

[0052] The clamping elements 48 are connected with the carrier elements 50 at the second end portion 68 of the carrier elements 50 by means of a pin 70 housed in a bushing of the clamping elements 48.

[0053] The bushing of the clamping elements 48 is arranged at a first end portion 72 of the clamping elements 48. A second end portion 74 at the opposite end of the clamping elements 48 is pressed against a contact surface 76 of a receiving space 78 of the blanking tool 40.

[0054] The clamping element 48 and the carrier element 50 are oriented relative to each other such that they form an angle a, which is preferably smaller than 90°, i.e. the second end portion 74 of the clamping element 48 is pointing towards the receiving space 78 of the blanking tool 40.

[0055] In the following, the mode of action of the tool clamping assembly 38 will be described.

[0056] When the blanking tool 40 is to be fixed in the blanking station 22 (see Figure 1 ), in a first step, the blanking tool 40 is aligned above the frame 46 such that the protrusion 52 is aligned between the trapezoidal portions of the alignment mechanism 54 by lowering the blanking tool 40, i.e. by moving the blanking tool 40 along the third direction. Thus, the blanking tool 40 is fixed against a movement along the first direction as indicated by arrow P1 in Figure 3 .

[0057] At this point, the clamping element 48 is in an open position, i.e. the clamping element 48 does not exert a force on the blanking tool 40.

[0058] In a second step, the piston 66 is moved along the third direction, i.e. vertically downwards, for example by a (not shown) linear drive. Thus, the clamping element 48 comes into contact with the contact surface 76 of the blanking tool 40. Moreover, the clamping element 48 rotates with its second end portion 74 towards the carrier element 50 until the second end portion 74 is locked in the corner of the receiving space 78 of the blanking tool 40 as shown in Figure 4 .

[0059] In this clamping position of the clamping element 48, a force is exerted by the clamping element 48 onto the blanking tool 40, which force has a component F2 and a component F3 as indicated by the arrows in Figure 4 .

[0060] This results in pressing the blanking tool 40 against the support surface 60 along the second direction and against the abutment surface 62 along the third direction.

[0061] In other words, the blanking tool 40 is clamped between the receiving portion 58 of the frame 46 and the clamping element 48 and is prevented from moving along the second and third directions as indicated by arrows P2 and P3 in Figure 3 .

[0062] If the blanking tool 40 is removed or replaced, the simple two-step procedure is done in reverse order.

[0063] Thus, the blanking tool assembly according to the present application provides a very simple, easy to use and reliable mechanism for use in the blanking station 22 of the sheet processing machine 10.

[0064] Figure 5 andFigure 6 Selected components of a second embodiment of the tool clamping assembly 38 are shown. The second embodiment substantially corresponds to the first embodiment, such that only the differences between the first and second embodiments will be discussed below. Identical and functionally identical components have the same reference numerals.

[0065] In the second embodiment, the tool clamping assembly 38 further includes a leaf spring 80 connected to the clamping element 48 and the carrier element 50, wherein the connection to the carrier element 50 is closer to the first end 64 of the carrier element 50 than to the second end 68 of the carrier element 50.

[0066] also, Figure 5 The illustrated embodiment includes a cover 82.

[0067] exist Figure 5 In the open position of the clamping element 48 shown, the leaf spring 80 is relaxed and defines an angle α between the support element 50 and the clamping element 48. In other words, the second end portion 74 of the clamping element 48 cannot rotate closer to the cover 82 than defined by the leaf spring 80.

[0068] exist Figure 6 The clamping element 48 is shown in the clamping position, held in tension by the leaf spring 80. Therefore, once the clamping element 48 moves back to the open position, the leaf spring 80 relaxes and pushes the clamping element 48 back to the open position. Figure 5 The location shown.

[0069] Therefore, during the operation of the tool clamping assembly 38, the orientation of the clamping element 48 is well defined at any point.

Claims

1. A tool clamping assembly for clamping a blanking tool intended for use in a blanking station (22) of a sheet processing machine (10), the tool clamping assembly (38) having a frame (46) and at least one clamping element (48) to which a clamping tool (40) is clamped to the frame (46), the frame (46) having an alignment mechanism (54) adapted to align the blanking tool (40) in a first direction, the frame (46) further having at least one support surface (60) oriented to support the blanking tool (40) in a second direction perpendicular to the first direction and at least one abutment surface (62) oriented to support the blanking tool (40) in a third direction perpendicular to the first and second directions, the clamping element (48) being displaceable between an open position and a clamping position, the clamping element (48) being adapted to clamp the blanking tool (40) against the support surface (60) and the abutment surface (62), characterized in that the clamping element (48) exerting a clamping force on the blanking tool (40) in the clamping position, wherein the clamping force has a component F2 along the second direction and a component F3 along the third direction.

2. The tool clamping assembly according to claim 1, wherein the clamping element (48) is displaceable between the open position and the clamping position by movement in the second direction.

3. The tool clamping assembly according to claim 2, wherein the clamping element (48) is displaced between the open position and the clamping position by movement initiated by a piston (66) arranged in the frame (46) and connected to the clamping element (48).

4. The tool clamping assembly according to claim 1, wherein the clamping element (48) is connected to the frame (46) by a carrier element (50), wherein the carrier element (50) is associated with the frame (46) by a first end portion (64) thereof and with the clamping element (48) by a second end portion (68) of the carrier element (50).

5. The tool clamping assembly according to claim 4, wherein the clamping element (48) is rotatably connected to the carrier element (50).

6. The tool clamp assembly of claim 5, wherein, the clamping element (48) being rotatably connected to the carrier element (50) by a first end portion (72) thereof and being adapted to rotate when displaced between the open position and the clamping position, wherein a second end portion (74) of the clamping element (48) faces the carrier element (50), wherein the second end portion (74) is adapted to clamp the blanking tool (40) against the support surface (60) and the abutment surface (62) of the frame (46).

7. The tool clamping assembly according to any one of claims 4 to 6, wherein the clamping element (48) and the carrier element (50) form an angle of less than 90° relative to each other in the open position of the clamping element (48).

8. The tool clamping assembly according to any one of claims 4 to 6, wherein the tool clamping assembly (38) further comprises a leaf spring (80) connected to the clamping element (48).

9. The tool clamping assembly according to any one of claims 4 to 6, wherein the tool clamping assembly (38) further comprises a leaf spring (80) connecting the clamping element (48) and the carrier element (50).

10. The tool clamping assembly according to any one of claims 4 to 6, wherein the carrier element (50) comprises a cover (82) arranged at the second end portion (74).

11. The tool clamping assembly according to any one of claims 4 to 6, wherein an alignment mechanism (54) is connected to the frame (46).

12. A blanking tool assembly comprising a tool clamping assembly (38) according to any one of claims 1 to 11 and a blanking tool (40).

13. The blanking tool assembly according to claim 12, wherein the clamping element (48) is pressed against a contact surface (76) located in a corner of a receiving space (78) of the blanking tool (40) in a clamping position.

14. The blanking tool assembly according to claim 13, wherein the contact surface (76) of the blanking tool (40) is part of a step structure of the blanking tool (40).

15. The blanking tool assembly of any one of claims 12 to 14, wherein, The blanking tool (40) has a recess, which the clamping element (48) can be contained in when the clamping element (48) is in a clamping position.

16. The blanking tool assembly according to claim 15, wherein the clamping element (48) and the carrier element (50) can be contained in the recess when the clamping element (48) is in a clamping position.

17. The blanking tool assembly according to any one of claims 12 to 14, wherein an alignment mechanism (54) cooperates with an alignment protrusion (52) of the blanking tool (40).

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