Pumps – Expansible chamber type
Patent
1994-07-12
1995-12-05
Bertsch, Richard A.
Pumps
Expansible chamber type
604 9, F04B 4302
Patent
active
054723256
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The present invention relates to a suction pump for draining body fluids from body cavities, the suction pump comprising a bottom portion and a domed resilient pump body having a substantially smooth inner surface, the pump body being connected to the bottom portion along its rim and forming a pumping chamber between the bottom portion and pump body, which suction pump further comprises an inlet valve and an outlet valve, the resilient pump body being resiliently deformable by manual action from its domed configuration towards the bottom portion for the provision of the pressure stroke of the suction pump and due to its elasticity returning to its domed configuration when relieved for the provision of the suction stroke of the pump.
A pump of the type mentioned above is disclosed in EP patent application No. 87307362.1 (publication No. 0270205). The domed pump body of the noted pump has a flat top which may be supported along its inner surface by means of two sets of intersecting ridges and the bottom portion is flat and may be provided with a set of upwardly extending ridges. In its deformed state the bottom and the inner surface of the pump body are spaced, and hence the pump has a large pump clearance volume, which means that only a relatively small part of the pump chamber is used in the pumping operation. The prior art pump is implantable and serves to transport body fluid from one cavity of the body into another when activated. Furthermore, the ridges of the pump body, if provided, serve to quickly return the pump body to its starting position. Similar pumps having an internally smooth domed pump body and a flat bottom portion are disclosed in GB 1,146,413 and GB 1,173,071.
SUMMARY OF THE INVENTION
It is the object of the present invention to provide a pump of the above-mentioned type in which the pump chamber is utilized so efficiently that the pump obtains a large capacity in relation to its size and which allows the suction pressure produced by the pump to be maintained for relatively long periods between consecutive pressure strokes, the object being obtained according to the invention by the bottom portion having a concave portion which substantially corresponds to the inner configuration of the pump body in the deformed state thereof. As a result, it is possible to manually place at least the major part of the inner surface of the pump body in the deformed position thereof close to or in contact with the concave part of the bottom portion, thereby forming a very small clearance volume in the pump, and consequently it is possible to use approximately the entire volume of the pump chamber for the pumping function, thereby allowing the suction pressure to be maintained for relatively long periods.
In tests forming the basis of the present invention it was found that if the inner surface of the pump body according to a preferred embodiment of the invention in the domed state of the pump body substantially has the form of a spherical segment, the suction pressure produced by the pump will only vary relatively little during the suction stroke, i.e., in the period during which the pump body returns from its deformed state to its domed configuration.
In a preferred embodiment of the pump according to the invention the spherical segment has an arc measure ranging between about 100.degree. and 140.degree., expediently between 110.degree. and 130.degree., and preferably being about 120.degree..
A further embodiment of the pump according to the invention is characterized in that at its top the spherical segment has a slightly smaller radius of curvature than at its sides. This embodiment has been found to provide a satisfactory equalization of the variations in pressure which may occur during the suction stroke.
According to a still further embodiment of the pump of the invention the inlet valve and the outlet valve are offset in relation to the rim of the pump body and connected to the pump chamber through channels in the concave portion of the bottom portion. This results
REFERENCES:
patent: 3111125 (1963-11-01), Schulte
patent: 3127846 (1964-04-01), Kerns
patent: 3496872 (1970-02-01), Riester
patent: 3588293 (1971-06-01), Morales
patent: 3947156 (1976-03-01), Becker
patent: 4290346 (1981-09-01), Bujaw
patent: 4479761 (1984-10-01), Bilstad et al.
patent: 4634430 (1987-01-01), Polaschegg
patent: 4657490 (1987-07-01), Abbott
patent: 4850955 (1989-07-01), Newkirk
patent: 5002471 (1991-03-01), Perlov
patent: 5152753 (1992-10-01), Laguette
Bertsch Richard A.
Korytnyk Peter G.
Uno Plast A/S
LandOfFree
Suction pump for draining body fluids from body cavities does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Suction pump for draining body fluids from body cavities, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Suction pump for draining body fluids from body cavities will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1369832