Breast pumps are well known, but the field of breast pump devices with self-contained breast milk reservoirs which can be used discreetly by fitting them within a woman's brassiere, often under ordinary clothing so that a woman can use a breast pump around others discreetly, is relatively new. The only known devices in this field, upon which this invention improves, are taught in U.S. Pat. Nos. 7,559,915 and 8,118,772 (Dao, Garbez), and U.S. Pat. No. 8,702,646 (Dao, Garbez, Paul, Sutton), all commonly assigned, the disclosures of which patents are incorporated by reference herein.
To provide adequate milk collection capacity for lactating women using a breast pump, some presently available breast milk reservoir devices are large, and when placed in a brassiere give a lactating woman an enhanced appearance. These breast milk collection devices are frequently used by a lactating woman underneath her clothing and in the presence of others. An embodiment of these devices utilizes a flap valve between the vacuum source and the stored milk, and the devices reach their maximum collection capacity once the collected milk in the reservoir reaches the bottom of the flap valve.
The risk from overfilling above the level of the flap valve is that when the pump is turned off, the valve may not prevent the undesirable backflow of milk into the breast funnel. This constraint leaves possibly more than half the potential volume of the reservoir unused.
U.S. Pat. No. 8,118,772 discloses in an embodiment a breast milk collection device that includes a flexible barrier between the source of suction force and the milk collected in the reservoir. In this device, the milk in the reservoir can migrate from the reservoir into the interior of the flexible barrier when the vacuum source tube is removed and the collection device is inverted to pour collected milk out of the reservoir into a suitable storage container. The interior of the balloon-shaped flexible barrier of the '772 patent would be practically difficult to clean after each use. To prevent milk from entering the flexible barrier of the '772 patent, the funnel-shaped adapter would have to be detached from the reservoir housing before removing the milk from the reservoir, leading to potential undesirable splashing of the milk. Further, in the milk collection device of the '772 disclosure, the vacuum force tube has to be removed from the breast milk collection device for milk to be transferred out of the reservoir.