Homogeneous integrally molded skate and method for molding
AssigneeRoller Derby Skate Corporation
InventorEdwin Seltzer
Life of this patent
Estimating the term…
Abstract
A unitary, homogeneously molded boot and support for a roller or ice skate is provided as a one piece unit having no juncture between the boot and the support. The boot may be molded with either a roller skate or an ice skate chassis by forming the chassis of a first plastic having a high stiffness characteristic when cooled. The chassis is then placed in a boot injection mold and a second heated plastic is injected into contact with the chassis. The second plastic is more flexible when cooled than the first plastic, but is compatible therewith so that the two flow together and form an integral, unitary structure. The unitary boot is formed with a pivotal upper due to three slits in the boot which cooperate to provide opposite fulcrum sections about which the upper pivots.
Claims27
A plastic skate molded as a single, homogenous, integrally molded piece from compatible plastics having different flexibility characteristics comprising:
- a boot portion for receiving a skater's foot having a molded plastic outer shell including a toe portion, a heel portion spaced from said toe portion, first and second opposed sidewall portions extending longitudinally from said toe to said heel portion, and a base portion extending between said sidewall portions and said heel and toe portions, said base portion including a bottom side and a top side surface which forms the bottom foot support for said skater's foot and which with said heel, toe and sidewall portions defines a cavity within said molded outer shell for receiving a skater's foot which is supported and enclosed thereby, said outer shell being formed of a first thermoplastic elastomer and
- a support structure molded integrally with said base portion and extending from the bottom side of said base portion, said support structure being formed of a second thermoplastic elastomer which is different from said first elastomer, said second elastomer, when cooled, being more rigid and less flexible than said first elastomer when cooled, said boot portion and support structure being formed as a single unitary piece with no junctures therebetween and no separable moving parts.
A plastic skate molded as a single, homogenous, integrally molded piece comprising:
- a boot portion for receiving a skater's foot having a molded outer shell including a toe portion, a heel portion spaced from said toe portion, first and second opposed sidewall portions extending longitudinally from said toe to said heel portion, and a base portion extending between said sidewall portions and said heel and toe portions, said base portion including a bottom side and a top side surface which forms the bottom foot support for said skater's foot and which with said heel, toe and sidewall portions defines a cavity within said molded outer shell for receiving a skater's foot which is supported and enclosed thereby, said outer shell including a heel slit formed in the heel portion thereof and spaced above said base portion, said heel slit having a first end positioned in said first sidewall portion and extending through said outer shell from said first sidewall portion across said heel portion to a second end positioned in said second sidewall portion, and
- a boot upper extending above said heel slit, said boot upper including first and second opposed flaps extending above said first and second opposed sidewall portions, each said flap including a bottom edge defined by an inclined slit extending through said outer shell, each said inclined slit angling downwardly and rearwardly of said outer shell from an open end toward the first or second end of said heel slit, and
- a support structure molded integrally with said base portion and extending from the bottom side of said base portion, said boot portion and support structure being formed as a unitary piece with no junctures therebetween.
A molded plastic boot for receiving the foot of a wearer comprising:
- a molded outer shell including a toe portion, a heel portion spaced from the toe portion, first and second opposed sidewall portions extending longitudinally from said toe to heel portion, and a sole portion extending between said sidewall portions and said heel and toe portions to define a cavity within said molded outer shell for receiving a wearer's foot which is supported and enclosed thereby,
- said molded outer shell including a heel slit formed in the heel portion thereof and spaced above said base portion, said heel slit having a first end positioned in said first sidewall portion and extending through said boot from said first sidewall portion across said heel portion to a second end positioned in said second sidewall portion, and
- a boot upper extending above said first slit, said boot upper including first and second opposed flaps extending above said first and second opposed sidewall portions, each said flap including a bottom edge defined by an inclined slit extending through said boot, each said inclined slit angling downwardly and rearwardly of said boot from an open end toward the first or second end of said heel slit.
A method for injection molding an integrally molded skate boot and support chassis for a skate blade or wheels comprising the steps of:
- molding the support chassis of a first thermoplastic plastic to include plastic attachment pedestals for connection to a boot,
- placing the molded support chassis in a boot forming injection mold with only the support pedestals exposed to plastic injected within the boot forming injection mold, and
- injecting a second heated thermoplastic plastic which differs from said first thermoplastic plastic into the boot forming injection mold into contact with said pedestals to form a plastic boot shell,
- said first and second thermoplastic plastics being compatible thermoplastics so that the plastic of said pedestals flows into the second thermoplastic plastic of said boot shell at the temperature at which said second thermoplastic plastic is injected into the boot forming mold.
Dependencies are inferred from the claim text.