On a print bar of a page-wide array ink-jet printer, a plurality of printheads are usually disposed in side-by-side relation, each of which is generally arranged to be consumer-replaceable. An electronics connection is required between the printer (the print bar) and the print head. At the same time, the print head requires a fluid connection to transport air and/or printing fluid, such as ink, to the print head. The print head fires the ink at a print media according to a pattern electronically communicated to it through the electronics connection.
An example within the scope of the present disclosure is described hereinafter with reference to the drawings, in which:
In a page-wide array ink-jet printer, the position of the print head relative to the print bar must be known so that the ink is directed accurately by the print head. The print bar and print head generally have datum surfaces that, once engaged, accurately determine the position of the print head, both positionally in three-dimensions, as well as angularly in three axes.
If the print heads are each considered to be essentially cubic in form, they have almost all sides already in use for different functions: their bottom surface has the printhead nozzles and is employed for firing ink at the paper or material to be printed on; the sides of the print heads are closely adjacent other print heads; their back is employed for attachment to the print bar; their front for attachment of auxiliary systems (or to accommodate an adjacent parallel print bar if there are more than one of them); and their top for user replacement. There is no side that is obviously free for electronics connection.
A latching mechanism may be used to retain the print head in place. The latching mechanism is designed to protect fragile connections that are designed to be made by linear movements, for example between first and second members that are pivoted together. The invention is as defined in the claims.
With reference to the drawings, a page-wide array printer may have a first member in the form of a printer bar 10 across its width and on which are mounted a plurality of printer head modules 12, also referred to herein as print heads. The modules effect the printing onto paper moving underneath the modules. They have ink nozzles and electronic components to control the ejection of ink from the nozzles. To reduce customer maintenance costs, the print head module may be intended to be a replaceable consumable, which means it has to offer a satisfying customer experience when replacing it. However, there are three requirements of the print head modules and their relation with the printer bar. A first is that the print heads are accurately positioned on the bar, both in terms of position in three-dimensional space, and also angularly about the three orthogonal axes. Otherwise the printer may not print accurately. The second is that there are fluid connections between the printer and the modules, for the transport of ink and air to the print heads. And thirdly there are electrical connections so that the print instructions can be communicated from the printer to the modules.
For the first purpose, the printer bar 10 and the modules 12 have mutually engaging datum faces (not shown in the drawings but schematically illustrated in
For the second purpose, the printer bar and print head module are each provided with mutually engaging fluid connectors. These may be arranged to connect and seal by relative movement between the printer bar and print head in a linear direction. Furthermore, the fluid connector on the printer bar may include a valve, so that fluid in the conduit leading to the connector does not leak out when a module is being changed. The valve may be a check valve, which is automatically disengaged from a seat when the connection between the respective connectors is made. However, other means of connecting fluid conduits to the print head may be feasible.
For the third purpose, the printer bar and print head module are each provided with mutually engaging electrical connectors. These may comprise a Peripheral Component Interconnect Express (PCIe) edge connector, which can be made and broken by relative movement between the printer bar and print head in a linear direction.
Thus, turning to
The latching system 14 is the mechanism responsible for ensuring a correct connection between the print head module and the printer. This function includes the electrical (signal and power), fluidic (ink and air) and mechanical (forces) interaction.
In a single bar page wide array printer with a row of several print head modules this function becomes even more critical, as the failure of any of these connections may cause a highly visible defect on the one-pass printing mode. The arrangement illustrated and described herein allows an optimal use of the real estate available on a page wide array print bar in order to ensure a reliable and easy-to-use latching system.
Turning to
Referring specifically to
Turning to
The eye 42 is formed on a block-unlock element 44. The block-unlock 44 is arranged to displace a block 46, against spring bias 48, so that latch member 38 can move rightwardly (in the direction of the arrows H in
Electrical interface between the latch 14 and the print head 12 takes place through a vertical PCIe connection 60. Fluidic interface is built through vertical fluid interconnects 70, including a primer valve 80 in the platform 32.
Platform 32 may be approximately guided for vertical movement by guides 90 in the body 30 of the latch 14. The platform is urged by springs 92 in the direction of the arrow V (when the latch 14 is in the lockable position shown in
The platform is held with the springs compressed by the handle 34 when it is in its open position. A lever 96 is pivoted in the handle 34 intermediate its ends 34a,b. The other end of the lever 96 is pivoted in a push bar 98 that slides in the body 30 in a horizontal direction (arrows H). At each end of the push bar is a Scott-Russel link 100a,b having three ends, one end (A) pivoted in the push bar, one end (B) pivoted in the body 30 and the third end C pivoted on the platform 32. Link 100AC is solid, whereas arm 100B is pivoted at 97 to link 100AC intermediate its ends. The effect of the links 100a,b is that horizontal movement of the push bar 98 is translated into vertical movement of the platform 32 with high gearing or leverage, so that a large movement of the handle 34 results in a small movement of the platform. This means that the springs 92 can be relatively strong without significant effort being expended in turning the handle 34.
When the latch is in the lockable position (as shown in
The fluid connection 70 between the latch 14 and the print head may comprise only an air connection, including an electrically operated pump 80 in the platform 32. In that event, check valve 79 may be omitted. Air may be supplied on occasion to the print head to assist cleaning of the print jets. Ink connections may instead be provided directly between the print bar 10 and print head 12.
Once both electrical and fluid connections have been made, stud faces 110A,B (optionally four pairs of them) on the platform 32 and print head 12 abut one another and when the handle 34 is fully closed, the full force of the springs 92 are applied against the print head 12 securely maintaining it in full engagement with its datum system 22. For this purpose, an element 99 of lost motion may be provided between the end C of the links 100a,b and the platform 32. Indeed, an element of lost motion may be provided at any point in the connection between the handle 34 and the platform 32 to accommodate tolerance in the engagement between the platform and print head, which may be caused by variations in the fit of the print head in the receptor 20 or any of its dimensions. The handle 34 may be provided with a clip to hold it snugly in a closed position in the latch.
Thus, the mechanism translates the rotation done by the user through the handle 34 into a vertical movement of the floating platform, allowing the three connections mentioned above to be made substantially simultaneously.
Referring to
It is for this reason that the block 46 (described above) is provided. It prevents the handle 34 from being closed unless the latch is in its lockable position. It might be noted that, in the absence of the block 46, the latch could not necessarily pivot to its lockable position with the handle 34 being in its closed position. This would likely be prevented by the latch member 38 colliding with the element 44 forming the eye 42.
Nevertheless, this would potentially damage the eye 42, or rather the component in which it was formed, and/or the latch member 38, bearing in mind the mass of the latch 14 and the leverage that mass has at the lock area (38/44), for example if the latch was dropped when at a 45 degree angle to the horizontal, the forces generated on the latch member and eye component could be substantial and damaging. This could be circumvented by, for example, providing the latch member with a ramp so that the latch member was displaced on closing of the latch, but the present arrangement is preferred because, even if the latch member did not prevent the latch from closing to its lockable position at some speed, the latch, or its connections 60,80 could potentially be damaged if the print head was not properly positioned in the receptor 20.
Consequently, the arrangement is such that the latch 14, from being locked closed in the lockable position shown in
Now, should the latch be dropped from the position shown, for example, in
Turning to
In
Electrical connections from the main body of the printer, carried in the printer bar 10, to the latch 14, may comprise wires that are flexed when the latch pivots about its hinge 16. However, a possible alternative arrangement comprises contacts 116 (see
An alternative arrangement of the platform is feasible where push bar 98 is pivoted to modified solid Scott-Russel links 100a,b and where the latch has circular slots formed in its body 30 in which slide pivot pins of the links. The other ends of the links 100a,b may be pivoted in a dish plate (not shown), whereby horizontal movement of the push bar is translated into vertical movement of the dish plate.
The dish plate can mount the springs 92, rather than the body 30. In this arrangement, when the handle 34 is open, the springs 92 are uncompressed. When the handle is closed and the platform lowered, the springs are only compressed when further lowering of the platform 32 is prevented by contact between the stud faces 110A,B. However, with this arrangement a detent or other lock arrangement is needed to retain the handle in its closed position on the latch and maximise the bias applied to the platform 32. For this purpose a tension spring may be provided between lugs on the lever 96 and on the extension 34c of the handle 34, whereby a bistable arrangement may be provided. In and intermediate position of the handle 34, the tension spring urges the lever to its fully open position. On closing the handle 34, not only is spring 201 extended, but also springs 92 are in this embodiment compressed. However, on passing a cusp position when the axis 36 of rotation of the handle is aligned with lugs 201a,b, then the tension spring can work against springs 92. Because of the gearing/leverage provided by the arrangement of the links 100a,b, push bar 98 and lever 96, the tension spring can be arranged to overcome the springs 92 and retain the handle 34 in its closed position.
Throughout the description and claims of this specification, the words “comprise” and “contain” and variations of them mean “including but not limited to”, and they are not intended to (and do not) exclude other moieties, additives, components, integers or steps. Throughout the description and claims of this specification, the singular encompasses the plural unless the context otherwise requires. In particular, where the indefinite article is used, the specification is to be understood as contemplating plurality as well as singularity, unless the context requires otherwise.
Features, integers, characteristics, compounds, chemical moieties or groups described in conjunction with a particular aspect, embodiment or example of the invention are to be understood to be applicable to any other aspect, embodiment or example described herein unless incompatible therewith. All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive. The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed.
The reader's attention is directed to all papers and documents which are filed concurrently with or previous to this specification in connection with this application and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.
Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.
Filing Document | Filing Date | Country | Kind |
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PCT/EP2014/061879 | 6/6/2014 | WO | 00 |