US3677486A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Uniform ribbon feed apparatus
Assignee: Unisys Corp
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Filing: 1970-12-01
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Granted: 1972-07-18
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Expires: 1990-12-01
Abstract
Abstract A ribbon feeding apparatus having a ratcheted ribbon spool engageable by a reciprocating pawl to incrementally rotate the ribbon spool. A camming lug operatively coupling the pawl and responsive to the diameter of the ribbon on the spool inversely varies the increment of angular engagement of the pawl with the ratchet wheel as the ribbon diameter increases, thus effecting uniform ribbon feed.
Inventors
- 👤 Campbell Findlay
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 09:09
CPC Classifications
B; B41; B41J; B41J33/00; B41J33/14; B41J33/36; B65; B65H; B65H18/00; B65H18/08; B65H18/10; B65H18/103; B65H18/12
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
138 words
Ribbon feed apparatus including a spool to hold a ribbon or the like, spool supporting means axially and rotatably supporting said spool, a ratchet wheel rigidly fastened to said spool and axially rotatable with said spool, a pawl reciprocably engageable with said ratchet wheel operable with a driving stroke to rotate said spool, wherein the improvement comprises: a camming lug rotatable on a fixed axis relative to said spool, said camming lug variably coupling said pawl with said ratchet by means of the accumulated ribbon on said spool, said camming lug being rideable upon the periphery of the ribbon on said spool and operable on the driving stroke of said pawl to move said pawl into engagement with said ratchet for an angular distance of said spool inversely variable with the diameter of the ribbon on said spool.
Claim 2
Dependent Claim
138 words
Ribbon feed apparatus including a spool to hold a ribbon or the like, spool supporting means axially and rotatably supporting said spool, a ratchet wheel rigidly fastened to said spool and axially rotatable with said spool, a pawl reciprocably engageable with said ratchet wheel operable with a driving stroke to rotate said spool, wherein the improvement comprises: a camming lug rotatable on a fixed axis relative to said spool, said camming lug variably coupling said pawl with said ratchet by means of the accumulated ribbon on said spool, said camming lug being rideable upon the periphery of the ribbon on said spool and operable on the driving stroke of said pawl to move said pawl into engagement with said ratchet for an angular distance of said spool inversely variable with the diameter of the ribbon on said spool.
Claim 3
Dependent Claim
61 words
An apparatus as defined in claim 1 wherein a projection on said camming lug in contact with said pawl moves said pawl away from said ratchet wheel as the diameter of the ribbon on said spool increases, said movement serving to reduce the angular distance of said engagement of said pawl with said ratchet during the driving stroke of said pawl.
Claim 4
Dependent Claim
24 words
An apparatus as defined in claim 1 wherein said camming lug is biased in contact with the periphery of the ribbon on said spool.
Claim 5
Dependent Claim
91 words
In a ribbon feed and reverse mechanism operably associated with a printing device, said mechanism having a pair of spaced-apart rotatable ratcheted spools, a pair of pawls operably associated with said pair of spools, and pawl driving means effective for alternately winding a ribbon onto each of said pair of spools, pivotably mounted means coupled with said pawl means for inversely varying the speed of ribbon winding as the diameter of the ribbon wound on either spool increases, said pivotally mounted means being rotatable on fixed axes relative to said spools.
Claim 6
Dependent Claim
91 words
In a ribbon feed and reverse mechanism operably associated with a printing device, said mechanism having a pair of spaced-apart rotatable ratcheted spools, a pair of pawls operably associated with said pair of spools, and pawl driving means effective for alternately winding a ribbon onto each of said pair of spools, pivotably mounted means coupled with said pawl means for inversely varying the speed of ribbon winding as the diameter of the ribbon wound on either spool increases, said pivotally mounted means being rotatable on fixed axes relative to said spools.
Claim 7
Dependent Claim
113 words
The ribbon feed and reverse mechanism defined in claim 4 wherein said pivotally mounted means for inversely varying the speed of ribbon winding comprises a pair of camming lugs associated with said pair of pawls and each rotatably mounted on a fixed axis relative to its associated ratcheted spool, each of said camming lugs having a camming surface responsive to the periphery of the ribbon wound onto its associated spool, and having a projection cooperably associated with its corresponding pawl, each of said camming lugs being effective to reduce the Angular distance of engagement of its associated pawl with the ratchet of its associated ratcheted spool as said ribbon is drivenly wound thereon.
Claim 8
Dependent Claim
42 words
The ribbon feed and reverse mechanism defined in claim 4 wherein each of said pivotally mounted camming lugs is biased such that its said camming surface is held in contact with the periphery of the ribbon wound onto its associated ratcheted spool.
References Cited (Backward Citations)
US2917250A
Cited
US2800990A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-07-18 | 1976-01-17 | 1976-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-18 | 1980-01-17 | 1980-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-18 | 1984-01-17 | 1984-07-18 | $7700.00 | Window Closed / Lapsed |