Pumps – Motor driven – Electric or magnetic motor
Reexamination Certificate
1998-04-03
2001-07-10
Freay, Charles G. (Department: 3746)
Pumps
Motor driven
Electric or magnetic motor
C604S074000, C251S208000, C092S099000, C092S140000
Reexamination Certificate
active
06257847
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to motorized pumps, and more particularly, to breastpumps.
Breastpumps are convenient for nursing mothers, because, among other things, they allow the nursing mother to draw off breast milk to feed to the child at a later time when the mother may not be present. For some mothers, breastpumps are required, particularly when the child has suckling difficulties, or if the mother has problems with excessive or deficient milk production, or cannot empty completely. Some mothers also require breastpumps in the event of soreness or injury of the manilla, or sunken manilla.
Manually-driven breastpumps are commonplace. However, they typically require the use of both hands to pump a single breast—one to hold the breast shield/pump in place, and the other to drive the pump. There are also manually driven breastpumps that can be operated with one hand, as by using a lever-type drive mechanism. They also obviously require some manual effort to operate.
Motor-driven pumps for breastpumps, such as battery-powered or house-current powered, also have been marketed. While eliminating the need for manually reciprocating the pumping mechanism, those pumps made for operating two breast shield assemblies at once—double-pumping—have typically been quite large, and often quite heavy. Smaller battery-powered pumps which are part of the breast shield assembly itself have not historically been adapted to, or capable of, double-pumping off the same pump.
SUMMARY OF THE INVENTION
The present invention was designed with many of the foregoing considerations in mind. It has a principal objective to provide a relatively inexpensive but efficient pump that is readily portable because it is compact and lightweight.
The motor drive mechanism of the pump has a durable drive train, and the main vacuum-generating pump components—flexible diaphragm and rigid cap—are each preferably detachably mounted together within a frame. Assembly, and disassembly—as for repair or cleaning—are therefore efficiently and easily accomplished. A pressure regulator valve mechanism on the rigid cap further provides simple manual control for varying negative pressure developed by the pump.
These features make the inventive pump ideally suited for a breastpump. More particularly, the present invention in one form is an electrically-powered diaphragm pump mounted within a support frame contained in a soft carrying case. A zippered flap in the carrying case provides access to the front of the pump unit, which has spigots for attaching tubing that connects to breast shield assemblies.
The diaphragm pump in one form of the invention has a durable drive chain comprising a drive shaft fit with an eccentric cam, to which is attached a follower. The follower is in turn pivotably connected to a puller that is attached to a flexible diaphragm. The diaphragm rests near or against the interior surface of a rigid cap, the latter being stationarily mounted. An expansible chamber is thus provided. In operation, the rotation of the drive shaft rotates the cam, causing the follower to move back and forth as it orbits the shaft. The puller moves with the follower, drawing the diaphragm away from the cap and forming a negative pressure that is communicated by one or two spigots to tubing attached to the breast shield assemblies.
It is also contemplated that the foregoing drive mechanism be adapted to drive two diaphragms in respective cap assemblies. In one such an embodiment, the puller would take the form of a yoke to which the diaphragms are connected. The follower would then reciprocate to move the puller and associated diaphragms toward and away from the caps. In another such embodiment, a pair of opposed pullers would be used in a push-pull arrangement, whereby the two pumps cycle oppositely. Of course, this diaphragm and cap assembly is but one type of expansible chamber pump that could be advantageously used with other aspects of the invention.
The pump further can include a vacuum regulator device on the cap. The regulator device can also be located elsewhere, such as anywhere between the breast shield and the vacuum source, or on the breast shield itself. In one embodiment, the vacuum regulator comprises a rotary valve member mounted for rotational movement on the rigid cap. An aperture is formed through the valve member. At least one hole or recess is formed through the cap member, and communicates with the pressure region generated between the cap interior and the diaphragm.
The valve member has a first position wherein the valve aperture and the cap hole are aligned to place the pressure region in communication with atmosphere, and a covered position wherein the valve aperture and the cap hole are unaligned, with the valve member thereby closing the cap hole. A maximum and minimum vacuum level are thereby provided, depending on whether air can be drawn within the cap or not, as controlled by the valve.
A second hole different in size from the first cap hole can be additionally provided, establishing a second position wherein the valve aperture and the second cap hole are aligned for a different vacuum level. Maximum, medium and minimum vacuum levels can thus be made available through adjustment of the cap hole sizes.
The foregoing vacuum regulator device has further been modified in another embodiment. In the latter form, the rotary valve member has a crescent-shaped channel formed in its base (the part that is in contact with the cap). The aperture through the valve member extends into this channel. Two cap holes are formed in the cap. In the minimum vacuum position, the channel overlies both cap holes; in the medium position, only one hole, and in the maximum vacuum position, neither cap hole is in communication with the channel.
In yet another embodiment, the vacuum regulator device takes the form of a ring element which is rotatably mounted on each of a pair of caps in a pump adapted for double breast pumping. The rotatable element is easily manipulated. This also enables independent control of the vacuum being generated in each breast shield assembly, for maximum convenience of the mother. The previously noted vacuum regulator devices above can likewise be used on each of the pump caps for the same advantageous independent control. Also, a continuously variable vacuum regulator device has been developed and can be used.
In a further evolution and adaptation of the foregoing invention utilizing a diaphragm pump, an apparatus has been developed which is particularly adapted for double breast pumping (although, and as will be seen, single breast pumping is also plainly included within its ambit).
In a first form of this adaptation, a double-diaphragm pumping mechanism has a pair of opposed pressure-generating units, in particular for generating a negative (vacuum) pressure. In a presently contemplated embodiment, one unit is adapted for direct attachment to a breast shield assembly. This unit has a diaphragm mechanism which is inserted into a receptacle, or collar, formed as part of the breast shield assembly. With the collar, the diaphragm forms a chamber within which a vacuum is generated. The other unit in this embodiment is self-contained, i.e., it has a diaphragm mechanism located within a rigid cover to form another (second) chamber within which a vacuum is generated. An outlet port is provided for communicating the vacuum this second chamber is generating. That outlet port is connected by tubing to another breast shield assembly.
A common drive mechanism serves to operate both of the pressure chambers of this double-diaphragm pump. In the foregoing embodiment, the drive mechanism uses an offset push-pull arrangement to create alternating negative pressure in the respective chambers. This results in alternating suction on the breasts. The double-diaphragm pumping mechanism of this embodiment (which is mounted to a breast shield assembly) is compact and light enough to be readily supported on a single hand-held breast shield assembly, such that it can be held in place by the mother on o
Annis Larry D.
Silver Brian H.
Baniak Pine & Gannon
Freay Charles G.
Medela, Inc.
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