Reduced energy and volume air pump for a seat cushion
First Claim
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1. A pump system comprising:
- at least one pair of inflatable bladder means within a cushion to support a body having sufficient weight to compress the bladder means;
a reversible pump connected to drive means, the pump comprising a piston within a cylinder, the piston being moved within the cylinder by the drive means and defining a first chamber section within the cylinder on one side of the piston and a second chamber within the cylinder on the other side of the piston;
first fluid conduit means connecting one bladder means of the pair of bladder means to the first chamber section;
second fluid conduit means connecting the other bladder means of the pair of bladder means to the second chamber section; and
two valve means disposed respectively within the first and second chamber sections near the distal end of the travel of the piston within a chamber that open and equalize the pressure across the piston when the piston reaches the valve means.
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Abstract
An efficient pump system for transferring air between sets of bladders in a cushion. The pump system utilizes a reversible piston within a cylinder in conjunction with an equalizing valve in the piston which opens when the piston reaches the end of travel in one direction. The weight of a seated user then forces air back across the piston from an inflated bladder to the previously deflated bladder until the pressure is equalized. In this fashion the work done by the pump is cut in half. The inflation and deflation of the different bladders is controlled to vary the pressure on the several pressure points of a seated user. A principal application is for wheel chair use to prevent pressure ulcers.
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Citations
17 Claims
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1. A pump system comprising:
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at least one pair of inflatable bladder means within a cushion to support a body having sufficient weight to compress the bladder means; a reversible pump connected to drive means, the pump comprising a piston within a cylinder, the piston being moved within the cylinder by the drive means and defining a first chamber section within the cylinder on one side of the piston and a second chamber within the cylinder on the other side of the piston; first fluid conduit means connecting one bladder means of the pair of bladder means to the first chamber section; second fluid conduit means connecting the other bladder means of the pair of bladder means to the second chamber section; and two valve means disposed respectively within the first and second chamber sections near the distal end of the travel of the piston within a chamber that open and equalize the pressure across the piston when the piston reaches the valve means. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A pump system comprising:
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at least one pair of inflatable bladder means within a cushion to support a body having sufficient weight to compress the bladder means; a reversible pump connected to drive means, the pump comprising a piston within a cylinder, the piston being moved within the cylinder by the drive means and defining a first chamber section within the cylinder on one side of the piston and a second chamber within the cylinder on the other side of the piston and guide rod means located within the cylinder such that the piston is pierced by the guide rod means and the interface therebetween is closed by a seal in the piston surrounding the guide rod; first fluid conduit means connecting one bladder means of the pair of bladder means to the first chamber section; second fluid conduit means connecting the other bladder means of the pair of bladder means to the second chamber section; and two valve means disposed respectively within the first and second chamber sections near the distal end of the travel of the piston within a chamber that open and equalize the pressure across the piston when the piston reaches the valve means comprising portions of reduced cross sectional area of the guide rod means. - View Dependent Claims (12, 13, 14, 15, 16, 17)
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Specification