Three dimensional surface shaping of synthetic foam pads by continuous rotary process

A method for shaping a resilient material to substantially mirror a desired three dimensional surface geometry including raised portions and depressions, comprising the steps of:

• providing a die with a die surface having said desired three dimensional geometry;
• providing a slab of resilient material;
• pressing said slab against said die surface to compress some portions of said slab to a reduced thickness against said raised portions and extrude other portions of said slab into said depressions;
• cutting away said other portions from said slab;
• and
• allowing said some portions to expand in thickness to an uncompressed state.

A method for making a support pad of synthetic foam having a three-dimensionally shaped support surface characterized by raised portions separated by depressions, comprising the steps of:

• providing resilient synthetic foam material having a planar surface;
• providing a die having a cylindrical die surface with raised die portions separated by die depressions, and a pressure roller parallel to said die surface;
• turning at least one of said die and said pressure roller;
• feeding said foam material between said die and said pressure roller with said planar surface facing said die roller so as to compress Some portions of said foam material against said raised die portions to a reduced thickness and extrude other portions of said foam material into said die depressions;
• cutting away said other portions;
• and
• allowing said some portions to rise resiliently to an uncompressed thickness thereby to define depressions in said foam material corresponding to said other portions.

A method for shaping resilient material comprising the steps of:

• providing a slab of resilient material;
• providing a die having raised portions separated by depressions;
• pressing said slab against said die to compress some portions of said slab to a reduced thickness against said raised portions and extrude other portions of said slab into said depressions while substantially preserving the resilience of said some portions of said slab;
• and
• cutting away said other portions from said slab.

A method for shaping resilient material comprising the steps of:

• providing a slab of resilient material;
• providing a die having raised portions separated by depressions;
• pressing said slab against said die to compress some portions of said slab to a reduced thickness against said raised portions and extrude other portions of said slab into said depressions;
• and
• cutting away said other portions from said slab;
• characterized in that there is substantially no permanent deformation of the slab by said die.

A method for reproducing a desired three dimensional surface geometry on a slab of resilient synthetic foam material of arbitrary length, comprising the steps of:

• providing a die roller with a cylindrical die surface having said desired three dimensional geometry, the geometry having raised portions, depressions and side surfaces between said raised portions and depressions, and a pressure roller, said die roller and pressure roller being mounted for rotation in mutually parallel relationship and spaced apart to define a gap therebetween;
• introducing between said rollers a slab of resilient material of thickness greater than said gap;
• turning said rollers for advancing said slab through said gap such that a surface of said slab is pressed against said die surface to compress some portions of said slab to a reduced thickness against said raised portions and extrude other portions of said slab into said depressions, said other portions constituting less than the entire thickness of said slab;
• cutting away substantially only said other portions from said slab while extruded in said depressions;
• and
• allowing said some portions to expand in thickness to an uncompressed state corresponding in shape to said raised portions separated by depressions in said slab corresponding to said depressions in said die surface;
• such that said slab emerges from said gap with substantially only such foam material removed therefrom as necessary to define said raised portions by forming said depressions and said three dimensional geometry is reproduced with a substantially high degree of accuracy on said surface of said slab, including said raised portions, said depressions and said side surfaces between said raised portions and depressions.

A method for making a support pad of resilient synthetic foam material of arbitrary length having a pad surface extending said length and characterized by raised portions, depressions and side surfaces between said raised portions and depressions, comprising the steps of:

• providing a slab of resilient synthetic foam material of arbitrary length having a top surface extending said length:
• providing a die roller with said raised portions, depressions and side surfaces between said raised portions and depressions defined on a cylindrical die surface on said die roller in a pattern repeating continuously about the circumference of said die roller, and a pressure roller, said die roller and pressure roller being mounted for rotation in mutually parallel relationship and spaced apart to define a gap therebetween;
• introducing between said rollers a slab of resilient synthetic foam material of arbitrary length having a top surface extending said length and of thickness greater than said gap, said arbitrary length being substantially greater than the circumference of said die roller;
• turning said rollers for advancing said slab through said gap such that said top surface of said slab is pressed against said die surface continuously through more than one revolution of said die roller to compress some portions of said slab to a reduced thickness against said raised portions and extrude other portions of said slab into said depressions, said other portions constituting less than the entire thickness of said slab;
• cutting away substantially only said other portions from said slab while extruded into said depressions;
• and
• allowing said some portions to expand in thickness to an uncompressed state;
• such that said raised portions, said depressions and said side surfaces between said raised portions and depressions are all reproduced with a substantially high degree of accuracy on said top surface of said slab in continuous form along said entire arbitrary length.

A method for reproducing a desired three dimensional surface geometry on a slab of resilient synthetic foam material, comprising the steps of:

• providing a continuous die surface having said desired three dimensional geometry, the geometry having raised top surfaces, depressions with bottom surfaces and side surfaces generally transverse to both said top surfaces and said bottom surfaces;
• pressure means spaced from said die surface to define a gap therebetween;
• introducing between said die surface and said pressure means a slab of resilient material of thickness greater than said gap;
• driving at least said die surface for advancing said slab through said gap such that a surface of said slab is pressed against said die surface to compress some portions of said slab to a reduced thickness against said top surfaces and extrude other portions of said slab into contact with said side and bottom surfaces in said depressions, said other portions constituting less than the entire thickness of said slab;
• cutting away substantially only said other portions from said slab while extruded in said depressions;
• and
• allowing said some portions to expand in thickness to an uncompressed state;
• such that said slab emerges from said gap with said three dimensional geometry reproduced with a substantially high degree of accuracy on said surface of said slab, including said raised portions, said depressions and said side surfaces between said raised portions and depressions;
• said other portions being interconnected after said cutting away to form a continuous length of scrap material.