Patent US3926294A successfully refreshed from Google Patents.
US3926294A
Expired / Lapsed
US
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Changeable type head
Assignee: SCM Corp
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Filing: 1973-10-10
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Granted: 1975-12-16
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Expires: 1993-10-10
Abstract
Abstract A changeable type head is provided that can be positively locked on a typebar of a typing machine. The changeable type head includes a U-shaped body portion adapted to envelop the rear and side surfaces of the typebar. A lug in the apex of the U-shaped body portion seats in a notch in the rear surface of the typebar. Cooperating with the lug and mating notch is a lever pivotally mounted between the side walls of the U-shaped body portion. The lever has a handle and a cam surface that presses the typebar against the apex of the U when the lever is in a lock position as indicated by upward projection of the handle. The U-shaped body portion is triangular-shaped as viewed from the side to reduce moments of force upon impact of a type character.
Inventors
- 👤 Donald G Bastian
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 21:03
CPC Classifications
B; B41; B41J; B41J1/00; B41J1/04; Y; Y10; Y10T; Y10T403/00; Y10T403/70; Y10T403/7062; Y10T403/7064; Y10T403/7066; Y10T403/7071
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
256 words
In a changeable type head of the type having rear and side walls for enveloping rear and side surfaces, respectively, of a typebar; at least one type character on an exterior surface of the rear wall of the changeable type head; and means for blocking longitudinal movement of the changeable type head on the typebar; the improvement comprising, in combination: a. a pivot spanning the side walls of the changeable type head, substantially perpendicular to the side walls, and in front of the typebar; b. a lever on the pivot; c. a lock surface on the lever, the lock surface farther than a mating front surface of the typebar from the pivot when the typebar is against the rear wall of the changeable type head; d. a release surface on the lever, the release surface closer than the mating front surface of the typebar to the pivot when the typebar is against the rear wall of the changeable type head; and e. a handle on an opposite end of the lever from the lock surface for pivoting the lever so that the lock surface faces the typebar to lock the changeable type head on the typebar in cooperation with the blocking means and for pivoting the lever so that the release surface faces the typebar to release the changeable type head from the typebar; and f. an overcenter surface on the lever, the overcenter surface farther than the lock surface from the pivot and located between the release and lock surface to provide an overcenter effect.
Claim 2
Dependent Claim
256 words
In a changeable type head of the type having rear and side walls for enveloping rear and side surfaces, respectively, of a typebar; at least one type character on an exterior surface of the rear wall of the changeable type head; and means for blocking longitudinal movement of the changeable type head on the typebar; the improvement comprising, in combination: a. a pivot spanning the side walls of the changeable type head, substantially perpendicular to the side walls, and in front of the typebar; b. a lever on the pivot; c. a lock surface on the lever, the lock surface farther than a mating front surface of the typebar from the pivot when the typebar is against the rear wall of the changeable type head; d. a release surface on the lever, the release surface closer than the mating front surface of the typebar to the pivot when the typebar is against the rear wall of the changeable type head; and e. a handle on an opposite end of the lever from the lock surface for pivoting the lever so that the lock surface faces the typebar to lock the changeable type head on the typebar in cooperation with the blocking means and for pivoting the lever so that the release surface faces the typebar to release the changeable type head from the typebar; and f. an overcenter surface on the lever, the overcenter surface farther than the lock surface from the pivot and located between the release and lock surface to provide an overcenter effect.
Claim 3
Dependent Claim
16 words
The changeable type head of claim 1, in which the lever is composed of a plastic.
Claim 4
Dependent Claim
31 words
The changeable type head of claim 1, in which top and bottom surfaces of the side walls of the changeable type head taper toward the front of the changeable type head.
Claim 5
Dependent Claim
32 words
The changeable type head of claim 3, further comprising: f. means for stopping movement of the release surface on the lever away from the typebar when the lock surface faces the typebar.
Claim 6
Dependent Claim
27 words
The changeable type head of claim 4, in which the stopping means includes a portion of the handle that overlaps at least one of the side walls.
Claim 7
Dependent Claim
29 words
The changeable type head of claim 3, further comprising: f. means for latching the lever when the lock surface faces the typebar to prevent pivotal movement of the lever.
Claim 8
Dependent Claim
30 words
The changeable type head of claim 6, in which the latching means includes a latch on the handle and a mating recess in at least one of the side walls.
References Cited (Backward Citations)
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-15 | 1979-06-16 | 1979-12-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-15 | 1983-06-16 | 1983-12-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-15 | 1987-06-16 | 1987-12-16 | $7700.00 | Window Closed / Lapsed |