Patent US3894468A successfully refreshed from Google Patents.
US3894468A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stringed instrument with sliding variably spaced frets
Assignee: Individual
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Filing: 1974-08-23
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Granted: 1975-07-15
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Expires: 1994-08-23
Abstract
Abstract The invention comprises a stringed instrument of the type having an elongated neck normally provided with spaced frets and has a fret block slideably mounted on the neck with several frets thereon to replace the usual frets. The fret block includes means to move the frets longitudinally along the fret block relative to one another as a function of the position of the fret block on the neck, so that as the block slides on the neck the appropriate non-uniform spacing between frets is maintained at any position along the neck to correspond with the varied fret spacing along the neck of an ordinary stringed instrument.
Inventors
- 👤 Philip A Dunlap
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 21:46
CPC Classifications
G; G10; G10D; G10D1/00; G10D1/04; G10D1/05; G10D3/00; G10D3/06
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
95 words
A stringed musical instrument having an elongated neck and a plurality of generally parallel strings spaced from said neck and extending along the longitudinal direction of said neck; a block mounted on said neck to slide in said longitudinal direction along said neck, said block having a plurality of frets mounted thereon transversely of said longitudinal direction and movable relative to said block in longitudinal direction; means responsive to movement of said block along said neck to vary the spacing between said frets as a function of the position of said block on said neck.
Claim 2
Dependent Claim
95 words
A stringed musical instrument having an elongated neck and a plurality of generally parallel strings spaced from said neck and extending along the longitudinal direction of said neck; a block mounted on said neck to slide in said longitudinal direction along said neck, said block having a plurality of frets mounted thereon transversely of said longitudinal direction and movable relative to said block in longitudinal direction; means responsive to movement of said block along said neck to vary the spacing between said frets as a function of the position of said block on said neck.
Claim 3
Dependent Claim
15 words
Structure according to claim 1 and including a fret immovably fixed to said mounting block.
Claim 4
Dependent Claim
34 words
Structure according to claim 2 wherein the number of movable frets is four whereby, in conjunction with said immovable fret five frets, are provided to accommodate the normal span of the hand when chording.
Claim 5
Dependent Claim
92 words
A stringed musical instrument as in claim 1 wherein said neck is attached to an instrument body on one end and a tuning board on the other end, and said means comprises coacting block means and neck structure, said neck structure spanning the substantial length of said neck and consecutive portions of said structure being varied according to the positions thereof on said neck to coact with said block means for increasing the fret spacing as said block approaches the tuning board and decreasing said spacing as said block approaches said body.
Claim 6
Dependent Claim
78 words
Structure according to claim 4 wherein said structure on said neck comprises two longitudinally extended divergent grooves and said block means includes a plurality of spacer pairs tracking in said grooves, and each of said movable frets is mounted on a sliding plate having angled edges and being alternately disposed on said neck with said spacer pairs and bearing on the latter, such that convergence of the individual spacers in each pair causes the separation of adjacent plates.
Claim 7
Dependent Claim
13 words
Structure according to claim 5 and including means to bias said plates together.
Claim 8
Dependent Claim
35 words
Structure according to claim 5 wherein said block includes a panel mounted between said plates and said frets, said panel having longitudinal slots therein and said frets are mounted to said plates through said slots.
Claim 9
Dependent Claim
28 words
Structure according to claim 7 wherein said neck has a pair of longitudinal tracks engaging the opposing edges of said panel in slidably mounted relationship on said neck.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-07-14 | 1979-01-13 | 1979-07-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-07-14 | 1983-01-13 | 1983-07-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-07-14 | 1987-01-13 | 1987-07-15 | $7700.00 | Window Closed / Lapsed |