CA1178719A

CA1178719A - Air mat apparatus

Info

Publication number: CA1178719A
Application number: CA000413346A
Authority: CA
Inventors: Masatoshi Takeuchi
Original assignee: Seiken Co Ltd
Current assignee: Seiken Co Ltd
Priority date: 1981-10-13
Filing date: 1982-10-13
Publication date: 1984-11-27
Also published as: JPS5858034U; FR2514254A1; DE3237610A1; JPS6038993Y2; FR2514254B1; GB2107197B; GB2107197A

Abstract

AN AIR MAT APPARATUS

ABSTRACT OF THE DISCLOSURE

An air mat apparatus comprises a mat body, an air source for feeding the mat body with air and a changeover valve connected between the air source and the mat body, the mat body being divided into a plurality of airtight chambers in grid-like arrangement, each airtight chamber being connected through an air pipe to the changeover valve, the changeover valve comprising a valve body and a drive motor for driving the valve body, the valve body comprising a changeover element driven by the drive motor and a cylin-drical casing into which the changeover element is airtightly inserted so as to be rotatable.

Description

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DETAILED DESCRIPTION OF THE I~VE~TION

The present inventiGn relates to an air mat apparatus which is mainly laid on a bed or chair or wound round a hand or leg in order to promote the blood circu-lation or the body surface, to prevent bedsores or to massage the waist, back, hand, leg or the like, and relates especially to an air mat apparatus in which the pressure applied on the body surface is easily changealbe.

Prior Art An air mat in which compressed air is introduced into an airtight bag has been already put to practical use.
However, an air mat the whole surface of which is always pushed by air pressure hinders the blood circulation at the human body surface when used. This is not limited to such an air mat but also an air mat formed of urethane foam has the same disadvantage. Therefore, patients who cannot move on the bed e.g. those in seriously illness or affected by an atrophy of muscles have bedsores and suffer from the weakening of internal organs, especially digestive organ like intestines. In order to prevent this, a new bed has been developed. The bed has two tilting plates on either side, and by alternately tilting each of the tilting plates, the patient on the bed is moved aside at a given time's 11'7~71~
interval. But such a bed is expensive because the structure for shifting the upper surface of the bed is complicated, and since such a structure cannot be easily mounted on a conventional bed, it has been designed for exclusive use.
Further disadvantageously, such a bed is apt tO cause mechan-ical noises when tilted. Furthermore, in such a bed provided with tilting plates, it is structurally difficult to partially change the pressing force applied on the body surface by the bed, and thus all the patient cannot use the bed in the best condition and the use is remarkably limited. In an apparatus for promoting blood circulation by pressing parts of the human body surface, it is preferable that the pressure applied on the body surface is adjustable in accordance with the use purpose, liking of the user, the way of use and the like. The inflation and deflation of the parts of an air mat can be adjustable by connecting the devided airtight chambers of the mat through separate electromagnetic valves to an air source and controlling each electromagnetic valve for example, by means of timers. According to this system, however, such an air mat costs very high since a number of expensive electromagnetic valves are required. Besides, loud noises generate when the valves are opened or closed, and such an air mat is not suitable for practical use.

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~rief Sul~nary of the Invention The present invention is developed in order to eliminate all of tne abovementioned disadvantages of the conventional air mat. An important object of the present invention is to provide an air mat in which the whole body and the changeover valves are simple in structure and inexpensive noises hardly generate when the changeover valves are operated; the pressure applied on the human body by the mat is adjustable by simple operations: a number of airtight chambers can be controlled by a single changeover valve, and which is durable, trouble-freè, and easily maintained and treated.
The above and further objects and novel features of the invention will more fully appear from the following detailed description when the same is read in connection with the accompanying drawing. It is to be expressly understood, however, that the drawing is for purpose of illustration only and is not intended as a definition of the limits of the invention.

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Detailed Description Now, examples of the present invention will be described blow with reference to the appended drawings, in which:
Fig. 1 is a schematic plan view of an example of the air mat apparatus according to the present invention;
Fig. 2 is a sectional view showing the connection between the airtight bags and the air pipe;
Fig. 3 is a side view showing the air mat apparatus in used state;
Fig. 4 is a perspective view of the air mat apparatus in another used state;
Fig. 5 is a plan view of a mat body to be wound round an arm or legi 71~

~ ig. 6 is an enlarged sectional view of the important portion of the mat body;
Fig. 7 is a longitudinal sectional view of the valve body;
Fig. 8 is an exploded view of the air inlet and out-let recesses;
Fig. 9, 10 are lateral sectional views of the valve body showning examples of the connection between the valve body and the mat body;
Fig. 11, 12 are perspective views of other examples of the changeover elements;
Fig. 13 is a sectional view of the changeover element inserted in the casing; and Fig. 14, 15 are sectional views of the connectors connected in the way of the air pipe.
An air mat apparatus shown in Fig. 1 comprises a mat body 1, an air source for feeding the mat body 1 with pressed air, and a changeover valve 2 connected between the mat body 1 and the air source.
The mat body l comprises a number of tubular air-tight bags each defining an airtight chamber, and a cover 4 in which the airtight bags are contained in grid-like arrangement. The airtight bags 3 are formed of natural or synthetic rubber-like resilient material or flexible synthetic resin sheet so that they can be inflated and deflated.

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Th~ co~er 4 is rormed ~y sewing into sha~e of nonresilient or subs~alltially nonresilient sheet material such as cloth so that the dimensions of the inflated airtight bags are limited to a constant values even if the pressure of the introduced air somewhat changed. The preferred dimensions of the airtight bag 3 is decided to be optimum values in accordance with the use purpose, but usually the outer diameter of the inflated airtight bag is selected as 2 to lOcm~ while the length thereof is 30 to 150cm. To one end of the airtight bag 3, a short rigid tube 5 is fixed in an airtight manner as shown in Fig. 2, and an air pipe 6 is fitted on the tube 5 so as to be connected thereto.
When the air mat apparatus is laid on a bed as shown in Fig. 3, the dimensions of the airtight bags 3 are preferably selected so that the length of the airtight bags 3 corresponding to the human body is much larger than the breadth of a user's shoulders and the diameter of the airtight bags corresponding to the waist is somewhat large while that corresponding to the shoulder blades is somewhat small.
When a mat body 1 is to be wound round an arm as shown in Fig. 4 or a leg (not shown), the airtight bags are in grid-like arrangement as shown in Fig. 5 so that each airtight bag is wound round the arm or leg, that is, the airtight bags are in the lateral direction with respect to the length of the arm or leg.

Fig. 6 shows the sectional view of the cover 4.
The cover 4 comprises two sheets of cloth connected by sewing so as to define container sections for the airtight bags arranged grid-like manner. The whole shape of the mat body 1 must not change whether the airtight bags are inflated or deflated. In order to realize this, in the cover 4, the lower sheet is laid in plane and the upper sheet in a laminated form is connect by sewing onto the lower sheet. Therefore, when the airtight bags are inflated, only the upper sheet of the cover is expanded.
The distance between two adjacent airtight bags is selected to be shorter than half the sum of the diameters of the two adjacent airtight bags. This is shown in Fig. 6.
In Fig. 6, the distance W between the center of the airtight bag 3 at the center and the adjacent airtight bag 3 is e.g.
several milimeter shorter than half the sum of the diameters dl, d2 of the central airtight bag 3 and the adjacent airtight bag 3 respectively.
With this shape, when a plurality of airtight bags are inflated, an airtight bag 3 is pushed by the lateral pressure the adjacent airtight bags 3 and the side surface is recessed. This recess generates an upward pushing force of the airtight bag 3; Consequently, the airtight bag 3 in the middle portion becomes higher and the whole of the airtight bag is in the shape of an arc. Thus, the human body surface 1.~ 7(~719 is erfectively pushed and at the same time, the recesses defined between inflated airtight bags 3 are reduced.
The container section 7 o~ the cover 4 is opened or can be opened at one end. The airtight bag 3 is inserted into the container section and it can also taken out. The air pipe 6 is removably connected to the tube 5 of the airtight bag 3. If an airtight bag comes in trouble during the time of use, it is taken out of the container section 7 of the cover 4 and a new one is inserted thereinto to which the air pipe is reconnected.
As the air source, an air pressure pump 8 of 50 to 300mmHg discharge pressure or a combination of a reduc-tion valve 9 and a pressure air tank 10. When the pressure air tank 10 is used, high pressure air in the tank 10 is reduced to 50 tO 300mmHg by means of the reduction valve 9 and then fed into the airtight bags.
The airtight bags 3 can be deflated only by commu-nicating the airtight bags through the changeover valve 2 with the discharge side so that the airtight bags are opened to the outer air. However, it is preferable that the airtight bags are compulsorily deflated by discharging air out of the airtight bags by means of an air discharge pump. For this purpose, an air discharge pump 11 and the air source are connected to the changeovervalve- 2.
The changeover valve 2 comprises a valve body 12 11'7~

and a drive motor 13 for driving the valve body 12. The valve body 12 ccmprises a changeover element 14 adapted to be rotated by the drive motor 13 and a casing 15 into which the changeover valve is rotatably inserted.
The changeover element 14 is provided with a diaphragm 29 having a circular outer periphery. The outer circumferencial surface of the diaphragm 29 is in airtight contact with the inner surface of the casing 15 and slidable in the casing 15. An air inlet recess 15 is provided on one side of the diaphragm 29 and an air outlet recess 17 on the other side thereof. The air inlet recess 16 and air outlet recess 17 are provided adjacent to each other in the direction of the rotation of the changeover element 14 so that through the rotation of the changeover element 14, an air outlet opening 18 provided in the casing 15 can be alternately communicated with either of the air inlet and outlet recesses 16, 17.
In the valve body 12 shown in Figs. 7 to lO, the ratio between the inflation and deflation times of the airtight bags can be changed by displacing the casing 15 in the axial direction. That is, the number of the airtight bags to be inflated as a group can be changed.
Fig. 8 is an exploded view showing the air inlet recess 16, the air outlet recess 17 and the diaphragm 29.
In this figure, the air inlet recess 16 is so fomed that 1.~7~7~9 it becomes narrower in the axial lirection and has a tapered end. T~e air outlet recess 17 is provided adjacent to the air inlet recess 16 and circumferentially spaced from the latter by the width S of the diaphragm 29. The width of the air outlet recess 17 changes in the axial direction.
The air inlet and outlet recesses 16, 17 are separately communicated with introduction recesses 19, 20 respectively so that the air inlet recess 16 is always communicated with the air source and the air outlet recess 17 is always communicated with the air discharge pump 11.
The introduction recesses 19, 20 are provided on either side of the air inlet and outlet recesses 16, 17 and throughout the outer circumference of the changeover element 14.
As shown in Fig. 1, one end of the changeover element 14 is connected to the drive motor 13 by coupling 21 so that the changeover time can be controlled by changing the rotation number of the drive motor 13.
The casing 15 is formed of a cylinder with two ends opened into which the changeover element 14 can be airtightly and rotatably inserted. In Fig. 7, the right side end of the casing 15 is inserted by means of a key 22 or spline into a fitting stand 23 so as not to rotate but to slide in the axial direction. Further, at the right side end of the casing 15, an external screw is provided on the outer circumferential surface. Furthermore, air openings 18 uniformly spaced in the circumferential direction of the casing 15 715~
are provided and each air opening penetrates the casing 15 in the radial direction. On either side of the air openings, an ai.- inlet opening 24 and an air outlet opening 25 are provided.
The air openings 18 are arranged in correspondance with the locus of the displacement of the diaphragm inter-posed between the air inlet and outlet recesses 16, 17 on the outer surface of the changeover element. The air inlet opening 24 is posi.tioned in correspondance with the intro-duction recess 19 communicated with the air inlet recess 16, while the air outlet opening 25 is positioned in correspondance with the introduction recess 20 communicated with the air outlet recess 17~
The external screw of the casing 15 is in the threaded engagement with the internal screw provided in a tongue 26. The tongue 26 is fitted through a setscrew 27 to the fitting stand 23 so as to be rotatable but not movable in the axial direction. Therefore, on the outer circumferential surface of the fitting stand 23, an annular groove 28 is provided in which the setscrew 27 slides.
With the rotation of the tongue 26, the casing 15 is displaced in the axial direction and the positions at which the air opening 18 pass the air inlet recess 16 and the air outlet recess 17 change, whereby the state of the communication of the air opening 18 with the air inlet and outlet recesses 16, 17.

11'7~719 ~ n Fig. 7, when the casing 15 is displaced to the righ~, the nu~er of the air openings 18 communicated with the air inlet recess lo decreases, and the inflated airtight bags decreases in number.
When the casing 1~ is displaced to the rightmost position, less than one air opening 18 is communicated w~th the air inlet recess 16.
In the changeover valve shown in Fig. 7, with the displacement of the casing 15 in the axial direction, the casing 15 and the changeover valve are relatively displaced in the axial direction. However, if the changeover element is displaced in the axial direction with respect to the casing, the same movement can be obtained. In this case, though not shown, a drive motor connected to the changeover element is fitted to a base so as to be movable in the axial direction, and the changeover element is displaced together with the drive motor.
The air opening 18 is connected through the air pipe 6 to the airtight bags 3, and the air inlet opening 24 is connected to the air source, w~lile the air outlet opening 25 is opened ~o the outer air or connected to the air discharge pump 11.
Fiys. 11 to 13 show other changeover elements 14 having different structures.
Tn the c~angeover element 14 shown in Fig. 11, li~7~7 1~

two discs 31, 32 are fixed at both ends of a shaft 30 so that the outer circumferences of the discs are in airtight contact with the inner surface of the casing. Between the two discs 31, 32, the diaphragm 29 the outer periphery of which is in airtight contact with the inner surface of the casing is inclinedly fixed. And the air inlet and outlet recesses 16, 17 are interposed between the diaphragm 29 and the discs 31, 32 respectively.
In a cylinder into which the changeover element 14 is inserted, the inlet opening is provided so as to be communicated with the air inlet recess 16 and the air outlet opening is provided so as to be communicated with the air outlet recess 17, while the air opening is provided in the sliding surface of the outer periphery of the diahpragm 29.
In the changeover element 14 shown in Fig. 12, two discs 31, 32 are fixed at both ends of the thick shaft 30 and the diaphragm 29 is inclinedly fixed between the discs 31, 32. The discs 31, 32 and the diapharagm 29 have such diameters respectively that they can rotate with their outer circumferential surface being in airtight contact with the inner surface of the casing 15 as shown in Fig. 13.
It is advantageous that the changeover element 14 shown in Figs. 12, 13 can be easily manuractured.
In usual use, air openings 18 are successively connected to the airtight bags 3 as shown in Fig. 9.

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In order to slowly rotate the changeover element 14 and thus to raise the speed of displacement of the inflated airtight bags 3, the neibouring air openings 18 are connected to the airtight bags at a few bags apart as shown in ~ig. 10.
If the airtight bags are more than the air openings in number, a plurality of airtight bags are connected to an air opening.
The air pipe 6 is removably connected to the change-over element 12, so that the inflated or deflated states of the airtight bags can be changed by changing the connec-tion of the air pipe to the changeover element 12. The air pipe 6 is formed of a flexible synthetic resin tube.
- As shown in Figs. 14, 15, it is possible that a connecting means 33 is connected in the way of the air pipe 6 and the connection of the air pipe 6 is changed by the connecting means 33.
The connecting means 33 comprises a body 33A to both ends of which air pipe is connected, and a slider 33B
removably and airtightly fitted to the body 33A.
The body 33A is formed of a cylinder into which the slider 33 is inserted. Opposed air openings 34 are opened into the hollow of the body 33~. The slider 35 is provided with communication bores which can communicate the opposed air openings 34 with each other when the slider 35 is inserted l t'~719 into the body 33A. lrhe communication bores are provided in parallel as shown in ~ig. 14 or provided to penetrate through the slider 33B according a given rule and without any commu-nication with one another. By changins the pushing condition of the slider 33B, the connection between the changeover ~alve 2 and the mat body 1 is changed and the inflation and deflation of the mat body 1 is controlled.
In the air mat apparatus having the abovementioned structure, the changeover valve connected between the mat body and the air source comprises the drive motor and the valve body, the valve body comprising the changeover element driven by the drive motor and the casing in which the change-over element rotates in the airtight manner, the changeover element being provided on its outer circumferential surface with the air inlet recess and the air outlet recess neibouring to but not communicated with each other, the boundary of the air inlet and outlet recesses being inclined in the direction of the circu~ference of the changeover element, thus the widths of the air inlet and outlet recesses changing toward the circumference of the changingover element so that as the air inlet recess becomes broader the air outlet recess becomes narrower, on the o-ther hand, the casing into which the changeover element is rotatably inserted being provided with a plurality of air openings in correspondence with the air inlet and outlet recesses, and the casing being fitted so as not to rotate but to move in th~ axial direc~ion, i71~
and ~herefore, by displacing the casing in the axial direction ar.d rotating the changeover element, the state of the commu-nication of the air openings with the air inlet and outlet recesses can be changed. Consequently, by displacing the casing in the axial direction, the numbers of the inflated and deflated airtight.bags connected to the air openings can be changed, and the user can conveniently use the air mat apparatus always at the most suitable condition for his liking, and the way and purpose of use.
Further, in this air mat apparatus, the mat body is divided into a plurality of defined airtight chambers, air being introduced under pressure out of the airtight chambers and discharged therefrom so as to inflate and deflate the airtight bags, further, the changeover valve comprising a casing into which a changeover element provided with two recesses is inserted and rotated, and therefore, the structures of the whole apparatus and the changeover valve being simplified and manufactured at low cost, the changeover valve, unlike an electromagnetic valve, never generating any uncomfortable noises when operated, that is, the air mat apparatus being operated quietly, the pusing force applied to the human body surface being easily controlled only by displacing the casing, a number of airtight chambers being controlled by means of a single changeover valve, and further, the air mat apparatus can realize many effects such 3 ~7~719 as durability, troublerree ~uality and so forth superior to other air mat apparatus.

Claims

What is claimed is:

1. An air mat apparatus comprising a mat body, an air source for feeding the mat body with air, and a changeover valve connected between the air source and the mat body, the mat body having a plurality of defined airtight chambers in grid-like arrangement, each airtight chamber being connected through an air pipe to the changeover valve, the changeover valve comprising a valve body and a drive motor for driving the valve body, the valve body comprising a changeover element driven by the drive motor and a cylindrical casing into which the changeover element is airtightly inserted so as to be rotatable, the changeover element being provided with a diaphragm having a circular outer periphery, the outer circumferential surface of the diaphragm being a slide surface which is in slidable and airtight contact with the inner surface of the casing, an air inlet recess being provided on one side of the diaphragm and also an air outlet recess on the other side thereof, further, the slide surface of the diaphragm being inclined with respect to the circular periphery so that with the rotation of the changeover element within the casing, the diaphragm difining the air inlet and outlet recesses can be movable in the axial direction, the casing having a cylindrical hollow portion so that the outer circumferential surface of the diaphragm of the changeover element can be in slidable and airtight contact with the inner surface of the casing, the casing being provided with an air inlet and outlet openings always communicated with the air inlet and outlet recesses respectively, the casing, being further provided with a plurality of penetrating air openings in correspondence with the locus of the rotation of the outer circumferential surface of the diaphragm obtained by the rotation of the changeover element, the casing being connected to a fitting stand so as not to rotate, the casing and the changeover element being relatively movable in the axial direction, the air openings of the casing being connected through air pipes to the airtight chambers, the air inlet opening being connected through an air pipe to the air source, the air outlet opening being opened into the outer air or connected to an air discharge pump, with the rotation of the changeover element by means of the drive motor the connection of the air opening with either of the air inlet recess or the air outlet recess being changed-over whereby the alternate inflation and deflation of each airtight chamber is repeated, further with the displacement of the casing in the axial direction the ratio of the times when each air opening is connected to the air inlet recess and the air outlet recess being changed whereby the inflation and deflation of the airtight chambers can be controlled.

2. An air mat apparatus as claimed in claim 1, in which the drive motor is a gear-shifting motor.

3. An air mat apparatus as claimed in claim 1, in which the casing is mounted so as to be movable in the axial direction.