Apparatus and method for joining a coupler and a flow tube to an ultrasonic flowmeter

Abstract

1. A flow sensor subassembly for sensing the flow of a fluid drug, the flow sensor subassembly comprising: a flow tube having an inlet and an outlet; a first coupler secured to the inlet of the flow tube; a second coupler secured to the outlet of the flow tube; a first piezoelectric element secured to the first coupler; a second piezoelectric element secured to the second coupler to define a predetermined distance between the first piezoelectric element and the second piezoelectric element; and at least one absorbent sleeve engaged with the first coupler, the flow tube, and the second coupler.

Description

Technical Field

[0001] This application claims the benefit of U.S. Provisional Application No. 62 / 964,309, filed on January 22, 2020, entitled "Apparatus and Method for Joining a Coupler and a Flow Tube to an Ultrasonic Flow Meter", the entire disclosure of which is hereby incorporated by reference in its entirety.

Background Art

[0002] This application generally relates to a flow sensor subassembly for sensing the flow of fluid pharmaceuticals. Description of Related Art

[0003] Referring to FIGS. 1 and 2, a flow sensor system 1 that utilizes an ultrasonic flow meter includes a flow tube subassembly 2 having two piezoelectric transducers 4 coupled to a fluid flow tube 6. The transducers 4 are attached to first and second couplers 7, 8, respectively, with the flow tube 6 attached to the couplers 7, 8. When the transducers 4 are excited by an electrical pulse, ultrasonic waves are transmitted through the fluid and the flow tube 6. The system analyzes the waves moving through the fluid to determine the velocity, which is proportional to the shift between the signal received from the upstream transducer and the signal received from the downstream transducer. Waves or signals moving within the flow tube material are undesirably "treaded" as signal noise. The flow tube subassembly 2 includes an absorption tube 9 disposed across the flow tube 6 between the couplers 7, 8. The ultrasonic energy moving through the flow tube 6 is reduced by the absorption tube 9. The system 1 of FIGS. 1 and 2 can be the flow sensor system of U.S. Patent No. 9,970,794, which is hereby incorporated by reference in its entirety.

Summary of the Invention

[0004] In one aspect or embodiment, a flow sensor subassembly for sensing the flow of a fluid pharmaceutical includes a flow tube having an inlet and an outlet, a first coupler fixed to the inlet of the flow tube, a second coupler fixed to the outlet of the flow tube, a first piezo element fixed to the first coupler, a second piezo element fixed to the second coupler to define a predetermined distance between the first piezo element and the second piezo element, and at least one absorption sleeve engaged with the first coupler, the flow tube, and the second coupler.

[0005] The at least one absorption sleeve may include a first absorption sleeve engaged with the first coupler and the flow tube, and a second absorption sleeve engaged with the second coupler and the flow tube, and the first absorption sleeve is spaced apart from the second absorption sleeve to define a gap. The flow tube may not be covered by any absorption material within the gap between the first absorption sleeve and the second absorption sleeve. The first absorption sleeve and the second absorption sleeve may each cover at least 10% of the length of the flow tube between the first coupler and the second coupler. The first absorption sleeve and the second absorption sleeve may each cover 25% of the length of the flow tube between the first coupler and the second coupler. The at least one absorption sleeve may include thermoplastic polyurethane, and the flow tube may include stainless steel.

[0006] The flow tube may be fixed to the first coupler and the second coupler via at least one absorption sleeve. The interface between the first and second couplers and the flow tube may not include an adhesive.

[0007] The at least one absorption sleeve may be press-fitted onto the first and second couplers and the flow tube. The at least one absorption sleeve may be adhered to the first and second couplers and the flow tube. The at least one absorption sleeve may be overmolded onto the first and second couplers and the flow tube.

[0008] In one aspect or embodiment, a flow sensor subassembly for sensing the flow of a fluid pharmaceutical includes a flow tube having an inlet and an outlet, a first coupler fixed to the inlet of the flow tube, a second coupler fixed to the outlet of the flow tube, a first piezo element fixed to the first coupler, a second piezo element fixed to the second coupler for defining a predetermined distance between the first piezo element and the second piezo element, and at least one absorption sleeve, and the flow tube is engaged with the first coupler and the second coupler via at least one absorption sleeve.

Brief Description of the Drawings

[0009] The above and other features and advantages of the present disclosure, and the manner of achieving them, will become more apparent and the present disclosure itself will be better understood by reference to the following description of embodiments of the present disclosure taken in conjunction with the accompanying drawings.

[0010]

Fig. 1

Fig. 2

Fig. 3

Fig. 3A

Fig. 3B

Fig. 4

Fig. 5

[0011] Corresponding reference numerals indicate corresponding parts throughout the several views. The examples presented in this specification are illustrative of exemplary embodiments of the present disclosure and such examples should not be construed as limiting the scope of the present disclosure in any way.

Best Mode for Carrying Out the Invention

[0012] The following description is provided to enable one of ordinary skill in the art to make and use the described embodiments contemplated for carrying out the present invention. However, various modifications, equivalents, variations, and alternatives will be readily apparent to one of ordinary skill in the art. Any and all such modifications, variations, equivalents, and alternatives are intended to fall within the spirit and scope of the present invention.

[0013] For the purposes of the following description, the terms “upper,” “lower,” “right,” “left,” “vertical,” “horizontal,” “uppermost,” “lowermost,” “lateral,” “longitudinal,” and derivatives thereof shall relate to the present invention as oriented in the drawings. However, it will be understood that the present invention may contemplate various alternative variations unless explicitly specified to the contrary. It should also be understood that the specific devices shown in the accompanying drawings and described in the following specification are merely exemplary embodiments of the present invention. Therefore, specific dimensions and other physical characteristics related to the aspects disclosed herein should not be considered limiting. All numbers and ranges used in this specification and the claims are to be understood as being modified in all instances by the term “about.” “About” means plus or minus 25 percent of the recited value, e.g., plus or minus 10 percent of the recited value. However, this should not be considered limiting to any analysis of values under the theory of equivalents.

[0014] Unless otherwise indicated, all ranges or ratios disclosed in this specification are to be understood to encompass the starting and ending values, as well as any and all sub-ranges or sub-ratios included therein. For example, a specified range or ratio of "1 to 10" should be considered to include all sub-ranges or sub-ratios (including) between the minimum value of 1 and the maximum value of 10. That is, all sub-ranges or sub-ratios begin with a minimum value of 1 or more and end with a maximum value of 10 or less. The ranges and / or ratios disclosed in this specification represent average values over the specified ranges and / or ratios.

[0015] The terms "first", "second", etc. are not intended to refer to any particular order or chronology, but rather to different conditions, characteristics, or elements.

[0016] Referring to FIGS. 3, 3A, and 3B, a flow sensor subassembly 10 for sensing the flow of a fluid pharmaceutical includes a flow tube 12 having an inlet 14 and an outlet 16, a first coupler 18 fixed to the inlet 14 of the flow tube 12, a second coupler 20 fixed to the outlet 16 of the flow tube 12, a first piezo element 22 fixed to the first coupler 18, a second piezo element 24 fixed to the second coupler 20 to define a predetermined distance D between the first piezo element 22 and the second piezo element 24, and at least one absorption sleeve 26 engaged with the first coupler 18, the flow tube 12, and the second coupler 20. Providing at least one absorption sleeve 26 that engages the first coupler 18, the flow tube 12, and the second coupler 20, as opposed to providing the absorption sleeve 26 only on the flow tube and not contacting or engaging the first and second couplers 18, 20, reduces the amount of ultrasonic energy transmitted to the material of the flow tube 12 via the first and second couplers 18, 20, thereby reducing the amount of signal noise. The flow sensor subassembly 10 can be utilized in connection with the flow sensor system 1 of FIG. 1, although the flow sensor subassembly 10 can be utilized with other suitable flow sensor systems.

[0017] As shown in FIGS. 3, 3A, and 3B, in one aspect or embodiment, at least one absorption sleeve 26 includes a first absorption sleeve 28 that engages a first coupler 18 and a flow tube 12, and a second absorption sleeve 30 that engages a second coupler 20 and the flow tube 12. The first absorption sleeve 28 is spaced apart from the second absorption sleeve 30 to define a gap 32. The flow tube 12 is not covered by any absorption material within the gap 32 between the first absorption sleeve 28 and the second absorption sleeve 30. The first absorption sleeve 28 engages both the first coupler 18 and the flow tube 12 directly. The second absorption sleeve 30 engages both the second coupler 20 and the flow tube 12 directly.

[0018] In another aspect or embodiment, rather than providing a first absorption sleeve 28 and a second absorption sleeve 30, at least one absorption sleeve 26 includes a single piece of material that engages the first coupler 18, extends along the flow tube 12, and engages the second coupler 20.

[0019] In one aspect or embodiment, each of the first absorption sleeve 28 and the second absorption sleeve 30 covers at least 10% of the length of the flow tube 12 between the first coupler 18 and the second coupler 20. In one aspect or embodiment, each of the first absorption sleeve 28 and the second absorption sleeve 30 covers 25% of the length of the flow tube 12 between the first coupler 18 and the second coupler 20. In one aspect or embodiment, each of the first absorption sleeve 28 and the second absorption sleeve 30 has an outer diameter of 6.2 mm, an inner diameter on the 1.38 mm flow tube 12, and an inner diameter across the first and second couplers 18, 20 of 2.91 mm. In one aspect or embodiment, a 12 mm long flow tube 12 is in direct contact with each of the first absorption sleeve 28 and the second absorption sleeve 30.

[0020] In one aspect or embodiment, at least one absorption sleeve 26 is made of thermoplastic polyurethane, and the flow tube 12 is made of stainless steel. The thermoplastic polyurethane can be Pellethane® from Lubrizol. The thermoplastic polyurethane can have a Shore hardness in the range of 53D - 76D or 80A - 91A as tested in accordance with ASTM D2240. In one aspect or embodiment, at least one absorption sleeve 26 is made of Pellethane® 2363 - 55DE from Lubrizol. Other materials with suitable acoustic attenuation properties, such as polyoxymethylene (POM), can also be utilized.

[0021] Referring again to FIGS. 3, 3A, and 3B, the flow tube 12 is fixed to the first coupler 18 and the second coupler 20 via at least one absorption sleeve 26. More specifically, in one aspect or embodiment, there is no direct connection fixed between the first and second couplers 18, 20 and the flow tube 12 such that the first and second couplers 18, 20 are not constrained with respect to the flow tube 12, thereby increasing the intensity of the ultrasonic waves. The interface between the first and second couplers 18, 20 and the flow tube 12 does not include an adhesive, and at least one absorption sleeve fixes the first and second couplers 18, 20 to the flow tube 12.

[0022] In one aspect or embodiment, at least one absorption sleeve 26 is press - fit into the first and second couplers 18, 20, and the flow tube 12. In one aspect or embodiment, at least one absorption sleeve 26 is adhered to the first and second couplers 18, 20, and the flow tube 12. In one aspect or embodiment, at least one absorption sleeve 26 is overmolded onto the first and second couplers 18, 20, and the flow tube 12. Various combinations of these and other fixing techniques can be utilized to fix at least one absorption sleeve 26 to the first and second couplers 18, 20 and the flow tube 12.

[0023] Referring to FIGS. 4 and 5, a graph of signal level versus time is shown comparing the flow tube subassembly 10 of FIG. 3 with a conventional flow tube subassembly. As shown in FIG. 4, the signal level of the energy coming through the fluid of the flow tube subassembly 10 of FIG. 3 is high compared to a conventional flow tube subassembly. Further, as shown in FIG. 5, the noise level of the energy coming through the flow tube 12 of the flow tube subassembly 10 of FIG. 3 is low compared to a conventional flow tube subassembly.

[0024] Accordingly, the flow tube subassembly 10 of the present application improves the signal-to-noise ratio by providing a higher flow signal and a lower flow tube noise signal compared to a conventional flow tube subassembly. The flow tube subassembly 10 also eliminates the need for a separate assembly method between the couplers 18, 20 and the flow tube 12.

[0025] Although the present disclosure has been described as having an exemplary structure, the present disclosure can be further modified within the spirit and scope of the present disclosure. Accordingly, this application intends to cover any variations, uses, or adaptations of the present disclosure using its general principles. As far as possible, one or more features of any embodiment or aspect can be combined with one or more features of any other embodiment or aspect. Further, this application intends to cover departures from the present disclosure that fall within the scope of the appended claims within the known or customary scope of the art to which the present disclosure pertains.

Claims

1. A flow sensor subassembly for sensing the flow of a fluid medicament, comprising: a flow tube having an inlet and an outlet; a first coupler fixed to the inlet of the flow tube; a second coupler fixed to the outlet of the flow tube; a first piezo element fixed to the first coupler; a second piezo element fixed to the second coupler for defining a predetermined distance between the first piezo element and the second piezo element; at least one absorption sleeve engaging at least the first coupler or the second coupler; wherein the at least one absorption sleeve covers at least a portion of the outer peripheral surface of the flow tube between the first and second couplers. A flow sensor subassembly as claimed in claim 1, wherein the at least one absorption sleeve covers at least a portion of the outer peripheral surface of the flow tube between the first and second couplers.

2. The flow sensor subassembly according to claim 1, wherein the at least one absorption sleeve comprises a first absorption sleeve engaging the first coupler and the flow tube, and a second absorption sleeve engaging the second coupler and the flow tube, and the first absorption sleeve is spaced from the second absorption sleeve to define a gap.

3. The flow sensor subassembly according to claim 2, wherein the flow tube is not covered by any absorption material within the gap between the first absorption sleeve and the second absorption sleeve.

4. The flow sensor subassembly according to claim 2, wherein the first absorption sleeve and the second absorption sleeve each cover at least 10% of the length of the flow tube between the first and second couplers.

5. The flow sensor subassembly according to claim 4, wherein the first absorption sleeve and the second absorption sleeve each cover 25% of the length of the flow tube between the first and second couplers.

6. The flow sensor subassembly according to any one of claims 1 - 5, wherein the at least one absorption sleeve comprises thermoplastic polyurethane and the flow tube comprises stainless steel.

7. The flow sensor subassembly according to any one of claims 1 - 6, wherein the flow tube is fixed to the first coupler and the second coupler via the at least one absorption sleeve.

8. The flow sensor subassembly according to any one of claims 1-7, wherein there is no adhesive at the interface between the first and second couplers and the flow tube.

9. The flow sensor subassembly according to any one of claims 1-8, wherein the at least one absorption sleeve is press-fitted into the first and second couplers and the flow tube.

10. The flow sensor subassembly according to any one of claims 1-9, wherein the at least one absorption sleeve is adhered to the first and second couplers and the flow tube.

11. The flow sensor subassembly according to any one of claims 1-9, wherein the at least one absorption sleeve is overmolded onto the first and second couplers and the flow tube.

12. A flow sensor subassembly for sensing the flow of a fluid medicament, a flow tube having an inlet and an outlet, a first coupler fixed to the inlet of the flow tube, a second coupler fixed to the outlet of the flow tube, a first piezo element fixed to the first coupler, a second piezo element fixed to the second coupler for defining a predetermined distance between the first piezo element and the second piezo element, a plurality of absorption sleeves, comprising, the plurality of absorption sleeves being fixed to at least one of the first coupler and the second coupler, The flow sensor subassembly, wherein the plurality of absorption sleeves cover at least a portion of the outer peripheral surface of the flow tube between the first and second couplers.

13. The flow sensor subassembly according to claim 12, wherein the plurality of absorption sleeves comprises a first absorption sleeve engaging the first coupler and the flow tube and a second absorption sleeve engaging the second coupler and the flow tube, and the first absorption sleeve is spaced from the second absorption sleeve to define a gap.

14. The flow sensor subassembly according to claim 13, wherein the flow tube is not covered by any absorption material within the gap between the first absorption sleeve and the second absorption sleeve.

15. The flow sensor subassembly according to claim 13, wherein the first absorption sleeve and the second absorption sleeve each cover at least 10% of the length of the flow tube between the first and second couplers.

16. The flow sensor subassembly according to claim 15, wherein the first absorption sleeve and the second absorption sleeve each cover 25% of the length of the flow tube between the first and second couplers.

17. The flow sensor subassembly according to any one of claims 12 - 16, wherein the plurality of absorption sleeves comprise thermoplastic polyurethane and the flow tube comprises stainless steel.

18. The flow sensor subassembly according to any one of claims 12 - 17, wherein there is no adhesive at the interface between the first and second couplers and the flow tube.

19. The flow sensor subassembly according to any one of claims 12 - 18, wherein the plurality of absorption sleeves are press - fitted into the first and second couplers and the flow tube.

20. The flow sensor subassembly according to any one of claims 12 - 19, wherein the plurality of absorption sleeves are adhered to the first and second couplers and the flow tube.

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