Patent US4034821A successfully refreshed from Google Patents.
US4034821A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Motorcycle chain drive
Assignee: Individual
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Filing: 1976-06-09
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Granted: 1977-07-12
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Expires: 1996-06-09
Abstract
Abstract An improvement in a chain drive mechanism wherein a drive sprocket is connected to a spaced driven sprocket by an endless chain with the driven sprocket being pivoted on a swing arm about an axis intermediate the two sprockets. The improvement includes idler members on opposite sides of the pivot axis for engaging and "pinching" the chain flights together at points equidistant from the pivot axis. Through this arrangement, pivotal movement of the driven sprocket about the axis is resisted, since leverage is applied through the idler members and all moments operating about the pivot axis are greatly reduced and applied in a direction opposite to the pivotal movement of the driven sprocket. There is therefore a tendency for the swing arm to seek an equalized condition.
Inventors
- 👤 Richard B. Stoddard
- 👤 Harold T. Stoddard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 14:13
CPC Classifications
B; B62; B62M; B62M9/00; B62M9/16; F; F16; F16H; F16H7/00; F16H7/08; F16H2007/0863; F16H2007/0874
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
118 words
In a powered wheel vehicle having a drive mechanism including a drive sprocket, a driven sprocket, an endless chain directly interconnecting the drive and driven sprockets and a swing arm means pivotably mounting the driven sprocket to the vehicle for about a transverse pivot axis located between the drive sprocket and driven sprocket axes; an improvement comprising: first idler means above the pivot axis for engaging the endless chain from above its upper flight; second idler means below the pivot axis for engaging the endless chain from below its lower flight; wherein the first and second idler means are located so as to engage the chain flights at positions diametrically opposed to one aother through the pivot axis.
Claim 2
Dependent Claim
118 words
In a powered wheel vehicle having a drive mechanism including a drive sprocket, a driven sprocket, an endless chain directly interconnecting the drive and driven sprockets and a swing arm means pivotably mounting the driven sprocket to the vehicle for about a transverse pivot axis located between the drive sprocket and driven sprocket axes; an improvement comprising: first idler means above the pivot axis for engaging the endless chain from above its upper flight; second idler means below the pivot axis for engaging the endless chain from below its lower flight; wherein the first and second idler means are located so as to engage the chain flights at positions diametrically opposed to one aother through the pivot axis.
Claim 3
Dependent Claim
23 words
The combination set out by claim 1 wherein the first idler means is mounted to said swing arm means for pivotaL movement therewith.
Claim 4
Dependent Claim
23 words
The combination set out by claim 1 wherein the second idler means is mounted to said swing arm means for pivotal movement therewith.
Claim 5
Dependent Claim
38 words
The combination set out by claim 1 wherein the first and second idler means are comprised of free wheeling idler sprockets with rotational axes lying in a plane passing through the pivot axis of the swing arm mean.
Claim 6
Dependent Claim
23 words
The combination set out by claim 2 wherein the second idler means is mounted to said swing arm means for pivotal movememt therewith.
Claim 7
Dependent Claim
37 words
The combination set out by claim 5 wherein first and second idler means are comprised of free wheeling idler sprockets with rotational axes lying in a plane passing through the pivot axis of the swing arm means.
Claim 8
Dependent Claim
25 words
The improvement set out by claim 1 wherein the first and second idler means tangentially engage chain at locations spaced equally from the pivot axis.
Claim 9
Dependent Claim
26 words
The improvement set out by claim 5 wherein the first and second idler means tangentially engage the chain at locations spaced equally from the pivot axis.
Claim 10
Dependent Claim
38 words
The combination set out by claim 8 wherein the first and second idler means are comprised of free wheeling idle sprockets with rotational axes lying in a plane passing through the pivot axis of the swing arm means.
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) | 1980-07-11 | 1981-01-10 | 1981-07-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-07-11 | 1985-01-10 | 1985-07-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-07-11 | 1989-01-10 | 1989-07-12 | $7700.00 | Window Closed / Lapsed |