Vehicle seat assembly having a surface texturing intrusions

In at least one embodiment, the present disclosure provides a vehicle seat assembly comprising a cushion having an “A” surface and a “B” surface, a central portion, and two bolster areas, with each bolster area being adjacent the central portion, with the cushion having a plurality of intrusions extending from the “A” surface towards the “B” surface to form a hardness gradient between at least one of the bolster areas and the central portion of between 5% to 25%, the plurality of intrusions comprising a plurality of pairs of patterns, each pair of patterns comprising a first pattern spaced apart and opposingly and inversely facing a second pattern.

TECHNICAL FIELD

The disclosure relates to a vehicle seat assembly having surface texturing intrusions and method of making the same. More specifically, the present disclosure relates to a vehicle seat assembly having areas configured to have lower hardness than other areas of the seat assembly and methods of making the same.

BACKGROUND

Generally speaking, a typical vehicle seat assembly includes three fundamental components: (a) a frame to support the seat assembly and to mount it to a vehicle; (b) a foam cushion to cover the frame; and (c) trim material to cover the foam cushion and provide a durable surface for contact with a vehicle occupant. Typically, the foam cushion is made from an expandable foam material, such as polyurethane, and is molded to a predetermined shape during a molded process. For example, the predetermined shape of a typical bucket-style seat includes raised front, side, and rear bolster areas and recessed central seating and back sections. The trim material may include any number of materials, such as cloth, polymers, or leather.

SUMMARY

In at least one embodiment according to the disclosure, a vehicle seat assembly includes a cushion having an “A” surface and a “B” surface, a central portion, and two side bolster areas. Each side bolster area is adjacent the central portion, and the central portion of the cushion has a plurality of spaced apart molded intrusions extending from the “A” surface towards the “B” surface to form a hardness gradient of 5% to 25% between at least one of the side bolster areas and the central portion. The plurality of spaced intrusions comprises a plurality of pairs of patterns, with each pair of patterns comprising a first pattern spaced apart and opposingly and inversely facing a second pattern.

In at least another embodiment according to the disclosure, a vehicle seat assembly includes a foam cushion having an “A” surface and a “B” surface, a central portion, a first side bolster area adjacent the central portion, a second side bolster area opposite the first side bolster area and adjacent the central portion, and a front bolster area extending between and connecting the first and second side bolster areas. The central portion of the cushion has a plurality of intrusions extending from the “A” surface towards the “B” surface. The central portion has a first hardness and the first side bolster area having a second hardness at least 5% greater than the first hardness. The plurality of intrusions comprises a plurality of spaced pairs of patterns, with each pair of patterns comprising a first shaped pattern spaced apart and facing a second shaped pattern. Each pattern has a first portion extending generally parallel to each other and the first and second side bolsters in a first direction and a second portion extending in a second direction towards the other pattern.

A method of making a vehicle seat assembly is also provided and includes providing a cushion having an “A” surface, a “B” surface, a central portion, and two side bolster areas. The central portion of the cushion has a plurality of spaced apart intrusions extending from the “A” surface towards the “B” surface to form a hardness gradient of 5% to 25% between at least one of the side bolster areas and the central portion. The plurality of spaced intrusions comprises a plurality of pairs of patterns, with each pair of patterns comprising a first pattern spaced apart and opposingly and inversely facing a second pattern. The method also includes securing the cushion to a frame, and covering the cushion with a trim member.

DETAILED DESCRIPTION

Moreover, except where otherwise expressly indicated, all numerical quantities in this description and in the claims are to be understood as modified by the word “about” in describing the broader scope of this disclosure. Practice within the numerical limits stated is generally preferred. Also, unless expressly stated to the contrary, the description of a group or class of materials by suitable or preferred for a given purpose in connection with the disclosure implies that mixtures of any two or more members of the group or class may be equally suitable or preferred.

Referring now to the figures, where like numerals are used to designate like structure throughout to the drawings, a schematic vehicle seat assembly in accordance with at least one embodiment of the present disclosure is generally shown at10inFIG.1. While the vehicle seat assembly10is illustrated inFIG.1to be a bucket seat assembly, it should be understood that the principles of the present disclosure are applicable to other types of seat assemblies, such as bench, captain, and other types of seat assemblies. It should also be understood that the principles of the present disclosure are applicable to other applications where foam is a component such as back rests, back support pads, arm rests, and head restraints.

As shown inFIG.1, the vehicle seat assembly10includes a seat frame, generally indicated at14having a plurality of mounting brackets (not shown) adapted to operatively secure the seat frame within a vehicle. The seat frame14may be constructed from any material suitable for application within a vehicle seat assembly10, such as aluminum, steel or other metal alloy or a suitable polymer. Further, the seat frame14may be manufactured using a technique commonly known in the art, relative to the type of material employed. By way of example, manufacturing techniques may include stamping, welding, fastening or molding a suitable material to form a seat frame14.

The vehicle seat assembly10comprises a seat back, generally indicated at16, and a lower seat assembly, generally indicated at18. In at least the illustrated embodiment, the seat back16includes a central back support pad20, side bolsters22, and trenches24between the bolsters22and the pad20. In at least the illustrated embodiment, the lower seat assembly18includes a central seating pad26, a plurality of bolsters30and31substantially surrounding at least two opposing sides, and as shown here, three sides, of the central seating pad26, and trenches32between the bolsters30and31and the pad26. Bolsters30are located at opposite sides (i.e., inboard and outboard) of the lower seat assembly18and the bolster31is located at the front of the lower seat assembly18and extends between and connects the front portions of the bolsters30.

The lower seat assembly18further includes a back foam cushion (not shown) and a seat foam cushion generally indicated at34. The seat foam cushion34is conventionally secured to the seat frame14and/or a seat assembly infrastructure (not shown). The foam cushion34may be secured to the seat frame14and/or infrastructure by any method generally known in the art, such as by an adhesive. It should be understood while the foam cushion34is illustrated to be a bucket-seat bottom cushion, the present disclosure can be applicable to any type of seat cushion such as a seat back cushion for a bucket-seat and seat back and bottom cushion for bench seats, as well as other types of seats.

The lower seat assembly18also includes a trim material36adapted to engage the foam cushion34(or cushions) in a covering relationship. The trim material36may include any material commonly known in the art. By way of example, some of the known materials include cloth, leather, or polymers of sufficient quality and thickness for use in seat trim applications. Polymer trim materials may include a flexible closed cell polymer skin material such as polyvinyl, polyvinyl chloride (PVC), thermoplastic olefin (TPO), or thermoplastic urethane (TPU). Additionally, materials for use as trim material36may include a foam backing (not shown, but generally known in the art) which may be manufactured from a variety of polymer foam materials. By way of example, the foam backing may be polyethylene, polypropylene, polyurethane, or a polystyrene foam. Optionally, a mesh or reinforcing material (not shown, but generally known in the art) such as fiberglass or nylon may be applied to the foam backing or back of the trim material36for increasing strength without increasing rigidity.

The seat cushion34has an upper surface38and a lower surface40that is spaced from the upper surface38. The upper surface38of the seat cushion34may be referred to as the “A” surface, and the lower surface40may be referred to as the “B” surface. The seat cushion34also defines an inboard side42and an outboard side44. When an occupant (not shown) is supported on the lower seat assembly18, the weight of the occupant will generally apply an axial load directed generally through the upper surface38of the seat cushion34towards the lower surface40. Although the weight of the occupant will generally induce an axial as well as sheer force in the seat cushion34, those having ordinary skill in the art will recognize that the primary load path of the occupant's weight will be substantially vertical from the upper surface38towards the lower surface40through the seat cushion. However, when the occupant is getting in and out of the vehicle, an increased and substantially sizeable load will typically be placed on the inboard and outboard bolster portions30of the seat cushion34.

In accordance with the present disclosure, a seat cushion34is provided that has one or both side bolsters30having a greater hardness relative to the central seating pad26. In at least one embodiment, the bolster31also has a greater hardness relative to the central seating pad26. To provide the desired hardness gradient, seat cushion34includes a plurality of L-shaped intrusions50extending from the “A” surface38towards the “B” surface40to provide a seat cushion34having varying hardness areas. For instance, the seat cushion34is configured so that one or more of the bolsters30is harder than the central seating pad26. Moreover, the seat cushion34could be configured so that all of the bolsters30and31are harder than the central seating pad26.

In at least one embodiment, the present disclosure enables the modification of the hardness of the foam primarily in the central seating pad26, i.e., areas of typical consumer contact while driving, while keeping the other areas of the seat cushion34, i.e., the bolsters30and31, firmer to enable improved craftmanship and durability performance and provide lateral support to occupants while traveling on curved roadways and during turning. Such a configuration enables the central seating pad26to be softer for improved occupant comfort while allowing the bolster(s)30and/or31to be harder to account for the typically higher loads placed upon the bolster(s)30and/or31upon occupant ingress and egress. Such a configuration can also assist the seat assembly10in achieving H-point specification without significantly modifying seat assembly packaging. In other words, the implementation of intrusions and/or protrusions in accordance with the present disclosure can modify the seat cushion34in such a way that allows the seat assembly10to achieve a desired H-point without having to change the overall shape or size of the cushion34. Additionally, the implementation of can also assist the seat assembly10in achieving a weight reduction and/or cost reduction.

As best shown inFIG.2, the central seating pad26of the seat cushion34includes a plurality of L-shaped intrusions50. The L-shaped intrusions50are arranged in a pattern70over the “A” surface38of the central seating pad26of the seat cushion34. As best shown inFIG.2, in at least one embodiment, the plurality of L-shaped intrusions50are arranged in a pattern of spaced apart rows60. Each row60comprises a plurality of pair62of L-shaped intrusions50. In at least the illustrated embodiment, each pair62of L-shaped intrusions50comprises a first L-shaped intrusion50aand a second L-shaped intrusion50b, wherein the intrusions50aand50bare opposingly and inversely facing each other. It has been found that such an arrangement provides favorable spring action and dampening impact.

In at least one embodiment, each of the rows60of the L-shaped intrusions50are spaced apart 5 to 30 mm, in at least another embodiment 5 to 25 mm, in yet another embodiment 10 to 20 mm, and in still yet another embodiment 10 to 15 mm. It should be understood that while the rows60of L-shaped intrusions50are shown to be straight rows, that any suitable arrangement could be employed.

In at least one embodiment, each of the L-shaped intrusions50aand50bof the pairs62of L-shaped intrusions50are spaced apart 5 to 30 mm, in at least another embodiment 5 to 25 mm, in yet another embodiment 10 to 20 mm, and in still yet another embodiment 10 to 15 mm. In at least one embodiment, due to being arranged opposingly and inversely facing, each pair62of L-shaped intrusions50is arranged in a generally open rectangular or open rectangular shape. In yet another embodiment, each pair62of L-shaped intrusions50is arranged in a generally open square or open square shape. Such an arrangement has been found to provide a relatively even load distribution while avoiding any substantial impression left on the trim cover36.

The pattern70is arranged to provide the desired level of comfort and structural stability. In at least one embodiment the pattern70of the plurality L-shaped intrusions50comprise 10% to 50% of the surface area of the central portion26of the seat pad34, in another embodiment 15% to 45%, and in yet another embodiment 25% to 40%. Such an arrangement has been found to provide a relatively even load distribution while avoiding any substantial impression left on the trim cover36.

In at least one embodiment, each of the L-shaped intrusions50have a length l of 5 to 30 mm, in yet another embodiment of 10 to 20 mm, and in yet another embodiment of 15 to 20 mm. In at least one embodiment, each of the L-shaped intrusions50have a base length b of 10 to 25 mm, in yet another embodiment of 10 to 20 mm, and in yet another embodiment of 15 to 20 mm. Each of the L-shaped intrusions50have a width w of 5 to 20 mm, in yet another embodiment of 5 to 15 mm, and in yet another embodiment of 10 to 20 mm.

In at least one embodiment, each of the L-shaped intrusions50have a length l that is 1 to 1.75 times the base length b, in yet another embodiment of 1.1 to 1.6 times, and in yet another embodiment of 1.25 to 1.5 times. In at least one embodiment, each of the L-shaped intrusions50have a projection length b1that is 50% to 125% the longitudinal length l1, in yet another embodiment 60% to 100%, and in yet another embodiment 70% to 80%.

In at least one embodiment, the L-shaped intrusions50each have a first portion l extending in a first direction and the second portion b1extending in a second direction generally transverse to the first direction. As best shown inFIG.3, a pair62of L-shaped intrusions50have a pair of parallel first portions L and a pair of parallel second portions b1. In at least one embodiment, the first portions L have a length of 10 to 40 mm, in another embodiment 15 to 35 mm, what and in yet another embodiment 18 to 30 mm. In at least one embodiment, the second portions b1have a length of 5 to 20 mm, in another embodiment 7.5 to 17.5 mm, and in yet another embodiment 10 to 15 mm. In an embodiment, the first portions l in each respective pair62of L-shaped intrusions50are spaced from each other 5 to 20 mm, in another embodiment 7.5 to 17.5 mm, and in yet another embodiment 10 to 15 mm. In an embodiment, the second portions b1in each respective pair62of L-shaped intrusions50are spaced from each other 5 to 20 mm, in another embodiment 7.5 to 17.5 mm, and in yet another embodiment 10 to 15 mm.

While the harness gradient can generally be achieved by providing L-shaped intrusions50that extend from the “A” surface38towards the “B” surface40, it is contemplated that the location and/or size of the intrusions can vary as desired. However, in at least one embodiment, the seat cushion34of the present disclosure has a hardness gradient between at least one of the bolsters30and31and the central seating pad26area of the seat cushion34of between 5% to 25%. In other words, at least one of the bolster areas30and31has a hardness that is at least 5% to 25% greater than the hardness of the central seating pad26. In at least certain embodiments, the seat cushion34has a hardness gradient between the bolsters30and the central seating pad26of between 5% to 25%. The hardness can be measured by indentation force deflection (IFD) as measured by ASTM test method No. D3574. In another embodiment, the seat cushion34of the present disclosure has a hardness gradient between at least one of the bolsters30and31and the central seating pad26of the seat cushion34of between 10% and 20%, and in other embodiments of between 12% and 18%.

At least one of the bolsters30,31, preferably both of the side bolsters30, and in certain environments all of the bolsters30and31, have a hardness gradient greater than the hardness of the central seating pad26. In at least one embodiment, the hardness of the central seating pad26of the seat cushion34, as measured by ASTM test method No. D3574, is between 100 and 300 newtons, and in other embodiments between 150 and 250 newtons. In at least another embodiment, the hardness of at least one of the bolsters30and31, as measured by ASTM test method D3574, is between 230 and 350 newtons, and in other embodiments between 250 to 300 newtons. In at least certain embodiments, the hardness of each of the bolsters30and31, as measured by ASTM test method D3574, is between 230 and 350 newtons and in other embodiments between 250 and 300 newtons. In certain embodiments, the hardness range can be 4.5 to 12 kPa and the density range can be 45 to 75 KG/m3.

Furthermore, in at least one embodiment, the seat cushion34of the present disclosure has a hysterisis loss gradient between at least one of the bolsters30and31and the central seating pad26area of the seat cushion34are between 5% to 25%. In other words, at least one bolster area has a hysterisis loss that is at least 5% to 25% less than the hysterisis loss of the central seating pad26. The hysterisis loss can be measured by indentation force deflection (IFD) as measured by ASTM test method No. D3574. In another embodiment, the seat cushion34of the present disclosure has a hysterisis loss gradient between at least one of the bolsters30and the central seating pad26of the seat cushion34of between 10% and 20%, and in other embodiments of between 12% and 18%. In yet another embodiment, the seat cushion34has a hysterisis loss gradient between each of the bolsters30and31and the central seating pad26of the seat cushion34of between 10% and 20%, and in other embodiments of between 12% and 18%.

In at least one embodiment, the front bolster31has a lower hardness gradient relative to the central seating pad26than one or both of the side bolsters30to provide a front bolster31that is softer (primarily for comfort) than at least one of the side bolsters30. In this embodiment, the front bolster has a hardness of 150 to 300 newtons, and in other embodiments of 200 to 250 newtons. In this embodiment, the hardness gradient between the front bolster31and at least one of the central seating pad26is 5% to 20%, and the hardness gradient between the front bolster31and the side bolsters30is 8% to 25%. In at least one other embodiment, the hardness gradient between the front bolster31and the central seating pad26is 8% to 18%, and the hardness gradient between at least one of the front bolster31and the side bolsters30is 10% to 22%.

Referring toFIGS.3and4, schematic perspective and cross-sectional views of an embodiment of a seat cushion34is shown. The central seating pad26has a number of L-shaped intrusions50that extend from the “A” surface38towards the “B” surface40. In at least one embodiment, the L-shaped intrusions50include a generally axial, L-shaped wall72that extends between and connects the “A” surface38with a generally transverse L-shaped intrusions bottom surface74. In at least one embodiment, hole bottom surface48is spaced 1 to 30 mm from the “A” surface38, in at least another embodiment 2 to 20 mm, and in yet another embodiment 7 to 15 mm.

While the L-shaped intrusions50are shown to be a certain shape, it should be understood that the L-shaped intrusions50can vary in size and shape as desired, as long as they maintain a general L-shape. While the location, size and/or shape of the L-shaped intrusions50can vary as desired, in at least one embodiment, the location, size and/or shape of the L-shaped intrusions can be selected based upon a counter response to pressure input of an average measurement of demographic matching consumers in static and dynamic measured clinics in the vehicle. In at least one embodiment, the cushion34can be tuned with L-shaped intrusions50to provide areas of lower hardness in areas of expected higher occupant pressure. Thus, in at least one embodiment, the areas of expected higher occupant pressure will have less L-shaped intrusions50and/or smaller L-shaped intrusions than areas of expected lower occupant pressure.

In at least one embodiment, the L-shaped intrusions50have and a depth or length of 1 to 30 mm, in other embodiments of 5 to 20 mm, and in yet other embodiments of 8 to 15 mm. Moreover, in at least one embodiment, it has been found useful to provide the L-shaped intrusions50with a radius of 1 to 10 mm, and in other embodiments of 2 to 7 mm, to assist in the molding of the seat cushion.

It should be understood that the size, shape, and/or geometry of the L-shaped intrusions50can vary from each other. For instance, one L-shaped intrusions50can be different in size, shape, and/or geometry from another L-shaped intrusions50.

Moreover, while the L-shaped intrusions50can be provided to provide a density and/or hardness gradient to tailor the specific comfort requirements of the seat assembly, the L-shaped intrusions50could also be used to reduce weight of the overall seat assembly, and in particular the foam cushion34. Furthermore, as discussed above, the L-shaped intrusions50can be provided to assist the seat assembly10in achieving a desired H-point and/or cost reduction. Moreover, while the seat assembly10has been described as having bolster portion(s) that are harder than the remainder of the seat assembly, it should be understood that the principles of the present disclosure can be used to manufacture seat assemblies having areas of the seat assemblies that are harder, or at least as hard, as one or more of the bolsters. The L-shaped intrusions50arrangement has been found to provide a relatively even load distribution while avoiding any substantial impression left on the trim cover36. The seat cushion34of the present disclosure can be made by a variety of methods. In at least one embodiment, the seat cushion34is made by molding wherein the L-shaped intrusions are molded into the seat cushion34during the molding operation. In this embodiment, the foam molding tool can be provided with L-shaped protrusions and/or cavities around and/or within which the foam can be molded. It should be understood that other manufacturing means could be used, such as die-cutting the L-shaped intrusions50. In at least one embodiment, it has been found useful to provide molding tools having molding surfaces that result in L-shaped intrusions50having a radius of 4 to 15 mm, and in other embodiments of 6 to 12 mm, to assist in the molding of the seat cushion.

While embodiments of the disclosure have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the disclosure. Moreover, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from spirit and scope of the disclosure.