Patent Application
20070289375
The following detailed description of specific embodiments of the present invention can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:
Referring to
The conductors 22 are configured to extend along a longitudinal axis of the probe body 20 and are embedded within the dielectric body portion 26 such that the conductors 22 are electrically isolated from each other by the dielectric body portion 26. More specifically, as shown in
Similar to the conductors 22, the fluid channel 24 is configured to extend along the longitudinal axis of the probe body 20, within the dielectric body portion 26. The probe body 20 is configured to pass fluid 10 through this fluid channel 24. Meanwhile, the dielectric body portion 26 generally is configured of a polymer material. For example, the dielectric body portion 26 can be configured of a fluoro-polymer material.
As also shown in
The fluid level sensing circuit electrically coupled to the conductors 22 generally is provided to monitor changes in an electrical signal across the conductors 22. For example, and not by way of limitation, the fluid level sensing circuit can be configured to monitor changes in conductivity or capacitance between the conductors and correlate the changes in conductivity or capacitance with the presence or absence of fluid at the sensing end 28 of the probe body 20. Thus, the fluid level sensing device of the present invention can be used to provide an indication of fluid level within the container 30 by correlating the presence or absence of fluid at the sensing end 28 of the probe body 20 with the height of the sensing end 28 within the container 30. A sensing circuit connector 40, shown in
Further, as shown in
The fluid level sensing device of the present invention may further comprise a mechanical arm or other similarly functioning device. This mechanical arm may be secured to the upper portion 20B of the probe body 20 such that the probe body 20 may be maneuvered by the mechanical arm. For example, the mechanical arm may be used to maneuver the probe body 20 from one container from which it aspirates fluid 10 to another container in which it dispenses said fluid 10.
Also shown in
Further, in another embodiment of the fluid level sensing device of the present invention where a probe body 20 is provided in a length insufficient to reach another device or system of the user, the fluid level sensing device may also comprise a tube fitting 50 and a length of tubing 52. As shown in
A fluid level may be recognized as low or high depending on whether the probe body 20 and the container 30 at least partially filled with fluid 10 serve as a supply system of fluid 10 or as a disposal system for waste material. In the context of a container 30 carrying a supply of fluid 10, the probe body 20 can be positioned at a relatively low level in the container 30 to provide signals indicative of relatively low fluid levels or an “empty” or “near empty” condition within the container 30 when the fluid level falls beneath the sensing end 28 of the lowly positioned probe body 20. Thus, the fluid level sensing device may indicate a low fluid level when a supply of fluid 10 is nearly expended and needs replenished. Alternatively, in the context of a container 30 being filled with waste material, or another type of fluid, the probe body 20 can be positioned at a relatively high level in the container 30 to provide signals indicative of relatively high fluid levels or a “full” or “nearly full” condition within the container 30 when the fluid level rises to reach the sensing end 28 of the highly positioned probe body 20. Thus, the fluid level sensing device may indicate a high fluid level when a level of waste material reaches a maximum fluid level of the container 30.
The fluid level sensing device of the present invention may further comprise a structural housing configured to provide greater dimensional stability to the probe body 20, if needed. Preferably, the housing is configured of stainless steel and is applied to the probe body such that the housing avoids substantial contact with fluids.
It is contemplated by the present invention that the conductors 22 may be provided to the probe body 20 in any configuration where the conductors 22 extend along the longitudinal axis of the probe body 20, are embedded within the dielectric body portion 26, and are electrically isolated from each other. By ways of example, but not of limitation, such configurations may be where the conductors 22 are parallel to each other and the fluid channel 24 or wrap helically about the fluid channel 24. For purposes of the present invention, the description that the conductors 22 and the fluid channel 24 extend along the longitudinal axis of the probe body 20 simply means that the conductors 22 and the fluid channel 24 extend from one end of the probe body 20 to the other. Thus, the conductors 22 and the fluid channel 24 may be, but are not necessarily, parallel to one another.
It is further contemplated by the present invention that the probe body 20 may be provided in a variety of configurations. For example, the probe body 20 and/or the fluid channel 24 may be provided in an angular or circular cross-sectional configuration, or combinations thereof. In addition, the probe body 20 and/or the fluid channel 24 may be configured with any diameter or width that is feasible through the process of co-extrusion or injection molding. Further, the probe body 20 may be provided in any length desired by a user of the fluid level sensing device according to the present invention. Thereby, the probe body 20 may be provided in a length sufficient to eliminate any need for the tube fitting 50 or the length of tubing 52 described herein.
The present invention further relates to a method of manufacturing a fluid level sensing device that comprises a probe body 20. This method comprises co-extruding a dielectric material and an electrically conductive material such that the probe body 20 is configured as an elongate member free of substantial fluid holding discontinuities. This probe body 20 comprises at least two conductors 22 formed of the electrically conductive material, a fluid channel 24, and a dielectric body portion 26 formed of the dielectric material. The configuration of this probe body 20 formed through this method is consistent with the probe body 20 embodiments described herein.
The method of manufacturing a fluid level sensing device according to the present invention forms a homogenous fluid level sensing probe body 20 that is free of substantial fluid holding discontinuities that may hold-up droplets of fluid 10 on the probe body 20. More specifically, the co-extrusion process of the present invention yields a probe body 20 that is not subject to post-manufacture creep or stress between plastic and metal components of the probe body 20. As a result, the probe body 20 of the present invention is less likely to include fluid holding discontinuities that would otherwise develop during and after probe manufacture. By using the process of co-extrusion, this method avoids the creation of these discontinuities and the risk of cross-contamination of fluids described above.
It is noted that terms like “preferably,” “commonly,” and “typically” are not utilized herein to limit the scope of the claimed invention or to imply that certain features are critical, essential, or even important to the structure or function of the claimed invention. Rather, these terms are merely intended to highlight alternative or additional features that may or may not be utilized in a particular embodiment of the present invention.
For the purposes of describing and defining the present invention it is noted that the term “device” is utilized herein to represent a combination of components and individual components, regardless of whether the components are combined with other components. For example, but not by way of limitation, a “device” according to the present invention may comprise a probe body 20, a container 30 at least partially filled with fluid 10, and a fluid level sensing circuit.
For the purposes of describing and defining the present invention it is noted that the term “substantially” is utilized herein to represent the inherent degree of uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The term “substantially” is also utilized herein to represent the degree by which a quantitative representation may vary from a stated reference without resulting in a change in the basic function of the subject matter at issue.
Having described the invention in detail and by reference to specific embodiments thereof, it will be apparent that modifications and variations are possible without departing from the scope of the invention defined in the appended claims. More specifically, although some aspects of the present invention are identified herein as preferred or particularly advantageous, it is contemplated that the present invention is not necessarily limited to these preferred aspects of the invention.
