FLUIDIC PULSE GENERATOR AND MASSAGER AND METHOD

Abstract: This invention is a massaging system having at least a pair of fluid inflatable chambers (21, 22), and a fluidic switch (10) alternately connecting the at least a pair of fluid-inflatable chambers (21, 22) to a source of fluid (17) under pressure. The fluidic switch (10) is a crossover type fluid switch having a switching chamber (11) having two side walls (13, 14) in which fluid from the source (17) is switched from one side wall of the switching chamber to the other side of the switching chamber, is sensitive to load on the fluid inflatable chambers (21, 22), respectively, and vented passageways (19, 20) coupling the inflatable chambers (21, 22) to the switch.

Description: FLUIDIC PULSE GENERATOR AND MASSAGER AND METHOD REFERENCE TO RELATED APPLICATIONS This application is based on the following provisional applications: 1. No. 60/133,676 filed May 11, 1999 by Surya Raghu, Sean Burns and Dharapuram Srinath and entitled FLUIDIC PULSE GENERATOR/MASSAGER. 2. Serial No. 60/140,744, filed June 25, 1999 by Surya Raghu and titled METHOD AND APPARATUS FOR SUPPORTING FLUIDIC BLADDERS FOR MASSAGING ACTION. 3. Serial No. 60/163,154, filed Nov. 2, 1999 by Sean Burns and entitled DESCRIPTION OF SWITCHING DELAY MECHANISM IN A BACKLOADED FLUIDIC SWITCHING CIRCUIT FOR A SEAT MASSAGING SYSTEM. BACKGROUND AND BRIEF DESCRIPTION OF THE INVENTION The present invention relates to fluidic pulsing systems and method particularly suitable for use in physiotherapy systems such as fluid massaging systems in seats and in mattresses and the like. The system can be integrated into automotive and airline seats, for instance, or can be used in stand-alone massaging units which are used in homes, cars, etc. Fluidic oscillators used to generate pulses can be found in the prior art, in massaging showerheads, and to provide pulses for inflatable mattresses (see Jones Patent No. 3,390,674). Positive interaction region crossover-type fluidic switches have also been proposed. Positive interaction region crossover-type devices respond to loads by increasing the frequency of oscillation. This can be verified by measuring the frequency of inflation/deflation under unloaded (1.4 to 1.5 Hz, for example) and loaded (2.2 Hz, for example) conditions. In contrast, the present invention incorporates a negative interaction region fluidic switch device. The frequency of pulses under unloaded conditions is 2.2 Hz, for example, and when loaded slows down to 1.6 Hz. While these numbers were not measured with very high accuracy, the speeding up and the slowing down are unmistakable. The operating characteristics of the system are that, without backloading, it will not produce pulses. When the outlets are hooked up to inflatable chambers or bladders (elastic membrane), squeeze bottles (semi-rigid), and laboratory flasks (completely rigid), the operating frequency increased with each change (from elastic to rigid) which establishes that the backloading is creating the oscillations. It is difficult to create low-frequency oscillations of the range needed for massaging (less than 10 Hz) when utilizing a positive interaction region (self-sustaining) oscillator. The inherent oscillation mechanism has to be subdued and the external signals superimposed to create the low frequency. This has been done successfully with the current negative interaction region fluidic switch configuration of this invention. While it is certainly of interest to keep the system simple and economic, if desired, one could implement controls on these devices to control the frequency and amplitude. This may be done by the vent, change in supply pressure, a control port, or a combination. In the preferred embodiment, regularity or predictable sequencing of pulses is not desirable in massaging. Moreover, the fluidic device may be hooked up so that the air bags are not inflated in a particular order. However, the unit can be designed to produce either sequential or non-recognizable pulsation patterns. The dependence on the backloading will also cause the massage feel to be different each time the occupant moves or shifts weight. Although it is not directly related, reference is made to U.S. Patent No. 5,170,364 "Feedback System for Load Bearing Surface" to show the extent to which effort is spent to compensate for shifting loads. Most conventional commercial seat massaging systems in use are pneumatic systems with electromechanic controls. The controls, used in conjunction with mechanical components to create pulses, generally make for a complex system. According to the invention, the frequency should be in the order of about .5 - 2 Hz. At larger frequencies such as 10 Hz, it becomes into the range of a vibrator which in general are not as acceptable as a lower frequency massager. Moreover, the amplitude should be large, in the order of about .5 inch to 1 inch, as opposed to vibrators which are about one-tenth of that. Moreover, with the preferred embodiment, the rise and fall of the bladders or inflatable chambers should not be of a recognizable pattern. The present invention provides a fluidic massager and method which secures all of the above and, in particular, in a preferred embodiment, in a non-repetitive, non- recognizable pattern. This is achieved in three ways: In many embodiments, the outputs of the bladders or inflatable chambers are arranged in pairs where one airstream is alternately switched from one output passage to the other output passage. Equally loaded, the two bladders will be in opposite phase and be of a recognizable pattern. However, when the load is shifted more to one of the bladders, then that one takes longer to switch. This is a change in the pattern which is much like a duty ratio change. Device and configuration to obtain sequential and non-recognizable patterns are possible with the invention. Even when there is no shift in the load, the fluidic elements are free running. That is, they have no phasing interconnects so the pattern among pairs is always changing. Finally, the inflatable chambers or bladders can be arranged so that the pair mates are not located at positions which are regularly associated with each other. Thus, the invention provides a massaging system having at least a pair of air-inflatable chambers and a fluidic switch alternately connecting the bladders to a source of fluid under pressure which improvement in that the fluidic switch has a negative pressure interaction region and is a fluidic switch which is sensitive to backloading from on the bladders with the fluidic switch being coupled to the bladders by a pair of outlet passages leading to at least one vent coupled to the outlet passages. It is an object of the present invention to use fluidic circuits which can be subdivided into sections and therefore can be manufactured economically to provide a massaging function without any moving parts. In the preferred embodiment, negative interaction region fluidic switches are used to create pulses caused by resistance experienced by the output jet in traveling to fill a fluid (air or liquid) cell used for massaging and an atmospheric vent (for air). In other words, the backloading causes the switching. Further-more, the frequency of pulsing decreases when the user applies a load on the air cell which, in turn, will change the intensity of massaging sensations . Accordingly, another object of the invention is to provide an improved massaging system which reduces total system cost, improve massaging quality, reduces system maintenance and provides a very simple system compared to existing mechanical and pneumatic massaging systems. Summary of Advantages: When compared to conventional pneumatic or mechanical massage systems, the present invention offers: Lower cost, Greatly reduced system complexity, Reduced power consumption, No moving parts, Lighter weight, Fewer connection points, More robustness Easier packaging/installation, No wear points on seal foam due to mechanical roller massage contact, Cost effective vehicle differentiation, Luxury option availability on mid/low range cars, Adds massage to existing lumbar- support-only systems at minimal extra cost Higher commonality across vehicle lines. DESCRIPTION OF THE DRAWINGS The above and other objects, advantages and features of the invention will become more apparent when considered with the following specification and accompanying drawings wherein: Figure 1 is a schematic illustration of a pair of inflatable chambers coupled to a source of fluid under pressure via a pair of vented passageways and a backload responsive negative interaction region fluidic switch, Figure 2 is a diagrammatic illustration of a set of inflatable chambers coupled by vented passageways to a pair of crossover-type fluidic switches to a source of air under pressure, Figure 3 illustrates a fluidic switch of Figure 1 with stabilization feed back passages added, Figure 4 is a diagrammatic illustration of multiple fluidic switches which have negative pressure interaction regions which are sensitive to backloading, Figure 5 is a diagrammatic illustration of a fluidic circuit for producing sequential bladder inflation and deflation, Figure 6A is a plan view of a further embodiment and Figure 6B is an enlargement of a portion thereof, and Figure 7 is a diagrammatic illustration of a vehicle seat incorporating the invention. DETAILED DESCRIPTION OF THE INVENTION Referring now to Figure 1, the fluidic circuit 10 incorporates a negative interaction region switching chamber 11 having an upstream end power nozzle 12 with diverging and converging sidewalls 13 and 14, respectively, leading to an outlet throat 15 which has been widened or opened up so as to enable the interaction region to be negative pressure type and switch in response to backloading. The power nozzle 12 is coupled to a source of fluid under pressure such as an air pump 17 via a coupling passage 18. While the fluid under discussion is preferably air, it will be appreciated that other embodiments of the invention may use liquid such as water or oil. The outlet 15 is coupled to a pair of outlet passages 19 and 20, respectively, which lead to inflatable chambers or bladders 21 and 22, respectively. The passageways 19 and 20 have vent apertures 23, 24, respectively. It will be noted that the inflatable chambers or bladders 21 and 22 are of different shapes or configurations, but they can be of the same shape or configuration. Moreover, if desired, they can be different volumes with differing backload effects on switch operation. In some cases, a single bladder may be used. In operation, air from source 17 is introduced by the power nozzle 12 into the interaction chamber or region 11 and, due to some anomaly, will attach to one side or the other, sidewall 13 and flow through outlet 15 and through passageway 20 pressurizing passageway 20 and inflating bladder 22. At the same time, a vortex is formed in interaction chamber 11 on the left side opposite the side that the pressure stream is flowing along. At this time, passageway 19 and bladder 21 are not pressurized. As soon as bladder 22 becomes fully inflated, it backloads the switch via passage 20 and causes the switch to operate, and the fluid flow shifts from flowing along sidewall 13 to flowing along sidewall 14 creating a vortex in the sidewall chamber side 13 and causing the pressurization of passageway 19 and bladder 21. Meanwhile, since the passageway 20 is no longer pressurized, the air in bladder 22 is exhausted through vent 24. As this exhausting of air from bladder 22 takes place, bladder 21 is being inflated by air from the pressurized leg of passageway 19 and inflates and pressurizes bladder 21. Thus, while bladder 21 is being inflated by the pressurization of leg 19, bladder 22 is being deflated by allowing air to flow through the vent 24. It is possible to design the passages so that the jet entrains air from the "deflating" passage. After bladder 21 is fully inflated, it sends a backload signal via passageway 19 to the crossover switch and causes the switching action of the switch to take place to now cause the pressure to flow along sidewall 13 and out and exit into passage 20 thereby pressurizing passage 20 and bladder 22, and the process repeats. Since the interaction region and crossover-type switch is a negative interaction region which is load responsive, when there is a weight on the bladders 21 and/or 22, the dependence on load will cause the massage to feel different each time occupant moves or shifts weight. Furthermore, the frequency of pulsing or switching decreases when the user applies a load on an air bladder which in turn will change the intensity of massaging sensations . Referring now to Figure 2, a pair of backloaded crossover-type fluidic switches having negative interaction regions 30 and 31 with the respective vented split passageway 32, 33 coupled to four bladders Bl, B2, B3 and B4 , respectively, they are connected to a common source of air by tubing or manifold 34 from a common source 35. In this embodiment, the outputs of the bladders are arranged in pairs wherein one airstream is alternately switched from one output passage to the other output passage. Under load, the bladders will be in opposite phase and be of a recognizable pattern. However, when the load is shifted more to one of the bladders than the other one, it takes longer to switch. The inflatable chambers or bladders Bl, B2, B3 and B4 can be arranged so that the pair mates are not located at positions which are regularly associated with each other (see Figure 4). Thus, the invention provides a massaging system having one or more air- inflatable chambers and a fluidic switch alternately connecting the bladders to a source of fluid under pressure by a negative interaction, backloaded fluidic switch which is sensitive to load on the bladders and with the fluidic switch being coupled to the bladder by a pair of vented outlet passages. Referring now to Figure 3, the fluidic switch 36 has a pair of vented outlet passages 37, 38 leading to a pair of inflatable chambers or bladders 39 and 40 which again are shown as having different shapes or configurations. In other words, this showing is to illustrate that the shapes of the bladders is not critical. In this case, the fluidic switch 36 has a pair of control ports 41, 42 which are coupled by a pair of stabilizing feedbacks 43, 44 which are coupled to the output passages 37, 38 in advance of the vents VI, V2. These feedback passages stabilize the shifting and slow the switching operation down. Note that when leg 38 is pressurized, control fluid is passed through passage 44 through the control port 42 to hold the fluid flow on the sidewall opposite thereto. When the inflatable chamber 40 is fully inflated and sends a signal back via passageway 38 to cause the switching of the flow or jet 36, passageway 38 begins to depressurize and the switch operates to cause the pressurization of passageway 37 and bladder 39. Meanwhile, pressure in passageway 38 is decreasing via vent 42 and bladder 40 is deflating, while bladder 39 is inflating. This causes a feedback through passage 43 to maintain this condition until the bladder 39 is fully inflated and the switch 34 senses a backloading signal via passageway 37 to cause a switching action and a repeating of the cycle. Figure 4 illustrates the switching of inflatable chambers with different fluidic switches and shows that the different patterns of inflation and deflection can be adjusted accordingly. In Figure 4, the bladders B5 and B7 are connected to fluidic switch 4-1 and bladders B6 and B8 are connected to switch 4-2. The operation of each switch is as described earlier. In order to achieve a sequential massaging action of a set of four bladders using only one fluidic element, reference is made to Figure 5. In Figure 5, typical fluidic element 50 which alternately switches by backloading from one output to the other is coupled to the pairs of bladders B9, BIO and Bll, B12, respectively. Thus, a pair of bladders is connected to each output passage by one of the bladders. The two bladders in each pair are coupled to each other by a fixed resistance/or disk flow channel 51, 52. If the coupling resistance were a low resistance, then bladders B9, B10 would inflate together and, after switching occurs, the alternate set Bll, B12 would inflate together, coincidentally, as bladders B9 and B10 would deflate together. However, if the resistance 51 or 52 is increased in resistance, bladder 9 will inflate first, and then bladder 10 will inflate later, being delayed by the impedance of resistance. When bladder 9 reaches its maximum, the fluidic element switch is to begin inflating bladder Bll while venting bladders B9 and BIO with bladder B9 deflating first. The deflation of bladder BIO lags bladder B9 because of the coupling resistance. The bladders are placed geometrically on the seat according to their numerical sequence so that the inflation would be experienced by the sequence B9, BIO, Bll, B12. The ways of inflation and subsequent deflation are not perfect because bladders B9 and Bll meet maximum inflation values, whereas bladders BIO and B12 reach less than maximum value because of the resistance induced delaying necessary to provide a sequencing effect between each of the pairs of bladders. This imperfection is not detrimental as the perception of the moving inflation rate is dominant over the perception of the relative inflation magnitude. The strength of the wave action is dependent on the relative magnitude of the inflated versus the deflated pressure rates. Therefore, the relative change of inflation may be improved by substituting for the resistance a fluidic diode rather than a fixed channel resistance as previously described. The fluidic diode has a high resistance when in the inflation direction and a low resistance when in the deflation direction. A vortex chamber diode can be used. As shown in Figures 6A and 6B, a single vent 60 is located between the two output passages 61, 62 of the fluidic switch 63. This single vent 60 has the same area as the two vents used previously combined, and therefore is bigger in diameter and less likely to become clogged with debris and such. In addition, the single vent eliminates the possibility of inconsistent performance in the seat massager due to each vent hole in a single circuit being slightly different in size (due to manufacturing processes, clogging, etc . ) . Figure 7 is a diagrammatic illustration of a vehicle seat incorporating the invention. In this case, the fluidic switches, which may number four sets or more of fluidic switches with each switch being in this embodiment driving or inflating two bladders, which are diagrammatically illustrated as having different shapes and locating different seat portions, and some of the bladders B7 are located in the backrest, some are located in the seat rest, some are located in the wing panels, some are located in the wings on the seat panel. If desired, various switches may be incorporated so as to disable some of the fluidic switches and selected bladders. While the invention has been described in relation to preferred embodiments of the invention, it will be appreciated that other embodiments, adaptations and modifications of the invention will be apparent to those skilled in the art.

Claims: WHAT IS CLAIMED IS: 1. In a massaging system having at least a pair of fluid inflatable bladders and a crossover-type fluidic switch and a pair of passageways alternately connecting said bladders to a source of fluid under pressure, the improvement wherein said crossover-type fluidic switch is a negative pressure interaction region switch which is dependent on the backloading from the bladders. 2. The massaging system defined in Claim 1 wherein said fluid is air and the source is an air pump. 3. The massaging system defined in Claim 2 wherein each bladder is connected to said backloaded switch by a vented passageway. 4. The massaging system defined in Claim 3 wherein in each said passageway a single vent is common to each passageway. 5. The massaging system defined in Claim 1 wherein each fluidic switch includes a pair of control ports and a stabilizing fluid feedback path from said respective passageway to said control port, respectively. 6. The massaging system defined in Claim 1 wherein each inflatable bladder is constituted by at least two chambers connected by a fluid path so that each of said at least two chambers inflate and deflate at different times. 7. The massaging system defined in Claim 6 wherein said fluid path includes a selected one of a fluid resistance and a fluid diode. 8. In a massaging system having at least a pair of fluid-inflatable chambers and a fluidic switch alternately connecting said at least a pair of fluid-inflatable chambers to a source of fluid under pressure, and wherein said fluidic switch is a crossover-type fluid switch having a switching chamber having two side walls in which fluid from said source is switched from one side wall of said switching chamber to the other side of the chamber and is sensitive to backload from the said fluid-inflatable chambers, respectively. 9. In a massaging system having at least a pair of inflatable chambers and a fluidic switch alternately connecting said at least a pair of inflatable chambers to a source of fluid under pressure, wherein the fluidic switch incorporates a switching chamber in which fluid under pressure from a power nozzle is introduced into a chamber in which the side walls diverge from the power nozzle and then converge to a common outlet and fluid flows along one wall or the other and switches back and forth to a pair of outlet passages leading to said at least a pair of fluid-inflatable chambers, and at least one vent coupled to said outlet passages. 10. In a massaging method having at least a pair of fluid-inflatable chambers and a fluidic switch alternately connecting one of said at least a pair of fluid-inflatable chambers to a source of fluid under pressure, the improvement wherein said fluidic switch is a crossover-type fluid switch having a switching chamber having two side walls in which fluid from said source is switched from one side wall of said switching chamber to the other side of the chamber and is made sensitive to backloading from the said fluid-inflatable chambers, respectively. 11. A massaging system having pressurizable chambers at least one of which is a fluid inflatable bladder, a crossover-type fluidic switch and a pair of vented passageways alternately connecting said pressurizable chambers to a source of fluid under pressure, said crossover-type fluidic switch is a negative pressure interaction type switch which is dependent on backloading from said pressurizable chambers.

Inventors: BURNS SEAN T, RAGHU SURYA, SRINATH DHARAPURAM N, STOUFFER RONALD D, BURNS, SEAN, T., RAGHU, SURYA, SRINATH, DHARAPURAM, N., STOUFFER, RONALD, D.
Applicants: BOWLES FLUIDICS CORP, BOWLES FLUIDICS CORPORATION
Application year: 2000
Main classification: A61H1
IPC codes: A61H7, A61H23