Abstract:
A cartridge  10  for a printer  40 , the cartridge  10  including a rigid element  32  which protrudes from the remainder of the cartridge  10  for preventing the cartridge  10  from being filly engaged in the printer  40 . The main part  34  of the element  32  is arranged to be removed by snapping it off to enable the cartridge  10  to be fully engaged in a printer  40  and to open at least one aperture into the cartridge.

Description:
FIELD OF THE INVENTION 
     The invention relates to a cartridge and the combination of a cartridge and a printer. 
     Ink cartridges for printers such as ink jet printers include a delivery aperture, through which ink is withdrawn for printing and one or more breather holes, through which air enters to replace the volume of ink withdrawn, and to prevent a vacuum being created in the cartridge as a result of withdrawal of ink. Cartridges are commonly supplied with a seal over the delivery aperture and a label over the breather hole or holes to prevent the cartridges from leaking in handling before they are inserted into a printer. The seal is pierced by the ink withdrawal needle of the printer when the cartridge is inserted. The label however must be removed before the cartridge is inserted into the printer or ink cannot be withdrawn. This is particularly important in the first use of a printer of the kind where ink is transferred through a pipe from the cartridge to a remote printing head. At its first use, the printer is empty of ink and attempts to draw sufficient ink from the cartridge to fill the pipe and hence reach the printing head. If there is a label still over the breather hole or holes, this will be resisted due to vacuum build-up in the cartridge and the printer can be damaged. 
     SUMMARY OF THE INVENTION 
     According to one aspect of the invention there is provided the combination of a cartridge and a printer, the cartridge including an element preventing the cartridge from being fully engaged in the printer, at least part of the element being arranged to be removed to enable the cartridge to be fully engaged in the printer and to open at least one aperture into the cartridge. 
     The element may be a protruding element and may be rigid. The removal may be by snapping or breaking off at least part of the element. 
     According to another aspect of the invention there is provided a cartridge for a printer, the cartridge including a rigid element at least part of which is arranged to be removed to open at least one aperture into the cartridge. 
     According to a further aspect of the invention, there is provided a cartridge for a printer, the cartridge including an element at least part of which is arranged to be removed by being snapped off to open at least one aperture into the cartridge. 
     According to another aspect of the invention there is provided a cartridge for a printer, the cartridge including an element at least part of which is arranged to be removed by being broken off to open at least one aperture into the cartridge. 
     Preferably, the element is protruding. 
     The or each aperture may be a delivery aperture. In a preferred embodiment the or each aperture is a breather hole. 
     The element may include a connecting part which is connected to the cartridge, the connecting part including at least one projection, the or each projection being received in an aperture of the cartridge. The element may be arranged to be removed so that the or each projection is removed from the or each aperture, but preferably a removable part of the element is removable from the connecting part, and preferably further the or each projection defines a passageway into the aperture so that when the removable part has been removed there is a passageway defined into the cartridge. 
     The or each projection and the or each aperture preferably have complementary surfaces. This increases the surface area of contact and therefore increases the frictional force to ensure that the connecting part is not removed by removal of the removable part. The or each projection and the or each aperture may have polished contact surfaces. This further increases the surface area of contact to increase frictional force. The or each projection and the or each aperture are preferably tapered. In this way the or each projection can be jammed in the or each aperture achieving a tight fit. The taper may be less than 5° and preferably is about 1°. 
     The removable part of the element may extend substantially perpendicularly to the axis of the or each projection. 
     The removable part of the element may lie against a surface of the cartridge, which may be the surface in which the or each aperture is formed, and may extend beyond the surface as a protruding part. The protruding part may lie in a plane substantially perpendicular to the axis of the or each projection. Preferably the extended part extends downwardly from that plane towards the cartridge body. The removable part may include a portion which lies against a second surface of the cartridge. The second surface may be perpendicular to the first surface. The portion which lies against a second surface of the cartridge will act to resist movement in the direction towards the second surface and therefore ensure that removal takes place only in the opposite direction thereby ensuring removal in the desired manner. The removable part may include a portion which lies against a third surface of the cartridge which may be perpendicular to the first and/or second surfaces. The removable part preferably further includes a portion which lies against a fourth surface of the cartridge which may be parallel to one of the other surfaces. In this way, the removal can only take place in the desired direction, as movement in any other direction is resisted by one of the said portions. 
    
    
     BRIEF DESCRIPTION OF DESCRIPTION OF DRAWINGS 
     Three embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, in which: 
     FIG. 1 is a side elevation of a cartridge in a first embodiment of the invention, the cartridge being partially inserted into a printer, only a fragment of the printer being shown, and that fragment in partial cross-section; 
     FIG. 2 is a top plan view of the cartridge of FIG. 1; 
     FIG. 3 is an underneath plan view of an element of the cartridge of FIG. 1; 
     FIG. 4 is a rear elevation of the element of FIG. 3; 
     FIG. 5 is a front elevation of the element of FIG. 3; 
     FIG. 6 is a side elevation in cross-section at A—A of FIG. 4; 
     FIG. 7 is a detail side elevation of the top of the cartridge at B—B in FIG. 2; 
     FIG. 8 is the view of FIG. 7 with part of the element broken away; 
     FIG. 9 is a side elevation of a cartridge in a second embodiment; 
     FIG. 10 is a side elevation in cross-section of the cartridge of FIG. 9; 
     FIG. 11 is the view of FIG. 10 with part of an element of the cartridge broken away; 
     FIG. 12 is a side elevation of the element of the cartridge of the second embodiment; 
     FIG. 13 is a side elevation in cross-section of a cartridge in a third embodiment; 
     FIG. 14 is the view of FIG. 13 with part of an element of the cartridge broken away; 
     FIG. 15 is a fragmentary detail view of the break area of FIG. 14; and, 
     FIG. 16 is an end elevation in cross-section at C—C of FIG.  14 . 
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
     The cartridge  10  of the first embodiment is a generally rectangular box  11  having a top  12 . The cartridge  10  includes three breather holes  18  in the top  12  which are equally spaced along a notional line parallel to and adjacent the rear edge  14  of the cartridge  10 . The top  12  further defines a plurality of fill holes  16 . 
     The top  12  comprises a platelike main body  20  and a plurality of depending hollow bosses  22 ,  24 , aligned with the breather holes  18  and the plurality of fill holes  16  respectively, the fill holes  16  being blocked by ball bearings  28 . The breather holes  18  are axially elongate. The walls  30  defining each breather hole  18  are tapered inwardly downwardly at an angle of about 1° to the axis of the breather hole  18 . The cartridge  10  is made of plastics material. The walls  30  of the breather holes  18  are polished. The cartridge box  11  includes a hollow boss defining an outlet port  31  depending from its bottom surface  29 . 
     An element  32  comprises a main part  34  and three depending hollow projections  36  which are received in the breather holes  18 . The projections  36  are of a complementary tapered shape to the breather holes  18  and have polished outer surfaces  38 . The main part  34  is generally rectangular and tray shaped and lies over the upper surface of the top  12  extending rearwardly past the rear edge  14  of the top  12 . The front edge  42  of the main part  34  terminates just past the forwardmost extent of the projections  36 . The main part  34  is the same width as the top  12 . Two ribs  44  depend from the main part  34  and extend in the front to rear direction of the cartridge  10 . Each rib  44  terminates adjacent the rear wall  46  of the box  11 . 
     A printer  40  includes walls  48 ,  49  defining an upwardly open cartridge receiving space  50 . Extending upwardly into the bottom of the space  50  is an ink withdrawal needle  52  which is connected by a pipe (not shown) to a print head (not shown). 
     In use, the element  32  blocks the breather holes  18  as the main part  34  blocks the ends of the hollow projections  36  which are firmly engaged in the breather holes  18 . If the cartridge  10  is lowered into the cartridge receiving space  50 , the ribs  44  of the element  32  of the cartridge  10  will foul on the top of the rear wall  49  defining space  50  preventing the outlet port  31  of the cartridge  10  from receiving the withdrawal needle  52 . If the cartridge  10  is removed, the protruding rear part  56  of the main part  34  can be grasped and lifted. As the projections  36  are frictionally held, the main part  34  will be broken away with a snap action by the lever force applied. The projections  36  will be left in the breather holes  18  as shown in FIG.  8  and are now unblocked as the result of removal of the main part  34  so that there is a clear passageway through each hollow projection  36  and breather hole  18  into the interior of the cartridge  10 . The cartridge  10  can then be fitted in the printer  40  with the ink withdrawal needle  52  received in the outlet port  31  of the cartridge  10 . 
     The polished outer surfaces  38  of the projections  36  and the walls  30  of the breather holes  18  and their tapered fit ensure that there is a strong frictional force holding the projections  36  into the breather holes  18 . 
     The ribs  44  prevent the main part  34  being levered by the protruding rear part  56  in the downwards direction as shown in the drawings which otherwise would use the rear edge  14  of the top  12  as a fulcrum and the action would therefore tend to lever the projections  36  out of the breather holes  18 . The ribs  44  resist movement in that direction and therefore ensure that the rear part  56  can only be moved in the opposite direction which is the correct direction to break the connection to the projections  36 . 
     The second embodiment is shown in FIGS. 9 to  12 . The second embodiment is similar to the first and only the differences from the first embodiment will be described. The same reference numerals will be used for equivalent features. 
     In the second embodiment the main part  34  is not tray-shaped and the protruding rear part  56  extends downwardly from the remainder of the main part  34  at the rear edge  14  of the top  12  of the cartridge box  11  at an angle of about 20° to the rear wall  46  of the cartridge box  11 . The ribs  44  extend over the length of the rear part  56  and from the rear part  56  to the rear wall  46  of the box  11  and are thus triangular. 
     The element  32  further includes two flanges  58  provided on opposite sides of the main part  34 . Each flange  58  depends from the main part  34  where it lies on the upper surface on the top  12  to closely lie adjacent a side surface  60  of the box  11 , and is also connected to the side edge of the protruding part  56 . 
     In use, the ribs  44  will prevent movement of the main part  34  in the direction towards the rear wall  46  of the box  11 , as in the first embodiment. The flanges  58  will also prevent movement of the main part  34  about a longitudinal axis in the plane of the top surface of the top  12  of the box  11 . The element  32  is thus confined to movement only about an axis parallel to the rear edge  14  of the box  11  and parallel to the line of breather holes  18 . The fact that the protruding or extended rear part  56  is at an angle reduces the risk of the main part  34  being broken off accidentally, while at the same time giving better leverage and an easier manual action when the user does want to break off the main part  34 . It also spaces the outlet port  31  of the cartridge further from the withdrawal needle  52  of the printer  40  on attempted entry of the cartridge  10  into the printer  40 . 
     The third embodiment shown in FIGS. 13 to  16  will now be described. The third embodiment is similar to the second embodiment and only the differences from the second embodiment will be described. The same reference numerals will be used for equivalent features. 
     The top  12  of the cartridge  10  has only the central one of the three breather holes  18  of the other embodiments. The top  12  includes a shallow recess  70  in the upper surface  72  thereof around the breather hole  18 . The main part  34  of the element  32  includes a raised land  74  on its underside  76  which is received in the recess  70 . 
     A longitudinal rib  78  depends from the underside of the top  12  to lie within the cartridge  10  and extends from the rear wall  46  of the box  11  nearly to the nearest fill hole boss  24 . The rib  78  intersects the boss  22  defining the breather hole  18  and there is a small gap in the rib  78  around the end of the breather hole  18  so that the passage of air through the breather hole  18  is not obstructed by the rib  78 . The rib  78  is of substantially constant depth from the rear wall  46  to past the boss  22  and then steadily decreases in depth. A porous member  80  in the form of a sponge is provided in the box  11  in use and is impregnated with ink. 
     In use, the rib  78  keeps the ink impregnated sponge  80  away from the end of the breather hole  18  and this inhibits the entry of ink into the hollow projection  36  and the breather hole  18 . It was found that without the rib  78  ink could be drawn into the hollow projection  36  and the breather hole  18  by capillary action and that removal of the main part  34  could lead to ink “spitting” out of the top of the breather hole  18 . 
     If there should be any leakage of ink from the breather hole  18  then the recess  70  confines the leakage so that the chances of a person handling the cartridge  10  getting ink on their fingers is reduced.