Print head shutter

Information

  • Patent Grant
  • 6726306
  • Patent Number
    6,726,306
  • Date Filed
    Wednesday, July 10, 2002
    23 years ago
  • Date Issued
    Tuesday, April 27, 2004
    21 years ago
Abstract
A shutter for a print head of a print cartridge is provided. The shutter includes a cover movably attachable to the print cartridge. The cover is movable between a closed position to cover the print head and an open position to expose the print head. An arm is pivotally attachable to the print cartridge and is movably attached to the cover. A biasing device for biasing the cover in the closed position is attached to the arm and is attachable to the print cartridge.
Description




FIELD OF THE INVENTION




The present invention relates generally to shutters for print heads.




BACKGROUND




Many imaging devices used to print labels on objects, such as cartons, boxes, or the like employ a stationary inkjet print cartridge having a print head. Printing is accomplished by moving the object past the print head so that the print head deposits an image on the object by spraying ink through a number of nozzles in the print head onto the object. However, when the print head is not being used, many inks dry out, clogging the nozzles. For imaging devices, such as desktop printers, having movable print heads that move over a stationary printable medium during printing, the print cartridge and thus the print head is moved to a location where the print head is covered to prevent the ink from drying out and clogging the nozzles when the imaging device is not in use. However, by design stationary print heads cannot be moved to a location for covering the print head.




For the reasons stated above, and for other reasons stated below that will become apparent to those skilled in the art upon reading and understanding the present specification, there is a need in the art for preventing inks from drying out and clogging the nozzles of the print heads of stationary print cartridges.




SUMMARY




One embodiment of the present invention provides a shutter for a print head of a print cartridge. The shutter includes a cover movably attachable to the print cartridge. The cover is movable between a closed position to cover the print head and an open position to expose the print head. An arm is pivotally attachable to the print cartridge and is movably attached to the cover. A biasing device for biasing the cover in the closed position is attached to the arm and is attachable to the print cartridge.




In another embodiment, a print cartridge is provided. The print cartridge includes a body and a print head. A cover is movably attached to the body. The cover is movable within a plane substantially parallel to the print head between a closed position to cover the print head and an open position to expose the print head. An arm is pivotally attached to the body and is movably attached to the cover for moving the cover between the closed and open positions. A biasing device is attached to the arm and the body for biasing the cover in the closed position.




Further embodiments of the invention include methods and apparatus of varying scope.











DESCRIPTION OF THE DRAWINGS





FIG. 1

is a plan view of a print cartridge according to an embodiment of the present invention.





FIG. 2

is a plan view of the print cartridge of

FIG. 1

illustrating exposure of a print head of the print cartridge according to another embodiment of the present invention.





FIG. 3

is an enlarged view of region


300


of FIG.


1


.





FIG. 4

illustrates slidable attachment of a cover of the print cartridge of

FIG. 1

according to another embodiment of the present invention.











DETAILED DESCRIPTION




In the following detailed description of the present embodiments, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments in which the invention may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that process, electrical or mechanical changes may be made without departing from the scope of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the present invention is defined only by the appended claims and equivalents thereof.





FIG. 1

is a plan view of a print cartridge


100


according to an embodiment of the present invention. Print cartridge


100


includes a cartridge body


102


and a print head


104


or other marking device for depositing an image on a moving object, e.g. object


110


. In one embodiment, print cartridge


100


is an inkjet cartridge and print head


104


includes a number of nozzles


105


. Print cartridge


100


includes a shutter


106


or the like, for covering and uncovering print head


104


. Shutter


106


is closed to cover print head


104


when print head


104


is not in use. This prevents ink of cartridge


100


from drying out and potentially clogging nozzles


105


of print head


104


. A conveyer


108


, such as a moving belt or the like, conveys object


110


, e.g., a box, carton, or the like past print cartridge


100


. Object


110


engages shutter


106


and moves shutter


106


from the closed position to an open position, as shown in

FIG. 2

, where print head


104


is exposed for printing on object


110


as object


110


movies past print cartridge


100


. After object


110


moves out of engagement with shutter


106


, shutter


106


automatically returns to the closed position.




More specifically, shutter


106


includes an arm


112


movably attached to a cover


116


of shutter


106


for moving cover


116


between the closed position shown in FIG.


1


and the open position shown in FIG.


2


. In one embodiment, arm


112


is pivotally attached to cartridge body


102


by a pivot


114


, such as a pin. Cover


116


is movable between the closed position to cover print head


104


and the open position to expose print head


104


. In another embodiment, cover


116


is movable within a plane substantially parallel to a face plane


117


(shown in

FIG. 2

) of print head


104


. Shutter


106


also includes a biasing device


118


connected between arm


112


and cartridge body


102


for automatically returning cover


116


to the closed position after object


110


moves out of engagement with arm


112


. In one embodiment, biasing device is a spring, an elastic strip, or the like. Biasing device


118


biases cover


116


in a closed position, as shown in

FIG. 1

, so that cover


116


covers print head


104


when print head


104


is not in use to prevent the ink from drying out and potentially clogging nozzles


105


of print head


104


.





FIG. 3

is an enlarged view of region


300


of

FIG. 1

illustrating attachment of arm


112


to cover


116


. In one embodiment, a pin


120


protrudes from an edge


122


of cover


116


and extends into a slot


124


of arm


112


. Cover


116


is movably attached to a protrusion


126


of cartridge body


102


, e.g., using rollers, slides or the like. Biasing device


118


exerts a force on arm


112


so that arm


112


bears against pin


120


of cover


116


to bias cover


116


in the closed position, as shown in

FIGS. 1 and 3

.




In one embodiment, a seal


125


, e.g., an elastomer or the like, is disposed on an edge


127


of cover


116


substantially perpendicular to edge


122


, as shown in FIG.


3


. When cover


116


is in the closed position seal


125


abuts protrusion


129


of cartridge


100


, reducing exposure of print head


104


to the environment outside cartridge


100


, thus helping to prevent the ink of cartridge


100


from drying out and potentially clogging nozzles


105


of print head


104


.





FIG. 4

illustrates slidable attachment of cover


116


to protrusion


126


according to another embodiment of the present invention. Rails


400


of cover


116


slide within grooves


410


disposed within protrusion


126


. This maintains cover


116


substantially parallel to a face plane


117


of print head


104


as cover


116


slides between the closed and open positions. In one embodiment, rails


400


are integral with cover


116


.




Object


110


engages arm


112


and pivots arm


112


about pivot


114


against the biasing force exerted on arm


112


by biasing device


118


. As arm


112


pivots, arm


112


exerts a force on cover


116


via pin


120


. This moves cover


116


in the direction of motion of object


110


to the open position, as shown in

FIG. 2

, thereby exposing print head


104


. As arm


112


opens cover


116


, pin


120


travels within slot


124


of arm


112


so that cover


116


moves substantially parallel to print head


104


.




In one embodiment, pin


120


is located adjacent an end


134


of slot


124


when cover


116


is closed, as shown in FIG.


3


. In another embodiment, when cover


116


is open, pin


120


is located adjacent an end


136


of slot


124


that is opposite end


132


, as shown in FIG.


3


. In some embodiments, an extension


140


extends angularly from an end


142


of arm


112


to form an angle


144


with respect to arm


112


, as shown in FIG.


1


. In one embodiment, angle


144


is such that extension


140


is substantially parallel with face plane


117


of print head


104


and abuts cover


116


when cover


116


is open, as shown in FIG.


2


.




Object


110


moves over extension


140


as it moves past print cartridge


100


. As object moves past print head


104


, ink is sprayed through nozzles


105


of print head


104


onto object


110


to deposit an image on object


110


. In one embodiment, a gap


146


separates print head


104


from object


110


during printing, as shown in

FIG. 2

, and the ink is sprayed across gap


146


.




After object


110


moves past and out of engagement with extension


140


, biasing device


118


returns arm


112


to the position shown in

FIG. 1

, thereby closing cover


116


. Specifically, biasing device


118


pivots arm


112


about pivot


114


, and arm


112


exerts a force on cover


116


via pin


120


, causing cover


116


to move counter to the direction of motion of object


110


into the closed position. As arm


112


closes cover


116


, pin


120


travels within slot


124


in a direction from end


136


to end


134


so that cover


116


moves substantially parallel to print head


104


.




CONCLUSION




Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that any arrangement that is calculated to achieve the same purpose may be substituted for the specific embodiments shown. Many adaptations of the invention will be apparent to those of ordinary skill in the art. Accordingly, this application is intended to cover any adaptations or variations of the invention. It is manifestly intended that this invention be limited only by the following claims and equivalents thereof.



Claims
  • 1. A shutter for a print head of a print cartridge, comprising:a cover movably attachable to the print cartridge, the cover movable between a closed position to cover the print head and an open position to expose the print head; an arm pivotally attachable to the print cartridge and movably attached directly to the cover; and a biasing device for biasing the cover in the closed position, the biasing device attached to the arm and attachable to the print cartridge.
  • 2. The shutter of claim 1, wherein a pin of the cover extends into a slot of the arm to movably attach the arm to the cover.
  • 3. The shutter of claim 1, wherein the biasing device is a spring.
  • 4. The shutter of claim 1, wherein the cover is movable within a plane substantially parallel to a face plane of the print head.
  • 5. The shutter of claim 1, wherein the arm comprises an extension extending at an angle relative to the arm such that when the cover is in the open position the extension is substantially parallel with a face plane of the print head.
  • 6. The shutter of claim 1, wherein the cover comprises a seal.
  • 7. A print cartridge comprising:a body; a print head; a cover movably attached to the body, the cover movable within a plane substantially parallel to a face plane of the print head between a closed position to cover the print head and an open position to expose the print head; an arm pivotally attached to the body and movably attached to the cover for moving the cover between the closed and open positions; and a biasing device attached to the arm and the body for biasing the cover in the closed position; wherein the arm is pivotable from a first position corresponding to the closed position of the cover to a second position corresponding to the open position of the cover by an object to be printed upon by the print head as the object moves past the print head during printing.
  • 8. The print cartridge of claim 7, wherein the print head comprises a plurality of nozzles.
  • 9. The shutter of claim 7, wherein the biasing device is a spring.
  • 10. The shutter of claim 7, wherein the cover is slidably attached to the body.
  • 11. A print cartridge comprising:a body; a print head; a cover movably attached to the body, the cover movable within a plane substantially parallel to a face plane of the print head between a closed position to cover the print head and an open position to expose the print head; an arm pivotally attached to the body and movably attached to the cover by a pin extending from the cover into a slot of the arm, the arm pivotable between a first position corresponding to the cover being in the closed position and a second position corresponding to the cover being in the open position, the arm exerting a force on the pin as the arm pivots between the first and second positions to move the cover between the closed and open positions, the pin traveling within the slot as the arm pivots so that the cover moves within the plane substantially parallel to the face plane of the print head; and a biasing device attached to the arm and the body for biasing the cover in the closed position; wherein the arm is pivoted pivotable from the first position to the second position by an object to be printed upon by the print head as the object moves past the print head during printing.
  • 12. A method for printing comprising:moving an object to be printed upon relative to a stationary print head and into contact with a shutter; moving the shutter from a closed position, where the shutter covers the print head, to an open position, where the print head is exposed, by moving the object against the shutter; depositing an image on the object using the print head as the object moves relative to the print head; and automatically returning the shutter to the closed position after the object moves out of contact with the shutter.
  • 13. The method of claim 12, wherein moving the shutter comprises the object moving an arm of the shutter so that the arm moves a cover of the shutter from the closed position to the open position.
  • 14. The method of claim 13, wherein automatically returning the shutter to the closed position comprises using a biasing device for biasing the cover in the closed position to move the arm of the shutter so as to move the cover from the open to the closed position.
  • 15. The method of claim 12, wherein depositing an image on the object using the print head comprises the print head spraying ink onto the object across a gap separating the print head from the object.
  • 16. A print cartridge, comprising:a means for depositing an image on a moving object; and a means for covering and uncovering the image depositing means, wherein the covering and uncovering means uncovers the image depositing means as the object contacts and moves against the covering and uncovering means and automatically covers the image depositing means after the object moves out of contact with the covering and uncovering means.
  • 17. The print cartridge of claim 16, wherein the image depositing means is a print head.
  • 18. The print cartridge of claim 16, wherein the image depositing means comprises nozzles for spraying ink onto the object.
  • 19. The print cartridge of claim 16, wherein the covering and uncovering means comprises a shutter.
  • 20. The print cartridge of claim 16, wherein the covering and uncovering means comprises a cover for covering the image depositing means movably attached to the print cartridge and a means for moving the cover between positions where the cover covers and uncovers the image depositing means.
  • 21. The print cartridge of claim 20, wherein the cover moving means is an arm movably attached to the cover.
  • 22. The print cartridge of claim 20, wherein the covering and uncovering means comprises a means for automatically returning the cover from the position uncovering the image depositing means to the position covering the image depositing means by moving the cover moving means.
  • 23. The print cartridge of claim 22, wherein the automatic cover returning means is a biasing device for biasing the cover in the position covering the image depositing means.
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