Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
99 words
I. A ribbon cassette comprising a casing (6), a primary spool (8) in the casing upon which unused ribbon is wound, and a secondary spool (10) in the casing upon which used ribbon is wound, the secondary spool being provided with means (12) to be engaged by a drive member to cause ribbon to be drawn from the primary spool (8) on to the secondary spool (10), wherein the cassette comprises means (20, 21) to resist reverse winding of the primary spool, said means in part at least being located within the spool on which the ribbon is wound.
Claim 2
Dependent Claim
77 words
A ribbon cassette according to Claim wherein said means comprises a first toothed element (20) forming part of or fixedly mounted on the spool (10), and a second toothed element (21) rotationally fixed in relation to the spool, the two elements being urged into engagement with one another, with the teeth so arranged so as to permit rotation of the spool in one direction but to subject rotation in the opposite direction to a significantly higher restraint.
Claim 3
Dependent Claim
21 words
A ribbon cassette according to Claim 2 wherein spring means (28, 30) is provided to urge the toothed elements into engagement.
Claim 4
Dependent Claim
20 words
A ribbon cassette according to Claim 3 wherein the spring means (28, 30) is mounted on the spool (20, 26).
Claim 5
Dependent Claim
89 words
A ribbon cassette comprising a casing (6), a primary spool (8) in the casing upon which unused ribbon is wound, and a secondary spool (10) in the casing upon which used ribbon is wound, the secondary spool being provided with means (12) to be engaged by a drive member to cause ribbon to be drawn from the primary spool onto the secondary spool, the cassette comprising a spring element (28, 30, 32) to maintain tension on the ribbon, said spring element being mounted on the primary spool (20, 26).
Claim 6
Dependent Claim
28 words
A ribbon cassette according to Claim 5 wherein said spring element (28, 30, 32) affords in part at least means to resist reverse rotation of the primary spool.
Claim 7
Dependent Claim
23 words
A ribbon cassette according to Claim 6 wherein said spring element (28, 30, 32) is afforded by the spring means of Claim 3.
Claim 8
Dependent Claim
107 words
A ribbon cassette comprising a casing (6), a primary spool (8) in the casing upon which unused ribbon is wound, a secondary spool (10) in the casing upon which used ribbon is wound, the secondary spool (10) being provided with means (12) to be engaged by a drive member to cause ribbon to be drawn from the primary spool onto the secondary spool, wherein the casing is provided with a mounting element (16) upon which the primary spool is mounted for rotation, and an insert member (80) which may be inserted into the casing (6) to engage the primary spool (8) to restrain rotation of the spool.
Claim 9
Dependent Claim
61 words
A ribbon cassette according to Claim 8 wherein the casing is provided with a slot (78) so positioned as to enable the insert member (80) to be engaged within a boss (16) of the casing upon which the spool (8) is mounted, and so as to project a small extent beyond the circumference of the boss, to engage the spool (8).
Claim 10
Dependent Claim
65 words
A ribbon cassette according to Claim 9 wherein the insert member (80) is resiliently deformable, and is of such a size that such insertion involves deformation thereof, frictional engagement between the insert member (80) and the casing (6) under the action of the resilience of the insert member (80) frictionally restraining rotation of the spool and frictionally retaining the insert member in its inserted position.
Claim 11
Dependent Claim
58 words
1 I. A ribbon cassette according to Claim 8 wherein the insert member (80) comprises an operative portion (82) to perform the restraint to rotation of the spool, and a supplementary portion (84) adapted for manual grasping, which supplementary portion (84) remains exterior of the casing to enable the operative portion to be withdrawn from its inserted position.
Claim 12
Dependent Claim
28 words
A ribbon cassette according to Claim I wherein the operative portion (82) lies in a plane generally at right angles to the plane of the supplementary portion (84).