Printer and cutter frame

Abstract

 Frame (60) for a dot matrix printer and/or a cutter for cutting a medium printed by such printer, on which frame are mountable a guideway for a movable carriage and a rotatable shaft for feeding the medium to the movable carriage such that the guideway and the shaft are parallel when mounted, wherein the frame comprises a base member (61) made of sheet metal and substantially extending over the length of the frame, a pair of first members (62) made of sheet metal and connected to the base member, wherein each of the first members comprises means (622) for mounting a bearing thereon for supporting the shaft. The frame is characterised in that it comprises at least one second member (63, 64) made of sheet metal, arranged transverse to the base member (61) and interposed between the first members (62). The second member (63, 64) comprises means (631) for mounting a bearing for additionally supporting the shaft at an intermediate location between the bearing locations of the first members. Apparatuses incorporating such frames are provided as well.

Description

[0001] The present invention is related to frames for dot matrix printers and/or for cutters co-operating with such printers. Those devices comprise a single-axis linear guideway for a movable carriage (for printing and/or cutting) and a rotatable shaft for feeding the medium. The present invention is particularly related to frames for such devices, made of sheet metal.

[0002] Larger ink jet printers, such as those used for industrial scale printing, having effective print widths of 1000 mm or larger, are presently assembled on a base support of extruded aluminium having rectangular cross section. The base support provides for the required stability and stiffness of the printer. The extruded profiles are subsequently machined in order to provide for the fastening locations for assembly thereon of the various components, such as the linear guideway with movable carriage for the print head, the medium feed shaft, etc. Such components are mounted on supports, which are fastened to the base support. After mounting of the supports and possibly of the components, these need to be aligned and/or adjusted in order to compensate for possible inaccuracies of the base support due to e.g. bendings, or torsions thereof. This is a tedious and time-consuming activity.

[0003] Furthermore, printers of different size (capable of printing media of different size) require base support profiles of different cross sectional size. Not only are such profiles expensive in cost, machining operations prior to and during assembly involve quite some labour and time.

[0004] For (standalone) cutters arranged for cutting media printed on the abovementioned printers and for printer/cutter combinations, the same reasoning applies, as their structure and assembly is largely analogous to such printers.

[0005] The use of sheet metal frames for a printer of different kind (based on an imaging drum) and of smaller dimensions is known from DE 10104048. The frame is made up of interconnecting pieces with tongues intersecting in matching slits. Document GB 2182288 discloses a print device frame produced by press-forming sheet metal. Such frames however would not be advantageous for the large span printers referred to in the present invention, as additional adjustments and/or alignments would nevertheless be required.

[0006] It is therefore an aim of the present invention to provide a (large size) dot matrix printer and/or cutter which is easier to produce and less expensive to manufacture. It is an aim of the present invention to provide a (large size) dot matrix printer and/or cutter which is easier to assemble, such that lengthy and tedious alignments and/or adjustments of the various components are obviated.

[0007] This is achieved by providing a frame for such dot matrix printers and/or cutters, as set out in the appended claims, which due to its construction is inherently accurate, and on which the various components, notably a medium feed shaft and a linear guideway for a movable carriage can be mounted without requiring further alignments.

[0008] According to an aspect of the invention, there is therefore provided a frame for a dot matrix printer, for a cutter for cutting a medium printed by such printer, or for a combination of both. A linear guideway for a movable carriage and a rotatable shaft for feeding the medium are mountable on the frame, such that the linear guideway and the shaft are parallel when mounted. The rotatable shaft is arranged to feed the medium to the movable carriage.

[0009] The frame is advantageously essentially made of sheet metal parts. It comprises a base member made of sheet metal and extending over the length of the frame and a pair of first members made of sheet metal. The first members are preferably arranged transverse to the base member. They can be arranged at opposite ends of the base member, so as to form outer sidewalls of the frame. Each of the first members comprises means for mounting a bearing thereon configured for supporting the shaft.

[0010] The longitudinal direction of the frame (or of the printer/cutter) refers to the direction of the linear guideway and the medium feed shaft and is also referred to as the span. It refers to the direction transverse to the direction of medium feed. In terms of use (of a dot matrix printer), the longitudinal direction refers to the direction of the fast scan effected by a print head and relating to a translation of the print head along the linear guideway.

[0011] An element transverse to the base member refers to the element being aligned in a direction substantially perpendicular to the longitudinal direction. Hence the element is aligned in the direction in which the medium is fed through the printer, in use.

[0012] According to the invention, the frame comprises at least one, but preferably a plurality of second members made of sheet metal. The second member(s) are arranged transverse to the base member. The second members are interposed between the first members, preferably at regularly spaced intervals. Each of the second members comprises means for mounting a bearing configured for additionally supporting the shaft at intermediate locations between the bearing locations of the first members. Each second member hence comprises provisions for the mounting of an additional bearing/support to the bearing arranged to be mounted on the first members. Each second member is arranged to receive a separate bearing.

[0013] Frames of the invention preferably comprise at least two, more preferably at least four, most preferably at least six second members. Each of these provides additional bearing support location for the medium feed shaft.

[0014] The sheet metal parts (members) are simply and cheap to produce, such as by laser cutting out of a (single) sheet metal blank. Moreover, they can be produced in a single stage having included all necessary joining and fastening provisions (holes, slits, lips, etc.) for mounting the components. They can be produced with high accuracy and repeatability. By aligning the sheet metal members at the time of interconnecting them, such as with the aid of tooling equipment, a frame can be manufactured wherein the necessary mounting supports for the components are integrated, which moreover has the required accuracy since it is already aligned. The apparatus can be assembled without further adjustment.

[0015] The additional intermediate supports for the medium feed shaft prevent sagging of the shaft, which could otherwise result in cockling of the medium. Hence, frames of the present invention incorporate automatic shaft alignment by sheet metal members. The medium feed shaft is automatically aligned when it is mounted on the frame. No further adjustments are necessary.

[0016] Furthermore, the frame can easily be provided with additional sheet metal members, in order to achieve the required stability and stiffness.

[0017] Also, with a same structural design, frames of different sizes can be produced with increased flexibility. It suffices to provide base members of different lengths, and adjust the number of second transverse members.

[0018] Further advantageous aspects of the invention are presented in the dependent claims.

[0019] Preferably, the frame comprises for each second member a bearing for additionally supporting the shaft mounted on the second member(s). For ease of manufacture, it is advantageous to mount the bearings prior to joining the sheet metal frame members.

[0020] Preferably, the bearing for additionally supporting the shaft is formed of at least one roller, preferably at least two rollers.

[0021] Preferably, the frame comprises one or more third members, made of sheet metal and extending between the first members so as to engage with the second member(s). The third members are preferably oriented transverse to the second member(s). They preferably interconnect with the second member(s).

[0022] Preferably, at least the second member and the third members are so arranged as to define a plurality of chambers. The chambers are in fluid connection with a location where the medium is arranged to pass, preferably corresponding to the location covered by the movable carriage (printing and/or cutting location). The chambers further comprise an outlet, such that they are in fluid connection with the ambient. Each chamber is preferably arranged such that evacuation of air from the chamber allows, in use, to bias the medium towards a target. The target can be a support for the medium, such as a grid, being in fluid connection with the chamber and preferably arranged to be mounted on the second member(s).

[0023] Preferably, at least one second member forms a separating wall between adjacent chambers, so as to prevent substantial flow of air from one chamber to the adjacent chamber when in use.

[0024] Preferably, the second member forming the separating wall is arranged at a position corresponding, in use, to the lateral edge of printable and/or cuttable media having a width smaller than the maximal width that can be accommodated in the frame. By so doing, and since the chambers are separate, it is possible to evacuate air only from those chambers which are effectively covered by said media.

[0025] Preferably, each of the first members comprises means for mounting the linear guideway thereon. The advantage here is that alignment between the medium feed shaft and the guideway is facilitated, as it is integrated into by a single member.

[0026] Preferably, the members are fastened to each other by welding, more preferably by laser beam welding.

[0027] Preferably, the interdistance between the first members is at least 1000 mm, preferably at least 1500 mm.

[0028] According to a second aspect of the invention, there is provided a dot matrix printer, a cutter for cutting a printed medium and a combination of cutter and dot matrix printer. Any one of the above comprises a frame according to the invention.

[0029] Preferably, any one of the above apparatuses comprises a frame forming chambers for air evacuation as indicated above and further comprises air evacuation means for each chamber, actuatable independently of each other in function of the size of the medium that is used.

Brief Description of the Drawings

[0030] Figure 1 represents a cross section of a printer according to the present invention.

[0031] Figure 2 represents a cross section of the frame of the printer of figure 1 (minor details may be different).

[0032] Figure 3A represents a perspective view of the frame of figure 2. Figure 3B represents an enlarged portion of figure 3A as indicated.

[0033] Figure 4 represents a perspective view of the base member of the frame of figure 3A.

[0034] Figure 5 represents a plan view of a first transverse member of the frame of fig. 3A.

[0035] Figures 6 and 7 represent plan views of second (intermediate) transverse members of the frame of figure 3A.

[0036] Figure 8 represents a perspective view of the second transverse members mounted on the base member.

[0037] Figure 9 represents a plan view of a longitudinal member (rear member) of the frame of figure 3A.

[0038] Figure 10A represents a perspective view of the insertion of the longitudinal member of figure 9 onto the frame portion of figure 8. Figure 10B represents the disposition after mounting.

[0039] Figure 11 represents a plan view of a longitudinal member (front member) of the frame of figure 3A.

[0040] Figure 12A represents a perspective view of the insertion of the longitudinal member of figure 11 onto the frame portion of figure 10B. Figure 12B represents the disposition after mounting.

[0041] Figure 13A represents a perspective view of a frame of a cutter according to the present invention. Figure 13B represents an enlarged detail as indicated.

[0042] Figure 14 represents a cross section of the frame of figure 13A.

[0043] Figures 15 and 16 represent plan views of second transverse members of the frame of figure 13A.

[0044] Figure 17 represents a perspective view of the base member and the second transverse members mounted thereon.

[0045] Figure 18 represents a plan view of a longitudinal member (rear member) of the frame of figure 13A.

[0046] Figure 19A represents a perspective view of the insertion of the longitudinal member of figure 18 onto the frame portion of figure 17. Figure 19B represents the disposition after mounting. Figure 19C represents an enlarged portion as indicated.

[0047] Figure 20 represents a plan view of a longitudinal member (front member) of the frame of figure 13A.

[0048] Figure 21A represents a perspective view of the insertion of the longitudinal member of figure 18 onto the frame portion of figure 17. Figure 21B represents the disposition after mounting.

[0049] Figure 22 represents a plan view of a first transverse member of the frame of figure 13A.

Detailed Description of the Invention

[0050] The present invention relates to frames for dot matrix printers and for (single-axis) cutters, capable of co-operating with such printers. The dot matrix printers are preferably ink jet printers. Frames of the invention are also suitable for combined devices, integrating a dot matrix printer and a cutter into a single apparatus.

[0051] The dot matrix printers and the cutters referred to in the present invention all comprise a (linear) guideway for a movable carriage. The carriage is arranged to comprise either a print head (in case of a printer), or a cutting device (in case of a cutter). The guideway is single-axis. The carriage hence is movable along a single axis only relative to the frame.

[0052] A combined printer-cutter device can either comprise a single movable carriage, comprising both the print head and the cutting device, or it can comprise two independently movable carriages. The two independently movable carriages can be provided either on a same guideway, or on two separate guideways arranged in parallel.

[0053] Dot matrix printers and cutters referred to in the present invention furthermore comprise a rotatable shaft for feeding (transporting) the medium to be printed and/or cut to the location for printing and/or cutting. The shaft is arranged parallel to the guideway. It is rotatable on its axis, relative to the frame. The shaft's axis hence is arranged parallel to the guideway. The shaft is located upstream of the print head and/or cutting device.

[0054] In order to feed the medium, the outer surface of the shaft can at least partly be made of a material having a high friction coefficient on the media for use in apparatuses of the invention. Such a high friction material, such as rubber, or grit material, can be provided as a covering on the shaft. The high friction material is arranged to prevent slip between the medium and the shaft, so that the medium is fed to (typically underneath) the movable carriage at a controllable, predetermined speed. The shaft is preferably driven (actuated).

[0055] In order to further prevent slip between the shaft and the medium, a roller can be provided at an end of a lever arm, which is biased towards the shaft. The roller and the shaft are arranged to act as a pinch, so as to press the medium onto the shaft. The roller and the shaft are hence so arranged that the medium passes between the two, when the device is in use. The roller can suitably be made or covered with a high friction material, such as rubber or grit material.

[0056] Figure 1 shows a cross section of an ink jet printer 1 according to the present invention. The printer 1 comprises a frame 10 on which is mounted a linear guideway 20 comprising tracks 21 on which rollers (bearings) 22 of a movable carriage 23 are seated. A print head 24 is provided on the carriage 23.

[0057] An optional gutter 25 can be provided underneath the print head 24 in case the printer is arranged for printing permeable media, such as textiles. The gutter is hence arranged to collect excess ink permeating through such media. For impermeable media, the gutter is replaced by a flat grid which supports the medium at the location 2 of printing. The media hence are arranged to be transported between the print head 24 and the gutter 25 / flat grid.

[0058] A rotatable shaft 30 is supported on the frame 10. The shaft 30 is arranged for transporting a medium (not shown) to the location for printing 2, situated underneath the print head 24. The shaft 30 can be made of metal (e.g. steel) and is preferably covered at regular intervals along it with a layer of grit material. A better grip on the medium can thereby be obtained. The shaft can be complemented with a roller 31 provided at an end of a lever arm 32. The lever arm 32 is pivotable on a fulcrum 33. At the other side of fulcrum 33, relative to the roller 31, a spring 34 biases the roller towards the shaft 30. Roller 31 and shaft 30 hence form a pinch, in between which a medium is arranged to be squeezed and transported to the printing location 2.

[0059] A cutter device as referred to in the present invention has substantially a same structure as the printer of figure 1, the greatest difference being that the carriage bears a cutting device instead of a print head.

[0060] Except for the frame 10, the other components mentioned hereinabove are well known to the skilled person. The present invention hence proposes improvements at the level of the structure which supports both the guideway and the medium feed shaft. A frame is provided, which is substantially made out of sheet metal parts, which are interconnected so as to form a rigid and stiff structure. The frame allows easy manufacture, reducing costs and labour time substantially. Furthermore, the frame allows easy assembly and mounting of the various components, notably the abovementioned guideway and feed shaft. That is to say, the frame is constructionally so arranged that alignment and adjustment of the latter components on the frame is obviated. Hence, once mounted, the components are automatically correctly positioned. No further adjustment is required.

[0061] The sheet metal parts making up the frame can easily be accurately machined, such as by laser cutting. By correctly positioning the sheet metal parts when interconnecting them to form the frame, a frame can be obtained which is accurate and which allows to give the sheet metal parts added functionality, such as a toleranced (and hence accurate) seating for the guideway and the shaft and additional bearing support for the shaft as well.

[0062] Examples of frames according to the invention are now described. Figure 2 shows a cross section of the frame 10 for the printer of figure 1. Figure 3A shows a perspective view of the frame 10, a detail of which is shown enlarged in figure 3B.

[0063] The frame comprises a base member 11, which extends over the span (length) of the printer (see fig. 4). The base member 11 is made of sheet metal. The base member can be suitably folded, or can comprise a suitably folded support 111, providing for enhanced bending resistance (stiffness).

[0064] At both the ends of the base member 11 (ends delimiting the span of the printer/cutter, hence the longitudinal ends) and attached thereto are provided first members 12. The first members 12 are made of sheet metal (see fig. 5). Since, in the present embodiment they are arranged transversely to the base member 11, they are referred to as (first) transverse members 12. The first transverse members 12 can be considered as outer sidewalls of the frame 10.

[0065] Referring to figure 2, the first transverse members 12 comprise a support 121 for the guideway 20 and a support 122 for the medium feed shaft 30. The supports can be seatings, conveniently accurately machined within predefined tolerance limits. By correctly positioning the first transverse members 12 relative to the base member 11 at the stage of interconnection, such seatings do not require further adjustment or alignment at the time of assembly of the guideway 20 and/or medium feed shaft 30.

[0066] The support 121 for the guideway 20 can comprise (or be formed of) a couple of angularly disposed edges 123 and 124 of the first transverse member 12. The edges can be cut in the sheet metal of the first transverse member. These edges are arranged to form seatings of corresponding faces of the guideway. Making the guideway 20 abut against the two edges 123 and 124 ensures correct alignment thereof.

[0067] The support 122 for the medium feed shaft 30 can preferably be provided in the same first member 12, or alternatively in a separate one, arranged in alignment with the former one. In the example depicted in figure 2, the first transverse member 12 conveniently comprises supports for both the guideway 20 and the shaft 30.

[0068] The support 122 for the medium feed shaft can be formed of a provision for mounting a bearing for the shaft, such as one or more mounting holes. Accurate production of the transverse member, such as by laser cutting and correct alignment of the sheet metal members at the time of joining them to form the frame can allow correct mounting of the bearings on the frame, without the need of additional alignment and/or adjustment.

[0069] As a result, the medium feed shaft 30 is correctly aligned (such as being parallel to the guideway, within tolerance limits) at the moment it is mounted onto the frame.

[0070] The location of the first transverse member 12 and of the support 122 for the medium feed shaft 30 is preferably such, that the medium feed shaft 30 is arranged upstream of the printing location 2.

[0071] Driving means (not shown) for the medium feed shaft 30 can additionally be provided, either coupled to, or separate of one of the first transverse members 12. The medium feed shaft 30 can extend past the first transverse members 12, to the location where the driving means are provided. An additional bearing (or bushing) can be provided at that location.

[0072] It is to be noticed that in general the first member 12 need not extend transverse to the base member 11, neither need it form an outer sidewall. For example, one of the first members 12 can be formed of a support for the driving means for the rotatable shaft 30, which can have a bearing or bushing integrated.

[0073] In addition to the first members 12, frames of the invention comprise second transverse members 13 (see fig. 6) and 14 (see fig. 7), provided interposed between the first members 12. The second transverse members 13 and 14 are made of sheet metal. They are arranged transverse to the base member 11 and preferably parallel to the first transverse members. They are preferably, but need not be, identical to each other. The second transverse members can suitably be spaced at regular intervals, as shown in figure 8, illustrating their disposition on the base member 11.

[0074] The first and the second transverse members are preferably arranged perpendicular to the base member.

[0075] According to the invention, the second transverse members 13, 14 comprise provisions for mounting a bearing 40 (see fig. 1). These provisions can be formed of one or more mounting holes 131. The bearings 40 are arranged to support the medium feed shaft 30 at intermediate locations between the supports (bearings) at the first transverse members 12 and in addition thereto.

[0076] Hence, at suitably selected locations in between the first transverse members (the outer sidewalls of the frame), additional support/bearing can be provided for the medium feed shaft 30. As with the first transverse members, accuracy in construction of the frame can allow for immediate correct positioning of the mounting provisions 131 for such support/bearing 40, without requiring post-mounting alignment and/or adjustment.

[0077] The intermediate supports/bearings 40 for the medium feed shaft 30 prevent sagging of the shaft. This is particularly an issue in printers and cutters having a large span, such as those accommodating media with widths of 1000 mm and larger. Sagging of the medium feed shaft can lead to cockling of the medium and to variations in distance between the print head and the medium, causing a degradation of the print quality and/or possible problems with cutting.

[0078] The provision of multiple support locations for the medium feed shaft enables to reduce the diameter of such shafts, which can be a further cost reduction.

[0079] The bearings intended for mounting on the second transverse members (for both printer and cutter) and possibly those for mounting on the first members 12, can be formed of one or more rollers 40. They can be slide bearings (bushings), such as made of plastic. The bearings can be so arranged that the medium feed shaft is clippable in the bearings. The medium feed shaft can suitably be free of any friction increasing material, such as rubber or grit, on the outer surface at the location of the supports/bearings.

[0080] An additional functionality of the second transverse members 13, 14 is to increase the rigidity and resistance against bending of the frame structure.

[0081] For example, the frame 10 can comprise members 15, 16 (see fig. 3A) extending longitudinally along the base member 11. The longitudinal members are made of sheet metal and preferably extend over the entire span between the first transverse members 12. Furthermore, the longitudinal members 15 (see fig. 9), 16 (see fig. 11) interconnect with some or all of the second transverse members 13, 14 as shown in figures 10A-B and 12A-B.

[0082] The interconnections between the different sheet metal members can be made in first instance by providing suitable lips 125, 132, 142, configured for engagement in corresponding slits 112, 113, 114, such as is the case between the transverse members 12, 13, 14 and the base member 11. Another possibility is by providing corresponding (partial) cut outs 133, 143, 144 and 151, 161 in the interconnecting members for engagement into one another.

[0083] After correct positioning of the sheet metal members, such as in a tooling device, the sheet metal members can suitably be fastened to each other. Preferred fastening techniques are by welding, in particular laser beam welding. The fastening should provide rigid joining/fixation between the sheet metal members so as to form a rigid and stiff frame 10.

[0084] The bearings 40 can be provided on the second transverse members 13, 14, and possibly on the first transverse members 12 as well prior to the assembly of the frame 10. This can ease post-processing and can decrease manufacturing lead times.

[0085] The second transverse members 14 can comprise a space 145 for the mounting of a gutter 25 for the collection of ink in case of printers arranged for printing permeable media (see fig. 7). The gutter extends underneath the print head, all along the length over which the print head is arranged to print in a single scan.

[0086] In case of printers that are arranged to print on impermeable media, the gutter-space 145 is closed on some of the second transverse members 14 (e.g. by suitable baffles). The first and second members 12 and 14, together with the longitudinal members 15 and 16 and with the base member 11 form three separate chambers 101, 102 and 103 from which air can be evacuated independently of each other (see fig. 3A). This can be effected by providing fans (not shown) in the chambers for evacuating air through apertures 162, 163 and 164 in the longitudinal member 16. Tubes (not shown) between the apertures in the longitudinal member 16 and corresponding apertures 115, 116 and 117 in the base member 11 provide for outletting the air underneath the printer.

[0087] The chambers are separated from each other by the second transverse members 14. The chambers 101-103 can be further closed by the medium (when the printer is in use). The medium can for example close the chamber at the top.

[0088] Each of the chambers 101, 102 and 103 advantageously has its individual air evacuation means. Air evacuation is used to force the medium on a (flat) grid or support provided on the second transverse members 14, so as to ensure a constant distance between the medium and the print head. The air evacuation means can be actuated in function of the medium size. When media of smaller size are printed, so that one or more of the chambers 101-103 are left uncovered, the air evacuation means (e.g. the fan) of such chambers can be disabled. This allows to save energy.

[0089] Hence, in addition to the intermediate support for the medium feed shaft, the second transverse members also allow compartmenting the frame, so as to ensure flexible and smooth operation when accommodating media of different widths.

[0090] The number of air evacuation chambers can easily be adapted by providing more or less second transverse members 14. The number of air evacuation chambers can easily be made dependent on the size of the frame (printer or cutter size).

[0091] Printers of the invention can be combined with a medium cutter. In such case, means can be provided in order to open the baffles provided in the spaces 145 of the transverse members 14 between the air evacuation chambers 101-103 when a cutting device is arranged to perform a cutting action on the medium.

[0092] Aspects of the invention are equally related to frames for cutters and to cutters comprising such frames. The cutters are apparatuses arranged for cutting media, along a single axis, after printing. Such cutters can comprise means for identifying information relating to the printed image (e.g. a bar code) and for collecting cutting data therefor.

[0093] Figures 13 and 14 represent a frame 60 of a cutter apparatus, having characteristics analogous to those of the printer frame indicated hereinabove.

[0094] The frame 60 comprises a base member 61 made of sheet metal. The base member 61 extends substantially over the length of the frame 60. At opposite lateral ends (lengthwise) of the base member 61 are provided a pair of first transverse members 62 (see fig. 22), arranged transversely to the base member 61. They are so arranged as to form the outer sidewalls of the frame 60.

[0095] The first transverse members 62 can comprise a support 621 for a (linear) guideway for a movable carriage. The movable carriage is arranged to comprise (hold) the cutting device.

[0096] The support 621 for the guideway can comprise, or consist of, angularly disposed edges 623, 624 cut in the sheet metal and against which the guideway is made to abut when mounted on the frame.

[0097] The first transverse members 62 comprise mounting provisions (supports 622) for a bearing for a rotatable shaft arranged to feed the medium to be cut to (underneath) the cutting device (the movable carriage). Such a shaft can have same characteristics as the medium feed shaft of a printer as indicated hereinabove.

[0098] Both the support 621 for the guideway and the support 622 for the bearing of the medium feed shaft are advantageously integrated in the same first transverse members 62. Precision cutting (e.g. by laser cutting or punching) of the first transverse members 62 out of a sheet metal blank can allow for precise interpositioning between the two.

[0099] The supports 622 for the medium feed shaft bearing are preferably so located in the first transverse members 62 that the medium feed shaft is arranged upstream of the cutting location 4, so as to enable the feeding of media to the cutting location 4. The cutting location 4 can be defined by the position of the carriage movable on the guideway.

[0100] Interposed between the first transverse members 62 are provided second transverse members 63, 64 (see fig. 15 and 16). The second transverse members 63, 64 are arranged transverse to the base member 61 and are made of sheet metal as well. The second transverse members 63, 64 are preferably arranged at regularly spaced intervals, between the first transverse members 62.

[0101] The second transverse members 63, 64 are preferably arranged perpendicular to the base member 61. The first transverse members 62 are advantageously arranged perpendicular to the base member 62 as well. The first and second transverse members are preferably arranged parallel to each other.

[0102] Each of the second transverse members 63, 64 comprises mounting provisions 631 for a bearing arranged to additionally support the medium feed shaft. Hence, additional bearing support for the medium feed shaft is provided at intermediate locations between the bearing/support locations at the first transverse members 62. Mounting provisions 631 can be one or more mounting holes.

[0103] The space between the first transverse members 62 can be partitioned in separate compartments or chambers 601, 602, 603 for the evacuation of air. The compartments are conveniently separated by the second transverse members 63. In use, a wall of these chambers can be formed by the medium itself. Each chamber comprises an outlet 604, 605, 606 for the air. Air evacuation means, such as a fan, can be mounted on the frame for each chamber individually, e.g. at the outlets.

[0104] The chambers 601-603 are further delimited by two longitudinal members 65 and 66, made of sheet metal and extending between the first transverse members 62. The longitudinal members 65 and 66 interconnect with the second transverse members 63 and 64 and are arranged perpendicular with the base member. The longitudinal members 65 and 66 advantageously provide for increased stiffness and rigidity of the frame against bending and torsion.

[0105] The air evacuated from the chambers 601-603 is in fact sucked from underneath the medium at the location 4 intended for cutting. Such cutting location 4 is preferably delimited by a gutter-like passage 67, which is advantageously made of sheet metal. Apertures 662 (see fig. 20) provide a passage for the air from the gutter to the air evacuation chambers 601-603.

[0106] The sheet metal members of the cutter frame 60 are advantageously interconnected by lips 632 for engagement in corresponding slits 611 and/or by corresponding cut outs 633, 634 and 651, 661 engaging with each other. This can provide for an initial interconnection at the assembly stage, such as for alignment in a tooling device. Figures 17, 19A-C and 21A-B illustrate steps in the assembly of the frame based on the different sheet metal members (base member, first and second transverse member, longitudinal members).

[0107] The sheet metal members are fastened thereafter, such as by screwing, welding, riveting, etc. Welding, in particular laser beam welding, is preferred.

[0108] Frames according to the invention, for ink jet printers and/or cutters, are particularly suitable for accommodating media having a width of 1000 mm or larger, with media widths of at least 1500 mm being preferred and media widths of at least 1650 mm being particularly preferred. Hence, the effective stroke (over which printing and/or cutting can be effected) of the movable carriage mountable on frames of the invention is preferably at least 1000 mm, more preferably at least 1500 mm and most preferably at least 1650 mm.

[0109] The interdistance between the first members 12, 62 is preferably larger than the abovementioned widths.

[0110] Aspects of the printer frame 10 and of the cutter frame 60 can be combined and/or interchanged, where suitable.

[0111] The sheet metal is preferably steel.

[0112] The sheet metal members of frames of the invention advantageously comprise mounting provisions for additional components, such as for the driving means of the medium feed shaft, for the driving means of the movable carriage and for control means for the apparatus (e.g. printed circuit boards).

Claims

1. Frame (10, 60) for a dot matrix printer (1) and/or a cutter for cutting a medium printed by such printer, on which frame are mountable a guideway (20) for a movable carriage (23) and a rotatable shaft (30) for feeding the medium to the movable carriage (23) such that the guideway (20) and the shaft (30) are parallel when mounted, wherein the frame comprises:

- a base member (11, 61) made of sheet metal and substantially extending over the length of the frame,

- a pair of first members (12, 62) made of sheet metal and connected to the base member (11, 61), wherein each of the first members comprises means (122, 622) for mounting a bearing thereon for supporting the shaft (30),
characterised in that the frame (10, 60) comprises at least one second member (13, 14, 63, 64) made of sheet metal, arranged transverse to the base member (11, 61) and interposed between the first members (12, 62), the second member (13, 14, 63, 64) comprising means (131, 631) for mounting a bearing (40) for additionally supporting the shaft (30) at an intermediate location between the bearing locations of the first members (12, 62).

2. Frame of claim 1, wherein each second member (13, 14, 63, 64) comprises a bearing (40) for additionally supporting the shaft mounted thereon.

3. Frame of claim 1 or 2, wherein the bearing (40) for additionally supporting the shaft is formed of at least one roller, preferably at least two rollers.

4. Frame (10, 60) of any one preceding claim, comprising third members (15, 16, 65, 66), made of sheet metal and extending between the first members (12, 62) so as to engage with the second member (13, 14, 63, 64).

5. Frame (10, 60) of claim 4, wherein at least the second member (14, 63) and the third members (15, 16, 65, 66) are so arranged as to define a plurality of chambers (101, 102, 103, 601, 602, 603), the chambers being in fluid connection with a location (2, 4) where the medium is arranged to pass and with the ambient, such that evacuation of air from the chamber allows, in use, to bias the medium towards a target.

6. Frame (10, 60) of claim 5, wherein at least one second member (14, 63) forms a separating wall between adjacent chambers (101, 102, 103, 601, 602, 603), so as to prevent substantial flow of air from one chamber to the adjacent chamber when in use.

7. Frame (10, 60) of claim 6, wherein the second member (14, 63) forming the separating wall is arranged at a position corresponding, in use, to the lateral edge of printable and/or cuttable media having a width smaller than the maximal width that can be accommodated in the frame, so as to enable adjustable evacuation of air only on those parts covered by said media.

8. Frame (10, 60) of any one preceding claim, wherein each of the first members (12, 62) comprises means (121, 621) for mounting the linear guideway (20) thereon.

9. Frame of any one preceding claim, wherein the members are fastened to each other by welding.

10. Frame of any one preceding claim, wherein the interdistance between the first members (12, 62) is at least 1000 mm, preferably at least 1500 mm.

11. Dot matrix printer (1) comprising a frame (10) as in any one preceding claim.

12. Cutter for cutting a printed medium, comprising a frame (60) as in any one claim 1 to 10.

13. Combination of cutter and dot matrix printer comprising a frame as in any one claim 1 to 10.

14. Any one of dot matrix printer, cutter or combination thereof as in claim 11, 12 or 13, comprising the frame of claim 6 or 7, and comprising air evacuation means for each chamber, actuatable independently of each other in function of the size of the medium that is used.

Drawing