WO2018220645A9

WO2018220645A9 - Tool post design for dragknife sheet cutting

Info

Publication number: WO2018220645A9
Application number: PCT/IN2018/050341
Authority: WO
Inventors: Viswesh SRINIVASAN
Original assignee: Srinivasan Viswesh
Priority date: 2017-05-29
Filing date: 2018-05-29
Publication date: 2019-06-27
Also published as: WO2018220645A1

Abstract

Packing boxes are usually made from flat sheet of raw material. Operations like drilling, creasing, perforation, cutting etc. to be done on the sheet, before it can be folded into a box. An innovative tool holding post is proposed in this invention, which enables all the above operations to be performed, with minimal number of degrees of freedom or CNC axis. Such a tooling system results in a low cost and compact cutting system for sheet cutting.

Description

TOOL POST DESIGN FOR DRAGKNIFE SHEET CUTTING

FIELD OF INVENTION

[001] This invention relates to the field of CNC profile cutting. This invention proposes a special tool and cutting method, which enables to perform multiple operations like cutting, creasing, perforating, drilling etc. with minimal number of CNC axis. The present application is based on, and claims priority from an Indian Application Number, 201741018707 filed on 29^th May, 2017, the disclosure of which is hereby incorporated by reference herein.

BACKGROUND OF INVENTION

[002] In CNC profile cutting machines for sheets, it is often required to perform multiple operations like drilling, creasing, perforating, cutting etc. on the sheet.

[003] Above operations cannot be performed with a single tool. Each operation requires a separate tool.

[004] Each tool also needs 2 CNC axis ( Z and theta axis), in addition to basic XY axis.

[005] This results in an expensive system.

[006] In existing system, multiple tools are mounted next to each other. The XY offset between tools need to be calibrated accurately. This is prone to operator errors.

[007] Also mounting tools next to each other decreases the effective cutting stroke of the machine.

[008] Hence there is a need to develop an intelligent tool holding system and cutting method to overcome the above problems. OBJECT OF INVENTION

[009] The main object of this invention is to develop an efficient tool holding system that can hold the multiple tools needed for sheet cutting and folding operations.

[0010] To develop a tool indexing system such that the tools are always at the same XY position with respect to CNC axis, when the particular tool is indexed to cutting position.

[0011] To develop a tool holding system that maximizes the size of sheet that can be cut on the given XYZ cartesian CNC me.

[0012] These and other objects of the embodiments herein will be better appreciated and understood when considered in conjunction with the following description and the accompanying drawings. It should be understood, however, that the following descriptions, while indicating preferred embodiments and numerous specific details thereof, are given by way of illustration and not of limitation. Many changes and modifications may be made within the scope of the embodiments herein without departing from the spirit thereof, and the embodiments herein include all such modifications.

BRIEF DESCRIPTION OF FIGURES

[0013] This invention is illustrated in the accompanying drawings, throughout which like reference letters indicate corresponding parts in the various figures. The embodiments herein will be better understood from the following description with reference to the drawings, in which: [0014] FIG. 1 depicts the proposed multiple tool holding station with indexing capability.

[0015] FIG. 2 depicts conventional multi tool mount procedure, where tools are mounted side by side on its own Z and theta axis.

[0016] FIG. 3 depicts the details of the tool holding plate design.

DETAILED DESCRIPTION OF INVENTION

[0017] The embodiments herein and the various features and advantageous details thereof are explained more fully with reference to the non-limiting embodiments that are illustrated in the accompanying drawings and detailed in the following description. Descriptions of well-known components and processing techniques are omitted so as to not unnecessarily obscure the embodiments herein. The examples used herein are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. For example, it should be noted that while some embodiments are explained with respect to cutting of cardboard material for packing box manufacturing, any other application may also incorporate the subject matter of the invention with little or no modifications. Accordingly, the examples should not be construed as limiting the scope of the embodiments herein.

[0018] The embodiments herein describe an automated cutting method for performing multiple operations like drilling, creasing, perforating, cutting on sheets. Referring now to the drawings, and more particularly to FIGS. 1 through 3, where similar reference characters denote corresponding features consistently throughout the figures, there are shown embodiments.

[0019] FIG 1 shows a sheet of raw material 107 resting on base 108.

[0020] Figl shows three cutting tools: Drag Knife (103), Creasing/perforating wheel tool (104), mini drill motor (105) etc.

[0021] The tools are mounted on a tool holding plate 111. [0022] The tool post has an indexing degree of freedom (102). Using this, any desired tool can be brought to the bottom most sheet cutting position.

[0023] The tool holding plate 111 is also shown in FIG 1.

[0024] The plate 111 is designed such that the cutting edge of all the tools are at the same XY point (114) with respect to the theta axis 101. (when indexed to the bottom most cutting position).

[0025] The cutting edge is typically lying on the axis 101 or at a known XY offset from the 101 axis.

[0026] The tool plate 111 is in turn mounted on the frame 106, which is attached to the theta axis 101.

[0027] 112 is the motor/actuator, doing position control of 101 axis.

[0028] The whole 101 axis is in turn mounted on the Z axis plate 109, which moves up/down along Z axis 110. This plate 109 is in turn mounted on a CNC machine with XYZ degrees of freedom.

[0029] All axis 101, 102, 110, X, Y are controlled by a CNC controller.

[0030] CNC controller will first move tool to the desired XY start/pierce point.

[0031] Then the desired cutting tools is brought to the bottom most cutting position by indexing along axis 102. The Zaxis 110 is moved down to pierce the sheet 107 to required depth.

[0032] Then the tool is moved in tangential control mode in X, Y and theta axis, to cut, perforate, crease the sheet as per design in the computer.

[0033] The Yaxis in the coord system 113 is going into the plane of the paper. [0034] Such a tool holding system results in all the cutting tools available at a single position and also enables a single Z and theta axis to control all the tools.

[0035] FIG 2 shows the cutting Knife 103, Creasing tool 104 and drill motor 105 located next to each other. Each tool is mounted on its own Z and A axis (201, 202, 203, 204, 205, 206). Such a system needs a minimum of 8 degrees of freedom or CNC axis resulting in an expensive system.

[0036] FIG3 shows the tool holding plate in more detail.

[0037] Different tools have different thickness. Hence different steps (303) are machined on the plate, such that all tool centers are on the same plane/level. Distance 301 is maintained equal to Distance 302 by design etc.

[0038] Drag knife, creasing tool and drill tool has been used as example. Any other tool required for sheet cutting operation like laser, oscillating knife, pen plotter, camera etc. can also be mounted on the indexing tool post and this invention covers all such tools mounted on the proposed tool post design.

[0039] The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

Claims

STATEMENT OF CLAIMS I claim:

1. An automated CNC cutting system (100) comprising:

Multiple tools like Drag/Oscillating knife (103), Creasing/perforating wheel (104), Drilling tool (105) etc., mounted on an indexing tool post (111), which rotates about axis 102.

2. The automatic cutting system (100) of claiml, where the tool post (111) is designed such that, the cutting tip of all the tools comes to the same XY point (114) ( relative to tool post 111 ), where it will engage with the sheet (107) being cut.

3. The automatic cutting system (100) of claiml, where the toolpost (111) is in turn mounted on a rotary axis (101), such that the bottom point (114) of the tool is lying on the axis 101 or at a known distance from the axis 101.

4. The automatic cutting system (100) of claiml, where the toolpost (111) and rotary axis (101) are in turn mounted on a conventional XYZ CNC system, controlled by a CNC controller.

5. The automatic cutting system (100) of claiml, with tool post (111) mounted on a rotary axis (101), capable of holding multiple tools and capable of indexing the desired tool to the bottom cutting position, such that the cutting edge is at a known location from a rotary axis (101).