GB2340427A - Method and apparatus for cutting card, board or other sheet material - Google Patents

Abstract

Apparatus for cutting card, board or other sheet material comprises a cutter which is movable, relative to a base assembly, along a cutting line adjacent to a guide edge. An indicating device is mounted adjacent the guide edge to indicate the exact line of cut. The indicating device is formed by inserting a piece of material and then cutting it using the cutter. The cut piece of material is then attached to the apparatus in the same orientation in which it was cut so that subsequent sheets may be cut with an accurate indicator of the cutting line. Also disclosed is a clamp for firmly locating an article to be cut. The clamp has an adjustable friction surface which contacts the upper surface of the article to be cut and which can be brought to bear down firmly on the article once it is in place.

Description

2340427 METHOD AND APPARATUS FOR CUTTING CARD AND BOARD AND LIKE MATERIALS

This invention relates to a method and apparatus for cutting card and board and like materials. Machines of the kind with which the present invention is concerned may employ a hand-operated cutter head employing a fixed blade, the cutter head being mounted on a linear guide for accurate cutting and trimming of card, board and like sheet materials for use in a variety of applications including mounts for photographic prints and like articles including digitally printed graphic and other matter, whether coloured or otherwise.

A technical area in which cutting machines of the kind described as currently available leave something to be desired includes the provision of means for assisting accurate placement of an article to be cut in relation to the line of cut which the machine actually produces, and the provision of effective means for holding the article to be cut while it is being accurately placed relative to the line of cut, and indeed during the cut itself.

Turning first to the means for determining where the line of cut will be in relation to the machine structure, the following applies.

Currently available cutting machines provide, of course, a straight edge corresponding to the line of cut, and such edge is usually provided with suitable calibration marks in an appropriate scale of length measurement to assist generally in the process of accurate management of dimensions etc in the cutting process. Some machines are capable of cutting a curved edge, likewise, and the inventions of this application are applicable to such machines with modifications, where necessary, as will be readily apparent to the technically competent person.

However, the calibrated straight edge itself is not 2 representative of the actual line of cut. It is close to it but it is not on it due to the fact that the cutting head and the blade itself are inevitably offset slightly to one side of it.

Much the same applies even where a cutting machine is provided with some permanent means (possibly labelled "line of cut") which is intended to provide this function but which is inevitably at least one or two millimetres to one side of the actual line of cut due to (at least) the thickness (or at least one half of the thickness) of the cutting blade itself.

Therefore, if an accuracy greater than one or two millimetres is required, some other approach is needed.

According to the invention there is provided a method and apparatus as defined in the accompanying claims.

In an embodiment of this aspect of the invention there is provided an attachable and cuttable line-of-cutindicating (ultimately strip-form) member. In use, the line-of-cut-indicating member is attached to the cutting machine and in a preliminary cutting operation it is cut by the cutting head in the course of an ordinary cutting operation by the cutting head so as to produce an edge which more exactly indicates where the line of cut produced by the cutting head is located, than do previous indicators.

Then, in all subsequent cutting operations, the indicating member is retained, without being moved, in the position in which it was cut and it then serves as a more accurate indicator of the actual line of cut which the machine will produce and accordingly materials to be cut can be positioned (to within an accuracy limited mainly only by the eyesight of the user) in relation to the intended location of the cut line on the product itself.

In a preferred embodiment the cut-indicating member has attachment means comprising an adhesive strip along one edge of its length.

3 It is also envisaged that the benefits of the invention would be achievable by means of the use of an indicator element which is attachable to the cutting machine by simple releasable clamping or gripping means provided for the purpose. Such clamping or gripping means would be additional to that which is provided for the main article to be cut, although such latter clamping or gripping means is by no means essential for the purposes of the invention, which may be applied to simple cutting machines in which the cutting machine is merely placed on an article to be cut.

A second aspect of the invention relates to a method and apparatus for use in cutting apparatus of the kind described and for use for clamping or holding a board or like material at a selected position so that a user can carry out a cutting operation.

The requirements for a mechanism of this kind are several. Firstly, there is a need to be able to position and hold the article to be cut effectively so that not only can it be firmly held during the actual cut but so that also it can be lightly (yet effectively) held during initial placement.

In many respects the accuracy of cut will depend upon the ease and sensitivity with which the holding mechanism can be operated. When placing the article relative to the anticipated line of cut it is necessary to be able to position the article with, effectively, fingertip control of its position, yet with the assurance that, following a perhaps very slight adjustment of position of a millimetre or two, or even a fraction of a millimetre, the article to be cut will stay exactly where it has been positioned.

In other words, there is a need tc be able to set the level of grip or hold at just that level which will permit the above-described fine level of control. This particular level of grip will vary from job to job. This is partly because the material to be cut varies in density and 4 surface friction characteristics. Likewise, there will be variations in the attitude of the cutting apparatus relative to the vertical (varying from horizontal to nearly vertical) which will significantly affect the tendency of the board or other article being cut to slip accidentally from its adjusted position while the user is checking and verifying that the exact intended line of cut will be achieved.

It will be understood from the above that there is a significant interplay between the means adopted for indicating the actual line of cut to be achieved and the means adopted for holding the article to be cut in an intended position to achieve that line of cut.

It goes almost without saying of course that once the article has been properly position, it must be maintained in ls that position throughout the cutting operation and the holding or gripping device must be able to exert a sufficient level of clamping or gripping force or effect for this purpose.

Previously known mechanisms for carrying out functions of this kind include over-centre mechanisms which suffer from the shortcoming that they are not capable of operating with the required degree of sensitivity as explained above.

other mechanisms do not provide sufficient precision in the control of the clamping or gripping mechanism.

The operating characteristics of an over-centre mechanisms are in fact completely unsuitable for the above described operation since the actual over-centre movement produces its own additional clamping effect which may be much more than is required for a certain type of board or other material to be cut. Also, on each side of the "hump" in the graph of force against time which occurs at the overcentre point, there is respectively less than and more than the required level of force for holding purposes.

Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which Fig 1 shows in block diagram format the main elements of a first embodiment of the invention relating to the provision of indicator means for indicating the line of cut of a cutting machine; Fig 2 shows, likewise in block diagram/flow-chart format the main elements of an embodiment of the invention relating to the provision of controllable clamping or gripping means for the article to be cut; and Fig 3 shows an exploded perspective view of a practical realisation of part of the mechanism indicated in Fig 2.

As shown in Fig 1 of the drawings, there is provided a method and apparatus for indicating the line of cut of a cutting machine 10. The cutting machine comprises cutting means 12 to produce a line of cut, and structure 14 extending lengthwise of the line of cut to provide a guiding and/or clamping and/or other function in relation to the cutting machine.

An indicator element 16 comprises a material which is cuttable by the cutting means 12 and attachment means 18 is provided for the indicator element 16 whereby it is attachable to and detachable from the structure 14 so as to extend across the line of cut produced by cutting means 12.

In use, the indicator element 16 is attached to the structure 14 and the cutting means 12 is caused to cut the indicator element so as to produce an indicator edge 20, and this indicator edge is used in subsequent cutting operations to indicate the line of cut to be produced by cutting machine 10 in an article to be cut. 30 Having thus described the main elements of the invention and their general function, we now look at the structure and arrangement in more detail. Cutting means 12 comprises a cutter head 22 carrying a blade 24 to effect cutting of a article to be cut 26, and also of the indicator element 16. These and other details of 6 a nonlimiting example of a cutting machine to which the invention applies are set forth in our prior patents US-A-4 941 380, GB-A-2 215 554 and GBA2 321 211 to which reference is directed and from which the entire technical disclosure is hereby incorporated herein for disclosure purposes.

The structure 14 extending lengthwise of the line of cut comprises a cutter guide 28. This structure may be integrated with a calibrated edge of the cutting machine and the indicator element 16 may be attached to same, or to clamping means 30 for the article 26 to be cut, so as to extend lengthwise thereof at any convenient location. For example, the indicator element may be attached above or below the calibrated edge of the cutter guide structure.

As to the indicator element 16 itself, in this embodiment it comprises a strip of flexible and transparent plastics material having a lengthwise-extending band of peelable adhesive for its attachment to and detachment from the structure 14. In this embodiment, the indicator element is of thickness of about 1 to 3 millimetres and has a degree of stiffness so as to maintain naturally its linear format once the latter is adopted. Considerable variation however in the material and physical characteristics of the indicator element are possible within the limits provided by the cutting machine itself, and the necessity for the indicator element to be cuttable by the cutter blade or other cutting element itself.

Turning now to the embodiment of Figs 2 and 3, apparatus 100 for cutting card and/or board and or other sheet material is of the same general kind as that of the preceding embodiment and comprises holding means 102 for an article to be cut 104 in the form of a sheet of material, and cutting means (as described previously) is provided to effect said cutting.

The holding means 102 comprises a manually operable 7 clamping or gripping mechanism comprising a control handle 106 which is operable to move between a material clamped or gripped position and a material released position.

Holding means 102 comprises a friction device 108, the main function of which is to provide a controlled level of friction resisting movement of the holding means 12 between its clamped or gripped position and its released position, this friction being additional to that which arises from the mechanism of holding means 102 needed to achieve such movement thereof.

Adjusting means 110 is provided for friction device 108 to adjust the level of friction provided and comprises a spring device to increase the friction effect, which spring device 112 s varied by a screw device 114, as will be more fully described below.

Turning now to Fig 3, this shows details of the friction device 108 and the adjusting means 110 with its associated spring device 112 and screw device 114.

Handle 106 is not shown in Fig 3 but operates a crank 116 having a boss 118 located in an opening 120 in a block 122 attached to a control rod 124 which operates the holding means 102.

A friction pad 126 is positioned for face-to-face contact with the corresponding face of block 122.

The frictional forces between block 122 and friction pad 126 are controlled by pads 128 and an associated assembly 130 of spring washers 132, guide pins 134 and grub screws 136 providing for fine adjustment of the functional forces.

In use, the frictional forces are set at just that level needed for fine control of an article to be cut, as described above.

8

Claims (1)

1 A method of indicating the line of cut of a cutting machine for board or card or other sheet materials comprising:- a) providing a cutting machine comprising cutting means to produce a line of cut and structure extending lengthwise of said line of cut to provide a guiding and/or clamping and/or other function in relation to said cutting means; b) providing an indicator element comprising a material which is cuttable by said cutting means; c) providing attachment means for said indicator element whereby it is attachable to and detachable from said structure so as to extend across said line of cut; and d) said method comprising the step of attaching said indicator element to said structure and causing said cutting means to cut said indicator element to produce an indicator edge; and e) using said cut indicator edge in a subsequent cutting operation to indicate the line of cut to be produced by the cutting machine in an article to be cut.

2 A method of indicating the line of cut of a cutting machine characterised by attaching a cuttable indicator element to a cutting machine, cutting an indicator edge on said indicator element, and using said indicator edge in a subsequent cutting operation.

3 A method according to claim 1 or claim 2 characterised by said step of attaching said indicator element comprising using an adhesive band on said indicator element.

9 4 An indicator element adapted for use in a method according to claim 2.

A method of indicating the line of cut of a cutting machine substantially as described herein with reference to the accompanying drawings.

6 An indicator for indicating the line of cut of a cutting machine substantially as described herein with reference to the accompanying drawings.

7 Apparatus for cutting card and/or board and/or other sheet materials comprising:- a) holding means for a sheet of material to be cut and adapted to hold same while it is cut to size; b) cutting means to effect said cutting; c) said holding means comprising a manually operable clamping or gripping mechanism comprising a control handle operable to move between a material-clamped or gripped position and a material-released position; characterised by d) said holding means comprising a friction device, the main function of said friction device being to provide a controlled level of friction resisting movement of said clamping or gripping mechanism between its clamped or gripped position and its released position, which friction is additional to that arising from the mechanism needed to achieve said movement of said mechanism between said positions.

8 Apparatus for cutting card and/or board and/or other sheet materials wherein holding means for said material to be cut comprises a friction device providing a controlled level of friction which is additional to that of said holding means itself.

9 Apparatus according to claim 6 or claim 7 characterised by means for adjusting the friction provided by said friction device.

Apparatus for cutting card and/or board and/or other sheet material substantially as described herein with reference to the accompanying drawings.