Patent US3872950A successfully refreshed from Google Patents.
US3872950A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Vibration damper for tractor roll-bar
Assignee: Case Poclain Corp Ltd
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Filing: 1973-07-02
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Granted: 1975-03-25
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Expires: 1993-07-02
Abstract
Abstract Roll-bar, safety frame and cab structures of agricultural tractors tend to vibrate badly around specific engine speeds. Such structures include at least one transverse tubular frame member within which a metal bar is suspended by rubber pads, the required degree of compression of which is achieved by the use of shims. The mass of the bar is carefully determined so that when vibration occurs in the structure including the tubular frame member, the bar also vibrates but the periodicity of the two vibrations is such that they tend to cancel each other out.
Inventors
- 👤 Herbert Edward Ashfield
- 👤 Stephen Moorhouse
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 22:47
CPC Classifications
B; B60; B60R; B60R21/00; B60R21/02; B60R21/13; B60R21/131; F; F16; F16F; F16F7/00; F16F7/10; F16F7/104; F16F7/108
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
114 words
In a safety structure for an agricultural tractor having an engine and a supporting structure mounted on ground engaging wheels drive connected to said engine, said safety structure being in the form of a roll bar or bars, a safety frame or a cab structure or the like, said safety structure including frame means effectively fixed with respect to said supporting structure and protectively surrounding the driver of the tractor, the improvement in said frame means comprising at least one nonrotatable hollow frame member within which is mounted resilient means and a vibration damping mass suspended by said resilient means for damping vibrations set up in said safety structure as at certain engine speeds.
Claim 2
Dependent Claim
114 words
In a safety structure for an agricultural tractor having an engine and a supporting structure mounted on ground engaging wheels drive connected to said engine, said safety structure being in the form of a roll bar or bars, a safety frame or a cab structure or the like, said safety structure including frame means effectively fixed with respect to said supporting structure and protectively surrounding the driver of the tractor, the improvement in said frame means comprising at least one nonrotatable hollow frame member within which is mounted resilient means and a vibration damping mass suspended by said resilient means for damping vibrations set up in said safety structure as at certain engine speeds.
Claim 3
Dependent Claim
14 words
A safety structure according to claim 1, wherein the member is a transverse tube.
Claim 4
Dependent Claim
14 words
A safety structure according to claim 1, wherein the mass is a metal bar.
Claim 5
Dependent Claim
14 words
A safety structure according to claim 1, wherein the resilient means are rubber pads.
Claim 6
Dependent Claim
52 words
A safety structure according to claim 1, wherein the mass and the resilient means are located within the member by resilient means of metal tabs secured to the member and bent into operative position to close the ends of the member after the location of the mass and the resilient means therein.
Claim 7
Dependent Claim
31 words
A safety structure according to claim 1, wherein shims are interposed between said hollow frame member and said resilient means, to give a required degree of compression of said resilient means.
Claim 8
Dependent Claim
41 words
A safety structure according to claim 1, wherein the member is compressed in the region of the resilient means, after the location of the mass and the resilient means therein, to give a required degree of compression of the resilient means.
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) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |