US 3587568 A
Description (OCR text may contain errors)
United States Patent lnventor Eugene P. Thomas Baltimore, Md.
Appl. No. 488,430
Filed Sept. 20, 1965 Patented June 28, 1971 Assignee Westinghouse Electric Corporation Pittsburgh, Pa.
INFLATABLE MATTRESS APPARATUS 16 Claims, 5 Drawing Figs.
U.S. Cl 128/33 Int. Cl A6lh 1/00 Field ofSearch 128/24, 33,
 References Cited UNITED STATES PATENTS 3,390,674 7/1968 Jones 128/33 2,460,245 1/1949 Summerville 128/33 2,684,672 7/1954 Summerville 128/33 3,098,504 7/1963 .loesting l37/624.l4 3,185,166 5/1965 Horton 137/815 3,282,280 11/1966 Horton 137/815 Primary ExaminerL. W. Trapp Attorneys-F. H. Henson, Klipfel E. P. and D. F. Straitiff ABSTRACT: An inflatable mattress apparatus wherein different cells are alternately inflated and deflated in out-ofphase relationship under control of a pure fluid selector valve device.
INFLATABLE MATTRESS APPARATUS Such apparatus as heretofore provided, particularly with respect to the inflation control means embodied therein, has been characterized by a'relatively high degree of complexity and noise which can be disturbing to the invalid using such apparatus. It therefore becomes a prime object of the present invention to provide an improved inflatable mattress apparatus. It therefore becomes a prime object of the present invention to provide an improved inflatable mattress apparatus including an inflation control means therefor which is relatively simple and quiet in operation.
Other objects, features and advantages of the invention will become apparent from the following detailed description of illustrative embodiments thereof, when taken in connection with the accompanying drawings, in which:
FIG. 1' is an isometric view of a bed employing an inflatable mattress apparatus constructed in accord with the present invention;
FIG. 2 is a side view, partly in outline and partly in section, of an embodiment of a pure fluid switching device including silencing means therefor included in the apparatus of FIG. 1;
FIG. 3 is a cross-sectional plan view taken along the line III-III in FIG. 2;
FIG. 4 is an alternate construction of a pure fluid selector valve device which may be substituted for that shown in FIGS. 2 and 3; and
FIG. 5 illustrates or exemplifies a construction wherein both the pure fluid selector valve device as well as an air compressor are arranged to share a common silencing enclosure.
Referring to FIG. I, the apparatus embodying the invention comprises an inflatable mattress 9 having two sets 10 and II of inflatable cells l2 formed between sheets of plastic material such as vinyl, by virtue of a sinuous bond 8 which affords interleaving of the two sets 10 and 11 of cells 12 which, as shown, extend longitudinally along the inflatable mattress. Such inflatable mattress 9 in turn is placed on top of a conventional mattress 14 of a bed 15 and serves as a top pad therefor. By alternate supply and release of fluid under pressure to the two sets of cells 10 and 11 in out-of-phase relationship, support of an invalid on such mattress or pad is varied, in well known manner, such as to prevent bed sores from developing.
In accord with a feature of the present invention, a simplified inflation control means in the form of a pure fluid selector valve device 17 or pneumatic switching device is provided in the form of a thin rectangular wafer construction which can be supported, as shown in FIG. 1 in a pocket 18 formed in an apron 19 affiliated with the mattress or pad 9 at the foot of the bed 15. Such pure fluid selector valve device 17 requires simply three hose connections thereof, an air supply hose 22, and two output air conveying hoses 23 and 24 connected to the two sets of cells 10 and II in the mattress or pad 9. Such pure fluid selector valve device 17 employs no moving parts and is capable of alternately effecting pressurization and depressurization of the two sets of cells 10 and 11 in out-ofphase relationship. In the case of hospital rooms having wall outlets 26 for compressed air, as shown in FIG. 1, the air supply hose 22 need merely be connected to such wall outlet through the medium of a pressure regulator value device 28 which assures that the air pressure furnished to the inflatable mattress or pad 9 is not excessive. In accord with a feature of the invention, sounds created by air rushing through the plastic hose or tubing as well as through the pure fluid selector valve device is muffled or quieted in a manner described hereinafter.
Referring to FIGS. 2 and 3, 'a form of pure fluid selector valve device I7, sometimes referred to as pure fluid amplifier, which has been suitably employed may take the form of one as shown in FIGS. 2 and 3 in which such device is constructed substantially of a thin rectangular member 30 of glass, or other material in which is etched or otherwise formed an input duct or channel 31 having an input or power nozzle 32 formed at one end and directed into a splitter chamber 33 from which diverge in a direction away from the input nozzle two exit or output ducts or channels 36 and 37 at the opposite sides of a splitter vane 38. Such member 30 also has formed therein two oppositely arranged control nozzles 40 and 42 for diverting the jet of air emanating from the input nozzle 32 to one or-the other of the exit of output channels 36 and 37. In. the construction shown in FIGS. 2 and 3, the control nozzles 40 and 42 may simply be open to the exterior of the device, and hence to the atmosphere, without any feedback connection from either of the output channels 36 and 37 and yet obtain automatic alternation of jet switching from one of such output channels to the other as a reaction to the output pressure conditions imposed on such channels by the two sets of mattress cells 10 and 11. In the construction of the pure fluid selector valve device 17 of FIGS. 2 and 3, the input nozzle 32 will create a jet of air from the supply air conveying means which will travel through the splitter chamber 33 to such as the right-hand output channel 37, thence to one set 10 of mattress cells 12 by way of the respective outlet air conveying means 24 as indicated by the solid arrows, while at the same time exiting such output channel 37 also by way of a vent port means 45 open thereto. When the pressure of air in the mattress cells receiving such air from the right-hand output channel 37 reaches a value of such as one-half of the supply air pressure the device 17 will automatically switch the jet of air to the lefthand output channel 36 which jet will then travel to the set of mattress cells I! as well as to some extent to the atmosphere by way of the left-hand vent port means 46. At the same time that the jet of air is diverted to the left-hand output channel 36, air in the mattress cells 10 connected to the right-hand output channel 37 will vent to the atmosphere by way of such output channel and the respective vent port means 45. The control nozzle means 40 and 42 affiliated with the splitter chamber 33 apparently functions as a result of aspiration by the jet passing thereby, and assist the automatic switching of the supply stream of air. Otherwise, such automatic operation, without pressure feedback from the output channels 36 and 37 to the control ports 40 and 42 might find explanation in the literature on the basis of blocking of one and the other of the two output channels 36 and 37, which in effect takes place once the pressure in a given mattress cell set has obtained a certain value and is incapable 'of accepting any further pressurization at a given supply pressure. A diagram illustrating the effect of blocking is shown, for example, in an article appearing in the Scientific American, Dec. 1964 issue.
An alternate construction of a suitable pure fluid selector valve device 17, or so-called pure fluid amplifier, is shown in FIG. 4. In this configuration the vent port means 45 and 46 affiliated with the output channels 36 and 37, are open to the atmosphere at right angles to the direction of extension of the output channels, and the control nozzles 40 and 42 are provided with restricted control channels 50 and 51 having feedback connections from the output channels, respectively. Upon obtaining of a certain pressure condition in a respective output channel 36 or 37, the respective control nozzle 40 or 42 will develop a control jet sufficient to deflect the air supply jet from one side to the other of the splitter vane 33.
In accord with other features of the invention, the flow of air through and out of the pure fluid selector valve device 17 tends to produce an audible noise, and accordingly such device is placed within an enclosure 53 into the interior of which the vent port means 45 and 46 of such device 17 empties. One wall 54 of the enclosure is provided with a plurality of exhaust ports 55, and exhaust air quieting means 56 is disposed within such enclosure to render the air from the vent port means 45 and 46 silent in leaving the exhaust port means 55 of the enclosure 53 in reaching the atmosphere. Such exhaust air silencing means 56, in the embodiment illustrated in FIGS. 2 and 3 comprises layers of wire or plastic screen 57 interleaved with layers of felt cloth 58 and a perforated plate 59 of rigid material, all overlying the exhaust ports 55 in the one wall of the enclosure 53.
In accord with other features of the illustrative embodiment of the invention as shown in FIGS. 2 and 3, the pure fluid selector valve device 17 includes respective nipples 62 attached to such device and open to the input duct 31 and the two output channels 36 and 37. The interior dimensions of the enclosure 53 are such that the pure fluid selector valve device 17, including its three nipples 62, can be inserted thereinto with the wall 54 removed. Such device 17 is retained in place and its input and output'channels acquired of accessibility to the exterior of such enclosure by way of respective insertable nozzle extension members 64 which are in air tight engagement with the walls of respective openings 65 in such enclosure; the innermost end of each such nipple extension member 64 being adapted for insertable connection to the exterior of the respective nozzle 62 attached to the pure fluid selector valve device 17. When assembled, the nipple extension members 64 then accommodate connection to flexible hoses or tubing 22, 23 and 24 forming part of the supply air and outlet air conveying means.
Further, in accord with an additional feature of the invention, the two outletair conveying means 23 and 24 defining the supply-exhaust communications between the pure fluid selector valve device 17 and the two mattress cell sets and 11 are provided with an air flow silencing means 67 which, in the illustrative embodiment set forth herein simply takes the form of a piece of string or yarn, FIG. 3. Such silencing string or yarn element preferably extends from the exit end of at least the respective nipple extension members 64 affiliated with the enclosure 53 for the pure fluid selector valve device 17, through the tubing hoses 23 and 24, to and perhaps including a part of the inflatable mattress itself. This arrangement assures that even though the invalid may have his ear resting against or extremely near to the mattress or pad, no disturbing air flow sounds will be heard.
In accord with a further alternate feature of the invention, where a separate air supply may be, necessary for operation of the inflatable mattress or pad, as in the home or in hospitals where no wall air supply is available, the invention contemplates, as illustrated schematically in FIG. 5, inclusion of an electrically-operated compressor assemblage 70 which is shock and vibration mounted, as by suspension springs 71 within an enclosure or housing 73 in common with the pure fluid selector valve device 17. The bottom of the housing 73 is provided with the exhaust ports 55, and the exhaust-air-silencing sandwich assemblage 56 is shown affiliated with such exhaust ports.
While illustrative embodiments of the invention have been described with a certain degree of particularity, it will be understood that the true spirit and scope of the invention is intended to be covered by the appended claims.
1. An inflatable mattress apparatus comprising at least two separately-pressurizable sets of inflatable mattress cells, the cells of one set being interposed with the cells of the other set for distributed variable support of an invalid during out-ofphase pressure variations created in said cell sets; two outlet air conveying means defining supply-exhaust communications between the two sets of mattress cells, respectively; supply air conveying means; and a pure fluid selector valve device having at least an input nozzle open to such supply air conveying means, two output channels in pneumatic communication with the two outlet air conveying means, two control nozzles affiliated with the input jet nozzle, and vent port means open to such output channels; said pure fluid selector valve device being operable to create a jet of air from such input nozzle and to periodically switch such jet from one output channel to the other responsively to pressure conditions established in the mattress cell sets, whereby, alternately, such jet of air flows to one mattresscell set to preponderantly pressurize same via a respective output channel while air flows from the other mattress cell set via the other output channel and the vent port means to decrease pressurization of same.
2. The inflatable mattress apparatus of claim 1, furthercomprising air flow silencing means for quieting exhaust air exiting the vent port means of the pure fluid selector valve device.
3. The inflatable mattress apparatus of claim 2, wherein the air flow silencing means comprises an enclosure in surround of the pure fluid selector valve device into the interior of which the vent port means thereof empties, which enclosure has exhaust ports opening its interior to the atmosphere, and antiturbulence flow-distributing means disposed in said enclosure in affiliation with such exhaust ports.
4. The inflatable mattress apparatus of claim 3, wherein'said antiturbulence flow-distributing means is in the form of a layered array of felt, screen, and perforated plate disposed over the exhaust ports of the enclosure.
5. The inflatable mattress apparatus of claim 3, wherein said inlet air conveying means and outlet air conveying means each comprises a nipple attached to the pure fluid selector valve device and a nipple extension projecting therefrom outwardly of the enclosure through a respective opening therein, each such nipple, nipple extension and enclosure opening being so constructed and arranged as to permit slidable insertion of the nipple extension member through the respective enclosure opening for airtight attachment with the respective nipple.
6. The inflatable mattress apparatus of claim 3, wherein the enclosure in surround of the pure fluid selector valve device also contains an air compressor acting as the source of compressed air for operation of such apparatus.
7. The inflatable mattress apparatus of claim 1, wherein air flow silencing means are affiliated with the outlet air conveying means.
8. The inflatable mattress apparatus of claim 7, wherein said outlet air conveying means includes flexible plastic tubing and said air flow silencing means with respect to said tubing is in the form of at least one multistranded stringlike element extending through such tubing.
9. The inflatable mattress apparatus of claim 1, further comprising a pressure regulator valve device included in said supply air conveying means.
.10. The inflatable mattress apparatus of claim 1, wherein said pure fluid selector valve device is disposed adjacent to said inflatable mattress cells and said supply air conveying means includes an air supply hose extending from said pure fluid selector valve device and a pressure regulating v'alve device at a remote end of said hose adapted for connection to a compressed air wall outlet.
11. An inflatable mattress or the like and control therefor comprising a mattress having at least a first group and a second group of inflatable regions, the inflatable regions of said first group of inflatable regions being generally interleaved with and isolated from the inflatable regions of said second group of inflatable regions, a first fluid flow means connected to supply fluid to said first group of inflatable re-' gions, a second fluid flow means connected to supply fluid to said second group of inflatable regions, a pure fluid bistable element having an interaction region, at least a first output passage and a second output passage, a power nozzle for issuing a power stream of fluid through said interaction region toward said output passages, means connecting said first and second output passages to said first and second fluid flow means, respectively, first means responsive to inflation of said first group of inflatable regions for switching the power stream from said first output passage to said second output passage, and'means responsive to inflation of said second group of inflatable regions for switching the power stream from said second output passage to said first output passage.
12. An inflatable member and control therefor comprising an inflatable member having at least two inflatable regions isolated from one another, a first fluid flow means connected in fluid flow relationship to a first of said inflatable region, a second fluid flow means connected in fluid flow relationship to a second of said inflatable regions, a pure fluid bistable element having an interaction region, at least a first output passage and a second output passage, a power nozzle for issuing a power stream of fluid through said interaction region toward said output passages, means connecting said first and second output passages to said first and second fluid flow and second control means responsive to inflation of saidsecond inflatable region to switch said power stream from said second output passage to said first output passage.
13. The combination according to claim 12 wherein said first control means comprises a first feedback means responsive to pressure in said first output passage for issuing fluid into said interaction region in such a sense as to deflect said power stream from said first output passage to said second output passage.
14. The combination according to claim 13 wherein said second control means comprises a second feedback means responsive to pressure in said second output passage for issuing fluid into said interaction region in such a sense as to deflect said power stream from said second output passage to said first output passage.
15. The combination according to claim 14 wherein said flip-flop includes a first control nozzle disposed on the same side of the centerline of said power nozzle as said first output passage, and a second control nozzle disposed on the sameside of the centerline of said power nozzle as said second output passage, said first feedback means extending between said first output passage and said first control nozzle and said second feedback means extending between said second output passage and said second control nozzle.
16. The combination according to claim 14 wherein said pure fluid bistable element is of the type in which switching is insensitive to backloading of said output passages in the absence of said first and second feedback means.