Information
-
Patent Grant
-
6334391
-
Patent Number
6,334,391
-
Date Filed
Monday, October 2, 200023 years ago
-
Date Issued
Tuesday, January 1, 200222 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Bullwinkel Partners, Ltd.
-
CPC
-
US Classifications
Field of Search
US
- 101 366
- 101 364
- 101 365
- 101 210
- 347 85
- 347 86
-
International Classifications
-
Abstract
An improved ink cartridge dispensing valve system for use with a printing press ink cartridge is provided. The valve system works on the same principle as a ball valve to automatically dispense ink when subjected to pressure. The valve system includes an attachment post and an attachable nozzle. The attachment post is an integral part of the dispensing end of the ink cartridge and is recessed so that the cartridge can be easily shipped without damaging the attachment post. The attachable nozzle fits over the attachment post and opens or closes depending on whether pressure is placed on it by the ink in the cartridge.
Description
BACKGROUND
1. Field of the Invention
This patent relates to liquid dispensing cartridges for automated dispensing systems. More specifically, this patent relates to a dispensing valve system attachable to an ink cartridge that automatically opens and closes in response to pressure from the ink.
2. Description of the Related Art
Lithography is a printmaking process dating back to the 1700s in which ink is applied to a plate having both image and non-image areas. The image areas are ink-receptive and water-repellent. The non-image areas are water-receptive and ink-repellent. In rotary type lithographic presses the ink plate is mounted on a cylinder that rotates during printing. In one typical configuration, the plate cylinder picks up the ink at the image areas and transfers the image to a blanket cylinder which then transfers the image to the paper.
In multi-color sheet-fed presses, up to ten inking stations can be placed in series. Each station has its own ink feeding system and handles a separate color. As the paper sheet moves from station to station, a new color is put down at each station.
Because lithographic ink is thixotropic, conventional lithographic ink feeding systems require a complex system of drums, vibrators and fountain rollers. In a typical lithographic ink feeding system, workers remove lithographic ink from a drum (or, in some cases, smaller tins) with specially made spatulas and spread the ink across a tray (the ink fountain). Fountain rollers roll against the ink fountain to pick up the ink and transfer it to the plate cylinder. The process is labor intensive and subject to error.
Storing lithographic ink in drums can result in wasted ink if the entire drum is not used because it is difficult to store and reuse ink in drums. The lithographic ink itself is prone to oxidation which can result in color variations from one press run to another, and even from sheet to sheet within a single run. In addition, upon exposure of the ink to the atmosphere, volatile organic compounds (VOCs) evaporate, which can cause ink spoilage.
Consequently, many modern printers, including sheet fed lithographic printers, use smaller cartridges to dispense ink. During printing the ink cartridge moves back and forth across the fountain, dispensing ink into the fountain or directly onto an ink form roller to provide an even, consistent layer of ink. In automated presses, the amount of ink in the fountain is continually monitored and replenished as needed.
Ink cartridges can be easily filled, transported, used and reused. The cartridge minimizes exposure of the ink to the atmosphere and also minimizes the amount of residual ink left in the cartridge after use. The cartridge typically comprises a hollow cylindrical body, a plunger at one end and a dispensing fitment at the opposite end. The cylindrical body is filled with ink. The plunger serves as a piston within the cylindrical body to extrude the contents of the dispenser when the plunger is forced toward the dispensing end by, for example, pneumatic pressure.
The dispensing fitment is mounted in sealing engagement within the dispensing end of the cylindrical body and has a valve and nozzle for controlling the flow of ink. In one ink cartridge described in U.S. application Ser. No. 09/470,747, now U.S. Pat. No. 6,192,797 owned by the assignee of the present application, the valve is recessed below the edge of the cartridge and the nozzle extension is detachable so that the valve and nozzle extension do not become damaged during shipment. When ready to use at the printing plant, the nozzle extension is attached to the recessed valve and extends beyond the end of the cylindrical body. The valve must be manually opened to allow ink to flow.
While this type of dispensing cartridge is suitable for its particular purpose, it requires that the valve be manually opened and closed. Thus there exists a need for an improved ink cartridge dispensing valve system that operates in response to pressure from the ink to open and close.
Therefore it is an object of the present invention to provide an ink cartridge dispensing valve system that opens and closes in response to pressure from the ink.
Another object of the present invention is to provide an ink cartridge dispensing valve system that can be attached to a recessed universal attachment post at the printing press.
A further object of the present invention is to provide an attachable dispensing valve that can be used in a sheet fed lithographic printing press with a hand gun or with an automated printing system.
Still another object of the present invention is to provide an ink cartridge dispensing valve system that minimizes exposure of the ink to the atmosphere.
Yet another object of the present invention is to provide an ink cartridge dispensing valve system having a recessed universal attachment post for easy packing, shipping and storing.
Further and additional objects will appear from the description, accompanying drawings, and appended claims.
SUMMARY OF THE INVENTION
The present invention is an improved ink cartridge of the type used to dispense ink in automatic lithographic presses. The ink cartridge comprises a hollow cylindrical body for holding a supply of extrudable ink and has a dispensing end and a plunger end. The plunger end is closed by a plunger adapted to serve as a piston within the cylindrical body to extrude the contents of the dispenser when the plunger is forced toward the dispensing end by pneumatic or mechanical pressure. The dispensing end is closed by a dispensing fitment affixed thereto by glue or other suitable means. The improvement comprises an attachment post mounted over a central aperture in the dispensing fitment, the attachment post having a sidewall and a top wall, the top wall having a plurality of openings therein; a nozzle mounted over the attachment post and defining a substantially cylindrical space; a plate mounted within the substantially cylindrical space, the plate having a central opening; and a spring mounted within the substantially cylindrical space on the side of the plate away from the attachment post top wall to bias the plate in sealing engagement with the attachment post top wall. When pressure is exerted on the plate by the ink, the spring compresses, allowing ink to be extruded through the nozzle.
THE DRAWINGS
FIG. 1
is an exploded perspective view of an ink cartridge dispensing system according to the present invention;
FIG. 2
is a cross-sectional view of the ink cartridge dispensing system of
FIG. 1
shown in the closed position;
FIG. 3
is a cross-sectional view of the ink cartridge dispensing system of
FIG. 1
shown in the open position; and
FIG. 4
is a top plan view of the attachment post of the ink cartridge dispensing system of FIG.
1
.
DETAILED DESCRIPTION OF THE INVENTION
Turning to the drawings, there is shown in
FIG. 1
an exploded view of an ink cartridge dispensing system
10
made according to the present invention for use with a sheet fed lithographic press. The ink cartridge dispensing system
10
comprises a nozzle
12
, a spring
14
, an annular plate
16
and an attachment post
18
. The attachment post
18
may be formed as an integral part of the dispensing fitment
20
.
The dispensing fitment
20
is mounted in sealing engagement with the top end of the cartridge body
22
. The dispensing fitment
20
may be glued to the cartridge body
22
or attached by any other suitable means. The top end of the cartridge body
22
terminates in a rim or edge
24
.
Preferably, the cartridge body
22
is made of convolutely wound paper lined internally with polymeric material, although any suitable materials may be used, including, depending on the application, metal or plastic. In the preferred embodiment the dispensing fitment
20
, attachment post
18
and nozzle
12
are made of plastic. In practice, the cartridge body
22
typically is about nine or thirteen inches long, but any suitable length may be used depending on need.
In automated lithographic printing presses, the ink cartridge is mounted in an inverted position within a cartridge carriage (not shown). During operation, the carriage moves laterally along the length of a fountain roller while an ink level sensor constantly monitors the amount of ink in the fountain roller to determine the exact locations where ink is needed. When a low level of ink is detected by the sensor, the controller activates an air supply which forces air against a pneumatically controlled plunger slidingly engaged within the cartridge, which then forces ink onto the fountain roller. The ink cartridge dispensing system
10
of the present invention was specifically designed to work with automated ink dispensing systems of the type just described.
The dispensing fitment
20
is generally cup-shaped and comprises a substantially circular disk
26
and an annular sidewall
28
formed around the periphery of the disk
26
and extending upwardly therefrom (upward being defined as the direction away from the bottom or plunger end). An aperture is located at the center of the circular disk
26
through which ink may flow. A closure flange
30
extends radially outwardly from the top end of the annular sidewall
28
. When the dispensing fitment
20
is fully inserted into the cylindrical body
22
, the closure flange
30
abuts the rim
24
of the cylindrical body
22
to prevent further insertion of the dispensing fitment
20
.
The attachment post
18
is mounted on the circular disk
26
over the central aperture. As shown in
FIGS. 2 and 3
, the attachment post
18
has a substantially cylindrical sidewall
32
extending upwardly from the perimeter of the circular aperture and a convex top wall
34
. As best seen in when viewed from above (FIG.
4
), the convex top wall
34
comprises a top plug
36
centrally disposed over the circular disk aperture and connected to the sidewall
32
by four arcuate bridges
38
. The top plug
36
, bridges
38
and sidewall
32
define four openings
40
through which the ink can flow when the dispensing system
10
is in the open position.
Referring to
FIGS. 2 and 3
, the nozzle
12
fits over the attachment post
18
in fixed relationship thereto. In the illustrated embodiment, the nozzle
12
is screwed upon the externally threaded sidewall
32
, although any suitable means of attachment will suffice.
The spring
14
and the annular plate
16
are disposed within the nozzle
12
in a cylindrical space
42
above the attachment post
18
. The plate
16
has a centrally disposed hole
44
through which ink may flow. The plate
16
is made of a material that is impervious to ink, such as polyethylene. In the preferred embodiment shown in
FIG. 3
, the hole
44
has a cylindrical portion
46
and a concave portion
48
. The upper wall
50
of the concave portion
48
mates with the convex top wall
34
of the attachment post
18
to form a seal when the dispensing system is in the CLOSED position (FIG.
2
).
The spring
14
also has a hole in the middle and/or is pervious to ink. The spring
14
is compressible and resilient, and serves to bias the plate
16
against the attachment post
18
to seal off the flow of ink.
The CLOSED position of the dispensing system
10
is shown in FIG.
2
. The spring
14
is expanded so that the spring
14
and plate
16
fill the cylindrical space
42
within the nozzle
12
. The spring
14
biases the plate
16
against the attachment post
18
. In this position, the plate
16
is seated against the plug
36
to seal off the channel
44
through the plate
16
. Ink cannot flow through the nozzle.
The OPEN position of the dispensing system is shown in FIG.
3
. When pressure from the ink impinges on the dispensing system
10
, the spring
14
compresses and the plate
16
disengages the attachment post top wall
34
. Ink then flows through the openings
40
in the attachment post top wall
34
and through the nozzle
12
.
Thus the present invention provides a dispensing system for an ink cartridge having a spring loaded plate
18
. The cartridge automatically dispenses ink when the plunger end is depressed, forcing ink through the nozzle. The present invention is particularly suitable as an ink dispenser for use with a sheet fed lithographic press having an automatic ink level sensor.
Other modifications and alternative embodiments of the invention are contemplated which do not depart from the spirit and scope of the invention as defined by the foregoing teachings and appended claims. For example, it is contemplated that attachment post top wall may be flat or some other suitable shape. It is intended that the claims cover all such modifications that fall within their scope.
Claims
- 1. In an ink cartridge comprising a hollow cylindrical body for holding a supply of extrudable ink, the cylindrical body having a dispensing end and a plunger end, the plunger end being closed by a plunger adapted to serve as a piston within the cylindrical body to extrude the contents of the dispenser when the plunger is forced toward the dispensing end, the dispensing end being closed by a dispensing fitment affixed thereto, the improvement comprising:an attachment post mounted over a central aperture in the dispensing fitment, said attachment post having a sidewall and a top wall, said top wall having a plurality of openings therein; a nozzle mounted over the attachment post, said nozzle defining a substantially cylindrical space; a plate mounted within the substantially cylindrical space, said plate having a central opening; and a spring mounted within the substantially cylindrical space on the side of the plate away from the attachment post top wall, said spring biasing the plate in sealing engagement with the attachment post top wall; wherein pressure exerted on the plate by the ink causes ink to be extruded through the nozzle.
- 2. The dispensing system of claim 1 wherein the top wall is convex and the plate has a concave surface that engages the top wall in sealing relationship when the plate is biased against the top wall.
- 3. The dispensing system of claim 1 wherein the spring is pervious to ink.
- 4. The dispensing system of claim 1 wherein the spring has a central opening.
- 5. The dispensing system of claim 1 wherein the top wall of the attachment post comprises a plug centrally disposed over the aperture in the dispensing fitment and connected to the sidewall by arcuate bridges.
US Referenced Citations (11)
Foreign Referenced Citations (3)
Number |
Date |
Country |
0 690 815 |
Dec 1996 |
DE |
197 05 201 |
Apr 1998 |
DE |
10-217430 |
Aug 1998 |
JP |