Method of making light-trapping members for photographic film cassette
First Claim
1. A method of making a pair of light-trapping members from a ribbon having a base fabric and piles, said light-trapping members being used for a photographic film cassette having a cassette shell for rotatably containing a spool with a photographic film wound thereon, a leading end of said photographic film being advanced out of said cassette shell through a film passage mouth formed in said cassette shell by rotation of said spool, said light-trapping members being attached to respective upper and lower inside surfaces of said film passage mouth so as to prevent light from entering in the inside of said cassette shell, said method comprising the steps of:
- twisting said ribbon relative to a ribbon feeding direction;
contacting said piles of said ribbon with a first thermal drum, which extends transverse to said film feeding direction, so as to incline said piles in a width direction of said ribbon at a predetermined inclination angle; and
cutting said ribbon at a predetermined length to obtain said light-trapping members.
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Accused Products
Abstract
Light-trapping members are cut out of a ribbon consisting of a base fabric and piles. The piles of the ribbon are pressed against the peripheral surface of a thermal drum to be inclined in the width direction after the ribbon is passed through and twisted by a twister disposed close to the thermal drum. The light-trapping members with inclined piles are attached to a film passage mouth of a self-advancing-type photographic film cassette with the inclination of the piles directed to the outside of the film passage mouth, so that the leading end of a photographic film can be advanced smoothly by rotation of a spool through the light-trapping members to the outside of the cassette.
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Citations
16 Claims
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1. A method of making a pair of light-trapping members from a ribbon having a base fabric and piles, said light-trapping members being used for a photographic film cassette having a cassette shell for rotatably containing a spool with a photographic film wound thereon, a leading end of said photographic film being advanced out of said cassette shell through a film passage mouth formed in said cassette shell by rotation of said spool, said light-trapping members being attached to respective upper and lower inside surfaces of said film passage mouth so as to prevent light from entering in the inside of said cassette shell, said method comprising the steps of:
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twisting said ribbon relative to a ribbon feeding direction; contacting said piles of said ribbon with a first thermal drum, which extends transverse to said film feeding direction, so as to incline said piles in a width direction of said ribbon at a predetermined inclination angle; and cutting said ribbon at a predetermined length to obtain said light-trapping members. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification