Patent Description:
Fluid jetting technology is similar to inkjet technology, but is used to express fluids other than inks. For example, a fluid jet cartridge could express various combinations of one or more fluid medications, which could be delivered in a variety of different ways, such as via oral or nasal passages or tissues.

Fluid jetting technology uses, among other things, a cartridge that in its basic form is comprised of a reservoir and a jetting head. The reservoir holds the liquid to be expelled by the cartridge, which can be ink, but can also be other fluids. A given cartridge might have only a single reservoir with a single fluid to be ejected. However, another cartridge might have several reservoirs containing several different fluids to be ejected.

Regardless of the fluid to be expressed, it is possible for gas, such as air, to be entrained within the fluid reservoir in the cartridge. In most situations in which the cartridge is used, the jetting head is either below or horizontally adjacent the cartridge, and so any air or other gas that is entrained in the fluid does not naturally flow to the junction between the reservoir and the jetting head.

However, some situations require a jetting cartridge to express the fluid in a substantially vertically-upward direction, such as to a nasal cavity. In this configuration, any gas that is within the fluid reservoir of the cartridge will naturally flow up toward the jetting head. This condition tends to impede the fluid from flowing out of the reservoir and into the jetting head, thus rendering the cartridge inoperable.

<CIT> discloses a cartridge for jetting a fluid, the cartridge comprising a reservoir for holding and providing the fluid, a tower having an interior chamber for receiving the fluid from the reservoir and further providing the fluid.

What is needed, therefore, is something that tends to reduce issues such as those described above, at least in part.

The above and other needs are met by a cartridge for jetting a fluid. A reservoir holds and provides the fluid. A tower with an interior chamber receives the fluid from the reservoir and provides the fluid. The tower has a first end proximate the reservoir, a second end distal the reservoir, a port in the second end of the tower, and an interior for conducing the fluid from the reservoir. A first rib and a second rib extend along a length of the tower between the first and second ends of the tower, in the interior of the tower. A second end of the first rib and a second end of the second rib are substantially adjacent the second end of the tower, and the first rib extends along the length of the tower toward the first end of the tower, a first end of the first rib extends further than a first end of the second rib, and a length of the first rib is longer than a length of the second rib. A jetting head has a first via for receiving the fluid from the port, and the jetting head is configured for expressing the fluid from the cartridge. The second end of at least one of the first rib and the second rib at least partially overlaps the first via within the port and is spaced apart from the first via by a gap.

In various embodiments according to this aspect of the invention, the second ends of the first and second ribs are not parallel to a receiving surface of the jetting head in which the first via is formed. In some embodiments, the tower includes a third rib that extends to a different distance than either the first rib or the second rib along the length of the tower. In some embodiments, the gap is from about three hundred microns to about five hundred microns. In some embodiments, the jetting head includes a second via, and the first rib at least partially overlaps the first via and the second rib at least partially overlaps the second via. In some embodiments, the cartridge is a nasal drug delivery cartridge. In some embodiments, flow channels are formed between the first rib and the second rib, and the flow channels tend to trap and retain gas bubbles therewithin, such that the gas bubbles are prevented from aspirating into the first via when the cartridge is oriented with the tower above the reservoir. In some embodiments, the first via and the second ends of both the first and second ribs are oriented substantially parallel one to another. In some embodiments, the first via and the second ends of both the first and second ribs are and the second ends of the first and second ribs are oriented substantially perpendicularly one to another.

Further advantages of the invention are apparent by reference to the detailed description when considered in conjunction with the figures, which are not to scale so as to more clearly show the details, wherein like reference numbers indicate like elements throughout the several views, and wherein:.

With reference now to <FIG>, there is depicted a partial side cross-sectional view of a cartridge <NUM> in a downward orientation, such as a maintenance orientation, according to a first embodiment of the present invention. The cartridge <NUM> comprises the reservoir <NUM>, a tower <NUM>, and a jetting head <NUM>. Additional descriptions in regard to each of these basic elements of the cartridge <NUM> are provided below.

The reservoir <NUM> contains one or more chambers with one or more fluids to be expressed by the jetting head <NUM>. Although the embodiments of the present invention are applicable to cartridges <NUM> that express more than one fluid, the embodiments described herein express only a single fluid, so to not unnecessarily encumber the drawings. But it is understood that a greater number of fluids is contemplated.

The tower <NUM> conducts the fluid to be expressed from the reservoir <NUM> to the jetting head <NUM> through a filter <NUM> that is attached to the reservoir <NUM> with an attachment surface <NUM>. The tower <NUM> is that portion of the cartridge <NUM> between the filter <NUM> and the jetting head <NUM>. As can be seen in <FIG>, there may be one or more gas bubbles 104a and 104b entrained in the fluid. When the cartridge <NUM> is disposed with the tower <NUM> in downward orientation, the gas bubbles 104a and 104b tend to stay near the end of the tower <NUM> that is proximate the reservoir <NUM> and filter <NUM>. When the gas bubbles 104a and 104b are in this position, they do not pose much of a problem to the proper flow of the fluid from the reservoir <NUM> to the jetting head <NUM>.

However, when the cartridge <NUM> is inverted, as depicted in <FIG>, with the tower <NUM> in an upward orientation, such as in a delivery orientation, the gas bubbles 104a and 104b tend to migrate near the end of the tower <NUM> that is distal the reservoir <NUM> and filter <NUM>. As can be seen in <FIG>, the smaller gas bubble 104b has moved to the distal end, but to a position in which it does not interfere to a destructive degree with the flow of the fluid to the jetting head <NUM>. The larger gas bubble 104a has not moved to the distal end in the embodiment depicted in <FIG>.

The reason that neither of the gas bubbles 104a and 104b have moved into a position in which they substantially impede the flow of the fluid from the reservoir <NUM> to the jetting head <NUM>, is the presence of ribs <NUM> in the tower <NUM>, which ribs <NUM> create flow channels within the tower <NUM>. The ribs <NUM> may be placed, in one embodiment, so as to create flow channels of various sizes between the ribs <NUM> and within the tower <NUM>. Gas bubbles 104a and 104b tend to flow through whichever flow channel within the tower <NUM> that will accommodate the size of the particular gas bubble 104a and 104b, and then stay there, allowing the fluid to flow through other flow channels that were too small to pass the gas bubble 104a and 104b.

In various embodiment, the ribs <NUM> are placed at different angles with regard to the surface of the chip <NUM>. In some embodiment, the ribs <NUM> are disposed at an angle of about five degrees from perpendicular with respect to the surface of the chip <NUM>. In other embodiments they may be disposed at a different angle, and in other embodiments they may be substantially perpendicular to the surface of the chip <NUM>.

So, as depicted in <FIG>, the larger gas bubble 104a cannot move up through any of the flow channels between the ribs <NUM>, but is trapped by the end of one of the ribs <NUM>, while the fluid flows past the gas bubble 104a in the other flow channels. The smaller gas bubble 104b is small enough the flow completely up through one of the flow channels that is formed between the ribs <NUM>, but then is trapped by its size within that flow channels by the proximity of the ribs <NUM>, once again allowing the fluid to flow to the jetting head <NUM> through others of the flow channels between the ribs <NUM>.

In this manner, by the placement of ribs <NUM> in the tower <NUM>, flow channels are formed that tend to trap and retain gas bubbles 104a and 104b within them, thus preventing the gas bubbles 104a and 104b from attaining a position adjacent the jetting head <NUM> and cutting off the flow of the fluid to the jetting head <NUM>. Different embodiments and views of the ribs <NUM> are described below, so as to provide a better comprehension of the embodiments of the invention.

With reference now to <FIG>, there is depicted a top perspective view of the interior of a cartridge <NUM> according to a first embodiment of the present invention. This view looks down through the reservoir <NUM> to see the ribs <NUM> in the tower <NUM>. In this embodiment, the ribs <NUM> form the four arms of a cross within the tower <NUM>, with a void in the middle of the cross, so that none of the four arms meet with one another. Thus, flow channels are formed in the spaces between all of the ribs <NUM>. <FIG> provides another top view of the ribs <NUM>.

With reference now to <FIG>, there is depicted a partial side perspective cross-sectional view of a cartridge <NUM> in a downward orientation according to the first embodiment of the present invention. In this embodiment, the ribs <NUM> extend to different lengths from the distal end of the tower <NUM> toward the reservoir <NUM>. These different lengths create partial flow channels at the ends of the ribs <NUM>, which can accommodate larger gas bubbles 104a and 104b, while smaller gas bubbles 104a and 104b can travel through the flow channels formed between the ribs <NUM>. Thus, in some embodiments, all of the ribs <NUM> may have different lengths, and in other embodiments, all of the ribs <NUM> may have the same length. In some embodiments the ribs <NUM> may all extend to what can be termed the top or the proximate end of the tower <NUM>, and in other embodiments the ribs <NUM> may extend to different lengths, as depicted in <FIG>.

With reference now to <FIG>, there is depicted a bottom plan view of the exterior of a cartridge <NUM> according to the first embodiment of the present invention. In this view, the jetting head <NUM> is not attached, so as to show some of the detail of the ribs <NUM> that is visible through the fluid passage at the distal end of the tower <NUM>. As can be seen, some of the ribs <NUM> block some of the fluid passage, but do not completely block it. <FIG> provides an enlarged portion of the same view as <FIG>, where the ends of the ribs <NUM> can be more easily seen through the fluid passage in the tower <NUM>.

With reference now to <FIG>, there is depicted a top perspective view of the interior of a cartridge <NUM> according to a second embodiment of the present invention. In this embodiment, there is a different orientation of the ribs <NUM>. For example, this second embodiment still has four ribs <NUM>, but they are disposed parallel to each other, instead of in the cross pattern of the first embodiment. <FIG> provide different views of this second embodiment, so that it can be better understood.

It is thus appreciated that the invention is not limited to a specific number of ribs <NUM>, a specific orientation of the ribs <NUM>, or a specific combination of the heights of the ribs <NUM>. Further, the ribs <NUM> are not confined to either a crossed or parallel orientation with respect to one another, but in some embodiments, they may not have equal angles between them, from one rib <NUM> to another.

With reference now to <FIG>, there is depicted an expanded partial side perspective cross-sectional view of a cartridge <NUM>, including the tower <NUM>, two ribs <NUM>, and the chip layer of a jetting head <NUM>, all in a downward orientation according to the second embodiment of the present invention. In the embodiment depicted in this view, the distal ends of the ribs <NUM> form a gap <NUM> above the vias <NUM> in the chip <NUM>. In some embodiments, the gap <NUM> may be from about three hundred microns to about five hundred microns in size. Thus, the ribs <NUM> allow the fluid to be expressed to flow through the gap <NUM> and into the vias <NUM> and, in this manner, do not interfere with the flow of the fluid from the tower <NUM> into the jetting head <NUM>.

With reference now to <FIG>, there is depicted a partial cross-sectional view of the distal end of the tower <NUM>, at the point of attachment of the tower <NUM> to the chip <NUM>, similar to that as depicted near the bottom of <FIG>. In this enlarged view, it is easier to see the relationship between the ends of the ribs <NUM> proximate the surface of the chip <NUM>, and the vias <NUM> that are formed in the chip <NUM>.

As depicted in <FIG>, the ribs <NUM> have ends proximate the surface of the chip <NUM>, which ends in some embodiments may not be flat and may not be parallel to the surface of the heater chip <NUM> over which they lie. In the embodiment depicted in <FIG>, the end of the rib <NUM> on the left-hand side is somewhat pointed or rounded, such that the center portion of the rib <NUM> that directly overlies the left-hand via <NUM> is a bit closer to the surface of the chip <NUM> than the two sides of the end of the left-hand rib <NUM>. In other embodiments, the end of the rib <NUM> on the right-hand side of <FIG> may be slanted such that one side of the end of the rib <NUM> is farther away from the surface of the chip <NUM> than the other side. In this manner, any gas bubble 104a or 104b that might attain a position as the end of the rib <NUM> while in the jetting orientation (upward), would tend to roll off the end of the rib <NUM> while in the maintenance orientation (downward).

In some embodiments, the ends of the ribs <NUM> may be disposed parallel to and partially overlying the vias <NUM>. In this manner, the gas bubbles 104a and 104b that are displaced by the ribs <NUM> tend to not find their way into the vias <NUM>, where they could be aspirated through the jetting head <NUM>.

Claim 1:
A cartridge (<NUM>) for jetting a fluid, the cartridge comprising:
a reservoir (<NUM>) for holding and providing the fluid,
a tower (<NUM>) having an interior chamber for receiving the fluid from the reservoir (<NUM>) and further providing the fluid, the tower (<NUM>) comprising,
a first end proximate the reservoir (<NUM>),
a second end distal the reservoir (<NUM>),
a port in the second end of the tower (<NUM>),
an interior for conducing the fluid from the reservoir (<NUM>),
a first rib and a second rib (<NUM>) extending along a length of the tower (<NUM>) between the first and second ends of the tower (<NUM>), and in the interior of the tower (<NUM>),
a second end of the first rib and a second end of the second rib are substantially adjacent the second end of the tower (<NUM>), and
the first rib extends along the length of the tower (<NUM>) toward the first end of the tower (<NUM>), the cartridge (<NUM>) being characterized in that
a first end of the first rib extends further than a first end of the second rib, and a length of the first rib is longer than a length of the second rib, and
a jetting head (<NUM>) having a first via (<NUM>) for receiving the fluid from the port, and the jetting head (<NUM>) is configured for expressing the fluid from the cartridge,
wherein the second end of at least one of the first rib and the second rib at least partially overlaps the first via (<NUM>) within the port, and is spaced apart from the first via (<NUM>) by a gap (<NUM>).