Backrest for bariatric chair

Abstract

A chair comprising a base frame; a seat coupled to the base frame and including a seating surface; and a backrest coupled to either the base frame or the seat, including a backrest front surface, the backrest front surface including: an upper backrest front surface including an upper backrest front surface portion; and a lower backrest front surface including a lower backrest front surface portion; wherein the upper backrest front surface portion is disposed, or is positionable to be disposed, forwardly of the lower backrest front surface portion by a horizontal distance of at least 3 inches; and wherein each of the upper backrest front surface portion and the lower backrest front surface portion is disposed in a vertical plane having a vertical plane normal axis which is perpendicular to a normal axis of a plane tangent to the most forwardly disposed front surface of the backrest front surface.

1 . A chair comprising: 
 a base frame;    a seat coupled to the base frame and including a seating surface; and    a backrest coupled to either the base frame or the seat, including a backrest front surface, the backrest front surface including: 
 an upper backrest front surface including an upper backrest front surface portion; and  
 a lower backrest front surface including a lower backrest front surface portion;  
   wherein the upper backrest front surface portion is disposed, or is positionable to be disposed, forwardly of the lower backrest front surface portion by a horizontal distance of at least 3 inches; and    wherein each of the upper backrest front surface portion and the lower backrest front surface portion is disposed in a vertical plane having a vertical plane normal axis which is perpendicular to a normal axis of a plane tangent to the most forwardly disposed front surface of the backrest front surface.    
   
   
       2 . The chair as claimed in  claim 1 , wherein the horizontal distance is between 3 inches and 8 inches.  
   
   
       3 . The chair as claimed in  claim 1 , wherein the horizontal distance is at least 4 inches.  
   
   
       4 . The chair as claimed in  claim 3 , wherein the horizontal distance is between 4 inches and 8 inches.  
   
   
       5 . The chair as claimed in  claim 1 , wherein the seat has a minimum width of at least 18 inches.  
   
   
       6 . The chair as claimed in  claim 5 , wherein the minimum width of the seat is between 18 inches and 38 inches  
   
   
       7 . The chair as claimed in  claim 5 , wherein the seat has a minimum length of at least 20 inches.  
   
   
       8 . The chair as claimed in  claim 7 , wherein the seat has a minimum length of between 16 inches and 24 inches.  
   
   
       9 . The chair as claimed in  claim 1 , wherein an upper backrest front surface portion plane is tangent to the upper backrest front surface portion, and wherein the upper backrest front surface portion plane has a front face which defines or is positionable to define an angle relative to and above a horizontal plane, wherein the angle is at least 85 degrees.  
   
   
       10 . The chair as claimed in  claim 9 , wherein the angle is between 85 degrees and 120 degrees.  
   
   
       11 . The chair as claimed in  claim 9  wherein the angle is 95 degrees.  
   
   
       12 . The chair as claimed in  claim 5 , wherein the backrest has a minimum width of at least 24 inches.  
   
   
       13 . The chair as claimed in  claim 11 , wherein the backrest has a minimum width of between 24 inches and 36 inches.  
   
   
       14 . The chair as claimed in  claim 3 , wherein the backrest has a minimum width of at least 24 inches.  
   
   
       15 . The chair as claimed in  claim 1 , wherein the backrest has a minimum width of at least 24 inches.  
   
   
       16 . The chair as claimed in  claim 15 , wherein the backrest has a minimum width of between 24 inches and 36 inches.  
   
   
       17 . A chair comprising: 
 a base frame;    a seat coupled to the base frame and including a seating surface; and    a backrest coupled to either the base frame or the seat, including a backrest front surface, the backrest front surface including: 
 an upper backrest including an upper backrest front surface having an upper backrest front surface segment, wherein the upper backrest front surface segment has a width of at least 24 inches; and  
 a lower backrest including a lower backrest front surface;  
   wherein each portion of the upper backrest front surface segment is disposed with a respective portion of the lower backrest front surface in a respective vertical plane having a vertical plane normal axis which is perpendicular to a normal axis of a plane tangent to the most forwardly disposed front surface of the backrest front surface; and    wherein each portion of the upper backrest surface segment is also disposed, or is positionable to be disposed, forwardly of the respective portion of the lower backrest front surface by a horizontal distance of at least 3 inches.    
   
   
       18 . The chair as claimed in  claim 17 , wherein the horizontal distance is between 3 inches and 8 inches.  
   
   
       19 . The chair as claimed in  claim 17 , wherein the horizontal distance is at least 4 inches.  
   
   
       20 . The chair as claimed in  claim 19 , wherein the horizontal distance is between 4 inches and 8 inches.  
   
   
       21 . The chair as claimed in  claim 17 , wherein the seat has a minimum width of at least 18 inches.  
   
   
       22 . The chair as claimed in  claim 21 , wherein the seat has a minimum width between 18 inches and 38 inches  
   
   
       23 . The chair as claimed in  claim 21 , wherein the seat has a minimum length of at least 20 inches.  
   
   
       24 . The chair as claimed in  claim 23 , wherein the seat has a minimum length of between 16 inches and 24 inches.  
   
   
       25 . The chair as claimed in  claim 23 , wherein the backrest has a minimum width of at least 6 inches.  
   
   
       26 . The chair as claimed in  claim 25 , wherein the backrest has a minimum width of at least 24 inches.  
   
   
       27 . The chair as claimed in  claim 26 , wherein the backrest has a minimum width of between 24 inches and 38 inches.  
   
   
       28 . The chair as claimed in  claim 25 , wherein the backrest has a minimum length of at least 2 inches.  
   
   
       29 . The chair as claimed in  claim 17 , wherein the backrest has a minimum width of at least 24 inches.  
   
   
       30 . The chair as claimed in  claim 17 , wherein each portion of the upper backrest front surface segment is tangent to a respective upper backrest front surface segment portion plane, and wherein the respective upper backrest front surface segment portion plane has a front face which defines or is positionable to define an angle relative to and above a horizontal plane, wherein the angle is at least 85 degrees.  
   
   
       31 . The chair as claimed in  claim 30 , wherein the angle is between 85 degrees and 120 degrees.  
   
   
       32 . The chair as claimed in  claim 30 , wherein the angle is 95 degrees.  
   
   
       33 . A chair comprising: 
 a base frame;    a seat coupled to the base frame and including a seating surface; and    a backrest coupled to either the base frame or the seat, including a backrest front surface, the backrest front surface including: 
 an upper backrest front surface;  
 a lower backrest front surface; and  
 a merged front surface, wherein an upper backrest front merging surface of the upper backrest front surface extends upwardly from the merged front surface, and a lower backrest front merging surface of the lower backrest front surface extends downwardly from the merged front surface such that the upper backrest front surface merges with the lower backrest front surface at the merged front surface;  
   wherein each of a portion of the upper backrest front merging surface, a portion of the merged front surface, and a portion of the lower backrest front merging surface is disposed in a vertical plane having a vertical plane normal axis which is perpendicular to a normal axis of a plane tangent to the most forwardly disposed front surface of the backrest front surface; and    wherein an upper backrest front merging surface portion plane is tangent to the upper backrest front merging surface portion and a lower backrest front merging surface portion plane is tangent to the lower backrest front merging surface portion, wherein the upper backrest front merging surface portion plane has a front face which defines a first angle relative to and above the lower backrest front merging surface portion plane, wherein the first angle is at least 10 degrees, and    wherein the merged front surface portion is disposed forwardly, or is positionable to be disposed forwardly, of a portion of the lower backrest front surface by a horizontal distance of at least 3 inches, wherein the lower backrest front surface portion is disposed in the vertical plane.    
   
   
       34 . The chair as claimed in  claim 33 , wherein the first angle is between 10 degrees and 60 degrees.  
   
   
       35 . The chair as claimed in  claim 33 , wherein a merged front surface portion plane is tangent to the merged front surface portion, and wherein the merged front surface portion plane has a front face which defines or is positionable to define a second angle relative to and above a horizontal plane, wherein the second angle is at least 80 degrees.  
   
   
       36 . The chair as claimed in  claim 33 , wherein the horizontal distance is between 3 inches and 8 inches.  
   
   
       37 . The chair as claimed in  claim 33 , wherein the horizontal distance is at least 4 inches.  
   
   
       38 . The chair as claimed in  claim 37 , wherein the horizontal distance is between 4 inches and 8 inches.  
   
   
       39 . The chair as claimed in  claim 33 , wherein the seat has a minimum width of at least 18 inches.  
   
   
       40 . The chair as claimed in  claim 39 , wherein the seat has a minimum width of between 18 inches and 38 inches  
   
   
       41 . The chair as claimed in  claim 39 , wherein the seat has a minimum length of at least 20 inches.  
   
   
       42 . The chair as claimed in  claim 41 , wherein the seat has a minimum length of between 16 inches and 24 inches.  
   
   
       43 . The chair as claimed in  claim 34 , wherein the backrest has a minimum width of at least 24 inches.  
   
   
       44 . The chair as claimed in  claim 39 , wherein the backrest has a minimum width of at least 24 inches.  
   
   
       45 . The chair as claimed in  claim 44 , wherein the backrest has a minimum width of between 24 inches and 36 inches.  
   
   
       46 . The chair as claimed in  claim 43 , wherein the backrest has a minimum length of at least 2 inches.  
   
   
       47 . The chair as claimed in  claim 46 , wherein the backrest has a minimum length of at least 6 inches.  
   
   
       48 . The chair as claimed in  claim 33 , wherein the backrest has a minimum width of at least 24 inches.  
   
   
       49 . The chair as claimed in  claim 35 , wherein the second angle is between 80 degrees and 115 degrees.  
   
   
       50 . The chair as claimed in  claim 35 , wherein the second angle is 90 degrees.  
   
   
       51 . The chair as claimed in  claim 33 , wherein the merged front surface portion is disposed, or is positionable to be disposed, above a seating surface portion of the seating surface by a vertical distance of at least 8 inches, wherein the seating surface portion is disposed in the vertical plane and is also disposed in a merged front surface portion plane tangent to the merged front surface portion.  
   
   
       52 . The chair as claimed in  claim 51 , wherein the seat is positioned so as to provide a substantially horizontal seating surface, and wherein the merged front surface portion plane has a front face which defines or is positionable to define a third angle relative to and above a horizontal plane, wherein the third angle is between 70 degrees and 133 degrees.  
   
   
       53 . The chair as claimed in  claim 51 , wherein the distance by which the merged front surface portion is disposed, or is positionable to be disposed, above the seating surface portion of the seating surface is between 8 inches and 18 inches.  
   
   
       54 . The chair as claimed in  claim 51 , wherein the distance by which the merged front surface portion is disposed, or is positionable to be disposed, above the seating surface portion of the seating surface is at least 10 inches.  
   
   
       55 . The chair as claimed in  claim 33 , wherein a two-dimensional space is disposed in the vertical plane and is defined or definable between: (i) the lower backrest front surface, (ii) the seating surface, and (iii) the upper backrest front merging surface portion plane, such that the space has an area of at least 30 inches 2 .  
   
   
       56 . The chair as claimed in  claim 55 , wherein the area of the space is between 30 inches 2  and 100 inches 2 .  
   
   
       57 . The chair as claimed in  claim 55 , wherein the seat is positioned so as to provide a substantially horizontal seating surface, and wherein the upper backrest front merging surface portion plane has a front face which defines or is positionable to define a fourth angle relative to and above a horizontal plane, wherein the fourth angle is between 80 degrees and 153 degrees.  
   
   
       58 . A chair comprising: 
 a base frame;    a seat coupled to the base frame and including a seating surface; and    a backrest coupled to either the base frame or the seat, including a backrest front surface, the backrest front surface including: 
 an upper backrest front surface;  
 a lower backrest front surface; and  
 a merged front surface including a merged front surface segment, wherein an upper backrest front merging surface of the upper backrest front surface extends upwardly from the merged front surface and a lower backrest front merging surface of the lower backrest front surface extends downwardly from the merged front surface, such that the upper backrest front surface merges with the lower backrest front surface at the merged front surface;  
   wherein each portion of the merged front surface segment is disposed with a respective portion of the lower backrest front merging surface and with a respective portion of the upper backrest front merging surface in a respective vertical plane, and wherein the respective vertical plane has a respective vertical plane normal axis which is perpendicular to a normal axis of a plane tangent to the most forwardly disposed front surface of the backrest front surface; and    wherein the respective portion of the upper backrest front merging surface is tangent to a respective upper backrest front merging surface portion plane and the respective portion of the lower backrest front merging surface is tangent to a respective lower backrest front merging surface portion plane, wherein the respective upper backrest front merging surface portion plane has a front face which defines a first angle relative to and above the respective lower backrest front merging surface portion plane, wherein the first angle is at least 10 degrees; and    wherein each portion of the merged front surface segment is disposed forwardly, or is positionable to be disposed forwardly, of a respective portion of the lower backrest front surface by a horizontal distance of at least 3 inches, wherein the respective lower backrest front surface portion is disposed in the respective vertical plane; and    wherein the merged front surface segment has a width of at least 24 inches.    
   
   
       59 . The chair as claimed in  claim 58 , wherein each portion of the merged front surface segment is tangent to a respective merged front surface segment portion plane, and wherein the respective merged front surface segment portion plane has a front face which defines or is positionable to define a second angle relative to and above a horizontal plane, wherein the second angle is greater than 80 degrees.  
   
   
       60 . A chair comprising: 
 a base frame;    a seat coupled to the base frame and including a seating surface; and    a backrest coupled to either the base frame or the seat, including a backrest front surface, the backrest front surface including: 
 an upper backrest front surface;  
 a lower backrest front surface; and  
 a merged front surface, wherein the lower backrest front surface merges with the upper backrest front surface at the merged front surface;  
   wherein a merging surface portion of the upper backrest front surface extends upwardly from a portion of the merged front surface, and a merging surface portion of the lower backrest front surface extends downwardly from the merged front surface portion, and wherein each of the upper backrest front merging surface portion, the merged front surface portion, and the lower backrest front merging surface portion is disposed in a vertical plane having a vertical plane normal axis which is perpendicular to a normal axis of a plane tangent to the most forwardly disposed front surface of the backrest front surface;    wherein an upper backrest front merging surface portion plane is tangent to the upper backrest front surface merging portion and a lower backrest front merging surface portion plane is tangent to the lower backrest front surface merging portion, wherein the upper backrest front merging surface portion plane has a front face which defines a first angle relative to and above the lower backrest front merging surface portion plane, wherein the first angle is at least 10 degrees; and    wherein a merged front surface portion plane is tangent to the merged front surface portion; and    wherein the merged front surface portion is disposed, or is positionable to be disposed, above a seating surface portion of the seating surface by a distance of at least 8 inches, wherein the seating surface portion is disposed in the vertical plane and is also disposed in the merged front surface portion plane.    
   
   
       61 . The chair as claimed in  claim 60 , wherein the seat is positioned so as to provide a substantially horizontal seating surface, and wherein the merged front surface portion plane has a front face which defines or is positionable to define a second angle relative to and above a horizontal plane, wherein the second angle is between 70 degrees and 133 degrees.  
   
   
       62 . A chair comprising: 
 a base frame;    a seat coupled to the base frame and including a seating surface; and    a backrest coupled to either the base frame or the seat, including a backrest front surface, the backrest front surface including: 
 an upper backrest front surface;  
 a lower backrest front surface; and  
 a merged front surface, wherein the lower backrest front surface merges with the upper backrest front surface at the merged front surface, and wherein a merging surface portion of the upper backrest front surface extends upwardly from a portion of the merged front surface, and a merging surface portion of the lower backrest front surface extends downwardly from the merged front surface portion; and  
   wherein each of the upper backrest front merging surface portion, the merged front surface portion, and the lower backrest front merging surface portion is disposed in a vertical plane having a vertical plane normal axis which is perpendicular to a normal axis of a plane tangent to the most forwardly disposed front surface of the backrest front surface; and    wherein an upper backrest front merging surface portion plane is tangent to the upper backrest front merging surface portion and a lower backrest front merging surface portion plane is tangent to the lower backrest front merging surface portion, wherein the upper backrest front merging surface portion plane has a front face which defines a first angle relative to and above the lower backrest front merging surface portion plane, wherein the first angle is at least 10 degrees, and    wherein a two-dimensional space is disposed in the vertical plane and is defined or is definable between: (i) the lower backrest front surface, (ii) the seating surface, and (iii) the upper backrest front merging surface portion plane, such that the space has an area of at least 30 inches 2 .    
   
   
       63 . The chair as claimed in  claim 62 , wherein the seat is positioned so as to provide a substantially horizontal seating surface, and wherein the upper backrest front merging surface portion plane has a front face which defines or is positionable to define a second angle relative to and above a horizontal plane, wherein the second angle is between 80 degrees and 153 degrees.  
   
   
       64 . A chair comprising: 
 a base frame;    a seat coupled to the base frame and including a seating surface; and    a backrest coupled to either the base frame or the seat, including a backrest front surface, the backrest front surface including: 
 an upper backrest front surface;  
 a lower backrest front surface; and  
 a merged front surface including a merged front surface segment, wherein an upper backrest front merging surface of the upper backrest front surface extends upwardly from the merged front surface and a lower backrest front merging surface of the lower backrest front surface extends downwardly from the merged front surface, such that the upper backrest front surface merges with the lower backrest front surface at the merged front surface;  
   wherein each portion of the merged front surface segment is disposed with a respective portion of the lower backrest front merging surface and with a respective portion of the upper backrest front merging surface in a respective vertical plane, wherein the respective vertical plane has a respective vertical plane normal axis which is perpendicular to a normal axis of a plane tangent to the most forwardly disposed front surface of the backrest front surface; and    wherein the respective portion of the upper backrest front merging surface is tangent to a respective upper backrest front surface merging portion plane and the respective portion of the lower backrest front merging surface is tangent to a respective lower backrest front surface merging portion plane; and    wherein the respective upper backrest front merging surface portion plane has a front face which defines a first angle relative to and above the respective lower backrest front merging surface portion plane, wherein the first angle is at least 10 degrees; and    wherein each portion of the merged front surface segment is tangent to a respective merged front surface segment portion plane; and    wherein each portion of the merged front surface segment is disposed, or is positionable to be disposed, above a respective seating surface portion by a distance of at least 8 inches, and wherein the respective seating surface portion is disposed in the respective vertical plane and is also disposed in the respective merged front surface segment portion plane; and    wherein the merged front surface segment has a width of at least 24 inches.    
   
   
       65 . The chair as claimed in  claim 64 , wherein the seat is positioned so as to provide a substantially horizontal seating surface, and wherein the respective merged front surface segment portion plane has a front face which defines or is positionable to define a second angle relative to and above a horizontal plane, wherein the second angle is between 70 degrees and 133 degrees.  
   
   
       66 . The chair as claimed in  claim 64 , 
 wherein each portion of the merged front surface segment is disposed forwardly, or is positionable to be disposed forwardly, of a respective portion of the lower backrest front surface by a horizontal distance of at least 3 inches, wherein the respective portion of the lower backrest front surface is disposed in the respective vertical plane.    
   
   
       67 . The chair as claimed in  claim 64 , 
 wherein a two dimensional space is disposed in the respective vertical plane and is defined or is definable between: (i) the lower backrest front surface, (ii) the seating surface, and (iii) the respective upper backrest front merging surface portion plane, such that the space has an area of at least 30 inches 2 .    
   
   
       68 . A chair comprising: 
 a base frame;    a seat coupled to the base frame and including a seating surface; and    a backrest coupled to either the base frame or the seat, including a backrest front surface, the backrest front surface including: 
 an upper backrest front surface; and  
 a lower backrest front surface;  
 a merged front surface including a merged front surface segment, wherein an upper backrest front merging surface of the upper backrest front surface extends upwardly from the merged front surface and a lower backrest front merging surface of the lower backrest front surface extends downwardly from the merged front surface, such that the upper backrest front surface merges with the lower backrest front surface at the merged front surface;  
   wherein each portion of the merged front surface segment is disposed with a respective portion of the lower backrest front merging surface and with a respective portion of the upper backrest front merging surface in a respective vertical plane, wherein the respective vertical plane has a respective vertical plane normal axis which is perpendicular to a normal axis of a plane tangent to the most forwardly disposed front surface of the backrest front surface; and    wherein the respective portion of the upper backrest front merging surface is tangent to a respective upper backrest front merging surface portion plane and the respective portion of the lower backrest front merging surface is tangent to a respective lower backrest front merging surface portion plane, wherein the respective upper backrest front merging surface portion plane has a front face which defines a first angle relative to and above the respective lower backrest front merging surface portion plane, wherein the first angle is at least 10 degrees; and    wherein, a two-dimensional space is disposed in the respective vertical plane and is defined or is definable between: (i) the lower backrest front surface, (ii) the seating surface, and (iii) the respective upper backrest front merging surface portion plane, such that the space has an area of at least 30 inches 2 , and    wherein the merged front surface segment has a width of at least 24 inches.    
   
   
       69 . The chair as claimed in  claim 68 , wherein the seat is positioned so as to provide a substantially horizontal seating surface and wherein the respective upper backrest front merging surface portion plane has a front face which defines or is positionable to define a second angle relative to and above a horizontal plane, wherein the second angle is between 80 degrees and 153 degrees.