WO2005058638A1

WO2005058638A1 - Device for vibrationally driven operation of pneumatic cushions

Info

Publication number: WO2005058638A1
Application number: PCT/CH2004/000726
Authority: WO
Inventors: Reinhold C. Salgo
Original assignee: Prospective Concepts Ag
Priority date: 2003-12-18
Filing date: 2004-12-09
Publication date: 2005-06-30
Also published as: EP1694530A1

Abstract

An air-tight, flexible cushion (1) in a highly schematic representation is connected to a vibrationally driven air pump (2) by means of a pressure line (4). A suction line (6) connects the air pump (2) to the surrounding atmosphere. Pressure p1 > p0.Im prevails in the cushion (1) and in the pressure line (4) during operation, wherein p0 represents the surrounding atmospheric pressure of the cushion (1). Both pressure regimes p1 and p0 are connected by means of a pressure limiting valve (3). When overpressure ?p = p1-p0 in the cushion (1) exceeds a limit value determined by the settings and embodiment of the pressure limiting valve (3), the pressure limiting valve (3) opens and pressure in the cushion (1) is again reduced to the limit value. The vibrationally driven air pump (2) can be installed in vehicles and planes due to the fact that it operates in the main direction of vibration.

Description

Device for the vibration-driven operation of pneumatic cushions

The present invention relates to a device for the vibration-driven generation and maintenance of an overpressure in pneumatic cushions according to the preamble of claim 1.

Various driving and aircraft seats with at least one air chamber under pressure are known. A seat with pneumatic cushions which are subjected to a constant positive pressure has been disclosed, for example, in the CH patent application CH2003 0175/03. According to the prior art, such pneumatic cushions in vehicles and aircraft are fed with compressed air from a central compressed air store. This compressed air reservoir is usually filled with compressed air using a motor-driven compressor. Since compressed air systems are not standard in passenger vehicles at the moment, the installation of such a system for the operation of fully or semi-pneumatic seats means a considerable additional effort and partially nullifies the weight reduction achieved. In the case of vehicles and airplanes, the ambient pressure of the seats changes considerably depending on the height above sea level and the prevailing cabin pressure. With a higher ambient pressure, the overpressure decreases, in a pillow with constant air pressure and with a falling ambient pressure, the overpressure in the pillow increases; it becomes bloated, becomes harder and in extreme cases threatens to burst. The object of the present invention is to provide a simple, light, low-maintenance and inexpensive device by means of which a constant overpressure can be generated and maintained in pneumatic cushions installed in a means of transport regardless of the prevailing ambient pressure.

The solution to the problem is given in the characterizing part of claim 1 with regard to its essential features, in the following claims with regard to further advantageous developments. The subject matter of the invention is explained in more detail by means of several exemplary embodiments with reference to the attached drawings. Show it

La, b representation of a first embodiment of a device for operating air cushions in cross section as a technical scheme,

2a, b show a second exemplary embodiment of a device for operating air cushions in cross section as a technical diagram,

3a, b representation of a third embodiment of a device for operating air cushions in cross section as a technical scheme,

4 shows a schematic representation of an exemplary embodiment of a pressure relief valve,

5 shows a schematic illustration of a first exemplary embodiment of a vibration-driven air pump in cross section,

6 shows a schematic illustration of a second exemplary embodiment of a vibration-driven air pump in cross section,

7 shows a schematic illustration of a third exemplary embodiment of a vibration-driven air pump in cross section,

Fig. 8 is a schematic representation of a fourth embodiment of a vibration-driven air pump in cross section.

Fig. 1 shows an illustration of a first exemplary embodiment of the inventive concept. In addition to FIGS. La to 3a, a corresponding functional diagram of the respective showed device shown in Figs. lb to 3b. An airtight flexible cushion 1 in a highly schematic representation is connected to a vibration-driven air pump 2 by means of a pressure line 4. An intake line 6 connects the air pump 2 to the surrounding atmosphere. A pressure pl> pO prevails in the cushion 1 and in the pressure line 4, pO denoting the atmospheric ambient pressure of the cushion 1. The two pressure regimes pl and pO are connected by means of a pressure relief valve 3. If the excess pressure Δp = pl-pO in the cushion 1 exceeds a limit value determined by the setting and design of the pressure relief valve 3, the pressure relief valve 3 opens and the pressure in the cushion 1 is reduced again to the limit value. The vibration-driven air pump 2 is installed in the vehicle or aircraft in such a way that it works in the main vibration direction, for a car this would be the vertical, for example. Depending on the intensity of the vibrations, the air pump 2 continuously pumps air into the cushion 1, the excess air quantity, that is to say that which is not required to replace leakage losses or to compensate for an increasing ambient pressure, continuously being released from the cushion again by the pressure limiting valve 3 1 escapes. The pressure relief valve 3 can be integrated in the cushion 1, in the pressure line 4 or already in the air pump 2. The device according to the invention is characterized by its energy autonomy. It can be operated successfully in any system that is subject to a certain minimum level of vibrations and shocks. These conditions are normally met in means of transportation such as vehicles, airplanes and watercraft. Such pneumatic seats equipped according to the invention can be installed without special connections - apart from the usual mechanical fastenings - as energy-autonomous systems and therefore do not require an external energy source such as electrical energy for the operation of an air motor driven by an electric motor. Pump power peaks of the air pump 2 are required, for example, during a descent from the pass of a high road pass. The ambient air pressure rises sharply within a short period of time.

A second exemplary embodiment of the inventive concept is shown schematically in FIG. When using vibration-driven double effect pumps as air pump 2, two separate overpressure regimes can be set up and maintained for each air pump 2. For example, parts of a cushion 1 divided into a plurality of non-communicating air chambers 5 can be kept softer, that is to say under less overpressure Δp = pl — pO, than others which are harder at a higher overpressure Δp = p2-p0. The different overpressures Δp are achieved by means of different or differently set pressure relief valves 3. It is also conceivable and in accordance with the invention to use several air pumps 2 per pneumatic seat, either to ensure the necessary pumping capacity or to enable other different overpressure regimes. A double effect pump can of course also be used for a single overpressure regime if the two pressure outputs of the air pump 2 are connected in parallel.

3 shows a third exemplary embodiment of a device according to the invention in cross section. The vibration-driven air pump 2 is mounted inside the cushion 1. A pressure line 4 is not required, but the air pump 2 must be connected to the surrounding atmosphere by means of an intake line 6.

Fig. 4 shows an embodiment for a pressure relief valve 3 with adjustable opening pressure. The valve seat 7 is, for example, rotationally symmetrical to the axis A. An air duct 8 connects the overpressure regime with a pressure pl to the ambient pressure regime with the pressure pO. The air channel 8 widens coming from the cushion 1 to a conical funnel. The air duct 8 is sealed airtight by a valve body, a ball 9, pressed into this funnel. For this purpose, the ball 9 is pressed into the funnel with the aid of a spring element 10, the pretensioning of the spring element 10 being able to be varied, for example, by means of an adjusting screw 11. If the ball is 9 made of relatively heavy material, for example metal, and if the pressure relief valve 3, as shown, is installed vertically with the funnel upwards, the weight of the ball 9 is added to the spring force of the spring element 10. The higher the contact pressure with which the spring element 10 presses the ball 9 into the funnel, the higher the resulting overpressure Δp in the cushion 1. The pressure relief valve 3 shown is a spring and weight-loaded check valve.

5 shows a first preferred exemplary embodiment of a vibration-driven air pump 2 in cross section. An air pump 2 only needs to be able to deliver relatively small pressures of 50-300 hPa for use in a device according to the invention. With a suitable dimensioning of the air pump 2, however, it can also generate significantly higher overpressures. The pumping power required strongly depends on the particular area of application of the device. The actual maximum air requirement, depending on the volume of the cushion 1 and the pressure fluctuations in the ambient pressure pO, must be covered by the pump power, which depends on the dimensioning of the air pump 2 and the kinetic energy quantity supplied by vibrations. On a ship, for example, the barometric fresh pressure fluctuations caused by changes in height are negligible, so the air requirement is small. The air pump 2 only has to compensate for leakage losses of the cushion 1 and compensate for meteorological pressure increases. In contrast, the above-mentioned descent from the top of a high Alpine pass, at which the ambient pressure increases rapidly in a short time, requires a significantly higher pump output. The first exemplary embodiment of an air pump 2 shown is a double-effect inertial diaphragm pump. The principle of vibration-driven air pumps 2 is fundamentally based on the conversion of kinetic energy into potential energy. For example, the short-term, large vertical accelerations that a road vehicle experiences when driving on a road are converted into the pressure energy of the generated compressed air and into Spring energy of the spring holding the piston mass in an equilibrium position is transferred. The potential energy of the tensioned spring is used to return the air pump 2 to its neutral equilibrium position at any time. The pressure energy is used for the compressed air supply to the cushion 1.

The air pump 2 shown consists of a two-part sheet metal housing 12 consisting of a lower shell 13 and an upper shell 14. Between the two shells 13, 14, an elastic membrane 15 is clamped, for example by screwing the shells 13, 14. The membrane 15 separates the through the two shells 13, 14 formed cavity 16 airtight into an upper and lower chamber 17, 18. A mass 19 is attached centrally to the membrane 15. The mass 19 can consist, for example, of two metal parts which clamp the membrane 15 between them by means of a screw connection, or the masses are glued to the membrane 15 at the top and bottom. The mass 19 is held in a neutral equilibrium position when the air pump 2 is mounted vertically by means of a spring 23 attached to the upper shell 14. This spring 23 is unnecessary if the vertical component of the deflection of the mass 19 is essentially zero, that is to say the air pump 2 is mounted horizontally and uses horizontal vibrations. If the air pump 2 is accelerated upwards, for example by driving on a bump, the mass 19 moves downward due to its inertia relative to the sheet metal housing 12, thereby reducing the volume of the lower chamber 18, which in turn results in an increase in pressure in this chamber 18. This short-term pressure increase can be converted into a directional pump flow by means of at least two check valves 20. When the pressure in the chamber 18 increases, the check valve 20 in the suction line β is closed, and the check valve 20 in the pressure line 4 to the cushion 1 is opened, provided the pressure difference between chamber 18 and cushion 1, or the deflection of the mass 19 and so that the volume reduction of the chamber 18 is sufficiently large to allow the pressure in the chamber 18 to be greater than the pressure pl in the cushion 1. When the mass 19 swings back, the volume in chamber 18 is reduced, the pressure in it drops, the check valve 20 in the pressure line 4 closes and the check valve 20 in the suction line 6 opens and permits pressure equalization between the chamber 18 and the surrounding one The atmosphere. In the double-effective air pump 2, each cycle of the air pump 2 or each deflection of the mass 19 is turned into an operating cycle with air compression by an analog upper chamber 17, pumping and sucking alternately in the chambers 17, 18. When sucking into the lower chamber 18, the upper chamber 17 compresses or pumps, and vice versa. It is contained in the inventive concept that an air pump 2 can have only one chamber 17, 18, the air pump 2 only pumping effectively during half the oscillation period, while it draws in air during the other half of the oscillation period. The openings of the check valves 20 to the chambers 17, 18 are arranged in such a way that they are not closed by the membrane 15 or the mass 19 even when the mass 19 is deflected to a maximum. They are located, for example, in the bottom of the two shells 13, 14 A buffer 21 made of elastic material can also be attached to the bottom of the two shells 13, 14, which prevents the mass 19 from striking the sheet metal housing 12 without braking at high accelerations. 6 shows a second exemplary embodiment of a vibration-driven air pump 2 in cross section. It is a piston pump. The mass 19 has a cylindrical shape and acts as a piston in a tubular cylinder 22. The mass 19 is held in a neutral equilibrium position by two springs 23, the spring 23 moving the mass 19 downwards being eliminated with the air pump 2 installed vertically, since the weight of the mass 19 can take over this function. Tension springs are preferably used as springs 23; in principle, compression springs can also be selected. The upper and lower chambers 17, 18 are analogous to the first exemplary embodiment in FIG. 5 by means of an arrangement of suction line 6 with check valve 20 and pressure line 4 with check valve 20 with the cushion 1 and the surrounding one Atmosphere connected. Again, it is possible to use only the lower chamber 18 for air pumping and to keep the upper chamber 17 in equilibrium with the ambient pressure. FIG. 7 schematically shows a third exemplary embodiment of a vibration-driven air pump 2 in cross section. This air pump 2 is double-acting. In contrast to the preceding examples, the mass 19 is not inside the cavity 16, but is located outside the same, and the inertial energy is transmitted to two pistons 24 in a boxer arrangement by means of a lever 25 and two push rods 27. The lever 25 is fastened to a pump housing 26 so as to be pivotable about a horizontal axis by means of a swivel joint 28. An adjustable torsion spring 29, for example a spiral spring, keeps the mass 19 in a neutral equilibrium position when gravitationally accelerated. If the main direction of the vibrations or oscillations to be used does not run in the direction of gravitational acceleration, that is to say not essentially in the vertical direction, the equilibrium position of the mass 19 can be determined by means of a second adjustable torsion spring 29 with the opposite direction of rotation. When the mass 19 is deflected from the neutral equilibrium position, the pistons 24 move in hollow cylinders 30 closed on one side and thereby change the volumes of a first chamber 31 and a second chamber 32. Each chamber 31, 32 is connected to a line 33 with an inlet-outlet combination 34 connected. The inlet-outlet combination 34 is shown symbolically in FIG. 7 and its detailed design is illustrated by means of an enlarged magnifying glass. The suction line 6 opens via a check valve 20 into the line 33, which on the one hand leads into one of the chambers 31, 32 and on the other hand is connected via a second check valve 20 to the pressure line 4 leading to the cushion 1. The pressure lines 4 of the two inlet / outlet combinations 34 can be connected to one another and supplied together to the same pressure regime, or, as shown in FIG. 2, they can feed two separate pressure regimes separately with compressed air. The mass 19 can be limited in its deflection by means of two buffers 21. 8 shows a fourth exemplary embodiment of a vibration-driven air pump 2 in cross section. The first and second chambers 31, 32 of the air pump 2 are formed by two hollow air-filled balls 36, made of elastic, flexible material, for example of rubberized fabric or rubber. The balls 36 are fastened to the pump housing 26 on the sides facing away from one another. Each line 33 connects the chambers 31, 32 to an inlet-outlet combination 34. The mass 19 transmits its movement relative to the air pump 2 analogously to the third exemplary embodiment in FIG. 7 by means of a lever 25 to the two chambers 31, 32. The lever 25 is attached to the pump housing 26 by means of a flexible joint 35. However, the lever 25, for example as shown in FIG. 7, can be connected to the pump housing 26 by means of a swivel joint in a spring-loaded manner in both directions of rotation. A connecting piece 37, which is rotatably fastened to the end of the lever 25 opposite the mass 19, creates the connection between the lever 25 and the balls 36. This embodiment of an air pump 2 is not only double-acting, but simultaneously double-acting, ie in the two chambers 31, 32, air is compressed or air is sucked in at the same time. Therefore, only one inlet-outlet combination 34 is necessary. When the mass 19 is in a neutral equilibrium position, the two balls 36 have a maximum volume of the chambers 31, 32. With each deflection of the mass 19 from its neutral equilibrium position, both chambers 31, 32 pump air into the line 33. One ball 36 is drawn out in length and the other ball 36 is compressed. With both balls 36, the deformation leads to a volume reduction and thus to a compression of the amount of air contained in the chambers 31, 32. It is also conceivable to use cylindrical elastic bellows instead of the balls 36, which leads to a comparable air pump 2, such as that shown in FIG. 7. The lever 25 can have any shape.

Claims

claims

1. Device for generating and maintaining an overpressure Δp constant in relation to the ambient air pressure in at least one airtight cushion (1), which is part of a pneumatic seat located in a means of transport, with an air pump (2), characterized in that the air pump (2) is vibration-driven, a mass (19) is integrated in the air pump (2), the mass inertia of which is used to compress air when the air pump (2) accelerates in alternating directions, and at least one pressure limiting valve (3) is present, which controls the excess pressure in the cushion (1) is limited to a determinable value and the excess compressed air can escape.

2. Device according to claim 1, characterized in that more than one vibration-driven air pump (2) is present.

3. Device according to one of the claims 1 to 2, characterized in that at least one double-acting vibration-driven air pump (2) is present.

4. Device according to claim 3, characterized in that a double-acting vibration-driven air pump (2) simultaneously feeds two different pressure regimes, where p2> pl> pO and where pO denotes the operating pressure.

5. Device according to one of the claims 1 to 4, characterized in that at least one vibration-driven air pump (2) is integrated in the interior of a cushion (1).

6. Device according to one of the claims 1 to 5, characterized in that the pressure relief valve (3) is adjustable.

7. Device according to one of claims 1 to 6, characterized in that the air pump (2) is mounted so that the direction of vibration of the mass (19) corresponds to the main direction of the vibrations acting on the air pump (2).

8. Device according to one of the claims 1 to 7, characterized in that the vibration-driven air pump (2) can generate overpressures of 50 to 300 hPa.

9. Device according to one of the claims 1 to 8, characterized in that the pressure relief valve (3) can limit the excess pressure in the range from 50 to 300 hPa.

10. Device according to one of the claims 1 to 9, characterized in that the opening pressure of the pressure relief valve (3) can be adjusted manually.

11. Vibration-driven air pump (2), in particular for operating a pneumatic cushion (1) according to patent claims 1 to 10, characterized in that a mass (19) which is movably mounted with respect to one direction is present on the pump housing (26), this mass (19) assumes a neutral equilibrium position in the unaccelerated state, further with at least one airtight chamber (17, 18, 31, 32), which via an inlet / outlet combination (34) with a pressure line (4) and an intake line (6) is connected, the mass (19) deflected from the neutral equilibrium position changing the volume of the at least one chamber (17, 18, 31, 32).

12. Vibration-driven air pump (2) according to claim 11, characterized in that the wall of the chamber (17, 18) are partially formed by the mass (19).

13. Vibration-driven air pump (2) according to claim 12, characterized in that the air pump (2) is designed as a diaphragm pump, the mass (19) being integrated centrally in the elastic diaphragm (15) and the mass (19) by means of a spring (23) is kept in the neutral equilibrium position.

14. Vibration-driven air pump (2) according to claim 12, characterized in that the mass (19) is designed as a cylindrical piston of a piston pump, the mass (19) being held in the neutral equilibrium position by means of at least one spring (23).

15. Vibration-driven air pump (2) according to claim 11, characterized in that the mass (19) is attached to a lever (25), the deflection of the mass (19) by means of this lever (25) to at least one chamber (31, 32) is transmitted and leads to their volume change.

16. A vibration-driven air pump (2) according to claim 15, characterized in that an end of the lever (25) opposite the mass (19) is connected to at least one piston (24) by means of at least one pivotably mounted push rod (27), the piston (24) together with a hollow cylinder (22) forms a chamber (31, 32).

17. Vibration-driven air pump (2) according to claim 15, characterized in that the mass (19) opposite end of the lever (25) by means of a pivotally mounted connecting piece (37) non-positively connected to at least one elastic flexible hollow ball (36) , the inside of this ball (36) being the Chamber (31, 32) forms, and the ball (36) loses the spherical shape upon deflection of the mass (19) from the neutral equilibrium position and is elastically deformed into an ellipsoid with a reduced volume of the chamber (31, 32).

18. Vibration-driven air pump (2) according to one of the claims 15 to 17, characterized in that the lever (25) is pivotally attached to the pump housing (26) by means of a rotary bearing (28), the mass (19) by means of at least one Torsion spring (29) and the weight of the mass (19) can assume the neutral equilibrium position.

19. Vibration-driven air pump (2) according to one of the claims 15 to 17, characterized in that the lever (25) is pivotally attached to the pump housing (26) by means of a flexible joint (35), the mass (19) by means of this flexible joint (35) and the weight of the mass (19) can assume the neutral equilibrium position.

20. Vibration-driven air pump (2) according to one of the claims 11 to 19, characterized in that it can generate overpressures up to 3000 hPa.

21. Pressure relief valve (3) in particular for operating a pneumatic cushion (1) according to claims 1 to 10, characterized in that the valve seat (7) is designed as a funnel, a ball (9) is also present as a valve body, and this ball (9) is pressed against the valve seat (7) by means of adjustable spring force, and this pressure limiting valve (3) can further limit pressures to 50 to a maximum of 300 hPa.