Information
-
Patent Grant
-
6739710
-
Patent Number
6,739,710
-
Date Filed
Tuesday, December 24, 200221 years ago
-
Date Issued
Tuesday, May 25, 200420 years ago
-
Inventors
-
Original Assignees
-
Examiners
Agents
- Birch, Stewart, Kolasch & Birch, LLP
-
CPC
-
US Classifications
Field of Search
US
- 347 84
- 347 85
- 347 86
- 347 87
-
International Classifications
-
Abstract
This specification discloses a negative pressure-regulating airbag for an embedding-type ink cartridge and its assembly method. In addition to a bag with a variable volume, the negative pressure-regulating airbag has a buckle ring, a plate, and a elastic element. The buckle ring is closely connected to the bag. A vent hole is formed in the middle of the buckle ring, allowing air to enter or escape the airbag when the ambient pressure changes. The buckle ring has a protruding part on the surface of the bag so as to be embedded into a preserved hole on an ink cartridge by pressing during the assembly. This forms a quick and tight connection between the airbag and the ink cartridge. One end of the elastic element is connected to the ink cartridge and the other end to the plate so that the plate imposes a force to depress the airbag. This keeps a negative pressure inside the cartridge to prevent ink leakage from the cartridge during transportation or use.
Description
BACKGROUND OF THE INVENTION
1. Field of Invention
The invention relates to a pressure-regulating airbag for ink cartridges and, in particular, to an airbag that is embedded in an ink cartridge and the assembly method therefor.
2. Related Art
The ink cartridge is an essential element for any inkjet pen. If there is no pressure-regulating device inside the cartridge, ink may leak out when the ambient pressure becomes low, for example, during transportation by air. This will result in unacceptable inkjet cartridge products. Moreover, unexpected temperature rise in the storage place is likely to increase the pressure inside the cartridge that may cause ink leakage too.
The importance of the pressure-regulating design of the ink cartridge is further seen in the continuous operation of an inkjet mechanism. As the ink is consumed, the ink volume becomes smaller, resulting in an increasing negative pressure. If the pressure is not appropriately tuned, the negative pressure may diminish or cancel with the ink ejection force from the inkjet chip, losing the ink droplet ejection precision. Eventually, the inkjet printer performance will be seriously affected. What is worse is that the internal negative pressure disallows the inkjet chip to eject ink before the ink is depleted.
There are already many patents or products with an ink cartridge negative pressure reduction mechanism. For example, a classic example is the U.S. Pat. No. 5,409,134. It proposed a design that used a thin plate spring to support the airbag. After then, various ideas were disclosed in accord with the pros and cons of the patent. However, most of the known designs put emphasis upon the variations and modifications in the pressure-regulating mechanisms, but the problem of how to increase the efficiency of assembling the inkjet cartridge and pressure-regulating element is never addressed.
SUMMARY OF THE INVENTION
An objective of the invention is to provide a negative pressure-regulating airbag that is embedded into an ink cartridge by pressing and the method for assembling it, so that the assembly of the airbag and the ink cartridge can be quickly and conveniently achieved.
In addition to a bag with a variable volume, the disclosed negative pressure-regulating airbag has a buckle ring, a plate, and an elastic element. The buckle ring is closely connected to the bag. A vent hole is formed in the middle of the buckle ring, allowing air to enter or escape the airbag when the ambient pressure changes. The buckle ring has a protruding part on the surface of the bag so as to be embedded into a preserved little hole on an ink cartridge by pressing during the assembly. This forms a quick and tight connection between the airbag and the ink cartridge. One end of the elastic element is connected to the ink cartridge and the other end to the plate so that the plate imposes a force to depress the airbag. This keeps the negative pressure inside the cartridge within a desired range to prevent ink leakage from the cartridge due to the ambient pressure change during transportation or use.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will become more fully understood from the detailed description given hereinbelow illustration only, and thus are not limitative of the present invention, and wherein:
FIG. 1
is a schematic view of the disclosed airbag according to a first embodiment of the invention;
FIG. 2
is a schematic view showing the relation among the spring, plate and ink cartridge in
FIG. 1
;
FIG. 3
is a schematic view of pressure adjustment in
FIG. 1
;
FIG. 4
is a schematic view of replenishing air in
FIG. 1
;
FIG. 5
is another embodiment of the invention; and
FIG. 6
is a diagram of the force to the location for compression springs and torsion springs.
DETAILED DESCRIPTION OF THE INVENTION
First Embodiment
As shown in
FIG. 1
, the disclosed negative pressure-regulating airbag
20
has a bag with a variable volume, a buckle ring
30
, a plate
50
, and an elastic element
40
(see FIG.
2
). The buckle ring
30
is tightly sealed onto the bag. A vent hole
31
is formed in the middle of the buckle ring
30
for air to enter or escape the airbag
20
when the ambient pressure changes. The buckle ring
30
has a protruding part
32
so as to be embedded into a preserved little hole
11
on an ink cartridge
10
by pressing during assembly. Therefore, the connection between the bag and the ink cartridge
10
is quick and air-proof.
With reference to
FIG. 2
, the elastic element
40
comprises two torsion spring
401
,
402
. One end of each torsion spring
401
,
402
is connected with each other and to the plate
50
. The other end of each torsion spring
401
,
402
is connected to the ink cartridge. The elastic element
40
imposes an evenly distributed force on the airbag
20
via the plate
50
. The pressure inside the ink cartridge
10
is thus kept within a desired range because the airbag
20
tends to shrink. This can avoid ink leakage during transportation or storage or the ambient air pressure suddenly changes during use.
With reference to
FIG. 6
, the force of the compression spring is increasing with the change of the air-bag location. This will increase the balancing pressure of the air-bag to let the controlling difficult and unstable. But the force of the torsion spring is near equal between operation ranges, though the change of the air-bag location. So it improves the stability of the pressure controlling.
Other Variations of the Embodiment
Aside from the above-mentioned embodiment, a person skilled in the part can further make various changes or modifications. For example, an element such as a wavy plate (not shown) can be disposed at the bending part of the air bag
20
to avoid opposite sides of the bag from sticking together. This can ensure that the air flows through the bending part without resistance.
Moreover, as shown in
FIG. 5
, the airbag
20
is changed from the folding type in
FIGS. 1 through 4
to a non-folding one
60
. This also achieves the objective of the invention.
Although the buckle ring
30
is embedded into a preserved little hole
11
on the ink cartridge
10
through its protruding part
32
, it is more desirable to form a one-way tilted texture, anti-skidding teeth, or equivalent means on the surface of the protruding part
32
so that it is completely fixed once being inserted into the little hole
11
. Based upon the same idea, a back hook or a stopper can be formed at the end of the protruding part
32
. Examples are an O-ring or another buckle ring that holds the protruding part
32
.
The above-mentioned variations of the disclosed embodiment are for illustrative purposes, and should not be construed as limitations of the scope of the invention. Any person skilled in the art can make other equivalent changes to the quality, appearance, and according to the costs.
Embodiment of the Assembly Procedure
The assembly method for the negative pressure adjusting airbag
20
,
60
is implemented through the following steps:
1. Connect the bag of the negative pressure adjusting airbag
20
,
60
with the buckle ring
30
. With reference to
FIG. 1
, the buckle ring
30
can be made of the same material as the bag surface (e.g. polyethylene) or some other material that can be easily assembled and produced by ejection. Afterwards, the buckle ring
30
is fixed onto the bag by surface mounting, thermal bonding, or bonding through vibration welding means (e.g. ultrasonic or high-frequency waves).
2. Connect the elastic element
40
with the plate
50
. With reference to
FIG. 2
, the plate
50
and the one end of the elastic element
40
can be connected by plugging, thermal welding or other equivalent means.
3. Connect the elastic element
40
with the ink cartridge
10
. Pull the elastic element
40
and the plate
50
away from the ink cartridge
10
.
4. Insert the bag. With reference to
FIG. 3
, the airbag is mounted by pressing the buckle ring
30
on the bag so that the protruding part
32
is embedded into the little hole
11
preserved on the ink cartridge
10
.
5. Release the elastic element
40
and the plate
50
. The plate
50
depresses the bag so that the airbag tends to shrink inside the cartridge.
The steps 1 and 2 can be processed at the same time on different assembly lines. Steps 3 and 4 can be interchanged in order without departing from the spirit of the invention.
With simultaneous reference to
FIGS. 4 and 5
, the ink consumption during normal inkjet printing processes increases the negative pressure inside the ink cartridge so that the atmospheric pressure becomes larger. Therefore, the ambient air goes into the airbag
20
,
60
through the vent hole
31
. This increases the volume of the airbag
20
,
60
to balance the negative pressure, keeping the negative pressure within a normal range. To avoid an extreme operating environment, the airbag
20
,
60
or the ink cartridge
10
can be formed with an additional bubble generator
12
,
21
so that when the pressure difference becomes too large, the air can enter through the bubble generator
12
,
21
. Since the principle and technique of the bubble generator
12
,
21
are well-known, we do not repeat them herein.
Improvement Results
The invention provides a negative pressure adjusting airbag that can be embedded in an ink cartridge and the assembly method therefor. Steps 1 and 2 mentioned above can be performed separately and simultaneously at different places or assembly lines. This makes the production arrangement more flexible. The connection of the airbag and the ink cartridge can be easily achieved by pressing. The invention is very different from the conventional ink cartridge assembly procedure.
Claims
- 1. An embedding-type negative pressure-regulating airbag for an ink cartridge comprising:an airbag being a bag with a variable volume; a buckle ring tightly connected to the airbag and has a protruding part that is to be embedded in a little hole preserved on the ink cartridge, the center of the buckle ring having a vent hole for air to enter or escape; an elastic element, including two torsion spring, one end of each torsion spring is connected with each other and the other end of each torsion spring is connected to the ink cartridge; and a plate connected with said end of the torsion spring for transferring a spring force to depress the airbag.
- 2. The embedding-type negative pressure-regulating airbag of claim 1, wherein the airbag has a bubble generator for air to enter from the airbag to the ink cartridge.
- 3. The embedding-type negative pressure-regulating airbag of claim 1, wherein the ink cartridge has a bubble generator for air to enter from its outside into its inside.
- 4. An assembly method for an embedding-type negative pressure-regulating airbag for an ink cartridge comprising the steps of:preparing a buckle with a protruding part and a vent hole for connection with a bag with a variable volume; preparing a plate connecting to one end of an elastic element; preparing an ink cartridge, which is preserved with a little hole and connected with the other end of the elastic element, and pulling the elastic element and the plate away from the ink cartridge; inserting the bag and pressing the buckle ring so that the protruding part is embedded in the preserved little hole, thereby connecting the bag with the ink cartridge; and releasing the elastic element and the plate for the elastic element to depress the bag through the plate, so that the volume of the bag tends to shrink.
- 5. The assembly method of claim 4, wherein the buckle ring is made of a material selected from the group consisting of the same material as the bag surface and materials that are easy to assemble and produced by ejection.
- 6. The assembly method of claim 4, wherein the buckle is connected to the bag by surface mounting.
- 7. The assembly method of claim 4, wherein the buckle ring is connected to the bag by a means selected from the group consisting of thermal bonding and vibration welding.
- 8. An assembly method for an embedding-type negative pressure-regulating airbag for an ink cartridge comprising the steps of:preparing a buckle ring with a protruding part and a vent hole for connection with a bag with a variable volume; preparing an ink cartridge preserved with a little hole and inserting the bag, pressing the buckle ring so that the protruding part is embedded into the little hole, thereby connecting the bag with the ink cartridge; preparing a plate connecting to one end of an elastic element; and connecting the other end of the elastic element with the ink cartridge so that the elastic element depresses the bag through the plate, the volume of the bag tending to shrink.
- 9. The assembly method of claim 8, wherein the buckle ring is made of a material selected from the group consisting of the same material as the bag surface and materials that are easy to assemble and produced by ejection.
- 10. The assembly method of claim 8, wherein the buckle ring is connected to the bag by surface mounting.
- 11. The assembly method of claim 8, wherein the buckle ring is connected to the bag by a means selected from the group consisting of thermal bonding and vibration welding.
Priority Claims (1)
Number |
Date |
Country |
Kind |
90132896 A |
Dec 2001 |
TW |
|
US Referenced Citations (7)