BACKGROUND

The present invention relates to suspension fabric seating and more particularly, to a cooling system for suspension fabric seating.

Suspension or suspended fabrics have come into common use as an alternative to hard surfaces and foam padded surfaces for seating. Such suspension fabric seating surfaces can provide the comfort of foam padded surfaces in a weight similar to hard plastic seating and at relatively low cost. Advantageously, suspension fabric seating provides enhanced comfort using a preset tension in the suspension fabric that is adjustable for reaction force for comfort needs, provides tunable pixel element spacing and adjustable pixelated face sizes and shapes.

Vehicle seating, however, is typically of the foam-padded type, and is designed for comfort. Such foam-padded seating includes a steel structure and stamped components that are welded together to form a seating structure subassembly. A steel suspension layer that is below the occupant is added to bridge the distance between seat structure beams. The steel suspension offers some hammocking between structure pillars in the seat structure to enhance comfort characteristics. The foam padding, such as polyurethane (PU) is covers the steel structure and suspension, and offers force vs. deflection compliance during use for occupant comfort. In a typical configuration, the foam layer is covered with a trim cover that may include leather, vinyl, and/or polyester textile fabric, a lofted fabric breathable layer and felt or a bonded layer to prevent wrinkling. These layers are used generally to manage comfort requirements as well as G-forces during a crash event.

Foam, however, has disadvantages in that although it provides comfort, it is difficult to cool. Current automotive seat cooling designs use a blower motor to generate a vacuum pulling air through a manifold housed within the foam seating pad. The foam is not porous so voided channels are designed within the foam that funnel air into a spacer fabric to draw the air into the blower motor fan. Moisture from the occupant is pulled away from the body into the manifold causing moisture to evaporate, to provide a cooling sensation.

Conventional seat designs use seat covers or trim covers manufactured from leather or vinyl for aesthetics. These trim covers are inherently non-porous. Small holes are made in the trim cover surface to create air paths to draw air and moisture away from the occupant to provide the cooling function. The pierced holes can be an issue with style-focused designers because they reduce the aesthetics and reduce trim cover robustness. The holes in the trim covers are pierced as small as possible to limit the differences in appearance from cooled front row seats, to, typically, non-cooled second and third row seating.

The smaller holes also reduce air flow and require a larger, more powerful vacuum blower to achieve specified cooling levels and time to cool. These larger, more powerful blowers thus draw increased electrical current, which is a limiting factor when designing vehicle electrical systems, including alternators. This adversely affects engine horsepower available for the vehicle powertrain which ultimately affects vehicle mileage ratings. Electrical current draw is especially important when all electric powertrains are used, which rely solely on battery charge. As such, electrical current management is thus an important goal in automotive design.

Seat cooling systems are also quite complex. In addition to air/vacuum blowers, as noted above, voids in foam padding and holes in trim covers are required in order to pull air from the seat. Manifolds and spacer fabrics to protect the manifolds are needed to pull air from the foam voids to the blower. The manifolds may be formed as part of the foam void system, but may also be separate components that connect to the voids and the blower. Performance issues can occur with current cooling manifolds when the foam and/or manifolds are compressed, limiting air flow. Larger seat occupants can compress the foam and/or manifolds which can result in reduced or even no air flow for cooling.

Cooling systems also require physical space to house the manifolds for cooling function. The blower motor size is also relatively large due to the resistance to air flow. All of these factor lead to increased space needed for the system components and also add thickness to the overall seat.

Moreover, in electric vehicles that are power by batteries, the batteries are housed in a battery tray covering the vehicle floor panel. Battery trays require space (primarily height) which results in raised roof lines, or reduced thickness in the seat construction. Mileage targets are impacted by raised roof lines which increase vehicle drag and decrease vehicle aerodynamics.

Cooling systems are also known for suspension seating systems. Current suspension seating cooling system use the suspension fabric porosity to reduce the resistance to heat transfer. This enables the occupant to attain the surrounding environment temperature and humidity levels to provide cooling and body temperature regulation. One drawback to such cooling systems is that the porosity required for forced air and ambient air to cool the occupant requires holes in the suspension fabric, which has an impact on the aesthetic design of the seats.

Accordingly, there is a need for a suspension seat cooling system that has reduced complexity. Desirably, such as system uses a low profile design that includes a reduction in the size of the components of the cooling system to conserve space in the vehicle. More desirably still, such a system has increased electrical efficiency to reduce the electrical requirements for the cooling system. Still more desirably, such a system eliminates the need for the spacer fabric currently needed for foam seats.

SUMMARY

In one aspect a seat and a cooling system therefor are disclosed. The seat includes a porous seat surface and an air spacer disposed on a side of the suspension seat surface. The air spacer defines an air channel. A substantially air impermeable barrier having an opening therein is in communication with the air channel and a blower is configured to draw air through the seat surface and from the air channel. The air drawn from around an occupant on the seat surface draws moisture from the occupant, causing moisture to evaporate, to provide a cooling sensation. In an embodiment, the drawn air flows parallel to the occupant's skin and as close as possible to the occupant's skin throughout the air travel, from the seat perimeter to the vacuum blower. In an embodiment the air channel or manifold is thin is close to the seat surface to maximize turbulent air flow at the occupant's skin to achieve high moisture evaporation rates.

In an embodiment, the seat surface, the air spacer and the barrier are sealed along a periphery thereof. In some embodiments, the barrier is formed as part of the air spacer. The air spacer and barrier can be formed as a polymeric member. The polymeric member can have a series of projections, and spaces between the projections define, at least in part, the air channel.

In other embodiments, the barrier is a member separate from the air spacer. In an embodiment, the air spacer is formed from polymeric filaments. In an embodiment, the air space is defined, in part, by the porous seat surface. The porous seat surface can be formed from, for example, a woven fabric material. A fabric can be woven from warp and weft fibers and the barrier can be mounted at selected locations to one of the warp and the weft fibers.

In an embodiment, the blower is mounted about the opening in the barrier. An intake spacer can be mounted to the barrier to space the blower from the barrier. A second barrier can be positioned on the intake spacer between the blower and the blower spacer.

In embodiments, the air spacer and barrier are configured to move with the seat surface when the seat surface is loaded, and the blower is mounted to move with the seat surface, air spacer and barrier.

In another aspect, a seat includes a porous seat surface, a substantially air impermeable barrier having an opening therein and an air space between the seat surface and the barrier. A vacuum source is in communication with the air space, such that air is drawn through the seat surface into the air space and from the air space by the vacuum source. The air is drawn through the seat surface and away from an occupant on the seat surface to effect cooling of the occupant.

The seat can include a voided material in the air space. In an embodiment, the impermeable barrier and the voided material are formed as a unitary member. In embodiments, the vacuum source is a blower, and the blower is mounted to move with the seat surface as the seat surface is loaded. The mount can be, for example, a suspension mount.

These and other features and advantages of the present device will be apparent from the following description, taken in conjunction with the accompanying sheets of drawings, and in conjunction with the appended claims.

