Extrusion head for the manufacture of handrails

Claim 2

An extrusion head for the manufacture of a handrail comprising a die block having a die with an opening of C shaped form from which the handrail is originated, the opening comprising a curved section at each end thereof and a substantially straight section between the ends thereof, means operatively associated with said die for guiding a plurality of threads or cords to the die, a shaped cavity within said die block for the passage of plastic or elastomeric material from an inlet opening for the latter to the die where the body of the handrail is formed, a hollow space within said die block for feeding a band of fabric, intended to cover the concave surface of the handrail, into the shaped cavity, and two grooves in said shaped cavity to compel the plastic or elastomeric material to apply tension to the edges of said band of fabric in a direction perpendicular to the edges and parallel to the straight section of the opening before the band of fabric reaches the die whereby said band does not originate folds and adheres to the plastic or elastomeric material forming the body of the handrail.

Claim 3

An extrusion head for the manufacture of a generally C-shaped handrail, said extrusion head comprising: an outer casing having a generally cylindrical cavity and a duct defined therein, said duct opening into said cavity and having a longitudinal axis which is perpendicular to the longitudinal axis of the cavity; a shaped mandrel in said cavity, said mandrel having an inlet end and an outlet end, said mandrel having a generally curved surface which defines a hollow space with the inner surface of the cavity, said mandrel having defined therein: a plurality of holes, whose longitudinal axes are coplanar and parallel to the longitudinal axis of the cavity, for passage of cords or threads therethrough, and an opening, I-shaped in transverse cross-section; a bar, I-shaped in transverse cross-section, in said I-shaped opening, said bar having a core of a width equal to the distance between facing ends of the C-shaped handrail to be produced and a height equal to the thickness of the facing ends of the handrail to be produced and being of smaller transverse cross-sectional area than said I-shaped opening and defining therebetween a C-shaped space for passage of a band of fabric to cover the concave surface of the handrail, said C-shaped space comprising a curved section at each end thereof and a substantially straight section between the ends thereof; said generally curved surface is symmetrical with respect to the plane of symmetry of said bar and is defined in part by a pair of grooves in the mandrel, each one adjacent the core of the bar, said grooves increasing progressively in depth toward the core of the bar in a direction from said inlet end toward said outlet end so that plastic or elastomeric material fed to said hollow space and said grooves in the mandrel through said duct applies tension to the edges of the band of fabric in a direction perpendicular to the plane of symmetry of the bar and parallel to the straight section of the C-shaped space so that folds are not created in the band and it adheres to the plastic or elastomeric material.

Claim 4

An extrusion head for the manufacture of a generally C-shaped handrail, said extrusion head comprising: an outer casing having a generally cylindrical cavity and a duct defined therein, said duct opening into said cavity and having a longitudinal axis which is perpendicular to the longitudinal axis of the cavity; a shaped mandrel in said cavity, said mandrel having an inlet end and an outlet end, said mandrel having a generally curved surface which defines a hollow space with the inner surface of the cavity, said mandrel having defined therein: a plurality of holes, whose longitudinal axes are coplanar and parallel to the longitudinal axis of the cavity, for passage of cords or threads therethrough, and an opening, I-shaped in transverse cross-section; a bar, I-shaped in transverse cross-section, in said I-shaped opening, said bar having a core of a width equal to the distance between facing ends of the C-shaped handrail to be produced and a height equal to the thickness of the facing ends of the handrail to be produced and being of smaller transverse cross-sectional area than said I-shaped opening and defining therebetween a C-shaped space for passage of a band of fabric to cover the concave surface of the handrail, said C-shaped space comprising a curved section at each end thereof and a substantially straight section between the ends thereof; said generally curved surface is symmetrical with respect to the plane of symmetry of said bar and is defined in part by a pair of grooves in the mandrel, each one adjacent the core of the bar, said grooves increasing progressively in depth toward the core of the bar in a direction from said inlet end toward said outlet end so that plastic or elastomeric material fed to said hollow space and said grooves in the mandrel through said duct applies tension to the edges of the band of fabric in a direction perpendicular to the plane of symmetry of the bar and parallel to the straight section of the C-shaped space so that folds are not created in the band and it adheres to the plastic or elastomeric material.