Seat cushion

Claim 2

A seat cushion, comprising: a first layer having a front edge, a rear edge, a bottom surface and an upper surface; a second layer having a front edge, a rear edge, a bottom surface and an upper surface with the bottom surface of said second layer supported by the upper surface of said first layer; a third layer having a front edge, a rear edge, a bottom surface and an upper surface with at least a portion of the bottom surface of said third layer supported by the upper surface of said second layer; said first, second and third layers being formed of a foam material, and said first layer being formed of a foam material which has different IFD values than said second layer and said second layer being formed of a foam material which has different IFD values than said third layer and said first layer being formed of a material which is different than that of said second and third layers; said first, second and third layers being dimensioned and arranged such that an upper surface of said seat cushion slopes downwardly with respect to said bottom surface of said from the front of said seat cushion to the rear of said seat cushion with a range of 41/2 to 51/2 degrees so as to define a wedge-shaped seat cushion; and said first, second and third layers being dimensioned and arranged such that the upper surface of said sat cushion defines a pair of depressions that each originate at the front edge of said seat cushion and extend rearwardly toward the rear edge of said cushion, said depressions being laterally spaced from one another between two side edges of said seat cushion.

Claim 3

A seat cushion as recited in claim 1, wherein the upper surface of said third layer is convoluted.

Claim 4

A seat cushion as recited in claim 1, wherein the upper surface of said third layer is convoluted and includes a plurality of protrusions having integral corners and a plurality of protrusions having integral corners and a plurality of valleys positioned between said protrusions.

Claim 5

A seat cushion as recited in claim 1, wherein the first layer has a compression modulus value between 2.4 and 2.6, said second layer has a compression modulus value between 1.9 and 2.1, and said third layer has a compression modulus value between 2.7 and 3.3.

Claim 6

A seat cushion as recited in claim 1, wherein said second layer has recesses formed therein which result in said depressions in the upper surface of said seat cushions and said recesses have a maximum depth between 3/4 to 7/8 inches and extend rearwardly from the front end of said seat cushion for about 35 to 45% of the front to rear length of said second layer.

Claim 7

A seat cushion as recited in claim 1, wherein said first layer has a maximum thickness of about 13/8 to 15/8 inches, said second layer has a maximum thickness of about 7/8 to 11/8 inches and said third layer has a maximum thickness of about 13/8 to 15/8 inches.

Claim 8

A seat cushion as recited in claim 1, wherein said second layer has a pair of recesses formed therein which results in the depressions in the upper surface of said seat cushion, said recess begin of a maximum depth of about 85% to 100% of the maximum thickness of said second layer at the front edge of said second layer and lessening in depth in a front to rear direction.

Claim 9

A seat cushion as recited in claim 1 wherein each of said layers shares a common front, rear, first side and second side edge.

Claim 10

A seat cushion as recited in claim 1 wherein the first layer has a higher 65% PFD value than said second layer and a higher 65% IFD value than said third layer.

Claim 11

A wheelchair cushion as recited in claim 1, wherein said upper surface of said cushion slopes continuously from said front edge of said cushion to said rear edge of said cushion so as to form a wedge shaped seat cushion.

Claim 12

A seat cushion as recited in claim 1, wherein the height of the front and rear edges of said second layer is equal, the height of the front and rear edges of said third layer is equal, and the front edge of said first layer is higher than the rear edge of said first layer so as to form a sloping upper surface in said first layer which defines the downwardly sloping upper surface of said seat cushion.

Claim 13

A seat cushion as recited in claim 11, wherein the front edge of said seat cushion is 33/4 to 41/4 inches in height and the rear edge of said seat cushion is 21/2 to 23/4 inches in height.

Claim 14

A seat cushion as recited in claim 11, wherein said first layer has a compression modulus value between 2.4 and 2.6, said second layer has a compression modulus value between 1.9 and 2.1, and said third layer has a compression modulus value between 2.7 and 3.3.

Claim 15

A seat cushion as recited in claim 13, wherein the density of said first layer is about 2.75 to 2.85 lb/ft 3 , the density of said second layer is from 1.80 to 1.90 lb/ft 3 and the density of said third layer is from 2.30 to 2.40 lb/ft 3 .

Claim 16

A seat cushion as recited in claim 1, wherein said second layer has recesses formed therein which result in the formation of the depressions in the upper surface of said seat cushion.

Claim 17

A seat cushion as recited in claim 15, wherein the upper surface of said third layer is convoluted.

Claim 18

A seat cushion as recited in claim 15, wherein the rearward most edge of said depressions is positioned less than half of the distance between the front edge and the rear edge of said seat cushion.

Claim 19

A seat cushion as recited in claim 1, wherein said third layer is at least 35% longer in a front to rear direction than said first and second layers so as to form a back support section in said seat cushion.

Claim 20

A seat cushion as recited in claim 18, wherein the upper surface of said third layer is convoluted.

Claim 21

A seat cushion as recited in claim 19, wherein the convoluted upper surface includes a plurality of protrusions having integral corners and a plurality of valleys positioned between said protrusions.

Claim 22

A wheel chair cushion, comprising: a base layer formed of a foam material and having a bottom surface and an upper surface which slopes downwardly with respect to said bottom surface in a front to rear direction; an intermediate layer formed of a foam material and secured to the upper surface of said base layer, said intermediate layer having a front edge, a rear edge and two side edges with the rear and two side edges being essentially of the same height, a pair of laterally spaced recesses being formed in said intermediate layer between said two side edges and extending form the front edge toward the rear edge of said second layer; a top layer formed of a foam material and secured to the upper surface of said intermediate layer and extending into the recesses formed in said intermediate layer so as to define a pair of depression formed in an upper surface of said seat cushion; and said base layer being firmer than said top and intermediate layers.

Claim 23

A wheel chair cushion, comprising: a base layer formed of a foam material and having a bottom surface and an upper surface which slopes downwardly with respect to said bottom surface in a front to rear direction; an intermediate layer formed of a foam material and secured to the upper surface of said base layer, said intermediate layer having a front edge, a rear edge and two side edges with the rear and two side edges being essentially of the same height, a pair of laterally spaced recesses being formed in said intermediate layer between said two side edges and extending form the front edge toward the rear edge of said second layer; a top layer formed of a foam material and secured to the upper surface of said intermediate layer and extending into the recesses formed in said intermediate layer so as to define a pair of depression formed in an upper surface of said seat cushion; and said base layer being firmer than said top and intermediate layers.

Claim 24

A wheel chair cushion as recited in claim 21 wherein said seat cushion has an upper surface which slopes downwardly with respect to said bottom surface of said base layer at an angel from about 4.5° to 5.5°.

Claim 25

A wheel chair cushion as recited in claim 21, wherein the upper surface of said top layer is convoluted and said to player is of constant thickness.

Claim 26

A wheel chair cushion as recited in claim 23, wherein a solid block of the material forming said intermediate layer has a 65% IFD value, which is higher than a similar shaped solid block of the material forming said top layer, and a similar solid shaped block of the material forming said base layer has a higher 65% IFD value than said block of the material forming said intermediate layer.

Claim 27

A wheel chair cushion, comprising a base layer having a front edge and a rear edge; an intermediate layer secured to an upper surface of said base layer; a top layer having a bottom surface partially supported by said intermediate layer, said to player including an extended portion extending out away from the intermediate layer, said extended portion being dimensioned and arranged for use as a wheel chair backrest cushion member so as to provided a backrest support when said wheelchair cushion is supported by a wheelchair, and wherein said top layer is at least 35% longer in a front to rear direction than said intermediate layer.

Claim 28

A wheel chair cushion, comprising a base layer having a front edge and a rear edge; an intermediate layer secured to an upper surface of said base layer; a top layer having a bottom surface partially supported by said intermediate layer, said to player including an extended portion extending out away from the intermediate layer, said extended portion being dimensioned and arranged for use as a wheel chair backrest cushion member so as to provided a backrest support when said wheelchair cushion is supported by a wheelchair, and wherein said top layer is at least 35% longer in a front to rear direction than said intermediate layer.

Claim 29

A wheelchair cushion as recited in claim 25 wherein said top layer has a convoluted upper surface.

Claim 30

A wheelchair cushion as recited in claim 25 wherein said base layer is formed of polyurethane foam material with the front edge being higher than the rear edge so as to form a wedge shaped layer.

Claim 31

A wheelchair cushion as recited in claim 25 wherein a solid block of the material forming said top layer has a 65% IFD value which is less than the 65% IFD value of a solid block of the material forming said intermediate layer and said base layer.

Claim 32

A wheelchair cushion as recited in claim 28 wherein said wheelchair cushion has an upper surface which slopes downwardly with respect to a bottom surface of said base layer form a forward edge of said cushion toward the backrest portion.

Claim 33

A seat cushion, comprising: a first layer having a front edge, a rear edge, a bottom surface and an upper surface; a second layer having a front edge, a rear edge, a bottom surface and an upper surface with the bottom surface of said second layer supported by the upper surface of said first layer; a third layer having a front edge, a rear edge, a bottom surface and an upper surface with at least a portion of the bottom surface of said third layer supported by the upper surface of said second layer; said first, second and third layers being formed of a foam material, and said first layer being formed of a foam material which has different IFD values than said second layer and said second layer being formed of a foam material which has different IFD values than said third layer; said first, second and third layers begin dimensioned and arranged such that an upper surface of said seat cushion slopes downwardly in a direction from the front of said seat cushion to the rear of said seat cushion within a range of b 41/2 to 51/2 degrees; and said first, second and third layers being dimensioned and arranged such that the upper surface of said seat cushion defines a pair of depressions that each originate at the front edge of said seat cushion an extend rearwardly toward the rear edge of said cushion, said depressions being laterally spaced from one another between two side edges of said seat cushion and said second layer has a recesses formed therein which result in the formation of the depression in the uppers surface of said seat cushion, and said rearward most edge of said depressions is positioned less than half of the distance between the front edge and the rear edge of said seat cushion.

Claim 34

A seat cushion, comprising: a first layer having a front edge, a rear edge, a bottom surface and an upper surface; a second layer having a front edge, a rear edge, a bottom surface and an upper surface with the bottom surface of said second layer supported by the upper surface of said first layer; a third layer having a front edge, a rear edge, a bottom surface and an upper surface with at least a portion of the bottom surface of said third layer supported by the upper surface of said second layer; said first, second and third layers being formed of a foam material, and said first layer being formed of a foam material which has different IFD values than said second layer and said second layer being formed of a foam material which has different IFD values than said third layer; said first, second and third layers begin dimensioned and arranged such that an upper surface of said seat cushion slopes downwardly in a direction from the front of said seat cushion to the rear of said seat cushion within a range of b 41/2 to 51/2 degrees; and said first, second and third layers being dimensioned and arranged such that the upper surface of said seat cushion defines a pair of depressions that each originate at the front edge of said seat cushion an extend rearwardly toward the rear edge of said cushion, said depressions being laterally spaced from one another between two side edges of said seat cushion and said second layer has a recesses formed therein which result in the formation of the depression in the uppers surface of said seat cushion, and said rearward most edge of said depressions is positioned less than half of the distance between the front edge and the rear edge of said seat cushion.

Claim 35

A seat cushion, comprising: a first layer having a front edge, a rear edge, a bottom surface and an upper surface; a second layer having a front edge, a rear edge, a bottom surface and an upper surface with the bottom surface of said second layer supported by the upper surface of said first layer; a third layer having a front edge, a rear edge, a bottom surface and an upper surface with at least a portion of the bottom surface of said third layer supported by the upper surface of said second layer; said first, second and third layers being formed of a foam material , and said first layer being formed of a foam material which has different IFD values than said second layer and said second layer being formed of a foam material which has different IFD values than said third layer; said first, second and third layers being dimensioned and arranged such that an upper surface of said seat cushion, slopes downwardly with resect to a bottom surface of said seat cushion in a direction from a front edge of said seat cushion, and said upper surface of said seat cushion slopes downwardly from a starting location at said front of said seat cushion edge to an ending location at a rear of said seat cushion edge so as to define a wedge shaped seat cushion; and said first, second and third layers begin dimensioned and arranged such that the upper surface of said seat cushion defines a pair of depressions that each originate at the front edge of said seat cushion and extend rearwardly toward the rear edge of said cushion, and wherein a rearward most edge of each of said depressions is positioned less than half the distance between the front edge and rear edge of said seat cushion, said depressions being laterally spaced from one another to opposite sides of an intermediate portion of the front edge of said seat cushion and between two side edges of said seat cushion.

Claim 36

A seat cushion, comprising: a first layer having a front edge, a rear edge, a bottom surface and an upper surface; a second layer having a front edge, a rear edge, a bottom surface and an upper surface with the bottom surface of said second layer supported by the upper surface of said first layer; a third layer having a front edge, a rear edge, a bottom surface and an upper surface with at least a portion of the bottom surface of said third layer supported by the upper surface of said second layer; said first, second and third layers being formed of a foam material , and said first layer being formed of a foam material which has different IFD values than said second layer and said second layer being formed of a foam material which has different IFD values than said third layer; said first, second and third layers being dimensioned and arranged such that an upper surface of said seat cushion, slopes downwardly with resect to a bottom surface of said seat cushion in a direction from a front edge of said seat cushion, and said upper surface of said seat cushion slopes downwardly from a starting location at said front of said seat cushion edge to an ending location at a rear of said seat cushion edge so as to define a wedge shaped seat cushion; and said first, second and third layers begin dimensioned and arranged such that the upper surface of said seat cushion defines a pair of depressions that each originate at the front edge of said seat cushion and extend rearwardly toward the rear edge of said cushion, and wherein a rearward most edge of each of said depressions is positioned less than half the distance between the front edge and rear edge of said seat cushion, said depressions being laterally spaced from one another to opposite sides of an intermediate portion of the front edge of said seat cushion and between two side edges of said seat cushion.