Device for cutting cardboard and like materials

Abstract

 A cutting machine for cutting card, board or the like has a base board, a clamp bar extending across the base board and a cutter head slidingly mounted on the clamp bar. Bearing arrangements for the cutting head provide lateral guidance by interengagement of tapering bearing surfaces on the cutter head and the clamp bar. Polymeric tapering bearing elements on the cutter head have bearing surfaces at their ends separated by a relieved region. The relieved region is fixed. Adjusters act on the end bearing areas to take up clearances and provide the requisite level of adjustment by flexing the end portions of one the bearing elements. A calibration system for stop or other gauges on the cutting machine provides both measurement and calibration scales and associated indicators which both adjust when calibration is effected whereby the extent of such calibration movement is automatically indicated, enabling accurately reproducible offset for under or over-cut to be provided.

Description

[0001] This invention relates to machines for cutting card, board and the like materials. Such machines are used, for example, by picture framers, designers, artists, photographers and the like. Among the uses of such machines are the reduction of large sheets of card to smaller sizes and the cutting of apertures therein, whether with bevelled or square-cut edges. Machines of this kind will be referred to, herein and in the claims, as cutting machines of the kind set forth. It is to be understood that this definition is not to be limited to the provision of bevel cutting or other features which may be needed for particular applications falling within the uses mentioned above. Machines of the kind set forth above may include a base board to support card, board and the like to be cut, together with a clamp bar extending across the base board to clamp the materials to be cut. A cutter head may be mounted on the cutter head for lengthwise sliding movement with respect thereto to cut the materials. Some aspects of the invention also relate to other material treatment or positioning or measurement machines, particularly those having an extruded slideway on which a slider or slidehead is slidable.

[0002] There is disclosed in our prior patents US-A-4 941 380 and GB-A-2 215 654 a cutting machine of the kind set forth in which the cutter head is mounted on the clamp bar for lengthwise sliding movement by means of a projecting wedge member on the cutter head and a complementary wedge-shaped slot on the clamp bar to receive same. Additional bearing surfaces are provided by generally flat and upwardly/downwardly facing surfaces on the clamp bar and the clamp bar head. Additionally, sliding locating means is also provided.

[0003] While the cutter head guidance and bearing system as disclosed in the above-mentioned GB 654 specification has much to commend it and has been commercially successful, we have identified a need for further technical improvements notably in relation to simplifying and reducing the number of components produced for these functions, and to improve the system for lateral and longitudinal guidance while avoiding the possibility of unacceptable tolerances and backlash and to take account of the fact that the guideway (or clamp bar), which usually is manufactured as an aluminium extrusion, does not present to the guide member (or cutter head) a completely straight lengthwise plan view profile. The existence of imperfections in the linearity of the clamp bar/guideway leads to occasional corresponding imperfections in the free sliding movement of the cutter head.

[0004] A further aspect of the invention relates to providing improvements in relation to the system disclosed in our prior patents concerning calibration of the stop and other gauge systems for the cutter, whereby the cutter is set for a pre-determined location and length of cut in relation to the sheet material to be cut. We have identified a need for improvements in relation to the existing system for calibration of the stops and other guides so that these are easy to use and capable of offsetting user errors and capable of accommodating error-feedback data and of maintaining a setting once set correctly. Also, there is a need to be able to adapt for and accommodate the effect of bevel cuts produced when the cutter acts non-vertically, such bevel cuts being affected in terms of their dimensions by the thickness of the board or other material being cut.

SLIDEWAY BEARINGS

[0005] An object of a first aspect of the present invention (relating to Slideway Bearings) is to provide a cutting machine of the kind set forth providing improvements in relation to one or more of the aspects thereof discussed above concerning guidance and support for the cutter head, and/or improvements generally therein.

[0006] According to this first aspect of the invention (relating to Slideway Bearings) there is provided a cutting machine of the kind set forth as defined in claims 14 to 18 and 19 to 27 of the accompanying claims.

[0007] In one embodiment of this aspect of the invention there are provided co-operating guide means on the clamp bar and the cutter comprising a lengthwise-extending guideway on the clamp bar and a guide member on the cutter head. The guideway and guide member have complementary tapering profiles providing bearing surfaces. These tapering surfaces on the guideway and the guide member comprise at least one flexible bearing element mounted so that at least a portion thereof is capable of being flexed towards its co-operating bearing surface for adjustment purposes. In the embodiment, the portion which is capable of being flexed comprises an end portion of the bearing element, indeed both end portions of the bearing element are flexible and the portion therebetween is fixedly mounted. The bearing element is formed of a polymeric material whereby its flexibility enables it to provide a corresponding adjustment function in a very sinmple manner by means merely of the provision of adjustment screws.

[0008] The feature of the flexibility of the bearing element arising from its polymeric construction and its associated fixed mounting at a location spaced from the flexible portion enables the bearing element to provide for very simple adjustment of the bearing itself merely by provision of corresponding adjustment screws, while nevertheless offering a highly; effective bearing system capable of accommodating tolerances introduced by the extrusion manufacturing process in combination with the provision of very adequate bearing surface areas for relatively long bearing life.

[0009] Also in an embodiment of the invention there are provided cooperating guide means on the clamp bar and the cutter head comprising a lengthwise extending guideway on the clamp bar and a guide member on the cutter head, the guideway and the guide member having complementary profiles. These profiles provide lateral guidance of the cutter head and are disposed so that loading the cutter head in a cutting direction tends to caused reduced loading of the bearing surfaces provided by the complementary tapering profiles. In other words, in the embodiment, the downward hand loading of the cutter head by the user is in a direction such that the tapering profiles are urged in a direction reducing their face-to-face loading. The main bearing surface resisting the downward loading on the cutter head is, in the embodiment, provided by simply face-to-face contact of generally vertically disposed bearing surfaces directed directly below. The tapering and laterally-guiding bearing surfaces are disposed on opposite sides of the slideway.

[0010] In addition, in the embodiments, and this feature is by way of complement to the above-described disposition of the tapering bearing surfaces, there is provided adjustment means to adjust at least one of the tapered bearing surfaces to adjust the loading of that bearing surface. In the embodiment, simply screw threaded adjustment means is provided for this purpose. It can now be seen that such adjustment complements the feature of the disposition of the bearing surfaces, whereby in use the entire downward load on the cutter head is slideingly resisted by the cutter head main (and horizontal) bearing surfaces, while the laterally-guiding bearing surfaces can be nicely adjusted so as to maintain free sliding contact without any backlash which would allow for irregularities in the resultant cutting line in use.

[0011] An additional feature of the described embodiments relates to the features whereby the cutter head lateral guidance system is able to accommodate and tolerate those irregularities in linearity of the extruded clamp bar which arise from its extrusion-type manufacture. Thus in the embodiments, the bearing elements for providing lateral guidance of the cutter head are formed with a relieved region separating lengthwise-spaced bearing areas so that continuous sliding bearing contact with the clamp bar (or guideway) is not required. In simple terms, the relieved region is able to accommodate the non-uniform portion of the clamp bar whereby the latter passes smoothly between the bearing areas and, again uniformity of the cutting line is ensured with an absence of discontinuities.

[0012] A further feature of the embodiments concerns a simple method for adjustment of the bearing system lateral guidance for the cutter head. It is only necessary to adjust the bearing element at one side of the guideway and not at both sides. For this purpose, that bearing element has attachment means securing it to the cutter head in its central region, while leaving its end regions (which actually make sliding contact with the guideway, at each side of the central relieved region) free to be adjusted by simple screw threaded means. Thus, the relevant one of the bearing elements is centrally mounted in its relieved region and is provided with simple screw threaded adjusters for its end bearing regions, which adjust and readily take up the level of adjustment needed under cutting loads incurred during use.

[0013] Likewise in the embodiment the generally truncated triangular profile of the bearing elements (whereby they have parallel base and upper surfaces) enables them to provide both the lateral guidance and the vertical load bearing functions simultaneously at the requisite laterally spaced locations, thereby achieving a further simplification in function and construction.

BEARING RELIEF

[0014] A further aspect of the invention provides a cutting machine of the kind set forth as defined in claims 28 to 32 of the accompanying claims, and in embodiments of this aspect of the invention described below there are provided relieved portions in the tapering bearing surfaces of the guideway on the clamp bar and guide member on the cutter head whereby the relieved portion is capable of accommodating a degree of mismatch of the tapered profiles arising from, for example, tolerances introduced during manufacture by extrusion. The relieved portion allows a degree of, effectively, angular movement of the main sliding sub-assemblies of the apparatus whereby bearing surfaces which (due to angular mismatch) might otherwise make effectively almost line contact can come into proper face-to-face contact across at least a substantial portion of their intended operating width.

STOPGAUGE CALIBRATION SYSTEM

[0015] Turning to the second aspect of the present invention, relating to the system for calibration of the cutter stops and other gauges, the requirements for such a system have been identified above and in accordance with this aspect of the present invention there is provided a cutting machine and/or a calibration machine or device therefor, as defined in claims 1 to 13 of the accompanying claims.

[0016] In an embodiment of this aspect of the present invention there is provided a calibration device for a stop or other gauge on the cutting machine where an indicator and a measurement scale adjust relative to each other so as to adjustably indicate the value of a dimension selected for the cutting machine. Manual adjustment means is adapted to adjust the relative positions of the indicator and the scale to permit selective compensation or offset for detected errors in the resultant cut dimension produced by the cutting machine, and the calibration device comprises calibration indication means whereby a measure is provided of the extent of the compensation or offset provided frcm a predetermined or nominal zero position.

[0017] By providing calibration indication means which effects associated relative movement between a calibration scale and an indicator therefor so as to indicate the extent of the calibration movement, there is provided the advantage of enabling in a very simple and straightforward way a measure to be obtained of the extent of calibration effected. This is of practical significance when a machine of the cutting kind is adjusted so as to compensate for a detected undercut or overcut produced when commencing a planned cutting production run. If it is found that a first adjustment or calibration of the cutting device does not produce the exact result required, it is at a minimum desirable and sometimes essential to know the extent of the previous adjustment so that a suitable correction can be made, whether by way of increase or decrease of the adjusted cut dimension. Similar factors arise in relation to use of a given cutting machine by different persons whose ocular and other attributes lead to readily-determined, but different calibration settings for their own accurate use of the equipment. Such settings can be readily returned to in the embodiments of the invention.

[0018] Likwise, in relation to the cutting of board and other materials with bevelled edges, there is a complicating factor in the accurate setting of the cutting machine arising from the actual thickness of the board to be cut, whereby the angle of the bevelled cut and the thickness of the material cut significantly change the effective resultant dimensions of a given cut. This leads to a need for a corresponding calibration of the equipment in a readily reproducible way. The embodiments of the invention meet this need by enabling numerical recordal of the corresponding calibration settings accordingly.

[0019] In the embodiments of the invention the arrangement is such that the adjustment device which effects calibration movements is arranged to effect simultaneous adjusting movement both of a calibration extent-indicating member and of a corresponding calibration member for the measurement scale. These are formed as a common movable structure having two limbs disposed generally parallel to each other and likewise parallel to the calibration and measurement scales. As a result, an extremely simple finger-operated adjustment device can be provided with a compression spring to effect frictional resistence to unintended adjustment once a setting has been reached.

[0020] Embodiments of the invention will now be described by way of example with reference to the accompanying drawings in which:

Figs 1, 2 and 3 show aspects of the cutting machine disclosed in our prior UK patent GB-A-2 215 654, Fig 1 showing a general perspective view of the machine, Fig 2 showing a section through the cutter head taken in the plane II-II in Fig 1 and Fig 3 showing a close-up perspective view of the cutter head in use;

Figs 4 to 8 show an alternative cutter head and clamp bar arrangement for the cutting machine of Figs 1 to 3 in accordance with an embodiment of the invention;

Fig 4 shows a section through the cutter head and clamp bar generally similar to that of Fig 2;

Fig 4A shows a portion of Fig 4 on a larger scale;

Fig 5 shows further details of Fig 4, but the section being taken with an opposite viewing direction and showing the fasteners employed for mounting the bearing elements on the cutter head;

Fig 6 shows, on a larger scale and in perspective, one of the bearing elements of Figs 4 and 5;

Figs 7 and 8 show elevation views of the cutter head of Fig 5 from the front and rear, as indicted by arrows VII and VIII in Fig 5, and showing the positional locations of the mounting and adjustment fasteners for the bearing elements.

PRIOR ART

[0021] AS shown in Fig 1 of the drawings, a machine 10 for cutting card, board and like materials as used by picture framers, artists, designers, photographers etc comprises a base board 12 to support the card, board and the like to be cut. A clamp bar 14 extends upon the base board to clamp materials to be cut. Mounting means is provided for the clamp bar and comprises a pair of spaced arms 16, 18 between which the clamp bar is connected. Means is provided for raising and lowering the clamp bar to allow insertion of the materials to be cut. This means permits at least the ends of the arms 16, 18 to be raised and provides a torsion bar 20 interconnecting the ends of the arms 16, 18 for manual lifting by the user, and a pair of support legs not seen in the drawings, whereby the bar 20 can be held in a raised position for inserting of card under the clamp bar. The arms of 16, 18 comprise leaf springs 22, 24 which permit the tension bar 20 to be raised by simple bending of the springs. This provides a very durable construction. A cutter head 26 is mounted on clamp bar 14 for lengthwise sliding movement with respect thereto, to cut the card or other materials. Stop means, not shown in detail, is provided for a user accurately to cut card to size and to cut apertures, for example aperture 28 shown in card 30, during use.

[0022] Fig 3 shows cutter head 26 in use, with the hand 32 of the user actuating, by means of thumb and index finger a pivotal cutter element 34 having a blade 36, pivotal movement of an axe is generally at right angles to the surface 38 as seen in Fig 2 enables the user to bring head 36 in and out of its cutting position.

[0023] Turning now to Fig 2, it will be seen that clamp bar 14 is shown together with a sliding block 40 forming part of cutter head 26. Block 40 provides a mount forming part of element 34 carrying blade 36. Blade 36 engages the material to e cut by projecting slightly beyond the edge 42 of clamp bar 14. Blade 36 and cutter element 34 are not shown in Fig 2. Clamp bar 14 is formed with recesses 44 and 46 to mount scales for measurement purposes during use. Profiled recesses 48, 50 and 52 in sliding block 40 provide mounting for further structures of the cutting machine not relevant for purposes.

[0024] As shown in Fig 2, cutter head 26 is located on clamp bar 14 by means of a sliding locater 54 mounted on block 40 by means of a fastener 56 and an intermediate spring element 58. Locater 54 is generally of upwardly tapering form and is received in a corresponding channel 56 formed in clamp bar 14. Fastener 56 is adjusted so that the locater freely slides in channel 56.

[0025] In order to support cutter head 26 for free sliding movement lengthwise of clamp bar 14, there is provided co-operating guide means on the clamp bar and on the cutter head, the guide means on the clamp bar and on the cutter head comprising a lengthwise extending guideway on the clamp bar and a guide member on the cutter head, the guideway and the guide member having complementary tapering profiles. As shown in Fig 2, guideway 60 is in the form of a wedge shaped slot formed in clamp bar 14, and guide member 62 is in the form of a projecting wedge member received in the slot. These cooperating guide elements provide sliding location of the cutter head 26 relative to the clamp bar.

[0026] In addition to the guideway 60 and guide member 62 there are also provided interengaging sliding support surfaces 64, 66 which serve also to resist downwardly directed loads in use.

[0027] Before use, the locater 54 is adjusted to provide sliding movement while adequately locating cutter head 26. After that no further adjustment is needed. Surfaces 64, 66 and the engaging surfaces of the guideway and guide member 60 and 62 are provided with a low friction material such as UHMW Polyfine to promote free sliding movement.

SLIDEWAY BEARINGS

[0028] Turning now to the embodiment of the present invention, this is shown in Figs 4 onwards and will now be described on the basis of representing a modification of the prior art system described above in relation to figs 1 to 3. Such modification involves the use of a modified clamp bar and a modified cutter head. In this embodiment of the invention, reference numerals will commence at 100.

[0029] Therefore, as shown in Fig 4, machine 100 for cutting card, board and like materials comprises a clamp bar 102 having a cutter head 104 mounted thereon and corresponding to cutter head 26. Details of the construction of cutter head 104 from cutter head 26 differ in respects which are unimportant for the purpose of the present invention and will therefore not be described. The important differences of the present embodiment from cutter lead 26 relate to the systems provided for location and for lengthwise sliding movement and lateral guidance and for the provision of means to slidingly resist vertical and related loads.

[0030] In the system on Figs 1 to 3, cutter head 26 is located with respect to clamp bar 14 by sliding locater 54 mounted on block 40. Lateral guidance is provided by complementary tapering profiles provided on guideway 60 in the form of a wedge shaped slot, and a corresponding guide member 62 in the form of a projecting wedge member received in the slot. Bearing surfaces 64 and 66 slidingly support the cutter head.

[0031] In the present embodiment, the entire system for providing not only location but also lateral guidance and bearing support against downward loads during use, is provided by a guideway 106 on clamp bar 102 and cooperating bearing elements 108, 110 provided on cutter head 104.

[0032] As shown in Fig 4, guideway 106 has outwardly facing and upwardly-diverging guideway surfaces 112. Bearing elements 108, 110 have respective complementary, inwardly-facing and upwardly-diverging bearing surfaces indicated in Fig 5 and 114 and 116 but which are more fully described below with reference to Fig 6.

[0033] Bearing elements 108, 110 are received in correspondingly-rectangularly profiled recesses formed in cutter head 104 so that their bearing surfaces 114 and 116 are placed for sliding engagement with the corresponding bearing surfaces 112 of clamp bar 102. The bearing elements are secured in position by fasteners 118 having heads 120 received in countersunk apertures 122. Fasteners 118 have threaded shanks 134 which screw-threadily cooperate with threaded bores provided at the inner portion of apertures 122.

[0034] Bearing elements 118, 110 extend lengthwise the full lengthwise extent cutter head of 104 and likewise the recesses in which they are mounted. These recesses are provided at the inner side faces of a generally channel-shaped portion 126 of the cutter head defined by flanges 128 provided on the cutter head.

[0035] Fig 4A shows on a larger scale a detail of the construction of the guideway 106 which can also be seen in Fig 104, notably the provision of the relieved portions 112A in bearing surfaces 112 to accommodate a degree of mismatch of the tapered profile arising from, for example, tolerances introduced during manfacture by extrusion of the guideway. The relieved portions extend across only a portion of the width of the relevant bearing surfaces, such portions being less than half of that width and indeed slightly less than one quarter thereof. The relieved portions permit the toleration of more mismatch than otherwise would be the case without an unacceptable loss of bearing surface area.

[0036] Turning now to the details shown in Fig 6 concerning the bearing elements 108,110 we mention first that the bearing element material itself may be chosen according to the specific characteristics required and according to the predispositions of the user. A typical example might be a UHM (Ultra high molecular weight) Polyolefin, or PTFE or a derivative thereof or any other polymer having suitable friction and wear characterises whether with or without a filler or other materials.

[0037] As shown in Fig 6, the inner bearing face of each of the bearing elements 108, 110 has a central relieved portion 132 which is relieved to the extent of a few millimetres in depth in order to ensure that the end bearing regions 134 provide the entire inclined and inwardly facing bearing surfaces for the bearing element. Each of the bearing elements is similarly constructed in this regard. Fig 6 does not show the generally wedge-shaped profile of the bearing element very clearly. This can be readily seen in Figs 4 and 5.

[0038] Apertures 122 are formed in the central relieved region 132. Thus, the bearing elements are mounted and supported in their central region and their bearing regions are capable of being deflected for bearing adjustment reasons as explained below.

[0039] In this latter, regard as show in Fig 7, cutter head 104 is provided with additional screw threaded apertures 136 to receive corresponding threaded fasteners 138 for adjustment purposes. The adjusters 138 have suitable driving formations such as slots or sockets whereby there can be threaded inwards or outwards for engagement of their inner ends (not shown) with the rear side of end bearing regions 134 of bearing elements 108, 110 so as to adjust these towards and away from the corresponding tapering services 122 on guideway 106. Provisions for such adjustment is only made at one side of cutter head 104 namely with bearing element 108, since this is sufficient to make all required adjustments.

[0040] Other details of cutter head 104 seen in Figs 4 to 8 are not described since they do not concern the present invention.

[0041] In use, after installation of the cutter head, the clearances of bearing element 118,110 are adjusted by means of fasteners 138 in order to provide free running but backlash-free guided sliding movement of the cutter head.

STOPGAUGE CALIBRATION

[0042] Turning now to the embodiment of Figs 9, 10 and 11 - 13, there is shown an end stop device in the form of a start-of-cut assembly suitable for use with a cutting machine of the kind shown in Fig 1 of the drawings. Such an assembly defines the location at which the cutter head is caused to stop in its lengthwise travel along the guideway at that end of its travel which represents the start of cut. The assembly is slidably mounted on the clamp bar 14, (see Fig 1). Although not shown in fig 1, the assembly would be mounted at a location to the right of cutter head 26 in Fig 1 so that the cutting travel of the cutter head extends from the stop assembly in a leftwards and downwards direction, as seen in Fig 1, towards the other stop which is indicated at 200.

[0043] Stop assembly 202 of Figs 9 to 13 incorporates a calibration device 204 which may also be used in the other stop 200, and likewise in other adjustable measurement devices on the cutting machine 10 including the so-called mat guide 206 (with sliding adjusters 208,210) and the limit stop 212 for presetting mat sizes.

[0044] Broadly speaking, the calibration device 202 is applicable to the several identified locations in cutting machine 10 at which the position of a stop device or like mechanical element depends for the accuracy of its setting on user-perceived mechanical setting data on a main setting scale, the interpretation of which will vary, to some extent from one user to another. Accordingly, by provision of a resettable calibration device the calibration setting which any particular user finds convenient and which leads to accurate cutting can be readily achieved and returned-to in accordance with the features to be described below.

[0045] As shown in Figs 9 to 13, calibration device 204 comprises a stop member in the form of an arm 214 projecting laterally from a slidable caliper 216 received on a lengthwise extending scale 218 carried on clamp bar 14 (not shown in Figs 9 to 13). An indicator 220 mounted on caliper 216 co-operates with measurement scale 218 to indicate the adjusted position of caliper 216. A setting knob 222 having a screw-threaded shank 224 co-operates with scale 218 and caliper 216 to fix the caliper in a selected adjusted position.

[0046] Arm 214 has a leaf-spring-mounted extension 226 having a projecting contact 228 to rest on the upper surface of the sheet material being cut.

[0047] Calibration device 204 further comprises manual adjustment means 230 adapted to adjust the relative positions of indicator 220 and measurement scale 218 to permit selective compensation or offset for detecting errors in the resultant cut dimension produced by the cutting machine. Calibration indication means 232 is provided to indicate the extent of calibration selected from a pre-determined nominally zero position. Calibration indication means 232 comprises a calibration scale 234 and an associated indicator 236.

[0048] As can be clearly seen in Figs 12 and 13, calibration scale 234 and indicators 220 for measurement scale 218 are formed as a one-piece generally U-shaped structure having corresponding twin limbs which is slidably received in corresponding grooves seen best in Fig 10 whereby it is lengthwise-adjustable at a location above measurement scale 218 and in a direction generally parallel thereto. An adjustment knob 238 having a corresponding screw-threaded shank 240 on which is received a coiled compression spring 242 serves to provide an adjustment function for indicator 220 and calibration scale 234. Indicia 244 and an associated adjustment direction arrow 246 serve no identify the direction of rotation of knob 238 for positive or negative calibration adjustment from a nominal zero position seen in Fig 9.

[0049] It can now be readily understood that adjustment of the calibration device 204 by means of adjustment knob 238 effects simultaneous adjustment both of indicator 220 and of the calibration scale 234, since these are a one-piece construction which is slidingly mounted on caliper 216. As scale 234 is moved in the negative direction (towards the bottom of the page in Fig 9) so the calibration scale 234 is likewise moved simultaneously downwards so that indicators 236 then indicate a setting in the upper (and negative) portion of scale 234. Any chosen setting is readily retained by the frictional effect of spring 242 on the threaded shank 240 of adjustment knob 238.

[0050] In use, if it is found that a given cut is unacceptable in terms of length at the start of cutting, then the appropriate plus or minus adjustment is made by means of calibration adjustment knob 238 followed by setting knob 222 - which latter enables the actual stop itself then to be correctly positioned.

[0051] It will be understood that this aspect of the present invention is not limited to use in relation to devices involving a cut-limiting stop but may, for example, be used for calibration of the setting scale for other dimensional aspects of the cutting procedure including the positioning of board or other materials to be cut with reference to the apparatus as such.

Claims

1. A cutting machine of the kind comprising a base, a clamp bar, and a cutter head slidable along the clamp bar, and a stop device to define a cut limit for said cutter head and which is also slidable along said clamp bar, said cutting machine comprising a calibration device for said stop device, wherein an indicator and a cut-measurement scale adjust relative to each other in order to adjustably indicate the location of a stop position defined by said stop device, and said calibration device comprising manual adjustment means adapted to adjust the relative positions of said indicator and said stop device to permit selective compensation or offset for detected errors in the resultant cut dimension produced by said machine, said calibration device further comprising a calibration scale mounted on said stop device together with an associated indicator which automatically adjust relative to each other on said adjustment of said relative positions of said stop device and said indicator, whereby divisions on said calibration scale provide a measure of the extent of the compensation or offset provided from a pre-determined position.

2. A machine according to claim 1 characterised by said calibration indication means being adapted to effect simultaneous associated relative movement between said calibration scale and said indicator therefor when said measurement scale and said indicator therefor are adjusted.

3. A machine according to claim 2 characterised by said calibration indication means comprising a movable calibration extent-indicating member and an associated adjustment device to effect movement thereof, and said adjustment device being adapted to effect simultaneous adjusting movement of a corresponding calibration member for said measurement scale.

4. A machine according to claim 3 characterised by said calibration extent-indicating member and said corresponding calibration member for said measurement scale being formed as a common movable structure.

5. A machine according to claim 3 or claim 4 characterised by said calibration extent-indicating member and said corresponding calibration member for said measurement scale comprising a pointer for one of said scales and a scale itself for the other thereof.

6. A machine according to claim 4 characeterised by said common movable structure comprising a generally two-limbed structure with said limbs disposed one generally parallel to the other, and said scales being likewise disposed one generally parallel to the other.

7. A machine according to any one of the preceding claims characterised by said scales being calibrated in common units.

8. A machine according to any one of the preceding claims characterised by said measurement scale being fixed relative to its indicator which is movable with a stop or gauge member, said measurement indicator being thus position-adjustable relative to said stop to effect said calibration.

9. A machine according to claim 8 characterised by said stop or gauge member being connected to a slide or carriage which is position-adjustable lengthwise of said measurement scale and which also carries said calibration indicating means.

10. A cutting machine of the kind set forth, comprising

a) a base board to support card, board or the like to be cut;

b) a clamp bar extending across the base board to clamp materials to be cut;

c) a cutter head mounted on the clamp bar for lengthwise sliding movement with respect thereto to cut said materials;

d) co-operating guide means on the clamp bar and the cutter head and comprising a lengthwise-extending guideway on the clamp bar and a guide member on the cutter head, said guideway and guide member having complementary tapering profiles providing bearing surface;

characterised in that:

e) said complementary tapering surfaces on said guideway and said guide member comprising at least one flexible bearing element mounted so that at least a portion thereof is capable of being flexed towards its co-operating bearing surfaces for adjustment purposes and

f) adjustment means being provided to adjust said at least one portion of said bearing element to adjust the bearing effect provided thereby.

11. A cutting or other material treatment or positioning or measurement machine comprising complementary bearing profiles on a slideway and slider member such as a clamp bar and a cutter head and characterised by at least one flexible bearing element therefor mounted so that at least a portion thereof is capable of being flexed towards its co-operating bearing surface for adjustment purposes.

12. A machine according to claim 11 characterised by said portion of said flexible bearing element which is capable of being flexed comprises an end portion thereof.

13. A machine according to claim 12 characterised by said portion of said bearing element which is capable of being flexed comprises both end portions of said bearing element, and said bearing element being fixedly mounted between said end portions.

14. A machine according to any one of claims 10 to 13 characterised by said bearing element comprising polymeric material.

15. A cutting machine of the kind set forth, comprising:

a) a base board to support card, board or the like to be cut;

b) a clamp bar extending across the base board to clamp materials to be cut;

c) a cutter head mounted on the clamp bar for lengthwise sliding movement with respect thereto to cut said materials;

d) co-operating guide means on the clamp bar and the cutter head and comprising a lengthwise-extending guideway on the clamp bar and a guide member on the cutter head, said guideway and guide member having complementary tapering profiles;

characterised in that

e) said complementary tapering surfaces on said guideway and said guide member providing lateral guidance of said cutter head and being disposed so that downward loading in a cutting direction tends to reduce loading of the bearing surfaces provided by said complementary tapering profiles;
and

f) adjustment means being provided to adjust at least one of said bearing surfaces to adjust the loading of said bearing surface.

16. A cutting or other material treatment or positioning or measurement machine comprising complementary tapering bearing profiles on a slideway and slider member such as a clamp bar and a cutter head characterised by said profiles being disposed so that the cutting loads tend to reduce bearing loads and adjustment means being provided for the bearing surfaces.

17. A cutting machine according to claim 15 or 16 characterised by said complementary tapering surfaces being downwardly tapering and said loading in a cutting direction also being in a downward direction in use.

18. A cutting machine according to claim 17 characterised by said guideway comprising an extrusion and said adjustable bearing surface comprising bearing areas spaced apart in a lengthwise direction of said guideway and having a relieved region between them to accommodate extrusion irregularities in said guideway.

19. A cutting machine according to claim 18 characterised by said adjustment means being arranged to adjust said spaced bearing areas.

20. A cutting machine according to claim 19 characterised by said adjustment means being arranged to adjust said spaced bearing areas by means of a screw threaded adjusted positioned to deflect at least one of said spaced bearing areas towards said guideway.

21. A cutting machine according to any one of the preceding claims characterised by said bearing surfaces on said guideway and said guide member comprising a pair of opposed polymeric bearing elements defining said guide member bearing surfaces, and the opposite tapering surfaces of said guideway for sliding engagement therewith defining said guideway bearing surfaces, and said polymeric bearing elements having said tapering bearing surfaces at their inner faces and also having generally upwardly and downwardly-facing bearing surfaces forming main bearing surfaces to take downwardly-directed loads applied during cutting.

22. A cutting machine according to claim 20 characterised by said cutter head being adapted to apply said downwardly-directed loads to said guide member generally vertically through said polymeric bearing elements.

23. A cutter head for cutting materials of the kind described wherein generally wedge-shaped bearing elements are adapted to locate the cutter head both vertically and laterally, and to provide bearing surfaces for generally downwardly-directed loads.

24. A cutting machine of the kind set forth, comprising:

a) a base board to support card, board or the like to be cut;

b) a clamp bar extending across the base board to clamp materials to be cut;

c) a cutter head mounted on the clamp bar for lengthwise sliding movement with respect thereto to cut said materials;

d) co-operating guide means on the clamp bar and the cutter head and comprising a lengthwise-extending guideway on the clamp bar and a guide member on the cutter head, said guideway and guide member having complementary tapering profiles providing bearing surfaces;

characterised in that:

e) said complementary tapering surfaces on said guideway and said guide member including a relieved portion extending lengthwise thereof and capable of accommodating a degree of mismatch of the tapered profile thereof arising from, for example, tolerances introduced during manufacture by extrusion of one of said co-operating guide means.

25. A machine according to claim 24 characterised by said relieved portion being formed in said guideway on said clamp bar.

26. A machine according to claim 24 or claim 25 characterised by said relieved portion extending across less than half of the width of said co-operating guide means, and preferably across less than one quarter of the width thereof.

Drawing