Abstract:
A device for protecting the diaphragm of a pump, such as a diaphragm pump for a breastpump, from fluid (air/milk) is disclosed. A mounted flexible cover is located between the shell of the pump and the movable diaphragm membrane within the shell which isolates the membrane from fluid.

Description:
RELATED PATENT APPLICATIONS 
     This application is a continuation-in-part of Ser. No. 10/413,463, filed Apr. 14, 2003, which is a continuation-in-part of both U.S. patent application Ser. No. 09/475,681, filed Dec. 30, 1999 (now U.S. Pat. No. 6,547,756), and U.S. patent application Ser. No. 10/114,686, filed Apr. 2, 2002 (now U.S. Pat. No. 6,808,517), which is a continuation-in-part of U.S. patent application Ser. No. 09/476,076, filed Dec. 30, 1999 (now abandoned), all of which claim the benefit of U.S. Provisional Application No. 60/170,070, filed Dec. 10, 1999. 
     This application is also a continuation-in-part of U.S. patent application Ser. No. 09/591,749 filed Jun. 12, 2000 (now U.S. Pat. No. 7,255,681), which is a divisional of U.S. patent application Ser. No. 09/055,101 filed Apr. 3, 1998 (now U.S. Pat. No. 6,257,847), which is a continuation-in-part of U.S. patent application Ser. No. 08/510,714 filed Aug. 3, 1995 (now U.S. Pat. No. 5,776,098). 
    
    
     FIELD OF THE INVENTION 
     This invention relates to breastpumps for drawing breastmilk, and particularly to a motorized, such as electrically driven, breastpump. 
     BACKGROUND 
     Breastpumps for use by nursing mothers are well known. They allow the nursing woman to express the breastmilk as necessary or convenient, and further provide collection of the breastmilk for later use. For some mothers, breastpumps may be a necessity, such as when the child has suckling problems, or if the mother has problems with excessive or deficient milk production, or soreness, deformation or injury of the mammilla. 
     Manual breastpumps are commonplace, primarily because they are relatively inexpensive and easy to transport. Being manually driven, however, stroke rate and suction pressure produced can be uneven, and operating the pump can ultimately be tiring. 
     Electrically-driven breastpumps are also commonplace. They may be of a substantially large size of a non-portable or semi-portable type, typically including a vacuum pump which has an electric motor that plugs into standard house current. Advantages of this type of pump are ready controllability and regulation of the vacuum, and the ability to pump both breasts at once. That is, the nursing woman has both hands free to hold two breastpump shields in place for pumping of both breasts at the same time. 
     Battery-driven breastpumps have also been developed. These breastpumps have the advantages of controllability and regulation of the vacuum, as well as being easily carried. Such a battery-driven portable breastpump is described in U.S. Pat. No. 4,964,851, for example. This breastpump, sold under the name MINIELECTRIC by Medela, Inc., is lightweight and achieves good vacuum (i.e., negative pressure) regulation in preferred limits, for example, between about 100 and about 220 mmHg. The LACTINA breastpump sold by Medela, Inc. is also another type of breast pump which may be driven by battery as well as house current. It is generally disclosed in U.S. Pat. No. 5,007,899. 
     Breastpumps, such as the foregoing motorized pumps, typically have internal workings that should be isolated from milk and other fluids and material. This is particularly true where such pumps may be used by many women, such as in hospital or rental settings. 
     SUMMARY 
     One aspect of the present invention is a breastpump assembly having a prophylactic device for protecting the diaphragm from fluid (air/milk). In one embodiment of this aspect of the invention, a diaphragm pump for a breastpump comprises a shell having a generally hemispherical interior shape with a flexible membrane movable within the hemispherical shape to expand and contract a volume created in a chamber defined between the membrane and the shell. A mechanism connected to the membrane, such as a puller, moves the membrane to expand and contract the volume. A port is provided in the shell through which air moves in response to expansion and contraction of the volume, such that vacuum can be communicated to a breastshield through connection to the port. 
     A mounted flexible cover is located between the shell and the membrane which isolates the membrane from fluid. The membrane has a circumferential rim upon which the cover is received over the rim. The shell has an internal opening defined therein sized to encompass the rim with the cover mounted on the rim in a substantially airtight fit. The flexible cover thereby forms a gasket between the rim and shell. A one-way valve extending through the membrane is additionally provided, allowing exhaustion of air between the membrane and cover. 
     The protective cover may be made removable and/or disposable. The protective cover may also be made as a more or less permanent element of the breastpump assembly, in that it is not expressly removable or disposable, but is still cleanable in situ nevertheless. 
     These as well as other aspects and advantages will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference where appropriate to the accompanying drawings. Further, it is understood that this summary is merely an example and is not intended to limit the scope of the invention as claimed. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Certain examples are described below in conjunction with the included figures, wherein like reference numerals refer to like elements in the various figures, and wherein: 
         FIG. 1  is a front perspective view of a breastpump assembly made in accordance with aspects of the present invention; 
         FIG. 2  is a top view of the breastpump of  FIG. 1  with a cover removed revealing diaphragm pumps; 
         FIG. 3  is a somewhat exploded assembly view of the major components of the breastpump of  FIGS. 1 through 2 , with a modified top cover for the diaphragm pump assembly; 
         FIG. 4  is a front perspective view of another embodiment of a breastpump assembly made in accordance with aspects of the invention; 
         FIG. 5  is a somewhat exploded assembly view of the major components of yet another breastpump made in accordance with the present invention; 
         FIG. 6  is an enlarged assembly view of the diaphragm pump mechanism; 
         FIG. 7(   a ) is a cross-sectional view of the assembled diaphragm pump of  FIG. 5 ; 
         FIG. 7(   b ) is an elevational view of the assembled diaphragm pump of  FIG. 5 ; 
         FIG. 7(   c ) is a top view of the assembled diaphragm pump of  FIG. 5 ; 
         FIG. 8  is a sectional view of the assembled breastpump of  FIG. 4  taken through the middle of the breastpump along its long lateral axis (side to side) looking rearwardly; 
         FIG. 9  is a cross-sectional view of yet another embodiment of a breastpump assembly made in accordance with aspects of the invention; and 
         FIG. 10  is an exploded perspective view of several elements of the diaphragm pump of the assembly of  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1 through 3  initially, a breastpump assembly of the present invention in one form has a casing  10  with a drive unit  25  mounted therein. There are, of course, any number of drives that may be used for diaphragm pumps such as those used in the instant embodiment. Indeed, the type of drive unit is not necessarily significant to certain aspects of the present invention. The drive unit  25  generates a linear movement (push and pull) that drives a pair of diaphragm pumps  30 . 
     The drive unit  25  engages the diaphragm pumps  30  through mechanical coupling with the interior of a respective diaphragm membrane member  34 . The linear pulling motion of the drive unit causes a negative pressure, or vacuum, to be generated in the pair of diaphragm pumps  30 . Each diaphragm pump has a flexible membrane  34  mounted in the upper housing  11  assembled with a respective rigid shell  24  (and see  FIGS. 6 and 7(   a ) through  7 ( c ) described further below). The membrane  34  and shell  24  are in substantially airtight engagement. When the membrane  34  is pulled away from the shell  24 , a vacuum is generated in the space between the shell interior and the membrane, which can be accessed through outlet port  31  formed on the shell, to which a tube  32  is connected to communicate the vacuum to a respective breastshield  17 . 
     It will be noted that the  FIG. 4  embodiment is substantially the same as that of  FIGS. 1 through 3 , except for a modified cover for the upper housing. In the embodiment of  FIG. 4 , the rigid shells  24  for the diaphragms are formed as part of the cover  35 . In all other respects, the functionality of the diaphragm pump of  FIG. 1 through 3  is substantially similar to the embodiment of  FIG. 4 , as further described below. 
       FIG. 4  shows another version of a breastpump of the present invention substantially the same as that of  FIGS. 1 through 3 , except with a modified cover  35 ″ and shell  24 ′ (primed numbers being substantially similar to their un-primed counterparts) for the diaphragm pump  30 . In one embodiment, the two diaphragm pumps  30  are in a well formed in the top of the casing  10 . A cover  35  (also  35 ′ and  35 ″) is provided which fits over the well and is generally flush with the upper housing part  11 . The outlets  31  extend through relieved areas in the cover  35 , for example, for easy access in use. 
     As noted above, in the embodiment of  FIG. 3  the shells  24  are shown formed in the cover  35 . The embodiment of  FIG. 5  has the shells  24  mounted in the upper housing, as through a snap fit or interference engagement, such as shown in the embodiment of  FIGS. 6 and 7(   a ) through  7 ( c ), to allow easier access for cleaning or replacing the membranes of the pumping mechanism, and for cleaning the shells themselves (which are provided with grips  33  to these ends). 
     In the embodiment of  FIG. 5 , diaphragm member or membrane  34 , which may be made of any suitably durable flexible and durable fluid-impervious material (to be airtight), such as silicone with a Shore A hardness in the range of 30 to 70, is molded around its perimeter to a rigid plastic collar  85 . Collar  85  has a plurality of depending anchor posts  86  with outboard flanges formed thereon, which engage with the inside lip of the respective well in the upper housing part  11  within which the collar  85  is received to snap-fit the membrane  34  in place. 
     In addition, prophylactic (protective) covers  36  may be advantageously provided, which form-fit over the diaphragms  34  and isolate them from air and other fluid from the breastshields. The covers  36 , which can be made of the same material as the membranes, are likewise fluid-impervious. 
     Referring to  FIGS. 6 and 7(   a ) through  7 ( c ) in particular, each of the covers  36  has an upturned cuff  87  which forms an annular well around the perimeter of the cover  36 . A pair of circumferential beads  88  and  89 , which are slightly offset vertically from each other, are formed along the bottom area of the annular well. Uppermost bead  88  engages in an annular rim channel  90  formed along the bottom outside of shell  24 ′, for a substantially airtight engagement between the protective cover  36  and the shell. 
     An interior channel  93  is formed within the interior bottom of the cover  36  by a bead  91  and shoulder  92 , which each run circumferentially around the cover. This interior channel  93  is received on a slightly protruding edge or rim on the collar  85  of the membrane  34 . An airtight fit is thus provided between the protective cover  36  and the membrane  34 , which also serves to fix the shell  24  in place over the membrane  34 , and complete the diaphragm pump  30 . 
     Note also that a one-way valve  95  is provided in the membrane  34 , which communicates with the possible space that may form between the membrane  34  and overlying cover  36 . This valve permits any entrapped air between the membrane  34  and the overlying cover  36  to be exhausted, such as if the first stroke on start-up happens to be toward the shell  24 , with the protective cover  36  thereafter then following the movement of the diaphragm  34  to which it will generally be in facial engagement. 
     Referring to  FIGS. 9 and 10 , yet another embodiment of a diaphragm pump assembly is illustrated. In this embodiment, diaphragm  170  is mounted to the front plate  124  of the assembly using a diaphragm mounting ring  174 . Diaphragm  170  has a perimetrical shoulder  176  formed thereon from which depend inner and outer concentric circular flanges  178  and  180 , respectively. Overlying the diaphragm  170  is a rigid housing cap  186  made of polypropylene. Cap  186  has an inner surface roughly matching the curvature of the diaphragm  170 , such that the diaphragm rests close to or against the interior surface of the cap  186 . 
     A thin disposable membrane-like cover (not shown) may additionally be provided over the diaphragm  170 . This disposable cover would be between the diaphragm  170  and inside of the cap  186 , and serve to further hygienically isolate the diaphragm  170  from any milk, air or the like which could be pulled within the cap  186  in the vacuum stroke. This disposable cover would be particularly useful if there were multiple users of the pump. The protective cover may, of course, be made non-removable. It would then be cleanable in situ, while still providing the desired isolation of the membrane and other inner workings of the pumping mechanism. 
     Further details of the foregoing embodiments may be gleaned from U.S. Pat. Nos. 5,776,098 and 6,547,756, the disclosures of which are hereby incorporated in herein in their entirety, as if specifically set forth in this application. In that regard, it should be noted that the numbered elements in  FIGS. 9 and 10  that are not specifically addressed in this text are the same elements described in the foregoing U.S. Pat. No. 5,776,098 with a leading “1” added thereto (e.g., element  112  herein is element  12  therein). 
     While the invention has been described herein with relation to certain embodiments and applications, those with skill in this art will recognize changes, modifications, alterations and the like which still come within the spirit of the inventive concept, and such are intended to be included within the scope of the invention as expressed in the following claims. It is to be understood that no limitation with respect to the specific methods or processes illustrated herein is intended or should be inferred. In addition, it is to be understood that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements may be subsequently made by those skilled in the art, which are intended to be encompassed by the following claims and those equivalents to which they are entitled.