Method for fabrication of plastic footwear

Claim 1

A method of manufacturing slippers of heat-sealable synthetic polymeric sheeting material, comprising: advancing a first elongated strip of said material in a longitudinal direction through a foot-opening forming operation; forming foot-openings at equally spaced distances along said strip; subsequently bringing said first strip and a second strip of said material into face to face contact with one another; advancing said first and second strips together through a cutting and sealing operation by pushing said strips toward said operation from one side thereof and pulling or withdrawing said strips from the other side of said operation, said pushing and pulling being performed with equal force, over equal distances and at the same time; during said cutting and sealing operation, exerting firm pressure on the exposed faces of both of said strips in at least one narrow region surrounding one of said foot-openings, said region being spaced outwardly from said one foot-opening and having an outline generally conformable to the human foot; raising the temperature of said strips within said region to the temperature at which saId strips will coalesce with one another within said region; maintaining said temperature until said strips are permanently bonded in said region; and separating a completed slipper from the material lying outside of said region.

Claim 2

A method of manufacturing slippers of heat-sealable synthetic polymeric sheeting material, comprising: advancing a first elongated strip of said material in a longitudinal direction through a foot-opening forming operation; forming foot-openings at equally spaced distances along said strip; subsequently bringing said first strip and a second strip of said material into face to face contact with one another; advancing said first and second strips together through a cutting and sealing operation by pushing said strips toward said operation from one side thereof and pulling or withdrawing said strips from the other side of said operation, said pushing and pulling being performed with equal force, over equal distances and at the same time; during said cutting and sealing operation, exerting firm pressure on the exposed faces of both of said strips in at least one narrow region surrounding one of said foot-openings, said region being spaced outwardly from said one foot-opening and having an outline generally conformable to the human foot; raising the temperature of said strips within said region to the temperature at which saId strips will coalesce with one another within said region; maintaining said temperature until said strips are permanently bonded in said region; and separating a completed slipper from the material lying outside of said region.

Claim 6

A method of manufacturing slippers of heat-sealable synthetic polymeric sheeting material, comprising: advancing a first elongated strip of said material in a longitudinal direction through a foot-opening forming operation; forming elongated foot-openings at equally spaced distance along said strip; subsequently bringing said first strip and a second strip of said material into face to face contact with one another; exerting firm pressure on the exposed faces of said strips in at least one narrow region surrounding one of said foot-openings, said region being spaced outwardly from said foot-opening and having an elongated outline generally conformable to the human foot, said outline being elongated in generally the same direction as said foot-opening; raising the temperature of said strips within said region to the temperature at which said strips will coalesce with one another within said region; maintaining said temperature until said strips are bonded within said region; and separating a completed slipper from the material lying outside of said region.

Claim 7

A method of manufacturing slippers of heat-sealable synthetic polymeric sheeting material, comprising: advancing a first elongated strip of said material in a longitudinal direction through a foot-opening forming operation; forming elongated foot-openings at equally spaced distance along said strip; subsequently bringing said first strip and a second strip of said material into face to face contact with one another; exerting firm pressure on the exposed faces of said strips in at least one narrow region surrounding one of said foot-openings, said region being spaced outwardly from said foot-opening and having an elongated outline generally conformable to the human foot, said outline being elongated in generally the same direction as said foot-opening; raising the temperature of said strips within said region to the temperature at which said strips will coalesce with one another within said region; maintaining said temperature until said strips are bonded within said region; and separating a completed slipper from the material lying outside of said region.

Claim 11

A method according to claim (9) 11 wherein both of said sheets are of stretchy cellular material.

Claim 12

A method of manufacturing slippers of a heat-sealable synthetic polymeric sheeting material comprising: providing first and second sheets of the synthetic polymeric sheeting material, at least one of which is stretchy cellular material; forming an elongated foot opening in the first sheet of said material; subsequently bringing the first sheet together with the second sheet of said material in face to face relationship; exerting firm pressure on the exposed faces of the sheets in at least one narrow region surrounding the foot opening, said region being spaced outwardly from the foot opening and having an elongated outline generally conformable to the human foot, said outline being elongated in generally the same direction as said foot opening; raising the temperature of the sheets within said region to unite said sheets with one another within said region; searing the periphery of the foot opening by collapsing a narrow portion of the material surrounding the opening and heating it while under compression; and separating a slipper from the material lying outside of said region.

Claim 13

A method of manufacturing slippers of a heat-sealable synthetic polymeric sheeting material comprising: providing first and second sheets of the synthetic polymeric sheeting material, at least one of which is stretchy cellular material; forming an elongated foot opening in the first sheet of said material; subsequently bringing the first sheet together with the second sheet of said material in face to face relationship; exerting firm pressure on the exposed faces of the sheets in at least one narrow region surrounding the foot opening, said region being spaced outwardly from the foot opening and having an elongated outline generally conformable to the human foot, said outline being elongated in generally the same direction as said foot opening; raising the temperature of the sheets within said region to unite said sheets with one another within said region; searing the periphery of the foot opening by collapsing a narrow portion of the material surrounding the opening and heating it while under compression; and separating a slipper from the material lying outside of said region.

Claim 33

A method of manufacturing slippers of heat sealable polyurethane foam material comprising: punching an elongated foot-opening in a first sheet of polyurethane foam; subsequently bringing said first sheet together with a second sheet of polyurethane foam in face to face relationship; exerting firm pressure on the exposed faces of said sheets in at least one narrow region surrounding said foot-opening, said region being spaced outwardly from said foot-opening and having an elongated outline generally conformable to the human foot, said outline being elongated in generally the same direction as said foot-opening; raising the temperature of said sheets within said region to unite said sheets with one another within said region; wherein, the application of heat is accomplished with the aid of a heated die having a face corresponding to the shape of said region; searing the periphery of the foot-opening by collapsing a narrow portion of the material surrounding the opening and heating it while under compression; and separating a slipper from the material lying outside of said region while said sheets are still under pressure.

Claim 34

A method of manufacturing slippers of heat sealable polyurethane foam material comprising: punching an elongated foot-opening in a first sheet of polyurethane foam; subsequently bringing said first sheet together with a second sheet of polyurethane foam in face to face relationship; exerting firm pressure on the exposed faces of said sheets in at least one narrow region surrounding said foot-opening, said region being spaced outwardly from said foot-opening and having an elongated outline generally conformable to the human foot, said outline being elongated in generally the same direction as said foot-opening; raising the temperature of said sheets within said region to unite said sheets with one another within said region; wherein, the application of heat is accomplished with the aid of a heated die having a face corresponding to the shape of said region; searing the periphery of the foot-opening by collapsing a narrow portion of the material surrounding the opening and heating it while under compression; and separating a slipper from the material lying outside of said region while said sheets are still under pressure.

Claim 35

A method of manufActuring slippers of heat-sealable polyurethane foam material, comprising: advancing a first elongated strip of polyurethane foam in a longitudinal direction through a foot-opening forming operation; punching elongated foot-openings at equally spaced distances along said strip; subsequently bringing said first strip and a second strip of polyurethane foam into face to face contact with one another; exerting firm pressure on the exposed faces of said strips in at least one narrow region surrounding one of said foot-openings, said region being spaced outwardly from said foot-opening and having an elongated outline generally conformable to the human foot, said outline being elongated in generally the same direction as said foot-opening; raising the temperature of said strips within said region to the temperature at which said strips will coalesce with one another within said region; and wherein the application of heat is accomplished with the aid of a heated die having a face corresponding to the shape of said region; maintaining said temperature until said strips are bonded within said region; searing the periphery of the foot-opening by collapsing a narrow portion of the material surrounding the opening and heating it while under compression; and separating a completed slipper from the material lying outside of said region while said strips are still under pressure.

Claim 36

A method of manufActuring slippers of heat-sealable polyurethane foam material, comprising: advancing a first elongated strip of polyurethane foam in a longitudinal direction through a foot-opening forming operation; punching elongated foot-openings at equally spaced distances along said strip; subsequently bringing said first strip and a second strip of polyurethane foam into face to face contact with one another; exerting firm pressure on the exposed faces of said strips in at least one narrow region surrounding one of said foot-openings, said region being spaced outwardly from said foot-opening and having an elongated outline generally conformable to the human foot, said outline being elongated in generally the same direction as said foot-opening; raising the temperature of said strips within said region to the temperature at which said strips will coalesce with one another within said region; and wherein the application of heat is accomplished with the aid of a heated die having a face corresponding to the shape of said region; maintaining said temperature until said strips are bonded within said region; searing the periphery of the foot-opening by collapsing a narrow portion of the material surrounding the opening and heating it while under compression; and separating a completed slipper from the material lying outside of said region while said strips are still under pressure.

Claim 37

A method of manufacturing slippers of heat-sealable stretchy cellular material comprising: advancing a first elongated strip of said material in a longitudinal direction through a foot-opening forming operation; punching foot-openings at equally spaced distances along said strip; subsequently bringing said first strip and a second strip of said material into face to face contact with one another; advancing said first and second strips together through a cutting and sealing operation by pushing said strips toward said operation from one side thereof and pulling or withdrawing said strips from the other side of said operation, said pushing and pulling being performed with equal force, over equal distances and at the same time; during said cutting and sealing operation, exerting firm pressure on the exposed faces of both of said strips in at least one narrow region surrounding one of said foot-openings, said region being spaced outwardly from said one foot-opening and having an outline generally conformable to the human foot; raising the temperature of said strips within said region to the temperature at which said strips will coalesce with one another within said region; wherein the application of heat is accomplished with the aid of a heated die having a face corresponding to the shape of said region; maintaining said temperature until said strips are permanently bonded in said region; and separating a completed slipper from the material lying outside of said region while said sheets are still under pressure.

Claim 38

A method of manufacturing slippers of heat-sealable stretchy cellular material comprising: advancing a first elongated strip of said material in a longitudinal direction through a foot-opening forming operation; punching foot-openings at equally spaced distances along said strip; subsequently bringing said first strip and a second strip of said material into face to face contact with one another; advancing said first and second strips together through a cutting and sealing operation by pushing said strips toward said operation from one side thereof and pulling or withdrawing said strips from the other side of said operation, said pushing and pulling being performed with equal force, over equal distances and at the same time; during said cutting and sealing operation, exerting firm pressure on the exposed faces of both of said strips in at least one narrow region surrounding one of said foot-openings, said region being spaced outwardly from said one foot-opening and having an outline generally conformable to the human foot; raising the temperature of said strips within said region to the temperature at which said strips will coalesce with one another within said region; wherein the application of heat is accomplished with the aid of a heated die having a face corresponding to the shape of said region; maintaining said temperature until said strips are permanently bonded in said region; and separating a completed slipper from the material lying outside of said region while said sheets are still under pressure.

Claim 40

A method of manufacturing slippers of heat-sealable stretchy cellular material comprising: incrementally advancing a first elongated strip of said material in a longitudinal direction through a foot-opening forming station; punching foot openings at equally spaced distances along said strip while it is at rest at said foot-opening forming station; advancing said first elongated strip from said foot-opening forming station along a path of advancement extending to a cutting and sealing station, said punching station and said cutting and sealing station being separated by a distance along said path approximately equal to a whole number multiple of the length of each incremental movement of the material as it advances over said path; bringing said first strip and a second strip of said material together along said path between said pUnching station and said cutting and sealing station; incrementally advancing said first and second strips together through said cutting and sealing station; performing the advancing of said first strip through said punching station and the advancing of said first and second strips together through said cutting and sealing station by pushing said strips towards said stations from one side thereof and pulling or withdrawing said strips from the other side of said stations, said pushing and pulling being performed with equal force, over equal distances and at the same time; at said cutting and sealing station, exerting firm pressure on the exposed faces of both of said strips while they are at rest in at least one narrow region surrounding one of said foot openings, said exerting of pressure being synchronized with the punching of said foot openings in said first elongated strip, said region being spaced outwardly from said one foot opening and having an outline generally conformable to the human foot; raising the temperature of said strips within said region to the temperature at which said strips will coalesce with one another within said region; maintaining said temperature until said strips are permanently bonded in said region; and separating a completed slipper from the material lying outside of said region.

Claim 41

A method of manufacturing slippers of heat-sealable stretchy cellular material comprising: incrementally advancing a first elongated strip of said material in a longitudinal direction through a foot-opening forming station; punching foot openings at equally spaced distances along said strip while it is at rest at said foot-opening forming station; advancing said first elongated strip from said foot-opening forming station along a path of advancement extending to a cutting and sealing station, said punching station and said cutting and sealing station being separated by a distance along said path approximately equal to a whole number multiple of the length of each incremental movement of the material as it advances over said path; bringing said first strip and a second strip of said material together along said path between said pUnching station and said cutting and sealing station; incrementally advancing said first and second strips together through said cutting and sealing station; performing the advancing of said first strip through said punching station and the advancing of said first and second strips together through said cutting and sealing station by pushing said strips towards said stations from one side thereof and pulling or withdrawing said strips from the other side of said stations, said pushing and pulling being performed with equal force, over equal distances and at the same time; at said cutting and sealing station, exerting firm pressure on the exposed faces of both of said strips while they are at rest in at least one narrow region surrounding one of said foot openings, said exerting of pressure being synchronized with the punching of said foot openings in said first elongated strip, said region being spaced outwardly from said one foot opening and having an outline generally conformable to the human foot; raising the temperature of said strips within said region to the temperature at which said strips will coalesce with one another within said region; maintaining said temperature until said strips are permanently bonded in said region; and separating a completed slipper from the material lying outside of said region.