Abstract:
A magnetic sealing cap for dispensing inkjet ink from a bottle into a receptacle. The cap may include two magnetic sealing plates. The cap may also include a ball and ring having a magnetic attraction to each other. The magnetic seal of the invention is reversibly broken by a displacement pin exhibited by the receptacle.

Description:
FIELD OF THE INVENTION 
     The invention relates to the field of inkjet ink receptacles. 
     BACKGROUND OF THE INVENTION 
     Inkjet ink is used often in assembly lines to label products such as packages and magazines. Maintenance of such inkjet printers and replenishment of their ink supply must be done quickly and efficiently so as to minimize adverse affects on progress of the assembly line. Further, handling of inkjet ink is particularly dangerous, since such ink may be toxic and highly staining in the event of spills. 
     Ink for assembly line inkjet printers is often delivered by re-usable ink bottles which feed into inkjet ink receptacles, from which ink is drawn for printing. An example of such an application is illustrated in U.S. Pat. No. 5,343,226, the disclosure of which is incorporated herein by reference. In such an application, it is common to insert the inkjet ink bottle, cap down, into the receptacle. So that the cap need not be removed from the bottle to allow the ink to flow, the receptacle passageway may exhibit a pin which, upon insertion of the cap into the receptacle, depresses a spring-loaded plunger in the cap. The displacement of the plunger unseals a passageway in the cap, allowing the inkjet ink to flow downward from the bottle, through the cap and into the receptacle, from where the inkjet printer may draw the ink. Upon removal of the inkjet ink bottle and cap from the receptacle, the spring-loaded plunger reseals the cap, preventing the ink from flowing out of the bottle. 
     A problem with the spring-loaded plunger caps of the prior art is that springs may break or weaken over time, which is particularly undesirable if the cap is to be re-used many times. The present invention provides an alternative sealing mechanism using magnets. 
     SUMMARY OF THE INVENTION 
     There is disclosed herein an inkjet ink bottle cap including a mechanism for locking the cap in a receptacle, a passageway for receiving a displacement pin upon inserting the cap in a receptacle, and a displaceable magnetic seal. The magnetic seal may comprise a ball and sealing seat having a magnetic attraction to each other, and the ball may be displaced by the displacement pin. The magnetic seal may further comprise two sealable seal plates having a magnetic attraction to each other and one of the two plates fixed to a plunger. The plates may be displaced from each by displacement of the plunger by the pin upon insertion of the cap into the passageway. In any embodiment, the magnetic seal re-seals by magnetic attraction upon removal of the cap from the passageway and, thus, removal of the displacement pin from the cap. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of a cap in accordance with the present invention. 
     FIG. 2 is a side view of the cap of FIG. 1, turned 90° from the view of FIG.  1 . 
     FIG. 3 is a bottom view of the cap of FIG.  1 . 
     FIG. 4 is a top view of the cap of FIG.  1 . 
     FIG. 5 is a cross-sectional view of the cap of FIG. 1, exhibiting an open seal. 
     FIG. 6 is a cross-sectional view of the cap of FIG. 2, exhibiting a closed seal. 
     FIG. 7 is a cross-sectional view of FIG. 5, turned 90°. 
     FIG. 8 is a cross-sectional view of FIG. 6, turned 90°. 
     FIG. 9 is an exploded view of the cap of FIG.  1 . 
     FIG. 10 is a side view of an inkjet ink bottle including an alternative embodiment of a cap in accordance with the present invention. 
     FIG. 11 is a top view of the cap of FIG.  10 . 
     FIG. 12 is a cross-sectional view of the cap of FIG. 10, exhibiting an open seal. 
     FIG. 13 is a cross-sectional view of the cap of FIG. 10, exhibiting a closed seal. 
     FIG. 14 is an exploded view of the cap of FIG.  10 . 
     FIG. 15 is a side view of an adapter. 
     FIG. 16 is a top view of the adapter of FIG.  15 . 
     FIG. 17 is a top and side view of a key. 
     FIG. 18 is a side view of a plug for use with the adapter of FIG.  15 . 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An embodiment of the present invention is illustrated in FIGS. 1-9. Cap  1  has interior threads  3  for affixing the cap  1  to a bottle (not shown). The exterior of the cap  1  exhibits shoulders  5 . Cap  1  may be inserted into a low-tolerance opening and sealed with an o-ring (not shown). Cap  1  exhibits a passageway  7  for receiving a displacement pin (not shown) from the receptacle (not shown). The passageway  7  is sealed by a rubber grommet head  9  of the plunger  11 . Plunger guides  13  and  14  and o-ring  16  stabilize the rubber grommet head  9  and effect sealing when the rubber grommet head  9  is in the sealed position illustrated in FIGS. 6 and 7. The plunger  11  is further stabilized by a plunger sleeve  15 . 
     The plunger  11  is fixed to a first magnetic plate  17 . In the sealed position illustrated in FIGS. 6 and 7, the magnetic attraction between the first magnetic plate  17  and a second magnet plate  19 , fixed to plunger guide  13 , biases the grommet head  9  of plunger  11  against the interior surface of the passageway  7 , sealing the cap  1 . 
     In the unsealed position illustrated in FIGS. 5 and 8, a displacement pin (not shown) from a receptacle presses the rubber grommet head  9  of the plunger  1  away from the interior surface of the passageway  7 , causing the plates  17  and  19  to separate and opening the cap  1  to allow ink to flow through the passageway  7 . Upon removal of cap  1  from the receptacle, and hence removal of the pin (not shown) from the passageway  7 , the magnetic attraction between plates  17  and  19  causes the plates to be drawn together as shown in FIGS. 6 and 7, resealing the passageway  7 . 
     An alternative embodiment of the present invention is illustrated in FIGS. 10-14. Cap  21 , illustrated attached to bottle  23 , exhibits exterior threads  25  for inserting the cap  21  and bottle  23  into a receptacle (not shown) by screwing the cap  21  into receiving threads of a receptacle (not shown). 
     Cap  21  includes a ball cage  27 , a steel ball  29 , first o-ring  31 , second o-ring  33 , plug  35 , flat washer magnet  37 , and passageway  39 . In the sealed position illustrated in FIG. 13, magnetic attraction between steel ball  29  and flat washer magnet  37  biases steel ball  29  against o-ring  33 , sealing passageway  39 . 
     In the unsealed position illustrated in FIG. 12, a displacement pin (not shown) from a receptacle (not shown) presses the steel ball  29  into the ball cage  27  and away from o-ring  33  and flat washer magnet  37 , opening passageway  39  to allow ink to flow through the cap  21  into a receptacle (not shown). Upon removal of cap  21  from the receptacle, and hence removal of the pin (not shown) from passageway  37 , the magnetic attraction between the steel ball  29  and flat washer  37  causes the steel ball  29  to again bias against o-ring  33 , resealing the passageway  39 , as illustrated in FIG.  13 . 
     The cap of the present invention may be applied to existing inkjet ink receptacle by using an adapter, if necessary. FIGS. 15-18 illustrate a suitable adapter. Adapter  41  exhibits threads  43  to engage an inkjet ink receptacle (not shown) designed to receive a threaded inkjet ink bottle cap (not shown) at top  45 . Portion  45  of adapter  41  screws into an inkjet ink receptacle (not shown) using key receiver  47  and key  49 . FIG. 17 exhibits both top and longitudinal side views of key  49 . The non-threaded inkjet ink bottle cap seals with adapter  41  with an o-ring in upper portion  51 . Upper portion  51  of adapter  41  receives a non-threaded bottle cap (not shown). Upper portion  51  may be sealed without a bottle cap using plug  53 . 
     One of ordinary skill in the art, with the benefit of this disclosure, will recognize that many other embodiments of the invention are possible within the scope of the claims. Any two magnetically attracted contact points, which are displaced from each other upon insertion of a inkjet ink cap into a receptacle, and which displacement is reversed upon removal, may be suitable. A “receptacle” may be any receiver for inkjet ink for which the cap of the present invention is useful.