Dripless seal for a liquid toner cartridge

Abstract: A container (10) for holding liquid in its interior comprises an aperture (24) which provides access to the interior of the container (10). A valve (20) has an open position and a closed position, is mounted in the aperture (24) and mates with an actuator (40) when the container (10) is inserted into a print mechanism. The actuator (40) causes the valve (20) to transition from the closed position to an open position and vice-versa. A seal member (30) is rotatably mounted in the aperture (24) and includes a pathway (52) for receiving the actuator (40). The pathway (52) is normally positioned non-aligned with the aperture (24) so as to render the valve (20) non-accessable from outside the container (10). A control mechanism (32) is coupled to the seal member (30) and rotatably moves the seal member (30) to reposition the pathway (52) into a alignment with the aperture (24) so as to be in position to receive the actuating means. The control mechanism (32) is actuated when the container (10) is inserted into the print mechanism.

Description: FIELD OF THE INVENTION This invention relates to electrophotographic(EP) printing and, more particularly, to a user-replaceable liquid toner cartridge for an EP printer. BACKGROUND OF THE INVENTION To maintain costs as low as possible, EP printers are now designed to allow as much user maintenance as possible. To this end, dry toner EP printers enable a user to replace an exhausted toner cartridge with a new toner cartridge which also contains an entirely new organic photoconductor-coated drum and related actuating mechanisms. EP printers which employ liquid toners are provided with refillable toner reservoirs, thus requiring the user to replenish the in-printer reservoir from a liquid toner supply. The user is thus exposed to possible spillage, vapors, and with color printers, the possibility that a wrong color toner will be loaded into a reservoir. In the earlier but non-prepublished US-A-5,396,316 "User-Replaceable Liquid Toner Cartridge With Integral Pump And Valve Mechanisms", a replaceable toner cartridge is described which includes an integral pump connected to a toner supply reservoir and a mechanical coupling that automatically receives a pump actuator when the liquid toner cartridge is inserted into an EP printer. The disclosed liquid toner cartridge structure enables replacement of the pump each time the liquid toner cartridge is replaced, thereby replacing a failure-prone part and providing for more reliable operation of the EP printer. A further valve is connected to an output from the pump and communicates with an external wall of the toner cartridge where it connects to a fluid fitting in the receptacle in the EP printer. The fluid fitting automatically operates the valve in the cartridge and enables liquid toner flow from the cartridge's reservoir into the receptacle's fluid fitting. Even though the fitting is a "dripless" coupling, its external surface is liquid-toner coated when the cartridge is removed from the EP printer. Such toner can stain a user's hands and/or clothing and requires a level of care in handling which many customers are not willing to exert. The prior art has attempted to solve the toner contamination problem by incorporating a door/shutter arrangement into a coupling surface of a replaceable toner cartridge. Such an arrangement enables a user with finger pressure, to open the door-shutter and to access the toner-stained portion of the cartridge's fluid coupling. US-A-4,518,1240 relates to a photographic print and developing tray which is to removably connect to the body of the base of a photographic enlarger. The tray is to accommodate photographic print developing liquid, and the liquid is to be supplied to the tray through a dispenser. The dispenser includes a spout to tightly engage with the tray. The dispenser also includes a manually operable valve which is movable from a closed position to an open position to permit moving of liquid between the tray and the dispenser. It is the object of the present invention to provide an improved, user-replaceable liquid toner cartridge with a mechanism which prevents liquid toner from being present on an external surface of the cartridge when it is being handled by a user, and includes a means for sealing a toner access valve, the means for sealing being inexpensive and positioned in a wall of the cartridge. This object is achieved by a container for holding a liquid toner in its interior according to claim 1. DESCRIPTION OF THE DRAWINGS Fig. 1 is a perspective view of a liquid toner container which incorporates the invention hereof. Fig. 2 is a schematic sectional view of the liquid toner container shown in Fig. 1, as it is inserted into an EP printer. Fig. 3 is a side sectional view showing a seal member in a closed position that is used in the liquid toner cartridge. Fig. 4 is a side sectional view showing the seal member of Fig. 3 in an open position. Fig. 5 is a front view of the seal member, removed from the front wall of the toner cartridge of Fig. 2. Fig. 6 shows an alternative mechanism for actuating the seal member. Fig. 7 illustrates a liquid coupling which enables liquid toner to flow from within the liquid toner cartridge and into an EP printer. DETAILED DESCRIPTION OF THE INVENTION In Fig. 1, liquid toner cartridge 10 comprises an outer casing 12 into which is molded an alignment extension 14 and an end plate 16. Outer casing 12 is preferably comprised of an appropriate rigid plastic material which provides structural rigidity to liquid toner cartridge 10 and enables normal handling thereof. As shown in Fig. 2, the interior volume of liquid toner cartridge 10 includes a flexible plastic bag 18 which holds a supply of liquid toner. Bag 18 is provided with a valve outlet 20 (shown schematically) which is attached to a front wall 22 of liquid toner cartridge 10. Front wall 22 is provided with three apertures, i.e. 24, 26 and 28. Fluid coupling 20 is mounted so as to communicate with aperture 24 and is positioned in the internal volume of toner cartridge 10. A rotatable seal member 30 is positioned intermediate fluid coupling 20 and the outer surface of wall 22. Seal member 30 is provided with an actuating arm 32 which extends generally downwardly adjacent aperture 26. (Details of seal member 30, aperture 24 and fluid coupling 20 will be described below with respect to figs. 3-7.) Toner cartridge 10 is constructed so as to be insertable into a toner receptacle within an EP printer. Only sidewalls 34, 36 and endwall 38 of the EP toner receptacle are illustrated in Fig. 2. A fluid coupling 40 extends from rear wall 38 and is adapted to engage fluid coupling 20 (through seal 30) when toner cartridge 10 is inserted into the toner receptacle. An actuating arm 42 is positioned immediately beneath fluid coupling 40 and mates with aperture 26 to engage actuating member 32 when toner cartridge 10 is emplaced within the toner receptacle. This action causes seal member 30 to open a pathway so that fluid coupling 40 may mate with fluid coupling 20. A small diameter pipe 44 extends from wall 38 and is connected to a pressurization supply within the EP printer. Pipe 44 mates with aperture 28 and enables pressurization of bag 18 (and the toner contained therein) within toner cartridge 10. Turning to Figs. 3, 4 and 5, further details of seal member 30 will be described. In a preferred embodiment, seal member 30 comprises an inner foam core 50 which is toner-absorbent. A pathway 52 is formed within the interior of foam core 50 and provides an accessway for fluid coupling 40 (see Fig. 2) to mate with fluid coupling 20 (Fig. 3). An outer hard plastic shell 54 encases foam core 50, except for a portion 56 which abuts a face of fluid coupling 20. In Fig. 3, seal member 30 is shown in a closed position, with pathway 52 vertically oriented and inaccessible through aperture 24. In this configuration, open portion 56 of foam core 50 abuts the face of fluid coupling 20 and is positioned to absorb excess toner which may be present thereon. Fig. 5 illustrates a front view of seal member 30 as seen along line 5-5 in Fig. 4. Seal member 30 is rotatably mounted on a pair of axles 58, 60. Actuating arm 32 extends downwardly from axle 58 and is rigidly coupled thereto. Axles 58 and 60 mount in apertures (not shown) within wall 22 of liquid toner container 10. Axle 60 includes a spring 62 which spring biases actuating arm 32 towards aperture 26. Spring 62 bias acts to maintain pathway 52 in its "closed" position until toner cartridge 10 is inserted into the toner receptacle. At such time, arm 42 enters aperture 26 and causes arm 32 to rotate in a counter-clockwise direction. This action causes seal member 30 to rotate in a counter-clockwise direction until pathway 52 is aligned with the inner walls of aperture 24.(See fig. 4). Once the orientation of seal member 30 has been changed to that shown in Fig. 4, further insertion of toner receptacle 10 causes fluid coupling 40 to enter pathway 52 and to engage fluid coupling 20. This action enables a coupling of the toner fluid within bag 18 into the EP printer. Seal member 30 is preferably spherically shaped (as shown in Fig. 5) so as to snugly fit within a circular aperture 24. While not as preferred, seal member 30 may also be cylindrical in shape, with aperture 24 having a rectangularly shaped opening. Upon removal of liquid toner cartridge 10 from the toner receptacle, coupling 40 first comes out of engagement with fluid coupling 20. As soon as the end of fluid coupling 40 clears seal member 30, the end of arm 42 withdraws through aperture 26, thereby enabling seal member 30 to rotate in a clockwise direction until actuating arm 32 makes contact with the inner surface of wall 26. At this time, the configuration of seal member 30 returns to that shown in Fig. 3. Any excess fluid that remains on the external face of fluid coupling 20 is absorbed by foam 50. Shell 54 prevents any toner absorbed by foam 50 from being available to touch a user's clothing or hands. Fig. 6 shows an alternative arrangement for actuating seal member 30. In this case, a gear 70 is mounted on axle 58 and is rotated by a mating linear gear 72 when toner cartridge 10 is inserted into the toner receptacle. Linear gear 72 is designed so as to rotate seal member 30 by 90° when toner cartridge 10 is inserted into the toner receptacle. Fig. 7 shows a commercially-available fluid coupling that is usable with this invention. Fluid coupling 20 is female and includes a plunger within that is spring biased against casing 82. Male portion 84 is spring biased within coupling 40 and, when engaged with plunger 80, enables fluid flow from coupling 20 into coupling 40 and out through aperture 86. It should be understood that the foregoing description is only illustrative of the invention. Various alternatives and modifications can be devised by those skilled in the art without departing from the invention as defined in the claims.

Claims: A container (10) for holding a liquid toner in its interior and comprising: an aperture (24) through an outer wall (22) of said container (10) and providing access to said interior; a valve (20) connected to said aperture (24), for mating with an actuating means (40) which causes said valve (20) to transition from a closed position to an open position and vice-versa; a seal member (30) rotatably mounted in said aperture (24) between said outer wall (22) and said valve (20), said seal member (30) having a pathway (52) for receiving said actuating means (40), said pathway (52) normally positioned non-aligned with said aperture (24) so as to render said valve (20) inaccessible through said outer wall (22); and control means (32) coupled to said seal member (30) for rotatably moving said seal member (30) to reposition said pathway (52) into alignment with said aperture (24) so as to be positioned to receive said actuating means (40), said control means (32) positioned to be actuated by insertion or extraction of an extended member (42) from a position external to said container (10). The container (10) as recited in claim 1 wherein said seal member (30) exhibits a circular cross section and is rotatable in a plane of said circular cross section. The container (10) as recited in claim 1 wherein said seal member (30) is comprised of a material that is absorbent of said liquid toner. The container (10) as recited in claim 2 wherein said seal member (30) is spherical in shape and is mounted for rotation in said wall by a pair of axles (58, 60). The container (10) as recited in claim 1 wherein said control means (32) is an arm that extends from an axle (58) that mounts said seal member (30) and is actuated by a rod (42) that is inserted from exterior to said container (10). The container (10) as recited in claim 5 wherein said container (10) is constructed to be insertable into a printer mechanism, said printer mechanism provided with both a rod (42) for operating said seal member (30) and an actuator (40) for operating said valve member (20). The container (10) as recited in claim 6 wherein said seal member (30) includes a core (50) that is liquid toner absorbent and a circumference of said seal member (30) that is exposed to an area exterior to said container (10) when said pathway (52) is nonaligned with said aperture (24), is encompassed by a plastic cover (54) to render said liquid toner absorbent core (50) inaccessible to a user.

Inventors: GIRARD JAMES J, SMITH DAVID L, GIRARD, JAMES J., SMITH, DAVID L.
Applicants: HEWLETT PACKARD CO, HEWLETT-PACKARD COMPANY
Application year: 1995
Main classification: G03G15
IPC codes: G03G15, G03G21