US3795321A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Telescoping crane boom
Assignee: CENTURY II Inc A CORP OF
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Filing: 1972-05-18
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Granted: 1974-03-05
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Expires: 1992-05-18
Abstract
Abstract Means and method for extending a telescopic crane boom section of a mobile crane that does not have its own extending cylinder are disclosed. The crane boom comprises four tubular telescopic sections, namely, a first fly section, second and third sections, and a fourth base section. First and second linearly extendable hydraulic rams are located within the boom. The first ram is connected between the base section and the third section to effect movement of the latter. The second ram is connected between the third and second sections to effect movement of the latter. For road transport conditions, the fly section is detachably connected to the second section. To set up the crane for operation, the first ram is used to partially extend the three movable sections. Then the second ram is used to further extend the first two sections. The first ram is then temporarily attached to the fly section and the fly section is disconnected from the second section. The second ram is then used to retract the second section, the fly section is then connected to the second section in fully extended position, and the first ram is then disconnected from the fly section. Both rams are now in readiness to independently operate the second and third sections, with the fly section fully extended on the second section.
Inventors
- 👤 R Johnston
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 18:49
CPC Classifications
B; B66; B66C; B66C23/00; B66C23/62; B66C23/64; B66C23/70; B66C23/701; B66C23/705
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
217 words
In a telescopic boom having a fly section, a second section, a third section and a base section, said third section being provided with at least one access hole therein, said second section being provided with a pinning hole near its outer end and with two spaced apart access holes, and said fly section being provided with pinning holes, one near each end and with another pinning hole intermediate thereof, a first extendable and retractable hydraulic actuator comprising two relatively movable portions, one portion being connected to the inner end of said base section and the other portion being connected to the inner end of said third section, a second extendable and retractable hydraulic actuator comprising two relatively movable portions, one portion being connected to the inner end of said third section and the other portion connected to the inner end of said second section, first means for releasably connecting said fly section and said second section with the former retracted within the latter, second means for releasably connecting said other portion of said first actuator to the inner end of said fly section, and third means for releasably connecting said fly section and said second section to each other with the former extended from the latter, said first, second and third means comprising removable pin means.
Claim 2
Dependent Claim
217 words
In a telescopic boom having a fly section, a second section, a third section and a base section, said third section being provided with at least one access hole therein, said second section being provided with a pinning hole near its outer end and with two spaced apart access holes, and said fly section being provided with pinning holes, one near each end and with another pinning hole intermediate thereof, a first extendable and retractable hydraulic actuator comprising two relatively movable portions, one portion being connected to the inner end of said base section and the other portion being connected to the inner end of said third section, a second extendable and retractable hydraulic actuator comprising two relatively movable portions, one portion being connected to the inner end of said third section and the other portion connected to the inner end of said second section, first means for releasably connecting said fly section and said second section with the former retracted within the latter, second means for releasably connecting said other portion of said first actuator to the inner end of said fly section, and third means for releasably connecting said fly section and said second section to each other with the former extended from the latter, said first, second and third means comprising removable pin means.
Claim 3
Dependent Claim
106 words
A boom according to claim 1 wherein the outer end of said first actuator is provided with a pinning hole and wherein, when the access hole in said third section is aligned with the access hole nearer the inner end of said second section when the pinning holes near the outer ends of the fly section and the second section are aligned, the pinning hole near the inner end of said fly section is aligned with said pinning hole in said first actuator and is accessible through the access hole in said third section and the access hole nearer the inner end of said second section.
Claim 4
Dependent Claim
70 words
A boom according to claim 2 wherein, when the pinning hole near the outer end of the second section is aligned with the intermediate pinning hole of said fly section, the primary hole near the inner end of said fly section is accessible through the access hole in said third section and through the access hole in the second section which is nearer the outer end of the second section.
Claim 5
Dependent Claim
280 words
In a telescopic boom having a fly section, a second section, a third section and a base section, said third section being provided with at least one access hole therein, said second section being provided with a pinning hole near its outer end and with two spaced apart access holes, and said fly section being provided with pinning holes, one near each end and with another pinning hole intermediate thereof, a first extendable and retractable hydraulic actuator connected between the inner end of said base section and the inner end of said third section, said first actuator being provided with a pinning hole, a second extendable and retractable hydraulic actuator connected between the inner end of said third section and the inner end of said second section, first means comprising removable pin means for releasably connecting said fly section and said second section with the former retracted within the latter, second means comprising removable pin means for releasably connecting said first actuator to the inner end of said fly section, and third means comprising removable pin means for releasably connecting said fly section and said second section with the former extended from the latter, and wherein when the access hole in said third section is aligned with the access hole nearer the inner end of said second section when the pinning holes near the outer ends of the fly section and the second section are aligned, the pinning hole near the inner end of said fly section is aligned with said pinning hole in said first actuator and is accessible through the access hole in said third section and the access hole nearer the inner end of said second section.
Claim 6
Dependent Claim
280 words
In a telescopic boom having a fly section, a second section, a third section and a base section, said third section being provided with at least one access hole therein, said second section being provided with a pinning hole near its outer end and with two spaced apart access holes, and said fly section being provided with pinning holes, one near each end and with another pinning hole intermediate thereof, a first extendable and retractable hydraulic actuator connected between the inner end of said base section and the inner end of said third section, said first actuator being provided with a pinning hole, a second extendable and retractable hydraulic actuator connected between the inner end of said third section and the inner end of said second section, first means comprising removable pin means for releasably connecting said fly section and said second section with the former retracted within the latter, second means comprising removable pin means for releasably connecting said first actuator to the inner end of said fly section, and third means comprising removable pin means for releasably connecting said fly section and said second section with the former extended from the latter, and wherein when the access hole in said third section is aligned with the access hole nearer the inner end of said second section when the pinning holes near the outer ends of the fly section and the second section are aligned, the pinning hole near the inner end of said fly section is aligned with said pinning hole in said first actuator and is accessible through the access hole in said third section and the access hole nearer the inner end of said second section.
Claim 7
Dependent Claim
70 words
A boom according to claim 4, wherein, when the pinning hole near the outer end of the second section is aligned with the intermediate pinning hole of said fly section, the primary hole near the inner end of said fly section is accessible through the access hole in said third section and through the access hole in the second section which is nearer the outer end of the second section.
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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) | 1977-03-04 | 1977-09-03 | 1978-03-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-03-04 | 1981-09-03 | 1982-03-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-03-04 | 1985-09-03 | 1986-03-05 | $7700.00 | Window Closed / Lapsed |