MXPA99001714A - Air pumping system for an automotive seat - Google Patents

Abstract

An adjustable lumbar support system for a vehicle seat (10) includes an inflatable air cell (18), or cells coupled by an air line (140) to a motorized diaphragm pump (22). The outlet valve (76) of the pump is in the form of an umbrella valve (80) which serves not only to seal the pump on the intake strokes, but is of such character to provide the sole seal between the air cell and pump, thereby eliminating the need to have a separate external check valve between the pump and air cell to assure that the air cell does not leak once pressurized.

Description

AIR PUMPING SYSTEM FOR AN AUTOMOBILE SEAT DESCRIPTION OF THE INVENTION This invention relates generally to inflatable power air pumping systems for vehicle seats and, more particularly, to the co valve arrangement used to retain the hermetic cell in the air. Some models of automotive vehicle seats are equipped with a pneumatic lumbar support system that includes the provision of one or more mflable air cells located in the lower region of the backrest and an electric air pump, which, under the control of a Operator switch, supplies low pressure air to the cell. Such systems allow the occupant of a seat to adjust the firmness or contour to suit his personal preference. The air cells may also be provided in other regions of the seat, such as the lateral support areas. It is known that the cell, once inflated, must remain air-tight and not leak, since a change in air pressure inside the cell would produce a corresponding objectionable change in the support provided to the occupant. One source for air loss is the overflow of air from the cell through a non-reversible air pump, often of the reciprocating piston type. A common valve used in the output of such pumps is a fin type valve that has sufficient sealing capacity for the operation of a pump, although by its nature it is not completely leak proof, and therefore, is not capable of to completely seal the air cell against the loss of air through the pump. Consequently, it is a common practice to install an external one-way valve or in-line solenoid valve between the outlet pump and the air cell to prevent overflow through the pump. Such external valves, however, add to the cost and complexity of the system. The present invention overcomes or greatly diminishes the above objections. An adjustable air seat system for an automotive vehicle comprises a seat having seat and back portions and an inflatable air cell or cells, mounted within the seat. A non-reversible low-pressure air pump is provided having an internal working chamber with an air inlet and an air outlet and a reciprocating diaphragm member driven by an electric motor within the chamber between an inlet pulse and a exit impulse. The inlet and outlet openings are adjusted with valves that cooperate to allow air to be drawn into the chamber through the inlet opening in the inlet pulse and exhaust air from the chamber through the outlet in the outlet. exit impulse. The output of the pump communicates with the air cell of the system by means of a conduit. The outlet valve of the pump is in the form of a valve with a lower valve that has an elastic sealing disc and the central rod, the rod drives the sealing disc elastically against a cooperating sealing surface of the pump in superposed relation to the outlet. The valve with lower flange serves to seal the outlet during the entry of air into the working chamber through the entrance in the entrance impulse and, likewise as an airtight seal when the pump is not operative to avoid the reflux of air from the air cell through the pump The valve with lower valve serves both for two functions and eliminates the need for an external voltage valve or solenoid valve normally provided in line between the pump and the air cell, reducing the number of component parts and simplifying the operation of the pumping system BRIEF DESCRIPTION OF THE DRAWINGS These and other objects and advantages will become more readily apparent when considered in connection with the following description and accompanying drawings, wherein: Figure 1 is a perspective view of a vehicle seat that modalizes the invention; Figure 2 is a diagrammatic view of the first currently preferred embodiment of the air system of the invention; Figure 3 is an enlarged cross-sectional view of the system; Figure 4 is a plan view in fragmentary elongated cross section, taken along lines 4-4 of Figure 3; Figure 5 is a fragmentary sectional view taken along lines 5-5 of Figure 4; Figure 6 is an enlarged fragmentary sectional view taken along lines 6-6 of Figure 4; and Figure 7 is a diagrammatic view of another embodiment of a pumping system according to the invention. Referring now more in detail to the drawings, Figure 1 illustrates a self-propelled vehicle seat which has a generally horizontal seating portion 12 and a backrest portion 14 extending generally straight from the seat portion 12 to provide support for an occupant in a sitting position thereon. The seat 10 includes a pump system 16 for adjusting the contour and the firmness of the seat according to the personal preference of the occupant. A flammable air cell 18 of the pumping system is mounted within the seat 10, preferably in the lower lumbar region of the backrest portion 14 and includes an air fitting 20 (Figure 2) that provides an opening within the interior of the cell of air 18. While a system of a single air cell is shown in the drawings for purposes of illustration, it is understood that the invention contemplates within its scope, seating systems that employ multiple air cells in the same or different seat locations (for example, the lumbar region, the support region, etc.). As best shown in Figure 3, the system includes a non-reversible low pressure diaphragm pump 22 for supplying air at low pressure (i.e., less than 5 psi) to the air cell 18. The pump 22 has a rigid cover or pump body 24 preferably made of molded plastic material such as ABS. The body 24 includes a base portion 26 formed with a pair of U-shaped vertical urns 28, 30 having an electric motor 32. A cover 34 is attached to the base 26 and retains the motor 32 in position on the columns 28 , And encloses a compartment 36 adjacent the engine 32 within which a rotating shaft 39 of the engine 32 extends. A rigid manifold portion 38 is housed in < 1 compartment 36 and includes a continuous vertical peripheral wall 40, which is generally cylindrical and has opposing open ends 42, 44, the lower end of which is attached to the base 26 in such a manner as to provide an air tight seal therebetween. An integrally formed partition wall 46 divides the interior of the manifold into an upper working chamber 48 and a lower chamber 50. The lower chamber 50 is further divided by the inlet and outlet cavity walls 52, 54 which extend in relation sealed between the intermediate partition wall 46 at its upper ends and the base portion 26 at its lower ends. The walls 52, 54 therefore isolate the corresponding inlet and outlet cavities 56, 58 from the remainder of the lower chamber 50. An opening 60 is formed in the base portion 26 providing open flow communication between the inlet cavity 56 and the external atmosphere towards the pump body 24. The split 46 of manifold 38 is formed with a plurality of air inlet openings 62 positioned concentrically around a central mounting hole 64 (Figure 4) which provides airflow communication between the entry cavity 56 on one side of the partition wall 46 and the work chamber 48 on the other side. A valve with lower inlet slider 66 is secured within the mounting hole 64 of the partition wall 46 to selectively open and close the inlet openings 62 and thereby control the introduction of air into the working chamber 48. As best shown in Figure 5, valve 66 comprises a one-piece, generally T-shaped member made of an elastic collapsible material such as rubber or plastic, and preferably silicone. The valve 66 has a rod 68 which projects through the central mounting hole 64 and is formed at its end with an elongated worker head or bulb 70. The head 70 is deformable, allowing it to be pulled through the mounting hole 64. At the exit of the orifice 64, the head 70 returns to its elongated state to confront the edge of the hole 64 on the inlet cavity side of the dividing wall 40. An integrally formed annular seal disk 72 is located at the other end of the rod 68 within the chamber 48 and extends radially outwardly in all directions from the rod 68 through the working chamber side of the partition wall. 40 towards a peripheral outer rim radially further outwardly of the inlet openings 62. The length of the rod 68 between the head 70 and the underside of the disc 72 is slightly smaller than the thickness of the dividing wall., so that the rod is placed under constant tension, plastically driving the flexible disk portion 72 releasably against an underlying sealing surface of splice 74 of the partition wall 46, sealing the inlet openings 62. The partition wall 40 has in addition a plurality of outlet openings 76 positioned circumferentially around a central mounting hole 78, like those of the inlet openings 62, to provide airflow communication between the working chamber 48 and the exhaust cavity 54. A valve of the lower outlet chute 80 identical in construction to that of the inlet valve 66 is secured by its rod 82 within the mounting hole 78, so that the elongated head 86 at one end of the rod 82 is projected into the chamber work 48 and the sealing disc 84 at the other end is accommodated in the exhaust cavity 58 (the inverse of the inlet valve 66) . The sealing disc 84 is elastically driven within the releasable sealed coupling against and underlying the sealing surface 88 of the partition wall 46 on the exhaust cavity side of the wall 46, closing the outlet openings 76.

The pump 22 includes a flexible diaphragm 90 (Figure 3) which is mounted on the manifold 38 and forms a movable wall of the working chamber 48. The diaphragm 90 is molded from a soft elastic material, such as natural rubber, and it has a generally planar wall 92 extending continuously through the upper end 44 of the manifold 38. An integrally formed peripheral flange 94 of the diaphragm 90 extends transversely from the wall 92 and surrounds the outer wall or mouth 96 of the manifold 38. The flange 94 has an internal annular rib 98 which intertwines with a corresponding external recess or step 102 of the manifold 38 to secure the diaphragm 90 in position on the manifold 38 and provide an airtight seal between them. The wall 92 of the diaphragm 90 is coupled by a rigid link 104 to an eccentric support lever 106 mounted on the rotating shaft 39 of the motor 32 to drive the wall 92 of the diaphragm 90 with alternating movement towards and from the manifold 38 for defining the input pulses of chamber expansion and diaphragm chamber contraction output 90. One end of the link 104 extends through a central opening 110 of the diaphragm wall 92 and is formed with a pair of axially locking heads 112, 114, which couple the wall 92 on opposite sides of the opening 110 to secure the link 104 axially relative to the diaphragm 90. The other end of the link 104 is formed with a stump 116. The support plate 106 has a portion of cylindrical cylindrical 118 mounted concentrically about the arrow 39 and an axially displaced piston pin 122 projecting from the collar 118 and is received On the stump 116 for coupling the support plate 106 and the link 104. The motor 32 is coupled to the vehicle battery (not shown) by lead wires 124 through an electrical switch 126 (Figure 2). The switch 126 includes a switch body or housing 128 adapted for mounting within the interior compartment of the vehicle in an accessible and convenient location for the operator, such as, for example, the vehicle door panel or the center console. The housing 128 supports a control pad 130 which is deflected by a spring (not shown) in the usual manner to a neutral position or "OFF" to interrupt the energy from the battery to the pump system 16. In the present example, the control pad 130 comprises a rotating element that is capable of being depressed by the operator in order to move the element 130 from the initial neutral position to one of two control positions, the first of which closes the electrical circuit between the battery and the motor, and the second of which operates a purge valve 132 which will be described below. More specifically referring to Figures 3 and 5, which feed the motor 32 by moving the switch element 130 to the first position, the arrow 39 is caused to rotate, which in turn rotates the support plate 106. The eccentric piston pin 122 of the support plate 106 transmits the rotational movement of the support plate 106 in axial reciprocal displacement of the link 104, which in turn moves the wall 92 of the diaphragm 90 axially towards and from, relative to the manifold 38 between the pulses of entrance and exit of air. At each input pulse, the air is drawn into the working chamber 48 by passing the inlet valve 66 through the openings 62. A filter 134 is accommodated within the inlet cavity 56 to release the inlet air from impurities . The sealing disc 84 of the valve with lower outlet outlet 80 remains sealed on the entry pulse to prevent air being drawn into the chamber 48 through the outlet openings 76. At each outlet pulse of the diaphragm 90, the inlet valve 6ß closes causing the air within chamber 48 to compress and exert inlet pressure on outlet valve 80. The increase in air pressure tlexes the peripheral edges of sealing disc 84 of the lower outlet valve outlet 80 outside the coupling sealed with the wall 40, allowing compressed air to exit from the chamber 48 through the air outlet openings 76. A tubular connector 136 projects from the base 26 of the pump body 24 and is in open flow communication with the exit cavity 58 (Figure 3). A vertical cover or shield 138 extends along the connector 136 to protect it from damage during handling and shipping. A flexible air line or duct 140 is coupled at one end to the connector 136 and connected at its opposite end to the inlet fitting of the air cell 18. The air expelled from the pump 22 at each outlet pulse is directed directly into the inside the air cell 18 through the air line 140. The operation of the pump 22 continues until the desired air pressure and therefore a seat contour is achieved (typically on the scale of about 1-3 psi, with pressures of up to 5 psi contemplated). When the desired air cell pressure is obtained, the operator simply releases the control pad 130 which returns by itself under the spring force to the "OFF" position to interrupt the flow of energy to the pump 22. The operation stopping the pump 22 stops the flow of exhaust air which, in turn, causes the lower outlet valve 80 to close, thus sealing the air cell 18 against leakage of air to the pump 22. The quality of the seal that allows the outlet valve 80 to operate without the assistance of an in-line check valve as is customary for sealing the air cell 18, is due in part substantially to its lower valve construction and also to the nature of the contact surfaces of the sealing disc 84 and the underlying base wall 26. The sealing disc 84 is essentially free of defects, so that there are no protuberances, deformations or other imperfections that would provide a different one from a uniform flat sealing surface. The corresponding contact valve seat surface 142 of the base wall 26 (Figure 5) is equally uniform and flat to provide full narrow sealing contact between the disc 84 and the valve seat 142. The valve seat surface 142 of the base wall 26 is polished in a subsequent molding operation to an SPI A-2 finish. This ensures that air does not escape from the air cell 18 back to the pump 22, thus avoiding the need for an in-line check valve. Once the pump 22 has been stopped, further pressurization of the cell 18 can be achieved simply by activating the control pad 130 to operate the pump 22 as before. The pump 22 is advantageously adjusted with an initial motor of small amperage 32 in order to minimize the size, weight and energy requirement of the system 16. An electric pump that extracts approximately 500 milliamperes is preferred, which is considerably lower than that typically used in the industry for lumbar seating systems that draw approximately 2 XL amps. Due to its small size, although the motor 32 may have some difficulty in seating the disc 84 of the outlet valve 80 due to the pressure acting on the disc from the air cell 18. The greatest difficulty is encountered when the pump 22 begins the operation near the end of his exit career. To alleviate the problem and accommodate the small amperage motor 32, it is preferred that a small vent 144 be formed in the pump body 24 which ventilates the working chamber 48 towards the atmosphere. The orifice 144 is extremely small (in the order of approximately 0.012 inches in diameter) and has an extremely small impact on the normal pumping operation of the pump 22. However, during the initial installation, any pressure that accumulates in the chamber work 48 by an incomplete output pulse that is sufficient to break the outlet valve 80 is capable of being vented to the atmosphere through the orifice 144. The diaphragm 90 can then complete a full input pulse followed by an output pulse complete in order to generate sufficient momentum and pressure to seat the outlet valve 80. When it is desired to release the air cell 18 from the air pressure, the operator simply moves the control pad 130 to the second position to operate the purge valve 132. As illustrated in the two embodiments of Figures 1 and 7, the air line 140 has a main section 146 that extends between the pump 22 and the air cell 18, and a branched section 148 of the main section 146 closed at its end by the purge valve 132. In the first embodiment of Figure 1, the de-purge valve comprises a solenoid valve 132a is wired. Switch 126 was started and normally maintained in the fenced position until control pad 130 is moved to the second position. Figure 5 shows an alternative purge valve arrangement comprising a mechanical dump valve 132b such as a Schrader type valve, preferably incorporated within the construction of the switch 126. Turning the control pad 130 to the second position acts to disrupt the axially movable rod of the valve and therefore open the air line to the atmosphere. The release of the control pad 132 allows the rod, which is spring-biased toward the closed position, to be reset to seal the air line. The embodiments described are representative of the presently preferred forms of the invention and are intended to be illustrated instead of definitive thereof. The invention is defined in the claims.

Claims (13)

1. CLAIMS 1. An inflatable power seat support system for a vehicle, characterized in that it comprises: a seat having a generally horizontal seat portion and a backrest portion extending vertically from the seat portion to provide support for an acupante in a sitting position in the same; at least one inflatable air cell mounted within the seat having an opening therein for admitting air in and out of such an air cell; and a diaphragm pump having (a) a pump body with a working chamber, (b) a flexible diaphragm forming a moving wall of such a chamber, (c) air inlet and outlet openings within such a chamber, (d) associated inlet and outlet valves that normally close the inlet and outlet openings although they can be opened to admit and let out air, respectively, from the chamber, (e) a motor coupled to such a diaphragm and operative to drive the diaphragm between an air intake pulse in which air is drawn into the chamber through the air inlet and an exit pulse in which the air inside the chamber is allowed to flow out of the chamber through the air inlet. air outlet, (f) an air line that couples the air outlet of such pump to such opening of the air cell to direct the air that exited from the pump into the air cell, and (g) where the pump outlet valve comprises a valve inlet operational opening to open the air outlet to allow the flow of exhaust air from the pump into such an air cell while closing the outlet during the entry pulse of such a diaphragm and when the engine is not operating so that seal the air cell at all times against the leakage of air to the pump. The system according to claim 1, characterized in that the lower outlet outlet valve is in direct open communication by means of the air line with the interior of the air cell and provides the only valve within the system for sealing of the air cell against leakage through the pump. The system according to claim 1, characterized in that the lower outlet outlet valve comprises a flexible sealing disc portion and an integral flexible stem portion projecting centrally from the sealing disc portion. . The system according to claim 1, characterized in that the valve body includes a valve seat underlying the sealing disc portion of said lower valve, the valve seat comprising a flat region surrounding the exit opening and polish to a surface finish of approximately SPE / SPI A-4. 5. The system in accordance with the claim 1, characterized in that the motor comprises a small electric motor that extracts approximately 0.5 amperes when in operation. The system according to claim 1, characterized in that the pump body includes a vent in continuous open flow communication with the atmosphere. The system according to claim 6, characterized in that the vent hole has a diameter of approximately 0.012 inches. The system according to claim 1, characterized in that the pump body has a valve seat portion in contact with the outlet valve seat disc, the valve seat region being polished to SPI A-2. . The system according to claim 1, characterized in that the air line includes a branched portion in open flow communication with the opening of the air cell. 10. The system in accordance with the claim 9, characterized in that it includes a purge valve coupled to the branched portion and normally closed although movable to an open position for venting the air air cell. 11. The system in accordance with the claim 10, characterized in that it includes a switch operatively coupled to such motor and the purge valve to selectively drive the motor and the purge valve. 12. The system in accordance with the reification 1, characterized in that it includes an eccentric support plate that connects the diaphragm to such motor to effect the pumping action of such a diaphragm in response to the operation of the motor. The system according to claim 1, characterized in that the pump body includes a manifold having a generally cylindrical side wall closed at one end of such diaphragm and joined at its end opposite a base wall of the pump body, the manifold that includes an intermediate transverse partition wall that divides the inside of the manifold inside the working chamber and a lower dormant chamber, the lower chamber that is further divided by air inlet and air outlet division walls , each one isolating an air inlet and a corresponding outlet cavity, the inlet cavity which is in open communication with the atmosphere and which houses an air filter therein, the outlet cavity which is in open flow communication with the air line and housing the sealing disc portion of such an outlet valve.