Patent Grant
10794375
The present invention is generally directed to miniature vacuum/pressure diaphragm pumps and more particularly to such pumps that are used to provide negative pressure wound therapy and/or monitoring, other patient therapy or monitoring.
Miniature vacuum diaphragm pumps heretofore have been used in negative pressure wound therapy (NPWT). The pump typically is connected to a semi-occluded or occluded therapeutic member, such as a compressible wound dressing. In other applications, the pump can be configured to supply positive pressure to another therapeutic member, such as an inflatable cuff for various medical therapies.
A problem with known miniature vacuum/pressure diaphragm pumps is that they produce noise at a volume level and/or frequencies that can be annoying and/or disruptive to the patient being treated or monitored. The noise, for instance, may interfere with the patient's sleeping.
The present invention provides a novel noise mitigation boot that can be installed on or integrated with a miniature diaphragm pump to reduce the overall noise and improve sound quality during operation. The boot, in particular a muffler wall, can reduce pneumatic noise or mechanical noise, or both as is preferred. The boot and more particularly the muffler wall may alter the frequencies of the noise to make the noise less annoying. A noise mitigation boot and miniature diaphragm pump according to the invention may have application to negative pressure wound therapy and/or monitoring, other patient therapy or monitoring, and other pressure and vacuum applications such as agent detection, air monitoring, surgical procedures, pain relief systems and personal safety equipment.
According to one aspect of the invention, a diaphragm pump assembly comprises a diaphragm pump, and a muffler wall disposed on at least one side of the diaphragm pump. The diaphragm pump includes a housing having first and second ports and an interior chamber, a pumping diaphragm disposed in the interior chamber and dividing the interior chamber into a pumping chamber and a backside chamber, a motor for reciprocating the pumping diaphragm for pumping air into and out of the pumping chamber, and flow passages connecting the pumping chamber to the first and second ports. The second port opens to an exterior surface of the housing, and the muffler wall overlies the exterior surface of the housing. The wall has formed therein a passage extending from the second port to the backside chamber for effecting fluid communication between the second port and the backside chamber.
In an embodiment, the muffler wall is part of a noise mitigation boot attached to the diaphragm pump.
In an embodiment, the first port is configured for attachment to a flow line.
The passage preferably follows a serpentine path having back and forth sections.
The passage preferably is formed by a groove in an interior surface of the muffler wall that is in juxtaposition with the exterior surface of the housing.
The backside chamber can open, at an end thereof opposite the pumping diaphragm, to the exterior surface of the housing at an opening, and the groove can have a portion thereof overlapped by the opening.
A plurality of the back and forth sections communicate directly with the backside chamber.
The noise mitigation boot preferably is made of an elastomeric material, in particular butyl or chloroprene rubber, that can have a Shore A durometer hardness of between 40 and 80, preferably between 50 and 70, and more preferably between 55 and 65. The elastomeric material preferably functions as a noise absorber and may also contribute to alteration of the frequencies of the noise generated by the pump.
The muffler wall can be pressed flush with the exterior surface.
The noise mitigation boot can have a plurality of side walls joined to the muffler wall, and the side walls can have interior surfaces pressed flush with respective exterior surfaces of the housing.
The side walls can be stretched around the side walls of the housing for holding the noise mitigation boot on the housing.
The noise mitigation boot can form a seal around the perimeter of the pump but still allows some infiltration of air between the noise mitigation boot and the housing.
At least one exhaust vent can be provided in the noise mitigation boot for allowing the infiltration of air into the interior of the boot for communication with the backside chamber.
The first port can have a tubular extension, preferably provided with a barb, projecting from the housing and though an opening in the noise mitigation boot that is sealed around the tubular extension.
The invention also provide a noise mitigation boot including one or more of the aforesaid features.
The foregoing and other features of the invention are hereinafter described in greater detail with reference to the accompanying drawings.
In the discussion above and to follow, the terms “upper”, “lower”, “top”, “bottom,” “end,” “inner,” “left,” “right,” “level,” “above,” “below,” “horizontal,” “vertical,” etc. refer to an exemplary diaphragm pump assembly oriented as shown in
Referring now in detail to
With additional reference to
The diaphragm pump 22 further includes a motor 42 for reciprocating the pumping diaphragm 36 for pumping air into and out of the pumping chamber 38, and flow passages 44 and 46 connecting the pumping chamber to the first and second ports 30 and 32. The motor can be of any suitable type such as an electric rotary motor, a linear actuator such as a solenoid, etc.
In the illustrated embodiment, an electric rotary motor is used. The motor can be powered to drive an eccentric 48 that reciprocates a plunger 50 back and forth for reciprocating the pumping diaphragm back and forth. This motion in one direction (intake/expansion stroke) increases the pumping chamber volume for drawing air into the pumping chamber via one of the flow passages. Motion in the reverse direction (outflow/compression stroke) for forcing the air out of the pumping chamber via the other of the flow passages. The flow passages 44 and 46 may include respective check valves 52 and 54 so that air can flow through the passages only in one direction. In alternative arrangement, one or both check valves may be provided in respective external flow lines connected to the ports.
The diaphragm pump 20 may be configured for use as either a vacuum pump or a pressure pump. In the illustrated embodiment, the diaphragm pump is configured for use as a vacuum pump. To this end, first (or intake) port 30 is configured for attachment to a vacuum flow line and the second (or exhaust) port 32 opens to an exterior surface of the housing 28, such as the bottom surface 56 as best shown in
The check valves 50 and 54 are arranged such that during the intake stroke of the diaphragm 36, air is drawn in through the intake port 30 and during the outflow stroke the air in the expanded chamber is directed to the exhaust port 32. For use as a pressure pump, the check valves may be oppositely arranged.
As above mentioned, the second port 32 opens to an exterior surface of the pump housing, such as the bottom surface 56 as best shown in
The noise mitigation boot 24 has a muffler wall 64 overlying the exterior surface 56 of the housing 28. The muffler wall has formed therein a passage 66 extending from the second port 32 to the backside chamber 40 for effecting fluid communication between the second port and the backside chamber. The passage 66 preferably forms a convoluted path, that may have back and forth sections separated by baffle walls 68 to form a serpentine path. The passage may have a minimum cross-sectional area equal or greater than the cross-sectional area of the second port 32, although smaller cross-sectional areas are possible.
As shown, the passage 66 preferably is formed by a groove 70 in an interior surface of the muffler wall 64 that is in juxtaposition with the exterior surface 56 of the housing. One end of the groove communicates with the second port 32 and the other end communicates with the backside chamber 40. In particular, the groove at one end overlaps the second port and at the other end overlaps the backside chamber opening. Preferably, a plurality of the back and forth sections of the serpentine groove communicate directly with the backside chamber.
Hence, the muffler wall 64 and more generally the noise mitigation boot 24 provides pneumatic communication between the second port 32 and the backside chamber behind the pumping diaphragm. This is shown by the dashed lines in FIGS. 12 and 13. This functions to reduce pneumatic noise. In particular, the exhaust air assists the compression stroke of the pump and is essentially idle during the expansion stroke. The pneumatic communication isolates pneumatic pumping noise with little performance impact. When the pump is used as a pressure pump, the reverse is true with air pulses being substantially cancelled.
The noise mitigation boot 24 preferably is made of an elastomeric material, in particular butyl or chloroprene rubber, that can have a Shore A durometer hardness of between 40 and 80, preferably between 50 and 70, and more preferably between 55 and 65. The muffler wall 64 preferably is pressed flush with the exterior surface such that the exterior surface closes the topside of the serpentine groove.
As best shown in
Generally, the diaphragm pump, with the noise mitigation boot installed, may experience a reduction in flow from 0% to 30%, or from 1% to 20%, or more typically 2% to 10%. The pump may also experience an increase in power consumption from 0% to 30%, or from 1% to 20%, and more typically from 2% to 10%.
The noise mitigation boot 24 preferably has an opening 84 through which the tubular port extension 58 extends. The noise mitigation boot may be sealed around the tubular extension at the opening in the boot.
Although the illustrated boot has other walls in addition to the muffler wall 64 for enabling attachment of the boot to the pump, the boot may consist of only the muffler wall that may be integrated into the pump assembly in any suitable manner.
Although the invention has been shown and described with respect to a certain embodiment or embodiments, it is obvious that equivalent alterations and modifications will occur to others skilled in the art upon the reading and understanding of this specification and the annexed drawings. In particular regard to the various functions performed by the above described elements (components, assemblies, devices, compositions, etc.), the terms (including a reference to a “means”) used to describe such elements are intended to correspond, unless otherwise indicated, to any element which performs the specified function of the described element (i.e., that is functionally equivalent), even though not structurally equivalent to the disclosed structure which performs the function in the herein illustrated exemplary embodiment or embodiments of the invention. In addition, while a particular feature of the invention may have been described above with respect to only one or more of several illustrated embodiments, such feature may be combined with one or more other features of the other embodiments, as may be desired and advantageous for any given or particular application.
This application is a national phase of International Application No. PCT/US2016/030917 filed May 5, 2016 and published in the English language, which claims priority to U.S. Provisional Patent Application No. 62/156,962 filed May 5, 2015, which are hereby incorporation herein by reference.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2016/030917 | 5/5/2016 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2016/179360 | 11/10/2016 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 3877842 | Greene | Apr 1975 | A |
| 4877378 | Saggers | Oct 1989 | A |
| 5232353 | Grant | Aug 1993 | A |
| 5549454 | Earle | Aug 1996 | A |
| 5731556 | Gardner et al. | Mar 1998 | A |
| 6007307 | Sonoda | Dec 1999 | A |
| 6257842 | Kawasaki | Jul 2001 | B1 |
| 6319212 | Müller et al. | Nov 2001 | B1 |
| 6485270 | Wang | Nov 2002 | B2 |
| 6547749 | Hansen | Apr 2003 | B2 |
| 9358562 | Ansley | Jun 2016 | B2 |
| 20020114711 | Wang | Aug 2002 | A1 |
| 20030101959 | Hare | Jun 2003 | A1 |
| 20040123247 | Wachen et al. | Jun 2004 | A1 |
| 20050112004 | Becker | May 2005 | A1 |
| 20060034711 | Bergner | Feb 2006 | A1 |
| 20070160485 | Huang | Jul 2007 | A1 |
| 20130042753 | Becker et al. | Feb 2013 | A1 |
| Number | Date | Country |
|---|---|---|
| 20 2006 006042 | Jun 2006 | DE |
| 1 354 037 | Jun 1974 | GB |
| Entry |
|---|
| International Search Report and Written Opinion for corresponding Patent Application No. PCT/US2016/030917 dated Jul. 6, 2016. |
| Written Opinion for corresponding Patent Application No. PCT/US2016/030917 dated May 23, 2017. |
| Written Opinion for corresponding Patent Application No. PCT/US2016/030917 dated Sep. 21, 2017. |
| Number | Date | Country | |
|---|---|---|---|
| 20180135615 A1 | May 2018 | US |
| Number | Date | Country | |
|---|---|---|---|
| 62156962 | May 2015 | US |
