US3462778A - Inflatable mattress and pressure system - Google Patents

Description

Aug. 26,1969 J. K, WHITNEY INFLATABLE MATTRESS AND PRESSURE SYSTEM 3 Sheets-Sheet 1 Filed Feb; 25, 1966 Aug.v 26,v 1969 J K WHWNEY 3,462,178

` INFLATABLE MATTRESS AND PRESSURE SYSTEM Filed Feb. 25', 1966' 5 sheets-sheet 2 IN VEN TOR. @HN K. WHITNEY BY HM ATTORNEY Aug. 26, 1969 J, K. WHITNEY 3,462,778

v INFLATABLE MATTRESS AND PRESSURE SYSTEM Filed Feb. 25. 1966 '-5 sheets-sheet s 160 .fao 20o 22o 240 26o fao ab 32o 340360 #om z-i- #ULD-bm Y MwST--v Y k--mw--m /NPUT 1N VENTOR. JoH/v K. WH/TNEY B Y @MQ/ff ATmRNfY United States Patent O 3,462,778 INFLATABLE MATTRESS AND PRESSURE SYSTEM Iohn K. Whitney, Orchard Park, N .Y., assignor to Gaymar Industries Inc., a corporation of New York Filed Feb. 25, 1966, Ser. No. 530,164 Int. Cl. A47c 27/ 08 U.S. Cl. 5-347 4 Claims ABSTRACT 0F THE DISCLOSURE A multiple cell, fluid pressure system utilizing a valve which substantially fills one set of cells before exhausting the other set of cells whereby movement of a patient thereon is held to a minimum in a horizontal plane.

'This invention relates to a therapeutic mattress and pressure system adapted to provide cycling alternate adjoining body support areas for the user.

Persons required to lie in bed for an extended period of time suffer the discomforts of general fatigue, muscular pains, and in some instances, decubitus ulcers or pressure sores. In order to relieve these conditions, it has been proposed that multiple cell uid or air mattresses be employed with a pressure system to alternately shift the body support pressure areas from one location to another. Although such prior mattresses have reduced the discomforts of the user, they have not satisfied the prerequisites required to adequately insure against tissue degeneration nor have they provided efficient and relatively maintenance-free operation during an extended period of usage.

It is known that certain bony parts of the body such as heels and shoulders are more prone to become sore during convalescence than other parts of the body. Further, the area of these parts which contact the mattress is relatively small compared to the size of the mattress cells normally used. Consequently, even though the adjoining cells are alternately inflated and deflated, the small body areas often remain xed in pressure point location upon lone cell width.

Accordingly, an object of this invention is to reduce the mattress cell width in those sections of the mattress which normally support the small bony areas of the body to better assure a transfer of the support areas between adjoining cells.

It is also known that therapeutic mattresses employing cells having more than one width dimension have been proposed. For instance, one such mattress employs essentially bifurcated cell extensions of larger longitudinal cells located at the bottom of the mattress. It has been found that such mattresses fail to combat tissue degeneration at several of the small bony areas of the body mentioned above. Further, these known mattresses, because of their simplicity of cell layout and minimum seal joints, are relatively weak and therefore with not withstand extended usage. Also, such mattresses are not reversible, thereby hastening failure, and they additionally lack universality for positioning purposes.

Accordingly, a further object of this invention is to provide greater comfort for the user, and reversibility and universality of the mattress by employing smaller cells at prescribed locations on the mattress.

Another object of the invention is to make the mattress more rugged by fabricating the cells in at least three sections, the center section cells being larger in width than the outer section cells.

When a person is lying on an alternating pressure support mattress, some disturbance occurs when the supported height of the body is changed. This has been evident in some prior mattress designs which allowed the user 3,462,778 Patented Aug. 26, 1969 to move alternately from a relatively high position when one set of cells was fully inflated to a relatively low position whereat the adjoining cells were at an equal level and pressure. Such cyclic vertical movement is bothersome to the user.

Accordingly, a further object of the invention is to transfer the body support areas from one cell to the adjacent one at a time when both cells are substantially fully inflated to minimize vertical movement of the user.

A still further object of the invention is to provide an improved therapeutic mattress and iluid pressure system.

The foregoing objects are achieved in one aspect of the invention by the provision of an inflatable mattress having at least three sections, each of which includes two sets of interdigitated cells. The outer section cell sets utilize cells having a width substantially less than the central section cells. A fluid pressure system is connected to the mattress to provide alternate inflation and deation movements of the adjoining interdigitated cells. This system operates in a manner to maintain one set of cells in an inated position while the other set of cells is deflated and then substantially inflated again. Accordingly, although the users pressure points on the mattress change position from one cell to the adjoining cell during each cycle of operation, the actual transfer of the support areas occur without substantially altering the support height of the user.

For a better understanding of the invention, reference is made to the following description and accompanying drawings in which:

FIG. 1 is a plan view of the inatable mattress coupled to the pressure system;

FIG. 2 shows the manner in which the pressure system valve is mounted;

FIG. 3 is a view taken along line 3-3 of FIG. 2 of the stationary member of the valve;

FIG. 4 is a view taken along line 4-4 of FIG. 2 showing the rotating valve member; and

FIG. 5 is a chart illustrating the operation of the valve in the pressure system as well as the inflation and dellation movements of the adjoining mattress cells.

Referring generally to FIG. l, mattress 11 is provided with two sets of interdigitated cells 13 and 15 formed by seal ribbons 17. Access connections 19 and 21 are attached to cell sets 13 and 15, respectively. Fluid pressure is supplied to mattress 11 from pump 23 through chamber 25, conduits 27 and 29 and valve 31. The fluid pressure from the valve is transferred to the mattress by conduits 33 and 35. An adjustable pressure relief valve 24 is also connected to chamber 25 to insure maintenance of proper pressure in the system.

More specifically, mattress 11 may be formed from two rectangular vinyl chloride sheets of .020 inch thick plastic matterial having a peripheral contour similar to a typical hospital bed mattress. The sheets are attached to one another by seal joints indicated by ribbons 17 around the periphery. Similar seal ribbons form the separating fluid impervious joints between cell sets 13 and 15.

As indicated in FIG. 1, the mattress is formed with at least three distinct sections 37, 39, and 41. The peripheral channels 43 and intermediate channels 45 serve to interconnect the respective cell sets 13 and 15 so that a given cell set in each mattress section inflates and deflates along with its counterpart in the other sections.

It is to be noted that access connections 19 and 21 may be disposed at both ends of mattress 11. Also, the configurations of outer sections 37 and 41 substantially conform to one another. Accordingly, such a layout of cells and access connections provides reversibility for the mattress. Suitable plugs 48, clamps or other means may be employed to seal olf the connections 19 and 21 which are not being used at the time.

The mattress is more rugged than previous ones for several reasons. For instance, the three mattress sections 37, 39 and 41 individually have a large number of seal joints along ribbon 17 with few interconnecting ribbon lines. Further, in areas where terminations or relatively sharp corners would be encountered such as at the corners of the cell sets 13 and 15 in central section 39, circular seal ribbons 47 are provided for strength,

Central section 39 uses relatively wide cell widths for interdigitated cell sets 13 and 15. Normally, such cells are arranged longitudinally to contact the trunk portion of the patient. It has been found that cell widths of about 1.75 inches are quite satisfactory for the central section cells.

The cells of sets 13 and 15 in the outer sections 37 and 41 generally are positioned longitudinally of the mattress to reside where the rather small bony areas of the body rest. Two such areas are the heels and certain parts of the shoulder. Due to the relatively small size of these bony areas, it has been found beneficial to make the cells in outer sections 37 and 41 substantially smaller than those in central section 39. For example, cell widths for sets 13 and 15 in these outer sections may have a width of about 1.00 inch. Accordingly, the adjoining interdigitated cells are sufficiently small to transfer the pressure support point from one cell to the other even for the small bony parts of the body that they contact.

With respect to the fluid pressure system, pump 23 may be any conventional air pump, preferably of the continuously operating diaphragm type capable of delivering about .75 p.s.i. Chamber 25, which may be made of plastic, serves as a pressure pulse damper and a noise suppressor. The pressure relief valve preferably comprises a variable control bleeder type valve.

Referring to FIGS. 2, 3, and 4, valve 31 employs a stationary member 51 and a rotating member 53. These members have flat faces 55 and 57 which are formed to mate in a substantially air tight manner. Members 51 and 53 are molded from graphite so that there is little friction and a good hermetic seal between faces 55 and 57.

The valve 31 is mounted on bracket 59 attached to the pressure system chassis, not shown, by means of motor shaft 61 and spring 63. The shaft is driven by an electric clock motor 65 through a gear reduction mechanism 67. Rotating member 53 is affixed to shaft 61 by means of a cotter pin 69 nesting in slot 71. Spring 63 presses against stationary member 51 to assure that the flat faces 55 and 57 remain in intimate contact. The shaft passes through member 51, which is held against rotation by the conduit lines 27, 29, 33 and 35. It is to be noted that very little turning force is exerted on stationary member 51 during rotation of member 53 because of the low friction.

During operation, the clock motor 65 runs continuously to drive shaft 61 and rotating member 53, while stationary member 51 remains in fixed position pressing against member 53 by action of spring 63. It has been found that 15 revolutions per hour of member 53 is satisfactory. This gives a cycle time of four minutes during which the cell sets 13 and 15 in mattress 11 proceed through one alternation of inflation and deflation by virtue of the full revolution of rotating member 53.

FIGURES 3 and 4 illustrate the details of valve 31. Stationary member 51 has a central opening 73 through which the rotating shaft 61 passes. Oppositely disposed inlet ports 75 and 77 extend into the body of member 57 and terminate in openings 79 and 8-1 respectively on the flat face 55. These inlet ports are preferably located with centers lying on an inner concentric circle. Discharge ports 83 and 85, which are connected to cell sets 13 and 15 through couplings 33 and 35, also extend into the body of member 51 and terminate at openings 87 and 89 respectively on face 55. The discharge ports terminate at positions lying on an outer concentric circle.

Accordingly, air is supplied to stationary member 55 through inlet ports 75 and 77 and discharged to the mattress through ports 83 and 85.

The rotating member 53 of the valve has a central opening 91 for shaft 61. This member is affixed to the shaft and rotates therewith by virtue of the nesting relationship of cotter pin 61 in slot 71.

The flat face 57 of rotating member 53 is provided with an arcuate air transfer groove 93 and an arcuate air exhaust groove which has an opening 97 to the atmosphere. The arcuate length of groove 93 is less than of rotation by approximately the diameter of openings 87 and 89. The radial width encompasses both of these openings. The width and length has to be suicient to straddle an inlet port opening and a discharge port opening to transfer the air to the mattress cells. However, the arcuate length preferably is less than that required to straddle both discharge port openings 87 and 89 since there is no desire to connect the cell sets 13 and 15 to a common pressure source for a period of time sufiicient to cause the pressure in both cell sets to equalize. When this occurs, both cell heights drop and then one of them will rise again to a fully inflated position. This up and down movement is disturbing to the patient.

Arcuate discharge groove 95 has a location and radial width such that it only intercepts discharge port openings 87 and 89 in member 55 during rotation. The length of groove 95 is sufficient to straddle one discharge port at a time. When the groove is over one of the discharge ports, the mattress cell set connected at that port is dellated by exhausting to the atmosphere through opening 97.

Face 57 of member 53 is provided with lands 99 and 101 lying between grooves 93 and 95. During rotation, the arcuate lengths of these lands determine the hold period between the inflation and deflation cycles of the apparatus. Also, land 101, in conjunction with the speed of rotation and the pressure in the system, determines the length of time needed to hold an inflated cell set in that condition so that the other cell set can be substantially inflated before the first set is exhausted. As mentioned previously, this condition is desirable so that the patient does not sense any appreciable vertical movement on the mattress while the pressure support points on his body are being transferred between adjoining cells.

FIG. 5 will aid in an understanding of the operation of the inflation and deflation cycle of the mattress cells as well as the pressure system valve sequence. Presume that cell set 13 is deflated and cell set 15 is inflated and holding at the beginning of a cycle, and that rotating member 53 is moving counter clockwise approximately from the position shown in FIG. 4. Arcuate groove 93 will first encounter opening 87 of discharge 83 and co'nnect it with inlet port 75. This causes the air to be supplied to cell set 13 in the mattress 11. The cells of set 13 proceed to inflate, and, approximately at the time they reach full inflation, discharge arcuate groove 95 intercepts opening 89 of port 85. This causes cell set 15 to deflate by exhausting to atmosphere through opening 97. During continued rotation of member 53, port 83 remains connected to the source of air pressure first through port 79 and then port 77. At the same time, cell set 15 is being exhausted through groove 95 and is finally held in that condition by land 99. At this point, member 53 has rotated about member 51 about 180 from the initial assumed starting position. The alternate inflation-deflation sequence of the mattress cells then begin. Grove 93 now moves over port S5 leading to the deflated cell set 15 and begins to inflate these cells. At the same time, land 101 is positioned over opening 87, thereby holding cell set 13 in the inflated condition. This hold period may last for about 50 degrees of rotation, after which exhaust groove 95 encounters port opening 87 to cell set 13 to begin exhausting. Here again, the timing between exhausting of cell set 13 and full inflation of cell set 15 is such that the patient senses no up and down movement during transfer upon the support cells. Some overlap of the iniiated hold period on one cell set with the full inflation period of the other set can be tolerated by the patient. However, it is not desirable to shorten the inilated hold position to the extent that the other set is not near full inflation since it will cause patient movement as pointed out above.

During the iinal rotational movement to complete the 360 cycle, groove 93 remains in contact iirst with port 77 and then 75 to maintain cell set 15 inflated. During this same period, groove 95 is straddling port 83 and land 99 to maintain cell set 13 in .a deated condition.

It can be readily understood from the above description that this invention provides an improved fluid pressure system and therapeutic mattress formed to produce cycling alternate adjoining body support areas for the user. The mattress is rugged and formed for comfort, therapeutic value, reversibility and universality. Further, the pressure system is unique and eicient, and it relieves the patient from the discomfort of vertical movement experienced with prior mattresses.

What is claimed is:

1. In a uid pressure system, the combination of an inflatable mattress formed to provide cycling alternate adjoining body support areas for the user having at least rst and second sets of sealed fluid impervious interdigitated cells with an access connection for each cell set, a continuously operating pump formed to provide fluid pressure, and a valve interconnecting said pump and said access connections for iniiating said cell sets, the valve comprising a stationary member and a rotating member, the stationary member having inlet ports coupled to the pump and spaced discharge ports coupled to the access connections of said mattress, each of said ports having an opening into a iiat face formed on said stationary member, the rotating member having a lat face formed to mate in a substantially Huid-tight relationship with the face of said stationary member, said rotating member face being formed to provide spaced arcuate grooves separated by lands, the arcuate grooves and lands being arranged to continuously block communication through the valve ports between said Iirst and second cell sets, the rst of said grooves having an arcuate length sufficient to straddle an inlet and discharge port, the second of said grooves having an exhaust opening to atmospheric pressure, the grooves and lands further being arranged relative to the stationary member ports during rotation to sequentially maintain each set of cells inflated while the other set is deflated and then substantially inated to provide alternating support on adjoining areas of the mattress without substantially altering the support height of the user.

2. A system in accordance with claim 1 wherein the fluid pressure is suliicient to inflate a set of said cells through the valve in less than half the degrees of movement of said rotating member during the period when the first of said arcuate grooves is in communication with an inlet and discharge port.

3. A system in accordance with claim 1 wherein a land separating the lirst and second grooves is of suicient arcuate length to maintain iiuid pressure in one of said cell sets until the second of said cell sets is substantially inflated.

4. A system in accordance with claim 3 wherein the stationary valve member has two oppositely disposed discharge ports terminating on an outer concentric circle and two oppositely disposed inlet ports terminating at positions arcuately positioned between said discharge ports on an inner concentric circle, the first groove of said rotating member having a radial width sufcient to encompass both said inlet and discharge ports and the second of said grooves having a radial width sufficient to encompass only said discharge ports.

References Cited UNITED STATES PATENTS 1,772,310 8/1930 Hart 5-911 2,719,986 10/1955 Rand 5-348 3,199,124 `8/1965 Grant 5--349 3,388,701 6/1968 Schreiber et al. 128-33 CASMIR A. NUNBERG, Primary Examiner lANDREW M. CALVERT, Assistant Examiner U.S. Cl. X.R. 128-33

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