Cassette for a printing ribbon for typewriters
First Claim
1. A cassette for a printing ribbon for typewriters, comprising:
- a casing, having a slot and an opening;
a supply spool accommodated in said casing and having a tube on to which a printing ribbon is wound;
an anti-unrolling element to prevent unrolling movements of said ribbon when said cassette is not fitted to a typewriter and having a first portion which can be inserted into said slot in said casing and a second portion;
said anti-unrolling element comprising a hinge element connecting said second portion to said first portion;
said second portion being movable on the outside of said casing by means of said hinge element from an inoperative position to an operative position; and
said second portion comprising a hook element which can be inserted through said opening in said casing to engage said tube and positively block said supply spool when said second portion is in said operative position.
1 Assignment
0 Petitions
Accused Products
Abstract
A cassette for a printing ribbon comprises a casing accommodating a supply spool which has a tube on which the printing ribbon is wound. An anti-unrolling element of plastics material comprises two portions of elongate shape, which are connected by means of an integral elastic hinge. The first portion performs a guiding and positioning function and is accommodated by means of a slot within the casing. The second portion has a blocking function with regard to the tube, and is movable on the outside of the casing, by means of the elastic hinge, from an inoperative position in which it is aligned with the first portion to an operative position in which it is rotated through 180° and is substantially in superposed relationship with the first portion. The second portion is provided with a hook element which, in its operative position, engages the tube through an opening in the casing for positively blocking the supply spool both during storage and during transportation of the cassette to inhibit unrolling in a simple and reliable manner.
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Citations
20 Claims
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1. A cassette for a printing ribbon for typewriters, comprising:
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a casing, having a slot and an opening; a supply spool accommodated in said casing and having a tube on to which a printing ribbon is wound; an anti-unrolling element to prevent unrolling movements of said ribbon when said cassette is not fitted to a typewriter and having a first portion which can be inserted into said slot in said casing and a second portion; said anti-unrolling element comprising a hinge element connecting said second portion to said first portion; said second portion being movable on the outside of said casing by means of said hinge element from an inoperative position to an operative position; and said second portion comprising a hook element which can be inserted through said opening in said casing to engage said tube and positively block said supply spool when said second portion is in said operative position. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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17. A cassette for a printing ribbon for typewriters, comprising:
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a casing, having a slot and an opening; a supply spool accommodated in said casing and having a tube on to which a printing ribbon is wound; anti-unrolling means to prevent unrolling of said ribbon when said cassette is not fitted to a typewriter and having a first portion inserted into said slot in said casing and a second portion; said first portion having a central groove open at an inner end of said first portion and defining a fork, said fork engaging opposed sides of said tube to guide and position said first portion; said second portion being movable on the outside of said casing from an inoperative position to an operative position and comprising blocking means inserted through said opening in said casing to engage said tube and positively block said supply spool against rotation when said second portion is in said operative position. - View Dependent Claims (18)
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19. A cassette for a printing ribbon for typewriters, comprising:
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a casing, having a plurality of openings; a supply spool accommodated in said casing and having a central member on to which a printing ribbon is wound; a one-piece anti-unrolling element to prevent unrolling of said ribbon when said cassette is not fitted to a typewriter and having a first portion which can be inserted into a first one of said openings in said casing and a second portion, said anti-unrolling element further comprising an integral hinge connecting said second and first portions; said second portion being movable on the outside of said casing by means of said hinge from an inoperative position to an operative position, and comprising blocking means which can be inserted through a second one of said openings in said casing to engage said supply spool and positively block said supply spool against rotation when said second portion is in said operative position. - View Dependent Claims (20)
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Specification