Patent Publication Number: US-2023150405-A1

Title: Seat surface perforations

Description:
BACKGROUND OF THE INVENTION 
     This invention relates to a seat, and more particularly to a seat having surface perforations. 
     Seats, such as for example vehicle seats, are known that provide for heating, cooling or both via airflow from the seat (heating or cooling or both via convection) toward the person occupying the seat (sometimes referred to as climate controlled seats). In some climate controlled seats, the seat may have a surface (an outer trim layer) formed from leather, with a plurality of perforations formed through the outer trim layer to permit flow of heated and/or cooled air therethrough to heat/cool the occupant. 
     SUMMARY OF THE INVENTION 
     According to an aspect, the invention provides a seat comprising a seat bottom; and a seat back operatively engaging the seat bottom, with at least one of the seat back and the seat bottom having an air impermeable outer trim layer covering at least a portion of an outer surface, the air impermeable outer trim layer including perforations therethrough, wherein the size, spacing or both of the perforations varies based at least in part on a body pressure map, and wherein the perforations are configured to allow airflow therethrough directed toward an occupant of the seat. 
     According to an aspect, the invention provides a seat comprising a seat bottom; and a seat back operatively engaging the seat bottom, with at least one of the seat back and the seat bottom having an air impermeable outer trim layer covering at least a portion of an outer surface, the air impermeable outer trim layer including perforations therethrough, wherein the outer trim layer of at least one of the seat bottom and the seat back comprises a first area, generally associated with a first body pressure of a body pressure map, having a first air permeability resulting from a size, spacing or both of the perforations, and a second area, generally associated with a second body pressure of the body pressure map that is on average lower than the first body pressure, having a second air permeability that is lower than the first air permeability, and wherein the perforations are configured to allow airflow therethrough directed toward an occupant of the seat. 
     According to an aspect, the invention provides a climate controlled seat having a perforation pattern for directional airflow from a seat surface (particularly a surface having an impermeable outer trim layer)—having areas with different air permeabilities (varying sizes, varying spacing of perforations, or both) based at least in part on body pressure map. Airflow may be redirected or increased/decreased to areas of a seat’s surface where it will have a greater and a quicker effect on the human thermal sensation and comfort, thereby improving human thermal comfort for the seat occupant. Registered holes (holes in an outer surface of the air impermeable outer trim layer that do not penetrate completely through the outer trim layer) may be employed to provide for an esthetically pleasing pattern on the seat surface, even though the perforations vary to create the different air permeabilities. 
     Various aspects of this invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiments, when read in light of the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a schematic view of a vehicle seat. 
         FIGS.  2 A and  2 B  are schematic views of a body pressure map on a seat back and seat bottom, respectively. 
         FIGS.  3 A and  3 B  are schematic views of surface perforations on a seat back and seat bottom, respectively. 
         FIGS.  4 A and  4 B  are schematic views of surface perforations on a seat back and seat bottom, respectively. 
         FIGS.  5 A and  5 B  are schematic views of surface perforations on a seat back and seat bottom, respectively. 
         FIGS.  6 A and  6 B  are schematic views of surface perforations on a seat back and seat bottom, respectively. 
         FIGS.  7 A and  7 B  are schematic views of surface perforations on a seat back and seat bottom, respectively. 
         FIGS.  8 A and  8 B  are schematic views of surface perforations on a seat back and seat bottom, respectively. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings, there is illustrated in  FIG.  1    a seat  20 , which may be a vehicle seat, which seat  20  is climate controlled. The seat  20  may have a seat bottom (seat cushion)  30 , a seat back  32  operatively engaging the seat bottom  30 , and a headrest  34  operatively engaging the seat back  32 . Such a climate controlled seat  20  may have a climate control system  22  (e.g., comprising a heating system, a cooling system, a fan and control electronics) that provides heated air, cooled air or both to flow though an outer trim layer (outer surface)  24  of the seat bottom  30 , seat back  32  or both onto the occupant of the seat  20 . A climate control system  22  (shown schematically in  FIG.  1   ) that provides heated and/or cooled air to a seat is known in the art and so will not be discussed in more detail herein. The outer trim layer  24  may be made of an air impermeable material (air impermeable surface), such as for example leather or vinyl. The seat  20  may also include a three-dimensional mesh or spacer fabric layer (air diffuser)  26  (shown schematically in  FIG.  1   ) in the seat bottom  26 , seat back  28  or both that allows the heated/cooled air to flow to various areas of the seat. For a climate controlled seat  20  with air ventilation a three-dimensional mesh or spacer fabric layer (air diffuser)  26  behind the air-impermeable outer trim layer  24  may distribute airflow across/within the seat bottom (seat cushion)  30  and seat back  32 . A three-dimensional mesh or spacer fabric layer in the seat bottom and seat back is known in the art and so will not be discussed in more detail herein. A trim cover foundation  36  (shown schematically in  FIG.  1   ) may be located between the three-dimensional mesh or spacer fabric layers  26 ,  28  and the outer trim layer  24 . A trim cover foundation is known in the art and so will not be discussed in more detail herein. Heated and/or cooled air may be directed throughout the three-dimensional mesh or spacer fabric layers  26 ,  28  and through the trim cover foundation  36  to the outer trim layer  24 . For a seat having an air impermeable surface, then, perforations (discussed below) are needed to allow air to flow onto the occupant of the seat  20  from the seat climate control system  22 . 
     Referring now to  FIGS.  2 A and  2 B , in view of  FIG.  1   , a schematic view of a seat back body pressure map  40  relative to the seat back  32  is illustrated in  FIG.  2 A , and a schematic view of a seat bottom body pressure map  42  relative to the seat bottom  30  is illustrated in  FIG.  2 B . A body pressure map indicates pressures of a seat occupant at various locations on the seat, which may be due in part to a weight distribution of the occupant. As can be seen from this example of body pressure maps  40 ,  42 , the distribution of the weight of a seat occupant is not uniform throughout the seat  20 . The body pressure maps  40 ,  42  may be based on a fiftieth percentile human occupying the seat (as in the example shown)—although other heights, shapes and weights of humans may be employed in producing the body pressure maps  40 ,  42 . Crosshatching shown in  FIGS.  2 A and  2 B  represent one example showing the possible varying pressures on the seat bottom  30  and seat back  32  due to an occupant sitting on the seat. For example, low body pressure areas  44   a  and  44   b  (with  44   b  being areas subjected to a relatively higher body pressure than  44   a ) may be adjacent to trenches  46  in the seat bottom  30  and seat back  32 . Low body pressure areas  44   a ,  44   b  may be farther outboard from vertical and fore-aft trenches  46  in the seat bottom  30  and seat back  32 . Low body pressure areas  44   a ,  44   b  may be generally between a seat occupant’s legs (with some areas between the seat occupant’s legs not being subjected to body pressure, i.e., no body pressure). Low body pressure areas  44   a ,  44   b  may be generally adjacent to an occupant’s upper back and shoulders on the seat back  32 . Continuing with this particular example, medium body pressure areas  48   a  and  48   b  (with  48   b  being areas subjected to a relatively higher body pressure than  48   a ) may be located on the seat bottom  30  adjacent to a seat occupant’s upper thighs and periphery of a buttocks. The medium body pressure areas  48   a ,  48   b  are subjected to greater body pressure than low body pressure areas  44   a ,  44   b . Medium body pressure areas  48   a ,  48   b  may be located on the seat back  32  adjacent to an occupant’s lower back (on either side of an occupant’s spine). Medium body pressure areas  48   a ,  48   b  may be located on the seat back  32  adjacent to an occupant’s shoulder blades. Continuing with this particular example, high body pressure areas  50  may be located on the seat bottom  30  under a seat occupant’s buttocks. The high body pressure areas  50  are subjected to greater body pressure than medium body pressure areas  48   a ,  48   b . High body pressure areas  50  may be located on the seat back  32  adjacent to an occupant’s lower back (on either side of an occupant’s spine). High body pressure areas  50  may be located on the seat back  32  behind an occupant’s shoulder blades. 
     For a climate controlled seat  20  with air ventilation having uniform sizes and spacing of perforations, when an occupant is sitting on the seat  20 , airflow may be more restricted in areas where the three-dimensional mesh or spacer fabric layer  26 ,  28  is significantly compressed by the occupant’s body pressure. Additionally, for a climate controlled seat  20  with air ventilation, when an occupant is sitting on the seat  20 , some perforations (holes through the outer trim layer  24  created to allow for air flow through an impermeable material) may be partially or completely blocked in areas where the outer trim (seat) surface  24  is in contact with the occupant. Such effects of higher body pressure acting on various areas of the seat  20  may reduce the ability of the heated and/or cooled air to flow through the surface  24  in those areas to heat/cool the occupant. Accordingly, a seat occupant may receive limited cooling sensation in areas with greater body pressure pressing against the outer trim (seat) surface  24  when uniform sizes and spacing of perforations are employed. 
     Referring now to  FIGS.  3 A and  3 B , in view of  FIG.  1   -2B, a schematic view of a seat back  32  having perforations  60  through air impermeable portions of its outer trim layer  62  is illustrated in  FIG.  3 A  and a schematic view of a seat bottom  30  having perforations  64  through air impermeable portions of its outer trim layer  66  is illustrated in  FIG.  3 B . The air impermeable portions of the outer trim layers  62 ,  66  may be made of, for example, leather, vinyl or both, or some other air impermeable material. In this example, the seat back  32  has a higher density of perforations  60  (higher air permeability) in a lower back area  68  of the outer trim layer  62  that is adjacent to the area that a seat occupant’s lower back may be disposed when sitting in the seat relative to the density of perforations (lower air permeability) in an upper back area  70  of the outer trim layer  62  that is adjacent to the area that a seat occupant’s lower back may be disposed. In this example, while the perforations  60  may possibly be larger in the upper back area relative to the lower back area, the overall air permeability may be lower due to the total area for airflow through the perforations being less. For the side support areas  72  that are outboard of the lower  68  and upper  70  back areas (outboard of trenches  74 ), these areas  72  may have very few or no perforations. One may note that the body pressure map of  FIG.  2 A  shows an overall higher body pressure in the lower back area than in the upper back area, and lowest body pressure outboard of the trenches  74 . Thus, when the climate control system  22  of the seat  20  is on, with airflow through the perforations  60 , the thermal comfort relative to the occupant’s back may be improved. Also, while in this example the variations of the air permeability through different areas of the seat back  32  (perforation pattern) do not match the body pressure map precisely in all respects, some deviation from the body pressure map may be employed to maintain a certain esthetic look of the seat surface. 
     With regard to  FIG.  3 B , in this example, the seat bottom  30  has a higher density of perforations  76  (higher air permeability) in a seat buttock area  78  of the outer trim layer  66  that is adjacent to the area that a seat occupant’s buttock may be disposed when sitting in the seat relative to the density of perforations (lower air permeability) in a thigh area  80  of the outer trim layer  66  that is adjacent to the area that a seat occupant’s thighs may be disposed. In this example, while the perforations  64  may possibly be larger in the thigh area relative to the buttock area, the overall air permeability may be lower due to the total area for airflow through the perforations being less. For the side support areas  82  that are outboard of the areas  78 ,  80  (outboard of trenches  84 ), these areas  82  may have very few or no perforations. One may note that the body pressure map of  FIG.  2 B  shows an overall higher body pressure in the buttock area  78  than in the thigh area  80 , and lowest body pressure outboard of the trenches  84 . Thus, when the climate control system  22  of the seat  20  is on, with airflow through the perforations  64 , the thermal comfort relative to the occupant’s buttock and legs may be improved. Also, while in this example the variations of the air permeability through different areas of the seat bottom  30  (perforation pattern) do not match the body pressure map precisely in all respects, some deviation from the body pressure map may be employed to maintain a certain esthetic look of the seat surface. 
     In the examples disclosed herein, the seat surface areas outside of body pressure perimeter (outside of where the occupant’s body applies significant pressure to the seat surface) may have a higher airflow restriction (lower air permeability; less density, smaller holes or both) than areas inside the body pressure perimeter. An example of a ratio in airflow restriction may be about 3 to 1 — three times higher airflow restriction outside of body pressure perimeter. Although, other ratios may be employed instead. In this example, air permeability inside of the body pressure perimeter may be about 100 (feet cubed per feet squared per minute (f3/f2/min)) at a pressure of 20 Pascal (Pa), so air permeability outside of body pressure perimeter may have an air permeability of about 30 (f3/f2/min). Also, in the examples disclosed herein, the seat surface along (adjacent to) trenches (e.g., within a width of about one inch from trenches) may have a lower air permeability, for example less than about 30 (f3/f2/min) or possibly no air flow perforations at all since the air flow in and adjacent to the trenches may provide minimal effect of occupant thermal comfort. Similarly, for the examples disclosed herein, the amount of air flowing through the perforations (air permeability) to the areas of the seat that are not in contact with the occupant at all (such as the area between the occupant’s thighs) may be reduced by creating about the same resistance to airflow there than to any other place in the seat (e.g., less than about 30 (f3/f2/min) or possibly no air flow. Additionally, in the examples illustrated herein, one may employ registered holes  88  (i.e., holes in the outer surface that do not extend all of the way through the surface material) to create an appearance of a perforation pattern in order to keep seat surface appearance somewhat more uniform. For example, using registered holes  88  on the seat bottom  30  in an area between an occupant’s thighs. 
       FIGS.  4 A- 8 B , in view of  FIG.  1   -2B, illustrate various examples of arrangements of perforations in seat backs  32  and seat bottoms  30  wherein the size, spacing or both of the perforations  60 ,  64  through the outer trim layers  62 ,  66  varies based at least in part on a body pressure map (such as illustrated in  FIGS.  2 A- 2 B ), and wherein the perforations are configured to allow airflow therethrough directed toward an occupant of the seat  20 . Since these examples are similar to the example illustrated in  FIGS.  3 A- 3 B , and to avoid unnecessary repetition, they will be discussed in less detail than  FIGS.  3 A- 3 B —mostly indicating some differences in the perforation arrangements. Additionally, all of  FIGS.  4 A- 8 B  may employ registered holes in order to provide the desired air flow while achieving a desired esthetic appearance of the seat surface. 
     Referring now to  FIGS.  4 A and  4 B , in view of  FIG.  1   -2B, in this example, the seat back  32  has a higher density of perforations  60  (higher air permeability) in a lower and mid-back area  68  of the outer trim layer  62  that is adjacent to the area that a seat occupant’s lower and mid-back (generally spaced from the spine) may be disposed when sitting in the seat relative to the density of perforations (lower air permeability) in an upper back, hip and spine area  70  of the outer trim layer  62 . For the side support areas  72  that are outboard of the back areas  68  and  70  (e.g., outboard of trenches  74 ), these areas  72  may have very few or no perforations. Also, in this example, the seat bottom  30  has a higher density of perforations  76  (higher air permeability) in a seat buttock and thigh area  78  of the outer trim layer  66  that is adjacent to the area that a seat occupant’s buttock and thighs may be disposed when sitting in the seat relative to the density of perforations (lower air permeability) in an area  80  of the outer trim layer  66  that is the area that is in between and outside of where a seat occupant’s thighs may be disposed and rearward of the buttock. In this example, while the perforations  64  may possibly be larger in the thigh area relative to the buttock area, the overall air permeability may be lower due to the total area for airflow through the perforations being less. For the side support areas  82  that are outboard of the areas  78 ,  80  (outboard of trenches  84 ), these areas  82  may have very few or no perforations. 
     Referring now to  FIGS.  5 A and  5 B , in view of  FIG.  1   -2B, in this example, the seat back  32  has a higher density of perforations  60  (higher air permeability) in a lower and mid-back area  68  of the outer trim layer  62  that is adjacent to the area that a seat occupant’s lower and mid-back (generally spaced from the spine) may be disposed when sitting in the seat relative to the density of perforations (lower air permeability) in an upper back, shoulders, hip and part of a spine area  70  of the outer trim layer  62 . For the side support areas  72  that are outboard of the back areas  68  and  70  (e.g., outboard of trenches  74 ), these areas  72  may have very few or no perforations. Also, in this example, the seat bottom  30  has a higher density of perforations  76  (higher air permeability) in a seat buttock and thigh area  78  of the outer trim layer  66  that is adjacent to the area that a seat occupant’s buttock and thighs may be disposed when sitting in the seat relative to the density of perforations (lower air permeability) in an area  80  of the outer trim layer  66  that is the area that is in between and outside of where a seat occupant’s thighs may be disposed and rearward of the buttock area. In this example, while the perforations  64  may possibly be larger in the thigh area relative to the buttock area, the overall air permeability may be lower due to the total area for airflow through the perforations being less. Also note, in this example, that, while the overall air permeability may be higher overall in the areas just discussed above, patterns in the perforations may be provided for esthetic appeal. Additionally, the seat surface in the shoulder area and trench adjacent areas may employ some or all registered holes  86  since there may be little or no body pressure on this portion of the seat surface. For the side support areas  82  that are outboard of the areas  78 ,  80  (outboard of trenches  84 ), these areas  82  may have very few or no perforations. 
     Referring now to  FIGS.  6 A and  6 B , in view of  FIG.  1   -2B, in this example, the seat back  32  has a higher density of perforations  60  (higher air permeability) in a lower and mid-back area  68  of the outer trim layer  62  that is adjacent to the area that a seat occupant’s lower and mid-back (generally spaced from the spine) may be disposed when sitting in the seat relative to the density of perforations (lower air permeability) in an upper back, shoulders, hip and part of a spine area  70  of the outer trim layer  62 . For the side support areas  72  that are outboard of the back areas  68  and  70  (e.g., outboard of trenches  74 ), these areas  72  may have very few or no perforations. Also, in this example, the seat bottom  30  has a higher density of perforations  76  (higher air permeability) in a seat buttock and thigh area  78  of the outer trim layer  66  that is adjacent to the area that a seat occupant’s buttock and thighs may be disposed when sitting in the seat relative to the density of perforations (lower air permeability) in an area  80  of the outer trim layer  66  that is the area that is in between and outside of where a seat occupant’s thighs may be disposed and rearward of the buttock area. In this example, while the perforations  64  may possibly be larger in the thigh area relative to the buttock area, the overall air permeability may be lower due to the total area for airflow through the perforations being less. Also note, in this example, that, while the overall air permeability may be higher overall in the areas just discussed above, patterns in the perforations may be provided for esthetic appeal. Additionally, the seat surface in the shoulder area and trench adjacent areas may employ some or all registered holes  86  since there may be little or no body pressure on this portion of the seat surface. For the side support areas  82  that are outboard of the areas  78 ,  80  (outboard of trenches  84 ), these areas  82  may have very few or no perforations. 
     Referring now to  FIGS.  7 A and  7 B , in view of  FIG.  1   -2B, in this example, the seat back  32  has a higher density of perforations  60  (higher air permeability) in a lower and mid-back area  68  of the outer trim layer  62  that is adjacent to the area that a seat occupant’s lower and mid-back (generally spaced from the spine) may be disposed when sitting in the seat relative to the density of perforations (lower air permeability) in an upper back, shoulders, hip and part of a spine area  70  of the outer trim layer  62 . For the side support areas  72  that are outboard of the back areas  68  and  70  (e.g., outboard of trenches  74 ), these areas  72  may have very few or no perforations. Also, in this example, the seat bottom  30  has a higher density of perforations  76  (higher air permeability) in a seat buttock and thigh area  78  of the outer trim layer  66  that is adjacent to the area that a seat occupant’s buttock and thighs may be disposed when sitting in the seat relative to the density of perforations (lower air permeability) in an area  80  of the outer trim layer  66  that is the area that is in between and outside of where a seat occupant’s thighs may be disposed and rearward of the buttock area. In this example, while the perforations  64  may possibly be larger in the thigh area relative to the buttock area, the overall air permeability may be lower due to the total area for airflow through the perforations being less. Also note, in this example, that, while the overall air permeability may be higher overall in the areas just discussed above, patterns in the perforations may be provided for esthetic appeal. Additionally, the seat surface in the shoulder area and trench adjacent areas may employ some or all registered holes  86  since there may be little or no body pressure on this portion of the seat surface. For the side support areas  82  that are outboard of the areas  78 ,  80  (outboard of trenches  84 ), these areas  82  may have very few or no perforations. 
     Referring now to  FIGS.  8 A and  8 B , in view of  FIG.  1   -2B, in this example, the seat back  32  has a higher density of perforations  60  (higher air permeability) in a lower and mid-back area  68  of the outer trim layer  62  that is adjacent to the area that a seat occupant’s lower and mid-back (generally spaced from the spine) may be disposed when sitting in the seat relative to the density of perforations (lower air permeability) in an upper back, shoulders, hip and part of a spine area  70  of the outer trim layer  62 . For the side support areas  72  that are outboard of the back areas  68  and  70  (e.g., outboard of trenches  74 ), these areas  72  may have very few or no perforations. Also, in this example, the seat bottom  30  has a higher density of perforations  76  (higher air permeability) in a seat buttock and thigh area  78  of the outer trim layer  66  that is adjacent to the area that a seat occupant’s buttock and thighs may be disposed when sitting in the seat relative to the density of perforations (lower air permeability) in an area  80  of the outer trim layer  66  that is the area that is in between and outside of where a seat occupant’s thighs may be disposed and rearward of the buttock area. In this example, while the perforations  64  may possibly be larger in the thigh area relative to the buttock area, the overall air permeability may be lower due to the total area for airflow through the perforations being less. Also note, in this example, that, while the overall air permeability may be higher overall in the areas just discussed above, patterns in the perforations may be provided for esthetic appeal. Additionally, the seat surface in the shoulder area and trench adjacent areas may employ some or all registered holes  86  since there may be little or no body pressure on this portion of the seat surface. For the side support areas  82  that are outboard of the areas  78 ,  80  (outboard of trenches  84 ), these areas  82  may have very few or no perforations. 
     The principle and mode of operation of this invention have been explained and illustrated in its preferred embodiment. However, it must be understood that this invention may be practiced otherwise than as specifically explained and illustrated without departing from its spirit or scope.